nils-herrmann/clean_scirepeval huggingface dataset:
Moving Averages of Homogeneous Random Fields

Let X(g) be a homogeneous random field on a discrete locally compact Abelian group G. Let H(X) be the linear completion of {X(g): g E G} in L2 space. The following result is obtained: there exists a fundamental random field Y(g) on G with values in H(X) such that X(g) is obtained as a moving average of Y(g) if, and only if, X(g) has a spectral density which is positive almost everywhere with respect to the Haar measure on the dual group of G.

Field of study: Mathematics
The Wartime Problems of College Students

T HE dislocations of war have produced no new needs of students with which general or liberal education has not long been concerned. They have, however, accentuated many problems and put them in new settings. War dislocations have dramatically affected students' interests and motives. The immediate difficulties of living a good life, for example, are so great that they tax the resources of the students and have profound implications for the strategy of teaching. Because of the relation of the wartime concerns of students to educational planning, the central staff and a number of the colleges of the Co-operative Study in General Education have attempted to determine just what problems students really have. In February, 1942, and again in November, students wrote unsigned essays in response to the question, "What difficulties or concerns have you experienced, or do you expect to face, as a result of the war?" Nine hundred students from 7 colleges wrote replies in February;' fifteen hundred students from 13 colleges wrote replies in November. In each

Field of study: Education
Study on an Improved Algorithm for TNAM of Gray Images

The image representation is one of the most important research contents in robotics,image processing,pattern recognition,and so on. By studying the image representation methods of the popular linear quadtree and the Triangle Non-symmetry and Anti-packing pattern representation Model (TNAM),in this paper,we present an improved algorithm for TNAM of gray images. Also,we analyze the storage structure and the total data amount of the improved algorithm. The theoretical and experimental results presented in this paper show that the improved representation method for TNAM of gray images can reduce the data storage much more effectively than the representation methods of the popular linear quadtree and the TNAM and it is a better method to represent the gray image pattern.

Field of study: Computer science
A phase-retrieval toolbox for X-ray holography and tomography

This article describes scientific software made publicly available for phase retrieval in X-ray propagation imaging. The package is called HoloTomoToolbox and comprises a set of algorithms for phase retrieval in the direct-contrast regime, as well as in the holographic regime, which is used for high-resolution cone-beam synchrotron recordings. Further to this, a set of routines is included to facilitate the conversion of the 2D phase projections in a 3D tomogram.

Field of study: Physics
Scanning superconducting quantum interference device on a tip for magnetic imaging of nanoscale phenomena.

We describe a new type of scanning probe microscope based on a superconducting quantum interference device (SQUID) that resides on the apex of a sharp tip. The SQUID-on-tip is glued to a quartz tuning fork which allows scanning at a tip-sample separation of a few nm. The magnetic flux sensitivity of the SQUID is 1.8 μΦ(0)/√Hz and the spatial resolution is about 200 nm, which can be further improved. This combination of high sensitivity, spatial resolution, bandwidth, and the very close proximity to the sample provides a powerful tool for study of dynamic magnetic phenomena on the nanoscale. The potential of the SQUID-on-tip microscope is demonstrated by imaging of the vortex lattice and of the local ac magnetic response in superconductors.

Field of study: Physics
How developers micro-optimize Android apps

Optimizing mobile apps early on in the development cycle is supposed to be a key strategy for obtaining higher user rankings, more downloads, and higher retention. In fact, mobile platform designers publish specific guidelines, and tools aimed at optimizing apps. However, little research has been done with respect to identifying and understanding actual optimization practices performed by developers. In this paper, we present the results of three empirical studies aimed at investigating practices of Android developers towards improving the performance of their apps, by means of micro-optimizations. We mined change histories of 3513 apps to identify the most frequent micro-optimization opportunities in 297K+ snapshots and to understand if (and when) developers implement these optimizations. Then, we performed an in-depth analysis into whether implementing micro-optimizations can help reduce memory/CPU usage. Finally, we conducted a survey with 389 open-source developers to understand how they use micro-optimizations to improve the performance of Android apps. Surprisingly, our results indicate that developers rarely implement micro-optimizations. Also, the impact of the analyzed micro-optimization on CPU/memory consumption is negligible in most of the cases. Finally, the results from the survey shed some light into why this happens as well as upon which practices developers rely upon.

Field of study: Computer science, Engineering
CYCLOADDITION REACTION OF 3-CYANOINDOLIZINES WITH DIMETHYL ACETYLENEDICARBOXYLATE —FORMATION OF CYCL[3.2.2]AZINES AND 1:2 ADDUCTS

3-Cyano- and 3-cyano-6,8-dimethylindolizines (1a) and (1b) react with dimethyl acetylenedicarboxylate in refluxing toluene in the presence of Pd–C to give the cycl[3.2.2]azines (4a) and (4b), respectively, while 3-cyano-7-methyl- and 3-cyano-7-benzylindolizines (1c) and (1d) affording the 1:2 adducts (6c) and (6d) along with cycl[3.2.2]azine (4d).

Field of study: Chemistry
Review of researches on core stability and core strength

The authors gave an overview of the definition of core stability and core strength,determination and classification of core muscles,characteristics,functions,methods and means of core stability and core strength training,measurement and evaluation of core strength,application of core strength in event specific training,and relations between core strength and traditional strength,and drew the following conclusions: major areas of the body core are composed of the waist,pelvis and hips joint;core stability training can stabilize the back bone and strength delivery;training should be carried out in a gradually intensified way;stability is relative and dynamic;core stability and core strength are mutually restricting and promoting.The keys to future researches are to blend core strength training,traditional strength training and event specific strength training together,and to develop a new way for even specific strength training.

Field of study: Education
Study on the processing technology of litchi health oral solution

The optimum conditions for extracting juice from dried litchi were studied by orthogonal experiment,while researches were made on the methods of removing astringent flavor substances from litchi juice and the processing techniques of litchi health oral solution. The results showed that the optimum conditions for extracting juice from dried litchi were as follows: 40℃, 1∶8(dried litchi/water), enzymes 40mg/kg, 40minutes. Litchi health oral solution comprised components as follows: original juice included 70% extracted juice from dried litchi and 30% extracted juice from Chinese traditional medicines, add additional 12%～14% sugar, 1%～3% refine lecithin and 0.1%～0.3% taurine. Glutin with 0.1% was used in removing astringent flavor substances during processing.

Field of study: Agricultural and Food sciences
Amyloid beta peptides activate the phosphoinositide signaling pathway in oocytes expressing rat brain RNA.

Amyloid beta peptides (Abetas) of 39-43 amino acids constitute the major protein component of the amyloid plaques found in Alzheimer's disease brain. The generation of Abetas is regulated by the phosphoinositide (PI) pathway, which commonly couples to transmitter receptors. This study reports evidence for the activation of the PI pathway by Abetas in Xenopus oocytes expressing rat brain RNA. The naturally occurring peptides Abeta1-40 and Abeta1-42 were both active, whereas the cytotoxic fragment Abeta25-35 and the reverse peptide Abeta40-1 did not stimulate the PI pathway. Abetas rapidly lost potency in solution, suggesting that they were active only in their non-aggregated form. The Abeta response was saturable and not reduced by a substance P antagonist. This pharmacology excludes the participation of known Abeta binding proteins. The results indicate that a PI coupled receptor for non-aggregated Abeta may be present in brain.

Field of study: Biology
Can economic incentives enhance adoption and use of a household energy technology? Evidence from a pilot study in Cambodia

While much work has examined approaches to increase uptake of a variety of household environmental, health and energy technologies, researchers and policymakers alike have struggled to ensure long-term use. Drawing on a pilot-scale experiment conducted in rural Cambodia, this study evaluates whether economic incentives enhance continued use of—and fuel savings from—improved cookstoves (ICS). Capital-cost subsidies that have been traditionally employed to enhance ICS adoption were augmented with rebates linked to stated and objectively measured use in order to investigate impacts on both initial and sustained adoption in the treatment group. Results show that households do respond to these rebates by adopting the intervention ICS at significantly higher rates, and by using it more frequently and for longer periods. Consistent with these stove-use patterns, solid-fuel use and time spent collecting or preparing fuels also decline. However, this effect appears to diminish over time. Thus, while economic inducements may significantly increase adoption and use of new environmental health technologies, corresponding reductions in environmental or livelihood burdens are not guaranteed. Additional research on the design and implementation of incentive-based interventions targeting households directly—such as carbon financing or other forms of results-based financing (RBF) for improved cookstoves—therefore seems warranted prior to wider implementation of such solutions.

Field of study: Environmental science
Detecting competition in the fossil record: Support for character displacement among Ordovician brachiopods

In an effort to further our understanding of ecosystem structure on multiple temporal and biogeographic scales, the influence of competitive interactions in an invasive setting was explored in the fossil record. Using brachiopod morphology as a proxy for niche space occupation, the external shapes of three pairs of potentially competing brachiopod species were analyzed via three-dimensional baseline shape co-ordinates. Morphology of incumbents was compared before and after the Richmondian Invasion (Late Ordovician, Illinois Basin), and for each incumbent–invader pair: it was possible to differentiate the incumbents pre- and post-invasion; the incumbent became more morphologically different from the invader; and landmarks driving the morphological differences of two of the incumbents shift away from the invader in multidimensional morphospace. These results are consistent with character displacement, which supports the hypothesis that competition played a discernable role in the brachiopod community. This suggests that the use of morphometrics and morphospace occupation could provide a valuable tool for the exploration of ecological interactions in the geologic record, potentially providing novel interpretations of the effects of competition on community structure and evolution.

Field of study: Environmental science, Geography
Explaining the rise in marital fertility in England in the long eighteenth century

T he two most effective ways of converting parish register data into estimates of fertility, mortality, and nuptiality in the past are generalized inverse projection and family reconstitution. In general, they produce reassuringly similar results for England in the early modem  An earlier version of inverse projection, using aggregative tabulations from 404 parishes, was employed to generate the demographic estimates presented in the Population history of England, while, 16 years later, data from 26 parish reconstitutions formed the basis for the findings published in English population history from family reconstitution.3 The far more refined measures produced by family reconstitution have enabled some of the input parameters used in inverse projection to be specified more accurately, and this in turn has led to minor modifications in the results obtained by inverse projection, but, whether the original or the modified parameters are used, comparison of the output from reconstitution and inverse projection suggests that the two methods yield the '4 same 'big picture' Nevertheless, the later reconstitution study has brought to light many previously unknown or obscure features of English population history, some of which are simultaneously illuminating and puzzling: illuminating because they enforce a revision of the received wisdom; puzzling because, although the existence of an unexpected pattern can be demonstrated, its explanation is unclear. This article explores a possible explanation of one of these new findings, the rise in marital fertility which took place during the eighteenth century, for which no satisfactory explanation was offered in English population history from family reconstitution. Most of the

Field of study: Economics, History
Radio-Absorbing Composites for Microwave Devices

Ferrite-based composites can largely attenuate the energy of incident electromagnetic radiation by reducing the reflection at the interface between the composites and free space. The magnetic and dielectric properties of composites consisting of ferrite fillers and epoxy resin are investigated along with the parameters of microwave absorption. The dependences of the permeability and permittivity in the 1 to 3 GHz range of frequencies are presented.

Field of study: Physics
The prognostic value of lymph nodes mRNA CXCL12 expression in the breast cancer

Prognosis of breast carcinoma is influenced by age, tumor size, histological grade and type, lymph node status, as well as metastasic status. Chemokine receptor CXCR-4 with its ligand, CXCL-12, may play an important role in metastasis of breast carcinoma. However, the role of CXCL-12 mRNA as a prognostic factor and a therapeutic target of human breast cancer remains controversial. This study aimed to investigate the level of CXCL-12 mRNA expression in lymph nodes of patients with invasive ductal breast carcinoma and the difference within the prognostic factors. Axillary lymph nodes obtained from 50 cases of invasive ductal breast carcinoma, were divided into two groups, with and without lymph node metastasis. Each group consisted of 25 cases. Total RNA was extracted from formalin-fixed paraffin-embedded. The CXCL-12 mRNA expression was examined using qRT-PCR method. The mean differences between the two groups were analyzed using Mann-Whitney test. The differences between CXCL-12 mRNA expression and each prognostic factor ware analyzed using Mann-Whitney comparison test. CXCL-12 mRNA expression was significantly higher in the lymph node of patients with metastasis of breast carcinoma compared to the non-metastasis cases (p<0.01). There were significant differences between CXCL-12 mRNA expression with poorly histological grade (p=0.003), bigger primary tumor size (p=0.005) and age of ≥45 y.o (p=0.012) in the metastatic group, but there were no significant differences between both age of <45 and ≥45 y.o.This study suggests that the higher CXCL-12 mRNA expression level are associated with bigger tumor size and poor differentiation in breast cancer patient with lymph nodes metastasis

Field of study: Medicine
Assured forwarding fairness using equation-based packet marking and packet separation

Fairness is one of the important problems in assured forwarding (AF) performance in the differentiated services (DiffServ) framework [An architecture for differentiated services, RFC 2475, IETF, December 1998; A two-bit differentiated services architecture for the Internet, Internet-draft, draft-nichols-diff-svc-arch-02.pdf, IETF, April I999]. In this paper we present a two-part solution for the fairness problem in AF. The first part is a new packet marking algorithm called equation-based marking (EBM) and is based on the TCP model given by Padhye et al.  EBM is to handle the problems found in other marking schemes regarding fairness among heterogeneous TCP flows through a tight feedback-loop operation and adaptation of the packet marking probability to network conditions. The second part is called packet separation used at routers to handle the fairness between responsive and nonresponsive traffic. We evaluate the performance of a packet marker that uses EBM as the marking algorithm using in-depth simulation. We prove, analytically and using simulation, the correctness of the marking algorithm and compare it with other marking schemes for different network scenarios. We also use simulation to show the effectiveness of the packet separation mechanism in solving the fairness problem between responsive and non-responsive traffic. Our evaluation results demonstrate the effectiveness of EBM along with packet separation in providing the required fairness among heterogeneous flows and ensuring protection against non-assured traffic.

Field of study: Computer science
The significance and the corresponding countermeasure research of launching amateur radio direction finding sport in primary and secondary school

Amateur Radio Direction Finding Sport (ARDFS) is an athletic item which combines science, technology, bodybuilding and entertainment.It accords with the physical and psychological characteristics of primary and secondany school students,so it is very popular amony them .It also has unigue effects on broadening their outlook,enriching their knowledge, strengthening their health and cultivating their comprehensive qualities.This analyzed the current situation of ARDFS in China and suggested the corresponding countermeasure so as to lauch this sport more successfully to promote students' all round development and to provide reference to the reform of PE course.

Field of study: Education
Bayesian Allocation Model: Inference by Sequential Monte Carlo for Nonnegative Tensor Factorizations and Topic Models using Polya Urns

We introduce a dynamic generative model, Bayesian allocation model (BAM), which establishes explicit connections between nonnegative tensor factorization (NTF), graphical models of discrete probability distributions and their Bayesian extensions, and the topic models such as the latent Dirichlet allocation. BAM is based on a Poisson process, whose events are marked by using a Bayesian network, where the conditional probability tables of this network are then integrated out analytically. We show that the resulting marginal process turns out to be a Polya urn, an integer valued self-reinforcing process. This urn processes, which we name a Polya-Bayes process, obey certain conditional independence properties that provide further insight about the nature of NTF. These insights also let us develop space efficient simulation algorithms that respect the potential sparsity of data: we propose a class of sequential importance sampling algorithms for computing NTF and approximating their marginal likelihood, which would be useful for model selection. The resulting methods can also be viewed as a model scoring method for topic models and discrete Bayesian networks with hidden variables. The new algorithms have favourable properties in the sparse data regime when contrasted with variational algorithms that become more accurate when the total sum of the elements of the observed tensor goes to infinity. We illustrate the performance on several examples and numerically study the behaviour of the algorithms for various data regimes.

Field of study: Computer science
Are streamside buffers edge-affected habitat for ground-dwelling forest beetle assemblages?

Reservation of forest in riparian buffers is common practice in commercial forestry areas worldwide, potentially providing valuable habitat for biodiversity dependent on mature forest. However, the habitat value of narrow reserve corridors can be compromised by edge effects. We investigated the habitat value of streamside buffers in wet eucalypt forest for ground-dwelling beetles in Tasmania, Australia. Beetles were collected with pitfall traps in five replicates of four habitats: unlogged corridors of mature forest in streamside reserves (buffers) with clearfelling-derived logging regeneration either side; continuous mature upslope forest; continuous mature riparian forest; and <20-year-old upslope clearfelling-derived logging regeneration. Streamside reserve widths on each side of the stream were on average 40 ± 6 m (±95% CI) from reserve edge to stream. Beetle assemblages in logging regeneration differed substantially from those in the unlogged habitats, including the streamside reserves. Streamside reserve assemblages nevertheless differed from those of the continuous unlogged areas. Assemblage composition in streamside reserves was most similar to that in continuous mature riparian forest, although beetle diversity was higher in the reserves. Our results suggest that although streamside reserves provide habitat for the majority of commonly collected beetle species occurring in continuous mature forest, wider reserve corridors in the wet eucalypt forests of Tasmania may be required to provide habitat that is not edge-affected.

Field of study: Environmental science
Mitochondrial aldehyde dehydrogenase polymorphism in Asian and American Indian populations: detection of new ALDH2 alleles.

Genetic deficiency of the mitochondrial aldehyde dehydrogenase (ALDH2) is frequent in Asian peoples where it is an important factor negatively regulating drinking behavior. To obtain additional information on gene geography of known ALDH2 alleles, and look for new variants, ALDH2 genes were evaluated in a Chinese population from Taiwan, a Yakut population of Siberia, and in five North American Indian populations. A novel approach based on a single-strand conformation polymorphism assay, and polymerase chain reaction-directed mutagenesis was developed for genotyping. In the Taiwan Chinese population, the ALDH2(2) allele frequency was 0.319 +/- 0.025, and this allele was not detected in the Yakut population nor in the five North American Indian populations. However, a new allele, ALDH2(3), was detected in Pima Indians at a frequency of 0.044 +/- 0.022, and this allele was also observed in 1 of 49 Pueblo samples. ALDH2(3) is a silent transition 1464 G-->A, and it possibly has a wide distribution among North American Indians. A new subtype of the ALDH2(2) allele, designated as ALDH2(2Taiwan), was found in 1 of 174 Chinese from Taiwan. ALDH2(2Taiwan) is characterized by two G-->A transitions at bases 1486 and 1510, resulting in Glu-->Lys substitutions at both the 479 and 487 positions. Thus, this second nonconservative ALDH2 substitution occurs within the sequence of the already inactive ALDH2(2) allele.

Field of study: Medicine