Miracle-dz/UniFAR-FTUs huggingface dataset:
Variable selection in a flexible parametric mixture cure model with interval‐censored data

In standard survival analysis, it is generally assumed that every individual will experience someday the event of interest. However, this is not always the case, as some individuals may not be susceptible to this event. Also, in medical studies, it is frequent that patients come to scheduled interviews and that the time to the event is only known to occur between two visits. That is, the data are interval‐censored with a cure fraction. Variable selection in such a setting is of outstanding interest. Covariates impacting the survival are not necessarily the same as those impacting the probability to experience the event. The objective of this paper is to develop a parametric but flexible statistical model to analyze data that are interval‐censored and include a fraction of cured individuals when the number of potential covariates may be large. We use the parametric mixture cure model with an accelerated failure time regression model for the survival, along with the extended generalized gamma for the error term. To overcome the issue of non‐stable and non‐continuous variable selection procedures, we extend the adaptive LASSO to our model. By means of simulation studies, we show good performance of our method and discuss the behavior of estimates with varying cure and censoring proportion. Lastly, our proposed method is illustrated with a real dataset studying the time until conversion to mild cognitive impairment, a possible precursor of Alzheimer's disease. © 2015 The Authors. Statistics in Medicine Published by John Wiley & Sons Ltd.
Teaching and learning using case studies: a teaching note

This paper reviews the use of the case method as a teaching and learning vehicle. It centres on a module that aims to develop learning by the use of the case method. It examines the rationale for the development of the module and the subsequent decision to use the case method. Also identified in the paper are issues concerned with module operation and assessment. Finally, an attempt is made to evaluate the module based on a student experience perspective.
Online globally consistent mosaicing using an efficient representation

This work addresses the problem of mosaic construction from image sequences. We propose an incremental, globally consistent method in which each new frame of the sequence is aligned to the mosaic that has been constructed up to that time instant. We propose an efficient, stochastic mosaic representation, in which the color of each pixel is represented with a mixture of Gaussians. The parameters of the Gaussian mixture are learned on-the-fly. The proposed method is particularly suited for long image sequences, since it prevents accumulation of small alignment errors and maintains constant memory requirements. Results for synthetic and real image sequences are presented.
Video denoising based on matrix recovery with total variation priori

This article presents a novel scheme for video denoising based on improved matrix recovery strategy. The proposed scheme attempts to go beyond the conventional approaches that focus on the rank properties of the matrix by making use of a priori knowledge derived from the characteristics of video and noise. In this paper, we will first demonstrate that the conventional approach such as robust PCA (principal component analysis) is not effective when the video is corrupted by the mixture of impulse and Gaussian noises. The impulse noise can be considered sparse in the image domain and can be effectively filtered by matrix recovery. However, the dense Gaussian noise cannot be easily filtered because it is not sparse in either spatial or frequency domain. We shall show that this Gaussian noise corrupted video can be considered sparse in the 3D total variation domain. Based on this, we formulate the problem as a 3D total variation optimization and design an algorithm to solve this convex problem efficiently. Experimental results show that the proposed scheme achieves noticeable improvement over the state-of-the-art algorithm VBM3D [5].
Geolocalized Modeling for Dish Recognition

Food-related photos have become increasingly popular , due to social networks, food recommendations, and dietary assessment systems. Reliable annotation is essential in those systems, but unconstrained automatic food recognition is still not accurate enough. Most works focus on exploiting only the visual content while ignoring the context. To address this limitation, in this paper we explore leveraging geolocation and external information about restaurants to simplify the classification problem. We propose a framework incorporating discriminative classification in geolocalized settings and introduce the concept of geolocalized models, which, in our scenario, are trained locally at each restaurant location. In particular, we propose two strategies to implement this framework: geolocalized voting and combinations of bundled classifiers. Both models show promising performance, and the later is particularly efficient and scalable. We collected a restaurant-oriented food dataset with food images, dish tags, and restaurant-level information, such as the menu and geolocation. Experiments on this dataset show that exploiting geolocation improves around 30% the recognition performance, and geolocalized models contribute with an additional 3-8% absolute gain, while they can be trained up to five times faster.
The Development of Sensitivity to Sublexical Orthographic Constraints: An Investigation of Positional Frequency and Consistency Using a Wordlikeness Choice Task

The developmental sequence of the types of orthographic knowledge that children acquire early in reading development is unclear. Following findings of skilled reading, the orthographic constraints of positional frequency and feedback consistency were explored with a wordlikeness judgement task for grades 1–3 English-speaking children. The data provide evidence for the early development of sensitivity to positional frequency, but not sound-spelling consistency. However, sensitivity to each type of orthographic structure was predicted by rapid naming and sensitivity to consistency was predicted by phonological awareness. As well, sensitivity to each type of constraint was related to word reading fluency.
Scalable view expansion in a peer mediator system

To integrate many data sources we use a peer mediator-framework where views defined in the peers are logically composed in terms of each other A common approach to execute queries over mediators is to treat views in data sources as 'black boxes'. The mediators locally decompose queries into query fragments and submit them to the data sources for processing. Another approach, used in distributed DBMSs, is to treat the views as 'transparent boxes' by importing and fully expanding all views and merge them with the query. The black box approach often leads to inefficient query plans. However, in a peer mediator framework full view expansion (VE) leads to prohibitively long query compilation times when many peers are involved. It also limits peer autonomy since peers must reveal their view definitions. We investigate in a peer mediator framework the tradeoffs between none, partial, and full VE in two different distributed view composition scenarios. We show that it is often favorable with respect to query execution and sometimes even with respect to query compilation time to expand those views having common hidden peer subviews. However, in other cases it is better to use the 'black box' approach, in particular when peer autonomy prohibits view importation. Based on this, a hybrid strategy for VE in peer mediators is proposed.
Small Moving Target Detection based on the Concept of Entropy Flow

The detection of small moving targets under motorial background is very difficult. In order to solve this issue, a novel detection algorithm is presented in this paper, which is based on the concept of entropy flow. Firstly, the concept of entropy flow is used to measure image motion; Secondly, 2-dimensional histogram of flow field is applied to estimate the background motion; Finally, the targets are obtained by using pipeline filtering in difference image. The experiment results demonstrate that the proposed algorithm is appropriate to detect small targets under moving backgrounds, and the algorithm provides an instructive approach to the detection of small targets.
Dual Enrollment Variables and College Student Persistence

In the knowledge economy, now more than ever, students are encouraged to attend an institution of higher education. Students actively search for resources to assist them in their progress toward a college degree, even before high school graduation. Dual enrollment is an opportunity for students to complete college courses while still in high school, and it encourages stronger collaborations between K–12 and higher education. The purpose of this study was to explore the relationship between demographic and policy variables in South Carolina technical college dual enrollment programs and first-to-second-year persistence of dually enrolled students once entering college. All participants in this study were high school students who continued at a technical college after graduation. Outcomes were analyzed using logistic regression to determine persistence, defined as first-to-second-year retention. Variables included dual enrollment course type, course setting, ethnicity, gender, and county of residence. Results show that course type and course setting are significant in predicting college student persistence. Recommendations and implications for future research are discussed.
Haptic Augmented Reality: Taxonomy and an Example of Stiffness Modulation

Haptic augmented reality (AR) enables the user to feel a real environment augmented with synthetic haptic stimuli. This article addresses two important topics in haptic AR. First, a new taxonomy for haptic AR is established based on a composite visuo-haptic reality-virtuality continuum extended from the conventional continuum for visual AR. Previous studies related to haptic AR are reviewed and classified using the composite continuum, and associated research issues are discussed. Second, the feasibility of haptically modulating the feel of a real object with the aid of virtual force feedback is investigated, with the stiffness as a goal haptic property. All required algorithms for contact detection, stiffness modulation, and force control are developed, and their individual performances are thoroughly evaluated. The resulting haptic AR system is also assessed in a psychophysical experiment, demonstrating its competent perceptual performance for stiffness modulation. To our knowledge, this work is among the first efforts in haptic AR for systematic augmentation of real object attributes with virtual forces, and it serves as an initial building block toward a general haptic AR system. Finally, several research issues identified during the feasibility study are introduced, with the aim of eliciting more research interest in this exciting yet unexplored area.
A Functional Approach to Volunteerism: Do Volunteer Motives Predict Task Preference?

A central premise of the functional approach is that the same behavior may serve different functions for different individuals. More recently, this approach has been used to understand the motives behind volunteering. The purpose of this study was to investigate whether certain volunteer tasks (e.g., reading to the blind, entering data) differentially satisfy certain motives (e.g., expression of values, career building) and whether individuals prefer tasks with benefits aligned with their own preferred volunteer motives. Results suggested that people idiosyncratically differentiate tasks based on the motives they satisfy. Furthermore, when given a choice, individuals prefer tasks with benefits that match their personally relevant motives. Practical implications for volunteer organizations are discussed.
Two Views of Emotional Perception: Some Empirical Suggestions

One stream in contemporary philosophical and psychological study of the emotions argues that they are perceptual capacities (e.g., Prinz 2004). 2 For instance, Jesse Prinz has recently defended the view that emotions are perceptions of bodily changes and, via these, of “core relational themes” (2004, 224–25). Core relational themes are, roughly, relations an individual has to his/her environment that pertain to that individual’s welfare (2004, 15–16). The present project is to compare and contrast two possible models of emotional perception. The central difference between these models is the notion of modularity that they use, and the corresponding overall view of the nature of the mind. I will suggest some empirical tests that might adjudicate between these different kinds of emotional modularity, and hence between these two models of emotional perception. I will conclude with some remarks about the extent of the relevance of this issue. So, suppose that emotions are perceptual capacities. How would one go about conceiving of and studying such capacities? A natural way to proceed is to use other perceptual capacities as a model: identify important characteristics of uncontroversial perceptual capacities, then see whether emotions have identical or similar features. This is
The Impact of Price Caps and Spending Cuts on U.S. Postsecondary Attainment

Increasing the postsecondary attainment rate of college-age youth is an important economic priority in the U.S. and in other developed countries. Yet little is known about whether different forms of public subsidy can increase degree completion. In this paper, we compare the impact of the marginal taxpayer dollar on postsecondary attainment when it is spent on lowering tuition prices versus increasing the quality of the college experience. We do so by estimating the causal impact of changes in tuition and spending on enrollment and degree completion in U.S. public postsecondary institutions between 1990 and 2013. We estimate these impacts using a newly assembled data set of legislative tuition caps and freezes, combined with variation in exposure to state budget shocks that is driven by differences in historical reliance on state appropriations. We find large impacts of spending on enrollment and degree completion. In contrast, we find no impact of price changes. Our estimates suggest that spending increases are more effective per-dollar than price cuts as a means of increasing postsecondary attainment.
The Empirical Correlates of Action and Structure: The Transition from School to Work

The paper attempts to link theoretical ideas concerning the relation of agency and structure with empirical research on the transition from school to work. In particular, some of the propositions of structuration theory are assessed in terms of their applicability to empirical research which investigates the impact of individual and structural variables on movement into the labour market, and the way the variables combine to determine entry into labour market segments. The data suggests that structural and individual factors are influential at all levels of the occupational hierarchy, but that the strength of influence varies at different points in the hierarchy. This supports the axiom of structuration theory which asserts that structure and activity are deeply implicated in each other in the process of social reproduction. However, the data further suggests the `duality of structure' principle has to be considerably modified in order to apprehend phenomena such as labour market processes. In this respect we believe that structure and action variables have to be viewed as loci of powers rooted in partly independent ontological domains but which interpenetrate each other in specific empirical areas at particular points in time and space.
Publication outcome of abstracts submitted to the American Academy of Ophthalmology meeting*

Objective Abstracts submitted to meetings are subject to less rigorous peer review than full-text manuscripts. This study aimed to explore the publication outcome of abstracts presented at the American Academy of Ophthalmology (AAO) annual meeting. Methods Abstracts presented at the 2008 AAO meeting were analyzed. Each presented abstract was sought via PubMed to identify if it had been published as a full-text manuscript. The publication outcome, journal impact factor (IF), and time to publication were recorded. Results A total of 690 abstracts were reviewed, of which 39.1% were subsequently published. They were published in journals with a median IF of 2.9 (range 0–7.2) and a median publication time of 426 days (range 0–2,133 days). A quarter were published in the journal Ophthalmology, with a shorter time to publication (median 282 vs. 534 days, p=0.003). Oral presentations were more likely to be published than poster presentations (57.8% vs. 35.9%, p<0.001) and in journals with higher IFs (3.2 vs. 2.8, p=0.02). Abstracts describing rare diseases had higher publication rates (49.4% vs. 38.0%, p=0.04) and were published in higher IF journals (3.7 vs. 2.9, p=0.03), within a shorter period of time (358 vs. 428 days, p=0.03). In multivariate analysis, affiliation with an institute located in the United States (p=0.002), abstracts describing rare diseases (p=0.03), and funded studies (p=0.03) were associated with publication in higher IF journals. Conclusions Almost 40% of abstracts were published. Factors that correlated with publication in journals with higher IF were a focus on rare diseases, affiliation with a US institute, and funding.
Multiplexing VBR video and training sequences on wireless fading channels

A time slotted multiple access scheme that shares bandwidth between source and training signals is proposed for the transmission of variable bit rate (VBR) video signals over non-ideal channels. The error performance is examined using finite state Markov chains that model both the VBR source traffic and the time variation of fading channels. The characteristic time-scale of the fade duration, the step-size parameter of the LMS equalizer training algorithm, and the number of training sequences allocated per time slot jointly influence the error performance. The consideration of the physical layer characteristics in the design of higher layer protocols enhances the performance of conventional application layer based preventive and reactive error control schemes. Simulation results for fast and slow fading channels show that the proposed channel access scheme can lead to an order of magnitude decrease in the bit error ratio if the combination of training overhead and step-size parameter are chosen judiciously with respect to the fading time-scale. In addition, the multiplexing efficiency of VBR encoded video is shown to be useful for limiting the channel access delays when training overhead is increased.
Cell-to-Cell Contact Results in a Selective Translocation of Maternal Human Immunodeficiency Virus Type 1 Quasispecies across a Trophoblastic Barrier by both Transcytosis and Infection

ABSTRACT Mother-to-child transmission can occur in utero, mainly intrapartum and postpartum in case of breastfeeding. In utero transmission is highly restricted and results in selection of viral variant from the mother to the child. We have developed an in vitro system that mimics the interaction between viruses, infected cells present in maternal blood, and the trophoblast, the first barrier protecting the fetus. Trophoblastic BeWo cells were grown as a tight polarized monolayer in a two-chamber system. Cell-free virions applied to the apical pole neither crossed the barrier nor productively infected BeWo cells. In contrast, apical contact with human immunodeficiency virus (HIV)-infected peripheral blood mononuclear cells (PBMCs) resulted in transcytosis of infectious virus across the trophoblastic monolayer and in productive infection correlating with the fusion of HIV-infected PBMCs with trophoblasts. We showed that viral variants are selected during these two steps and that in one case of in utero transmission, the predominant maternal viral variant characterized after transcytosis was phylogenetically indistinguishable from the predominant child's virus. Hence, the first steps of transmission of HIV-1 in utero appear to involve the interaction between HIV type 1-infected cells and the trophoblastic layer, resulting in the passage of infectious HIV by transcytosis and by fusion/infection, both leading to a selection of virus quasispecies.
Children's Concepts of Fair Sharing

Abstract This report of children's concepts of fairness takes as its rationale that the tentativeness of contemporary moral education reflects a lack of precise developmental schedules, and that there is a need for research to examine recent outlines of growth before widespread adoption of them by teachers. The Damon hierarchy of development of children's sense of positive justice is examined for its usefulness in predicting fairness in behaviour, and reliability in age patterning of its stated levels of reasoning. In general, it is the attributes of the various situations in which distribution is carried out, rather than conceptual growth, that seems to determine behaviour. The changes occurring with age are more quantitative than qualitative, and do not accord with expectations based on the Damon analysis. The hierarchy's value as a developmental schedule for teacher guidance may be questionable.
The effect of long term under- and over-feeding of sheep on milk and plasma fatty acid profiles and on insulin and leptin concentrations

Since sheep's milk is mainly used for cheese making and milk chemical composition and fatty acids (FA) profile affect cheese yield and quality, the objective of this study was to determine the effects of different feeding levels on milk chemical composition and FA profile, as well as on plasma FA profile, and on insulin and leptin concentrations. Twenty-four sheep were assigned to three homogeneous sub-groups. Throughout the experimental period each group was fed the same diet but in quantities which met 70% (under-feeding), 100% (control) and 130% (over-feeding) of their respective energy and crude protein requirements. The results showed that the underfed sheep had higher milk fat content compared with overfed. In blood plasma the concentrations of C18:0 and C18:1 in the underfed sheep were significantly higher compared with control and overfed sheep. The concentrations of leptin and insulin were significantly higher in overfed compared with underfed sheep. Underfeeding reduced the concentrations of short chain FA (SCFA) and medium chain FA (MCFA) and increased that of C18:0 and mono unsaturated FA (MUFA) in sheep milk fat compared with controls and overfed. The concentrations of C18:0, long chain FA (LCFA) and monounsaturated FA (MUFA) in milk were significantly higher and those of SCFA, MCFA and saturated FA (SFA) significantly lower in the underfed compared with the overfed sheep. In conclusion, long term under- and over-feeding affected the sheep milk chemical composition and FA profile which consequently has an impact on milk products yield (cheese and yogurt) and quality (human health).