Purpose The identification of patients infected by SARS-CoV-2 is highly important to control the disease; however, the clinical presentation is often unspecific and a large portion of the patients develop mild or no symptoms at all. For this reason, there is an emphasis on evaluating diagnostic tools for screening. Chest CT scans are emerging as a useful tool in the diagnostic process of viral pneumonia cases associated with COVID-19. This review examines the sensitivity, specificity, and feasibility of chest CT in detecting COVID-19 compared with real-time polymerase chain reaction (RT-PCR). Methods Sensitivity and specificity of chest CT in detecting COVID-19 in its various phases was compared using RT-PCR as a gold standard. A “reverse calculation approach” was applied and treated chest CT as a hypothetical gold standard and compared RT-PCR to it point out the flaw of the standard approach. Results High sensitivity (67–100%) and relatively low specificity (25–80%) was reported for the CT scans. However, the sensitivity of RT-PCR was reported to be modest (53–88%), hence cannot serve as an appropriate ground truth. The “reverse calculation approach” showed that CT could have a higher specificity (83–100%) if we consider the modest sensitivity of the RT-PCR. Conclusions The sensitivity and specificity of the chest CT in diagnosing COVID-19 and the radiation exposure have to be judged together. Arguments are presented that chest CT scans have added value in diagnosing COVID-19 especially in patients, who exhibit typical clinical symptoms and have negative RT-PCR results in highly infected regions. Key Points • CT scans have higher specificity if we take into account the low sensitivity of the RT-PCR. • Avoid chest CT as a sole diagnostic approach for COVID-19 infection. • Patients who had negative RT-PCR result with typical clinical symptoms in highly infected regions or with close contact of COVID-19-infected patients; the use of chest CT is warranted.

In the past few decades, multiple theoretical studies have highlighted the diverse capabilities of freshwater fishpond systems in the provision of water-related ecosystem services (ESs). However, practical studies to confirm this statement are still lacking in the scientific literature compared to other ecosystems. In this paper, we reveal the ESs of three semi-intensively managed fishpond systems in Hungary and assess the knowledge and perceptions of local experts about them and their main interactions. Between 2017 and 2019, we performed participatory research on the fishpond systems of Biharugra, Akasztó, and Szeged, conducting a total of 22 structured interviews with experts from all related stakeholder groups. Based on the interviews, we identified 16 actively used ESs (4 provisioning, 7 regulating, and 5 cultural ESs) and also revealed 19 main forms of impacts (14 positive and 5 negative) related to them. Despite their different perceptions and demands associated with fish farms, almost every expert articulated the role of semi-intensive fish farming in the sustenance of water-related natural values and ecosystem services, endangered by the ongoing effects of global warming. Besides confirming the theoretical statements of previous studies, these findings could also provide information for subsequent land-use planning, with the aim of creating more sustainable, multifunctionally used fishpond systems.

Freshwater aquaculture has a significant role in fish production and biodiversity conservation. Due to climate change, however, the sustenance of fish farms became more challenging, endangering both people and natural values. The establishment of multi-purpose fishpond systems, utilizing ecosystem services besides fish production, could serve as a long-term solution for this problem. However, the lack of knowledge about fishponds’ ecosystem services creates an obstacle in the process. We would like to lower this barrier by mapping 13 different ecosystem services of White Lake, one of the most prominent fishpond systems in Hungary. The results of two different participatory mapping techniques indicated that standing waters, reedy areas, and canals, possessed the highest potential values in the provision of the listed ecosystem services, marking them as the most important areas for future developments. In the case of current sources, local experts linked the highest values to reedy areas and lookout towers. Participatory mapping also indicated that microclimate regulation and bird watching were the most widely used ecosystem services after fish production. By collecting and visualizing experts’ spatial data about White Lakes’ ecosystem services, our unique paper has the potential to serve future decision-making and provide a basis for further studies on this topic.