Instalment options: a closed-form solution and the limiting case

In Foreign Exchange Markets Compound options (options on options) are traded frequently. Instalment options generalize the concept of Compound options as they allow the holder to prolong a Vanilla Call or Put option by paying instalments of a discrete payment plan. We derive a closed-form solution to the value of such an option in the Black-Scholes model and prove that the limiting case of an Instalment option with a continuous payment plan is equivalent to a portfolio consisting of a European Vanilla option and an American Put on this Vanilla option with a time-dependent strike. --exotic options

Business Role-Object Specification: A Language for Behavior-aware Structural Modeling of Business Objects

Representing and reusing the business objects of a domain model for various use cases can be difficult. Especially, if the domain model is acting as a template or a guideline, it is necessary to map the enterprise’s individual structure and processes on the shared domain model. Structural modeling languages often do not meet this requirement of reusing structures and complying to established processes. We propose a modeling language called BROS (Business Role-Object Specification) for describing the business objects’ structure and behavior for structural models, based on a given domain model and process models. It utilizes roles for a use case related specification of business objects as well as events as interfaces for the business processes affecting these roles. Thus, we are able to represent and adapt the business object in different contexts with individual requirements, without changing the underlying domain model. We demonstrate our approach by modeling a simple case

Механический метод очистки сточных вод

В статье рассматриваются основные методы очистки сточных вод. Описан механический метод очистки и представлены его особенности. Приведен процесс очистки вод данным методом. The article deals with the basic methods of wastewater treatment. Described mechanical method of cleaning and presents its features. An process water treatment by this method

Plastic ingestion by juvenile polar cod (Boreogadus saida) in the Arctic Ocean

One of the recently recognised stressors in Arctic ecosystems concerns plastic litter. In this study, juvenile polar cod (Boreogadus saida) were investigated for the presence of plastics in their stomachs. Polar cod is considered a key species in the Arctic ecosystem. The fish were collected both directly from underneath the sea ice in the Eurasian Basin and in open waters around Svalbard. We analysed the stomachs of 72 individuals under a stereo microscope. Two stomachs contained non-fibrous microplastic particles. According to µFTIR analysis, the particles consisted of epoxy resin and a mix of Kaolin with polymethylmethacrylate (PMMA). Fibrous objects were excluded from this analysis to avoid bias due to contamination with airborne micro-fibres. A systematic investigation of the risk for secondary micro-fibre contamination during analytical procedures showed that precautionary measures in all procedural steps are critical. Based on the two non-fibrous objects found in polar cod stomachs, our results show that ingestion of microplastic particles by this ecologically important fish species is possible. With increasing human activity, plastic ingestion may act as an increasing stressor on polar cod in combination with ocean warming and sea-ice decline in peripheral regions of the Arctic Ocean. To fully assess the significance of this stressor and its spatial and temporal variability, future studies must apply a rigorous approach to avoid secondary pollution

Vocational Education and Training and Transitions into the Labor Market

Stage 6 of the German National Educational Panel Study (NEPS) 6 is devoted to the transition of young people from school to work. Stage 6 focuses in particular on the transition from school to vocational education and training and then to work (for tertiary education, see Chap. 16). In all Western societies, vocational education and training (VET) systems face a number of challenges, including the need to adapt to increasing skill requirements across the economy and to handle the danger of producing an "underclass" of low-skilled youth. This chapter presents the life-course approach for investigating school-leavers' pathways from school into the labor market within NEPS. Several factors shape young people’s school-to-work transitions: their motivation and competence endowment, their decisions to apply for specific educational programs, the constraints they face regarding the opportunities for VET programs and the gatekeepers’ recruitment behavior, the information and support youths may or may not receive from social networks, and the learning environments they encounter in firms and schools. We outline the basic theories that guide our research concerning these influences and discuss how we take them into account within NEPS Stage 6. Thus, we provide an overview of the study’s research potential in the area of VET. For now, it is mainly the Scientific Use Files of Starting Cohort 4 (SC4) that provide ample opportunities for innovative interdisciplinary analyses - including analyses of students from special education schools. As the starting cohorts age, Starting Cohort 3 (SC3) has now also entered NEPS Stage 6 and its data on VET transitions will soon be available as well

Less Is More - Estimation of the Number of Strides Required to Assess Gait Variability in Spatially Confined Settings

Background: Gait variability is an established marker of gait function that can be assessed using sensor-based approaches. In clinical settings, spatial constraints and patient condition impede the execution of longer distance walks for the recording of gait parameters. Turning paradigms are often used to overcome these constraints and commercial gait analysis systems algorithmically exclude turns for gait parameters calculations. We investigated the effect of turns in sensor-based assessment of gait variability. Methods: Continuous recordings from 31 patients with movement disorders (ataxia, essential tremor and Parkinson's disease) and 162 healthy elderly (HE) performing level walks including 180° turns were obtained using an inertial sensor system. Accuracy of the manufacturer's algorithm of turn-detection was verified by plotting stride time series. Strides before and after turn events were extracted and compared to respective average of all strides. Coefficient of variation (CoV) of stride length and stride time was calculated for entire set of strides, segments between turns and as cumulative values. Their variance and congruency was used to estimate the number of strides required to reliably assess the magnitude of stride variability. Results: Non-detection of turns in 5.8% of HE lead to falsely increased CoV for these individuals. Even after exclusion of these, strides before/after turns tended to be spatially shorter and temporally longer in all groups, contributing to an increase of CoV at group level and widening of confidence margins with increasing numbers of strides. This could be attenuated by a more generous turn excision as an alternative approach. Correlation analyses revealed excellent consistency for CoVs after at most 20 strides in all groups. Respective stride counts were even lower in patients using a more generous turn excision. Conclusion: Including turns to increase continuous walking distance in spatially confined settings does not necessarily improve the validity and reliability of gait variability measures. Specifically with gait pathology, perturbations of stride characteristics before/after algorithmically excised turns were observed that may increase gait variability with this paradigm. We conclude that shorter distance walks of around 15 strides suffice for reliable and valid recordings of gait variability in the groups studied here

Recommended best practices for plastic and litter ingestion studies in marine birds: Collection, processing, and reporting

doi: 10.1139/facets-2018-0043Marine plastic pollution is an environmental contaminant of significant concern. There is a lack of consistency in sample collection and processing that continues to impede meta-analyses and largescale comparisons across time and space. This is true for most taxa, including seabirds, which are the most studied megafauna group with regards to plastic ingestion research. Consequently, it is difficult to evaluate the impacts and extent of plastic contamination in seabirds fully and accurately, and to make inferences about species for which we have little or no data. We provide a synthesized set of recommendations specific for seabirds and plastic ingestion studies that include best practices in relation to sample collection, processing, and reporting, as well as highlighting some “cross-cutting” methods. We include guidance for how carcasses, regurgitations, and pellets should be handled and treated to prevent cross-contamination, and a discussion of what size class of microplastics can be assessed in each sample type. Although we focus on marine bird samples, we also include standardized techniques to remove sediment and biological material that are generalizable to other taxa. Lastly, metrics and data presentation of ingested plastics are briefly reviewed in the context of seabird studies.Copyright: © 2019 Provencher et al. This work is licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author(s) and source are credited. The attached file is the published pdf