Transnational Lived Citizenship - The Case of the Eritrean Diaspora

This special focus section analyses state-diaspora relationships with a focus on the case of Eritrea, a paradigmatic example, as we show in this introduction, to elaborate on the following key questions: What determines loyalty between diaspora and the state? How can we understand the dynamics of co-optation, loyalty, and resistance that characterise many diaspora-state relationships? What is the role of historical events and memory in building alliances as well as divides among different generations and different groups in the diaspora? How do diaspora citizens interpret and enact their citizenship in everyday practices of engagement? By engaging with both citizenship and diaspora studies, this introduction shows the significance of analysing these questions through the lens of "transnational lived citizenship." This concept enables a look at the intersections between formal aspects of citizenship as well as the emotional and practical aspects related to feelings of belonging, transnational attitudes, and circulation of material cultures

Electron-beam broadening in electron microscopy by solving the electron transport equation

Scanning transmission electron microscopy (STEM) and scanning electron microscopy (SEM) are prominent techniques for the structural characterization of materials. STEM in particular provides high spatial resolution down to the sub-ångström range. The spatial resolution in STEM and SEM is ultimately limited by the electron-beam diameter provided by the microscope\u27s electron optical system. However, the resolution is frequently degraded by the interaction between electron and matter leading to beam broadening, which depends on the thickness of the analyzed sample. Numerous models are available to calculate beam broadening. However, most of them neglect the energy loss of the electrons and large-angle scattering. These restrictions severely limit the applicability of the approaches for large sample thicknesses in STEM and SEM. In this work, we address beam broadening in a more general way. We numerically solve the electron transport equation without any simplifications, and take into account energy loss along the electron path. For this purpose, we developed the software package CeTE (Computation of electron Transport Equation). We determine beam broadening, energy deposition, and the interaction volume of the scattered electrons in homogeneous matter. The calculated spatial and angular distributions of electrons are not limited to forward scattering and small sample thicknesses. We focus on low electron energies of 30 keV and below, where beam broadening is particularly pronounced. These electron energies are typical for SEM and STEM in scanning electron microscopes

A Pathway for the Practical Adoption of Federated Machine Learning Projects

Big data forms the fundamental basis for the success of Machine Learning. Yet, a large amount of the world’s digitized data is locked up in data silos, leaving its potential untapped. Federated Machine Learning is a novel Machine Learning paradigm with the potential to overcome data silos by enabling the decentralized training of Machine Learning models through a model-to-data approach. Despite its potential advantages, most Federated Machine Learning projects fail to actualize due to their decentralized structure and incomprehensive interrelations. Current literature lacks clear guidelines on which steps need to be performed to successfully implement Federated Machine Learning projects. This study aims to close this research gap. Through a design science research approach, we provide three distinct activity models which outline required tasks in the development of Federated Machine Learning systems. Thereby, we aim to reduce complexity and ease the implementation process by guiding practitioners through the project life cycle

Quantification of the thickness of TEM samples by low-energy scanning transmission electron microscopy

Precise knowledge of the local sample thickness is often required for quantitative scanning (transmission) electron microscopy (STEM). The local sample thickness can be determined by the comparison of measured intensities from high-angle annular dark-field (HAADF)-STEM at low energies (<30 keV) with Monte-Carlo simulations. However, a suitable choice of the scattering cross-section (CS) used in the simulations is necessary to gain reliable thickness results. In this work, simulations using different CS, including the Screened Rutherford CS and different Mott CSs, were performed. The results were then compared with measurements on samples with known thickness and composition, for which an SEM equipped with a STEM detector was used. In most cases, the Screened Rutherford CS describes the experiment better than other CSs

Main challenges and key features of indicator-based agroecological assessment frameworks in the context of international cooperation

Agroecology increasingly gains importance in the discussion about sustainable food systems. To facilitate the transition from conventional farming to agroecological farming, adequate methods and concepts to measure and assess impact and productivity of agroecological farming systems (AFSs) are needed, which consider their multifunctionality and other specific characteristics, here called agroecological sustainability assessment frameworks and tools (ASAFTs). In the past years, many agricultural sustainability assessment tools and frameworks were developed but their suitability and applicability to AFSs was not investigated. To close this knowledge gap, we aimed at identifying, reviewing, and discussing published ASAFTs in the context of international cooperation, providing an overview of the current challenges, needs, and requirements in assessing AFSs at the farm level with the means of indicators. Desktop and scientific database research was conducted to identify and discuss published indicator-based ASAFTs at the farm level. The analysis was based on the following four framework elements that the authors considered to be essential for ASAFTs: (1) the adaptability to local conditions all over the world, (2) the involvement of farmers in the development process, (3) the consideration of the multiple functions of an agroecosystem in the definition and measurement of its productivity, and (4) the accounting for interactions between multiple agroecosystem functions and their measurement. Only a few analyzed assessment frameworks at least partly consider these essential elements and were designed specifically for AFSs. However, our study also showed that these frameworks were (1) restricted in their geographical application scope, (2) quite heterogeneous and barely comparable, and (3) based on productivity indicators that do not fully capture the multiple functions of AFSs. Therefore, we identified the need for the development of appropriate agroecological productivity indicators and common standard or reference frameworks for assessing AFSs, which will be crucial for upscaling agroecology

Beam broadening measured in transmission mode at low electron energies in a scanning electron microscope

The broadening of the electron beam in the sample has to be considered when performing scanning transmission electron microscopy (STEM) at low primary electron energies. This work presents direct measurements of the beam broadening in a range of materials. The experimental results are compared with the theoretical model by Gauvin and Rudinsky that uses the concept of anomalous diffusion to obtain an analytical equation for the beam broadening

Comorbidities Associated with Large Abdominal Aortic Aneurysms

BACKGROUND: Abdominal aortic aneurysm has become increasingly important owing to demographic changes. Some other diseases, for example, cholecystolithiasis, chronic obstructive pulmonary disease, and hernias, seem to co-occur with abdominal aortic aneurysm. The aim of this retrospective analysis was to identify new comorbidities associated with abdominal aortic aneurysm. METHODS: We compared 100 patients with abdominal aortic aneurysms and 100 control patients. Their preoperative computed tomographic scans were examined by two investigators independently, for the presence of hernias, diverticulosis, and cholecystolithiasis. Medical records were also reviewed. Statistical analysis was performed using univariate analysis and multiple logistic regression analysis. RESULTS: The aneurysm group had a higher frequency of diverticulosis (p = 0.008). There was no significant difference in the occurrence of hernia (p = 0.073) or cholecystolithiasis (p = 1.00). Aneurysm patients had a significantly higher American Society of Anesthesiology score (2.84 vs. 2.63; p = 0.015) and were more likely to have coronary artery disease (p < 0.001), congestive heart failure (p < 0.001), or chronic obstructive pulmonary disease (p < 0.001). Aneurysm patients were more likely to be former (p = 0.034) or current (p = 0.006) smokers and had a significantly higher number of pack years (p < 0.001). Aneurysm patients also had a significantly poorer lung function. In multivariate analysis, the following factors were associated with aneurysms: chronic obstructive pulmonary disease (odds ratio, OR = 12.24; p = 0.002), current smoking (OR = 4.14; p = 0.002), and coronary artery disease (OR = 2.60; p = 0.020). CONCLUSIONS: Our comprehensive analysis identified several comorbidities associated with abdominal aortic aneurysms. These results could help to recognize aneurysms earlier by targeting individuals with these comorbidities for screening

Fast Determination of the Thickness of Electron-Transparent Specimens using Quantitative STEM-in-SEM and Monte-Carlo Simulations

Accurate values for the thickness of electron-transparent specimens in electron microscopy are of general interest, e.g. as a parameter for quantitative simulations and calculations in the field of transmission electron microscopy (TEM). Several thickness-determination techniques exist, e.g. based on plasmon losses in electron energy loss spectra, convergent-beam electron diffraction, or exploitation of thickness contours in images acquired under two-beam diffraction conditions. However, the accuracy, precision, and time consumption differs significantly and often yields thickness values only for a small sample region. We will show in this work that scanning transmission electron microscopy (STEM) in a scanning electron microscope (STEM-in-SEM) is well suited for thickness determination with rather satisfying accuracy (error within a few percent). This technique has been further elaborated by us after previous initial work. We will give an in-depth instruction and discussion of the technique so that users can avoid pitfalls