Miracle-dz/UniFAR-FTUs huggingface dataset:
On the Feasibility of Interference Alignment for the K-User MIMO Channel with Constant Coefficients

In this paper, we consider the feasibility of linear interference alignment (IA) for multiple-input multiple-output (MIMO) channels with constant coefficients for any number of users, antennas and streams per user. We combine algebraic geometry techniques with differential topology ones and prove much stronger results than those previously published on this topic. Specifically, we consider the input set (complex projective space of MIMO interference channels), the output set (precoder and decoder Grassmannians) and the solution set (channels, decoders and precoders satisfying the IA polynomial equations), not only as algebraic sets but also as smooth compact manifolds. The main result of the paper states that the linear alignment problem is feasible when the algebraic dimension of the solution variety is larger or equal than the dimension of the input space and the linear mapping between the tangent spaces of both smooth manifolds given by the first projection is surjective. If that mapping is not surjective, then the solution variety projects into the input space in a singular way and the projection is a zero-measure set. Building on these results, another contribution of the paper is to propose a simple, polynomial-complexity test of feasibility for the linear alignment problem. O. González and I. Santamaría are with the Communications Engineering Department (DICOM), University of Cantabria, Santander, 39005, Spain. C. Beltrán is with the Departamento de Matemáticas, Estadística y Computación, Universidad de Cantabria. Avda. Los Castros s/n, Santander, Spain. The work of O. González and I. Santamaría was supported by MICINN (Spanish Ministry for Science and Innovation) under grants TEC2010-19545-C04-03 (COSIMA), CONSOLIDER-INGENIO 2010 CSD2008-00010 (COMONSENS) and FPU grant AP2009-1105. Carlos Beltrán was partially supported by MICINN grant MTM2010-16051. February 1, 2012 DRAFT
Ultrasound guided injection of recalcitrant plantar fasciitis

OBJECTIVE To determine the effect of ultrasound guided injection in recalcitrant idiopathic plantar fasciitis. METHODS Four patients with a clinical diagnosis of idiopathic plantar fasciitis, who were unresponsive to palpation guided injection with triamcinolone acetonide and local anaesthetic, underwent ultrasonographic examination of the heel. RESULTS The following ultrasonographic features were noted:- (a) increased thickness of plantar fascia in symptomatic heels compared with asymptomatic heels, (b) loss of distinction of the distal plantar fascia borders, (c) reduced echogenicity of the plantar fascia. Ultrasound guided injection of the enlarged, hypoechoic plantar fascia resulted in complete relief in four of five heels(mean duration of follow up=24 months) in three cases. One patient developed a recurrence of symptoms after six months. CONCLUSION Ultrasound allows for confirmation of the clinical diagnosis and ultrasound guided injection produces a good clinical response when unguided injection is unsuccessful. The technique is quick, inexpensive, and entails no radiation exposure.
Circulating Programmed Death-1 as a Marker for Sustained High Hepatitis B Viral Load and Risk of Hepatocellular Carcinoma

Objective Recent evidence indicates a crucial role of the immunoinhibitory receptor programmed death-1 (PD-1) in enforcing T-cell dysfunction during chronic viral infection and cancer. We assessed the impact of circulating soluble PD-1 (sPD-1) levels on long-term dynamics of hepatitis B virus (HBV) load and hepatocellular carcinoma (HCC) risk. Methods In a case-cohort study on longitudinal analysis of viral load within a cohort of 2903 men chronically infected with HBV, followed up from baseline (1989–1992) through 2010, we determined sPD-1 levels in baseline plasma with enzyme-linked immunosorbent assay from 126 men who subsequently developed HCC and 1155 men who did not develop HCC. To evaluate whether patients' characteristics involved the use of sPD-1 as a biomarker, sPD-1 was also tested in 614 newly-diagnosed patients with HBV-related HCC recruited from a multicenter study for comparison with the 1155 noncases in the case-cohort study. Results Plasma quartile levels of sPD-1 were positively associated with HCC risk for men in the case-cohort analysis (vs. quartile 1: adjusted odds ratios [95% confidence intervals] for quartile 2-quartile 4 were 1.51 [0.75–3.03], 2.15 [1.12–4.13], and 2.29 [1.20–4.38], respectively), and in the case-control study regardless of age-of-onset and clinical stage. Furthermore, we found longitudinal effect of elevated sPD-1 levels to maintain higher viral load for 4 or more years, with greater and more prolonged effect among HBV genotype C- vs. non-C-infected participants. High levels of viral load and sPD-1 (vs. absence of both) was associated with a 6.29-fold increase in risk of HCC, and combining both conditions with HBV genotype C yielded an odds ratio of 30.47 with significant additive interaction (relative excess risk due to interaction: 27.08 [95% confidence interval = 8.76–45.41]). Conclusions Our data suggest plasma sPD-1 as an important immune-related marker for assessment of HBV activity and HCC risk.
Sharp Upper Bounds for Multiplicative Zagreb Indices

For a (molecular) graph, the multiplicative Zagreb indices ∏ 1-index and ∏ 2index are multiplicative versions of the ordinary Zagreb indices (M1-index and M2index). In this note we report several sharp upper bounds for ∏ 1-index in terms of graph parameters including the order, size, radius, Wiener index and eccentric distance sum, and upper bounds for ∏ 2-index in terms of graph parameters including the order, size, the first Zagreb index, the first Zagreb coindex and degree distance. ∗Corresponding author. E-mail address: qhzhangmath@yeah.net (Q. Zhang) MATCH Communications in Mathematical and in Computer Chemistry MATCH Commun. Math. Comput. Chem. 68 (2012) 231-240
Time Consistent Risk Measure Under Stopping Time Framework and its Applications ∗

For financial investment with a pre-specified investment target, the risk can be regarded as the uncertainty of the earliest target reaching time. As a refinement of this new perspective of risk measure, we introduce a new risk measure which is the extra time cost between the current time and the earliest time that the investment achieves the target or beats the benchmark at some confidence level. The new risk measure is based on a probabilistic constraint and can be seen as a generalization of the payback period method in corporate financial management. We show that the new risk measure has good properties such as normalization, monotonicity, positive homogeneity and weak time consistency. We also discuss the relationship between the new risk measure and variance and VaR. Then we consider two applications of the new measure, the theoretical application is the introduction of arbitrage with probability, which extends the usual definition of arbitrage opportunity and can help the investor differentiate markets which are arbitrage free; the practical application is the multi-period portfolio selection. For the chance constrained multi-period investment decision problem constructed under the new measure, we use the Chebyshev inequality ∗This research was supported by the National Natural Science Foundation of China (Grant Numbers 70971109 and 71371152). †The corresponding author: zchen@mail.xjtu. edu.cn
Interest—The Curious Emotion

Despite their interest in why people do what they do, psychologists typically overlook interest itself as a facet of human motivation and emotion. In recent years, however, researchers from diverse areas of psychology have turned their attention to the role of interest in learning, motivation, and development. This article reviews the emerging body of work on the psychology of interest, with an emphasis on what contemporary emotion research has learned about the subject. After considering four central questions—Is interest like other emotions? What functions does interest serve? What makes something interesting? Is interest merely another label for happiness? —the article considers unanswered questions and fruitful applications. Given interest's central role in cultivating knowledge and expertise, psychologists should apply research on interest to practical problems of learning, education, and motivation.
Negatively Disinhibited Online Communication: The Role of Visual Anonymity and Public Self-Awareness

ii Acknowledgments.v Vita. vi List of Tables . x List of Figures . xii Chapter 1: Introduction . 1 Chapter 2: Background and Literature review . 4 Consequences of Visual Anonymity . 4 Explaining Bad Behavior Online . 10 The Role of Self-Awareness . 13 Self-Awareness and Mediated Communication . 15 Alternative Approaches To Anonymity . 18 The Non-Coordinatability of Traits and Percieved Anonymity . 18 The Online Sense of Unidentifiability . 20 Hypotheses . 23
Gastroscopy in Pediatric Surgery: Indications, Complications, Outcomes, and Ethical Aspects

Background. The aim of this study was to map gastroscopies performed at a single tertiary pediatric surgery centre to investigate indications, complications, outcomes, and ethical aspects. Material and Methods. A retrospective study of gastroscopies performed during two time periods (2001–2004 and 2011–2014) was conducted. Data regarding indications, outcomes, and complications of pediatric gastroscopies were analysed from a prospectively collected database. Results. The indications for gastroscopies changed over time. Therefore, 376 gastroscopies performed from 2011 through 2014 were studied separately. The median patient was four years old. The predominant indications were laparoscopic gastrostomy (40%), investigation of gastroenterological conditions (22%), obstruction in the upper gastrointestinal tract (20%), gastroesophageal reflux disease (GERD) (15%), and other indications (3%). Percentages of gastroscopies with no positive findings for each condition were laparoscopic gastrostomy, 100%; gastroenterological conditions, 46%; obstruction in the upper gastrointestinal tract, 36%; GERD, 51%. Furthermore, gastroscopies did not lead to any further action or change in treatment in 45% of gastroenterological conditions and 72% of GERD cases. The overall complication rate was 1%. Conclusion. The results are valuable to educate pediatric surgeons and to inform health care planning when including gastroscopy within clinical practice.
Effect of acute hyperglycemia on insulin secretion in humans.

First-phase insulin response to intravenous glucose is impaired both in type 2 diabetic patients and in subjects at risk for the disease. Hyperglycemia can modify beta-cell response by either inhibiting or potentiating both first- and second-phase insulin release. In normal subjects, the effect of acute hyperglycemia on insulin secretion is controversial. We measured (in 13 healthy volunteers) insulin secretion (by deconvolution of plasma C-peptide concentrations) during three consecutive 30-min hyperglycemic steps (2.8, 2.8, and 5.6 mmol/l), followed by an intravenous arginine bolus. First-phase insulin secretion in response to the first hyperglycemic step (456 +/- 83 pmol.min(-1). m(-2)) was significantly larger than that in response to the second step (311 +/- 37 pmol.min(-1). m(-2), P < 0.01); the subsequent increase in glycemia failed to stimulate first-phase secretion any further (377 +/- 60 pmol.min(-1). m(-2), NS vs. the previous value). This inhibition was also evident when insulin release rates were corrected for the respective increments (absolute or percentage) in plasma glucose levels and was not due to beta-cell exhaustion because the arginine bolus still elicited a large peak of insulin secretion (4,790 +/- 2,330 pmol.min(-1). m(-2)). In contrast, second-phase insulin secretion was related to the prevailing glucose levels across the three hyperglycemic steps in a direct quasilinear manner. We conclude that first-phase insulin secretion is inhibited by short-term modest hyperglycemia, whereas the second-phase insulin secretion increases linearly with hyperglycemia.
PixelNet: Towards a General Pixel-level Architecture

We explore architectures for general pixel-level prediction problems, from low-level edge detection to mid-level surface normal estimation to high-level semantic segmentation. Convolutional predictors, such as the fully-convolutional network (FCN), have achieved remarkable success by exploiting the spatial redundancy of neighboring pixels through convolutional processing. Though computationally efficient, we point out that such approaches are not statistically efficient during learning precisely because spatial redundancy limits the information learned from neighboring pixels. We demonstrate that (1) stratified sampling allows us to add diversity during batch updates and (2) sampled multi-scale features allow us to explore more nonlinear predictors (multiple fully-connected layers followed by ReLU) that improve overall accuracy. Finally, our objective is to show how a architecture can get performance better than (or comparable to) the architectures designed for a particular task. Interestingly, our single architecture produces state-of-the-art results for semantic segmentation on PASCAL-Context, surface normal estimation on NYUDv2 dataset, and edge detection on BSDS without contextual post-processing.
Student perspectives of online learning

The advent of online learning in tertiary education has changed the way students interact with institutions and undertake their studies. All students at Deakin University interact with their courses through an online learning environment. While online learning environments can be evaluated in a number of ways, the perceptions of the key users and their levels of satisfaction with the online learning environment are important measures. This paper presents results of a survey of students studying at Deakin University in 2005. The survey explored their perceptions of learning in the online environment. The results indicate that overall students were enthusiastic about learning in such an environment. The main advantages are the flexibility that it provides and the ability to study when it suits students. The disadvantages include technical issues such as speed of access, and the need to participate regularly. The size and spread of the responses suggest that these outcomes can be generalized for all students studying online.
Measuring participation of children with disabilities: Issues and challenges

Purpose. The aim of this paper is to examine conceptual issues that challenge development of valid and useful measures of children's participation. Method. Ambiguities in the current definition of participation in the International Classification of Functioning, Disability and Health (ICF) are examined along with their implications for developing valid measures for children and youth. Results. Developers of new measures must address three key issues that will affect the ultimate meaning of participation data obtained from these instruments: uncertain criteria to distinguish activity from participation; lack of consensus on whether measures should address objective or subjective aspects of participation or both; and appropriate choice of respondent when children are the focus. Variations in how the participation construct is operationalized challenge one's ability to develop a coherent body of knowledge about children's participation and the factors that influence it. Conclusion. Given current variations in how participation is being defined, both developers and users of measures of participation need to be explicit about the definition of participation that a particular measure represents and the inferences that can be drawn from the scores.
The Relationship between Extrinsic Motivation, Home Literacy, Classroom Instructional Practices, and Reading Proficiency in Second-Grade Chinese Children

R profi ciency is an important index of learning ability and is positively correlated with children’s academic achievement in elementary schools (Chapman et al., 2000). Consequently, educators are interested in investigating the various factors that promote early reading profi ciency, and various studies have shown that children’s reading motivation directly and indirectly infl uences their reading comprehension (Schraw et al., 1998; Wigfi eld and Guthrie, 1997a). Motivation can affect children’s commitment to reading, their approaches to reading, as well as their engagement in reading activities (Wang and Guthrie, 2004). For example, children will set higher goals for themselves and select more diffi cult books to read if they enjoy the subject of the books. Also, when readers are motivated to read, the amount of time they spend on reading is increased, and consequently their reading comprehension improves. A considerable number of studies have shown that parents and teachers play important roles in motivating and promoting early reading development (Baker, 2003; Wang and Guthrie, 2004). In the present study we examined how younger children’s extrinsic motivation and home literacy activities, parents’ participation in their children’s homework and teachers’ instructional practices were associated with children’s reading profi ciency.
Dupin Meshing: A Parameterization Approach to Planar Hex-Dominant Meshing

Planar hexagonal-dominant (PHex) meshes are an important class of meshes with minimal vertex-degree. They are highly useful in the rationalization of freeform architectural surfaces, for construction with flat steel, glass, or wooden panels of equal thickness. A PHex mesh must contain both convex and concave faces of varying anisotropic shapes due to the planarity constraint. Therefore, while parameterization-based approaches have been successfully used for planar-quad meshing, applying such approaches to PHex meshing has not been attempted so far. In this paper, we show how to bridge this gap, effectively allowing us to leverage the flexibility of quad-remeshing methods (e.g. field alignment, singularities) to PHex remeshing. We have two main observations. First, the anisotropy can be handled by isotropically remeshing a modified geometry, which we denote by curvature shape, and then pulling back the result to the original surface. Second, various non-convex face shapes can be generated robustly by locally modifying the grid texture used for discretizing the parametrization. Together, these reductions yield a simple and effective method for PHex remeshing of triangular surfaces, which is additionally robust, and applicable to a variety of models. We compare our method to recent state-ofthe-art methods for PHex meshing and demonstrate the advantages of our approach.
The Effects of Flexibility in Employee Skills, Employee Behaviors, and Human Resource Practices on Firm Performance

The components of human resource (HR) flexibility and their potential relationship to firm performance have not been empirically examined. The authors hypothesize that flexibility of employee skills, employee behaviors, and HR practices represent critical subdimensions of HR flexibility and are related to superior firm performance. Results based on perceptual measures of HR flexibility and accounting measures of firm performance support this prediction. Whereas skill, behavior, and HR practice flexibility are significantly associated with an index of firm financial performance, the authors find that only skill flexibility contributes to cost-efficiency.
Molecular mechanisms of Nrf2‐mediated antioxidant response

Nrf2 is the key transcription factor regulating the antioxidant response. Nrf2 signaling is repressed by Keap1 at basal condition and induced by oxidative stress. Keap1 is recently identified as a Cullin 3‐dependent substrate adaptor protein. A two‐sites binding “hinge & latch” model vividly depicts how Keap1 can efficiently present Nrf2 as substrate for ubiquitination. Oxidative perturbation can impede Keap1‐mediated Nrf2 ubiquitination but fail to disrupt Nrf2/Keap1 binding. Nrf2 per se is a redox‐sensitive transcription factor. A new Nrf2‐mediated redox signaling model is proposed based on these new discoveries. Free floating Nrf2 protein functions as a redox‐sensitive probe. Keap1 instead functions as a gate keeper to control the availability of Nrf2 probes and thus regulates the overall sensitivity of the redox signaling. © 2008 Wiley‐Liss, Inc.
The Influence of Text Annotation Tools on Print and Digital Reading Comprehension

Recent studies that compared reading comprehension between print and digital displays found a disadvantage for digital reading. A separate line of research has shown that effective use of learning strategies and active learning tools (e.g. annotation tools: highlighting, underlining and notetaking) can improve reading comprehension. Here, the influence of annotation tools on comprehension and their utility in diminishing the gap between print and digital reading was investigated. In a 2 X 2 experimental design, ninety three undergraduates (mean age 29.6 years, 72 women) read an academic essay in print or in digital format, with or without the use of annotation tools. In general, the results reinforce previous research reports on the inferiority of digital compared to print reading comprehension. Our findings indicate that for factual-level questions using annotation tools had no effect on comprehension in both formats. For the inference-level questions, however, use of annotation tools improved comprehension of printed text but not of digital text. In other words, text-annotation in the digital format had no effect on reading comprehension. In the digital era, digital reading is the norm rather than the exception; thus, it is essential to improve our understanding of the factors that influence the comprehension of digital text.
Estradiol-Induced Increase in the Magnitude of Long-Term Potentiation Is Prevented by Blocking NR2B-Containing Receptors

Estradiol, through activation of genomic estrogen receptors, induces changes in synaptic morphology and function in hippocampus, a brain region important for memory acquisition. Specifically, this hormone increases CA1 pyramidal cell dendritic spine density, NMDA receptor (NMDAR)-mediated transmission, and the magnitude of long-term potentiation (LTP) at CA3–CA1 synapses. We recently reported that the estradiol-induced increase in LTP magnitude occurs only when there is a simultaneous increase in the fractional contribution of NMDAR-mediated transmission relative to AMPA receptor transmission, suggesting a direct role for the increase in NMDAR transmission to the heightened LTP magnitude. Estradiol has been shown to increase expression of the NMDAR subunit NR2B, but whether this translates into an increase in function of NR2B-containing receptors remains to be determined. Here we show that not only is the estradiol-induced increase in NMDAR transmission mediated by NR2B-containing receptors, but blocking these receptors using RO25-6981 [R-(R,S)-α-(4-hydroxyphenyl)-β-methyl-4-(phenylmethyl)-1-piperidine propranol] (0.5 μm), an NR2B selective antagonist, prevents the estradiol-induced increase in LTP magnitude. Thus, our data show a causal link between the estradiol-induced increase in transmission mediated by NR2B-containing NMDARs and the increase in LTP magnitude.
Lucas' square pyramid problem revisited

are given by (s, t) = (1, 1) and (24, 70). Putative solutions by Moret-Blanc [30] and Lucas [25] contain fatal flaws (see e.g. [39] for details) and it was not until 1918 that Watson [39] was able to completely solve equation (1.1). His proof depends upon properties of elliptic functions of modulus 1/ √ 2 and arguably lacks the simplicity one might desire. A second, more algebraic proof was found in 1952 by Ljunggren [23], though it also is somewhat on the complicated side. Attempts to repair this perceived defect have, in recent years, resulted in a number of elementary proofs, by Ma [26] and [27], Cao and Yu [6], Cucurezeanu [10] and Anglin [2]. Various generalizations, distinct from that considered here, have been addressed in [12] and [33]. We rewrite equation (1.1) as s(s+ 1)(2s+ 1) 6 = t2