Optimization methods and their use in low-energy electron-diffraction calculations

The speed of automatic optimization procedures used in surface structure determination by low-energy electron diffraction can be greatly enhanced by the use of linear approximations in the calculation of scattering amplitudes. It is shown how linear approximations can be used in the calculation of derivatives of intensities which are required in the least-squares optimization method. The derivatives with respect to structural and nonstructural parameters are calculated applying a combination of analytic and numerical methods in connection with approximations of the sum over lattice points in the angular momentum representation. Special cases for different structural and nonstructural parameters and simplifications for special geometries are discussed. The computational effort becomes nearly independent of the number of free parameters and enables the analysis of complex surface structures

Stage-specific incidence trends of renal cancers in the East of England, 1999-2016

Objectives: To determine stage-specific time-trends in renal cancer incidence. Methods: We used population-based East Anglia data 1999−2016 (population ∼2 million) on 5,456 primary renal cancer diagnoses, estimating stage-specific annual incidence using Poisson regression, allowing for changing time-trends, and adjusting for sex, age, and socioeconomic deprivation. Results: Renal cancer incidence increased from 9.8–16.4 cases per 100,000 during 1999−2016. Incidence of Stage I, II, and III cases increased over time, most steeply for Stage I, with annual Incidence Rate Ratio [IRR] for Stage I of 1.09 (95 % CI 1.07–1.12) during 1999−2010; and 1.03 (1.00–1.05) during 2011−2016. In contrast, the annual incidence of Stage IV renal cancer decreased during most years, IRR of 0.99 (0.98–1.00) during 2003−2016. Conclusion: The findings are consistent with both earlier detection of symptomatic renal cancer and increasing identification of asymptomatic lesions. However, the decreasing incidence of late-stage disease suggests genuine shifts towards earlier diagnosis

Tube choledochoureterostomy: A simple method for bile diversion

A technique of bile diversion by tube choledochoureterostomy has been devised for the purpose of studying the role of bile in the intestinal absorption of drugs. This method was used in six dogs. No technical difficulties or major complications developed, as are inevitable with alternative methods, including external fistula. © 1990 Informa UK Ltd All rights reserved: reproduction in whole or part not permitted

Emerging strategies for regeneration of historic urban sites:a systematic literature review

The importance and effectiveness of adaptive reuse as an alternative to the demolition of cultural heritage is well-studied. However, increasing demand in cities to redevelop larger scale urban historic sites requires new strategies to benefit from their inherent values. This paper focuses on strategies of regeneration for historic urban sites. The paper presents a systematic literature review of 45 papers, with case studies geographically concentrated in Europe and Asia, and a focus on residential, commercial, and industrial areas. From the case studies, 46 different regeneration strategies have been deduced. The various strategies are, via content analysis, dissected into a select number of drivers to find commonalities. These key drivers are user participation, top-down, genius loci, sustainability, and conversion. Based on the reflections of the reviewed authors, a performance evaluation assesses the outcomes of these strategies. Further data analysis is conducted at the level of individual drivers as well as their combinations to deduce the most positive-evaluated strategies. Findings show that genius loci contributes to the most positive-evaluated strategies, while top-down driven strategies contribute to the most negative-evaluated strategies. Furthermore, strategies are assessed positively when three or more drivers are considered regardless of their combination. This paper acts as a starting point for further research into the formation of regeneration strategies and into the specific drivers and their combinations or underlying relations. Moreover, it can be of contribution to the practice, to support decision makers and urban planners in developing the appropriate regeneration strategy for historic urban sites

Squamous Cell Carcinoma of the Skin and Coal Tar Creosote Exposure in a Railroad Worker

A 50-year-old male railroad worker presented to his primary care physician with an erythematous, tender skin lesion on the right knee; a biopsy of this lesion revealed squamous cell carcinoma in situ. The site of the lesion was sun-protected but had been associated with 30 years of creosote-soaked clothing. In this article, we review dermal and other malignancies associated with creosote, along with creosote occupational exposures and exposure limits. This is a unique case, given the lack of other, potentially confounding, polyaromatic hydrocarbons and the sun-protected location of the lesion

Personalisation and recommender systems in digital libraries

Widespread use of the Internet has resulted in digital libraries that are increasingly used by diverse communities of users for diverse purposes and in which sharing and collaboration have become important social elements. As such libraries become commonplace, as their contents and services become more varied, and as their patrons become more experienced with computer technology, users will expect more sophisticated services from these libraries. A simple search function, normally an integral part of any digital library, increasingly leads to user frustration as user needs become more complex and as the volume of managed information increases. Proactive digital libraries, where the library evolves from being passive and untailored, are seen as offering great potential for addressing and overcoming these issues and include techniques such as personalisation and recommender systems. In this paper, following on from the DELOS/NSF Working Group on Personalisation and Recommender Systems for Digital Libraries, which met and reported during 2003, we present some background material on the scope of personalisation and recommender systems in digital libraries. We then outline the working group’s vision for the evolution of digital libraries and the role that personalisation and recommender systems will play, and we present a series of research challenges and specific recommendations and research priorities for the field