Veritaa: A distributed public key infrastructure with signature store

Today, the integrity and authenticity of digital documents and data are often hard to verify. Existing public key infrastructures (PKIs) are capable of certifying digital identities but do not provide solutions to store signatures immutably, and the process of certification is often not transparent. We propose Veritaa, a distributed public key infrastructure with an integrated signature store (DPKISS). The central part of Veritaa is the Graph of Trust that manages identity claims and singed declarations between identity claims and document identifiers. An application-specific distributed ledger is used to store the transactions that form the Graph of Trust immutably. For the distributed certification of identity claims, a reputation system based on signed trust declarations and domain vetting is used. In this work, we have designed and implemented the proposed architecture of Veritaa, created a testbed, and performed several experiments. The experiments show the benefits and the high performance of Veritaa

Effective behavior change techniques in digital health interventions targeting non-communicable diseases: an umbrella review

Background: Despite an abundance of digital health interventions (DHIs) targeting the prevention and management of common non-communicable diseases (NCDs), it is unclear what specific components make an intervention effective in changing human behavior.Purpose: The aim of this umbrella review was to identify the most effective behavior change techniques (BCTs) in DHIs that address the most common NCDs. Methods: Five electronic databases were searched for articles published in English between 1st January 2007 and 24th January 2021. Studies were included if they were systematic reviews or meta-analyses of e- or mHealth interventions targeting the modification of one or more NCD-related risk factors in adults. Study quality was assessed using AMSTAR 2. Sixty-one articles, spanning 10 health domains and comprising over half a million individual participants, were included in the review. Results: DHIs are favorably associated with improved health outcomes for patients with cardiovascular disease, cancer, type 2 diabetes, and asthma, and health-related behaviors including physical activity, sedentary behavior, diet, weight management, medication adherence, and abstinence from substance use. There was strong evidence to suggest education, communication with a professional, tailored reminders, goals and planning, feedback and monitoring, and personalization components increase the effectiveness of DHIs targeting NCDs and lifestyle behaviors. Conclusions: Common BCTs across health domains, such as ‘goals and planning’, increase DHI effectiveness and should be prioritized for inclusion within future interventions. These findings are critical for the future development and upscaling of DHIs and should inform best practice guidelines

Effect of boron doping on grain boundary cohesion in technically pure molybdenum investigated via meso-scale three-point-bending tests

Molybdenum has numerous advantageous functional and high-temperature properties. However, plastic deformation as well as structural applications are limited due to a propensity for brittle, intercrystalline failure, especially at low temperatures. It is well known that oxygen segregations have a detrimental effect, whereas it is assessed that carbon and/or boron have a beneficial effect on grain boundary cohesion. An advanced approach for the improvement of these interfaces is segregation engineering, e.g. the addition of cohesion enhancing elements segregating to the grain boundaries. To investigate early stages of crack formation, three-point bending tests on recrystallized commercially pure and boron micro-doped molybdenum were conducted between −28 \ub0C and room temperature. The tensile-loaded top surface of the specimens was examined post-mortem close to the final fracture area via scanning electron microscopy. The occurring separations of grains are investigated for distinct features and the chemical composition of the interface is complementary measured by atom probe tomography

Exploring the mechanical character of molybdenum grain boundaries via nanoindentation and three-point-bending

The interactions of interfaces with dislocations have been extensively studied in the past. Still, there is a lack of high throughput methods, which can potentially be used for systematic studies to cover a wide range of grain boundary types. Nanoindentation offers the opportunity to combine a high spatial resolution with high effectiveness, thus enabling to obtain comprehensive mechanical data in the vicinity of grain boundaries. The present study on coarse-grained molybdenum will show results of mechanical property mapping near grain boundaries. Here, for the first time also the indenter tip rotation angle with respect to the loading axis as well as the grain orientation are considered. Results will show that neglecting these parameters can bias interpretations of the interface/dislocation interactions, as the localized deformation paths around the indentation are thereby significantly changed. Systematic experiments on commercially pure, recrystallized molybdenum have been performed to investigate the dependence of the hardness increase near grain boundaries with respect to the boundary misorientation angle. As a complementary method, three-point-bending is applied on mm-sized specimens until individual grain boundaries delaminate, which in turn will be identified and cross-checked with findings of the nanoindentation tests. Doping molybdenum with elements like carbon and/or boron is known to suppress intercrystalline failure. For this reason, the presented grain boundary characterization methods will be applied to extract mechanical changes caused by these doping elements

Evolution of nano-pores during annealing of technically pure molybdenum sheet produced from different sintered formats

Molybdenum is a refractory metal with no phase transformation in the solid state and a high melting point. It is therefore an excellent structural material for various high temperature applications. Especially in this field of operation, significant creep resistance is essential. To achieve this, a microstructure with grains in the range of millimeters is desired. However, as demonstrated in the present study, the onset temperature for secondary recrystallization, which would lead to a beneficial grain size, is among other things dependent on the initial dimensions of the sintered part. One possible reason for the different microstructural evolutions is the influence of residual pores in sub-micrometer size. Sheets were thus fabricated via three different production routes employing the same initial Mo powder to exclude chemical variation as an influencing factor. The samples were investigated by in-situ small-angle X-ray scattering at a synchrotron radiation source with two different heating rates. Additionally, selected annealed samples were studied ex-situ with high energy X-rays. The apparent volume fraction of pores is compared to a volatilization model for the vaporization of typical accompanying elements and the induced thermal expansion

Sex hormones and sperm parameters after adjuvant oxaliplatin-based treatment for colorectal cancer

Publisher Copyright: © 2022 The Author(s)Background: The incidence of colorectal cancer (CRC) in individuals of fertile age is increasing. Oxaliplatin is a cornerstone treatment in the adjuvant setting for stage III and high-risk stage II CRC. Limited data exist on possible side effects of oxaliplatin on fertility and gonadal function. More data is needed to guide possible fertility preservation procedures and aid evidence-based fertility counselling. Patients and methods: The aim of this study (EudraCT2006-002832-10) was to prospectively investigate sex hormones and sperm parameters after oxaliplatin-based adjuvant chemotherapy to clarify the risk of infertility and hypogonadism. Twenty males aged ≤55 years and 16 females aged ≤40 years were recruited from five hospitals in the Nordic countries. All had undergone radical surgery due to CRC and were given adjuvant oxaliplatin in combination with 5-fluorouracil. Measurement of luteinizing hormone (LH), follicle-stimulating hormone (FSH), testosterone, sex hormone binding globulin (SHBG) and semen analysis were done in males, while LH, FSH and oestradiol were measured in females. Measurements were done prior to chemotherapy, after completion of adjuvant treatment and at follow-up 1 and up to 5 years after end of treatment. Results: FSH and testosterone levels increased in males after chemotherapy treatment but were restored at follow-up. No patients developed hypogonadism. There was a trend towards a decrease in sperm concentration during treatment (p = 0.063). When comparing sperm concentration and rapid progressive motility of sperms prior to chemotherapy and at follow-up, there were no differences, and no patients became permanently azoospermic by treatment. No distinct altering of gonadal function could be observed in females. Conclusions: Oxaliplatin in combination with 5-fluorouracil seems to induce transient decrease in sperm concentration with recovery and a minor transient increase in FSH in males. No distinct altering of gonadal function was observed in females. The risk of infertility and hypogonadism in males and females after adjuvant oxaliplatin-based chemotherapy seems low.Peer reviewe

Effective Behavior Change Techniques in Digital Health Interventions for the Prevention or Management of Noncommunicable Diseases: An Umbrella Review

Background Despite an abundance of digital health interventions (DHIs) targeting the prevention and management of noncommunicable diseases (NCDs), it is unclear what specific components make a DHI effective. Purpose This narrative umbrella review aimed to identify the most effective behavior change techniques (BCTs) in DHIs that address the prevention or management of NCDs. Methods Five electronic databases were searched for articles published in English between January 2007 and December 2022. Studies were included if they were systematic reviews or meta-analyses of DHIs targeting the modification of one or more NCD-related risk factors in adults. BCTs were coded using the Behavior Change Technique Taxonomy v1. Study quality was assessed using AMSTAR 2. Results Eighty-five articles, spanning 12 health domains and comprising over 865,000 individual participants, were included in the review. We found evidence that DHIs are effective in improving health outcomes for patients with cardiovascular disease, cancer, type 2 diabetes, and asthma, and health-related behaviors including physical activity, sedentary behavior, diet, weight management, medication adherence, and abstinence from substance use. There was strong evidence to suggest that credible source, social support, prompts and cues, graded tasks, goals and planning, feedback and monitoring, human coaching and personalization components increase the effectiveness of DHIs targeting the prevention and management of NCDs. Conclusions This review identifies the most common and effective BCTs used in DHIs, which warrant prioritization for integration into future interventions. These findings are critical for the future development and upscaling of DHIs and should inform best practice guidelines

The bacterium Pseudomonas protegens antagonizes the microalga Chlamydomonas reinhardtii using a blend of toxins

The unicellular alga Chlamydomonas reinhardtii and the bacterium Pseudomonas protegens serve as a model to study the interactions between photosynthetic and heterotrophic microorganisms. P . protegens secretes the cyclic lipopeptide orfamide A that interferes with cytosolic Ca 2+ homeostasis in C . reinhardtii resulting in deflagellation of the algal cells. Here, we studied the roles of additional secondary metabolites secreted by P . protegens using individual compounds and co‐cultivation of algae with bacterial mutants. Rhizoxin S2, pyrrolnitrin, pyoluteorin, 2,4‐diacetylphloroglucinol (DAPG) and orfamide A all induce changes in cell morphology and inhibit the growth of C . reinhardtii . Rhizoxin S2 exerts the strongest growth inhibition, and its action depends on the spatial structure of the environment (agar versus liquid culture). Algal motility is unaffected by rhizoxin S2 and is most potently inhibited by orfamide A (IC 50 = 4.1 μM). Pyrrolnitrin and pyoluteorin both interfere with algal cytosolic Ca 2+ homeostasis and motility whereas high concentrations of DAPG immobilize C . reinhardtii without deflagellation or disturbance of Ca 2+ homeostasis. Co‐cultivation with a regulatory mutant of bacterial secondary metabolism (Δ gacA ) promotes algal growth under spatially structured conditions. Our results reveal how a single soil bacterium uses an arsenal of secreted antialgal compounds with complementary and partially overlapping activities

Production of Lambda and Sigma^0 hyperons in proton-proton collisions

This paper reports results on simultaneous measurements of the reaction channels pp -> pK+\Lambda and pp -> pK+\Sigma^0 at excess energies of 204, 239, and 284 MeV (\Lambda) and 127, 162, and 207 MeV (\Sigma^0). Total and differential cross sections are given for both reactions. It is concluded from the measured total cross sections that the high energy limit of the cross section ratio is almost reached at an excess energy of only about 200 MeV. From the differential distributions observed in the overall CMS as well as in the Jackson and helicity frames, a significant contribution of interfering nucleon resonances to the \Lambda production mechanism is concluded while resonant \Sigma^0-production seems to be of lesser importance and takes place only through specific partial waves of the entrance channel. The data also indicate that kaon exchange plays a minor role in the case of \Lambda- but an important role for \Sigma^0-production. Thus the peculiar energy dependence of the \Lambda-to-\Sigma^0 cross section ratio appears in a new light as its explanation requires more than mere differences between the p\Lambda and the p\Sigma^0 final state interaction. The data provide a benchmark for theoretical models already available or yet to come.Comment: 18 pages, 10 figures; accepted by The European Physical Journal A (EPJ A