The GALFA-HI Survey: Data Release 1

We present the Galactic Arecibo L-Band Feed Array HI (GALFA-HI) survey, and its first full data release (DR1). GALFA-HI is a high resolution (~ 4'), large area (13000 deg^2), high spectral resolution (0.18 km/s), wide band (-700 < v_LSR < +700 km/s) survey of the Galactic interstellar medium in the 21-cm line hyperfine transition of neutral hydrogen conducted at Arecibo Observatory. Typical noise levels are 80 mK RMS in an integrated 1 km/s channel. GALFA-HI is a dramatic step forward in high-resolution, large-area Galactic HI surveys, and we compare GALFA-HI to past, present, and future Galactic HI surveys. We describe in detail new techniques we have developed to reduce these data in the presence of fixed pattern noise, gain variation, and inconsistent beam shapes, and we show how we have largely mitigated these effects. We present our first full data release, covering 7520 square degrees of sky and representing 3046 hours of integration time, and discuss the details of these data.Comment: Accepted to the ApJ

Scientific discovery reloaded

The way scientific discovery has been conceptualized has changed drastically in the last few decades: its relation to logic, inference, methods, and evolution has been deeply reloaded. The ‘philosophical matrix’ moulded by logical empiricism and analytical tradition has been challenged by the ‘friends of discovery’, who opened up the way to a rational investigation of discovery. This has produced not only new theories of discovery (like the deductive, cognitive, and evolutionary), but also new ways of practicing it in a rational and more systematic way. Ampliative rules, methods, heuristic procedures and even a logic of discovery have been investigated, extracted, reconstructed and refined. The outcome is a ‘scientific discovery revolution’: not only a new way of looking at discovery, but also a construction of tools that can guide us to discover something new. This is a very important contribution of philosophy of science to science, as it puts the former in a position not only to interpret what scientists do, but also to provide and improve tools that they can employ in their activity

Ongoing Galactic Accretion: Simulations and Observations of Condensed Gas in Hot Halos

Ongoing accretion onto galactic disks has been recently theorized to progress via the unstable cooling of the baryonic halo into condensed clouds. These clouds have been identified as analogous to the High-Velocity Clouds (HVCs) observed in HI in our Galaxy. Here we compare the distribution of HVCs observed around our own Galaxy and extra-planar gas around the Andromeda galaxy to these possible HVC analogs in a simulation of galaxy formation that naturally generates these condensed clouds. We find a very good correspondence between these observations and the simulation, in terms of number, angular size, velocity distribution, overall flux and flux distribution of the clouds. We show that condensed cloud accretion only accounts for ~ 0.2 M_solar / year of the current overall Galactic accretion in the simulations. We also find that the simulated halo clouds accelerate and become more massive as they fall toward the disk. The parameter space of the simulated clouds is consistent with all of the observed HVC complexes that have distance constraints, except the Magellanic Stream which is known to have a different origin. We also find that nearly half of these simulated halo clouds would be indistinguishable from lower-velocity gas and that this effect is strongest further from the disk of the galaxy, thus indicating a possible missing population of HVCs. These results indicate that the majority of HVCs are consistent with being infalling, condensed clouds that are a remnant of Galaxy formation.Comment: 10 pages, 6 figures, ApJ Accepted. Some changes to techniqu

Bilingualism and Self-Perception: Self-Efficacy through the Veil of Two Languages

This chapter is concerned with the relationship between language, as the vehicle of a person’s culture, and self-assessment of one’s capabilities (i.e., self-efficacy) via conventional self-report measures. It relies on the assumption that a language “is ‘a veil’ over the reality of the culture in which it is used, involving an agreement of its users about what there is to be seen and how it should be seen”. Thus, the information weighted and integrated into judgments of one’s self-efficacy is filtered through, and thus it is shaped by cultural schemas which are elicited by the language used to formulate such judgments. Evidence that supports this viewpoint is reviewed

Mesmerizer: A Effective Tool for a Complete Peer-to-Peer Software Development Life-cycle

In this paper we present what are, in our experience, the best practices in Peer-To-Peer(P2P) application development and how we combined them in a middleware platform called Mesmerizer. We explain how simulation is an integral part of the development process and not just an assessment tool. We then present our component-based event-driven framework for P2P application development, which can be used to execute multiple instances of the same application in a strictly controlled manner over an emulated network layer for simulation/testing, or a single application in a concurrent environment for deployment purpose. We highlight modeling aspects that are of critical importance for designing and testing P2P applications, e.g. the emulation of Network Address Translation and bandwidth dynamics. We show how our simulator scales when emulating low-level bandwidth characteristics of thousands of concurrent peers while preserving a good degree of accuracy compared to a packet-level simulator

Explicit code-switching instruction in writing for young adolescents speaking African American English

This study examined the effects of explicit and systematic code-switching or dialect-shifting instruction on a writing performance of a sixth grade student speaking African American English. Intervention included code-switching or teaching when a certain language variety is appropriate, a side-by-side contrasting of the features of African American English(AAE) and Standard American English, and sentence “translations” from one dialect into another one (Wheeler & Swords, 2008). The intervention was delivered to the subject over the course of nine 60-minute sessions. Writing samples were collected throughout the sessions and were analyzed for the number of features of African American English to monitor the subject\u27s progress. The findings of the study indicated that explicit code-switching instruction in subject-verb agreement made a positive effect on the student\u27s writing. While other features of AAE were present in her post-intervention writing sample, they were not sufficiently addressed in the intervention and can serve as a starting point for future studies

Introduction to Lexical Borrowing and Deborrowing in Spanish in New York City

Lexical Borrowing and Deborrowing in Spanish in New York City provides a sociodemographic portrait of lexical borrowing in Spanish in New York City. The volume offers new and important insights into research on lexical borrowing. In particular, it presents empirical data obtained through quantitative analysis to answer the question of who is most likely to use English lexical borrowings while speaking Spanish, to address the impact that English has on Spanish as spoken in the city and to identify the social factors that contribute to language change. The book also provides an empirical, corpus-based-approach to distinguishing between borrowing and other contact phenomena, such as codeswitching, which will be of interest to scholars of language contact and bilingualism.https://scholarworks.wm.edu/asbookchapters/1125/thumbnail.jp