nils-herrmann/clean_scirepeval huggingface dataset:
Estimating and Using Propensity Scores with Partially Missing Data

Investigators in observational studies have no control over treatment assignment. As a result, large differences can exist between the treatment and control groups on observed covariates, which can lead to badly biased estimates of treatment effects. Propensity score methods are an increasingly popular method for balancing the distribution of the covariates in the two groups to reduce this bias; for example, using matching or subclassification, sometimes in combination with model-based adjustment. To estimate propensity scores, which are the conditional probabilities of being treated given a vector of observed covariates, we must model the distribution of the treatment indicator given these observed covariates. Much work has been done in the case where covariates are fully observed. We address the problem of calculating propensity scores when covariates can have missing values. In such cases, which commonly arise in practice, the pattern of missing covariates can be prognostically important, and then propensity scores should condition both on observed values of covariates and on the observed missing-data indicators. Using the resulting generalized propensity scores to adjust for the observed background differences between treatment and control groups leads, in expectation, to balanced distributions of observed covariates in the treatment and control groups, as well as balanced distributions of patterns of missing data. The methods are illustrated using the generalized propensity scores to create matched samples in a study of the effects of postterm pregnancy.

Field of study: Mathematics
Are salmon's ‘guises’ disguised fregean senses?

N a review of Frege's Puzzle 1 , Graeme Forbes makes the claim that Salmon's account of belief might be seen, under certain conditions, as a mere notational variant of a neoFregean theory; and thus that such an account might be reduced to a neo-Fregean one simply by rewriting it in terms of Fregean terminology. With a view to supporting his claim, Forbes offers an outline of an account of belief which, according to him, would satisfy the following conditions: (i) it could be directly obtained from Salmon's own analysis by means of a certain set of substitutions, which presumably would not affect the essential features of Salmon's view; (ii) it could naturally be described as Fregean, in the sense that it would preserve, (at least) the spirit of Frege's doctrines, especially his fundamental intuitions about belief. Of course, the upshot of Forbes's argument is that Salmon's theory would not, at bottom, constitute a genuine alternative to a Fregean semantics for belief ascriptions. I In this paper I shall argue to the effect that Forbes's claim is not in general sound. It seems to me that the sort of indirect argument used by Forbes - that of trying to undermine Salmon's theory by showing that it is just a version of a neo-Fregean account - does not provide someone working within a Fregean framework with an adequate strategy to counter Salmon's neo-Russellian views. It would perhaps be better to concentrate a Fregean attack on certain apparently dubious and highly controversial theses and results which are constitutive of Salmon's view, e.g. the counterintuitive character of a substantial set of consequences which follow from his theory of belief, as well as the associated revisionist stand he is forced to take towards our current patterns of speaking about belief. Forbes is surely right when he says that Salmon's account implies the possibility of ascribing inconsistent beliefs to some agent. Suppose that our believer, on the basis of his visual encounters with Venus at dawn, thinks that Phosphorus is a star, and that, on the basis of his encounters with Venus at dusk, he thinks that Hesperus is not a star, but a planet. Let us represent Salmon's account by the formula (S) A believes that p iff (Ex)[A grasps p by means of x & BEL(A, p, x)]

Field of study: Philosophy
Spontaneous encephaloceles of the temporal lobe.

Encephaloceles are pathological herniations of brain parenchyma through congenital or acquired osseus-dural defects of the skull base or cranial vault. Although encephaloceles are known as rare conditions, several surgical reports and clinical series focusing on spontaneous encephaloceles of the temporal lobe may be found in the otological, maxillofacial, radiological, and neurosurgical literature. A variety of symptoms such as occult or symptomatic CSF fistulas, recurrent meningitis, middle ear effusions or infections, conductive hearing loss, and medically intractable epilepsy have been described in patients harboring spontaneous encephaloceles of middle cranial fossa origin. Both open procedures and endoscopic techniques have been advocated for the treatment of such conditions. The authors discuss the pathogenesis, diagnostic assessment, and therapeutic management of spontaneous temporal lobe encephaloceles. Although diagnosis and treatment may differ on a case-by-case basis, review of the available literature suggests that spontaneous encephaloceles of middle cranial fossa origin are a more common pathology than previously believed. In particular, spontaneous cases of posteroinferior encephaloceles involving the tegmen tympani and the middle ear have been very well described in the medical literature.

Field of study: Medicine
Significance of ring porosity in analysis of a Sangamon flora

Trees with ring-porous wood are limited to the higher latitudes and form an important component of the vegetation of North America. Analysis of the occurrence of trees with this wood type in North America east of the Rockies shows that they make up an increasing percentage of the upland tree flora as precipitation decreases. The northern limit of ring-porous trees is probably related to winter temperature extremes and a mechanism of avoiding frost damage based on supercooling of cellular water. Percent of ring-porous species has the potential for use in the reconstruction of paleoclimates. As an example, the calculated value for the Toronto Don Beds flora, which dates from the last (Sangamon) interglacial period, is only slightly greater than that of the present-day flora and thus suggests that the interglacial climate in this region was much the same or only somewhat different from today's. The differences were probably related to lower winter temperatures or lower frequency of winter temperature extremes. The climatic requirements of zonal vegetation and individual species indicate that summer temperatures were not higher than at present. The extralocal species must be evaluated carefully since nonclimatic considerations may be important in explaining their presence.

Field of study: Environmental science, Geography
Lactam acetals and acid amides. 31. Synthesis, protonation, and basicities of some heterocyclic enamino ketones

The protonation of cyclic enamino ketones of the pyrrolidine, piperidine, and hexahydroazepine series, as well as their noncyclic analogs, was studied by PMR spectroscopy. It is shown that the presence of a CH2 or CH3 group in the “enamine” position leads to C protonation (in CF3COOH). In the case of enamino ketones that do not contain substituents in the “enamine” α position N-and O-protonated forms are observed in CF3COOH. The measured pKa values (in 10% alcohol) and the ΔpKa values (in nitromethane) of the enamino ketones show that the compounds for which C protonation is characteristic are two to three orders of magnitude more basic than in the case of compounds that do not contain substituents in the “enamine” α position; this is explained by the different character of protonation.

Field of study: Chemistry
P, As, Sb, Mo, and other elements in sedimentary Fe/Mn layers of Lake Baikal.

Distinct layers with accumulated iron and manganese oxyhydroxides are found in the recent sediments of Lake Baikal (Siberia). In the South and Central Basins, these concretions accumulate close to the sediment-water interface. In northern Lake Baikal and the area of Academician Ridge, however, massive Fe/Mn crusts are formed within several thousand years at redox fronts 10 to 15 cm below the sediment surface. In some places, precipitated iron and manganese oxyhydroxides are spatially separated. The patterns are a result of secondary iron and manganese oxide precipitation. This natural long-term experiment allows the analysis of competitive adsorption and coprecipitation of trace elements with iron and manganese oxides in sediments. Background concentrations in the sediment of oxoanions (P, As, Sb, Mo); of trace metals (Cr, V, Cu, Zn, Cd, Pb); and of Mg, Ca, Sr, La, Ce, Pr, Nd, and Sm were analyzed by inductively coupled plasma mass spectrometry. Despite the differences in catchment geology of the many tributaries, they are remarkably uniform in sediment cores from different basins of Lake Baikal. Enrichment factors of P and As within Fe crusts revealed concentrations up to 14 and 58 times higher than the background, respectively. No enrichment of P and As was found in the Mn layers. By contrast, Mo accumulated exclusively in the Mn layer with up to 35-fold enrichment. Sb was only slightly enriched in both the Fe and the Mn layers. Among the trace metals studied, only Cd was found at elevated concentrations with a preference for the Mn layer. Ca and Sr were correlated with both Fe and Mn accumulations. The study quantifies the well-known specific adsorption and coprecipitation of P and As at authigenic iron oxides and of Mo on manganese oxides. In addition, the enrichment of Cd at manganese oxides in contrast to the conservative behavior of Zn and Pb reveals highly selective accumulation processes.

Field of study: Environmental science
On the non-unitarity of the Bogoliubov transformation due to the quasiparticle space truncation

We show that due to the energy cutoff in the Hartree-Fock-Bogoliubov quasiparticle space, the Bogoliubov transformation becomes non-unitary. We propose a method of restoring the unitarity by introducing a truncated single-particle Hilbert space, in which the HFB equations are to be solved.

Field of study: Physics
Militão and The Guerreiros: Local Feuds, Long Memories, and Brazil's Struggle to Control the São Francisco River

Between 1842 and 1848, a violent conflict erupted on the banks of the São Francisco River in nordieastern Brazil. Militão Plácido de França Antunes and his faction declared war on the family of Captain Bernardo José Guerreiro. Both families were based in the river town of Pilão Arcado, but the fighting spread to the nearby town of Sento-Sé, and by 1848 violence had engulfed the entire region from Barra to Juazeiro (see Figures 1 and 2). Bands of armed men loyal to Militão roamed the streets and attacked the households of people they considered to be on the side of the Guerreiros. Many people were killed, and others fled the region altogether. The violence ended only after Militão's faction killed Guerreiro's last adult son on August 1, 1848. Although a family feud in the backlands was not unusual, this fight resonated with coastal lawmakers who, in Brazil's Second Empire, had been looking toward conquering the west and consolidating their own vast territory. The reports of wrenching violence in the backlands, unchecked by the rule of law, represented the deepest fears of the coastal elite and made the need to conquer the Brazilian interior even more urgent.

Field of study: History
Analysis of functional groups in atmospheric aerosols by infrared spectroscopy: sparse methods for statistical selection of relevant absorption bands

Various vibrational modes present in molecular mixtures of laboratory and atmospheric aerosols give rise to complex Fourier transform infrared (FT-IR) absorption spectra. Such spectra can be chemically informative, but they often require sophisticated algorithms for quantitative characterization of aerosol composition. Naive statistical calibration models developed for quantification employ the full suite of wavenumbers available from a set of spectra, leading to loss of mechanistic interpretation between chemical composition and the resulting changes in absorption patterns that underpin their predictive capability. Using sparse representations of the same set of spectra, alternative calibration models can be built in which only a select group of absorption bands are used to make quantitative prediction of various aerosol properties. Such models are desirable as they allow us to relate predicted properties to their underlying molecular structure. In this work, we present an evaluation of four algorithms for achieving sparsity in FT-IR spectroscopy calibration models. Sparse calibration models exclude unnecessary wavenumbers from infrared spectra during the model building process, permitting identification and evaluation of the most relevant vibrational modes of molecules in complex aerosol mixtures required to make quantitative predictions of various measures of aerosol composition. We study two types of models: one which predicts alcohol COH, carboxylic COH, alkane CH, and carbonyl CO functional group (FG) abundances in ambient samples based on laboratory calibration standards and another which predicts thermal optical reflectance (TOR) organic carbon (OC) and elemental carbon (EC) mass in new ambient samples by direct calibration of infrared spectra to a set of ambient samples reserved for calibration. We describe the development and selection of each calibration model and evaluate the effect of sparsity on prediction performance. Finally, we ascribe interpretation to absorption bands used in quantitative prediction of FGs and TOR OC and EC concentrations.

Field of study: Environmental science
On the Origin of Ultramafic Rocks

It is argued that most alpine ultramafic bodies originated as cumulates in basic magma chambers high in the crust. From some of these chambers, magmas were intruded upward or extruded, leaving sill-like ultramafites behind. These were subsequently folded or dismembered by faulting, and, because of their high density, subsided during tectonism, to form cold, fault-enclosed intrusions. In other places, tectonism interrupted crystallization of the magmas, magma chambers were deformed, loose cumulates and hot coherent cumulate rocks slumped and slid, and hot masses, as crystal mushes and hot lenses, worked down fault zones. These hot masses were subject to high temperature recrystallization and metasomatism, as water from adjacent rocks permeated them, forming veins of pyroxenite and dunite, and intercumulus plagioclase was destroyed. Contact aureoles were formed, but some were abandoned as the cooling ultramafites descended. The Bay of Islands complex and the Great Dyke are considered to be examples of bodies whose origins as stratiform differentiates is clear but which show some of the features of alpine ultramafic masses. It is argued that Franciscan peridotites are differentiates that have been folded or have descended along faults during tectonism. It is hypothesized that ultramafites of British Columbia are complementary to late Paleozoic or Triassic volcanic rocks. Zoned ultramafic complexes of Alaska, British Columbia, and the Urals, currently believed by many to have formed by crystallization of ultramafic magmas, are re-examined. It is concluded that the central peridotites of these consist of cumulates from basic magmas and have been dropped as crude cylinders along ring fractures or are downward intrusions of ultramafic crystal mushes. Their zoning is due to subsequent metasomatism by hydrous fluids that were guided by marginal fractures. Pipes of the Bushveld Complex may have formed entirely by replacement along and adjacent to “gas chimneys.”

Field of study: Geology
Muscarinic acetylcholine receptor stimulation induces expression of the activity-regulated cytoskeleton-associated gene (ARC).

Muscarinic acetylcholine receptors (mAChR) are involved in learning and memory but their molecular function in these processes is not fully understood. In this study, the signal transduction pathway coupling mAChR activation to induction of the activity-regulated cytoskeleton-associated gene (ARC) was examined. ARC was first identified as an effector immediate early gene induced by neuronal activity and ARC protein is thought to play a role in synaptic plasticity. In rats, intraperitoneal injection of pilocarpine, a potent agonist of mAChR, led to increased ARC expression in the brain. In human SH-SY5Y neuroblastoma cells mAChR stimulation with carbachol caused a rapid and robust induction of ARC expression. This effect was inhibited by atropine, a nonselective muscarinic receptor antagonist as well as by M1/M3 subtype-specific antagonists. Analysis of mAChR downstream effectors revealed that protein kinase C (PKC) and tyrosine kinases of the src family are key molecules in the signal cascade leading to ARC expression. Our data suggest, for the first time, that a correlation exists among mAChR-controlled signal cascades, the induction of the effector immediate early gene ARC and synaptic plasticity.

Field of study: Biology
THE EFFECT OF SELECTIVE DESORPTION MECHANISMS DURING INTERSTELLAR ICE FORMATION

Major components of ices on interstellar grains in molecular clouds - water and carbon oxides - occur at various optical depths. This implies that selective desorption mechanisms are at work. An astrochemical model of a contracting low-mass molecular cloud core is presented. Ice was treated as consisting of the surface and three subsurface layers (sublayers). Photodesorption, reactive desorption, and indirect reactive desorption were investigated. The latter manifests itself through desorption from H+H reaction on grains. Desorption of shallow subsurface species was included. Modeling results suggest the existence of a "photon-dominated ice" during the early phases of core contraction. Subsurface ice is chemically processed by interstellar photons, which produces complex organic molecules. Desorption from the subsurface layer results in high COM gas-phase abundances at Av = 2.4...10mag. This may contribute towards an explanation for COM observations in dark cores. It was found that photodesorption mostly governs the onset of ice accumulation onto grains. Reaction-specific reactive desorption is efficient for small molecules that form via highly exothermic atom-addition reactions. Higher reactive desorption efficiency results in lower gas-phase abundances of COMs. Indirect reactive desorption allows to closely reproduce the observed H2O:CO:CO2 ratio towards a number of background stars. Presumably this can be done by any mechanism whose efficiency fits with the sequence CO > CO2 >> H2O. After the freeze-out has ended, the three sublayers represent chemically distinct parts of the mantle. 8...10.5mag is the likely AV threshold for the appearance of CO ice. The lower value is supported by observations.

Field of study: Physics
Data Deduplication: A technique for efficient storage in cloud

Cloud Computing allows users to outsource storage and computation to servers using internet. In this paper we propose a data Deduplication technique to reduce the amount of storage space and to save bandwidth. The convergent encryption technique has been proposed to protect the confidentiality of sensitive data. Our scheme has the feature of access which allows only valid users to share the data over the cloud storage. Data Deduplication is not only an efficient means of storage over the cloud but also enforces security over the stored data. We ensure that the authorized duplicate check scheme does not create any overhead. The hybrid cloud approach is used for data storage which is very different from the traditional systems.

Field of study: Engineering
Design of a competition training grogram that simulates real scenarios of mental capacity of Ping Pong players

Through an experiment and an example,the author gave the players directive guidance from the perspec-tive of general mental training theory,intentionally influence them,so that their mental state changes,then coupled the guidance with special mental training to combine theory with practice.The author designed a competition train-ing program that simulates real scenarios of mental capacity,via which the players can learn how to adjust their mental state in competition,so that their technical and tactical performances are exerted steadily.

Field of study: Education
The Alchemy of Modernity. Alonso Barba's Copper Cauldrons and the Independence of Bolivian Metallurgy (1790–1890)

Those natures which, when they meet, quickly lay hold on and mutually affect one another we call affined. This affinity is sufficiently striking in the case of alkalis and acids which, although they are mutually antithetical … most decidedly seek and embrace one another, modify one another, and together form a new substance … It is in just this way that truly meaningful friendships can arise among human beings: for antithetical qualities make possible a closer and more intimate union. Goethe, Elective affinities (1809) A linear mode of historical understanding relegated alchemy to a ‘pre-scientific’ era, with the enlightenment's New Chemistry creating a break between ‘empirical’ and ‘scientific’ metallurgies. Similarly, Bolivia's early Republican silver-production has been regarded as ‘stagnant’ and ‘colonial’ from the ‘modern’ perspective of late nineteenth century liberalism. This article questions both periodisations by documenting an ‘alchemical renaissance’ in Bolivian silver-refining methods during the first part of the 19th century. The relaunch of Alonso Barba's ‘hot method’ of amalgamation in copper cauldrons (1609), and its associated technical discourses, expressed a creole desire for an independent ‘modernity’. This rediscovery of a seventeenth century technology, carried out shortly before the Independence War in the Potosí provinces (Chichas), and slightly later in Oruro and Carangas, is distinguished from the version reinvented in Central Europe by Ignaz von Born (1786), as well as from two pre-Bornian experiments in Potosí and New Spain. Its nineteenth century consolidation was, in part, a little-known reaction to Nordenflicht's failure to introduce the new European method of rotating barrels to the Andes during the 1790s. The article shows that this ‘alchemy of modernity’ held its ground for several decades, suggesting a fresh approach to America's postcolonial ambiguities from the perspective of a comparative history of technology.

Field of study: Political science
Dynamic assessment of island ecological environment sustainability under urbanization based on rough set, synthetic index and catastrophe progression analysis theories

An in-depth analysis of the main influencing factors affecting the island's ecological environment is an objective basis for accurately adjusting the island's development policies. It is of great significance to realize the coordination between island development and ecological environment. The dramatic development of Pingtan Island(PI) in the southeast coast of China has significantly impacted the survival environment. The ecological safety under island development and its driving factors should be evaluated. This paper extensively evaluates island ecological environment sustainability and builds a stress-state-response ecological environment sustainability evaluation index system that includes social economy and resource environment. This study develops a new progressive evaluation system based on the rough set, synthetic index and catastrophe progression theories.

Field of study: Environmental science