613 research outputs found

    COVID-19, post-acute COVID-19 syndrome (PACS, "long COVID") and post-COVID-19 vaccination syndrome (PCVS, "post-COVIDvac-syndrome"): Similarities and differences

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    Worldwide there have been over 760 million confirmed coronavirus disease 2019 (COVID-19) cases, and over 13 billion COVID-19 vaccine doses have been administered as of April 2023, according to the World Health Organization. An infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can lead to an acute disease, i.e. COVID-19, but also to a post-acute COVID-19 syndrome (PACS, "long COVID"). Currently, the side effects of COVID-19 vaccines are increasingly being noted and studied. Here, we summarise the currently available indications and discuss our conclusions that (i) these side effects have specific similarities and differences to acute COVID-19 and PACS, that (ii) a new term should be used to refer to these side effects (post-COVID-19 vaccination syndrome, PCVS, colloquially "post-COVIDvac-syndrome"), and that (iii) there is a need to distinguish between acute COVID-19 vaccination syndrome (ACVS) and post-acute COVID-19 vaccination syndrome (PACVS) - in analogy to acute COVID-19 and PACS ("long COVID"). Moreover, we address mixed forms of disease caused by natural SARS-CoV-2 infection and COVID-19 vaccination. We explain why it is important for medical diagnosis, care and research to use the new terms (PCVS, ACVS and PACVS) in order to avoid confusion and misinterpretation of the underlying causes of disease and to enable optimal medical therapy. We do not recommend to use the term "Post-Vac-Syndrome" as it is imprecise. The article also serves to address the current problem of "medical gaslighting" in relation to PACS and PCVS by raising awareness among the medical professionals and supplying appropriate terminology for disease

    A meta-analysis examining how fish biodiversity varies with marine protected area size and age

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    Marine protected areas (MPAs) are a well-established conservation practice worldwide, but their effectiveness in protecting or replenishing fish biodiversity remains uneven. Understanding the patterns of this heterogeneity is central to general guidelines for MPA design and can ultimately provide guidance on how to maximize MPA potential. Here, we examine associations between the degree of protection, duration of protection, and protected area size, with fish biodiversity inside of protected areas relative to that of sites nearby, but outside of protected areas. We quantitatively synthesize 116 published estimates of species richness from 72 MPAs and 38 estimates of Shannon entropy from 21 MPAs. We show that species richness is on average 18% (95% CIs: 10%–29%) higher in protected areas than in areas open to fishing; on average, Shannon entropy is 13% (95% CIs: −2% to 31%) higher within protected areas relative to outside. We find no relationship between the degree and duration of protection with the ratio of species richness inside versus outside of protected areas; both fully and partially protected areas contribute to the accumulation of species inside of protected areas, and protected areas of all ages contribute similarly on average to biodiversity conservation. In contrast to our expectations, increasing protected area size was associated with a decreased ratio of species richness sampled at sites inside versus outside of the protected area, possibly due, for example, to insufficient enforcement and/or low compliance. Finally, we discuss why meta-analyses such as ours that summarize effect sizes of local scale biodiversity responses, that is, those at a single site, can only give a partial answer to the question of whether larger protected areas harbor more species than comparable unprotected areas

    Octave bandwidth S- and C-band GaN-HEMT power amplifiers for future 5G communication

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    Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.In this contribution, a design methodology for octave-bandwidth power amplifiers (PA) for 5G communication systems using surface mount dual-flat-no-lead packaged gallium-nitride high-electron-mobility transistor devices is presented. Systematic source- and load-pull simulations have been used to find the optimum impedances across 75% fractional bandwidth for S- (1.9–4.2 GHz) and C-band (3.8–8.4 GHz) PAs. The harmonic impact is considered to improve the output power and efficiency of the PAs. Utilizing the characteristic behavior of the transistors leads to modified optimum fundamental load impedances for the low-frequency range, which have higher gain compared with high-frequency range, and minimize the influence of the higher harmonics. Continuous wave large-signal measurements of the realized S-Band PA show a power added efficiency (PAE) of more than 40% from 1.9–4.2 GHz and a flat power gain of 11 dB while achieving a saturated output power of 10 W. The measured performance of the C-Band PA demonstrates a delivered power between 3.5 and 5 W across the frequency range of 3.8–8.4 GHz. A flat power gain of around 9 ± 0.5 dB with 26–40% PAE is achieved

    Hope, Politics and Risk: The Case of Chinese Dam in Nigeria

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    The rise of Chinese infrastructure investment in Africa has raised a set of questions about whose development agendas are being fulfilled by such projects, where the power lies in these negotiations, and how local communities are impacted by the projects. Current assumptions see China as holding the power in these relations and that its state-backed transnational corporations unilaterally get their way. This paper challenges these simplistic assumptions by examining the case of a ‘failed’ Chinese project - the Zamfara Dam in Northern Nigeria – and in doing so makes a case for the role of African political agency in brokering Chinese engagement. The dam project was initiated in 2008 between the Zamfara State government and the China Geo-Engineering Corporation; funding was supposed to come from the Chinese ExIm Bank. After the initial assessment and community consultations that spanned three years, the project failed to take off. Primary data is used to understand the process of failure and shows that the dam was initiated based on political expediency rather than the actual drive for development. It was brokered between the elites of China, Nigeria and Zamfara state and so failed to gain wider legitimacy and accountability. Also, in the drive to see the project initiated statutory shortcuts were taken. Critically, consultation was not broadbased even among the state government officials and the communities. The initiation of the project did not follow the laid down procedure of the Federal Ministry of Water Resources. Given that largely political factors played a significant role in the failure of the project, it is suggested that motivation for and implementation of development projects of this nature should transcend political whims and caprices of politicians and ensuring more transparency and broad consultation

    A Partitioned Likelihood Analysis of Swallowtail Butterfly Phylogeny (Lepidoptera: Papilionidae)

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    Although it is widely agreed that data from multiple sources are necessary to confidently resolve phylogenetic relationships, procedures for accommodating and incorporating heterogeneity in such data remained underdeveloped. We explored the use of partitioned, model-based analyses of heterogeneous molecular data in the context of a phylogenetic study of swallowtail butterflies (Lepidoptera: Papilionidae)

    Two-dimensional analysis of the double-resonant 2D Raman mode in bilayer graphene

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    By computing the double-resonant Raman scattering cross-section completely from first principles and including electron-electron interaction at the GWGW level, we unravel the dominant contributions for the double-resonant 2D-mode in bilayer graphene. We show that, in contrast to previous works, the so-called inner processes are dominant and that the 2D-mode lineshape is described by three dominant resonances around the KK point. We show that the splitting of the TO phonon branch in Γ−K\Gamma-K direction, as large as 12 cm−1^{-1} in GWGW approximation, is of great importance for a thorough description of the 2D-mode lineshape. Finally, we present a method to extract the TO phonon splitting and the splitting of the electronic bands from experimental data.Comment: 5 pages Main + 6 pages Supplementary Material. Accepted for publication in Physical Review Letter

    While shoot herbivores reduce, root herbivores increase nutrient enrichment’s impact on diversity in a grassland model

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    Nutrient enrichment is widespread throughout grassland systems and expected to increase during the Anthropocene. Trophic interactions, like aboveground herbivory, have been shown to mitigate its effect on plant diversity. Belowground herbivory may also impact these habitats’ response to nutrient enrichment, but its influence is much less understood, and likely to depend on factors such as the herbivores’ preference for dominant species and the symmetry of belowground competition. If preferential toward the dominant, fastest growing species, root herbivores may reduce these species’ relative fitness and support diversity during nutrient enrichment. However, as plant competition belowground is commonly considered to be symmetric, root herbivores may be less impactful than shoot herbivores because they do not reduce any competitive asymmetry between the dominant and subordinate plants. To better understand this system, we used an established, two-layer, grassland community model to run a full-factorially designed simulation experiment, crossing the complete removal of aboveground herbivores and belowground herbivores with nutrient enrichment. After 100 yr of simulation, we analyzed communities' diversity, competition on the individual level, as well as their resistance and recovery. The model reproduced both observed general effects of nutrient enrichment in grasslands and the short-term trends of specific experiments. We found that belowground herbivores exacerbate the negative influence of nutrient enrichment on Shannon diversity within our model grasslands, while aboveground herbivores mitigate its effect. Indeed, data on individuals’ above- and belowground resource uptake reveals that root herbivory reduces resource limitation belowground. As with nutrient enrichment, this shifts competition aboveground. Since shoot competition is asymmetric, with larger, taller individuals gathering disproportionate resources compared to their smaller, shorter counterparts, this shift promotes the exclusion of the smallest species. While increasing the root herbivores’ preferences toward dominant species lessens their negative impact, at best they are only mildly advantageous, and they do very little reduce the negative consequences of nutrient enrichment. Because our model’s belowground competition is symmetric, we hypothesize that root herbivores may be beneficial when root competition is asymmetric. Future research into belowground herbivory should account for the nature of competition belowground to better understand the herbivores’ true influence

    Interoperable Architecture For Logical Reconfigurations Of Modular Production Systems

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    Individualisation of products and ever-shorter product lifecycles require manufacturing companies to quickly reconfigure their production and adapt to changing requirements. While most of the existing literature focuses on organisational structures or hardware requirements for reconfigurability, requirements and best practices for logical reconfigurations of automated production systems are only sparsely covered. In practice, logical system reconfigurations require adjustments to the software, which is often done manually by experts. With the ongoing automation and digitisation of manufacturing systems in the context of Industry4.0, the need for automated software reconfigurations is increasing. However, heterogeneous and proprietary technologies in the field of industrial automation pose a hurdle to overcome for generally applicable approaches for logical reconfigurations in the industrial domain. Therefore, this paper reviews available technologies that can be used to solve the problem of automated software reconfigurations. For this purpose, an architecture and a procedure are proposed on how to use these technologies for automatic adaptation and virtual commissioning of control software in industrial automation. To demonstrate the interoperability of the approach, collective cloud manufacturing is used as a composing platform. The presented approach further includes a domain-specific capability model for the specification of software artefacts to be generated, allowing jobs to be described and matched on the platform. The core element is a code generator for generating and orchestrating the control code for process execution using the reconfigurable digital twin as a validator on the platform. The approach is evaluated and demonstrated in a real-world use case of a modular disassembly station
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