The Lyot Project Direct Imaging Survey of Substellar Companions: Statistical Analysis and Information from Nondetections

The Lyot project used an optimized Lyot coronagraph with Extreme Adaptive Optics at the 3.63m Advanced Electro-Optical System telescope (AEOS) to observe 86 stars from 2004 to 2007. In this paper we give an overview of the survey results and a statistical analysis of the observed nondetections around 58 of our targets to place constraints on the population of substellar companions to nearby stars. The observations did not detect any companion in the substellar regime. Since null results can be as important as detections, we analyzed each observation to determine the characteristics of the companions that can be ruled out. For this purpose we use a Monte Carlo approach to produce artificial companions, and determine their detectability by comparison with the sensitivity curve for each star. All the non-detection results are combined using a Bayesian approach and we provide upper limits on the population of giant exoplanets and brown dwarfs for this sample of stars. Our nondetections confirm the rarity of brown dwarfs around solar-like stars and we constrain the frequency of massive substellar companions (M>40Mjup) at orbital separation between and 10 and 50 AU to be <20%.Comment: 32 pages, 11 figures, 2 tables. Published in the Astrophysical Journa

Development of a Coherent Doppler Lidar for Precision Maneuvering and Landing of Space Vehicles

A coherent Doppler lidar has been developed to address NASAs need for a high-performance, compact, and cost-effective velocity and altitude sensor onboard its landing vehicles. Future robotic and manned missions to planetary bodies require precise ground-relative velocity vector and altitude data to execute complex descent maneuvers and safe, soft landing at a pre-designated site. This lidar sensor, referred to as a Navigation Doppler Lidar, meets the required performance of landing missions while complying with vehicle size, mass, and power constraints. Operating from over five kilometers altitude, the lidar obtains velocity and range precision measurements with 2 cm/sec and 2 meters, respectively, dominated by the vehicle motion. After a series of flight tests onboard helicopters and rocket-powered free-flyer vehicles, the Navigation Doppler Lidar is now being ruggedized for future missions to various destinations in the solar system

A Comparison of Fish Communities in Southwestern Lake Ontario Tributaries From One Century Ago

I evaluated a study performed by Albert Hazen Wright between 1902 and 1904, on the Tributaries of Lake Ontario in Monroe County, NY. I extracted data from Wright\u27s original graphical analysis, and analyzed these data with Canonical Correspondence Analysis (CCA), to assess the value of these data for use as historical benchmarks for future studies on the same tributaries. Wright identified 52 species of fish within his distribution diagrams, eight of the species were rare species and were not analyzed with the CCA. Of the 44 remaining species analyzed, 37 matched very well between Wright\u27s interpretations of his data, and the results of my analysis. Six species were a partial match, and one, the Tessellated Darter (Etheostoma olmstedi), was considered a subspecies and was not interpreted by Wright. Overall, Wright\u27s interpretations matched well with my analysis of his data, and corresponded well with current understandings of the species x species and species x habitat relationships within a stream continuum from more recent studies. Wright\u27s data set and interpretations proved to be accurate, and a valuable historical reference. I then examined these same tributaries for current fish populations, using a point-transect methodology and a combination of haul seine and dip nets to sample each macro-habitat (pool, riffle, run) present at each site. I found a total of 34 species of fish, three fewer than Wright\u27s 37 species, within the same segments of these streams. Of the 34 species I found, eight were species Wright did not find. Introductions of native and non-native invasive species appeared to greatly influence the habitat associations of some species. I found that the habitat parameters river mile, depth, width and vegetation, had the greatest influence on fish distribution

'A Metamorphosed Language': Tracing Language Attitudes Towards Lubumbashi Swahili and French in the DRC

Language attitudes in Lubumbashi, and particularly towards Lubumbashi Swahili and French, are not only indicative of positive, negative, and ambivalent feelings towards vocabulary or syntax, but of larger socio-historical and current developments, too. These attitudes, however, have not been explicitly researched. This paper seeks to begin filling that void, examining three intertwined hypotheses grounded in the language attitudes seen across Sub-Saharan Africa: (1) languages have historically been regarded ambivalently, and will continue to be held in such regard, but also that; (2) Lubumbashi Swahili has become an indispensable tool for survival in the city and that; (3) French remains an important tool for social mobility. Building off the limited scholarship on historic attitudes, my fieldwork conducted in Lubumbashi in July 2022 confirms these hypotheses, giving a fuller indication of how locals and settlers felt and continue to feel about languages as they relate to the now modernised society of Lubumbashi

Microfascism in the 21st Century: Finding a Way Forward through Deleuze’s Immanent Theory of Desire

This paper takes a critical examination at selected works by 20th century philosophers Gilles Deleuze and Félix Guattari. I argue that, far from arcane, distant, inaccessible concepts, the selected Marxist ideas presented in their immanent critiques provide priceless insight into how fascism, in all forms, permeates every stretch of society. Understanding how these events occur, called micro- and macro-fascism, and how they are mediated through our beliefs and desires, can allow for us to resist transcendent theories of desire and modes and politics, and towards a mode of immanence, one that is always critiquing itself, and always resisting fascism

Exhibition review: Black Atlantic: power, people, resistance

A content warning states at several points throughout the exhibition: ‘This exhibition explores themes of enslavement and racism. It includes depictions of slavery and objects linked to violence and exploitation’. This review does as well.The Fitzwilliam Museum has skillfully delivered its most important exhibition to date: Black Atlantic: power, people, resistance (hereafter Black Atlantic). It is a triumph of curatorial collaboration and expert research, carefully crafted into a narrative that disrupts our historical understanding of Richard Fitzwilliam, the founding of the Museum, and our perceptions of European visual culture in the complicity of perpetuating and justifying the transatlantic enslavement of African peoples

''A Metamorphosed Language": Tracing Language Attitudes Towards Lubumbashi Swahili and French in the DRC

Language attitudes in Lubumbashi, and particularly towards Lubumbashi Swahili and French, are not only indicative of positive, negative, and ambivalent feelings towards vocabulary or syntax, but of larger socio-historical and current developments, too. These attitudes, however, have not been explicitly researched. This paper seeks to begin filling that void, examining three intertwined hypotheses grounded in the language attitudes seen across Sub-Saharan Africa: (1) languages have historically been regarded ambivalently, and will continue to be held in such regard, but also that; (2) Lubumbashi Swahili has become an indispensable tool for survival in the city and that; (3) French remains an important tool for social mobility. Building off the limited scholarship on historic attitudes, my fieldwork conducted in Lubumbashi in July 2022 confirms these hypotheses, giving a fuller indication of how locals and settlers felt and continue to feel about languages as they relate to the now modernised society of Lubumbashi