Naïve learning in social networks with random communication

We study social learning in a social network setting where agents receive independent noisy signals about the truth. Agents naïvely update beliefs by repeatedly taking weighted averages of neighbors’ opinions. The weights are fixed in the sense of representing average frequency and intensity of social interaction. However, the way people communicate is random such that agents do not update their belief in exactly the same way at every point in time. Our findings, based on Theorem 1, Corollary 1 and simulated examples, suggest the following. Even if the social network does not privilege any agent in terms of influence, a large society almost always fails to converge to the truth. We conclude that wisdom of crowds seems an illusive concept and bares the danger of mistaking consensus for truth

Compensating for low topic interest and long surveys: a field experiment on nonresponse in web surveys

Certain survey characteristics proven to affect response rates, such as a survey’s length and topic, are often under limited control of the researcher. Therefore, survey researchers sometimes seek to compensate for such undesired effects on response rates by employing countermeasures such as material or nonmaterial incentives. The scarce evidence on those factors’ effects in web survey contexts is far from being conclusive. This study is aimed at filling this gap by examining the effects of four factors along with selected interactions presumed to affect response rates in web surveys. Requests to complete a web-based, selfadministered survey were sent to 2,152 owners of personal websites. The 2 X 2 X 2 X 2 fully crossed factorial design encompassed the experimental conditions of (a) high versus low topic salience, (b) short versus long survey, (c) lottery incentive versus no incentive, and (d) no feedback and general feedback (study results) versus personal feedback (individual profile of results). As expected, highly salient and shorter surveys yielded considerably higher unit-response rates. Moreover, partial support was found for interaction hypotheses derived from the leverage-salience theory of survey participation. Offering personalized feedback compensated for the negative effects of low topic salience on response rates. Also, the lottery incentive tended to evoke more responses only if the survey was short (versus long), but this interaction effect was only marginally significant. The results stress the usefulness of a multifactorial approach encompassing interaction effects to understand participation differences in web surveys. (auhtor'S abstract

Addressing directionality: Orientation failure and the systems of innovation heuristic. Towards reflexive governance

[Introduction] Since about 15 years, science, technology and innovation (STI) policies are increasingly geared towards addressing objectives reaching beyond an immediate economic focus on growth and competitiveness. This "normative turn" (Daimer et al. 2012) is expressed in the strategic reorientation of national and supranational STI policies to address the so-called ‘grand challenges’ (Kallerud et al. 2013). Well known examples for this ongoing paradigm shift are the European Union's Europe 2020 strategy, the US Strategy for American Innovation or Germany's Hightech Strategy. What is more, the quest to address ‘grand challenges’ such as health, demographic change, wellbeing and sustainability by the means of research and innovation is complemented by and propelled forward by the emerging discourse on responsible (research and) innovation. In essence, RRI aims at improving the alignment of the impacts of technology and innovation with societal demands and values as far as possible. The concept is inherently characterised by a high degree of normativity in order to provide necessary guidance as to what constitutes desired or ‘responsible’ research and innovation (Randles et al. 2014; Lindner and Kuhlmann 2016). The prominent position of RRI in the European Union's research and innovation programme 'Horizon 2020' and the endorsement of the "Rome Declaration on RRI in Europe" by the European Council in 2014 indicate that RRI is increasingly developing relevance for policy, research funding and scientific communities. [...

Completeness and consistency of primary outcome reporting in COVID-19 publications in the early pandemic phase: a descriptive study

Background The COVID-19 pandemic saw a steep increase in the number of rapidly published scientific studies, especially early in the pandemic. Some have suggested COVID-19 trial reporting is of lower quality than typical reports, but there is limited evidence for this in terms of primary outcome reporting. The objective of this study was to assess the prevalence of completely defined primary outcomes reported in registry entries, preprints, and journal articles, and to assess consistent primary outcome reporting between these sources. Methods This is a descriptive study of a cohort of registered interventional clinical trials for the treatment and prevention of COVID-19, drawn from the DIssemination of REgistered COVID-19 Clinical Trials (DIRECCT) study dataset. The main outcomes are: 1) Prevalence of complete primary outcome reporting; 2) Prevalence of consistent primary outcome reporting between registry entry and preprint as well as registry entry and journal article pairs. Results We analyzed 87 trials with 116 corresponding publications (87 registry entries, 53 preprints and 63 journal articles). All primary outcomes were completely defined in 47/87 (54%) registry entries, 31/53 (58%) preprints and 44/63 (70%) journal articles. All primary outcomes were consistently reported in 13/53 (25%) registry-preprint pairs and 27/63 (43%) registry-journal article pairs. No primary outcome was specified in 13/53 (25%) preprints and 8/63 (13%) journal articles. In this sample, complete primary outcome reporting occurred more frequently in trials with vs. without involvement of pharmaceutical companies (76% vs. 45%), and in RCTs vs. other study designs (68% vs. 49%). The same pattern was observed for consistent primary outcome reporting (with vs. without pharma: 56% vs. 12%, RCT vs. other: 43% vs. 22%). Conclusions In COVID-19 trials in the early phase of the pandemic, all primary outcomes were completely defined in 54%, 58%, and 70% of registry entries, preprints and journal articles, respectively. Only 25% of preprints and 43% of journal articles reported primary outcomes consistent with registry entries

Completeness and consistency of primary outcome reporting in COVID-19 publications in the early pandemic phase : a descriptive study

Background: The COVID-19 pandemic saw a steep increase in the number of rapidly published scientific studies, especially early in the pandemic. Some have suggested COVID-19 trial reporting is of lower quality than typical reports, but there is limited evidence for this in terms of primary outcome reporting. The objective of this study was to assess the prevalence of completely defined primary outcomes reported in registry entries, preprints, and journal articles, and to assess consistent primary outcome reporting between these sources. Methods: This is a descriptive study of a cohort of registered interventional clinical trials for the treatment and prevention of COVID-19, drawn from the DIssemination of REgistered COVID-19 Clinical Trials (DIRECCT) study dataset. The main outcomes are: 1) Prevalence of complete primary outcome reporting; 2) Prevalence of consistent primary outcome reporting between registry entry and preprint as well as registry entry and journal article pairs. Results: We analyzed 87 trials with 116 corresponding publications (87 registry entries, 53 preprints and 63 journal articles). All primary outcomes were completely defined in 47/87 (54%) registry entries, 31/53 (58%) preprints and 44/63 (70%) journal articles. All primary outcomes were consistently reported in 13/53 (25%) registry-preprint pairs and 27/63 (43%) registry-journal article pairs. No primary outcome was specified in 13/53 (25%) preprints and 8/63 (13%) journal articles. In this sample, complete primary outcome reporting occurred more frequently in trials with vs. without involvement of pharmaceutical companies (76% vs. 45%), and in RCTs vs. other study designs (68% vs. 49%). The same pattern was observed for consistent primary outcome reporting (with vs. without pharma: 56% vs. 12%, RCT vs. other: 43% vs. 22%). Conclusions: In COVID-19 trials in the early phase of the pandemic, all primary outcomes were completely defined in 54%, 58%, and 70% of registry entries, preprints and journal articles, respectively. Only 25% of preprints and 43% of journal articles reported primary outcomes consistent with registry entries

Применение дуговой сварки при ремонте ковшей экскаваторов в условиях Крайнего Севера

Цель работы – разработка технологии ремонта ковшей экскаваторов ручной дуговой наплавкой в условиях Крайнего Севера. В процессе исследования установлена основная причина выхода их из строя зубьев ковшей, описаны свойства стали 110Г13Л, отражены причины плохой свариваемости стали и меры по снижению сварочных деформаций, подобран оптимальный способ наплавки, сварочное оборудование и наплавочные материалы для работы в условиях низких температур, рассчитаны параметры режима наплавки. В результате исследования разработана технология ремонта ковшей экскаваторов ручной дуговой наплавкой покрытыми электродами в условиях Крайнего Севера.The purpose of the work is to develop a technology for repair of excavators buckets by manual arc welding in the Far North. In the course of the study, the main reason for their failure of the bucket teeth is established, the properties of 110G13L steel are described, the causes of poor weldability of steel and measures to reduce welding deformations are reflected, the optimal method of surfacing, welding equipment and surfacing materials for operation at low temperatures are selected, the parameters of the surfacing mode are calculated. As a result of the study, the technology of repair of excavators buckets by manual arc welding with covered electrodes in the Far North was developed

Multimodal imaging techniques to evaluate the anticancer effect of cold atmospheric pressure plasma

Background: Skin cancer is the most frequent cancer worldwide and is divided into non-melanoma skin cancer, including basal cell carcinoma, as well as squamous cell carcinoma (SCC) and malignant melanoma (MM). Methods: This study evaluates the effects of cold atmospheric pressure plasma (CAP) on SCC and MM in vivo, employing a comprehensive approach using multi-modal imaging techniques. Longitudinal MR and PET/CT imaging were performed to determine the anatomic and metabolic tumour volume over three‐weeks in vivo. Additionally, the formation of reactive species after CAP treatment was assessed by non‐invasive chemiluminescence imaging of L‐012. Histological analysis and immunohistochemical staining for Ki‐67, ApopTag®, F4/80, CAE, and CD31, as well as protein expression of PCNA, caspase‐3 and cleaved‐caspase‐3, were performed to study proliferation, apoptosis, inflammation, and angiogenesis in CAP‐treated tumours. Results: As the main result, multimodal in vivo imaging revealed a substantial reduction in tumour growth and an increase in reactive species after CAP treatment, in comparison to untreated tu-mours. In contrast, neither the markers for apoptosis, nor the metabolic activity of both tumour entities was affected by CAP. Conclusions: These findings propose CAP as a potential adjuvant therapy option to established standard therapies of skin cancer