Streamer branching rationalized by conformal mapping techniques

Spontaneous branching of discharge channels is frequently observed, but not well understood. We recently proposed a new branching mechanism based on simulations of a simple continuous discharge model in high fields. We here present analytical results for such streamers in the Lozansky-Firsov limit where they can be modelled as moving equipotential ionization fronts. This model can be analyzed by conformal mapping techniques which allow the reduction of the dynamical problem to finite sets of nonlinear ordinary differential equations. The solutions illustrate that branching is generic for the intricate head dynamics of streamers in the Lozansky-Firsov-limit.Comment: 4 pages, 2 figure

Fractional Calculus as a Macroscopic Manifestation of Randomness

We generalize the method of Van Hove so as to deal with the case of non-ordinary statistical mechanics, that being phenomena with no time-scale separation. We show that in the case of ordinary statistical mechanics, even if the adoption of the Van Hove method imposes randomness upon Hamiltonian dynamics, the resulting statistical process is described using normal calculus techniques. On the other hand, in the case where there is no time-scale separation, this generalized version of Van Hove's method not only imposes randomness upon the microscopic dynamics, but it also transmits randomness to the macroscopic level. As a result, the correct description of macroscopic dynamics has to be expressed in terms of the fractional calculus.Comment: 20 pages, 1 figur

Whose Job Is It Anyway? Preparing Arbitrators for Consumer Dispute Resolution Programs

[Excerpt] In many respects, we have entered into a golden era in the evolution and study of conflict resolution. One of the most obvious examples of this new era is the significant growth of conflict resolution programs in institutions of higher education. The purpose of this article is to examine the current state of university and law school conflict resolution programs. We then offer some conclusions and recommendations for addressing what we believe to be the critically important role academia can and should play in training arbitrators. Our review of academic programs suggests that the array of offerings has grown substantially and includes credit courses, clinics, degree programs, and certificates in conflict resolution. At our own institution, Cornell University, the response by our student body to opportunities for studying conflict resolution has overwhelmed our current capacity to meet their needs and interests

Helicobacter pylori infection and gastric dysbiosis: Can probiotics administration be useful to treat this condition?

Helicobacter pylori (Hp) is responsible for one of the most common infections in the world. 'e prevalence exceeds 50% of the population in developing countries, and approximately one-third of the adults are colonized in North Europe and North America. It is considered a major pathogenic agent of chronic gastritis, peptic ulcer, atrophic gastritis, gastric cancer, and mucosa-associated lymphoid tissue lymphoma (MALT). Hp colonization modifies the composition of gastric microbiota that could drive the development of gastric disorders. Currently, an emerging problem in Hp treatment is represented by the increasing rate of antimicrobial therapy resistance. In this context, the search for adjuvant agents can be very useful to overcome this issue and probiotics administration can represent a valid option. The aim of this review is to describe the gastric microbiota changes during Hp colonization, the mechanisms of action, and a possible role of probiotics in the treatment of this infection

High-frequency cyclicity in the Mediterranean Messinian evaporites: evidence for solar-lunar climate forcing

The deposition of varved sedimentary sequences is usually controlled by climate conditions. The study of two Late Miocene evaporite successions (one halite and the other gypsum) consisting of annual varves has been carried out to reconstruct the paleoclimatic and paleoenvironmental conditions existing during the acme of the Messinian salinity crisis, ~ 6 Ma, when thick evaporite deposits accumulated on the floor of the Mediterranean basin. Spectral analyses of these varved evaporitic successions reveal significant periodicity peaks at around 3-5, 9, 11-13, 20-27 and 50-100 yr. A comparison with modern precipitation data in the western Mediterranean shows that during the acme of the Messinian salinity crisis the climate was not in a permanent evaporitic stage, but in a dynamic situation where evaporite deposition was controlled by quasi-periodic climate oscillations with similarity to modern analogs including Quasi-Biennial Oscillation, El Ni\~no Southern Oscillation, and decadal to secular lunar- and solar-induced cycles. Particularly we found a significant quasi-decadal oscillation with a prominent 9-year peak that is commonly found also in modern temperature records and is present in the contemporary Atlantic Multidecadal Oscillation (AMO) index and Pacific Decadal Oscillation (PDO) index. These cyclicities are common to both ancient and modern climate records because they can be associated with solar and solar-lunar tidal cycles.Comment: 13 pages, 10 figures, 1 Tabl

Introduction: An Unsettled Time from \u3cem\u3eAmerican Political Development and the Trump Presidency\u3c/em\u3e

As the words of his inaugural address echoed across a rain- soaked National Mall, Donald Trump cut a hole in time. His presidency, he said, marked a breaking point in American politics. No longer would a “small group” of elites reap the benefits of government while “forgotten Americans” bore the cost. “Now,” Trump suggested, “we are only looking to the future.” Even so, the speech telegraphed a dystopian pre sent; the United States had become a landscape of rusted- out factories, cities teeming with crime, and national borders defenseless against terrorist threats. Gone was the promised land that Trump’s predecessors foretold in their inaugural speeches, the “city on a hill” that America was destined to be. Trump identified few, if any, sources of political possibility. America would be “made great again” not through providence, but by Trump himself: “I will fight for you with every breath in my body— and I will never, ever let you down.” Rather than binding the nation through conciliation and compromise, Trump promised nationalism: “The bedrock of our politics,” he said, “will be a total allegiance to the United States of America.” He labeled his foreign policy with a phrase burdened with an isolationist and anti- Semitic history: “America First.” ..