The dark matter halos of the bluest low surface brightness galaxies

We present BVI photometry and long-slit Halpha rotation curve data obtained with ESO VLT/FORS2 for six low surface brightness galaxies with extremely blue colours and very faint central regions. We find no evidence for a steep central density cusp of the type predicted by many N-body simulations of cold dark matter (CDM) halos. Our observations are instead consistent with dark matter halos characterized by cores of roughly constant density, in agreement with previous investigations. While unremarkable in terms of the central density slope, these galaxies appear very challenging for existing CDM halo models in terms of average central halo density, as measured by the Delta_(V/2) parameter. Since most of our target galaxies are bulgeless disks, our observations also disfavour a recently suggested mechanism for lowering the central mass concentration of the halo by means of a fast collapse phase, as this scenario predicts that the original CDM profile should still be detectable in bulgeless galaxies. Other potential ways of reconciling the CDM predictions with these observations are discussed.Comment: 14 pages, 9 figures, accepted for publication in Astronomy & Astrophysic

Prepontine non-giant neurons drive flexible escape behavior in zebrafish

Many species execute ballistic escape reactions to avoid imminent danger. Despite fast reaction times, responses are often highly regulated, reflecting a trade-off between costly motor actions and perceived threat level. However, how sensory cues are integrated within premotor escape circuits remains poorly understood. Here, we show that in zebrafish, less precipitous threats elicit a delayed escape, characterized by flexible trajectories, which are driven by a cluster of 38 prepontine neurons that are completely separate from the fast escape pathway. Whereas neurons that initiate rapid escapes receive direct auditory input and drive motor neurons, input and output pathways for delayed escapes are indirect, facilitating integration of cross-modal sensory information. These results show that rapid decision-making in the escape system is enabled by parallel pathways for ballistic responses and flexible delayed actions and defines a neuronal substrate for hierarchical choice in the vertebrate nervous system

Advanced Communication Theory Techniques TECHNICAL DOCUMENTARY REPORT NO. ASD-TDR-63-186

Under this contract a number of topics have been studied and analyzed in detail in order to bring together and somewhat extend the concepts of communication theory as they apply to some current problems in digital communication systems. Radio wave channels are characterized by a model\u27 which accounts for both multiplicative and additive disturbances, A large amount of experimental data pertaining to radio disturbances is evaluated and correlated. She. importance of the Rayleigh fading channel is emphasized and previous work is extended to determine the capacity and efficiency of the Rayleigh, channel. Detection theory concepts have been extended to treat the problem of signal detection in the presence of statistically unknown additive disturbances. Several detectors based on non-parametric statistical techniques are treated in detail. Obese detectors are compared to the conventional likelihood detectors. Design procedures are formulated. Signal design techniques are used to optimize transmitted wave- forms and the improvement in system performance is determined. The criterion used in this\u27 analysis is the minimization of intersymbol influence and the minimization of transmitter power for a fixed probability of received, errors . The tradeoffs available between transmitter power and coding complexity are thoroughly investigated for the binary symmetric channel. Results are obtained for both Hamming and Bose-Chandhuri codes. Recommendations for further work in promising areas are made, the need to supplement theoretical work with experimental work is pointed ou

One class, two modes of participation: Fully integrating online students into residential classes via web conferencing

What if online and residential students could have an expanded choice of electives, more scheduling options, and greater opportunities for networking with a larger group of peers by offering courses that online and residential students can take together, at the same time? At Columbia University’s School of Social Work, in our Master’s of Science in Social Work program, we are piloting a new type of hybrid course that uses Zoom to bring online students into residential courses. The pilot is an opportunity to figure out how to set up, design, and teach this type of course, and in this poster, we propose to share our lessons learned while we prepared for our courses during the fall semester and have begun to teach during the spring semester. While it is early to evaluate the pilot’s outcomes, we have already learned a great deal about how to plan for technical logistics and how to design engaging class sessions, and the first week of class included breakout discussions in groups that combined online and residential students, as well as whole-class discussions in which both types of students participated equally. We propose to share our work towards the goal of creating one cohesive classroom community rather than two parallel communities or a situation in which the online students simply watched the residential students through a virtual window. We will share our lessons learned around logistics, and considerations for designing lessons plans and assignments that fully integrate the online and residential students, including small-group breakout activities, group presentations, lectures, guest speakers, whole-class discussions, homework assignments, and potentially field trips off campus. This poster will draw from the presenters’ experiences teaching and preparing to teach two Spring 2018 pilot seminar courses: Staff Development, Training, and Coaching, and Managing NGOs

Can online students be fully integrated into residential courses via web conferencing? Lessons learned from two pilot courses at Columbia University -- #OLCAccelerate

ABSTRACT: When online students attend on-campus classes via web conferencing, can they be fully integrated into the classroom community? What challenges does offering two modes of attendance introduce, and how might technology and careful course design offer solutions? This session will offer lessons learned from two pilot courses at Columbia University. EXTENDED ABSTRACT: Institutions that offer both residential and online programs can allow residential students to enroll in online courses; the logistics are relatively simple. However, allowing online students to enroll in residential courses, without requiring them to travel to campus, is more complicated. While this can expand student choices regarding course topics, instructors, and scheduling, as well as build connections between online and residential students, enabling online students to attend residential classes via web conferencing creates challenges. In the literature, in addition to the more common phrasing of telepresence or web conferencing to refer to this type of technology-enhanced communication (Tanaka, Nakanishi, & Ishiguro, 2014; Gleason & Greenhow, 2017), this type of course has also been called gxLearning because the classes are geographically extended (Verhaart & Hagen-Hall, 2012; Day & Verhaart, 2015; Day & Verhaart, 2016), hybrid because the classes include a hybrid blend of on-campus and remote students (Henriksen, Mishra, Greenhow, Cain, & Roseth, 2014), and synchromodal because online and residential students share synchronous sessions via different modes of attendance (Cain, Sawaya, & Bell, 2013; Bell, Sawaya, & Cain, 2014; Bell, Cain, Peterson, & Cheng, 2016; Cain & Bell, 2017). During the workshop, the presenters will share their literature review as a resource for participants who would like to learn more about the research in this area. The bulk of the workshop will focus on sharing lessons learned from planning and teaching two Spring 2018 pilot seminar courses at Columbia University in which online social work students joined residential courses via Zoom web conferencing. The presenters will cover challenges and opportunities when planning residential courses that integrate both online and on-campus students, including: - Logistical concerns that must be addressed prior to the start of the semester, such as student messaging, student registration, classroom setup and technology requirements, and instructor selection and training - Considerations for designing activities and classroom materials that fully engage both online and on-campus students, including during small-group breakout activities, group presentations, and whole-class discussions - Techniques for building one cohesive classroom community, rather than two segregated groups of students - Methods for managing the technology in the physical classroom, or when taking online students along on a field trip off campus The session will include the perspectives of the instructors, TAs, and online students involved in the two pilot courses. Interactivity for the session will include informal hand-raise polls to gauge participants’ experiences and interests around the workshop topic, whole-group discussion questions to give the group the chance to share ideas, pair-share discussions to give participants the chance to consider how they might apply the workshop content to their unique work environments, and time for Q&A. By the end of this workshop, participants should be able to: - Describe the benefits, pedagogical challenges, and logistical concerns that accompany a decision about whether to allow online students who do not live near campus to register for residential courses - Discuss ways to design classroom activities and materials that engage online and residential students with the coursework and with each other as one cohesive classroom community - Share their experiences, tips, concerns, and questions around how to plan, manage, and teach this type of course - Describe the existing literature about this type of course modalit

Efficacy of Online Training for Improving Camp Staff Competency

Preparing competent staff is a critical issue within the camp community. This quasi-experimental study examined the effectiveness of an online course for improving staff competency in camp healthcare practices among college-aged camp staff and a comparison group (N = 55). We hypothesized that working in camp would increase competency test scores due to opportunities for staff to experientially apply knowledge learned online. Hierarchical linear modeling was used to analyse the cross-level effects of a between-individuals factor (assignment to experimental or comparison group) and within-individual effects of time (pre-test, post-test #1, and post-test #2) on online course test scores. At post-test #2, the difference in average test scores between groups was ~30 points, with the treatment group scoring lower on average than the comparison group. Factors that may have influenced these findings are explored, including fatigue and the limited durability of online learning. Recommendations for research and practice are discussed

Karlstadter Positionspapier zum Schutz der Ackerwildkräuter. Erarbeitet von den Teilnehmerinnen und Teilnehmern der "Tagung zum Schutz der Ackerwildflora" am 25./26.6.2004 in Karlstadt am Main

Der Erhalt von Ackerwildkräutern, die historisch erst mit der Landbewirtschaftung in Mitteleuropa heimisch geworden sind, ist eine Kulturaufgabe, damit auch künftige Generationen die Arten- und Farbenvielfalt in der Kulturlandschaft erleben können