nils-herrmann/clean_scirepeval huggingface dataset:
Covariance matrix estimation using repeated measurements when data are incomplete

Modeling repeated measurements data has been studied extensively lately in the parametric situation. However, it is significant to study the effect of various treatments over a period of time where the repeated measurements on the same subject are expected to be correlated. The correlation among the repeated measurements for all the subjects will be studied via the covariance matrix. The positive definite constraint is one of obstacles that encounters modeling the covariance structure, however the Cholesky decomposition removes this constraint and allows modeling the components of the covariance matrix [M. Pourahmadi, Joint mean-covariance models with applications to longitudinal data: unconstrained parameterization, Biometrika 86 (1999) 677-690]. In this paper, we adopt the estimation procedures introduced by Diggle and Verbyla [Nonparametric estimation of covariance structure in longitudinal data, Biometrics 54 (1998) 401-415] where the variogram cloud as well as the squared residuals are used to estimate the variogram and the variances via the kernel smoothing. Selecting the appropriate bandwidth value is one of the important steps in the estimation process, thus in our data analysis we choose the bandwidth using one of the most simple straight forward methods which is the cross-validation method developed by Rice and Silverman [Estimating the mean and covariance structure nonparametrically when the data are curves,  (1991) 233-243] and adapted by others. Finally we apply these nonparametric techniques as well as a graphical method [M. Pourahmadi, Joint mean-covariance models with applications to longitudinal data: unconstrained parameterization, Biometrika 86 (1999) 677-690] to a real life data and use the penalized likelihood criterion like AIC and BIC to compare models of our interest. our interest.

Field of study: Mathematics
Ma deuxième revue médicale favorite

> Apres-midi d’ete—apres-midi d’ete; c’est la pour moi la plus belle expression du vocabulaire. 
> 
> Henry James (traduction libre)![Figure][1] 

Meme si nous vivons a l’ere de l’Internet, la plupart des lecteurs du Medecin de famille canadien preferent recevoir la

Field of study: Medicine
Role of natural fibres: Rubber/polyester composites reinforced with sansevieria cylindrica, waste silk, jute and drumstickvegetable fibres (Moringa oleifera)

Despite thermoset polymers have been widely used as engineering components, adhesives and matrix fibre reinforced composites due to their versatile mechanical properties compared to those of thermoplastics polymer, they virtually brittle and vulnerable to crack.Addition of ductile materials such as rubber microsized natural fibres are added in these polymers would help in gaining tensile and flexural strength, corrosion resistance, toughness and water absorption properties. Aim of this work is to investigate the tensile, flexural and dielectric properties of compositesmade by reinforcing Sansevieria cylindrica as a newnatural fibre into a rubber based polyestermatrix. The fibres were extracted by retting and manual processes have been used to fabricate the composites. These composites were tested for the properties which mentioned above and compared with those of established composites like waste silk, drumstick vegetable fiber and jute made under the ASTM conditions. The compositeswere fabricated up to amaximumvolume fraction of fibre of 0.35 for impact testing, tensile, flexural and dielectric testing. Itwas observed that the tensile properties were increased with respect to volume fraction of fibre for Sansevieria cylindrica fibre composite and are also more than those of silk and drumstick composites and comparable to those of jute composites. The flexural strength of Sansevieria cylindrica fibre composite is more than that of waste silk composite and is closer to drumstick fibre compositewith respect to the volume fraction of fibre,where as the flexuralmodulus is much higher than those of jute, drumstick vegetable fibre composites and also very much closer to silk fibre composites. The dielectric strength of Sansevieria cylindrica fibre composite was increasedwith increase in volume fraction of fibre in the composite unlike the case ofwaste silk, jute and drumstick tree vegetable fibre composites. The dielectric strength being a unique feature of Sansevieria cylindrica fibre composite can be suggested for electrical insulation applications.

Field of study: Materials science
Dilemmatic conversations: Some challenges of culturally responsive discourse in a high school English classroom

This paper reports findings derived from a qualitative research study focused on seven English teachers at a hyperdiverse high school as they learned to analyze their classroom talk for moments of conflict. Using methods derived from interactional ethnography and systemic functional linguistics, the author analyzes the ways that one teacher uses a “heroic White teacher” text, LouAnne Johnson's autobiographical novel Dangerous Minds , to talk about the societal significance of “the n -word” with her students, attempting to navigating ideological dilemmas of race and difference in her discourse. The study ends by calling for further description, analysis, and careful consideration of the culturally responsive discourse and interaction of teachers from all backgrounds, which can be useful for helping researchers, teacher educators, and policymakers understand how identities and social subjectivities are negotiated in and through talk and action.

Field of study: Education, Linguistics
Construction and Research for Soil Remediation Industry Funding Framework of China

Soil Remediation funding of the lack of effective protection in China. For analyzed and build our soil remediation industry funding framework, drew on American Super Fund System, financial management of British"brown land"policy, according to the analysis of soil remediation of industrial capital in China follow the principles, financing mechanism, operation mode and management scope, it is constructed a financial framework of soil remediation industry status for Chinese develop-ment. Financial supported to promote the sustainable development of Soil remediation industry of China.

Field of study: Environmental science
Politics, Parties, and Elections in Argentina’s Province of Buenos Aires, 1912-42

HROUGHOUT Argentina's modern history the province of Buenos Aires has held the key to political control of the nation. In the twentieth century, and particularly after electoral reform in 1912, any party that hoped to capture the republic's presidency and dominate the national Congress viewed electoral victories in Buenos Aires as vital to success. The reasons are easy to discern; Argentina's largest, wealthiest, and most populous state, Buenos Aires has provided between 25 and 35 percent of all the republic's voters and a like proportion of presidential electors and national congressmen. Control of Buenos Aires, then, along with support in a few other districts, has virtually assured the presidential election of those candidates whose party held sway there. In only one instance in the twentieth century (1916) has an Argentine captured the nation's presidency without also capturing Buenos Aires. In 1946 Juan Per6n won the Argentine presidency, carrying the province of Buenos Aires by a comfortable margin and doing especially well in the working-class suburbs that surround the city of Buenos Aires.' After 1946 the province remained one of the major Peronist strongholds. The election of 1946 has been the object of considerable scholarly analysis

Field of study: History
Analysis of TPA Pulsed-Laser-Induced Single-Event Latchup Sensitive-Area

Two-photon absorption (TPA) pulsed-laser testing is used to analyze the TPA-induced single-event latchup sensitive-area of a specially designed test structure. This method takes into account the existence of an onset region in which the probability of triggering latchup transits between 0 and 1 as the laser pulse energy increases. This variability is attributed to a combination of laser pulse-to-pulse variability and variations in local carrier density and temperature. For each spatial position, the latchup probability associated with a given energy is calculated. Calculation of latchup cross section at lower laser energies, relative to onset, is improved significantly by taking into account the full probability distribution. The transition from low probability of latchup to high probability is more abrupt near the source contacts than for surrounding areas.

Field of study: Physics
The application of HPLC ESI MS in the investigation of the flavonoids and flavonoid glycosides of a Caribbean Lamiaceae plant with potential for bioaccumulation

As part of an exchange technology program between the government of Barbados and Environment Canada, methanolic and aqueous extracts from the flavonoid-rich Lamiaceae family were characterized using negative-ion electrospray mass spectrometry. The species investigated is part of the Caribbean Pharmacopoeia, and is used for a variety of health issues, including colds, flu, diabetes, and hypertension. The extracts were investigated for structural elucidation of phenolics, identification of chemical taxonomic profile, and evidence of bio-accumulator potential. The methanolic and aqueous leaf extracts of Plectranthus amboinicus yielded rosmarinic acid, ladanein, cirsimaritin, and other methoxylated flavonoids. This genus also shows a tendency to form conjugates with monosaccharides, including glucose, galactose, and rhamnose. The aqueous extract yielded four isomeric rhamnosides. The formation of conjugates by Plectranthus amboinicus is thus evidence of high bioaccumulator significance.

Field of study: Agricultural and Food sciences
Stochastic Simulation of Isotopic Exchange Mechanisms for Fe(II)-Catalyzed Recrystallization of Goethite.

Understanding Fe(II)-catalyzed transformations of Fe(III)-(oxyhydr)oxides is critical for correctly interpreting stable isotopic distributions and for predicting the fate of metal ions in the environment. Recent Fe isotopic tracer experiments have shown that goethite undergoes rapid recrystallization without phase change when exposed to aqueous Fe(II). The proposed explanation is oxidation of sorbed Fe(II) and reductive Fe(II) release coupled 1:1 by electron conduction through crystallites. Given the availability of two tracer exchange data sets that explore pH and particle size effects (e.g., Handler et al.  2014 , 48 , 11302 - 11311 ; Joshi and Gorski  2016 , 50 , 7315 - 7324 ), we developed a stochastic simulation that exactly mimics these experiments, while imposing the 1:1 constraint. We find that all data can be represented by this model, and unifying mechanistic information emerges. At pH 7.5 a rapid initial exchange is followed by slower exchange, consistent with mixed surface- and diffusion-limited kinetics arising from prominent particle aggregation. At pH 5.0 where aggregation and net Fe(II) sorption are minimal, that exchange is quantitatively proportional to available particle surface area and the density of sorbed Fe(II) is more readily evident. Our analysis reveals a fundamental atom exchange rate of ∼10-5 Fe nm-2 s-1, commensurate with some of the reported reductive dissolution rates of goethite, suggesting Fe(II) release is the rate-limiting step in the conduction mechanism during recrystallization.

Field of study: Environmental science
The Dipper-Du Conjecture Revisited

We consider vertices, a notion originating in local representation theory of finite groups, for the category $\mathcal{O}$ of a rational Cherednik algebra and prove the analogue of the Dipper-Du Conjecture for Hecke algebras of symmetric groups in that setting. As a corollary we obtain a new proof of the Dipper-Du Conjecture over $\mathbb{C}$.

Field of study: Mathematics
An information-hiding metric

The most critical problem facing developers and maintainers of large software systems is overwhelming complexity. Abstraction, a powerful tool for dealing with complexity, limits details that must be considered to those that are most relevant. Programming languages have evolved to provide a high-level construct, called a module or a class, that supports abstraction by allowing the encapsulation of details and enforcing information hiding. Programs written in these modular programming languages should be designed to produce programs that are easier to understand, modify, and test. This article describes the creation of metrics for information hiding at the module level. The relationship between the information-hiding metrics and the maintainability of programs is examined by use of subjective validation and a case study of a large Ada program.

Field of study: Computer science, Engineering
Magnetization Losses of Roebel Cable Samples With 2G YBCO Coated Conductor Strands

Roebel cable with second-generation YBCO strands is one of the promising high-temperature superconducting solutions of fully transposed high current conductors for high field accelerator magnets. Following the considerable research effort on the manufacturing of Roebel cables in recent years, sample conductors are now available in useful lengths with reproducible performances to allow for detailed characterizations beyond the standard critical current measurements. The ac loss and strands coupling are of significant interest for the field quality of the accelerator magnets. We report a set of systematic ac loss measurements on two different Roebel cable samples prepared for the EuCARD-2 collaboration. The measurements were performed over a wide range of temperature values between 5 and 90 K, and the results were analyzed in the context of strands architecture and coupling. The results show that the transposed bundles are partially decoupled, and the strands in transposition sections behave as an isolated single tape if the strands are insulated.

Field of study: Physics
Multiple bonds between lead atoms and short bonds between transition metals

The heaviest analogues of alkynes are investigated to realize a short triple bond between Pb atoms. For a short double bond between Pb atoms, the Pb2 molecule stabilized by dative N-heterocyclic carbenes is investigated. For unsupported and supported short bonds between transition metals, two-coordinate transition-metal and bicyclic four-membered ring complexes are investigated.

Field of study: Chemistry
Emissions and Emergence: a new index comparing relative contributions to climate change with relative climatic consequences

We develop a new index which maps relative climate change contributions to relative emergent impacts of climate change. The index compares cumulative emissions data with patterns of signal-to-noise ratios (S/N) in regional temperature (Frame et al., 2017). The latter act as a proxy for a range of local climate impacts, so emergent patterns of this ratio provide an informative way of summarising the regional disparities of climate change impacts. Here we combine these with measures of regional/national contributions to climate change to develop an "emissions-emergence index" (EEI) linking regions'/countries' contributions to climate change with the emergent regional impacts of climate change. The EEI is a simple but robust indicator which captures relative contributions to and regional impacts from climate change. We demonstrate the applicability of the EEI both for discussions of historical contributions and impacts, and for considering future relative contributions and impacts, and examine its utility in the context of existing related metrics. Finally, we show how future emissions pathways can either imply a growth or reduction of regional climate change inequalities depending on the type and compositions of socioeconomic development strategies.

Field of study: Environmental science
Effect of heat treatment on structure and properties of MgO-PSZ electrolyte

The properties of MgO partially stabilized zirconia (MgO-PSZ) can be greatly improved by heat treatment. In this work the effects of heat treatment on the electrical conductivity and thermal shock resistance of MgO-PSZ were investigated. The changes of microstructure of MgO-PSZ treated with different temperature profiles were studied by using transmission electron microscopy. It was found by dilatometric technique that the phase transformation from monoclinic to tetragonal takes place at two temperature ranges. For large monoclinic grains the phase transformation temperature is around 1170°C. However, for small monoclinic grains, generated by heat treatment, the transformation occurs in the temperature range 550–800°C. The thermal shock resistance can be greatly improved by means of ageing at 1400°C for two hours or at 1100°C for six hours.

Field of study: Materials science
Lower rim 1,3-disubstituted derivatives of calix[4]arene amides having amino acid ester and amines as pendants

Lower rim modification of calix[4]arene at its 1,3-alternate positions to result in the molecules of potential importance possessing amide bonds and other functional moieties as generated from the reaction between calix[4]arene-1,3-diacid and the amino acids and/or substituted amines was carried out and the structural properties of the products were addressed.

Field of study: Chemistry
A new non parametric estimator for Pdf based on inverse gamma distribution

The non parametric approach is considered to estimate probability density function (Pdf) which is supported on(0, ∞). This approach is the inverse gamma kernel. We show that it has same properties as gamma, reciprocal inverse Gaussian, and inverse Gaussian kernels such that it is free of the boundary bias, non negative, and it achieves the optimal rate of convergence for the mean integrated squared error. Also some properties of the estimator were established such as bias and variance. Comparison of the bandwidth selection methods for inverse gamma kernel estimation of Pdf is done.

Field of study: Mathematics
Differential responses of plasma membrane aquaporins in mediating water transport of cucumber seedlings under osmotic and salt stresses.

It has long been recognized that inhibition of plant water transport by either osmotic stress or salinity is mediated by aquaporins (AQPs), but the function and regulation of AQPs are highly variable among distinct isoforms and across different species. In this study, cucumber seedlings were subjected to polyethylene glycol (PEG) or NaCl stress for duration of 2 h or 24 h. The 2 h treatment with PEG or NaCl had non-significant effect on the expression of plasma membrane AQP (CsPIPs) in roots, indicating the decrease in hydraulic conductivity of roots (Lpr ) and root cells (Lprc ) measured in these conditions were due to changes in AQP activity. After both 2 h and 24 h PEG or NaCl exposure, the decrease in hydraulic conductivity of leaves (Kleaf ) and leaf cells (Lplc ) could be attributed to a down-regulation of the two most highly expressed isoforms, CsPIP1;2 and CsPIP2;4. In roots, both Lpr and Lprc were further reduced after 24 h PEG exposure, but partially recovered after 24 h NaCl treatment, which were consistent with changes in the expression of CsPIP genes. Overall, the results demonstrated differential responses of CsPIPs in mediating water transport of cucumber seedlings, and the regulatory mechanisms differed according to applied stresses, stress durations and specific organs.

Field of study: Environmental science
Roetevergaderings hou ons ingelig : fokus op die MPO Wes-Kaap

Die Melkprodusente-organisasie (MPO) Wes-Kaap se roetevergaderings is vanjaar gedurende Maart aangebied en was propvol nuttige inligting vir melkboere in hierdie belangrike melkproduksiestreek.

Field of study: Agricultural and Food sciences
Ready for climate change? Geographic trends in the protection status of critical sites for Western Palearctic ducks

The geographic range of many migratory bird populations is shifting in response to climate change. Protected areas play a major role in the conservation of many such species, yet these reserves are static so a geographic mismatch between the habitat needs of the birds and the network of protected areas may gradually appear. Ducks in the Western Palearctic are most likely to shift their distribution northwards and eastwards in response to climate change, so we evaluated whether the mean protection level of the most critical sites for ducks shows any latitudinal or longitudinal trend. From the description of site protection level in the Critical Site Network database (little/none to full protection) a site protection score was computed, ranging from 0 (little/none) to 3 (full protection). More northern sites had greater mean protection scores. Conversely, a negative longitudinal gradient was identified, with much poorer protection of critical duck sites in Eastern Europe, the Middle East and Central Asia. This is where duck populations are currently the largest, and among the areas where duck populations are expected to increase in the future following climate change, although currently a relatively high proportion also show decreasing population trends. The site protection score was also greatest, on average, in member states of the European Union rather than in other European countries, suggesting EU directives have been successful at improving the level of protection of the most important wetlands for ducks. Although ducks could benefit from further conservation of the sites they use anywhere within their geographic range, and there is room for improvement of protection score in all areas, this study suggests that future site protection efforts should be internationally coordinated, and first targeted at sites east of the Mediterranean shore.

Field of study: Environmental science
Differential effects of glycosphingolipids on the detergent-insolubility of the glycosylphosphatidylinositol-anchored membrane dipeptidase.

The insolubility of glycosylphosphatidylinositol (GPI)-anchored proteins in certain detergents appears to be an intrinsic property of their association with sphingolipids and cholesterol in lipid rafts. We show that the GPI-anchored protein membrane dipeptidase is localized in detergent-insoluble lipid rafts isolated from porcine kidney microvillar membranes, and that these rafts, which lack caveolin, are enriched not only in sphingomyelin and cholesterol, but also in the glycosphingolipid lactosylceramide (LacCer). Dipeptidase purified from porcine kidney was reconstituted into artificial liposomes in order to investigate the relationship between glycosphingolipids and GPI-anchored protein detergent-insolubility. Dipeptidase was insoluble in liposomes containing extremely low concentrations of LacCer. In contrast, identical concentrations of glucosylceramide or galactosylceramide failed to promote significant detergent-insolubility. Cholesterol was shown to enhance the detergent-insoluble effect of LacCer. GC-MS analysis revealed dramatic differences between the fatty acyl compositions of LacCer and those of the other glycosphingolipids. However, despite these differences, we show that the unusually marked effect of LacCer to promote the detergent-insolubility of dipeptidase cannot be singularly attributed to the fatty acyl composition of this glycosphingolipid molecule. Instead, we suggest that the ability of LacCer to confer detergent-insolubility on this GPI-anchored protein is dependent on the structure of the lipid molecule in its entirety, and that this glycosphingolipid may have an important role to play in the stabilization of lipid rafts, particularly the caveolin-free glycosphingolipid signalling domains.

Field of study: Biology, Computer science