What next?: the German strategy crisis during the summer of 1940

The German blitzkrieg across France during May 1940 was the culmination of three years of daring political and military moves that had brought most of Europe under German control. It was the German dictator Adolf Hitler who had outguessed his advisors. Yet, Hitler\u27s bold moves in Western Europe ended with his army\u27s dash across France, and the failure to strike Great Britain that summer when the British were at one of the weakest points in their entire history. After Germany defeated France, Hitler began a fruitless period of waiting for Great Britain to sue for peace. Unlike Hitler, some in the German High Command believed that Great Britain would fight and that a coherent strategy was needed to defeat that island nation. During late June 1940, two strategies emerged for defeating Great Britain. The first, code-named Operation SEA LION, called for an invasion of southern England. This plan was the surest way to bring about a decisive outcome, but also the riskiest. Hitler nonetheless ordered that planning and training for the operation go forward, a process halted by the Luftwaffe\u27s inability to defeat the RAF as the necessary prelude to the invasion. The strategic option less risky than an invasion of the British Isles called for an attack on the important colony of Gibraltar. German planners believed that seizure of the Rock would place immense stress on the British Empire and possibly force a negotiated peace. In November, German military units were task-organized and trained for the operation, now code-named Operation FELIX. Hitler understood the importance of Gibraltar, but wanted the approval of Francisco Franco, the Spanish dictator, before ordering an attack. Hitler waited. By the spring of 1941, Hitler had failed to act and had lost his opportunity to strike Great Britain when it was most vulnerable. He did not have the will to make the difficult decision and implement either strategy. After December 1940, Great Britain would never again be in danger of an invasion of either the island home or of its valuable colony

Towards improved socio-economic assessments of ocean acidification’s impacts

Ocean acidification is increasingly recognized as a component of global change that could have a wide range of impacts on marine organisms, the ecosystems they live in, and the goods and services they provide humankind. Assessment of these potential socio-economic impacts requires integrated efforts between biologists, chemists, oceanographers, economists and social scientists. But because ocean acidification is a new research area, significant knowledge gaps are preventing economists from estimating its welfare impacts. For instance, economic data on the impact of ocean acidification on significant markets such as fisheries, aquaculture and tourism are very limited (if not non-existent), and non-market valuation studies on this topic are not yet available. Our paper summarizes the current understanding of future OA impacts and sets out what further information is required for economists to assess socio-economic impacts of ocean acidification. Our aim is to provide clear directions for multidisciplinary collaborative research

Therapeutic Use of Bacteriophage and Antibiotic Formulations for the Treatment of Antibiotic Resistant Acinetobacter Baumannii

Gemstone Team LYTICWidespread use of antibiotics has enriched global bacteria populations for strains possessing antibiotic resistance (AR) genes. Proliferation of AR genes and mechanisms have resulted in numerous multidrug resistant (MDR) infections for which there are no effective treatments. Acinetobacter baumannii is a major cause of hospital acquired (nosocomial) infections and is associated with outbreaks of MDR infections. Virulent bacteriophages (phages) present a way to remedy bacterial infections, while also having built-in mechanisms to circumvent resistance. This proposed study aims to develop a phage therapeutic targeting antibiotic resistant A. baumannii. The phages chosen for the final formulation exhibited high bactericidal activity and were able to infect several strains of A. baumannii from a provided library. Additionally, the phage-antibiotic synergy (PAS) effect was investigated in formulations with sub-lethal doses of ampicillin and chloramphenicol. The effectiveness of the phage therapeutic at different multiplicity of infections (MOI) and antibiotic concentrations were assessed relative to standard antibiotic doses. Well-plate studies suggest that higher MOI and antibiotic concentrations resulted in the greatest initial bactericidal effects, longest time to develop resistance, and lowest overall bacteria concentration. In future formulation studies, we would like to expand and optimize the current phage-antibiotic formulation and explore cocktail effects, whereby the formulation consists of a mixture of different phages that increases selective pressure

On two problems in graph Ramsey theory

We study two classical problems in graph Ramsey theory, that of determining the Ramsey number of bounded-degree graphs and that of estimating the induced Ramsey number for a graph with a given number of vertices. The Ramsey number r(H) of a graph H is the least positive integer N such that every two-coloring of the edges of the complete graph $K_N$ contains a monochromatic copy of H. A famous result of Chv\'atal, R\"{o}dl, Szemer\'edi and Trotter states that there exists a constant c(\Delta) such that r(H) \leq c(\Delta) n for every graph H with n vertices and maximum degree \Delta. The important open question is to determine the constant c(\Delta). The best results, both due to Graham, R\"{o}dl and Ruci\'nski, state that there are constants c and c' such that 2^{c' \Delta} \leq c(\Delta) \leq 2^{c \Delta \log^2 \Delta}. We improve this upper bound, showing that there is a constant c for which c(\Delta) \leq 2^{c \Delta \log \Delta}. The induced Ramsey number r_{ind}(H) of a graph H is the least positive integer N for which there exists a graph G on N vertices such that every two-coloring of the edges of G contains an induced monochromatic copy of H. Erd\H{o}s conjectured the existence of a constant c such that, for any graph H on n vertices, r_{ind}(H) \leq 2^{c n}. We move a step closer to proving this conjecture, showing that r_{ind} (H) \leq 2^{c n \log n}. This improves upon an earlier result of Kohayakawa, Pr\"{o}mel and R\"{o}dl by a factor of \log n in the exponent.Comment: 18 page

Exposure of mediterranean countries to ocean acidification

This study examines the potential effects of ocean acidification on countries and fisheries of the Mediterranean Sea. The implications for seafood security and supply are evaluated by examining the sensitivity of the Mediterranean to ocean acidification at chemical, biological, and macro-economic levels. The limited information available on impacts of ocean acidification on harvested (industrial, recreational, and artisanal fishing) and cultured species (aquaculture) prevents any biological impact assessment. However, it appears that non-developed nations around the Mediterranean, particularly those for which fisheries are increasing, yet rely heavily on artisanal fleets, are most greatly exposed to socioeconomic consequences from ocean acidification. © 2014 by the authors; licensee MDPI, Basel, Switzerland

Nutrition and income from molluscs today imply vulnerability to ocean acidification tomorrow

Author Posting. © The Author(s), 2011. This is the author's version of the work. It is posted here by permission of John Wiley & Sons for personal use, not for redistribution. The definitive version was published in Fish and Fisheries 13 (2012): 182-215, doi:10.1111/j.1467-2979.2011.00424.x.Atmospheric carbon dioxide (CO2) emissions from human industrial activities are causing a progressive alteration of seawater chemistry, termed ocean acidification, that has decreased seawater pH and carbonate ion concentration markedly since the Industrial Revolution. Many marine organisms, like molluscs and corals, build hard shells and skeletons using carbonate ions, and they exhibit negative overall responses to ocean acidification. This adds to other chronic and acute environmental pressures and promotes shifts away from calcifierrich communities. In this study, we examine the possible implications of ocean acidification on mollusc harvests worldwide by examining present production, consumption, and export and by relating those data to present and future surface ocean chemistry forecast by a coupled-climate ocean model (Community Climate System 3.1; CCSM3). We identify the “transition decade” when future ocean chemistry will distinctly differ from that of today (2010), and when mollusc harvest levels similar to those of the present cannot be guaranteed if present ocean chemistry is a significant determinant of today’s mollusc production. We assess nations’ vulnerability to ocean acidification-driven decreases in mollusc harvests by comparing nutritional and economic dependences on mollusc harvests, overall societal adaptability, and the amount of time until the transition decade. Projected transition decades for individual countries will occur 10-50 years after 2010. Countries with low adaptability, high nutritional or economic dependence on molluscs, rapidly approaching transition decades, or rapidly growing populations will therefore be most vulnerable to ocean acidification-driven mollusc harvest decreases. These transition decades suggest how soon nations should implement strategies, such as increased aquaculture of resilient species, to help maintain current per capita mollusc harvests.This work was supported in part by National Science Foundation grant ATM-0628582, the Climate and Energy Decision Making (CEDM) Center that is supported under a cooperative agreement with the National Science Foundation (SES-0949710), and the Woods Hole Oceanographic Institution Marine Policy Center

Critical Currents and Vortex States at Fractional Matching Fields in Superconductors with Periodic Pinning

We study vortex states and dynamics in 2D superconductors with periodic pinning at fractional sub-matching fields using numerical simulations. For square pinning arrays we show that ordered states form at 1/1, 1/2, and 1/4 filling fractions while only partially ordered states form at other filling fractions, such as 1/3 and 1/5, in agreement with recent imaging experiments. For triangular pinning arrays we observe matching effects at filling fractions of 1/1, 6/7, 2/3, 1/3, 1/4, 1/6, and 1/7. For both square and triangular pinning arrays we also find that, for certian sub-matching fillings, vortex configurations depend on pinning strength. For weak pinning, ordering in which a portion of the vortices are positioned between pinning sites can occur. Depinning of the vortices at the matching fields, where the vortices are ordered, is elastic while at the incommensurate fields the motion is plastic. At the incommensurate fields, as the applied driving force is increased, there can be a transition to elastic flow where the vortices move along the pinning sites in 1D channels and a reordering transition to a triangular or distorted triangular lattice. We also discuss the current-voltage curves and how they relate to the vortex ordering at commensurate and incommensurate fields.Comment: 14 figure

Natural Mentors, Racial Identity, and Educational Attainment Among African American Adolescents: Exploring Pathways to Success

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/92398/1/j.1467-8624.2012.01769.x.pd

Dark sectors 2016 Workshop: community report

This report, based on the Dark Sectors workshop at SLAC in April 2016, summarizes the scientific importance of searches for dark sector dark matter and forces at masses beneath the weak-scale, the status of this broad international field, the important milestones motivating future exploration, and promising experimental opportunities to reach these milestones over the next 5-10 years

The history of degenerate (bipartite) extremal graph problems

This paper is a survey on Extremal Graph Theory, primarily focusing on the case when one of the excluded graphs is bipartite. On one hand we give an introduction to this field and also describe many important results, methods, problems, and constructions.Comment: 97 pages, 11 figures, many problems. This is the preliminary version of our survey presented in Erdos 100. In this version 2 only a citation was complete