EM Cygni: a study of its eclipse timings

EM Cygni is a Z Cam-subtype eclipsing dwarf nova. Its orbital period variations were reported in the past but the results were in conflict to each other while other studies allowed the possibility of no period variation. In this study we report accurate new times of minima of this eclipsing binary and update its O-C diagram. We also estimate the mass transfer rate in EM Cygni system and conclude that the mass transfer is far from the critical value. The mass transfer rate determined from the eclipse timings is in agreement with the spectroscopically determined value.Comment: 5 pages, 4 figures, accepted for publication in Astronomische Nahrichte

Modeling and inference of multisubject fMRI data

Functional magnetic resonance imaging (fMRI) is a rapidly growing technique for studying the brain in action. Since its creation [1], [2], cognitive scientists have been using fMRI to understand how we remember, manipulate, and act on information in our environment. Working with magnetic resonance physicists, statisticians, and engineers, these scientists are pushing the frontiers of knowledge of how the human brain works. The design and analysis of single-subject fMRI studies has been well described. For example, [3], chapters 10 and 11 of [4], and chapters 11 and 14 of [5] all give accessible overviews of fMRI methods for one subject. In contrast, while the appropriate manner to analyze a group of subjects has been the topic of several recent papers, we do not feel it has been covered well in introductory texts and review papers. Therefore, in this article, we bring together old and new work on so-called group modeling of fMRI data using a consistent notation to make the methods more accessible and comparable

Compatible quadratic Poisson brackets related to a family of elliptic curves

We construct nine pairwise compatible quadratic Poisson structures such that a generic linear combination of them is associated with an elliptic algebra in n generators. Explicit formulas for Casimir elements of this elliptic Poisson structure are obtained.Comment: 17 pages, Latex, major change

Moduli spaces of vector bundles over a real curve: Z/2-Betti numbers

Moduli spaces of real bundles over a real curve arise naturally as Lagrangian submanifolds of the moduli space of semi-stable bundles over a complex curve. In this paper, we adapt the methods of Atiyah-Bott's "Yang-Mills over a Riemann Surface" to compute Z/2-Betti numbers of these spaces, proving formulas recently obtained by Liu and Schaffhauser.Comment: 33 pages. Implemented referee suggestions and simplified exposition in the introduction. Comments welcom

Restoration action effectiveness: employing the concept of net ecosystem improvement

The mission statement of the Northwest Straits Initiative includes ‘improving ecosystem health’ of the Strait of Juan de Fuca and Northern Puget Sound by restoring and protecting natural habitats and resources. For the Initiative, and many other programs, defining ‘ecosystem health’ and developing relevant and measureable health metrics is problematic, and yet critical to both assessing program action effectiveness as well as justifying investments. The Initiative is exploring utilizing the concept of net ecosystem improvement (NEI) to summarize results of actions and couch the results in a broader ecosystem perspective. Net improvement is defined as following development; there is an increase in the size and natural functions of an ecosystem or natural components of the ecosystem (Thom et al. 2005. Restoration Ecol. v. 13). Conceptual models are used to summarize knowledge and guide actions to improve the ecosystem. NEI is calculated by estimating the change in function times the change in area over which this change in function occurred including both temporal and spatial aspects. For example, the anchor out zone project managed by the Jefferson County Marine Resources Committee in Port Townsend protects 21.6ha (52 acres) of eelgrass. Without this protection most if not all of the eelgrass would be lost. Using data from other areas, we estimated that 3,998 - 66,077 Dungeness crab (primarily juveniles) and net production by eelgrass of 2,083 metric tons wet wt y-1, are protected. Based on WDNR monitoring (Christiaen et al. 2017), this area of eelgrass protected amounts to 0.5 – 0.8% of the total eelgrass area in the Straits, and 0.5% of the Puget Sound Partnership 2020 eelgrass recovery goal of ~4000ha. Estimating NEI and placing the results in a broader ecosystem perspective is possible for many actions taken by the Initiative’s Marine Resource Committees, and may be appropriate for other programs

A multilevel model for movement rehabilitation in Traumatic Brain Injury (TBI) using virtual environments

This paper presents a conceptual model for movement rehabilitation of traumatic brain injury (TBI) using virtual environments. This hybrid model integrates principles from ecological systems theory with recent advances in cognitive neuroscience, and supports a multilevel approach to both assessment and treatment. Performance outcomes at any stage of recovery are determined by the interplay of task, individual, and environmental/contextual factors. We argue that any system of rehabilitation should provide enough flexibility for task and context factors to be varied systematically, based on the current neuromotor and biomechanical capabilities of the performer or patient. Thus, in order to understand how treatment modalities are to be designed and implemented, there is a need to understand the function of brain systems that support learning at a given stage of recovery, and the inherent plasticity of the system. We know that virtual reality (VR) systems allow training environments to be presented in a highly automated, reliable, and scalable way. Presentation of these virtual environments (VEs) should permit movement analysis at three fundamental levels of behaviour: (i) neurocognitive bases of performance (we focus in particular on the development and use of internal models for action which support adaptive, on-line control); (ii) movement forms and patterns that describe the patients' movement signature at a given stage of recovery (i.e, kinetic and kinematic markers of movement proficiency), (iii) functional outcomes of the movement. Each level of analysis can also map quite seamlessly to different modes of treatment. At the neurocognitive level, for example, semi-immersive VEs can help retrain internal modeling processes by reinforcing the patients' sense of multimodal space (via augmented feedback), their position within it, and the ability to predict and control actions flexibly (via movement simulation and imagery training). More specifically, we derive four - key therapeutic environment concepts (or Elements) presented using VR technologies: Embodiment (simulation and imagery), Spatial Sense (augmenting position sense), Procedural (automaticity and dual-task control), and Participatory (self-initiated action). The use of tangible media/objects, force transduction, and vision-based tracking systems for the augmentation of gestures and physical presence will be discussed in this context

Measures Matter: Scales for Adaptation, Cultural Distance, and Acculturation Orientation Revisited

Building upon existing measures, four new brief acculturation scales are presented, measuring sociocultural adaptation, psychological adaptation, perceived cultural distance, and acculturation orientation. Following good scale reliability in initial samples, the English scales were translated into nine different languages (Chinese, French, German, Italian, Japanese, Portuguese, Spanish, Thai, and Turkish). The translated scales were administered to a large sample of sojourners (N = 1,929), demonstrating good reliability and adequate structural equivalence across languages. In line with existing theory, sociocultural adaptation and psychological adaptation were positively correlated, and showed a negative association with perceived cultural distance. General measures of well-being were correlated with adaptation and distance, with better adaptation relating to higher well-being, and more distance relating to lower well-being. Acculturation orientation toward the home and host culture were measured separately and a weak negative correlation was found between the two, supporting their independence. Arguing against dichotomization, these subscales were analyzed as continuous variables. Regression analysis showed sojourners to be better adapted, if they were oriented more toward the host culture and less toward the home culture. These new scales are proposed as alternatives to existing measures