The Body-Machine Interface: A New Perspective on an Old Theme

ABSTRACT

Body-machine interfaces establish a way to interact with a variety of devices, allowing their users to extend the limits of their performance. Recent advances in this field, ranging from computer interfaces to bionic limbs, have had important consequences for people with movement disorders. The authors provide an overview of the basic concepts underlying the body-machine interface with special emphasis on their use for rehabilitation and for operating assistive devices. They outline the steps involved in building such an interface and highlight the critical role of body-machine interfaces in addressing theoretical issues in motor control as well as their utility in movement rehabilitation.     

How do scientists select articles in the PubMed database? An empirical study of criteria and strategies

IntroductionThe present study investigated the strategies used by experienced researchers to find articles in an online bibliographic database.ObjectiveThe goal was to shed light on researchers’ actual search behaviour by empirically observing users during the search process.MethodWe asked 16 neuroscience researchers and 16 researchers in other disciplines of life sciences to perform five search tasks on neuroscience topics using the PubMed database. Think-aloud protocols were recorded while the participants performed the search tasks.ResultsAll researchers managed to find adequate references for the tasks in the limited amount of time allocated. Most participants used similar, very basic moves and tactics to perform the tasks. However, they behaved in many different ways when they had to decide whether to read the retrieved results or to modify their query (according to the number of references they obtained), or when selecting the one or two references they finally gave as answers among all possible answers.DiscussionVariability in participants’ behaviour may result from inter-individual differences in either the participants’ mental models of PubMed or cognitive abilities and styles, but the question requires further investigation. The data further suggest that developers of online search engines and databases should concentrate their efforts on improving simple-search interfaces and helping users to correct search errors in real time.     

Misfit disclinations and dislocations at crystal-glass interfaces

A theoretical model is suggested which describes misfit defect structures at crystal-glass interfaces. In the framework of the model the two basic types of misfit defect are distinguished: misfit disclinations (generated as extensions of parent disclinations present in the adjacent glassy phase) and 'dilatation' misfit dislocations (contributing to accommodation of the dilatation misfit associated with difference between the characteristic interatomic distances in the adjacent crystalline and glassy phases). The elastic energy density of crystal-glass interfaces is estimated.     

The effects of scenario-based risk information on perceptions of susceptibility to Chlamydia and HIV

Abstract

Objectives: The Self-Report Habit Index (SRHI) was originally reported as one-dimensional; however, habit has been described as characterised by several features. Moreover, one-dimensional models for the SRHI have demonstrated poor fit. Therefore, we aimed to compare multidimensional models with a one-dimensional model in both snacking and physical activity habits, besides examining further instrument characteristics.

Design: A cross-sectional study was conducted with high school and university students (n?=?555).

Main outcome measure: The SRHI adapted for physical activity and for snaking habits was applied at one time point.

Results: Nested models with one factor, two factors and three factors were compared. Next, a hierarchical second-order model was tested, and further validity issues, as well as invariance between habits, were examined. Three-dimensional models represented a better fit for both habits. However, fit was still inadequate in the snacking version. In addition, discriminant validity concerns emerged for the physical activity SRHI. Moreover, invariance between the snacking and the physical activity versions was not confirmed.

Conclusions: Considering the SRHI as composed by the dimensions of ‘lack of awareness’, ‘lack of control’ and ‘history of behavioural repetition’ seems to be more accurate. Nevertheless, our findings suggest that further research is needed.     

Energetics and kinetics of surfaces and interfaces in the Fe-Pb system

The energy and the diffusivity of interfaces in the solid Fe-liquid Pb system have been investigated in the temperature range 650-900°C. Grain-boundary grooves are formed at the solid Fe-liquid Pb interface and these have been studied by atomic force microscopy. From the topography of the grooves the relative interfacial energies and interfacial diffusivities are obtained. It is found that liquid Pb does not wet the grain boundaries in Fe. Possible mechanisms for the growth of the grain-boundary grooves are discussed.     

Algebraic logic for classical conjunction and disjunction

In this paper we study the relations between the fragment L of classical logic having just conjunction and disjunction and the variety D of distributive lattices, within the context of Algebraic Logic. We prove that these relations cannot be fully expressed either with the tools of Blok and Pigozzi's theory of algebraizable logics or with the use of reduced matrices for L. However, these relations can be naturally formulated when we introduce a new notion of model of a sequent calculus. When applied to a certain natural calculus for L, the resulting models are equivalent to a class of abstract logics (in the sense of Brown and Suszko) which we call distributive. Among other results, we prove that D is exactly the class of the algebraic reducts of the reduced models of L, that there is an embedding of the theories of L into the theories of the equational consequence (in the sense of Blok and Pigozzi) relative to D, and that for any algebra A of type (2,2) there is an isomorphism between the D-congruences of A and the models of L over A. In the second part of this paper (which will be published separately) we will also apply some results to give proofs with a logical flavour for several new or well-known lattice-theoretical properties.Dedicated to our master, Francesc d'A. Sales, on his 75th birthday     

Estimating Complex Measurement and Growth Models Using the R Package PLmixed

Measurement models, such as factor analysis and item response theory models, are commonly implemented within educational, psychological, and behavioral science research to mitigate the negative effects of measurement error. These models can be formulated as an extension of generalized linear mixed models within a unifying framework that encompasses various kinds of multilevel models and longitudinal models, such as partially nonlinear latent growth models. We introduce the R package PLmixed, which implements profile maximum likelihood estimation to estimate complex measurement and growth models that can be formulated within the general modeling framework using the existing R package lme4 and function optim. We demonstrate the use of PLmixed through two examples before concluding with a brief overview of other possible models.     

Wholistic Theology as a Conceptual Foundation for Services for the Oldest Old

SUMMARY

Social service agencies are focusing more and more on the “old-old.” Some organizations have secular missions that address multiple domains (i.e., physiological, economic, social, etc.). Other agencies, developed by the religious community, designate spirituality as a domain to be addressed in serving the “old-old.” This paper examines interfaces between secular social service organizations and those persons (whether staff, board or religious leaders) who attempt to provide a wholistic perspective for service provision to the “old-old.”     

Information search activity: An overview

IntroductionThis article exposes a brief history of information search models, from general and behavioural models to cognitive ones and presents recent theoretical advances in this research field.Literature findingsSince the beginning of 1990s, many theoretical models have tried to describe and predict the human behaviours involved in the information search tasks, and specifically when this activity is performed in computer systems. Some of these models elaborated by psychologists have attempted to infer the cognitive processes involved.DiscussionInformation search can be considered as a complex cognitive activity that involves various individual (cognitive, affective), contextual and social factors.ConclusionWe also suggest research issues to be developed in order to increase our knowledge in this area and we plead for further research on specific concepts depending on future and/or recent areas of interest.     

Latent structure and measurement invariance of the Hospital Anxiety and Depression Scale in cancer outpatients

Background/ObjectiveThe aim of the present study was to compare competing psychometric models and analyze measurement invariance of the Hospital Anxiety and Depression Scale (HADS) in cancer outpatients.MethodThe sample included 3,260 cancer outpatients. Latent structure of the HADS was analyzed using confirmatory factor analysis (CFA) with robust maximum likelihood estimation (MLR). Measurement invariance was tested for age, time of response, gender, and cancer type by comparing nested multigroup CFA models with parameter restrictions.ResultsExcept for the one-factor solutions, all models showed acceptable model fit and measurement invariance. The model with the best fit was the originally proposed two-factor model with exclusion of two items. The one-factor solutions showed inacceptable model fit and were not invariant for age and gender.ConclusionsThe HADS has a robust two-factor structure in cancer outpatients. We recommend excluding item 7 and 10 when screening for anxiety and depression.     

Social anxiety and interpersonal stress generation: the moderating role of interpersonal distress

Background and Objectives: Existing models of social anxiety scarcely account for interpersonal stress generation. These models also seldom include interpersonal factors that compound the effects of social anxiety. Given recent findings that two forms of interpersonal distress, perceived burdensomeness and thwarted belongingness, intensify social anxiety and cause interpersonal stress generation, these two constructs may be especially relevant to examining social anxiety and interpersonal stress generation together.

Design: The current study extended prior research by examining the role of social anxiety in the occurrence of negative and positive interpersonal events and evaluated whether interpersonal distress moderated these associations.

Methods: Undergraduate students (N?=?243; M?=?20.46 years; 83% female) completed self-report measures of social anxiety, perceived burdensomeness, and thwarted belongingness, as well as a self-report measure and clinician-rated interview assessing negative and positive interpersonal events that occurred over the past six weeks.

Results: Higher levels of social anxiety were associated only with a higher occurrence of negative interpersonal dependent events, after controlling for depressive symptoms. This relationship was stronger among individuals who also reported higher levels of perceived burdensomeness, but not thwarted belongingness.

Conclusions: It may be important to more strongly consider interpersonal stress generation in models of social anxiety.     

Mediation analysis of decisional balance,sun avoidance and sunscreen use in the precontemplation and preparation stages for sun protection

Objective: Mediation analyses of sun protection were conducted testing structural equation models using longitudinal data with three waves. An effect was said to be mediated if the standardised path between processes of change, decisional balance and sun protection outcomes was significant.

Design: Longitudinal models of sun protection using data from individuals in the precontemplation (N = 964) and preparation (N = 463) stages who participated of an expert system intervention.

Main outcome measures: Nine processes of change for sun protection, decisional balance constructs of sun protection (pros and cons), sun avoidance behaviour and sunscreen use.

Results: With the exception of two processes in the preparation stage, processes of change predicted the pros (r = .126–.614), and the pros predicted the outcomes (r = .181–.272). Three models with the cons as mediator in the preparation stage, and none in the precontemplation stage, showed a mediated relationship between processes and outcomes.

Conclusion: In general, mediation analyses found both the process of change-to-pros and pros-to-behaviour paths significant for both precontemplation and preparation stages, and for both sun avoidance and sunscreen use outcomes. Findings provide support for the importance of assessing the role of underlying risk cognitions in improving sun protection adherence.     

General canonical models for graded normal logics (graded modalities IV)

We prove the canonical models introduced in [D] do not exist for some graded normal logics with symmetric models, namelyKB°, KBD°, KBT°, so that we define a new kind of canonical models, the general ones, and show they exist and work well in every case.     

Self-focused attention and safety behaviors across group therapies for social anxiety disorder

Background: Self-focused attention (SFA) and safety behaviors are two variables implicated in the maintenance of social anxiety disorder (SAD).

Design: The present study examined SFA and safety behaviors across two therapies for SAD, cognitive behavioral group therapy (CBGT) and mindfulness and acceptance-based group therapy (MAGT).

Method: Participants with symptoms meeting criteria for SAD (N?=?137) were randomly assigned to the 12-week-treatment groups (n?=?53 for each condition) or a waitlist control (n?=?31). Variables were assessed at baseline, midtreatment, posttreatment, and a 3-month follow-up.

Results: Both treatment conditions reported significantly lower SFA and safety behaviors compared to control, but did not differ from one another at posttreatment. Mediation analyses supported the following models: (1) safety behaviors mediating the relationship between SFA and social anxiety, and (2) SFA mediating the relationship between safety behaviors and social anxiety. These models were supported for both treatment groups.

Conclusions: Both treatments may have the potential to reduce the SFA and safety behaviors that serve to maintain SAD.     

Multilayered phase formation after high-fluence implantation of nickel into aluminium

The formation of crystalline and amorphous layers has been observed in Al crystals after 5MeV Ni implantation up to a fluence of 7.6 10 17 Ni atomscm -2 . The layers are structured into sublayers perpendicular to the implantation direction with sharp interfaces between the phases and almost symmetrically arranged to both sides of the maximum of the implantation profile. The sublayers of thickness of the order of 100nm were analysed by transmission electron microscopy. They consist of polycrystalline Al 3 Ni, crystalline Al 3 Ni precipitates and small amorphous zones, depending on the local Ni implantation concentration.     

The impact of auditory continual feedback on take-overs in Level 3 automated vehicles

ObjectiveTo implement auditory continual feedback into the interface design of a Level 3 automated vehicle and to test whether gaze behavior and reaction times of drivers improved in take-over situations.BackgroundWhen required to assume manual control in take-over situations, drivers of Level 3 automated vehicles are less likely than conventional drivers to spot potential hazards, and their reaction time is longer. Therefore, it is crucial that the interface of Level 3 automated vehicles will be designed to improve drivers’ performance in take-over situations.MethodIn two experiments, participants drove a simulated route in a Level 3 automated vehicle for 35 min with one imminent take-over event. Participants’ gaze behavior and performance in an imminent take-over event were monitored under one of three auditory interface designs: (1) Continual feedback. A system that provides verbal driving-related feedback; (2) Persistent feedback. A system that provides verbal driving-related feedback and a persistent beep; and (3) Chatter feedback. A system that provides verbal non-driving-related feedback. Also, there was a control group without feedback.ResultsUnder all three auditory feedback designs, the number of drivers' on-road glances increased compared to no feedback, but none of the designs shortened reaction time to the imminent event.ConclusionIncreasing the number of on-road glances during automated driving does not necessarily improve drivers’ attention to the road and their reaction times during take-overs.ApplicationPossible implications for the effectiveness of auditory continual feedback should be considered when designing interfaces for Level 3 automated vehicles.     

On an Intuitionistic Modal Logic

In this paper we consider an intuitionistic variant of the modal logic S4 (which we call IS4). The novelty of this paper is that we place particular importance on the natural deduction formulation of IS4— our formulation has several important metatheoretic properties. In addition, we study models of IS4— not in the framework of Kirpke semantics, but in the more general framework of category theory. This allows not only a more abstract definition of a whole class of models but also a means of modelling proofs as well as provability.     

HREM study of the chemical nature of twin planes in CuAlO2

Abstract

High-resolution electron microscopy has been used to study the atomic structure of twins in the binary oxide CuAlO₂. This compound is an occasional product of the bonding between pre-oxidized copper and alumina; its peculiarity is to exhibit a twinned microstructure, owing to the occurrence of two enantiomorphic right- and left-handed configurations. The microstructural examination at high resolution reveals that twin planes are located on copper basal planes rather than aluminium planes; this result is discussed on the basis of an analysis of the various possible stacking sequences which can reasonably be considered to occur at the twin interfaces.     

Investigating the Performance of Alternate Regression Weights by Studying All Possible Criteria in Regression Models with a Fixed Set of Predictors

We describe methods for assessing all possible criteria (i.e., dependent variables) and subsets of criteria for regression models with a fixed set of predictors, x (where x is an n×1 vector of independent variables). Our methods build upon the geometry of regression coefficients (hereafter called regression weights) in n-dimensional space. For a full-rank predictor correlation matrix, R _xx, of order n, and for regression models with constant R ² (coefficient of determination), the OLS weight vectors for all possible criteria terminate on the surface of an n-dimensional ellipsoid. The population performance of alternate regression weights—such as equal weights, correlation weights, or rounded weights—can be modeled as a function of the Cartesian coordinates of the ellipsoid. These geometrical notions can be easily extended to assess the sampling performance of alternate regression weights in models with either fixed or random predictors and for models with any value of R ². To illustrate these ideas, we describe algorithms and R (R Development Core Team, 2009) code for: (1) generating points that are uniformly distributed on the surface of an n-dimensional ellipsoid, (2) populating the set of regression (weight) vectors that define an elliptical arc in ℝ ⁿ , and (3) populating the set of regression vectors that have constant cosine with a target vector in ℝ ⁿ . Each algorithm is illustrated with real data. The examples demonstrate the usefulness of studying all possible criteria when evaluating alternate regression weights in regression models with a fixed set of predictors.