On The Performance Characteristics Of Electron Ring accelerators

On the basis of our present understanding of the physical phenomena involved in an electron ring accelerator (ERA), a theoretical study is made of the performance which might be expected for an ERA. Rigorous upper bounds are obtained on the rate of energy gain, from which it is shown that, in order to prevent azimuthal instability, parameters must be selected such that (for reasonable fields, injector properties, etc., but with no safety factors) the proton energy gain is less than 80 MeV/m. Numerical examples and approximate formulas are given for the properties of rings satisfying the stability conditions for both azimuthal oscillations and ion-electron oscillations. It is found that for reasonable fields and injector properties, but without safety factors, the useable proton energy gain is less than 45 MeV/m

On the Edge: Blacks and Hispanics in Metropolitan Miami Since 1959

On Monday, January 16, 1989, hundreds of blacks in Miami took to the streets in angry rage for the fourth time in the 1980s. Over several days, they burned cars and buildings, looted stores, pelted passers-by with rocks and bottles, and faced off with riot police in Overtown and Liberty City, Miami’s two major black communities. The incident that touched off this new expression of black anger was sadly familiar. A Miami policeman had shot and killed a black man fleeing a traffic infraction on a motorcycle, while a second black man, a passenger on the motorcycle, was thrown from the vehicle and also killed. It was difficult to miss the irony in the fact that this latest Miami riot took place on the same day that blacks had celebrated the birthday of Martin Luther King, Jr., the modern apostle of nonviolence. There were other ironies, as well. In this new immigrant city, it should not have been surprising that none of those involved in the riot-triggering incident was a native-born American. The police officer who fired the fatal bullet, William Lozano, had immigrated to Miami with his family from Colombia. Although few noticed at the time, the two dead black men, Allen Blanchard and Clement Lloyd, were also migrants from the Carribean basin, from the U. S. Virgin Islands. The three newcomers whose paths crossed on that fateful Monday evening had come to south Florida in search of the elusive American dream; what they found in Miami, ultimately, was something quite different

Whitening Miami: Race, Housing, and Government Policy in Twentieth-Century Dade County

Throughout the twentieth century, government agencies played a powerful role in creating and sustaining racially separate and segregated housing in Dade County, Florida. This pattern of housing segregation initially was imposed early through official policies of racial zoning, During the New Deal era of lhe 1930s, federal housing policies were implemented at the local level to maintain legally segregated housing and neighborhoods. Such policies included the appraisal system established by the federal Home Owners Loan Corporation, which helped to create the discriminatory lending system known as redlining. In addition, under the New Deal\u27s federally sponsored public housing program, local housing authorities established segregated public housing projects. In the post-World War II years, old agendas for racial segregation continued to be carried out under still newer government programs, including the minority housing programs of the Housing and Home Finance Agency, the urban redevelopment and urban renewal programs of the federal housing acts of 1949 and 1954, and the vast interstate highway program. Local decision-making and implementation of all these programs perpetuated the racial segregation of Dade County neighborhoods and public housing projects

Review Essay:--The Transformation of the Late-Twentieth-Century South

Over the past few decades, the study of southern history has experienced an impressive scholarly renewal. Few areas of modern American scholarship have produced such exciting new work. Traditional subjects such as the antebellum South, the Civil War and Reconstruction, and post-Reconstruction southern politics and race relations have been reworked and reinterpreted. Recent social and cultural history approaches have given us new perspectives on slavery and slaves, the white and black working class, black and white women, urban and rural life, family and religion, and the cultural imperatives that shaped and molded the southern experience. Above all, however, southern historical scholarship has moved solidly into the twentieth century. This outpouring of work on the modern South— on southern politics, on race relations, on civil rights, on rural and urban change, and on many other subjects— has made possible Numan V. Bartley’s compelling synthesis, The New South, 1945-1980, the eleventh volume in Louisiana State University Press’s distinguished History of the South series

The Acidic Tail of the Cdc34 Ubiquitin-conjugating Enzyme Functions in Both Binding to and Catalysis with Ubiquitin Ligase SCFC^(dc4*)

Ubiquitin ligases, together with their cognate ubiquitin-conjugating enzymes, are responsible for the ubiquitylation of proteins, a process that regulates a myriad of eukaryotic cellular functions. The first cullin-RING ligase discovered, yeast SCF^(Cdc4), functions with the conjugating enzyme Cdc34 to regulate the cell cycle. Cdc34 orthologs are notable for their highly acidic C-terminal extension. Here we confirm that the Cdc34 acidic C-terminal tail has a role in Cdc34 binding to SCF^(Cdc4) and makes a major contribution to the submicromolar K_m of Cdc34 for SCF^(Cdc4). Moreover, we demonstrate that a key functional property of the tail is its acidity. Our analysis also uncovers an unexpected new function for the acidic tail in promoting catalysis. We demonstrate that SCF is functional when Cdc34 is fused to the C terminus of Cul1 and that this fusion retains partial function even when the acidic tail has been deleted. The Cdc34-SCF fusion proteins that lack the acidic tail must interact in a fundamentally different manner than unfused SCF and wild type Cdc34, demonstrating that distinct mechanisms of E2 recruitment to E3, as is seen in nature, can sustain substrate ubiquitylation. Finally, a search of the yeast proteome uncovered scores of proteins containing highly acidic stretches of amino acids, hinting that electrostatic interactions may be a common mechanism for facilitating protein assembly

CDK-dependent nuclear localization of B-Cyclin Clb1 promotes FEAR activation during meiosis I in budding yeast

Cyclin-dependent kinases (CDK) are master regulators of the cell cycle in eukaryotes. CDK activity is regulated by the presence, post-translational modification and spatial localization of its regulatory subunit cyclin. In budding yeast, the B-cyclin Clb1 is phosphorylated and localizes to the nucleus during meiosis I. However the functional significance of Clb1's phosphorylation and nuclear localization and their mutual dependency is unknown. In this paper, we demonstrate that meiosis-specific phosphorylation of Clb1 requires its import to the nucleus but not vice versa. While Clb1 phosphorylation is dependent on activity of both CDK and polo-like kinase Cdc5, its nuclear localization requires CDK but not Cdc5 activity. Furthermore we show that increased nuclear localization of Clb1 during meiosis enhances activation of FEAR (Cdc Fourteen Early Anaphase Release) pathway. We discuss the significance of our results in relation to regulation of exit from meiosis I

News Accuracy in Switzerland and Italy

Nearly 80 years of accuracy research in the United States has documented that the press frequently errs, but empirical study about news accuracy elsewhere in the world is absent. This article presents an accuracy audit of Swiss and Italian daily regional newspapers. Replicating US research, the study offers a trans-Atlantic perspective of news accuracy. To compare newspaper accuracy in Switzerland and Italy to longitudinal accuracy research in the United States, the study followed closely the methodology pioneered by Charnley (1936) and adapted by Maier (2005). News sources found factual inaccuracy in 60 percent of Swiss newspaper stories they reviewed, compared to 48 percent of US and 52 percent of Italian newspapers examined. The results show that newspaper inaccuracy—and its corrosive effect on media credibility—transcends national borders and journalism cultures. Nowadays, digitization offers new ways of implementing correction policies. Media organizations need, however, to adapt to these changes and to adapt their structures in particular to new forms of participative and interactive two-way communication

Does Involvement in Healthy Eating Among University Students Differ Based on Exercise Status and Reasons for Exercise?

Background. Unhealthy nutritional habits are a major cause of morbidity and mortality in the US. Research indicates that regular physical activity can influence dietary habits of adults. Purpose. The purpose of this study was to examine whether university students’ involvement in healthy eating differed based on current exercise status and reported reasons for exercising. Methods. A sample of 204 university students completed a 22-item survey on healthy eating and physical activity. Results. Less than 10% met all Food Guide recommendations. The leading barriers to healthy eating were time, convenience and healthy food availability. Less than half exercised on four or more days each week. The leading reasons for exercising were to improve appearance, improve health and lose weight. Being physically active did not have a significant effect on healthy eating, nor did specific reason for exercising. Discussion. Most students did not eat healthy and their physical activity levels did not significantly affect their nutritional habits. Increased awareness campaigns are warranted. Conclusions. Strategies other than physical activity promotion are needed to positively impact students’ healthy eating behaviors. Students should continue to be educated about healthy nutrition and ways to reduce perceived barriers to healthy eating