Nothing is forever: boom and bust in Midwest farming

Agriculture - North Central states ; Federal Reserve District, 7th

Accelerated motion and the self-force in Schwarzschild spacetime

We provide expansions of the Detweiler-Whiting singular field for motion along arbitrary, planar accelerated trajectories in Schwarzschild spacetime. We transcribe these results into mode-sum regularization parameters, computing previously unknown terms that increase the convergence rate of the mode-sum. We test our results by computing the self-force along a variety of accelerated trajectories. For non-uniformly accelerated circular orbits we present results from a new 1+1D discontinuous Galerkin time-domain code which employs an effective-source. We also present results for uniformly accelerated circular orbits and accelerated bound eccentric orbits computed within a frequency-domain treatment. Our regularization results will be useful for computing self-consistent self-force inspirals where the particle's worldline is accelerated with respect to the background spacetime.Comment: 19 pages, 6 figures (accepted CQG special issue article version

Preliminary Observations on Oyster Pearl Net Cultivation in Coastal Georgia

This work reports on survivorship and growth rates attained by a transplanted northern stock of Crassostrea virginica (x̄ = 15 mm) tested at various densities in pearl nets in sheltered and exposed sites in coastal Georgia (October 1985 - August 1986). Monthly growth increments ranged from 4.5 to 5.1 mm (shell height). One hundred oysters per net was the optimum stocking density. One hundred percent mortality was suffered at both sites during June - August (probably due to Perkinsus marinus). Current growth rates indicate a growth to market size time of 18 months or less for 15 mm seed grown in pearl nets. However, pearl net cultivation is shown to have serious drawbacks as an oyster grow-out system for coastal Georgia and alternative systems are discussed

The Effects of Cage Mesh Size and Tidal Level Placement on the Growth and Survival of Clams, Mercenaria mercenaria (L.) and Spisula solidissima (Dillwyn), in the Coastal Waters of Georgia

This work reports on the effects of cage mesh size and tidal level placement upon the growth and survival of the hard clam, Mercenarla mercenaria (L.), and the surf clam, Spisula solidissima (Dillwyn), In the coastal waters of Georgia. Surf clams (N = 50 per cage) and hard clams (N = 100 per cage) were each planted in replicated (N = 2) cages constructed of 3 mm, 6 mm, 13 mm and 19 mm mesh vexar plastic at various tidal levels. Cages were deployed by partial burial at the mean and the spring low water marks. At termination of the surf clam trial (6 months), there were no significant differences in survival determined for clams planted in different mesh cages at either tidal level or for clams grown in equivalent mesh size cages between tidal levels. There were significant differences In clam size with surf clams at the spring low water growing significantly larger than those at the mean low water mark. There were also significant differences In surf clam growth between different mesh size cages. Surf clams from 6 mm cages were smaller than those from other cages, while the largest clams reared were in the 13 mm and 19 mm mesh cages. Hard clam trials (15 month duration) illustrated that cage mesh size induced significant differences in survlval of hard clams. Significantly fewer clams survived In 19 mm mesh cages than in cages of smaller mesh at both tidal levels. No significant differences in hard clam survival were detected among other mesh sizes nor between tidal levels; neither were significant differences between tidal levels determined for equivalent mesh sizes. Significant differences in hard clam growth were determined for clams grown in different mesh size cages and between tidal levels. Clam growth was greater at the spring low water mark. Clams grew larger in 3 mm mesh cages, least In 13 mm mesh cages with no significant differences In growth in the 6 and 19 mm mesh cages. Statistical analyses (t-tests) Illustrated differences in clam growth among replicates at the spring low water mark. Growth may have been reduced in one set of cages as a result of cage excavation by currents. In Georgia, hard and surf clam growth was found to be dependent upon cage mesh size. Clam survival was Independent of cage mesh size as long as the initial size of the seed animals was greater than the mesh size of the cage

Fighting for the Right to Housing in Canada

This paper examines Tanudjaja v Attorney General—the “Right to Housing” case. The authors, co-counsel on the case, discuss the context of the case, the nature of the application, and the legal underpinnings of the section 7 and 15 Canadian Charter of Rights and Freedoms claims, including positive obligations under the Charter and international law, innovative procedure taking a systemic approach to challenging oppressive legislation, and innovative supervisory orders. The authors examine the procedural and substantive implications of the provincial and federal governments’ move to strike the case, parse the Ontario Superior Court of Justice and Ontario Court of Appeal decisions striking the application, and analyze the impact these decisions may have for future Charter litigants. They also address the relationship between community organizing and litigating rights of marginalized communities

Fighting for the Right to Housing in Canada

This paper examines Tanudjaja v Attorney General—the “Right to Housing” case. The authors, co-counsel on the case, discuss the context of the case, the nature of the application, and the legal underpinnings of the section 7 and 15 Canadian Charter of Rights and Freedoms claims, including positive obligations under the Charter and international law, innovative procedure taking a systemic approach to challenging oppressive legislation, and innovative supervisory orders. The authors examine the procedural and substantive implications of the provincial and federal governments’ move to strike the case, parse the Ontario Superior Court of Justice and Ontario Court of Appeal decisions striking the application, and analyze the impact these decisions may have for future Charter litigants. They also address the relationship between community organizing and litigating rights of marginalized communities

TPACK as shared practice: toward a research agenda

The task of using Information and Communication Technologies (ICT) to effectively teach hundreds of pre-service educators, many of whom never attend campus, is a significant challenge, which is amplified by the need to do so in ways that model how they might use ICT in their own classrooms once they graduate. This paper analyses a collection of posts written across a teaching year on a group blog by three teacher educators as they explored their practice and attempted to learn how to meet this challenge. The analysis uses a distributed view of knowledge and learning to identify the barriers and enablers encountered, and how the teacher educators developed their distributed TPACK throughout the year. The paper argues that a distributed view of TPACK offers some interesting insights that can inform practitioners, researchers and policy makers as they explore practice and learn how to meet the technology integration challenge

Lethal Parasites in Oysters from Coastal Georgia with Discussion of Disease and Management Implications

Extensive mortalities of oysters, Crassostrea virginica, occurred from 1985 through 1987 in coastal waters of Georgia. Fluid thioglycolate cultures of oysters collected from 16 of 17 locations revealed infections by the apicomplexan parasite Perkinsus marinus. An ascetosporan parasite, Haplosporidium nelsoni, was also observed in histopathological examination of oysters from 4 of the locations. While the range of H. nelsoni currently is recognized as the east coast of the United States from Maine to Florida, this is the first report of the parasite in Georgia waters. This paper documents the occurrence of these two lethal parasites in oysters from coastal waters of Georgia, along with potential disease and management implications. Results of an earlier independent and previously unpublished survey are also discussed which document the presence of P. marinus in Georgia as early as 1966

Mobilities of knowledge: an introduction

Mobilities of Knowledge examines how geographical mobility of people and (im)material things has impacted epistemic systems of knowledge in different historical and geographical contexts. In this chapter, the authors introduce concepts and debates in interdisciplinary research on spatial mobility and the production, dissemination, and transfer of knowledge. They suggest extending Urry’s (2007) typology of interdependent mobilities that constitute the space of flows and the space of places (Castells, 1996) from five to six dimensions through the consideration of mobile knowledges, concepts, and practices. Finally, they outline how the chapters of this volume help to identify generic as well as context-specific practices and processes of knowledge production, dissemination, and transfer and call for more empirical case studies to further the collective development of flexible conceptual understandings

Mapping the digital practices of teacher educators: implications for teacher education in changing digital landscapes

Almost 40 years since the first personal computers appeared in classrooms. Education is still awaiting transformation on the scale experienced in other parts of society. The replacement of digital immigrant teachers by a younger generation of digital natives has not made the anticipated difference. That metaphor is discredited and new perspectives are needed. In this paper the metaphor of digital visitors and residents is adapted to support examination and mapping of the digital practices of teacher educators according to the traces they leave in the digital landscape and levels of modification to tools as supplied. Questions are asked about the degree to which teachers and teacher educators need to modify tools or create their own in order to better adapt ICT in support of learning and teaching