Coherent instabilities of intense high-energy "white" charged-particle beams in the presence of nonlocal effects within the context of the Madelung fluid description

A hydrodynamical description of coherent instabilities that take place in the longitudinal dynamics of a charged-particle coasting beam in a high-energy accelerating machine is presented. This is done in the framework of the Madelung fluid picture provided by the Thermal Wave Model. The well known coherent instability charts in the complex plane of the longitudinal coupling impedance for monochromatic beams are recovered. The results are also interpreted in terms of the deterministic approach to modulational instability analysis usually given for monochromatic large amplitude wave train propagation governed by the nonlinear Schr\"odinger equation. The instability analysis is then extended to a non-monochromatic coasting beam with a given thermal equilibrium distribution, thought as a statistical ensemble of monochromatic incoherent coasting beams ("white" beam). In this hydrodynamical framework, the phenomenon of Landau damping is predicted without using any kinetic equation governing the phase space evolution of the system.Comment: 14 pages, 1 figur

Evaluating Ecosystem Investments

This report focuses on what was learned about best practices for evaluating the effects of ecosystem investments along with examples of how others are using these practicesin their work.MethodologyThree research questions guided this engagement:What are the new / best practices in evaluating the effects of ecosystem invest­ments?Which organizations are evaluating these investments well? What can they teach us?What relevant outcomes and indicators could Omidyar Network use to evaluate its ecosystem investments?To answer these questions, FSG conducted the following activities, in addition to drawing on our experience supporting strategic learning and evaluation in complex environments. Appendix A includes a complete list of grants reviewed and interviewees.Grants analysis: FSG analyzed Omidyar Network's Initiative Results Architecture frameworks and 23 grants within its ecosystem investment portfolio. These docu­ments helped ground our research in an understanding of the different types of ecosystem investments Omidyar Network is making, as well as how the organiza­tion currently evaluates the impact of its ecosystem investments.Literature review: FSG reviewed more than 60 publications to identify best practices in evaluating ecosystem investments—these publications included both peer-reviewed journal articles and "grey literature" (conference presentations, blog posts) by organizations employing advocacy-type strategies.Interviews: FSG conducted interviews with nine external experts (listed in Appen­dix A) to more deeply understand effective practices in evaluating the effects of eco­system investments and to identify leading organizations in this area. Interviewees were identified to glean best practices from both within and outside the traditional social sector

Evaluation of Performance and Efficiency of Polish Open-End Mutual Funds under High Volatility Environment in Financial Markets

Theoretical background: Retail investors in the financial market have nowadays access to a wide range of investment products. One of the types of such products are open-end investment funds, which by design are asset masses managed by professional entities. Open-end investment funds became one of the more popular financial instruments that retail customers purchase.Purpose of the article: This article aims at determining the efficiency of mutual funds as measured by the rate of return. An important point of the study is to determine whether funds with lower total risk as measured by standard deviation achieved lower losses.Research methods: The research method is an analysis of performance of twenty Polish open-ended mutual funds in three different time horizons, by using classic mutual fund performance measures adjusted for negative returns, i.e. Sharpe, Treynor and Jensen alpha indicators as well as the Israelsen and Treynor ratios adjusted for negative return.Main findings: It has been observed that the high volatility in the financial market had a direct negative impact on the returns of these funds. When comparing the Treynor ratio adjusted for negative returns values it appears that some of the analysed equity funds performed better than, for example, stable growth funds. In case of high volatility in the stock market, both in the long and short term, the analysed stable growth funds did not bring more value to investors in relation to the total risk incurred than balanced or even equity funds, which is particularly noticeable in the case of three-year and annual results. This is because asset diversification did not fully work in the high market volatility seen since the beginning of 2022 mostly due to falling prices of debt securities caused by interest rate increases. The article also contributes to the interpretation of Sharpe and Israelsen ratios in case of similar negative rates of return and different volatility measured, because the Israelsen ratio may not be the best to compare such funds as it prioritizes the funds with lower risk and does not consider relation of risk to return

„Uparte trwanie baroku” w recepcji wierszy Stanisława Barańczaka

The article focuses on the functioning of the term ‘baroque’ in the reception of Stanisław Barańczak’s poems. The author takes into account the context of fashion for returning to the legacy of the baroque which became visible after 1956 in both poetry itself and in the discourse of both literary criticism and literary studies

Air Carrier Pilot Training, Supply & Recruitment Challenges

The route to airline recovery following the global COVID-19 pandemic is flush with opportunity for airlines, unions, and regulators to work together within current regulatory structures to recruit the next generation of aviation professionals, while continuing to ensure they are properly trained, qualified and mentored for safe flight operations. As an industry we have raised interest in pursuing aviation, but more still should be done. The pace of the recovery from the pandemic induced reductions in air travel is testing United States pilot training and recruitment systems. The reductions in air travel at the beginning of the pandemic led to extended leaves, early retirements, as well as seat and aircraft transitions of existing pilots and instructors. In many cases air carriers are now struggling to keep up with the extensive requalification training of them fast enough to accommodate the precipitous increase in passenger air travel. In addition, the need to hire new pilots and instructors is exacerbating the air carrier training department capacity challenges. In some cases, these heavy loads on air carrier training departments are leading to long delays during training, and even retraining due to the excessive delays, adding to the training capacity challenges. This presentation will focus on solutions to safely meet that need with a diverse supply of qualified pilots. This presentation will provide the audience insight into the unique perspectives from human factors, training, and pilot supply experts from the world\u27s largest pilot union on the current state of pilot training, supply and recruitment

New features of modulational instability of partially coherent light; importance of the incoherence spectrum

It is shown that the properties of the modulational instability of partially coherent waves propagating in a nonlinear Kerr medium depend crucially on the profile of the incoherent field spectrum. Under certain conditions, the incoherence may even enhance, rather than suppress, the instability. In particular, it is found that the range of modulationally unstable wave numbers does not necessarily decrease monotonously with increasing degree of incoherence and that the modulational instability may still exist even when long wavelength perturbations are stable.Comment: 4 pages, 2 figures, submitted to Phys. Rev. Let