Miracle-dz/UniFAR-FTUs huggingface dataset:
The Painleve paradox in contact mechanics

The 120-year old so-called Painleve paradox involves the loss of determinism in models of planar rigid bodies in point contact with a rigid surface, subject to Coulomb-like dry friction. The phenomenon occurs due to coupling between normal and rotational degrees-of-freedom such that the effective normal force becomes attractive rather than repulsive. Despite a rich literature, the forward evolution problem remains unsolved other than in certain restricted cases in 2D with single contact points. Various practical consequences of the theory are revisited, including models for robotic manipulators, and the strange behaviour of chalk when pushed rather than dragged across a blackboard. Reviewing recent theory, a general formulation is proposed, including a Poisson or energetic impact law. The general problem in 2D with a single point of contact is discussed and cases or inconsistency or indeterminacy enumerated. Strategies to resolve the paradox via contact regularisation are discussed from a dynamical systems point of view. By passing to the infinite stiffness limit and allowing impact without collision, inconsistent and indeterminate cases are shown to be resolvable for all open sets of conditions. However, two unavoidable ambiguities that can be reached in finite time are discussed in detail, so called dynamic jam and reverse chatter. A partial review is given of 2D cases with two points of contact showing how a greater complexity of inconsistency and indeterminacy can arise. Extension to fully three-dimensional analysis is briefly considered and shown to lead to further possible singularities. In conclusion, the ubiquity of the \pain paradox is highlighted and open problems are discussed.
Religiosity and Black Adult Feelings toward Africans, American Indians, West Indians, Hispanics and Asian Americans

Abstract While religion plays a crucial role in black American life, its influence on intergroup attitudes remains little understood. Deprivation models suggest that religion acts to hinder positive race relations, while the ethnic community approach intimates that it may work to neutralize normally antagonistic feelings. Social, demographic and religious correlates of black adult racial attitudes were examined using National Study of Black American data. Multivariate analyses revealed significant gender differences. Among men the racial composition of the church was the most important determinant of positive attitudes. In contrast, among women subjective religiosity was crucial in explaining positive feelings toward Asian and Hispanic Americans, American Indians, West Indians and black Africans. The results lend support to the ethnic community model.
Reading and Related Skills in the Early School Years: Are boys really more likely to struggle?

This study examined whether boys and girls in the early school years differed in reading and related skills, and their rates of progress. Gender ratios were calculated to ascertain whether there were more boys than girls who struggle with different facets of reading, and whether the variability of boys’ scores resulted in more boys being identified as poor readers, as evidenced by previous studies. A sample of 335 students in Years 1 and 2 were administered six reading and related assessments. Boys and girls did not significantly differ on any of the measures, and differences in gains were negligible. Boys did not consistently demonstrate significantly greater variability in scores (with the exception of single-word reading and spelling in Year 1 only). These differences, however, did not affect gender ratios for poor performance. Gender ratios were relatively low across measures, but increased with years of schooling. Implications of the results are discussed.
Solving very large crew scheduling problems to optimality

In this article, we present a hybrid methodology for the exact solution of large scale real world crew scheduling problems. Our approach integrates mathematical programming and constraint satisfaction techniques, taking advantage of their particular abilities in modeling and solving specific parts of the problem. An Integer Programming framework was responsible for guiding the overall search process and for obtaining lower bounds on the value of the optimal solution. Complex constraints were easily expressed, in a declarative way, using a Constraint Logic Programming language. Moreover, with an effective constraint-based model, the huge space of feasible solutions could be implicitly considered in a fairly efficient way. Our code was tested on real problem instances arising from the daily operation of an ordinary urban transit company that serves a major metropolitan area with an excess of two million inhabitants. Using a typical desktop PC, we were able find, in an acceptable running time, an optimal solution to instances with more than 1.5 billion entries.
Growing in digital maturity: students and their computers in an academic laptop programme in Singapore

Using data collected through two focus group interviews with 14- to 16-year-olds involved in a one-to-one laptop academic programme in a Singapore secondary school, this paper shows some student disengagement and dissatisfaction in class, and this poses questions about the relevance of the school's laptop programme. Our findings illustrate low productivity in the students' use of their computers as they respond to their teachers' instructional agendas. Our work indicates research into one-to-one laptop learning needs to pay greater attention to the minds, motivations and hands of students as they embark on learning they do not fully understand or can control for themselves. We determine that educators and policy-makers need to know a lot more about how growth in students' digital maturity operates. In the final analysis, we understand and explain the students' views about how their learning experiences might be improved, and their behaviour (as a digital wisdom journey centred on learning) to be digitally mature.
Production of citric acid by Aspergillus niger using pineapple waste

A solid state fermentation was developed for citric acid production from pineapple waste by Aspergillus niger KS-7. The medium was supplemented with different concentration of glucose, sucrose, ammonium nitrate and ammonium phosphate. It was found that pineapple waste with 15% (w/v) sucrose and ammonium nitrate (0.25% w/v) gave the optimum citric acid secretion (60.61 g/kg) in the presence of methanol (2% v/v) when fermented for 5 days at 30 °C with the initial moisture content of 65%. The yield was more than 90% based on the amount of fermentable sugar consumed. These results present the use of pineapple peel as a cheap medium for the production of commercially valuable organic acid by A. niger.
Culture, social relationships and self-perceptions of Pentecostal women

English Women dominate Pentecostal worship internationally and are particularly affected by the religious, social and economic consequences of the Pentecostal movement. Drawing from cross-cultural ethnographic studies, this article describes ways Pentecostalism influences women's self-perceptions and social relationships. Discussion of social work implications addresses individual and community practice issues. French Les répercussions religieuses, sociales et économiques du mouvement pentecotiste ont particulièrement affectéles femmes, qui sont en nombre majoritaire dans ce mouvement, à l'échelle internationale. S'appuyant sur des études ethnographiques interculturelles, cette étude décrit la façon dont la participation des femmes au mouvement pentecotiste affecte leur perception de soi et leurs relations sociales. Les discussions sur les implications du travail social portent notamment sur l'attention à la vision du monde, les attentes économiques, la violence conjugale et la coopération. Spanish Las consecuencias religiosas, sociales y económicas del movimiento pentecostal han afectado a las mujeres de una forma especial, ya que internacionalmente ellas dominan los servicios religiosos. Partiendo de estudios etnográficos interculturales, se describe de quéforma la participación pentecostal afecta las auto-percepciones y relaciones sociales de las mujeres. Las implicaciones para el trabajo social incluyen atención a la cosmovisión, expectativas económicas, maltrato marital, y colaboración.
Shaming Encounters: Reflections on Contemporary Understandings of Social Inequality and Health

The idea that social inequality has deleterious consequences for population health is well established within social epidemiology and medical sociology (Marmot and Wilkinson, 2001; Scambler, 2012). In this article, we critically examine arguments advanced by Wilkinson and Pickett in The Spirit Level (2009) that in more unequal countries population health suffers, in part, because of the stress and anxiety arising from individuals making invidious or shame-inducing comparisons with others regarding their social position. We seek to extend their arguments, drawing on sociologically informed studies exploring how people reflect on issues of social comparison and shame, how they resist shame, and the resources, such as ‘collective imaginaries’ (Bouchard, 2009), which may be deployed to protect against these invidious comparisons. We build on the arguments outlined in The Spirit Level, positing a sociologically informed account of shame connected to contemporary understandings of class and neoliberalism, as well as inequality.
Effects of Serial Passage on the Characteristics and Chondrogenic Differentiation of Canine Umbilical Cord Matrix Derived Mesenchymal Stem Cells

Mesenchymal stem cells (MSCs) are often known to have a therapeutic potential in the cell-mediated repair for fatal or incurable diseases. In this study, canine umbilical cord MSCs (cUC-MSCs) were isolated from umbilical cord matrix (n = 3) and subjected to proliferative culture for 5 consecutive passages. The cells at each passage were characterized for multipotent MSC properties such as proliferation kinetics, expression patterns of MSC surface markers and self-renewal associated markers, and chondrogenic differentiation. In results, the proliferation of the cells as determined by the cumulative population doubling level was observed at its peak on passage 3 and stopped after passage 5, whereas cell doubling time dramatically increased after passage 4. Expression of MSC surface markers (CD44, CD54, CD61, CD80, CD90 and Flk-1), molecule (HMGA2) and pluripotent markers (sox2, nanog) associated with self-renewal was negatively correlated with the number of passages. However, MSC surface marker (CD105) and pluripotent marker (Oct3/4) decreased with increasing the number of subpassage. cUC-MSCs at passage 1 to 5 underwent chondrogenesis under specific culture conditions, but percentage of chondrogenic differentiation decreased with increasing the number of subpassage. Collectively, the present study suggested that sequential subpassage could affect multipotent properties of cUC-MSCs and needs to be addressed before clinical applications.
Multi-level spectral hypergraph partitioning with arbitrary vertex sizes

This paper presents a new spectral partitioning formation which directly incorporates vertex size information. The new formulation results in a generalized eigenvalue problem, and this problem is reduced to the standard eigenvalue problem. Experimental results show that incorporating vertex sizes into the eigenvalue calculation produces results that are 50% better than the standard formation in terms of scaled ratio-cut cost, even when a Kernighan-Lin style iterative improvement algorithm taking into account vertex sizes is applied as a post-processing step. To evaluate the new method for use in multi-level partitioning, we combine the partitioner with a multi-level bottom-up clustering algorithm and an iterative improvement algorithm for partition refinement. Experimental results show that our new spectral algorithm is more effective than the standard spectral formulation and other partitioners in the multi-level partitioning of hypergraphs.
Joint assessment of handedness and footedness through latent class factor analysis

ABSTRACT Recently, some studies have demonstrated the effectiveness of two latent variable approaches in which hand preferences are analysed using either latent class methods or latent class factor (LCF) methods. The main aims of this study are: (i) to establish whether these approaches are adequate for assessing footedness, (ii) to evaluate their appropriateness when hand and foot preferences are jointly analysed, and (iii) to measure the association between handedness and footedness based on the examined latent variable models. To this end, a dataset providing information about the limb used to perform ten hand actions and three foot movements by 2236 young Italian sportspeople is analysed. The first aim is pursued through an exploratory analysis of the observed foot preferences; according to this analysis, footedness patterns are adequately described by two latent levels of footedness. As far as the second aim is concerned, a confirmatory analysis of foot and hand preferences is carried out; the best fit to the dataset is obtained using a two-dimensional LCF model with four latent levels of handedness and two latent levels of footedness. Finally, the association between handedness and footedness resulting from the employed methods is remarkably lower than that registered in other studies.
Pluralistic approaches to languages in the curriculum: the case of French-speaking Switzerland, Spain and Austria

While the idea of plurilingual competence is widely established theoretically and promoted in European language policies, it is not implemented in educational practice, where separate plurilingualism is still dominant. The idea of languages as autonomous entities is e.g. reflected in the Common European Framework of Reference for Languages (CEFR) scales. The paper introduces to the Framework of Reference for Pluralistic Approaches to Languages and Cultures (FREPA). Pluralistic approaches use teaching and learning activities involving several (i.e. more than one) varieties of language, e.g. the language(s) of schooling, foreign languages, regional, minority and migration languages. FREPA thereby offers tools to put the theoretical insights and language policies into practice. The article illustrates how pluralistic approaches, in recent years, have been used in the process of large-scale national and regional curriculum renewals in Austria, French-speaking Switzerland and Spain. By promoting plurilingual education on the macro-level and including languages that are still neglected in most European curricula, these countries make a key contribution to diminishing discrepancy between theory and practice. The three cases manifest the context specificity of language-planning decisions and support supra-level comparisons by defining the specific aims and contents of plurilingual education. Furthermore, the curricular implementations offer the possibility to discuss the implementation in actual classroom practice.
Monocyte and Neutrophil Adhesion Molecule Expression During Acute Hyperglycemia and After Antioxidant Treatment in Type 2 Diabetes and Control Patients

Objective—We hypothesized that acute hyperglycemia (an independent cardiovascular risk factor) increases the expression of proatherogenic leukocyte adhesion molecule in type 2 diabetes and controls and that the expression of these adhesion molecules would be antioxidant sensitive. Methods and Results—Twenty-three type 2 diabetes patients and 13 control patients underwent two oral glucose tolerance tests 14 days apart and took placebo or 800 IU daily of oral alpha tocopherol between tests. Monocyte and neutrophil expression of adhesion molecules Mac-1, LFA-1 and 3, ICAM-1, and VLA-4 were measured at 0, 120, and 240 minutes by using laser flow cytometry. Baseline adhesion molecule expression did not differ between groups, but there was a rapid, highly significant increase (P <0.0001) in the intensity of monocyte Mac-1 expression after a glucose load in both groups. Alpha-tocopherol supplementation reduced only Mac-1 expression in the diabetes group (P =0.03) . Conclusions—Acute glycemic excursions of any degree cause highly significant, rapid increases in monocyte Mac-1 expression in type 2 diabetes patients and controls. Mac-1 mediates leukocyte vascular infiltration and is prothrombotic. These data suggest a mechanism for the link between glycemic excursions and increased vascular event rates.
Tissue-Engineered Tendon for Enthesis Regeneration in a Rat Rotator Cuff Model

Abstract Healing of rotator cuff (RC) injuries with current suture or augmented scaffold techniques fails to regenerate the enthesis and instead forms a weaker fibrovascular scar that is prone to subsequent failure. Regeneration of the enthesis is the key to improving clinical outcomes for RC injuries. We hypothesized that the utilization of our tissue-engineered tendon to repair either an acute or a chronic full-thickness supraspinatus tear would regenerate a functional enthesis and return the biomechanics of the tendon back to that found in native tissue. Engineered tendons were fabricated from bone marrow-derived mesenchymal stem cells utilizing our well-described fabrication technology. Forty-three rats underwent unilateral detachment of the supraspinatus tendon followed by acute (immediate) or chronic (4 weeks retracted) repair by using either our engineered tendon or a trans-osseous suture technique. Animals were sacrificed at 8 weeks. Biomechanical and histological analyses of the regenerated enthesis and tendon were performed. Statistical analysis was performed by using a one-way analysis of variance with significance set at p < 0.05. Acute repairs using engineered tendon had improved enthesis structure and lower biomechanical failures compared with suture repairs. Chronic repairs with engineered tendon had a more native-like enthesis with increased fibrocartilage formation, reduced scar formation, and lower biomechanical failure compared with suture repair. Thus, the utilization of our tissue-engineered tendon showed improve enthesis regeneration and improved function in chronic RC repairs compared with suture repair. Clinical Significance: Our engineered tendon construct shows promise as a clinically relevant method for repair of RC injuries.
New MRI method with contrast based on the macromolecular characteristics of tissues

A new MRI method with a contrast that is derived from the macromolecular composition and spin dynamics in the tissue is described and demonstrated on excised mouse brain and rat spinal cord. In the method, magnetization is selectively excited in the macromolecules by using a double quantum filter and subsequently transferred to water. The new imaging method differs from previous methods that rely on magnetization transfer contrast (MTC) in that it enables a separate and independent control of the effect of the macromolecule characteristics, chemical exchange, and water‐related parameters on the images. Magn Reson Med 50:229–234, 2003. © 2003 Wiley‐Liss, Inc.
Promoting phonological awareness skills of Egyptian kindergarteners through dialogic reading

The present study examines the effect of dialogic reading (DR) on the promotion of Arabic phonological awareness skills (including syllable awareness, rhyme awareness, and phoneme awareness) of Egyptian kindergarteners. The participants were 67 children enrolled in the second level of kindergarten (ages 5–6), assigned to an experimental group (n = 35) or a control group (n = 32). Kindergarten Inventory of Phonological Awareness was developed by the author in the light of relevant previous studies. Pre-tests and post-tests were administered to the participants in the two groups. In between the two tests, the experimental group engaged in DR activities designed to improve their phonological awareness skills, using an alphabet storybook, designed and developed by the author, presented to the whole class via PowerPoint, while the control group participated in regular classroom activities. The findings suggest that children in the experimental group had higher phonological awareness levels in the post-tests than those in the control group. The specific design of the DR activities may be responsible for these changes.
Dark and Baryonic Matter in Bright Spiral Galaxies. II. Radial Distributions for 34 Galaxies

We decompose the rotation curves of 34 bright spiral galaxies into baryonic and dark matter components. Stellar mass profiles are created by applying color-M/L relations to near-infrared and optical photometry. We find that the radial profile of the baryonic-to-dark-matter ratio is self-similar for all galaxies, when scaled to the radius at which the contribution of the baryonic mass to the rotation curve equals that of the dark matter (RX). We argue that this is due to the quasi-exponential nature of disks and rotation curves that are nearly flat after an initial rise. The radius RX is found to correlate most strongly with baryonic rotation speed, such that galaxies with RX measurements that lie further out in their disks rotate faster. This quantity also correlates very strongly with stellar mass, Hubble type, and observed rotation speed; B-band central surface brightness is less related to RX than these other galaxy properties. Most of the galaxies in our sample appear to be close to maximal disk. For these galaxies, we find that maximum observed rotation speeds are tightly correlated with maximum rotation speeds predicted from the baryon distributions, such that one can create a Tully-Fisher relation based on surface photometry and redshifts alone. Finally, we compare our data to the NFW parameterization for dark matter profiles with and without including adiabatic contraction as it is most commonly implemented. Fits are generally poor, and all but two galaxies are better fit if adiabatic contraction is not performed. In order to have better fits, and especially to accommodate adiabatic contraction, baryons would need to contribute very little to the total mass in the inner parts of galaxies, seemingly in contrast with other observational constraints.