Miracle-dz/UniFAR-FTUs huggingface dataset:
Promoting Student Engagement in MOOCs

MOOCs offer valuable learning experiences to students from all around the world. In addition to providing filmed lectures, readings, and problem sets, many MOOCs allow students to ask and answer questions about course materials with each other through interactive user forums. However, in current MOOCs, only 3 to 5 percent of those students interact in the user forum (Breslow 2013, Rosé et al. 2014) and more than 90 percent of students stop attending the course altogether (Jordan 2014). According to prior studies, this low level of social engagement in MOOCs may lead to student attrition and low performance (Ren et al. 2007). Hence, a natural question that arises then is, how can we promote interaction among students in MOOC discussion forums in order to reduce students' attrition and raise their performance? In this paper, we conduct a field experiment on the edX platform to identify factors that promote student engagement in MOOC discussion forums. Researchers have discovered that the number of people interacting in one online location (e.g. group, community or virtual classroom size) is a key characteristic mediating user engagement (Butler et. al 2014), and most prior works have shown that users in a smaller size group participate more per person. However, contrary to prior research, our results show that the students in larger size cohorts interact more per person and that this greater interaction in turn increases student retention and performance.
A pseudopolynomial network flow formulation for exact knapsack separation

The NP-complete separation problem for the knapsack polyhedron is formulated as a side-constrained network flow problem with a pseudopolynomial number of vertices and edges. It is demonstrated that the primal polyhedron associated with this formulation can be projected onto an appropriate subspace to yield and that the dual polyhedron can be projected onto an appropriate subspace to yield the polar of . Practical consequences of the formulation are discussed.
Predictors of posttraumatic stress symptoms in childhood cancer survivors.

OBJECTIVE The diagnosis and treatment of childhood cancer are extremely stressful experiences, with psychological sequelae which can persist many years after the end of treatment. This study investigated the relative contributions of general anxiety, treatment intensity, medical sequelae of treatment, and the subjective appraisal of life threat and treatment intensity to later posttraumatic stress symptoms, such as intrusive memories, avoidance, and hypervigilance. METHOD One hundred eighty-six childhood cancer survivors ages 8 through 20 years, off of treatment for more than 1 year, and their parents completed questionnaires. Medical sequelae of treatment and intensity of treatment were rated by a pediatric oncologist. RESULTS Significant, independent predictors of persistent posttraumatic stress symptoms included: 1) the survivor's retrospective subjective appraisal of life threat at the time of treatment, and the degree to which the survivor experienced the treatment as "hard" or "scary"; 2) the child's general level of anxiety; 3) history of other stressful experiences; 4) time since the termination of treatment (negative association); 5) female gender; and 6) family and social support. Mother's perception of treatment and life threat contributed to anxiety and subjective appraisal for the survivor, but did not independently contribute to posttraumatic stress symptoms. CONCLUSIONS Symptoms of posttraumatic stress seem to decrease with time, but are persistent in a subset of childhood cancer survivors. Other than time and gender, the predictors of posttraumatic stress symptoms are primarily subjective factors (ie, anxiety and subjective appraisal) rather than objective stressors of treatment and medical sequelae.
Beyond Opinion Leaders

The number of Americans who report engaging in interpersonal persuasion during elections has drastically increased over the past decade. While past studies have demonstrated the impact of such proselytizing on vote choice, the author finds substantial evidence that it may also have larger democratic benefits, both for those attempting to persuade and for those whom they choose to target. Data from the 2008 National Annenberg Election Survey suggest that (a) attempting to persuade contributes to people’s ability to give reasons in support of both their own preferred candidate and the opposing candidate, and (b) persuasive conversation is a powerful channel for the spread of political information from the more engaged to the less engaged.
Social status and the pursuit of positive social identity: Systematic domains of intergroup differentiation and discrimination for high- and low-status groups

Research on intergroup discrimination has focused on the cognitive and motivational mechanisms involved, but the role of stereotype content has been neglected. Drawing on social identity theory and stereotype content research, the current studies investigated the role of stereotype content in intergroup differentiation and discrimination. Across two studies, students from high- and low-status groups differentiated themselves positively on stereotypes of competence and warmth respectively, and in allocations of resources in domains relevant to competence (academics, research) and warmth (sports, community outreach). Furthermore, there was evidence that discrimination by high- and low-status groups was driven by their respective stereotypes of competence and warmth. It is argued that stereotypes of competence and warmth, derived from status and power relations between groups, define the domains in which groups pursue positively distinct identities.
Efficiency-Oriented Optimal Design of the LLC Resonant Converter Based on Peak Gain Placement

The LLC resonant converter topology is widely used in dc-dc converter applications due to its advantages in achieving high efficiency and high power density. However, due to the complexity in the analysis, the converter lacks a clear design guideline on the selection of resonant tank parameters. In this paper, an optimization method is developed based on the operation mode analysis and peak gain placement. Following this approach, the converter can minimize the conduction loss while maintaining the required gain range. A 400-W, 400-V output and 25-38 V input LLC converter is built using the proposed method, which achieves above 98% peak efficiency. As a comparison, the conventional searching method is used to reselect the LLC parameters for the same specifications, and the experimental results show that the optimal design has better performance.
The safety of sublingual‐swallow immunotherapy: an analysis of published studies

Background As the main target of sublingual immunotherapy (SLIT) is to reduce at most the occurrence of adverse events (AE), safety represents a critical issue. This aspect deserves particular mention when a higher dose of allergen extract than traditional subcutaneous immunotherapy (SCIT) is required to be effective: that may be up to 500 times that employed for SCIT.
Ultrastructural Features and Expression of Cytoskeleton Proteins of Podocyte from Patients with Minimal Change Disease and Focal Segmental Glomerulosclerosis

Focal segmental glomerulosclerosis (FSGS) and minimal change disease (MCD) have been suggested for the category of podocytopathies. An ultrastructural observation and immunogold labeling for cytoskeleton proteins of podocytes on 11 cases each of FSGS and MCD were performed. Compared to MCD, more severe ultrastructural alterations of podocyte were identified in FSGS, which were characterized by higher frequency of mat-like condensation of microfilaments in the foot process and the detachment of the foot process from glomerular basement membrane. The labeling of α-actinin of podocytes in FSGS was significantly higher than MCD, which suggested an abnormal expression of cytoskeleton protein of podocyte in FSGS. The present study demonstrated a much more severe podocyte injury at the ultrastructural level in FSGS than in MCD.
Ceramide-induced and Age-associated Increase in Macrophage COX-2 Expression Is Mediated through Up-regulation of NF-κB Activity*

We have shown that the age-associated increase in lipopolysaccharide (LPS)-stimulated macrophages (Mφ) prostaglandin E2 (PGE2) production is because of ceramide-induced up-regulation of cyclooxygenase (COX)-2 transcription that leads to increased COX-2 expression and enzyme activity. To determine the mechanism of the age-related and ceramide-dependent increase in COX-2 transcription, we investigated the role of various transcription factors involved in COX-2 gene expression. The results showed that LPS-initiated activations of both consensus and COX-2-specific NF-κB, but not AP-1 and CREB, were significantly higher in Mφ from old mice than those from young mice. We further showed that the higher NF-κB activation in old Mφ was because of greater IκB degradation in the cytoplasm and p65 translocation to the nucleus. An IκB phosphorylation inhibitor, Bay 11-7082, inhibited NF-κB activation, as well as PGE2 production, COX activity, COX-2 protein, and mRNA expression in both young and old Mφ. Similar results were obtained by blocking NF-κB binding activity using a NF-κB decoy. Furthermore, NF-κB inhibition resulted in significantly greater reduction in PGE2 production and COX activity in old compared with young Mφ. Addition of ceramide to the young Mφ, in the presence or absence of LPS, increased NF-κB activation in parallel with PGE2 production. Bay 11-7082 or NF-κB decoy prevented this ceramide-induced increase in NF-κB binding activity and PGE2 production. These findings strongly suggest that the age-associated and ceramide-induced increase in COX-2 transcription is mediated through higher NF-κB activation, which is, in turn, because of a greater IκB degradation in old Mφ.
Hyperbaric oxygen therapy for severe acute pancreatitis

Despite improvements in the supportive management of severe acute pancreatitis over the last decade, the morbidity and mortality rate remains high. The main feature of this condition is pancreatic necrosis leading to sepsis, with both localized and systemic inflammatory response syndromes. Early pathophysiological changes of the pancreas include alterations in microcirculation, ischemia reperfusion injury, and leukocyte and cytokine activation. The efficacy of hyperbaric oxygen (HBO) therapy in improving these pathophysiological disturbances is documented for various conditions. However, its effect in the treatment of severe acute pancreatitis is undetermined. This report documents the case of a 56‐year‐old woman presenting with severe acute pancreatitis treated by HBO therapy. The severity of disease was based on an Acute Physiology and Chronic Health Evaluation (APACHE II) illness grading score of 11 and a Baltazar based computed tomography severity index (CTSI) score of 9. Administration of 100% oxygen was commenced within 72 h of presentation at a pressure of 2.5 atmospheres for 90 min and given twice daily for a total of 5 days. Therapy was well tolerated with improvements in APACHE II and CTSI grading scores. HBO therapy for severe acute pancreatitis appeared to be safe and may have a role in improving treatment outcomes. Further study is required.
Representation of concave distortions and applications

ABSTRACT A family of concave distortion functions is a set of concave and increasing functions, mapping the unity interval onto itself. Distortion functions play an important role defining coherent risk measures. We prove that any family of distortion functions which fulfils a certain translation equation, can be represented by a distribution function. An application can be found in actuarial science: moment-based premium principles are easy to understand but in general are not monotone and cannot be used to compare the riskiness of different insurance contracts with each other. Our representation theorem makes it possible to compare two insurance risks with each other consistent with a moment-based premium principle by defining an appropriate coherent risk measure.
Arabidopsis S 6 kinase mutants display chromosome instability and altered RBR 1 – E 2 F pathway activity

Rossana Henriques*, Zoltán Magyar, Antonia Monardes, Safina Khan, Christine Zalejski, Juan Orellana, László Szabados, Consuelo de la Torre, Csaba Koncz and László Bögre* Royal Holloway, University of London, School of Biological Sciences, Egham Hill, Egham, UK, Institute of Plant Biology, Biological Research Centre, Szeged, Hungary, Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu, Madrid, Spain, Unidad de Genética, Departamento de Biotecnologia, ETSI Agrónomos, Universidad Politécnica de Madrid, Spain and Max-Planck Institut für Züchtungforschung, Carl-von-Linné-Weg 10, Köln, Germany
Space charge behaviors of PP/POE/ZnO nanocomposites for HVDC cables

Polypropylene (PP) has been paid much attention due to its high melting point, excellent electrical insulting performance and thermoplastic property, which is potential to replace the XLPE as HVDC cable insulating material. Blending PP with polyolefin elastomer (POE) is an effective way to modify its stiffness and brittleness at room temperature. However, space charge behavior of PP/POE blend, as a great concern under dc stress, is not clear and needs further investigation. To research the space charge behaviors, pure PP, PP/POE blend and its nanocomposites with different contents were prepared. Then, mechanical properties, permittivity constant, breakdown strength, volume resistivity, space charge behaviors and trap level distribution were investigated. The results indicate the addition of POE enhances the mechanical flexibility of PP greatly, and nano-sized ZnO doping has little effect on the mechanical flexibility of PP/POE blend. The nanocomposites show lower permittivity constant, higher breakdown strength and higher volume resistivity than the PP/POE blend. Compared to pure PP, the space charge accumulation and electric field distortion get severe in PP/POE blend. However, by nanoparticles doping, space charges are remarkably suppressed, which is related to the increased trap level density in nanocomposites. It indicates the PP/POE/ZnO nanocomposites have much potential for HVDC cable application, which show high mechanical flexibility as well as excellent electrical performance.
Higher-order model checking with traversals

Higher-order recursion schemes are a powerful model of functional computation that grew out of traditional recursive program schemes and generalisations of grammars. It is common to view recursion schemes as generators of possibly-infinite trees, which Ong showed to have a decidable monadic second order theory and opened the door to applications in verification. Kobayashi later presented an intersection type characterisation of the model checking problem, on which most subsequent applied work is based. In recent work, recursion schemes have been considered to play a role similar to Boolean programs in verification of first-order imperative programs: a natural target for abstraction of programs with very large or infinite data domains. In this thesis we focus on the development of model checking algorithms for variants of recursion schemes. We start our contributions with a model checking algorithm inspired by the fully abstract game semantics of recursion schemes, but specified as a goal-directed approach to intersection type inference, that offers a unification of the views of Ong and Kobayashi. We build on this largely theoretical contribution with two orthogonal extensions and practical implementations. First, we develop a new extension of recursion schemes: higher-order recursion schemes with cases, which add non-determinism and a case construct operating over a finite data domain. These additions provide us with a more natural and succinct target for abstraction from functional programs: encoding data using functions inevitably results in an increase in the order and arity of the scheme, which have a direct impact on the worst-case complexity of the problem. We characterise the model checking problem using a novel intersection and union type system and give a practical algorithm for type inference in this system. We have carried out an empirical evaluation of the implementation --- the tool TRAVMC --- using a variety of problem instances from the literature and a new suite of problem instances derived via an abstraction-refinement procedure from functional programs. Second, we extend our approach from safety properties to all properties expressible in monadic second order logic using alternating parity tree automata as our specification language. We again provide an implementation and an empirical evaluation, which shows that despite the challenges accompanying liveness properties our tool scales beyond the current state of the art.
HIV testing, HIV infection and associated risk factors among inmates in south-eastern French prisons

Objectives:To estimate HIV seroprevalence in the two main remand and short-stay prisons of south-eastern France and to gather linked anonymous risk-factor information. Setting:Baumettes prison, Marseille, France between 16 November and 21 December 1992. Participants:Using a self-administered questionnaire about HIV testing and risk factors for HIV infection, 295 male and 137 female inmates were interviewed. The response rate was 96% (100 and 90% for men and women, respectively). At the same time, 279 of a total of 432 (65%) inmates were serologically tested for HIV; 153 (35%) declined to provide a blood sample. Design:Anonymous cross-sectional and surveillance survey. Results:Twenty per cent of participants (84 out of 432) were intravenous drug (heroin) users (IVDU), 51% of whom reported needle-sharing prior to incarceration; 23% reported more than two sexual partners during the last year, and 13% sexual intercourse with an IVDU during the last 5 years. HIV status was available for 356 inmates (82%; 65% from blood samples and 17% from the questionnaire); 39 were HIV-infected (10.9%; 95% confidence interval, 7.7–14.2). The inmates not tested for HIV reported proportionally less risky behaviours than non-HIV-infected inmates. HIV seroprevalence was significantly higher among recidivist inmates (19.9 versus 4.4%; P<0.0001). The rate of HIV infection was particularly high among IVDU (34 out of 84; 40%). More female non-IVDU were HIV-infected than male non-IVDU (4.1 versus 0.6%; P=0.04). Conclusions:This study demonstrates the high prevalence of HIV infection in south-eastern French prisons, especially among IVDU. The rates may be related to the high prevalence of risky drug practices and to delays in the development of HIV prevention programmes for IVDU in France. The higher seroprevalence rate among recidivist inmates might be the result of risk behaviours during imprisonment. Another hypothesis is that recidivist inmates are at greater risk of HIV infection because of higher levels of drug use.
Influence of stress on the secretion of corticosterone in the duck (Anas platyrhynchos).

The influence of stress on the secretion of corticosterone has been investigated by radioimmunoassay in domestic ducks (Anas platyrhynchos) of 6-8 weeks of age. Intravenous and i.m. injections of synthetic ACTH (Synacthen, 25 i.u./bird and Synacthen Depot, 100 i.u./bird respectively) markedly increased (2.7- to 10-fold) basal concentrations of corticosterone in plasma (3-6 ng/ml) in comparison with those in birds injected with 0.9% saline (1 ml/bird). Maximum levels of 30-40 ng/ml plasma were reached after 30 min and 5 h respectivley. Increased levels of corticosterone in plasma were also seen within 5 min of i.v. administration of saline and remained as high as those in birds treated with Synacthen for at least 20 min after injection. Blood sampling (from the brachial vein) was, by itself, sufficient to increase levels of corticosterone in plasma; a large (twofold) rise being observed as soon as 1 min after initial handling and bleeding, with concentrations of 30-40 ng/ml being found in birds bled 15 times during a period of 14 min. However, in a flock of birds, the alarm created in unhandled birds while others were being bled had no effect on concentrations of corticosterone in plasma. Deprivation of food or water for 24 h also enhanced levels of corticosterone in plasma, as did 24 h of adaptation to 0.2 M-NaCl drinking water. These results have demonstrated the lability of the secretion of corticosterone in response to stress and demonstrated its usefulness as a physiological indicator of stress in ducks.
How Learners’ Interactions Sustain Engagement: A MOOC Case Study

In 2015, 35 million learners participated online in 4,200 MOOCs organized by over 500 universities. Learning designers orchestrate MOOC content to engage learners at scale and retain interest by carefully mixing videos, lectures, readings, quizzes, and discussions. Universally, far fewer people actually participate in MOOCs than originally sign up with a steady attrition as courses progress. Studies have correlated social engagement to completion rates. The FutureLearn MOOC platform specifically provides opportunities to share opinions and to reflect by posting comments, replying, or following discussion threads. This paper investigates learners’ social behaviors in MOOCs and the impact of engagement on course completion. A preliminary study suggested that dropout rates will be lower when learners engage in repeated and frequent social interactions. We subsequently reviewed the literature of prediction models and applied social network analysis techniques to characterize participants’ online interactions examining implications for participant achievements. We analyzed discussions in an eight week FutureLearn MOOC, with 9,855 enrolled learners. Findings indicate that if a learner starts following someone, the probability of their finishing the course is increased; if learners also interact with those they follow, they are highly likely to complete, both important factors to add to the prediction of completion model.
Expression of matrix metalloproteinase-9 (MMP-9) and blood vessel density in laryngeal squamous cell carcinomas

Abstract Conclusion: In this study we found that inflammatory cells may be a source of MMP-9 in laryngeal cancer. MMP-9 was correlated with blood vessel density. MMP-9 may be a potential target to disrupt tumor neovascularization. Objective: To study the expression of MMP-9 in laryngeal cancer and determine a possible relation with blood vessel density. Methods: Immunohistochemistry was used for MMP analysis and for blood vessel detection in 83 laryngeal cancer samples. The density of blood vessels was analyzed with a stereological tool. Results: MMP-9 was detected in inflammatory cells. Positivity for MMP-9 correlated significantly with the grade of differentiation (p = 0.025). Expression of MMP-9 was not correlated with T stage, nodal metastasis, or tumor recurrence. The mean blood vessel density was 51.4 vessels/mm2. Specimens were more likely to exhibit higher density of blood vessels when MMP-9 expression was also present (p = 0.014).
Taxanes as primary chemotherapy for early breast cancer

In patients with locally advanced and operable breast cancer, neoadjuvant chemotherapy has been demonstrated to increase the chance of breast‐conserving surgery (BCS) when compared with adjuvant treatment; moreover, patients who achieve a pathologic complete response (pCR) have a better outcome. A literature‐based meta‐analysis of randomized clinical trials (RCTs) to ‘weigh’ how much taxanes add to anthracyclines as primary treatment over standard chemotherapy was conducted.