Miracle-dz/UniFAR-FTUs huggingface dataset:
Astrophysics Numerical Simulations of Vertical Oscillations of a Solar Coronal Loop

We consider the impulsive excitation of fast vertical kink standing waves in a solar coronal loop that is embedded in a potential arcade. The two-dimensional numerical model we implement includes the effects of field line curvature and nonlinearity on the excitation and damping of standing fast magnetosonic waves. The results of the numerical simulations reveal wave signatures which are characteristic of vertical loop oscillations seen in recent TRACE observational data.
Stirring the motivational soup

Background: The purpose of the present study was to use a person-oriented analytical approach to identify latent motivational profiles, based on the different behavioural regulations for exercise, and to examine differences in satisfaction of basic psychological needs (competence, autonomy and relatedness) and exercise behaviour across these motivational profiles. Methods: Two samples, consisting of 1084 and 511 adults respectively, completed exercise-related measures of behavioural regulation and psychological need satisfaction as well as exercise behaviour. Latent profile analyses were used to identify motivational profiles. Results: Six profiles, representing different combinations of regulations for exercise, were found to best represent data in both samples. Some profiles were found in both samples (e.g., low motivation profile, self-determined motivation profile and self-determined with high introjected regulation profile), whereas others were unique to each sample. In line with the Self-Determination Theory, individuals belonging to more self-determined profiles demonstrated higher scores on need satisfaction. Conclusions: The results support the notions of motivation being a multidimensional construct and that people have different, sometimes competing, reasons for engaging in exercise. The benefits of using person-oriented analyses to examine within-person interactions of motivation and different regulations are discussed.
An Effective Error Correction Scheme for Arithmetic Coding

We propose an effective error correction technique for arithmetic coding with forbidden symbol. By predicting the occurrence of the subsequent forbidden symbols, the forbidden region is actually expanded and theoretically, a better error correction performance can be achieved. Moreover, a generalized stack algorithm is exploited to detect the forbidden symbol beforehand. The proposed approach is combined with the maximum a posteriori (MAP) metric to keep the highly probable decoding paths in the stack. Simulation results justify that our scheme performs better than the existing MAP methods on the error correction performance, especially at a low coding rate.
Entry and Exit from Farming: Insights from 5 Rounds of Agricultural Census Data

One of the major demographic trends in the US is the aging of farm operators and landlords suggesting transition of farm ownership in the form of exit and disinvestment. This coincides with economic pressures on farmers’ incomes due to recent market volatility. We model retirement age farmers’ exit/disinvestment as the outcome of intertemporal utility maximization and identify the extent to which economic and demographic factors affect these choices using the Census of Agriculture farm-level data for the 1992-2012 period. Regression results highlight the role of demographic factors. Minority and female farmers are more likely to exit but female operators are less likely to disinvest, while family farms are less likely to exit. High sales farms are less likely to exit but more likely to disinvest possibly targeting a smaller production scale before retirement. The relative size of the non-agricultural economy is negatively associated with exit but positively with disinvestment, while off-farm work reduces exit probability only a little. However, flow economic variables such as return-on-assets and government payments do not seem to impact exit and disinvestment. These findings are largely consistent with the view that mainly demographic factors and size determine farmers’ decisions to retire, which has important policy implications.
A dramatic increase

Independent Energy recently completed its 5th annual Financial Rankings survey for all of 1994. The results show a dramatic increase in financial activity - especially during the second half of 1994. For all of 1994, developers and financial firms reported activity in project finance debt and equity, in corporate finance, and in revenue bonds totaling about $31 billion. This is up from about $17 billion in 1993. Fir the last six months of 1994, financial activity was reported at about $21 billion in these categories. This compares to $10.5 billion during the first half of 1994. The dramatic survey results can be attributed to several factors that reflect continuing industry trends. International activity in privitization and public stock offerings strengthened the results. Of 110 transactions reported for the second half of 1994, 40% were for deals outside the US. This is an increase from about 30% international transactions reported during 1994`s first half. Of the remaining transactions, many were for refinancing existing US projects. Finally, these rankings demonstrate an increase in the number of firms reporting as the industry expands globally. While the international activity in stock offerings and privitization was strong, closings for new power projects worldwide remains slow.
Performing masculinity, influencing health: a qualitative mixed-methods study of young Spanish men

Background The literature shows how gender mandates contribute to differences in exposure and vulnerability to certain health risk factors. This paper presents the results of a study developed in the south of Spain, where research aimed at understanding men from a gender perspective is still limited. Objective The aim of this paper is to explore the lay perceptions and meanings ascribed to the idea of masculinity, identifying ways in which gender displays are related to health. Design The study is based on a mixed-methods data collection strategy typical of qualitative research. We performed a qualitative content analysis focused on manifest and latent content. Results Our analysis showed that the relationship between masculinity and health was mainly defined with regard to behavioural explanations with an evident performative meaning. With regard to issues such as driving, the use of recreational drugs, aggressive behaviour, sexuality, and body image, important connections were established between manhood acts and health outcomes. Different ways of understanding and performing the male identity also emerged from the results. The findings revealed the implications of these aspects in the processes of change in the identity codes of men and women. Conclusions The study provides insights into how the category ‘man’ is highly dependent on collective practices and performative acts. Consideration of how males perform manhood acts might be required in guidance on the development of programmes and policies aimed at addressing gender inequalities in health in a particular local context.
We Feel: Mapping Emotion on Twitter

Research data on predisposition to mental health problems, and the fluctuations and regulation of emotions, thoughts, and behaviors are traditionally collected through surveys, which cannot provide a real-time insight into the emotional state of individuals or communities. Large datasets such as World Health Organization (WHO) statistics are collected less than once per year, whereas social network platforms, such as Twitter, offer the opportunity for real-time analysis of expressed mood. Such patterns are valuable to the mental health research community, to help understand the periods and locations of greatest demand and unmet need. We describe the “We Feel” system for analyzing global and regional variations in emotional expression, and report the results of validation against known patterns of variation in mood. $2.73 \times 10^{9}$ emotional tweets were collected over a 12-week period, and automatically annotated for emotion, geographic location, and gender. Principal component analysis (PCA) of the data illustrated a dominant in-phase pattern across all emotions, modulated by antiphase patterns for “positive” and “negative” emotions. The first three principal components accounted for over 90% of the variation in the data. PCA was also used to remove the dominant diurnal and weekly variations allowing identification of significant events within the data, with z-scores showing expression of emotions over 80 standard deviations from the mean. We also correlate emotional expression with WHO data at a national level and although no correlations were observed for the burden of depression, the burden of anxiety and suicide rates appeared to correlate with expression of particular emotions.
The Effect of Electroacupuncture on the Extracellular Matrix Synthesis and Degradation in a Rabbit Model of Disc Degeneration

The present study was aimed at determining if the electroacupuncture (EA) is able to protect degenerated disc in vivo. New Zealand white rabbits (n = 40) were used for the study. The rabbits were randomly assigned to four groups. EA intervention was applied to one of the four groups. Magnetic resonance imaging and Pfirrmann's classification were obtained for each group to evaluate EA treatment on the intervertebral disc degeneration. Discs were analyzed using immunofluorescence for the labeling of collagens 1 and 2, bone morphogenetic protein-2 (BMP-2), matrix metalloproteinase-13 (MMP-13), and tissue inhibitor of matrix metalloproteinase-1 (TIMP-1). For protein expression analysis, western blot was used for biglycan and decorin. Outcomes indicated that EA intervention decreased the grades compared with the compressed disc. Immunofluorescence analysis showed a significant increase of collagens 1 and 2, TIMP-1, and BMP-2 positive cells, in contrast to MMP-13 after EA treatment for 28 days. The protein expression showed a sign of regeneration that decorin and biglycan were upregulated. It was concluded that EA contributed to the extracellular matrix (ECM) anabolic processes and increased the ECM components. MMPs and their inhibitors involved in the mechanism of EA intervention on ECM decreased disc. It kept a dynamic balance between ECM synthesis and degradation.
Performance Analysis of Random Access Strategies for Short Message Exchange in VANETs: A Social Approach

Major applications of Vehicular Ad Hoc Networks (VANETs) are strongly related with safety applications like emergency warning, rescue operations, information about road conditions and accident alert. However, little attention has been given to the design of comfort applications with social approach, such as the connecting of people with common interests (like twitter or SMS services). Most of the work reported in the literature in VANETs is focused on clustering and routing schemes for the dissemination of queries in the network, however, the impact of the media access control (MAC) protocols has been largely overlooked. In this work is studied the transmission of short messages and different MAC strategies for social network applications, to operate in VANETs and pedestrian environments, are proposed. Specifically, a comprehensive study of two main random access protocols: CSMA/CA and S-ALOHA and two of the most common back off algorithms: Uniform Back off (UB) and Binary Exponential Back off (BEB) is presented. As an additional feature, the proposal of a MAC hybrid strategy to improve the system performance in terms of the success probability and delay is developed.
On the Local Well-posedness of the Prandtl and Hydrostatic Euler Equations with Multiple Monotonicity Regions

We find a new class of data for which the Prandtl boundary layer equations and the hydrostatic Euler equations are locally in time well-posed. In the case of the Prandtl equations, if the initial datum $u_0$ is monotone on a number of intervals (on some strictly increasing, on some strictly decreasing) and analytic on the complement of these intervals, we show that the local existence and uniqueness hold. The same result is true for the hydrostatic Euler equations if we assume these conditions for the initial vorticity $\omega_0=\partial_y u_0$.
Progressive teaching of mathematics with tablet technology

We investigate a multimodal approach to lecture presentation built on tablet technology. This innovative approach presents a framework which provides organizational structure to the lecture and facilitates incorporation of additional detail through electronic ink. Diagrams, solutions and concept maps are developed spontaneously in real time, thus engaging and promoting student directed learning, through a creative, interactive and dynamic process. Our study analyzes benefits and drawbacks of this approach, through evaluation of instructor experiences and student feedback for three undergraduate mathematics courses held over three consecutive semesters.
Laser Microdissection of Sensory Organ Precursor Cells of Drosophila Microchaetes

Background In Drosophila, each external sensory organ originates from the division of a unique precursor cell (the sensory organ precursor cell or SOP). Each SOP is specified from a cluster of equivalent cells, called a proneural cluster, all of them competent to become SOP. Although, it is well known how SOP cells are selected from proneural clusters, little is known about the downstream genes that are regulated during SOP fate specification. Methodology/Principal Findings In order to better understand the mechanism involved in the specification of these precursor cells, we combined laser microdissection, toisolate SOP cells, with transcriptome analysis, to study their RNA profile. Using this procedure, we found that genes that exhibit a 2-fold or greater expression in SOPs versus epithelial cells were mainly associated with Gene Ontology (GO) terms related with cell fate determination and sensory organ specification. Furthermore, we found that several genes such as pebbled/hindsight, scabrous, miranda, senseless, or cut, known to be expressed in SOP cells by independent procedures, are particularly detected in laser microdissected SOP cells rather than in epithelial cells. Conclusions/Significance These results confirm the feasibility and the specificity of our laser microdissection based procedure. We anticipate that this analysis will give new insight into the selection and specification of neural precursor cells.
Ionic Conductances of the Surface and Transverse Tubular Membranes of Frog Sartorius Fibers

The resting ionic conductances of frog sartorius muscle fibers have been determined in a variety of conditions in order to measure the potassium conductance of the tubular and surface membranes (g K t and g K s) and the chloride conductance of the tubular and surface membranes (g Cl t and g Cl s). In both normal fibers and fibers without tubules, measurements of input resistance and diameter were made at normal pH and at low pH when the chloride conductance was very small. These measurements permitted the separation of the ionic conductances: g Cl s = 219 µmhos/cm2; g Cl t = 0 µmhos/cm2; g K s = 28 µmhos/cm2; g K t = 55 µmhos/cm2. Possible sources of systematic error are discussed and a statistical analysis of the effects of random error is presented. The implications of the nonuniformity of membrane properties are discussed along with possible anatomical explanations.
Online Learning in the Embedded Manifold of Low-rank Matrices

When learning models that are represented in matrix forms, enforcing a low-rank constraint can dramatically improve the memory and run time complexity, while providing a natural regularization of the model. However, naive approaches to minimizing functions over the set of low-rank matrices are either prohibitively time consuming (repeated singular value decomposition of the matrix) or numerically unstable (optimizing a factored representation of the low-rank matrix). We build on recent advances in optimization over manifolds, and describe an iterative online learning procedure, consisting of a gradient step, followed by a second-order retraction back to the manifold. While the ideal retraction is costly to compute, and so is the projection operator that approximates it, we describe another retraction that can be computed efficiently. It has run time and memory complexity of O((n+m)k) for a rank-k matrix of dimension m×n, when using an online procedure with rank-one gradients. We use this algorithm, LORETA, to learn a matrix-form similarity measure over pairs of documents represented as high dimensional vectors. LORETA improves the mean average precision over a passive-aggressive approach in a factorized model, and also improves over a full model trained on pre-selected features using the same memory requirements. We further adapt LORETA to learn positive semi-definite low-rank matrices, providing an online algorithm for low-rank metric learning. LORETA also shows consistent improvement over standard weakly supervised methods in a large (1600 classes and 1 million images, using ImageNet) multilabel image classification task.
Open Access Renewable Resources: Trade and Trade Policy in a Two-Countrymodel

This paper develops a two-good, two-country model with national open access renewable resources. We derive an appropriate analog of `factor proportions' for the renewable resource case and link it to trade patterns and to the likelihood of diversified production. The resource importer gains from trade. However, a diversified resource exporting country necessarily suffers a decline in steady state utility resulting from trade, and may lose along the entire transition path. Thus the basic `gains from trade' presumption is substantially undermined by open access resources. Tariffs imposed by the resource importing country always benefit the resource exporter, and may be pareto-improving.
Oridonin Up-regulates Expression of P21 and Induces Autophagy and Apoptosis in Human Prostate Cancer Cells

Background: Oridonin (ORI) could inhibit the proliferation and induce apoptosis in various cancer cell lines. However, the mechanism is not fully understood. Methods: Human prostate cancer (HPC) cells were cultured in vitro and cell viability was detected by the CCK-8 assay. The ultrastructure changes were observed under transmission electron microscope (TEM). Chemical staining with acridine orange (AO), MDC or DAPI was used to detect acidic vesicular organelles (AVOs) and alternation of DNA. Expression of LC3 and P21 was detected by Western Blot. Apoptotic rates and cell cycle arrest were detected by FACS. Results: Our study demonstrated that after ORI treatment, the proliferations of human prostate cancer (HPC) cell lines PC-3 and LNCaP were inhibited in a concentration and time-dependent manner. ORI induced cell cycle arrest at the G2/M phase. A large number of autophagosomes with double-membrane structure and acidic vesicular organelles (AVOs) were detected in the cytoplasm of HPC cells treated with ORI for 24 hours. ORI resulted in the conversion of LC3-I to LC3-II and recruitment of LC3-II to the autophagosomal membranes. Autophagy inhibitor 3-methyladenine (3-MA) reduced AVOs formation and inhibited LC3-I to LC3-II conversion. At 48 h, DNA fragmentation, chromatin condensation and disappearance of surface microvilli were detected in ORI-treated cells. ORI induced a significant increase in the number of apoptotic cells (PC-3: 5.4% to 27.0%, LNCaP: 5.3% to 31.0%). Promoting autophagy by nutrient starvation increased cell viability, while inhibition of autophagy by 3-MA promoted cell death. The expression of P21 was increased by ORI, which could be completely reversed by the inhibition of autophagy. Conclusions: Our findings indicated that autophagy occurred before the onset of apoptosis and protected cancer cells in ORI-treated HPC cells. P21 was involved in ORI-induced autophagy and apoptosis. Our results provide an experimental basis for understand the anti-tumor mechanism of ORI as treatment for prostate cancer.
Drawing Clustered Graphs Using Stress Majorization and Force-Directed Placements

We propose a novel layout algorithm to draw clustered graphs. Our algorithm applies a stress model to draw intra-cluster graphs and a spring-electrical force model to place clusters. Our strategy modifies the original stress model in graph drawing by integrating the force from the center to push and pull the intra-cluster nodes based on their outside connectivity. We also apply the idea of torque equilibrium, coupled with some heuristics, to realize our force-directed placement algorithm. To show the effectiveness of our design, we compare the running time and the number of edge crossings experimentally with the one using full stress majorization as well as other clustered graph drawing algorithms available in the literature. Our experimental results look promising.
The forgotten monoid

We study properties of the forgotten monoid which appeared in work of Lascoux and Schutzenberger and recently resurfaced in the construction of dual equivalence graphs by Assaf. In particular, we provide an explicit characterization of the forgotten classes in terms of inversion numbers and show that there are n^2-3n+4 forgotten classes in the symmetric group S_n. Each forgotten class contains a canonical element that can be characterized by pattern avoidance. We also show that the sum of Gessel's quasi-symmetric functions over a forgotten class is a 0-1 sum of ribbon-Schur functions.
Distributed collaborative filtering over social networks

Recommender systems predict user preferences based on a range of available information. For systems in which users generate streams of content (e.g., blogs, periodically-updated newsfeeds), users may rate the produced content that they read, and be given accurate predictions about future content they are most likely to prefer. We design a distributed mechanism for predicting user ratings that avoids the disclosure of information to a centralized authority or an untrusted third party: users disclose the rating they give to certain content only to the user that produced this content. We demonstrate how rating prediction in this context can be formulated as a matrix factorization problem. Using this intuition, we propose a distributed gradient descent algorithm for its solution that abides with the above restriction on how information is exchanged between users. We formally analyse the convergence properties of this algorithm, showing that it reduces a weighted root mean square error of the accuracy of predictions. We also demonstrate how this technique can readily be used to offer optimal recommendation.