nils-herrmann/clean_scirepeval huggingface dataset:
The chemical looping heat pump: Thermodynamic modeling

The need for more energy efficient heating and cooling technologies will increase over the coming decades. Climatic concerns associated with greenhouse gas emissions as well as energy costs associated with powering heating and cooling systems necessitate more efficient systems. This work presents an alternative to traditional vapor compression cycles used for heating and cooling. The chemical looping heat pump system is an indirect chemical heat pump that utilizes the possibility of condensation after a chemical reaction to allow the working fluid's compression to take place in the liquid phase. A thermodynamic model of the cycle is developed using electrochemical cells as the reaction drivers of the cycle. Sensitivity analysis is used to identify the most critical components of the system. The chemical looping heat pump may provide a potential COP increase of over 20% when compared to traditional vapor compression systems for representative device efficiencies.

Field of study: Engineering
Positive and negative regulation of IL-2 gene expression: role of multiple regulatory sites.

Interleukin 2 (IL-2) is an important lymphokine required in the process of T cell activation, proliferation, clonal expansion and differentiation. The IL-2 gene displays both T cell specific and inducible expression: it is only expressed in CD4+ T cells after antigenic or mitogenic stimulation. Several cis-acting regulatory sites are required for induction of the IL-2 gene after stimulation. In this study, we have analysed the function of these cis-acting regulatory sites in the context of the native IL-2 enhancer and promoter sequence. The results of this study suggest that the NFAT (-276 to -261), the distal octamer (-256 to -248) and the proximal octamer (-75 to -66) sites not only act as enhancers of IL-2 gene transcription in the presence of cellular stimulation, but also have a silencing effect on IL-2 gene expression in resting cells. Two other sites display disparate effects on IL-2 gene expression in different T leukemia cell lines: the distal purine box (-291 to -277) and the proximal purine box sites (-145 to -128). Finally, the AP-1 (-186 to -176) and the kappa B sites (-206 to -195) respond to different cellular activation in EL4 cells. The AP-1 site mediated the response to PMA stimulation while the kappa B site responded to IL-1 stimulation. These data suggest that the regulation of IL-2 gene expression is a complex process and multiple cis-acting regulatory sites interact to exert different effects in T cells representative of alternative stages of differentiation.

Field of study: Medicine
Phosphorus Effects of Mesoporous Bioactive Glass on Occlude Exposed Dentin

In recent studies, sealing of exposed dentinal tubules is generally considered as one of the most effective strategies to treat dentin hypersensitivity. Mesoporous bioactive glass (MBG) is a potential material for treating dentin hypersensitivity due to its highly specific areas for dissolution and re-precipitated reaction for reduction in dentin permeability. The groups of commercial products of PerioGlas®, synthetic MBG and MBG without phosphorus (MBGNP) were compared. The MBG and MBGNP powders were prepared by the sol-gel method and mixed with different calculated ratios of phosphoric acid (PA) and then was brushed onto dentin surfaces. We used X-ray diffractometer (XRD), scanning electronic microscope (SEM), and Fourier transform infrared spectroscopy (FTIR) to investigate the physiochemistry and the occlusion ability of dentinal tubules. The results showed that MBG paste mixed with PA solution has a better ability for occluding dentinal tubules than MBGNP; it has a short reaction time and good operability. The major crystallite phase of MBG agents was monocalcium phosphate monohydrate [Ca(H2PO4)2·H2O] in the early stages of the reactions. MBG pastes that were mixed with 30% and 40% PA had the ability to create excellent penetration depth greater than 80 μm. These agents have the potential to treat dentin hypersensitivity.

Field of study: Materials science
Functional expression and characterisation of human cytochrome P45017α in Pichia pastoris

Human cytochrome P45017alpha (CYP17), present in mammalian adrenal and gonadal tissues, catalyses both steroid 17-hydroxylation and C17,20 lyase reactions, producing intermediates for the glucocorticoid and androgenic pathways, respectively. The characterisation of this complex enzyme was initially hampered due to low level in vivo expression of CYP17. Heterologous expression systems have contributed greatly to our current knowledge of CYP17's dual catalytic activity. However, due to the hydrophobic nature of this membrane-bound protein, primarily truncated and modified forms of CYP17 are currently being expressed heterologously. Although the N-terminally modified enzyme has been well characterised, protein structure and function studies still necessitate the expression of unmodified, wild-type CYP17. We report here the expression of a catalytically active, unmodified human CYP17 in the industrial methylotrophic yeast, Pichia pastoris. A typical P450 carbon monoxide difference spectrum, with an absorption maximum at 448nm and a substrate-induced type I spectrum were recorded using a detergent-solubilised cellular fraction containing CYP17. The expressed enzyme catalysed the conversion of progesterone to 17-hydroxyprogesterone as well as 16-hydroxyprogesterone, a product unique to human and chimpanzee CYP17. This is the first report showing the heterologous expression of a fully functional human steroidogenic cytochrome P450 enzyme in P. pastoris.

Field of study: Biology, Engineering
Energy-dependent dead-time correction in digital pulse processors applied to silicon drift detector's X-ray spectra.

Dead-time effects in X-ray spectra taken with a digital pulse processor and a silicon drift detector were investigated when the number of events at the low-energy end of the spectrum was more than half of the total, at counting rates up to 56 kHz. It was found that dead-time losses in the spectra are energy dependent and an analytical correction for this effect, which takes into account pulse pile-up, is proposed. This and the usual models have been applied to experimental measurements, evaluating the dead-time fraction either from the calculations or using the value given by the detector acquisition system. The energy-dependent dead-time model proposed fits accurately the experimental energy spectra in the range of counting rates explored in this work. A selection chart of the simplest mathematical model able to correct the pulse-height distribution according to counting rate and energy spectrum characteristics is included.

Field of study: Physics
Current research situation and prospect of microorganism response to polycyclic aromatic hydrocarbons contaminated soil

Polycyclic aromatic hydrocarbons(PAHs) are the most persistent organic pollutants with strong carcinogenic,teratogenic and mutagenic effect in soil.Soil microbe can not only degrade organic pollutants and restore contaminated soil,but also sensitively reflect the changes of soil environment quality,thus widely applied in bioremediation and bio-indicator of soil pollution.Microbial degradation and restoration of organic pollutants contaminated soil,and the microbial indicators of soil environment quality were summarized in this paper.Present research situations including soil microbial activity and diversity as the indicators of PAHs polluted soil;screening of highly efficient degradation bacteria and microbial degradation pathway,as well as the remediation technology and methods of PAHs contaminated soil were discussed.According to the problems existing in the present studies,the future research prospect was advocated to provide critical facts for exploring response and remediation mechanism of soil micro-organism to PAHs contaminated soil.

Field of study: Agricultural and Food sciences
INTEGRABLE MODULES FOR AFFINE LIE SUPERALGEBRAS

Irreducible nonzero level modules with finite-dimensional weight spaces are discussed for nontwisted affine Lie superalgebras. A complete classification of such modules is obtained for superalgebras of type A(m, n) and C(n)^ using Mathieu's classification of cuspidal modules over simple Lie algebras. In other cases the classification problem is reduced to the classification of cuspidal modules over finite-dimensional cuspidal Lie superalgebras described by Dimitrov, Mathieu and Penkov. Based on these results a complete classification of irreducible integrable (in the sense of Kac and Wakimoto) modules is obtained by showing that any such module is of highest weight, in which case the problem was solved by Kac and Wakimoto.

Field of study: Mathematics
Spatial and temporal analysis of non-steady elongation of rice leaves.

A precise knowledge of the temporal and spatial distributions of cell division and tissue expansion is essential for appropriate leaf sampling in omics studies and for analyses of plant-environment relations. Elongating leaves of rice were studied during their whole development for elongation rate, distribution of cell length, cell production rate and spatial distribution of growth in the leaf. In seven genotypes, the pattern of leaf elongation rate followed three phases: (1) an exponential increase before leaf appearance; (2) a short phase (2-4 d at 20 degrees C) with a stable leaf elongation rate around leaf appearance; and (3) a phase of 8-10 d with a progressive decrease in elongation rate. The profile of cell length along the leaf changed with time during the first and last phases, but was time invariant around appearance. We propose a method adapted to non-steady elongation based on anatomical measurements, which was successfully tested by comparing it with the pricking method. It allowed analysis of the change with time in the spatial distribution of growth from initiation to end of leaf growth. The length of leaf zones with cell division and tissue elongation varied with time, with maximums of 21 and 60 mm respectively around leaf appearance.

Field of study: Environmental science
Disruption of operant oral self-administration of ethanol, sucrose, and saccharin by the AMPA/kainate antagonist, NBQX, but not the AMPA antagonist, GYKI 52466.

AMPAergic transmission has been suggested to be important in mediating the rewarding effects of drugs. We therefore examined the role of non-NMDA glutamate-receptors in mediating the reinforcing properties of ethanol in an oral self-administration paradigm.



The competitive antagonist NBQX (2,3-dihydroxy-6-nitro-7-sulfamoylbenzo(f)quinoxaline) and the non-competitive antagonist, GYKI 52466 (1-(4-aminophenyl)-4-methyl-7,8-methylene-dioxy-5H2,3- be nzodiazepine), were administered to animals previously trained to self-administer ethanol, sucrose, or saccharin, on a progressive ratio schedule.



GYKI 52466 (5 & 10 mg/kg) had no effect on operant responding for ethanol, but increased spontaneous locomotor activity, whereas the highest doses of NBQX (3 & 6 mg/kg) significantly decreased operant responding and correspondingly decreased the breaking point in responding for ethanol on a progressive ratio schedule. NBQX (but not GYKI 52466) also significantly decreased operant responding for a food reinforcer (sucrose) as well as for a sweet tasting reinforcer (saccharin). Doses of NBQX that disrupted operant performance caused a significant reduction in locomotor activity, indicating that NBQX decreased ethanol self-administration only at doses which disrupt motor activity.



These results suggest non-NMDA glutamate-receptors may not have a specific role in the maintenance of responding for an ethanol reinforcer, but may generally disrupt operant performance. Because, unlike GYKI 52466, NBQX possesses an action at central kainate receptors, these results suggest that kainate, but not AMPA (alpha-amino 3-hydroxy-5-methyl-4-isoxazole propionate) receptors may be important in mediating the reinforcing effects of ethanol.

Field of study: Medicine
Risperidone versus other atypical antipsychotic medication for schizophrenia

Risperidone is one of a number of atypical antipsychotics that are currently being marketed for the treatment of people with schizophrenia, largely on the basis of claims of improved tolerability and effectiveness compared with much cheaper conventional antipsychotics. The efficacy of risperidone has already been compared with conventional drugs, but it remains unclear how risperidone compares with other atypical antipsychotic drugs, such as clozapine.

Field of study: Medicine, Psychology
Structured Rankings of Internet Service Providers on Data and Price in Ghana

The purpose is to compare internet prices of the nation’s Internet Service Providers (ISPs) with the aim of ranking them to find out the low cost leaders in the industry. Generally the local ISPs employ the strategy of volume-tiered pricing. Volume-tiered strategies exhibit greater complexity in pricing, more opaque prices and sometimes, even higher prices. The advantage of volume-based pricing for operators is that the uncertainty and risk of consumption remains with the customer, rather than the operator. In addition the ISPs offer disparate data volumes and price points with many of them unique so as to perhaps discourage direct comparisons with one another. This paper overcame the issue of complexity, opacity and the dissimilarities in data offerings by fitting regression functions to the data of the competing ISPs and examining the behaviors of the generated graphs across a broad range. The study clearly identified the low cost leaders in the local ISP industry. Currently there is no national ranking system to find out the relative placements of the ISPs in their various service offerings. The contribution represents one of the first times internet service prices in the country have been analytically studied to identify the ISPs with the best prices. may be useful to political decision-makers and regulatory authorities. ch indicate the complexity of the audited firm and the characteristics of the audit.

Field of study: Business
Dynamic properties of complex adaptive ecosystems: implications for the sustainability of service provision

Predicting environmental change and its impacts on ecosystem goods and services at local to global scales remains a significant challenge for the international scientific community. This is due largely to the fact that the Earth is made up of open, coupled, complex, interactive and non-linear dynamic systems that are inherently unpredictable. Uncertainties over interactions and feedbacks between natural and human drivers of environmental change (operating at different spatial and temporal scales) can compound intrinsic intractable difficulties faced by plural societies aiming at sustainable management of ecosystems. Social-Ecological Systems (SES) theory addresses these strongly coupled and complex characteristics of social and ecological systems. It can provide a useful framework for articulating contrasting drivers and pressures on ecosystems and associated service provision, spanning different temporalities and provenances. Here, system vulnerabilities (defined as exposure to threats affecting ability of an SES to cope in delivering relevant functions), can arise from both endogenous and exogenous factors across multiple time-scales. Vulnerabilities may also take contrasting forms, ranging from transient shocks or disruptions, through to chronic or enduring pressures. Recognising these diverse conditions, four distinct dynamic properties emerge (resilience, stability, durability and robustness), under which it is possible to maintain system function and, hence, achieve sustainability.

Field of study: Environmental science
Mean-Field Variational Inference for Gradient Matching with Gaussian Processes

Gradient matching with Gaussian processes is a promising tool for learning parameters of ordinary differential equations (ODE's). The essence of gradient matching is to model the prior over state variables as a Gaussian process which implies that the joint distribution given the ODE's and GP kernels is also Gaussian distributed. The state-derivatives are integrated out analytically since they are modelled as latent variables. However, the state variables themselves are also latent variables because they are contaminated by noise. Previous work sampled the state variables since integrating them out is \textit{not} analytically tractable. In this paper we use mean-field approximation to establish tight variational lower bounds that decouple state variables and are therefore, in contrast to the integral over state variables, analytically tractable and even concave for a restricted family of ODE's, including nonlinear and periodic ODE's. Such variational lower bounds facilitate "hill climbing" to determine the maximum a posteriori estimate of ODE parameters. An additional advantage of our approach over sampling methods is the determination of a proxy to the intractable posterior distribution over state variables given observations and the ODE's.

Field of study: Computer science
The preimage security of double-block-length compression functions

We present new techniques for deriving preimage resistance bounds for block cipher based double-block-length, double-call hash functions. We give improved bounds on the preimage security of the three "classical" double-block-length, double-call, block cipher-based compression functions, these being Abreast-DM, Tandem-DM and Hirose's scheme. For Hirose's scheme, we show that an adversary must make at least 22n−5 block cipher queries to achieve chance 0.5 of inverting a randomly chosen point in the range. For Abreast-DM and Tandem-DM we show that at least 22n−10 queries are necessary. These bounds improve upon the previous best bounds of Ω(2n) queries, and are optimal up to a constant factor since the compression functions in question have range of size 22n.

Field of study: Computer science, Mathematics
Linear fitting of multi-threshold counting data with a pixel-array detector for spectral X-ray imaging.

Experiments and modeling are described to perform spectral fitting of multi-threshold counting measurements on a pixel-array detector. An analytical model was developed for describing the probability density function of detected voltage in X-ray photon-counting arrays, utilizing fractional photon counting to account for edge/corner effects from voltage plumes that spread across multiple pixels. Each pixel was mathematically calibrated by fitting the detected voltage distributions to the model at both 13.5 keV and 15.0 keV X-ray energies. The model and established pixel responses were then exploited to statistically recover images of X-ray intensity as a function of X-ray energy in a simulated multi-wavelength and multi-counting threshold experiment.

Field of study: Physics
Variation Diminishing Transformations: A Direct Approach to Total Positivity and its Statistical Applications

Karlin has shown that the variation diminishing property possessed by totally positive distributions allows a unified and straightforward presentation of many basic properties of hypothesis tests. His work in fact reveals that total positivity is equivalent to a suitably formulated variation diminishing property. This largely expository article begins with the latter concept and consequently gives a more direct account of the theory. This approach avoids the extensive mathematical preliminaries previously required and isolates the more important statistical property.

Field of study: Mathematics
Biological invasions in World Heritage Sites: current status and a proposed monitoring and reporting framework

UNESCO World Heritage Sites (WHS) are areas of outstanding universal value and conservation importance. They are, however, threatened by a variety of global change drivers, including biological invasions. We assessed the current status of biological invasions and their management in 241 natural and mixed WHS globally by reviewing documents collated by UNESCO and IUCN. We found that reports on the status of biological invasions in WHS were often irregular or inconsistent. Therefore, while some reports were very informative, they were hard to compare because no systematic method of reporting was followed. Our review revealed that almost 300 different invasive alien species (IAS) were considered as a threat to just over half of all WHS. Information on IAS management undertaken in WHS was available for fewer than half of the sites that listed IAS as a threat. There is clearly a need for an improved monitoring and reporting system for biological invasions in WHS and likely the same for other protected areas globally. To address this issue, we developed a new framework to guide monitoring and reporting of IAS in protected areas building on globally accepted standards for IAS assessments, and tested it on seven WHS. The framework requires the collation of information and reporting on pathways, alien species presence, impacts, and management, the estimation of future threats and management needs, assessments of knowledge and gaps, and, using all of this information allows for an overall threat score to be assigned to the protected area. This new framework should help to improve monitoring of IAS in protected areas moving forward.

Field of study: Environmental science
Organic photochromism (IUPAC Technical Report)

This technical report is a general introduction to organic photochromism. The definition of photochromism (PC) is given together with that of words with the ending "chromism", such as thermo-, electro-, piezo-, and tribochromism. Important concepts such as two-photon, gated, dual-mode PC and chirochromism are illustrated. The concept of fatigue (chemical degradation) and the determination of the main photochromic parameters (number of cycles, cyclability, half-life), and the spectrokinetic and mechanistic aspects are discussed. The main families of PC (organic compounds and biological receptors) are illustrated with chemical formulae, and the different types of reactions involved in the photochromic processes (pericyclic reactions, E/Z isomerization, group transfer, etc.) are listed. Some examples of applications to "optical power limiting" substances, photoresponsive materials, and photoswitchable biomaterials are considered.

Field of study: Chemistry
State Governors in the Mexican Revolution, 1910–1952: Portraits in Conflict, Courage, and Corruption (review)

Since the 1970s, regional studies of postrevolutionary Mexico have thrived amid scholarly interest in explaining the PRI's control of the state through much of the twentieth century. But even with the recent cultural turn, which has emphasized the local and popular facets of state building, regional studies still commonly portray governors as either charismatic caudillos or bland bureaucratic cogs in the ruling party's patronage machine. This collection, by contrast, shows us governors who were occasionally violent and sometimes heroic, though most often pragmatic. As William Beezley suggests in his introductory chapter, many governors pursued the hard-headed state building at the regional level—including mass organizing, social reform, and the modernization of infrastructure and taxation—that ultimately underpinned the consolidation of the national state. Almost all of the content chapters eschew explicit theoretical and historiographical insights, but together they make important contributions regarding state building, regional sovereignty, and the Janus-face of Revolutionary politics.

Field of study: History