Miracle-dz/UniFAR-FTUs huggingface dataset:
Model-Based Collaborative Filtering Analysis of Student Response Data: Machine-Learning Item Response Theory

We apply collaborative filtering (CF) to dichotomously scored student response data (right, wrong, or no interaction), finding optimal parameters for each student and item based on cross-validated prediction accuracy. The approach is naturally suited to comparing different models, both unidimensional and multidimensional in ability, including a widely used subset of Item Response Theory (IRT) models which obtain as specific instances of the CF: the one-parameter logistic (Rasch) model, Birnbaum’s 2PL model, and Reckase’s multidimensional generalization M2PL. We find that IRT models perform well relative to generalized alternatives, and thus this method offers a fast and stable alternate approach to IRT parameter estimation. Using both real and simulated data we examine cases where oneor two-dimensional IRT models prevail and are not improved by increasing the number of features. Model selection is based on prediction accuracy of the CF, though it is shown to be consistent with factor analysis. In multidimensional cases the item parameterizations can be used in conjunction with cluster analysis to identify groups of items which measure different ability dimensions.
Spontaneous Discrimination

This paper considers a dynamic economy in which agents are repeatedly matched with one another and decide whether to enter into profitable partnerships. Each agent has a physical colour and a social colour. The social colour of an agent acts as a signal about the physical colour of agents in his partnership history. Before an agent makes a decision, he observes his match's physical and social colours. Neither the physical colour nor the social colour is payoff-relevant. We identify environments where, in some equilibria, agents condition their decisions on the physical and social colours of their potential partners. That is, they discriminate. The main result of the paper is that, in these aforementioned environments, every stable equilibrium must involve discrimination. In particular, the colour-blind equilibrium is unstable.
Network-layer fairness for adaptive video streams

Recent studies observe that competing adaptive video streaming applications generate flows that lead to instability, under-utilization, and unfairness in bottleneck link sharing within the network. Additional measurements suggest there may also be a negative impact on users' perceived quality of service as a consequence. While it may be intuitive to resolve application-generated issues at the application layer, in this paper we explore the merits of a network layer solution. We are motivated by the observation that traditional network-layer metrics associated with throughput, loss, and delay are inadequate to the task. To bridge this gap we present a network-layer QoS framework for adaptive streaming video fairness that reflect the video user's quality of experience (QoE). We begin first by deriving a new measure to describe user-level fairness among competing flows, one that reflects the dynamics between the video encoding and its mapping to a screen with a given size and resolution. We then design and implement our framework in VHS (Video-Home-Shaper) to evaluate performance in the home's last access hop where this problem is known to exist. Experiments using a variety of devices, O/S platforms, and viewing screens demonstrate the merits of using video QoE as a basis for fair bandwidth sharing.
Incidence and Risk Factors for Respiratory Syncytial Virus and Human Metapneumovirus Infections among Children in the Remote Highlands of Peru

Introduction The disease burden and risk factors for respiratory syncytial virus (RSV) and human metapneumovirus (MPV) infections among children living in remote, rural areas remain unclear. Materials and Methods We conducted a prospective, household-based cohort study of children aged <3 years living in remote rural highland communities in San Marcos, Cajamarca, Peru. Acute respiratory illnesses (ARI), including lower respiratory tract infection (LRTI), were monitored through weekly household visits from March 2009 through September 2011. Nasal swabs collected during ARI/LRTI were tested for RSV, MPV, and other respiratory viruses using real-time RT-PCR. Incidence rates and rate ratios were calculated using mixed effects Poisson regression. Results Among 892 enrolled children, incidence rates of RSV and MPV ARI were 30 and 17 episodes per 100 child-years, respectively. The proportions of RSV and MPV ARI that presented as LRTI were 12.5% and 8.9%, respectively. Clinic visits for ARI and hospitalizations were significantly more frequent (all p values <0.05) among children with RSV (clinic 41% and hospital 5.3%) and MPV ARI (38% and 3.5%) when compared with other viral infections (23% and 0.7%) and infections without virus detected (24% and 0.6%). In multivariable analysis, risk factors for RSV detection included younger age (RR 1.02, 95% CI: 1.00-1.03), the presence of a smoker in the house (RR 1.63, 95% CI: 1.12-2.38), residing at higher altitudes (RR 1.93, 95% CI: 1.25-3.00 for 2nd compared to 1st quartile residents; RR 1.98, 95% CI: 1.26-3.13 for 3rd compared to 1st quartile residents). Having an unemployed household head was significantly associated with MPV risk (RR 2.11, 95% CI: 1.12-4.01). Conclusion In rural high altitude communities in Peru, childhood ARI due to RSV or MPV were common and associated with higher morbidity than ARI due to other viruses or with no viral detections. The risk factors identified in this study may be considered for interventional studies to control infections by these viruses among young children from developing countries.
Relation between Body Structure and Hearing during Soft Tissue Auditory Stimulation

Hearing is elicited by applying the clinical bone vibrator to soft tissue sites on the head, neck, and thorax. Two mapping experiments were conducted in normal hearing subjects differing in body build: determination of the lowest soft tissue stimulation site at which a 60 dB SL tone at 2.0 kHz was effective in eliciting auditory sensation and assessment of actual thresholds along the midline of the head, neck, and back. In males, a lower site for hearing on the back was strongly correlated with a leaner body build. A correlation was not found in females. In both groups, thresholds on the head were lower, and they were higher on the back, with a transition along the neck. This relation between the soft tissue stimulation site and hearing sensation is likely due to the different distribution of soft tissues in various parts of the body.
Cognitive Bias Modification Using Mental Imagery for Depression: Developing a Novel Computerized Intervention to Change Negative Thinking Styles

Why do some people see their glass as half–empty rather than half–full or even imagine that the glass will be filled in the future? Experimental methods can illuminate how individual differences in information processing style can profoundly impact mood or even result in disorders such as depression. A computerized cognitive bias modification intervention targeting interpretation bias in depression via positive mental imagery (CBM–I) was evaluated by investigating its impact on mental health and cognitive bias compared with a control condition. Twenty–six depressed individuals completed either positive imagery–focussed CBM–I or a control condition daily at home over one week. Outcome measures were collected pre–treatment and post–treatment and at two–week follow–up. Individuals in the positive condition demonstrated significant improvements from pre–treatment to post–treatment in depressive symptoms, cognitive bias and intrusive symptoms compared with the control condition. Improvements in depressive symptoms at two–week follow–up were at trend level. The results of this first controlled comparison of positive imagery–focussed CBM–I for depression further support the clinical potential of CBM–I and the development of a novel computerized treatment that could help patients imagine a more positive future. Broader implications concern the modification of individual differences in personality variables via their interaction with key information processing targets. Copyright © 2011 John Wiley & Sons, Ltd.
Structural and Statistical Approaches to Estimating Output Gap: First Attempt on Pakistan

The objective of this study is to estimate potential output vis-a-vis output gap for Pakistan's economy. This paper reviews six commonly used techniques to estimate potential output and from that the output gap. The results suggest that while measures of output gap are not identical they nonetheless do show some degree of association among each other. Therefore, a composite output gap is calculated for 1950 to 2007. The composite output gap depicts that Pakistan economy has been observing a cyclical episode of excess supply corresponding with demand pressures in the period of analysis. Furthermore, evidence suggests that Pakistan economy is currently experiencing rising demand pressures since FY05. Furthermore, these demand pressures show a high degree of correlation with the rising inflation as shown in the temporal correlation between inflation and composite of output gap measures.
On Borders and the Liminality of Undocumented Zimbabwean Migrants in South Africa

Abstract The historical continuities of the Zimbabwe–South Africa crossborder migrations provide a context in which such movements have continued, despite securitized borders, in post-apartheid South Africa. Based on a qualitative study of undocumented Zimbabwean migrants in three places; namely, the Beitbridge border, South African border town of Musina and the city of Johannesburg, between December 2014 and March 2015, I argue that, securitizing the border between South Africa and Zimbabwe leads to human smuggling, which places smuggled migrants in liminality and marginality, which in turn militates against the goal of free human mobility in the Southern African Development Community (SADC).
DWC2: A dynamic weight-based cooperative caching scheme for object-based storage cluster

Object-based storage is emerging as a next generation of distributed storage technology. Aiming at improving the performance and load-balancing of large-scale object-based storage system, we present a dynamic weight-based cooperative caching scheme referred to as DWC2, which allows an object-based storage device (OSD) to use the available free cache of the neighbouring OSD. Our proposed DWC2 replaces objects based on their weights which is a function of object size, popularity and replica number, and dynamically partitions the memory of OSD into local cache and remote cache according to activity workload. An object data is cached in local cache or remote cache of the cooperative OSDs, thus increasing cache hit ratio, reducing expensive disk access time as well as improving load balance. We benchmarked our proposed DWC2 with existing cooperative caching schemes under various OSD environments. Our rigorous experiment results conclusively demonstrate that our DWC2 is scalable and can achieve a significant cache hit ratio, average response time, and load balancing for large-scale OSD cluster.
Control over Money in Marriage

The basic question addressed in this chapter is “Who gets what in a marriage? ” I begin with the observation that any marriage involves two individuals, each of whom has their own experience of that marriage. The focus is on the economic outcomes experienced by each partner, and the influences on those outcomes. Which partner has greater control over the family’s finances? Which partner’s preferences are represented in family consumption decisions? Much of the current research on this issue, which uses family expenditure data, encounters a severe limitation: there are very few consumption items which can unambiguously be assigned to men, women or children. This paper answers the question “who gets what? ” in a novel way. I use data on how families manage their finances, to find out who has access to, who manages and who controls the family finances. I also explore the determinants of financial control. Does an improvement in one spouse’s bargaining position lead to greater control over money, or is control over money simply party of the couple’s division of labor? The study is based on a new a survey of families with children in the Ottawa-Hull area carried out by the author. The paper begins with a survey of recent developments in the study of intra-household resource allocation. What do we know about how resources are allocated inside households? What do we know about why the pattern of household resources is as it is? I then go on to describe the data set used in the research, and the main empirical findings. I do not find a systematic pro-male or pro-female bias in household finances. However I do find that, as predicted by theory, partners with greater incomes have greater control over money, younger spouses do better, and there is less income pooling when one partner, especially the man, has been married before.
HIF-1α knockdown by miRNA decreases survivin expression and inhibits A549 cell growth in vitro and in vivo

The present study examined the downregulation of survivin expression by hypoxia-inducible factor-1α (HIF-1α) miRNA and its effect in the inhibition of A549 cell growth in vitro and in vivo. Survivin expression, apoptosis, proliferation and migration under normoxic and hypoxic conditions were assessed by standard methods. Cotransfection and chromatin immunoprecipitation were used to observe the effects of HIF-1α on survivin transcription. HIF-1α knockdown in A549 cells were injected into nude mice to examine survivin expression and suppression of tumorigenicity. Transfection of A549 cells with HIF-1α miRNA led to decreased expression of HIF-1α and survivin mRNA and protein. Survivin overexpression is mediated by HIF-1α by direct binding to a putative binding site in the survivin core promoter. HIF-1α-miRNA induced apoptosis and inhibited proliferation of A549 cells under hypoxic, but not normoxic, conditions, whereas transfection by survivin expression vectors partly rescued the apoptotic phenotype and revived cell proliferation under hypoxic conditions. However, cell migration was substantially suppressed by HIF-1α silencing under normoxic and hypoxic conditions. After A549 cells were xenografted in nude mice, survivin expression in mice treated with HIF-1α miRNA was downregulated, and tumor growth was significantly inhibited. Silenced HIF-1α gene expression induced apoptosis and suppressed growth of A549 cells by downregulating survivin expression in vitro and in vivo. Our results also provide a basis to target the HIF-1α pathway in lung cancer therapy.
The structure of the CstF-77 homodimer provides insights into CstF assembly

The cleavage stimulation factor (CstF) is essential for the first step of poly(A) tail formation at the 3' ends of mRNAs. This heterotrimeric complex is built around the 77-kDa protein bridging both CstF-64 and CstF-50 subunits. We have solved the crystal structure of the 77-kDa protein from Encephalitozoon cuniculi at a resolution of 2 Å. The structure folds around 11 Half-a-TPR repeats defining two domains. The crystal structure reveals a tight homodimer exposing phylogenetically conserved areas for interaction with protein partners. Mapping experiments identify the C-terminal region of Rna14p, the yeast counterpart of CstF-77, as the docking domain for Rna15p, the yeast CstF-64 homologue.
A Multiobjective Evolutionary Approach to Concurrently Learn Rule and Data Bases of Linguistic Fuzzy-Rule-Based Systems

In this paper, we propose the use of a multiobjective evolutionary approach to generate a set of linguistic fuzzy-rule-based systems with different tradeoffs between accuracy and interpretability in regression problems. Accuracy and interpretability are measured in terms of approximation error and rule base (RB) complexity, respectively. The proposed approach is based on concurrently learning RBs and parameters of the membership functions of the associated linguistic labels. To manage the size of the search space, we have integrated the linguistic two-tuple representation model, which allows the symbolic translation of a label by only considering one parameter, with an efficient modification of the well known (2 + 2) Pareto archived evolution strategy (PAES). We tested our approach on nine real world datasets of different sizes and with different numbers of variables. Besides the (2 + 2)PAES, we have also used the well known nondominated sorting genetic algorithm (NSGA-II) and an accuracy-driven single-objective evolutionary algorithm (EA). We employed these optimization techniques both to concurrently learn rules and parameters and to learn only rules. We compared the different approaches by applying a nonparametric statistical test for pairwise comparisons, thus taking into consideration three representative points from the obtained Pareto fronts in the case of the multiobjective EAs. Finally, a data complexity measure, which is typically used in pattern recognition to evaluate the data density in terms of average number of patterns per variable, has been introduced to characterize regression problems. Results confirm the effectiveness of our approach, particularly for (possibly high dimensional) datasets with high values of the complexity metric.
Accelerated lifetime testing methodology for lifetime estimation of Lithium-ion batteries used in augmented wind power plants

The development of lifetime estimation models for Lithium-ion battery cells, which are working under highly variable mission profiles characteristic for wind power plant applications, requires a lot of expenditures and time resources. Therefore, batteries have to be tested under accelerated lifetime ageing conditions. This paper presents a three-stage methodology used for accelerated lifetime testing of Lithiumion batteries. The results obtained at the end of the accelerated ageing process can be used for the parameterization of a performance-degradation lifetime model. In the proposed methodology both calendar and cycling lifetime tests are considered since both components are influencing the lifetime of Lithium-ion batteries. The methodology proposes also a lifetime model verification stage, where Lithium-ion battery cells are tested at normal operating conditions using an application specific mission profile.
Codes, pedagogy and knowledge: Advances in Bernsteinian sociology of education

The intractability of working-class failure has remained an unresolved issue for the sociology of education over the last forty years. Although some inroads have been made in understanding how inequality is engendered through schooling (and through pedagogy in particular), in ongoing developments in curriculum policy globally, knowledge, or ‘the what’ of schooling, is perennially left out, even as global achievement comparisons such as TIMSS and PIRLS (Progress in International Reading and Literacy Study) highlight its salience. The policy trend towards expressing the objects of learning in generic, outcomes or skills-based terms in curricula systematically avoids an engagement with knowledge. Curriculum studies and sociology of education in the twenty-first century cannot continue to avoid interrogating what children know and don’t know. Thus far, it has been silent on the issue. In what follows, we offer a broad outline of the development of the sociological theory of Basil Bernstein, explaining how the development of his ideas across a period of forty years has progressively generated theoretical resources to explore not just how students learn, but what they learn. This theory has brought the question of the what and the how of teaching and learning to the forefront. In this way, Bernstein’s theory offers a theoretically informed approach to the awkward question of the intractability of unequal schooling outcomes.
Pycnogenol attenuates the symptoms of immune dysfunction through restoring a cellular antioxidant status in low micronutrient-induced immune deficient mice

BACKGROUND/OBJECTIVES We investigated the effect of Pycnogenol (Pyc) on survival and immune dysfunction of C57BL/6 mice induced by low micronutrient supplementation. MATERIALS/METHODS Female C57/BL/6 mice were fed a diet containing 7.5% of the recommended amount of micronutrients for a period of 12 wks (immunological assay) and 18 wks (survival test). For immunological assay, lymphocyte proliferation, cytokine regulation, and hepatic oxidative status were determined. RESLUTS Pyc supplementation with 50 and 100 mg·kg-1·bw·d-1 resulted in partial extension of the median survival time. Pyc supplementation led to increased T and B cell response against mitogens and recovery of an abnormal shift of cytokine pattern designated by the decreased secretion of Th1 cytokine and increased secretion of Th2 cytokine. Hepatic vitamin E level was significantly decreased by micronutrient deficiency, in accordance with increased hepatic lipid peroxidation level. However, Pyc supplementation resulted in a dose-dependent reduction of hepatic lipid peroxidation, which may result from restoration of hepatic vitamin E level. CONCLUSION Findings of this study suggest that Pyc supplementation ameliorates premature death by restoring immune dysfunction, such as increasing lymphocyte proliferation and regulation of cytokine release from helper T cells, which may result from the antioxidative ability of Pyc.
Efficient Minimum-Cost Bandwidth-Constrained Routing in Wireless Sensor Networks

A critical issue in the design of routing protocols for wireless sensor networks is the efficient utilization of resources such as scarce bandwidth and limited energy supply. Many routing schemes proposed in the literature try to minimize the energy consumed in routing or maximize the lifetime of the sensor network without taking into consideration limited bandwidth of wireless links. This can lead to congestion, increased delay, packet losses and ultimately to retransmission of packets, which will waste considerable amount of energy. This paper presents a routing protocol, which minimizes the total cost of routing while guaranteeing that the load on each wireless link does not exceed its capacity. The protocol is derived from a combinatorial optimization problem, known as the minimum-cost flow problem in the operations research literature. Because we use polynomialtime minimum-cost flow algorithms, the protocol is highly scalable. The proposed protocol is compared with the maximum lifetime bandwidth constrained routing protocol [1] (formulated as an Integer Linear Program). Simulation results indicate that the proposed protocol achieves longer lifetimes, delivers more number of messages and has higher residual energy than the maximum lifetime bandwidth constrained routing protocol for the test example.
Dimensions of coping in entrepreneurs: Functional and temporal perspectives and implications for burnout

The research comprised a two-phased mixed-methods investigation of functional and temporal dimensions of coping in entrepreneurs and implications for burnout. The research advances understanding of the stress-coping-strain relationship in entrepreneurs by establishing that temporal-dimensions of coping, and entrepreneurial traits have implications for burnout. Specifically, that entrepreneurs may benefit from reducing internal-focused coping in favour of external-focused coping, and from relinquishing negative views of the present, and focusing on achieving future goals.