Making the case for objective performance metrics in newborn screening by tandem mass spectrometry

The expansion of newborn screening programs to include multiplex testing by tandem mass spectrometry requires understanding and close monitoring of performance metrics. This is not done consistently because of lack of defined targets, and interlaboratory comparison is almost nonexistent. Between July 2004 and April 2006 (N=176,185 cases), the overall performance metrics of the Minnesota program, limited to MS/MS testing, were as follows: detection rate 1:1,816, positive predictive value 37% (54% in 2006 till date), and false positive rate 0.09%. The repeat rate and the proportion of cases with abnormal findings actually been reported are new metrics proposed here as an objective mean to express the overall noise in a program, where noise is defined as the total number of abnormal results obtained using a given set of cut-off values. On the basis of our experience, we propose the following targets as evidence of adequate analytical and postanalytical performance: detection rate 1:3,000 or higher, positive predictive value>20%, and false positive rate<0.3%.     

Humean dispositionalism

Humean metaphysics is characterized by a rejection of necessary connections between distinct existences. Dispositionalists claim that there are basic causal powers. The existence of such properties is widely held to be incompatible with the Humean rejection of necessary connections. In this paper I present a novel theory of causal powers that vindicates the dispositionalist claim that causal powers are basic, without embracing brute necessary connections. The key assumptions of the theory are that there are natural types of causal processes, and that manifestations of powers are identified with certain kinds of causal processes. From these assumptions, the modal features of powers are explained in terms of internal relations between powers themselves and the process-types in which powers are manifested.     

Structural Equation Modeling of Spatial Presence: The Influence of Cognitive Processes and Traits

This article examines the formation process of spatial presence, which is conceived as a two-step process involving the construction of a mental model of the mediated environment, followed by the emergence of spatial presence. During both stages, cognitive processes and user traits are in effect. We present data derived from a pooled set of data of three studies using the same virtual environment. Structural equation modeling is used to confirm the proposed theoretical model. The results show that attention and the trait of visual spatial imagery are positive predictors of the mental model of the mediated environment. In the second step, the formation of spatial presence is governed by involvement, the suspension of disbelief, and the domain-specific interest, together with the mental model.     

Defining the vital condition for organ donation

The issue of organ donation and of how the donor pool can or should be increased is one with significant practical, ethical and logistic implications. Here we comment on an article advocating a paradigm change in the so-called "dead donor rule". Such change would involve the societal and legal abandonment of the above rule and the introduction of mandated choice. In this commentary, we review some of the problems associated with the proposed changes as well as the problems associated with the current model. We emphasize the continuing problems with the definition of death and the physiological process of dying; we discuss the difficulties associated with a dichotomous view of death; we review the difficulties with non-beating heart donation and emphasize the current limitations of society's understanding of these complex issues. We conclude that public education remains the best approach and that such education should not be merely promotion of a particular ideology but honest debate of what is socially and morally acceptable and appropriate given the changes in vital organ support technology and the need to respect patient autonomy.     

A comparison of dyadic interactions and coping with still‐face in healthy pre‐term and full‐term infants

Pre‐term birth has a significant impact on infants' social and emotional competence, however, little is known about regulatory processes in pre‐term mother‐infant dyads during normal or stressful interactions. The primary goals of this study were to investigate the differences in infant and caregiver interactive behaviour and dyadic coordination of clinically healthy pre‐term compared to full‐term infant‐mother dyads and to examine pre‐term infants' capacity for coping with stress using the face‐to‐face still‐face paradigm (FFSF). Fifty mother‐infant dyads, including 25 pre‐term infants and 25 full‐term infants were videotaped during the FFSF. All infants were 6–9 months of age (corrected for gestational age in the pre‐term group). Infant and maternal socio‐emotional expressivity and self‐regulatory behaviours were coded and measures of dyadic coordination (Matching, Reparation Rate, and Synchrony) were calculated. There were no significant differences in infant and caregiver socio‐emotional behaviours between the two groups and both groups demonstrated the still‐face (SF) effect and the reunion effect. There was a difference in self‐regulatory behaviour. Pre‐term infants were more likely than full‐term infants to use distancing (e.g., by turning away, twisting, or arching) from their mothers during the FFSF. Additionally, during the Reunion episode of the FFSF pre‐term infants showed more social monitoring compared to full‐term infants. Regardless of the birth status, the dyads showed less coordination and a slower rate of reparation during the Reunion episode than during the Play episode. The higher proportion of distancing in the pre‐term group and the increase in social monitoring suggest that even in normal interactions pre‐term infants may experience a higher level of stress and have less capacity for self‐regulation compared to the full‐terms and that pre‐term infants appear to use a compensatory strategy of increased social monitoring to cope with the stress of renegotiating the interaction during Reunion. The findings suggest that pre‐term infants have different regulatory and interactive capacities than full‐term infants.     

How Emotional Media Reports Influence Attitude Formation and Change: The Interplay of Attitude Base,Attitude Certainty,and Persuasion

This study examined the influence of an emotionally arousing writing style on attitude formation and change. It has been proposed that different writing styles induce attitudes based on either affect or cognition and with either high or low certainty. Previous work indicates that the interplay of these attitude characteristics determines the persuasiveness of emotional and rational media appeals. To test the hypotheses, participants in an experimental study read articles from a magazine about a fictitious attitude object. In the first step, 4 different types of attitudes varying in base and level of certainty were induced through a respectively manipulated article. In the second step, these attitudes were challenged by an additional article, which presented either an emotional or rational persuasive appeal. The results supported hypotheses on attitude induction through media stimuli and 3 of 4 hypotheses regarding the persuasiveness of emotionally and rationally written articles.