Degenerations of Gushel-Mukai fourfolds, with a view towards irrationality proofs

We study a certain class of degenerations of Gushel-Mukai fourfolds as conic bundles, which we call tame degenerations and which are natural if one wants to prove that very general Gushel-Mukai fourfolds are irrational using the degeneration method due to Voisin, Colliot-Th\'{e}l\`{e}ne-Pirutka, Totaro et al. However, we prove that no such tame degenerations do exist.Comment: 25 page

On stable rationality of some conic bundles and moduli spaces of Prym curves

We prove that a very general hypersurface of bidegree (2, n) in P^2 x P^2 for n bigger than or equal to 2 is not stably rational, using Voisin's method of integral Chow-theoretic decompositions of the diagonal and their preservation under mild degenerations. At the same time, we also analyse possible ways to degenerate Prym curves, and the way how various loci inside the moduli space of stable Prym curves are nested. No deformation theory of stacks or sheaves of Azumaya algebras like in recent work of Hasset-Kresch-Tschinkel is used, rather we employ a more elementary and explicit approach via Koszul complexes, which is enough to treat this special case.Comment: 23 pages; Macaulay 2 code used for verification of parts of the paper available at http://www.math.uni-hamburg.de/home/bothmer/m2.html and at the end of the TeX file; v2: in section 4, we now included a proof of the main theorem that works for all n (unconditional on the parity) that was communicated to us by Zhi Jiang, Zhiyu Tian, and Letao Zhang. Several other minor expository improvement

A Self-Evident Lie: Southern Slavery and the Threat to American Freedom

Exploring the Importance of Slavery to American Democracy No single word is as essential to the meaning of the American experience—or as contested—as “equality. Democrats today claim to favor providing as much equality of opportunity as possible; their Republican critics argue that wha...

Youth athlete protection in regard to the European sports charter and the code of ethics

For many youth athletes sport is an enjoyable activity but not for everyone. Some will have their lives destroyed during those years when they are active in sport. Prevention of the abuse that occurs against children and young people is high on the political agenda in many countries in Europe. Until recently, however, this issue has not received much attention in the sporting arena, probably because sport has been associated by most people with fair play, ethical values and high moral standards. In addition, many sport organisations regarded sport as being on the site of political neutrality. Consequently, they have been slow to embrace the principles of equal rights which are enshrined in other public organisations. In this paper, the various forms of abuse and maltreatment that may occur to youth athletes during their participation in sporting activities are demonstrated while focusing on the one side on sexually and on the other side on commercially motivated abuse of the youth athletes. After pointing out the most prevalent and disturbing consequences of youth athletes abuse in sport, the paper deals with the obligation to protect the young athletes. In this context, the role of the Council of Europe and the responsibility of its member states as well as the parents of the young athletes are analysed. The focus however, will be on the responsibility of the sport organisations, who hold control over the sports movement, to implement policies and procedures. At the end, different measures which may help minimising the abuse of youth athletes are introduced. However, it is clear that not the implementation of a single measure alone may offer an effective protection of the youth athletes but an implementation of a combination of various measures on different levels may enhance the possibility of success in fighting the abuse and harassment of youth athletes in sport

Lincoln\u27s Final Hours: Conspiracy, Terror, and the Assassination of America\u27s Greatest President

A Vivid Look at Lincoln’s Final Hours Lincoln\u27s death produced perhaps the saddest days in American history. The fact that Lincoln\u27s assassination came just days after the end of a nearly four-year Civil War added a level of emotional anguish unprecedented in American history. Writing in b...

The Age of Lincoln and the Art of American Power, 1848-1876

Lincoln’s Persuasive Power William Nester\u27s newest book, on how Lincoln and other key leaders from 1848 to 1876 reacted to the crises and opportunities they faced and in so doing decisively shaped American history (7), reminds us why that era remains the public\u27s most popular historical...

Lincoln and Liberty: Wisdom for the Ages

Essays on the Lessons of Lincoln Love of Abraham Lincoln is one thing that both conservatives and liberals each share. Many today, writes Lucas E. Morel in the preface to this informative and often provocative series of essays, are overly preoccupied with the 16th president\u27s openness to ...