nils-herrmann/clean_scirepeval huggingface dataset:
Research on Adsorption of Pb~(2+) from Aqueous Solutions Using Polypyrrole/Nylon 6 Nanofibers Mat

Polypyrrole/Nylon 6 core-shell Nanofibers mat(PPy/Nylon 6-NFSM),prepared via situ polymerization on nylon6 electrospun nanofibers mat template,was used as an adsorbent to remove Pb~(2+) from aqueous solutions.To study the adsorption characteristics of PPy/Nylon 6-NFSM on Pb~(2+),the work focused on two parts,dynamic adsorption and static adsorption.The investigation explored the possibility of PPy/Nylon 6-NFSM as an efficient solid phase extraction(SPE) adsorbent for the separation and enrichment of trace Pb~(2+) in water samples.The experiment results showed that the maximum static adsorption capacity of PPy/Nylon 6-NFSM for Pb~(2+) was 542.1 mg/g at 298 K in pH=10 solution.The adsorption process could be well fitted with the pseudo-second-order kinetic model,the adsorption equilibrium data accorded with Freundlich isotherm model.Under the optimum conditions,PPy/Nylon 6-NFSM was used as adsorbent in SPE coupled with Flame atomic spectrophotometer(AA-7000) for the determination of Pb~(2+) in water samples.The limits of detection of the method were 1.2 μg/L(S/N=3),the recoveries of spiked water samples at concentration of 10 μg/L were 95.3%-100.4%with RSD of 1.6%.The method is accurate and sensitive in detection of trace concentrations of Pb~(2+) in water sample.

Field of study: Chemistry
Current Welfare Reform: A Return to the Principles of 1834

In his Presidential Address of 1992, President Clinton announced his intention of "ending welfare as we know it." That promise has finally come to fruition in principle, if not yet in actual practice, with the passage of The Personal Responsibility and Work Opportunity Reconciliation Act in 1996. The Act proposes to substantially modify the previous welfare system by compelling welfare recipients to accept greater responsibility for their own support by requiring "workfare." Workfare will require them to perform public service, enroll in job training programs, limit the length of time they can receive payments, eliminate payments for additional children born to welfare mothers, and, in some states, drop the able-bodied from the welfare rolls altogether. These are all components of a strategy designed to eventually move able-bodied welfare recipients into the private work force and off public support. These changes follow from widespread acceptance of the belief that the welfare system is responsible for the creation of a dependant class unwilling to accept responsibility for themselves. The view is that members of this "underclass" or "poverty culture" are characterized by and reproduce such social pathologies as crime, drug abuse, and unwed motherhood that prevent its members from active participation in mainstream American life. In addition, the recipients of relief are no longer viewed as having a right to public support [Melville 1994, 19], particularly if they are able-bodied [Aaron 1990, 277]. Reforming, or "ending welfare as we know it," is now seen as being in the best interests of the poor-es "honoring a moral obligation to help poor people help themselves" [Clinton 1996]. Why welfare reform? Why now, and why in this form? The answer, it is argued, can be found in the theme of this conference-"the Great Capitalist Restora-

Field of study: Economics
Structural and Magnetic Properties Evolution of Co-Nd Substituted M-type Hexagonal Strontium Ferrites Synthesized by Ball-Milling-Assisted Ceramic Process

M-type hexagonal Sr1−xCoxNdxFe12−xO19 (x = 0, 0.08, 0.16, and 0.24) has been synthesized by ball milling, followed by calcination in air. The calcined products have been characterized by x-ray powder diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectra, and vibrating sample magnetometry. XRD and SEM analyses confirm the formation of M-type Sr hexaferrite with platelet-like morphology when Sr1−xCoxNdxFe12−xO19 (x = 0, 0.08, 0.16, and 0.24) precursors are calcined at 950°C in air for 2.5 h. Lattice parameters “a” and “c” values of Sr1−xCoxNdxFe12−xO19 reflect a very small variation after doping of Nd3+ and Co2+ ions. Average crystallite size of Sr1−xCoxNdxFe12−xO19 sample, calcined at 1150°C, decreased obviously after doping of Co2+ and Nd3+ ions. This is because the bond energy of Nd3+-O2− is much larger than that of Sr2+-O2−. Magnetic characterization indicates that all the samples exhibit good magnetic properties. Substitution of Sr2+ and Fe3+ ions by Nd3+ and Co2+ ions can improve the specific saturation magnetizations and remanence of Sr1−xCoxNdxFe12−xO19. Sr0.84Co0.16Nd0.16Fe11.84O19, calcined at 1050°C, has the highest specific saturation magnetization value (74.75 ± 0.60 emu/g), remanence (45.15 ± 0.32 emu/g), and magnetic moment (14.34 ± 0.11 μB); SrFe12O19, calcined at 1150°C, has the highest coercivity value (4037.01 ± 42.39 Oe). These magnetic parameters make this material a promising candidate for applications such as high-density magnetic recording and microwave absorbing materials.

Field of study: Materials science
Scattering of Waves by Steel Reinforcement in Concrete

The application of wave-sensing methods to the non-destructive evaluation of concrete structures requires often the use of simple (or at least tractable) models for the solution of the physical problem under consideration. For example, a concrete deck would ideally be represented as a laminated plate. However, steel reinforcement bars embedded in concrete constitute strong scatterers of elastic and acoustic waves of short wavelength. From a rigorous standpoint, this implies that the steel mesh cannot be represented simply as a homogenous layer of material with appropriate physical properties. However, if the wavelengths are not too short and the spacing between rebars not too great, such a strategy is indeed possible. This paper is concerned with the problem of elastic wave scattering by steel reinforcement and examines reflection/transmission patterns of plane waves in a homogeneous mass of concrete reinforced by equidistant steel bars. For this purpose three solutions are used, namely a first order scattering solution, an exact solution, and a solution based on a layered medium with equivalent material properties. It is found that for reasonably long wavelengths, the latter model provides acceptable results.

Field of study: Engineering
Strato-mesospheric ClO observations by SMILES: error analysis and diurnal variation

Chlorine monoxide (ClO) is the key species for anthropogenic ozone losses in the middle atmosphere. We observed ClO diurnal variations using the Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES) on the International Space Station, which has a non-sun-synchronous orbit. This includes the first global observations of the ClO diurnal variation from the stratosphere up to the mesosphere. The observation of mesospheric ClO was possible due to 10–20 times better signal-to-noise (S/N) ratio of the spectra than those of past or ongoing microwave/submillimeter-wave limb-emission sounders. We performed a quantitative error analysis for the strato- and mesospheric ClO from the Level-2 research (L2r) product version 2.1.5 taking into account all possible contributions of errors, i.e. errors due to spectrum noise, smoothing, and uncertainties in radiative transfer model and instrument functions. The SMILES L2r v2.1.5 ClO data are useful over the range from 0.01 and 100 hPa with a total error estimate of 10–30 pptv (about 10%) with averaging 100 profiles. The SMILES ClO vertical resolution is 3–5 km and 5–8 km for the stratosphere and mesosphere, respectively. The SMILES observations reproduced the diurnal variation of stratospheric ClO, with peak values at midday, observed previously by the Microwave Limb Sounder on the Upper Atmosphere Research Satellite (UARS/MLS). Mesospheric ClO demonstrated an opposite diurnal behavior, with nighttime values being larger than daytime values. A ClO enhancement of about 100 pptv was observed at 0.02 to 0.01 hPa (about 70–80 km) for 50° N–65° N from January–February 2010. The performance of SMILES ClO observations opens up new opportunities to investigate ClO up to the mesopause.

Field of study: Environmental science
Detection of opioid receptor mRNA by RT-PCR reveals alternative splicing for the δ- and κ-opioid receptors

The three μ -, δ - and κ -opioid receptors have recently been cloned and characterized at the molecular level. Our analysis of opioid receptor transcripts by RT-PCR revealed two PCR products derived from δ and κ mRNAs with size higher than expected from the known cDNA sequences. DNA sequencing showed additional nucleotides inserted between the known splice sites, indicating the possible existence of alternative splicing pathways for δ and κ receptors. The novel δ -opioid receptor transcript is expressed in mouse brain and contains a 243 bp insertion. This additional sequence is located at the splice junction between the first and second coding exons and is encoded by a single exon located 9 kb upstream exon 2 in the mDOR gene. The other alternative transcript occurs in human monocytic and T lymphocytic cell lines and encodes a novel form of the κ -opioid receptor. The PCR product presents a 23 bp deletion at the 3′ end of exon 2 followed by a 246 bp insertion found between exons 2 and 3. In the hKOR gene, this insertion is encoded by two DNA segments. One of them is located 0.4 kb downstream exon 2 while the second is flanking exon 3 on the 5′ side. Both novel putative δ and κ exons present in-frame stop codons that would lead to truncated receptor proteins. A possible functional or regulatory role of these shorter proteins in opioid function remains to be determined.

Field of study: Biology
The Forestry Crisis as a Crisis of the Rule of Law

The abstract global ideas of sustainable development1 and of the rule of law2 meet in the forests of the tropics, where the absence of viable community forest management institutions is driving deforestation and, therefore, the larger legal and ecological stability of the region. This interaction needs to be better understood by rule of law theorists seeking to discover and implement proper legal structures for development.3 The rule of law effort can be seen either narrowly, as a "thin" program focused on improving the mechanics of courts as well as legislative and administrative bodies, or as a "thick" conception rooted in the belief that such improvements will lead toward a stronger civil society and democracies rooted

Field of study: Law
Better versus worse family therapy sessions as reflected in clients' alliance-related behavior.

To be responsive to clients' evaluations of the unfolding therapy process, therapists must first accurately "read" client behavior, a particularly challenging task in conjoint family therapy. In this study, the authors compared client behavior in 28 sessions that one family member and the therapist concurred, on the Session Evaluation Questionnaire (W. B. Stiles & J. S. Snow, 1984), were relatively better or worse than their other sessions. Client behavior was rated from videotapes using the System for Observing Family Therapy Alliances (SOFTA-o; M. L. Friedlander et al., 2006). In contrast to the worse sessions, the better sessions were characterized by significantly greater client Engagement in the Therapeutic Process and Safety within the Therapeutic System. Notably, whereas only the worse sessions had exceptionally poor within-family collaboration, 40% of the better sessions were characterized by mild family conflict. Implications are discussed for building theory on therapist responsiveness and for future research that may benefit practice, training, and supervision.

Field of study: Psychology
The homomorphic analytic signal

This paper introduces an alternative form of analytic signal that is formed using homomorphic signal processing techniques. It may be generated for signals that demonstrate redundancy in their pole-zero distributions, such as phase signals and real signals. The analytic signal is formed by manipulating the positions of the signal's nonminimum phase poles and zeros to create a minimum phase signal. A factorization of real signals is presented that demonstrates the properties of the homomorphic analytic signal, and a new definition of instantaneous frequency is developed. Examples are given to verify the theory and comparisons with the linear analytic signal, and instantaneous frequency are made.

Field of study: Engineering
A method for the determination of rhodamine b and brilliant sulfaflavine on cotton string collectors and in a spray tank solution mixture

A fluorescent method for the determination of rhodamine B (RhB) and brilliant sulfaflavine (BSF) dual tracers on cotton string collectors and in spray tank solutions was developed for the evaluation of the effects of adjuvants on the atmospheric drift of agricultural sprays. Both tracers on collectors were extracted with deionized water simultaneously and measured directly with a Fluorescent Specrometer by switching the maximum excitation and emission wavelengths. The linear ranges of the RhB and BSF standard curves were 0–50 and 0–10 ppb respectively. Recoveries of tracers on cotton strings ranged from 92.9% ± 1.1% to 95.1% ± 1.0% for RhB and 91.9% ± 2.8% to 103% ± 0.6% for BSF when spiked levels ranged from 0.25 to 2.5 μg per collector. The detection limit of the instrument was approximately 0.1 ppb for both tracers. The detection limits of the analytical method were approximately 0.1 ppb for RhB and 0.3 ppb for BSF when the background levels of cotton strings were subtracted. The presence of o...

Field of study: Agricultural and Food sciences
Microstructure and Thermal Behavior of Al-Ti Multilayer Foils for Micro-bonding

In order to make reactive micro-bonding have a better application, 5 types of Al-Ti reactive multilayer foils with different modulation periods and total thicknesses were fabricated by DC magnetron sputtering system. The microstructure and thermal behavior of the foils were characterized using scanning electron microscope,X-ray diffraction and simultaneous thermal analyzer respectively. The results indicate that the reactivity of nano multilayer foils is apparently higher than that of micron ones. The modulation period is found to have a significant influence on the thermal behavior of high period600 nm. As the period decreasing, the initial reaction temperature of multilayer foils drops, the reaction temperature range lessens and the reaction heat decreases, thus the whole reaction is easier to complete. When the modulation period exceeds600 nm, the reaction of Al-Ti multilayer foils is relatively weak. When the modulation period is less than 300 nm, the reaction becomes strong. In order to realize the low temperature reactive micro-bonding, the modulation period should be controlled around 100 nm.

Field of study: Materials science
Overexpression of TGF-β Inducible microRNA-143 in Zebrafish Leads to Impairment of the Glomerular Filtration Barrier by Targeting Proteoglycans

TGF-β is known as an important stress factor of podocytes in glomerular diseases. Apart from activation of direct pro-apoptotic pathways we wanted to analyze micro-RNA (miRs) driven regulation of components involved in the integrity of the glomerular filtration barrier induced by TGF-β. Since miR-143-3p (miR-143) is described as a TGF-β inducible miR in other cell types, we examined this specific miR and its ability to induce glomerular pathology.  We analyzed miR-143 expression in cultured human podocytes after stimulation with TGF-β. We also microinjected zebrafish eggs with a miR-143 mimic or with morpholinos specific for its targets syndecan and versican and compared phenotype and proteinuria development.  We detected a time dependent, TGF-β inducible expression of miR-143 in human podocytes. Targets of miR-143 relevant in glomerular biology are syndecans and versican, which are known components of the glycocalyx. We found that syndecan 1 and 4 were predominantly expressed in podocytes while syndecan 3 was largely expressed in glomerular endothelial cells. Versican could be detected in both cell types. After injection of a miR-143 mimic in zebrafish larvae, syndecan 3, 4 and versican were significantly downregulated. Moreover, miR-143 overexpression or versican knockdown by morpholino caused loss of plasma proteins, edema, podocyte effacement and endothelial damage. In contrast, knockdown of syndecan 3 and syndecan 4 had no effects on glomerular filtration barrier.  Expression of versican and syndecan isoforms is indispensable for proper barrier function. Podocyte-derived miR-143 is a mediator for paracrine and autocrine cross talk between podocytes and glomerular endothelial cells and can alter expression of glomerular glycocalyx proteins.

Field of study: Biology, Chemistry
[Prognostic significance of indices of platelets aggregation and interleukin-1β in the acute period of ischemic stroke].

To determine the prognostic significance of indices of platelet aggregation (PA) and the level of interleukin IL-1β in the outcome of ischemic stroke (IS).



One hundred and eight patients were studied. According to disease outcome, two groups of patients were identified: survivors (group 1) and patients with fatal outcome (group 2). Patients were examined in the very early stage (the 1st day of hospitalization) and in the early stage (the 7th day of hospitalization) of IS. The level of interleukin IL-1β in blood serum was defined by enzyme immunoassay method. PA was measured by nephelometric method.



According to PA indices, a posteriori prognosis of fatal outcome was 10%, but according to IL-1β indices, it was 0.90%. Consequently, the prognostic significance of PA indices with regard to fatal outcome of IS patients in the acute period is higher than that of IL-1b indices. Taking into consideration the expenses of both methods of diagnosis, the authors conclude that with regard to economic availability, PA measurement as a prognostic-diagnostic method is more acceptable in clinical practice.

Field of study: Medicine, Psychology
The opportunity cost of exercise: do higher-earning Australians exercise longer, harder, or both?

Despite the widely documented benefits of exercise, very little is known about how individuals make the decision on exercise. In particular, the decision on the intensity of exercise has attracted only one US study to date, which tests the hypothesis that individuals shift toward less time-intensive but more physically intensive forms of exercise as their wages increase. In this article, we revisit this hypothesis by employing a more credible empirical framework. Studying Australian data we confirm that higher-income Australians tend to exercise more frequently with a longer duration and a higher intensity of exercise. Exercise regimens individualised based on the behavioural patterns of exercise across socio-economic groups will contribute to the efficiency and efficacy of the exercise promotion.

Field of study: Medicine, Political science
Sharp Bias-variance Tradeoffs of Hard Parameter Sharing in High-dimensional Linear Regression

Hard parameter sharing for multi-task learning is widely used in empirical research despite the fact that its generalization properties have not been well established in many cases. This paper studies its generalization properties in a fundamental setting: How does hard parameter sharing work given multiple linear regression tasks? We develop new techniques and establish a number of new results in the high-dimensional setting, where the sample size and feature dimension increase at a fixed ratio. First, we show a sharp bias-variance decomposition of hard parameter sharing, given multiple tasks with the same features. Second, we characterize the asymptotic bias-variance limit for two tasks, even when they have arbitrarily different sample size ratios and covariate shifts. We also demonstrate that these limiting estimates for the empirical loss are incredibly accurate in moderate dimensions. Finally, we explain an intriguing phenomenon where increasing one task's sample size helps another task initially by reducing variance but hurts eventually due to increasing bias. This suggests progressively adding data for optimizing hard parameter sharing, and we validate its efficiency in text classification tasks.

Field of study: Computer science
Postbuckling analysis using a general purpose code

A new capability for solving postbuckling problems in shell structures is described. The matrix theory to adapt Newton's method to nonlinear finite element shell analysis is outlined first. The matrix theory is directed at writing consistent linear algebratic equations for problems where the tangent stiffness matrix is singular or nearly singular. The matrix theory suggests a change of variables as part of the usual iterative procedure in Newton's method. The change of variables is shown to be feasible for introduction into the algorithm programmed in general purpose codes for finite element analysis of structures. Numerical results from a new option that has been programmed in an existing general purpose code are presented. The analysis of shell structures for collapse and for branching at bifurcation loads is illustrated by the numerical examples.

Field of study: Physics
Immediate reinforcement in delayed reward learning in pigeons.

Pigeons were trained on simultaneous red-green discrimination procedures with delayed reward and sequences of stimuli during the delay. In Experiment 1, three stimuli appeared during the 60-second intervals between the correct responses and reward, and the incorrect responses and nonreward. The stimulus that immediately followed a correct response also preceded nonreward, and the stimulus that followed an incorrect response preceded reward. These stimuli were 10 or .33 second in duration for different groups. Stimuli during the remainder of the delay interval differed following correct and incorrect responses. Group 10 initially persisted in the nonrewarded choice, but shifted to a preponderance of rewarded responses after further training. Group .33 rapidly acquired the correct response. Similar results were obtained in Experiment 2 where delay intervals consisted of opposite sequences of two stimuli of equal duration and total delays were 6, 20, or 60 seconds. Early in training, generalization of differential conditioned-reinforcing properties from the conditions preceding reward and nonreward to postchoice conditions had a greater effect relative to backchaining than it did later. It was concluded that delayed-reward learning is best analyzed in terms of the conditioned-reinforcing value of the patterns of cues that follow immediately after rewarded and nonrewarded responses.

Field of study: Biology, Psychology
The end of the ice age

Methane-gas hydrates may have contributed to the rapid rise in atmospheric CH4, CO2, and global temperatures at the end of the last major glaciation about 13 500 years ago. Given suitable orbital conditions and insolation at high latitude, a small triggering event, such as the release of one or more Arctic gas pools, may have initiated massive release of methane from hydrate under ice and in permafrost. The consequent greenhouse warming would have provided strong positive feedback, amplifying emission. This warming, driven by CH4, may have induced the release of CO2 from the oceans to the biosphere, stabilizing the interglacial carbon cycle.

Field of study: Environmental science