nils-herrmann/clean_scirepeval huggingface dataset:
Effect of Heat Treatment in Air on Thermoelectric Properties
of Polycrystalline Type-I Silicon-Based Clathrate: Ba8Al15Si31

The effect of heat treatment in air on the thermoelectric properties was investigated for polycrystalline Ba8Al15Si31, where the Al content is almost at the maximum in the Ba8AlxSi46−x system, to evaluate the thermal stability in air at high temperatures, which is indispensable for practical use in thermoelectric applications. Samples were prepared by combining arc melting and spark plasma sintering techniques. Heat treatments were performed in air at 873 K for 10 days and 20 days. The Seebeck coefficient, electrical conductivity, and thermal conductivity were measured before and after the heat treatments. The microstructure and chemical composition were also analyzed before and after the heat treatments, using scanning electron microscopy with energy-dispersive x-ray spectroscopy. Although an oxidation layer was formed on the surface by the heat treatment in air, the chemical composition of the interior of Ba8Al15Si31 was found to be stable in air at 873 K for 10 days and 20 days. The Seebeck coefficient, the electrical conductivity, and the thermal conductivity were found to be almost unchanged after the heat treatment, indicating that Ba8Al15Si31 clathrate is promising as a thermoelectric material with high thermal stability for use in air at 873 K.

Field of study: Materials science
Density measurements of liquid under high pressure and high temperature.

A new method for density measurements by means of X-ray absorption under high pressure and high temperature using synchrotron radiation has been developed. The method has been modified for a large-volume Paris-Edinburgh press and combined with intense high-energy X-rays at the ESRF. In order to overcome effects of deformation of sample shape under pressure, a ruby cylinder was used as a sample container. The density was determined from the intensity profile of transmitted X-rays. The densities of crystalline and liquid Bi were successfully measured up to 750 K at 1 GPa.

Field of study: Physics
Modern analogs reveal the origin of Carboniferous coal balls

Coal balls are calcareous peats with cellular permineralization invaluable for understanding the anatomy of Pennsylvanian and Permian fossil plants. Two distinct kinds of coal balls are here recognized in both Holocene and Pennsylvanian calcareous Histosols. Respirogenic calcite coal balls have arrays of calcite δ18O and δ13C like those of desert soil calcic horizons reflecting isotopic composition of CO2 gas from an aerobic microbiome. Methanogenic calcite coal balls in contrast have invariant δ18O for a range of δ13C, and formed with anaerobic microbiomes in soil solutions with bicarbonate formed by methane oxidation and sugar fermentation. Respirogenic coal balls are described from Holocene peats in Eight Mile Creek South Australia, and noted from Carboniferous coals near Penistone, Yorkshire. Methanogenic coal balls are described from Carboniferous coals at Berryville (Illinois) and Steubenville (Ohio), Paleocene lignites of Sutton (Alaska), Eocene lignites of Axel Heiberg Island (Nunavut), Pleistocene peats of Konya (Turkey), and Holocene peats of Gramigne di Bando (Italy). Soils and paleosols with coal balls are neither common nor extinct, but were formed by two distinct soil microbiomes.

Field of study: Environmental science, Geography
Equilibria in structured populations

The existence of a stable positive equilibrium state for the density ρ of a population which is internally structured by means of a single scalar such as age, size, etc. is studied as a bifurcation problem. Using an inherent birth modulus n as a bifurcation parameter it is shown for very general nonlinear model equations, in which vital birth and growth processes depend on population density, that a global unbounded continuum of nontrivial equilibrium pairs (n, ρ) bifurcates from the unique (normalized) critical point (1, 0). The pairs are locally positive and conditions are given under which the continuum is globally positive. Local stability is shown to depend on the direction of bifurcation. For the important case when density dependence is a nonlinear expression involving a linear functional of density (such as total population size) it is shown how a detailed global bifurcation diagram is easily constructed in applications from the graph of a certain real valued function obtained from an invariant on the continuum. Uniqueness and nonuniqueness of positive equilibrium states are studied. The results are illustrated by several applications to models appearing in the literature.

Field of study: Biology, Mathematics
Design and implementation of a Byzantine fault tolerance framework for Web services

Many Web services are expected to run with high degree of security and dependability. To achieve this goal, it is essential to use a Web services compatible framework that tolerates not only crash faults, but Byzantine faults as well, due to the untrusted communication environment in which the Web services operate. In this paper, we describe the design and implementation of such a framework, called BFT-WS. BFT-WS is designed to operate on top of the standard SOAP messaging framework for maximum interoperability. It is implemented as a pluggable module within the Axis2 architecture, as such, it requires minimum changes to the Web applications. The core fault tolerance mechanisms used in BFT-WS are based on the well-known Castro and Liskov's BFT algorithm for optimal efficiency. Our performance measurements confirm that BFT-WS incurs only moderate runtime overhead considering the complexity of the mechanisms.

Field of study: Computer science, Engineering
The Impact of Technological Change on Market Power and Market Failure in Telecommunications

Technological change is an historical constant-no era has lacked for it. But it cannot be denied that it waxes and wanes. Its pace has quickened recently, with dramatic impacts on telecommunications, broadening its very definition. No longer is it confined to voice sent over copper wire, but now also is applied to such applications as e-mail, data, and video transmitted over fiber optics, cable, and satellite (Blumenstein 2000b, R4). Recent years have seen the development of broadband, capable of high speed delivery of large quantities of voice and data, accessed through cable or digital subscriber lines (DSLs), copper telephone wires modified to boost capacity. Wireless telephony has become a mass phenomenon; broad usage of wireless Internet is thought to be imminent. Institutional economics consistently has recognized the inevitability and ongoing nature of technological change, and its importance in shaping the future. Where neoclassical models regularly hold technology constant or bury it in residuals, institutionalists, though interpreting the term diversely (e.g., Hamilton 1986), uniformly view it as a causal force. Moreover, actual and perceived relationships among technological change, regulation, and market forces influence public policy in subtle and often poorly understood ways. Among the many grounds upon which economic regulation is faulted is its hindrance of innovation.' Deregulation is advocated as an incentive to risk taking, including investment in new technology. Moreover, technology is portrayed as destructive even of natural monopoly and as decentralizing because, for example, it produces substitutes (Friedman 1962, 28-9), eroding both monopoly on the supply side and consumer necessity on the demand side, modifying the "affected with a public interest"

Field of study: Economics
Extension of a negative multinomial model

An extension and applications of a negative multinomial model are presented. Unification of this and other models is studied. The extended model is shown to be the product of a negative multinomial distribution and a multinomial distribution such that the joint distribution has its “success” probabilities adding up to one. Among other properties, this discrete multivariate distribution provides a natural extension to the inverse sampling scheme and is also the limiting distribution of another related practical model.The maximum likelihood estimator and the UMVUE of the parameters are also determined.

Field of study: Mathematics
Low-Temperature Infrared Studies of the Chemistry of Free Radicals

The recent successful experiments involving the production and chemical reactions of simple free radicals suspended in matrices at cryogenic temperatures are reviewed. Infrared spectral observations on the radicals HCO, NH, NF, NCl, NBr, and HO2 are summarized. Reactions of H atoms and O atoms and of the isoelectronic species CH2 and NH with simple molecules suspended in a matrix are discussed, indicating some of the more promising lines of current research.

Field of study: Physics
Surrogate Demand: A Note on Demand Theory

SOME twenty years ago, I showed Abba Lerner a page of my writing that purported to be, I thought, a needed addition to demand theory. At that time, Lerner was teaching at Queens College (CUNY), my home base. He was less than enthusiastic about my contribution. Along with a legion of others, I was, and still am, awed by Lerner's analytical ability and broadbased knowledge. After all, I had assembled a Festschrift in Abba's honor and felt (as did, among others, Paul Samuelson) that Lerner should have gained a Nobel. My reluctance, therefore, to submit my idea for publication, when it had not had a positive impact on Lerner, is understandable. I shelved the page. Unfortunately, Lerner is no longer with us. However,

Field of study: Economics
Elucidating the Dark Side of Envy: Distinctive Links of Benign and Malicious Envy With Dark Personalities

Researchers have recently drawn a contrast between two forms of envy: benign and malicious envy. In three studies (total N = 3,123), we challenge the assumption that malicious envy is destructive, whereas benign envy is entirely constructive. Instead, both forms have links with the Dark Triad of personality. Benign envy is associated with Machiavellian behaviors, whereas malicious envy is associated with both Machiavellian and psychopathic behaviors. In Study 1, this pattern emerged from meta-analyzed trait correlations. In Study 2, a manipulation affecting the envy forms mediated an effect on antisocial behavioral intentions. Study 3 replicated these patterns by linking envy to specific antisocial behaviors and their impact on status in the workplace. Together, our correlational and experimental results suggest that the two forms of envy can both be malevolent. Instead of evaluating envy’s morality, we propose to focus on its functional value.

Field of study: Psychology
Effects of Sodium Hydrosulfide on the Senescence and Physiological Characteristics of Garlic

The effects of exogenous hydrogen sulfides on the senescence and physiological and biochemical characteristics of garlic leaf were studied.The results showed that the root activity and chlorophyll content of garlic leaf kept higher by different concentrations(0,100,500,1 000,1 500 μmol/L)of NaHS treatment,especially under the 500 μmol/L treatment.Hydrogen sulfides treatment significantly increased activities of SOD,POD,CAT and APX,which was conducive to scavenging reactive oxygen species of garlic leaf,and reduced the damage to cell membrane of garlic leaf.The results of the primary performance were also exhibited in lower electrolyte leakage rate,MDA content and higher free water content of garlic leaf compared with the control.So the senescence of garlic was delayed.Treatment of high concentration H2S intensified its senescence

Field of study: Agricultural and Food sciences
The Creation of the British Atlantic World (review)

transnational human rights movement. Markarian writes a fascinating study of how the Uruguayan Left and the human rights movement worked together, drawing on specific and well-researched examples. For example, she shows, in just the right amount of detail, why members of the Uruguayan Left were able to mount such a successful human rights campaign in the U.S. Congress and why they worked so well with transnational human rights organizations like Amnesty International. Her study provides new insight into the various responses the Uruguayan Left had to the dictatorship, most especially its embrace of a new understanding of human rights and individual liberty.

Field of study: History
[Epilepsy with generalized convulsive seizures on awakening (epilepsy with generalized tonic-clonic seizures "around sleep")].

: Seventy patients with idiopathic epilepsy with generalized tonic-clonic seizures (GTCS) on awakening were analyzed. In 30% of patients, seizures occurred with the same frequency or less often only on falling asleep. Two groups of patients were specified: with isolated GTCS on awakening and with a combination of the latter with myoclonia and absences. Awakening as a factor provoking seizures can be significant not only for night sleep but also for day sleep, mostly in patients with isolated GTCS. This allows to define the syndrome as an epilepsy with GTCS "around sleep". At the same time, there were 6 patients with clinical and EEG features of symptomatic epilepsy. Heterogeneity of the syndrome with GTCS "around sleep" is also related to the mental state of patients and their response to AED: carbamazepine is more effective in patients with isolated GTCS and valproate in those with the combination of GTCS with myoclonia and absences.

Field of study: Medicine, Psychology
Elucidation of the topological parameters of N-acetylneuraminic acid and some analogues involved in their interaction with the N-acetylneuraminate lyase from Clostridium perfringens.

A series of neuraminic acid derivatives modified in the side chain or at C-3, C-4 or C-5 were tested as substrates of inhibitors of N-acetylneuraminate lyase (EC 4.1.3.3) from Clostridium perfringens. The results, together with Km and Ki values reported previously, indicate that the region most important for the binding of sialic acids is an equatorial zone reaching from C-8 via the ring oxygen atom to C-4 of the sugar molecule, whereas the substituents at C-9 and C-5 may be varied to a higher extent without significantly disturbing enzyme action. It is shown that stereo-electronic factors are responsible for the immediate heterolytic fragmentation of the cyclic sialic acid into pyruvic acid and 2-acetamidomannose or a related C-6 sugar.

Field of study: Biology, Computer science
Adaptive linear filtering using interior point optimization techniques

We propose a novel approach for the linear adaptive filtering problem using techniques from interior point optimization. The main idea is to formulate a feasibility problem at each iteration and obtain as an estimate a filter near the center of the feasible region. It is shown, under some mild conditions, that this algorithm generates a sequence of filters converging to the optimum linear filter at the rate O(1/n), where n is the number of data samples. Furthermore, we show that the algorithm can be made recursive with a per-sample complexity of O(M/sup 2.3/), where M is the filter length. The potential of the algorithm for practical applications is demonstrated via numerical simulations where the new algorithm is shown to have superior transient behavior and improved robustness to the source signal statistics when compared to the recursive least squares (RLS) method.

Field of study: Engineering
Paleoenvironmental changes across the Carnian/Norian boundary in the Black Bear Ridge section, British Columbia, Canada

The Black Bear Ridge section in northeastern British Columbia, Canada, consists of a continuously exposed sequence of Upper Carnian through Lower Norian (Upper Triassic) continental margin strata. The section has been proposed as a candidate Global Stratotype Section and Point (GSSP) for the Carnian/Norian boundary (CNB). In order to assess Late Carnian to Early Norian environmental changes recorded in the section, we examined stratigraphic variations in 87Sr/86Sr, δ13C, and δ18O values, and also values of redox sensitive elements (V, Ni and Cr), in the CNB interval. The study section is located along the north shore of Williston Lake, northeastern British Columbia. The Black Bear Ridge section was deposited in a distal ramp environment on the passive western margin of the North American craton. The strata across the CNB display a positive shift in δ13C values and a corresponding increase in the redox indices V/(V + Ni) and V/Cr. The synchronous increase in δ13C values and redox indices suggests that burial rates of marine organic carbon increased in response to the development of anoxic conditions in the water column. An increase in δ13C values in carbonate rocks across the CNB has also been reported from Upper Triassic sections in the western Tethys (e.g., in the Pizzo Mondello section, Sicily), which suggests that the development of anoxic conditions within the CNB interval was widespread, affecting both the Panthalassan Ocean and Tethyan Sea. The geochemical data from this study, as well as from research into conodont biostratigraphy in the Black Bear Ridge section, show that the onset of oceanic anoxic conditions may have been responsible for the faunal turnover event at the CNB. The cause of this anoxic event is unknown, but the 87Sr/86Sr and δ13C isotope data largely exclude the possibility that the event was triggered by dissociation of methane hydrates and degassing related to large-scale volcanic activity.

Field of study: Environmental science, Geography
Standardization of Rearing Technique for Neoseiulus (=Amblyseius) longispinosus, a Predator of two Spotted Spider Mite

Vegetables, being grown in the polyhouses in Himachal Pradesh, experience heavy damage due to the attack of two spotted spider mite, Tetranychus urticae (Koch) (Acari: Tetranychidae). Neoseiulus longispinosus (Evans) (Acari: Phytoseiidae) is a potential predator of this mite, which can be successfully used to control its population. The rearing technique of predatory mite was standardized by rearing T. urticae on bean plants raised in poly pots and releasing the counted number of predators on the infested bean plants. In the summer months multiplication of predator was found to be faster than in the winter months. Total life cycle of N. longispinosus was found to range between 7 to 14 days in the winter months of November and December. The predator: prey ratio required to wipe out population of T. urticae in a week was found to be 1: 30 during July- August and 1: 17 during November-December.

Field of study: Biology
L1157-B1: WATER AND AMMONIA AS DIAGNOSTICS OF SHOCK TEMPERATURE

We investigate the origin and nature of the profiles of water and ammonia observed toward the L1157-B1 clump as part of the HIFI CHESS survey using a new code coupling a gas-grain chemical model with a parametric shock model. First results from the unbiased survey reveal different molecular components at different excitation conditions coexisting in the B1 bow shock structure, with NH3, H2CO, and CH3OH emitting only at relatively low outflow velocities whereas H2O shows bright emission at high velocities. Our model suggests that these differences are purely chemical and can be explained by the presence of a C-type shock whose maximum temperature must be close to 4000 K along the B1 clump.

Field of study: Physics
Differences in Mathematics Teachers’ Perceived Preparedness to Demonstrate Competence in Secondary School Mathematics Content by Teacher Characteristics

A sample of 300 mathematics teachers drawn from a population of 1500 participated in this study. The participants were selected using systematic random sampling and stratified random sampling (stratified by qualification and gender). The data was collected using self-report questionnaires for mathematics teachers.  One tool was used to collect data; Teachers Preparedness Questionnaire (TPQ) for mathematics. The instruments were validated by experts in the department of Curriculum, Instruction and Education Management. The instruments were pilot tested and reliability coefficient was calculated and found to be 0.83, which is above the required threshold coefficient of 0.70, Cronbach alpha in social science research. The collected data was analysed using both descriptive (means and percentages) and inferential statistics (ANOVA and t-test) to establish differences in teacher’s perceived preparedness to demonstrate competence to implement secondary school mathematics content by Teaching Experience, qualification and Gender. To establish whether there were statistically significant differences in mathematics teachers’ perceived preparedness by qualification, ANOVA was used. The hypotheses were tested at coefficient Alpha (α) level of 0.05. The test of differences show that there is a statistically significant difference in teachers’ perceived preparedness to implement secondary school mathematics content by teaching experience; however there is no statistically significant difference by teacher qualification and gender.  Mathematics Content, Teaching Experience, Qualification, Gender

Field of study: Education
Cross-cultural attitudes to help-seeking among individuals who are suicidal: new perspective for policy-makers.

World Mental Health Survey data demonstrate that a high proportion of people who are suicidal receive no treatment and that, contrary to previous assumptions, attitudes to treatment constitute greater barriers to help-seeking than do stigma or structural/financial constraints. We explore how suicide-prevention policy-makers might respond to Bruffaerts et al's findings.

Field of study: Medicine, Psychology
Calhex231 Ameliorates Cardiac Hypertrophy by Inhibiting Cellular Autophagy in Vivo and in Vitro

Intracellular calcium concentration ([Ca2+]i) homeostasis, an initial factor of cardiac hypertrophy, is regulated by the calcium-sensing receptor (CaSR) and is associated with the formation of autolysosomes. The aim of this study was to investigate the role of Calhex231, a CaSR inhibitor, on the hypertrophic response via autophagy modulation.  Cardiac hypertrophy was induced by transverse aortic constriction (TAC) in 40 male Wistar rats, while 10 rats underwent a sham operation and served as controls. Cardiac function was monitored by transthoracic echocardiography, and the hypertrophy index was calculated. Cardiac tissue was stained with hematoxylin and eosin (H&E) or Masson's trichrome reagent and examined by transmission electron microscopy. An angiotensin II (Ang II)-induced cardiomyocyte hypertrophy model was established and used to test the involvement of active molecules. Intracellular calcium concentration ([Ca2+]i) was determined by the introduction of Fluo-4/AM dye followed by confocal microscopy. The expression of various active proteins was analyzed by western blot.  The rats with TAC-induced hypertrophy had an increased heart size, ratio of heart weight to body weight, myocardial fibrosis, and CaSR and autophagy levels, which were suppressed by Calhex231. Experimental results using Ang II-induced hypertrophic cardiomyocytes confirmed that Calhex231 suppressed CaSR expression and downregulated autophagy by inhibiting the Ca2+/calmodulin-dependent-protein kinase-kinase-β (CaMKKβ)- AMP-activated protein kinase (AMPK)-mammalian target of rapamycin (mTOR) pathway to ameliorate cardiomyocyte hypertrophy.  Calhex231 ameliorates myocardial hypertrophy induced by pressure-overload or Ang II via inhibiting CaSR expression and autophagy. Our results may support the notion that Calhex231 can become a new therapeutic agent for the treatment of cardiac hypertrophy.

Field of study: Biology, Chemistry