An Efficient Computation of Coherent Synchrotron Radiation in a Rectangular Chamber, Applied to Resistive Wall Heating

We study coherent synchrotron radiation (CSR) in a perfectly conducting vacuum chamber of rectangular cross section, in a formalism allowing an arbitrary sequence of bends and straight sections. We apply the paraxial method in the frequency domain, with a Fourier development in the vertical coordinate but with no other mode expansions. A line charge source is handled numerically by a new method that rids the equations of singularities through a change of dependent variable. The resulting algorithm is fast compared to earlier methods, works for short bunches with complicated structure, and yields all six field components at any space-time point. As an example we compute the tangential magnetic field at the walls. From that one can make a perturbative treatment of the Poynting flux to estimate the energy deposited in resistive walls. The calculation was motivated by a design issue for LCLS-II, the question of how much wall heating from CSR occurs in the last bend of a bunch compressor and the following straight section. Working with a realistic longitudinal bunch form of r.m.s. length $10.4~\mu$m and a charge of 100 pC we conclude that the radiated power is quite small (28 W at a 1 MHz repetition rate), and all radiated energy is absorbed in the walls within 7 m along the straight section.Comment: 47 pages, 24 figure

Preliminary results of investigations into the use of artificial neural networks for discriminating gas chromatograph mass spectra of remote samples

Neural networks trained using mass spectra data from the National Institute of Standards and Technology (NIST) are studied. The investigations also included sample data from the gas chromatograph mass spectrometer (GCMS) instrument aboard the Viking Lander, obtained from the National Space Science Data Center. The work performed to data and the preliminary results from the training and testing of neural networks are described. These preliminary results are presented for the purpose of determining the viability of applying artificial neural networks in discriminating mass spectra samples from remote instrumentation such as the Mars Rover Sample Return Mission and the Cassini Probe

The U.S. system for measuring cross-border investment in securities: a primer with a discussion of recent developments

The tremendous growth in cross-border securities investment in recent years has called attention to the systems used by the United States and other countries to measure international securities flows and holdings. Ideally, the data gathered by the United States could tell us the extent to which foreign investors hold U.S. securities, the types of securities held, and the countries in which the securities are held, for example, and could identify trends in investment. This article looks at how well the data shed light on these topics. Special attention is given to the system's design and the implications of the design for data analysis. Also discussed are anticipated changes to the system and international efforts to improve data collection systems worldwide.International finance ; Securities

Processed Chili Peppers for Export Markets: A Capital Budgeting Study on the AgroFood Company

The AgroFood Company, which currently exports fresh chili peppers to European clients, desires to expand the product mix offered. The company, as it expands its production of fresh peppers for export, has an increasing supply of grade 2 peppers that are unmarketable in Egypt. However, an attractive market for processed frozen chili peppers exists in Europe. To expand their client base, capitalize on a value added product, and minimize product waste, the AgroFood Company desires to develop processing practices for chili peppers produced in Egypt. The AgroFood Company would like to identify its options in the processed pepper market. An analysis of the company, competition, consumer, market channel, and conditions, provides insight into possible solutions to the challenges faced by the farm management. Designed for undergraduate classroom use, this case will provide students with an opportunity to evaluate the merits of business expansion into a high capacity, automated mechanical processing facility for grade 2 vegetables.Decision case, horticulture, agriculture economics, chili pepper production, protected vegetable production, Crop Production/Industries, Food Security and Poverty, Production Economics,

Franck-Condon Blockade in a Single-Molecule Transistor

We investigate vibron-assisted electron transport in single-molecule transistors containing an individual Fe4 Single-Molecule Magnet. We observe a strong suppression of the tunneling current at low bias in combination with vibron-assisted excitations. The observed features are explained by a strong electron-vibron coupling in the framework of the Franck-Condon model supported by density-functional theory

Market Developments on Chinese International Air Passenger Markets in Light of COVID-19 Policy Measures

The world’s governments imposed a plethora of restrictions and quarantine rules to prevent the rapid spread of COVID-19. China was chosen for this study as it was the first market to be impacted. The overall aim of this paper was to analyse international air travel to and from China since the start of COVID-19 and to assess the impact of policy initiatives on seat capacity during this time. The key findings are that implementation of the so called Five one policy in March 2020 was associated with an almost immediate reduction in seat capacity on China to the rest of the world, partially suppressing the more typical impact of underlying GDP and air fares on capacity. It was further found that Chinese international gateways, as airports with substantial proportions of international and connecting traffic, remain the most distressed. Long haul international traffic and revenues from European and North American destinations all experienced unprecedented and sharp reductions. Traffic and revenues from other Asian markets was even more sporadic. Alarmingly, the study extracted that revenues from premium classes were deteriorating much faster than economy class, which is of imminent concern for long-haul carriers reliant on premium traffic coming into the pandemic

Urinary Tubular Injury Biomarkers Are Associated With ESRD and Death in the REGARDS Study.

IntroductionUrinary neutrophil gelatinase-associated lipocalin (uNGAL) and urinary kidney injury molecule-1 (uKIM-1) are established markers of subclinical acute kidney injury. In persons with reduced estimated glomerular filtration rate (eGFR) and albuminuria who are at high risk for end-stage renal disease (ESRD) and death, the associations of these urinary markers with incident ESRD or death is an area of active investigation.MethodsAmong 1472 black and white participants from the REasons for Geographic and Racial Differences in Stroke (REGARDS) study with eGFR ≤60 ml/min per 1.73 m2 (Chronic Kidney Disease Epidemiology Collaboration [CKD-EPI] cystatin, 2012) and albumin-to-creatinine ratio (ACR) ≥30 mg/g, we evaluated the associations of baseline uNGAL and uKIM-1 with progression to ESRD and all-cause death. Cox models were sequentially adjusted for urinary creatinine, traditional risk factors, C-reactive protein, ACR, and eGFR.ResultsThere were 257 ESRD events and 819 deaths over a median follow-up of 5.7 and 6.5 years, respectively. In demographic adjusted models, higher levels of uNGAL were associated with increased risk of ESRD and death, but these associations were attenuated in fully adjusted models including baseline eGFR for both ESRD (hazard ratio [HR] = 1.06 per doubling, 95% confidence interval [CI] 0.98-1.14) and death (HR = 1.04, 95% CI = 1.00-1.08). Higher levels of uKIM-1 were associated with increased risk of ESRD and death in demographic-adjusted models, and although attenuated in fully adjusted models, remained statistically significant for both ESRD (HR = 1.24 per doubling, 95% CI = 1.08-1.42) and death (HR = 1.10, 95% CI =1.03-1.19).ConclusionIn this cohort of high-risk patients with baseline eGFR ≤60 ml/min per 1.73 m2 and albuminuria, renal tubular injury is associated with higher mortality and progression to ESRD. Further studies are necessary to investigate the mechanism underlying this increased risk

Creating the ‘ethics industry': Mary Warnock, in vitro fertilization and the history of bioethics in Britain

Recent decades have seen a shift in the management and discussion of biomedicine. Issues once considered by doctors and scientists are now handled by a diverse array of participants, including philosophers, lawyers, theologians and lay representatives. This new approach, known as ‘bioethics', has become the norm in regulatory committees and public debate. In this article, I argue that bioethics emerged as a valued enterprise in Britain during the 1980s because it fulfilled, and linked, the concerns of several groups. My analysis centres on the moral philosopher Mary Warnock, who chaired a government inquiry into human fertilization and embryology between 1982 and 1984, and became a strong advocate of bioethics. I detail how Warnock's promotion of bioethics tallied with the Conservative government's desire for increased surveillance of hitherto autonomous professions – while fulfilling her own belief that philosophers should engage in public affairs. And I also show that Warnock simultaneously promoted bioethics to doctors and scientists as an essential safeguard against declining political and public trust. This stance, I argue, framed bioethics as a vital intermediary between politics, the public, and biomedicine, and explains the growth and endurance of what the Guardian identified as an ethics industry