1,763 research outputs found
Non-suicidal self-injury in adolescence: a longitudinal study of the relationship between NSSI, psychological distress and perceived parenting
Objective: The present study investigates whether either adolescents' psychological distress and/or perceived parenting predicted the occurrence of NSSI. Furthermore, the consequences of NSSI are examined in a three-wave longitudinal study. Design: The sample at time 1 (age 12) consisted of 1396 adolescent reports and 1438 parent reports. At time 2 (age 13), 827 adolescent reports and 936 parent reports were obtained. Time 3 (age 14) included 754 adolescent reports and 790 parent reports. Psychological distress of adolescents was measured using the Strengths and Difficulties Questionnaire. Perceived parenting behaviors were examined by the Parental Behavior Scale and the Psychological Control Scale. Results: A total of 10% of the adolescents engaged in NSSI at least once before age 15. Higher psychological distress of adolescents at time 1 was associated with the presence of NSSI at time 2 or 3. The association between psychological distress at time 1 and perception of decreased parental rule setting at time 3 was mediated by the presence of NSSI at time 2. Conclusions: The present study showed that psychological distress at age 12 predicts NSSI over time and that parental awareness of NSSI changes the perception of parenting behaviors. (C) 2014 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved
Exploring Planets with Directed Aerial Robot Explorers
Global Aerospace Corporation (GAC) is developing a revolutionary system architecture for exploration of planetary atmospheres and surfaces from atmospheric altitudes. The work is supported by the NASA Institute for Advanced Concepts (NIAC). The innovative system architecture relies upon the use of Directed Aerial Robot Explorers (DAREs), which essentially are long-duration-flight autonomous balloons with trajectory control capabilities that can deploy swarms of miniature probes over multiple target areas. Balloon guidance capabilities will offer unprecedented opportunities in high-resolution, targeted observations of both atmospheric and surface phenomena. Multifunctional microprobes will be deployed from the balloons once over the target areas, and perform a multitude of functions, such as atmospheric profiling or surface exploration, relaying data back to the balloons or an orbiter. This architecture will enable low-cost, low-energy, long-term global exploration of planetary atmospheres and surfaces. This paper focuses on a conceptual analysis of the DARE architecture capabilities and science applications for Venus, Titan and Jupiter. Preliminary simulations with simplified atmospheric models show that a relatively small trajectory control wing can enable global coverage of the atmospheres of Venus and Titan by a single balloon over a 100-day mission. This presents unique opportunities for global in situ sampling of the atmospheric composition and dynamics, atmospheric profiling over multiple sites with small dropsondes and targeted deployment of surface microprobes. At Jupiter, path guidance capabilities of the DARE platforms permits targeting localized regions of interest, such as "hot spots" or the Great Red Spot. A single DARE platform at Jupiter can sample major types of the atmospheric flows (zones and belts) over a 100-day mission. Observations by deployable probes would reveal if the differences exist in radiative, dynamic and compositional environments at these sites
Venus Interior Structure Mission (VISM): Establishing a Seismic Network on Venus
Magellan radar data show the surface of Venus to contain a wide range of geologic features (large volcanoes, extensive rift valleys, etc.). Although networks of interconnecting zones of deformation are identified, a system of spreading ridges and subduction zones like those that dominate the tectonic style of the Earth do not appear to be present. In addition, the absence of a mantle low-viscosity zone suggests a strong link between mantle dynamics and the surface. As a natural follow-on to the Magellan mission, establishing a network of seismometers on Venus will provide detailed quantitative information on the large scale interior structure of the planet. When analyzed in conjunction with image, gravity, and topography information, these data will aid in constraining mechanisms that drive surface deformation
Automatic learning of structural knowledge from geographic information for updating land cover mapas
Child Maltreatment, Non-Suicidal Self-Injury, and the Mediating Role of Self-Criticism
We examined the relation between child maltreatment and non-suicidal self-injury (NSSI). Participants were 86 adolescents who completed measures of child maltreatment, self-criticism, perceived criticism, depression, and NSSI. Analyses revealed significant, small-to-medium associations between specific forms of child maltreatment (physical neglect, emotional abuse, and sexual abuse) and the presence of a recent history of NSSI. Emotional and sexual abuse had the strongest relations with NSSI, and the data supported a theoretical model in which self-criticism mediates the relation between emotional abuse and engagement in NSSI. Specificity for the mediating role of self-criticism was demonstrated by ruling out alternative mediation models. Taken together, these results indicate that several different forms of childhood maltreatment are associated with NSSI and illuminate one mechanism through which maltreatment may be associated with NSSI. Future research is needed to test the temporal relation between maltreatment and NSSI and should aim to identify additional pathways to engagement in NSSI.Psycholog
Bregman Voronoi Diagrams: Properties, Algorithms and Applications
The Voronoi diagram of a finite set of objects is a fundamental geometric
structure that subdivides the embedding space into regions, each region
consisting of the points that are closer to a given object than to the others.
We may define many variants of Voronoi diagrams depending on the class of
objects, the distance functions and the embedding space. In this paper, we
investigate a framework for defining and building Voronoi diagrams for a broad
class of distance functions called Bregman divergences. Bregman divergences
include not only the traditional (squared) Euclidean distance but also various
divergence measures based on entropic functions. Accordingly, Bregman Voronoi
diagrams allow to define information-theoretic Voronoi diagrams in statistical
parametric spaces based on the relative entropy of distributions. We define
several types of Bregman diagrams, establish correspondences between those
diagrams (using the Legendre transformation), and show how to compute them
efficiently. We also introduce extensions of these diagrams, e.g. k-order and
k-bag Bregman Voronoi diagrams, and introduce Bregman triangulations of a set
of points and their connexion with Bregman Voronoi diagrams. We show that these
triangulations capture many of the properties of the celebrated Delaunay
triangulation. Finally, we give some applications of Bregman Voronoi diagrams
which are of interest in the context of computational geometry and machine
learning.Comment: Extend the proceedings abstract of SODA 2007 (46 pages, 15 figures
Droplet actuation induced by coalescence: experimental evidences and phenomenological modeling
This paper considers the interaction between two droplets placed on a
substrate in immediate vicinity. We show here that when the two droplets are of
different fluids and especially when one of the droplet is highly volatile, a
wealth of fascinating phenomena can be observed. In particular, the interaction
may result in the actuation of the droplet system, i.e. its displacement over a
finite length. In order to control this displacement, we consider droplets
confined on a hydrophilic stripe created by plasma-treating a PDMS substrate.
This controlled actuation opens up unexplored opportunities in the field of
microfluidics. In order to explain the observed actuation phenomenon, we
propose a simple phenomenological model based on Newton's second law and a
simple balance between the driving force arising from surface energy gradients
and the viscous resistive force. This simple model is able to reproduce
qualitatively and quantitatively the observed droplet dynamics
Creating a FACETS digital toolkit to promote quality of life of people with multiple sclerosis through Participatory Design
In this paper, we report on the first stages of creating a stand-alone digital toolkit focusing on the
homework elements of FACETS (Fatigue: Applying Cognitive behavioural and Energy effectiveness
Techniques to lifeStyle). FACETS is an evidence-based face-to-face fatigue management group
programme for people with multiple sclerosis. This paper details the participatory design process
from requirements elicitation to initial prototyping and how offline activities linked to each session
have been mapped in the digitised solution (mobile app)
Exploring strategies used following a group-based fatigue management programme for people with multiple sclerosis (FACETS) via the Fatigue Management Strategies Questionnaire (FMSQ)
Objectives: To explore cross-sectional patterns of use of fatigue management strategies in people with multiple sclerosis (MS) who had attended a groupbased fatigue management programme, Fatigue: Applying Cognitive behavioural and Energy effectiveness Techniques to lifeStyle ('FACETS'). In a multicentre randomised controlled trial (RCT) the FACETS programme was shown to reduce fatigue severity and improve self-efficacy and quality of life. Design: A questionnaire substudy within a RCT involving the self-completed Fatigue Management Strategies Questionnaire (FMSQ). The FMSQ includes: (1) closed questions about the use and helpfulness of fatigue management strategies taught in FACETS and (2) open items about changes to lifestyle, attitudes or expectations, barriers or difficulties encountered and helpful strategies not covered in FACETS. Participants: All had a clinical diagnosis of MS, significant fatigue, were ambulatory and had attended at least 4 of 6 scheduled FACETS sessions. Methods: Participants (n=72) were posted the FMSQ with a prepaid return envelope 4 months after the end of the FACETS programme. Results: 82% (59/72) of participants returned the FMSQ. The fatigue management strategies most frequently used since attending FACETS were prioritisation (80%), pacing (78%), saying no to others (78%), grading tasks (75%) and challenging unhelpful thoughts (71%). Adding in those participants who were already using the respective strategies prior to FACETS, the three most used strategies at 4 months were prioritisation (55/59), grading (54/59) and pacing (53/58). Free-text comments illustrated the complex interplay between attitudes/expectations, behaviours, emotions and the environment. Issues related to expectations featured strongly in participants' comments. Expectations (from self and others) were both facilitators and barriers to effective fatigue management. Conclusions: Individuals' comments highlighted the complex, multifaceted nature of fatigue management. Revising expectations and a greater acceptance of fatigue were important shifts following the programme. Findings support the relevance of a cognitive behavioural approach for fatigue management. Booster sessions might be a useful addition to the FACETS programme
Inducing Interpretable Voting Classifiers without Trading Accuracy for Simplicity: Theoretical Results, Approximation Algorithms
Recent advances in the study of voting classification algorithms have brought
empirical and theoretical results clearly showing the discrimination power of
ensemble classifiers. It has been previously argued that the search of this
classification power in the design of the algorithms has marginalized the need
to obtain interpretable classifiers. Therefore, the question of whether one
might have to dispense with interpretability in order to keep classification
strength is being raised in a growing number of machine learning or data mining
papers. The purpose of this paper is to study both theoretically and
empirically the problem. First, we provide numerous results giving insight into
the hardness of the simplicity-accuracy tradeoff for voting classifiers. Then
we provide an efficient "top-down and prune" induction heuristic, WIDC, mainly
derived from recent results on the weak learning and boosting frameworks. It is
to our knowledge the first attempt to build a voting classifier as a base
formula using the weak learning framework (the one which was previously highly
successful for decision tree induction), and not the strong learning framework
(as usual for such classifiers with boosting-like approaches). While it uses a
well-known induction scheme previously successful in other classes of concept
representations, thus making it easy to implement and compare, WIDC also relies
on recent or new results we give about particular cases of boosting known as
partition boosting and ranking loss boosting. Experimental results on
thirty-one domains, most of which readily available, tend to display the
ability of WIDC to produce small, accurate, and interpretable decision
committees
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