Observational Features of Black Holes

Recently considered a very attracting possibility to detect retro-MACHOs, i.e. retro-images of the Sun by a Schwarzschild black hole. In this paper we discuss glories (mirages) formed near rapidly rotating Kerr black hole horizons and propose a procedure to measure masses and rotation parameters analyzing these forms of mirages. In some sense that is a manifestation of gravitational lens effect in the strong gravitational field near black hole horizon and a generalization of the retro-gravitational lens phenomenon. We analyze the case of a Kerr black hole rotating at arbitrary speed for some selected positions of a distant observer with respect to the equatorial plane of a Kerr black hole. We discuss glories (mirages) formed near rapidly rotating Kerr black hole horizons and propose a procedure to measure masses and rotation parameters analyzing these forms of mirages. Some time ago suggested to search shadows at the Galactic Center. In this paper we present the boundaries for shadows calculated numerically. We also propose to use future radio interferometer RADIOASTRON facilities to measure shapes of mirages (glories) and to evaluate the black hole spin as a function of the position angle of a distant observer.Comment: Plenary talk presented at Workshop on High Energy Physics&Field Theory (Protvino, Russia, 2004

BabblePlay : An app for infants, controlled by infants, to improve early language outcomes

This project set out to develop an app for infants under one year of age that responds in real time to language-like infant utterances with attractive images on an iPad screen. Language-like vocalisations were defined as voiced utterances which were not high pitched squeals, nor shouts. The app, BabblePlay, was intended for use in psycholinguistic research to investigate the possible causal relationship between early canonical babble and early onset of word production. It is also designed for a clinical setting, (1) to illustrate the importance of feedback as a way to encourage infant vocalisations, and (2) to provide consonant production practice for infant populations that do not vocalise enough or who vocalise in an atypical way, specifically, autistic infants (once they have begun to produce consonants). This paper describes the development and testing of BabblePlay, which responds to an infant’s vocalisations with colourful moving shapes on the screen that are analogous to some features of the infant’s vocalization including loudness and duration. Validation testing showed high correlation between the app and two human judges in identifying vocalisations in 200 minutes of BabblePlay recordings, and a feasibility study conducted with 60 infants indicates that they can learn the contingency between their vocalisations and the appearance of shapes on the screen in one five minute BabblePlay session. BabblePlay meets the specification of being a simple and easy- to-use app. It has been shown to be a promising tool for research on infant language development that could lead to its use in home and professional environments to demonstrate the importance of immediate reward for vocal utterances to increase vocalisations in infants

‘Did I just do that?’ : Six-month-olds learn the contingency between their vocalisations and a visual reward in 5 minutes

It has been shown that infants can increase or modify a motorically available behaviour such as sucking, kicking, arm waving, etc., in response to a positive visual reinforcement (e.g., DeCasper & Fifer, 1980; Millar, 1990; Rochat & Striano, 1999; Rovee-Collier, 1997; Watson & Ramey, 1972). We tested infants to determine if they would also change their vocal behaviour in response to contingent feedback which lacks the social, emotional and auditory modelling typical of parent-child interaction. Here we show that in a single five-minute session infants increased the rate of their vocalisations in order to control the appearance of colourful shapes on an iPad screen. This is the first experimental study to demonstrate that infants can rapidly learn to increase their vocalisations when given positive reinforcement with no social element. This work sets the foundations for future studies into the causal relationship between the number of early vocalisations and the onset of words. In addition, there are potential clinical applications for reinforcing vocal practice in infant populations who are at risk for poor language skills

Supersymmetric dark matter in M31: can one see neutralino annihilation with CELESTE?

It is widely believed that dark matter exists within galaxies and clusters of galaxies. Under the assumption that this dark matter is composed of the lightest, stable supersymmetric particle, assumed to be the neutralino, the feasibility of its indirect detection via observations of a diffuse gamma-ray signal due to neutralino annihilations within M31 is examined. To this end, first the dark matter halo of the close spiral galaxy M31 is modeled from observations, then the resultant gamma-ray flux is estimated within supersymmetric model configurations. We conclude that under favorable conditions such as the rapid accretion of neutralinos on the central black hole in M31 and/or the presence of many clumps inside its halo with $r^{-3/2}$ inner profiles, a neutralino annihilation gamma-ray signal is marginally detectable by the ongoing collaboration CELESTE.Comment: Latex, 32 pages, 12 figures, 5 table

New Leaders, New Thoughts: Perspectives on Leadership in the 21st Century

Winona State University\u27s Change Leadership graduate course is comprised of seventeen individuals from different generations, with a broad range of skills, backgrounds, and professional expertise. Despite differences, all share a common goal; the desire to become more effective leaders in today’s evolving world. These 21st Century Leaders study, apply basic theory, and develop skills for management and leadership within organizations. Emerging leaders hope to impact the growth, sustainability, and integrity within those organizations. These New Leaders have studied problems and issues influencing individuals and group behavior within organizations to develop collaborative practices, strategies and to empower and advocate for others. New Leaders, New Thoughts is a collection of theory and perspectives on leadership. “There are many issues facing leadership that make studying leadership a must. For example, being able to relay a task, a process, a vision, a mission, or simply transfer daily events all require what many leaders have a difficult time achieving: effective communication.” -Alex Howell This book was created for the fall 2018 Change Leadership course taught by Dr. Barbara Holmes for the WSU Leadership Education Department.https://openriver.winona.edu/leadershipeducationbooks/1002/thumbnail.jp

The Role of Vocal Practice in Constructing Phonological Working Memory

Purpose: In this study, the authors looked for effects of vocal practice on phonological working memory. Method: A longitudinal design was used, combining both naturalistic observations and a nonword repetition test. Fifteen 26-month-olds (12 of whom were followed from age 11 months) were administered a nonword test including real words, "standard" nonwords (identical for all children), and nonwords based on individual children's production inventory (IN and OUT words). Results: A strong relationship was found between (a) length of experience with consonant production and (b) nonword repetition and between (a) differential experience with specific consonants through production and (b) performance on the IN versus OUT words. Conclusions: Performance depended on familiarity with words or their subunits and was strongest for real words, weaker for IN words, and weakest for OUT words. The results demonstrate the important role of speech production in the construction of phonological working memory

Do production patterns influence the processing of speech in prelinguistic infants?

The headturn preference procedure was used to test 18 infants on their response to three different passages chosen to reflect their individual production patterns. The passages contained nonwords with consonants in one of three categories: (a) often produced by that infant (‘own’), (b) rarely produced by that infant but common at that age (‘other’), and (c) not generally produced by infants. Infants who had a single ‘own’ consonant showed no significant preference for either ‘own’ (a) or ‘other’ (b) passages. In contrast, infants’ with two ‘own’ consonants exhibited greater attention to ‘other’ passages (b). Both groups attended equally to the passage featuring consonants rarely produced by infants of that age (c). An analysis of a sample of the infant-directed speech ruled out the mothers’ speech as a source of the infant preferences. The production-based shift to a focus on the ‘other’ passage suggests that nascent production abilities combine with emergent perceptual experience to facilitate word learning