Automatic covariate selection in logistic models for chest pain diagnosis: A new approach

A newly established method for optimizing logistic models via a minorization-majorization procedure is applied to the problem of diagnosing acute coronary syndromes (ACS). The method provides a principled approach to the selection of covariates which would otherwise require the use of a suboptimal method owing to the size of the covariate set. A strategy for building models is proposed and two models optimized for performance and for simplicity are derived via ten-fold cross-validation. These models confirm that a relatively small set of covariates including clinical and electrocardiographic features can be used successfully in this task. The performance of the models is comparable with previously published models using less principled selection methods. The models prove to be portable when tested on data gathered from three other sites. Whilst diagnostic accuracy and calibration diminishes slightly for these new settings, it remains satisfactory overall. The prospect of building predictive models that are as simple as possible for a required level of performance is valuable if data-driven decision aids are to gain wide acceptance in the clinical situation owing to the need to minimize the time taken to gather and enter data at the bedside

How can the blow of math difficulty on elementary school children’s motivational, cognitive, and affective experiences be dampened? : The critical role of autonomy-supportive instructions

Although teachers are recommended to create a stimulating learning environment in which children can use, perfect, and extend their skills, this is far from easy. In many cases, identifying the optimal difficulty level of learning tasks involves a trial-and-error process during which teachers offer children too difficult tasks, with negative outcomes as a result. This experimental study investigated if autonomy-supportive instructions could dampen or even cancel out these presumed negative outcomes associated with math difficulty in elementary schoolchildren (N = 479; M-age = 9.41). After varying an autonomy-supportive versus a controlling instructional style through a comic book, children solved a series of either easy-medium or difficult math exercises, followed by the completion of questionnaires and the opportunity to choose the difficulty level of a final set of exercises to work on independently. Children who solved difficult, relative to easier, exercises reported less interest, more irritation, and more cognitive disengagement, while also seeking less challenge when asked to work independently. Need-based experiences of competence and autonomy accounted for these effects. Yet, the impairing impact of task difficulty could, at least partially, be dampened through the use of an autonomy-supportive relative to a controlling instructional style, which led to enhanced autonomy satisfaction. These findings largely occurred independent of children's motives for mathematics. The results have high practical value, especially for poor performers and children with mathematical learning disabilities, who find math to be harder overall. Limitations and implications for practice are discussed. Educational Impact and Implications Statement : Autonomy-supportive instructions (e.g., inviting language, meaningful rationale) were found to dampen the impairing effects of too difficult math tasks on children's motivational, cognitive, and affective experiences. This is especially important for poor performers and children with mathematical learning disabilities, who find math to be harder overall. An autonomy-supportive environment and avoiding too hard learning material may stimulate children to accept new challenges, thereby possibly improving chances for later academic/job success

Seeking Self-Certainty in an Uncertain Time: Attachment Style and Self-Esteem in Emerging Adulthood

Emerging adulthood is a defining period for individuals aged 18-29, marked by unpredictability and excitement as individuals figure out the paths their lives will take with regard to work, relationships, and other domains (Arnett, 2004). The present study investigated associations between attachment style and level of self-esteem for emerging adults, and also attempted to understand the bi-directional influence of developmental stages on attachment style and self-esteem. In addition, the study explored if and how one’s presence in a romantic partnership, whether that partnership be stable or unstable, mediated these relationships. 199 emerging adults completed Levine and Heller’s attachment questionnaire which originated from the Experience in Close Relationships questionnaire (ECR), the Rosenberg self-esteem scale, and the Inventory of the Dimensions of Emerging Adulthood. Findings uphold that secure attachment may help to incline individuals towards positive, or healthy self-esteem during emerging adulthood, and anxious attachment may incline individuals to negative or low self-esteem. Avoidant attachment was not linked to self-esteem. Secure attachment was found to be linked to the “self-focused” phase, in addition to the “in-between stage;” self-focusedness was also negatively linked to securely attached individual’s self-esteem. Being in a stable romantic relationship in emerging adulthood was found to have a statistically significant positive impact on the self-esteem of secures. Finally, being “other-focused” and an “experimenter” was found to be linked to one’s presence in a stable romantic relationship, and being self-focused was linked to one’s presence in a more unstable relationship

Existence of optimal ultrafilters and the fundamental complexity of simple theories

In the first edition of Classification Theory, the second author characterized the stable theories in terms of saturation of ultrapowers. Prior to this theorem, stability had already been defined in terms of counting types, and the unstable formula theorem was known. A contribution of the ultrapower characterization was that it involved sorting out the global theory, and introducing nonforking, seminal for the development of stability theory. Prior to the present paper, there had been no such characterization of an unstable class. In the present paper, we first establish the existence of so-called optimal ultrafilters on Boolean algebras, which are to simple theories as Keisler's good ultrafilters are to all theories. Then, assuming a supercompact cardinal, we characterize the simple theories in terms of saturation of ultrapowers. To do so, we lay the groundwork for analyzing the global structure of simple theories, in ZFC, via complexity of certain amalgamation patterns. This brings into focus a fundamental complexity in simple unstable theories having no real analogue in stability.Comment: The revisions aim to separate the set theoretic and model theoretic aspects of the paper to make it accessible to readers interested primarily in one side. We thank the anonymous referee for many thoughtful comment

Morphological transparency and markedness matter in heritage speaker gender processing: an EEG study

The present study investigated the qualitative nature of grammatical gender knowledge and processing in heritage speakers (HSs) of Spanish living in the United States. Forty-four adult Spanish HS bilinguals participated, completing a behavioral grammatical gender assignment task and a grammaticality judgment task (GJT) while their brain activity was recorded using electroencephalography (EEG). The EEG GJT task included grammatical and ungrammatical sentences with grammatical gender violations on inanimate nouns, where transparency of the morpho(phono)logical cue and markedness were manipulated. The results of this study revealed that grammatical gender violations elicited the typical P600 effect across all relevant conditions, indicating that the grammatical representations and processing of grammatical gender in HSs are qualitatively similar to those in Spanish-dominant native speakers. Given the experimental manipulation in this study, these findings also suggest that both morphological transparency and markedness play significant roles in how grammatical gender is processed. However, the results of this study differ from those reported in previous studies with Spanish-dominant native speakers, as the P600 effect found was accompanied by a biphasic N400 effect. This pattern of results is interpreted as further evidence that the bilingual experience of HSs modulates certain aspects of morphosyntactic processing, particularly conferring a greater reliance on morphology. Additionally, the results of this study highlight the importance of incorporating neurolinguistic online processing methods to better understand what underlies HS bilingual competence and processing outcomes