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The state of knowledge on the science and management of freshwater recreational fisheries is reviewed, with the objective of integrating insights from disparate fields such as fisheries science, environmental complexity theory, common-pool-resource theory, and resilience theory. First, freshwater recreational fisheries are characterized as complex adaptive social-ecological systems (SESs). Subsequently, two interrelated frameworks, drawing on the Ostrom framework for the analysis of SESs and adaptive management as key foundations, are presented. These frameworks are useful to structure the complexity and apprehend the various feedbacks and links inherent in any particular recreational fisheries system. Moreover, the frameworks help to identify operational management strategies in the face of substantial social-ecological uncertainty. It is concluded that to understand and manage freshwater recreational fisheries as complex adaptive SESs, a sustained shift from disciplinary to inter- and sometimes transdisciplinary research as well as a focus on flexible, adaptive and generally enabling rather than command-and-control type governance and management are needed. Understanding and managing recreational fisheries as complex adaptive SESs will benefit from an increasing focus on (i) managing social-ecological feedbacks and processes, (ii) managing critical slow variables that either drive the system or maintain it in potentially undesirable states, and (iii) managing and maintaining social and ecological diversity. It is hoped that the frameworks presented in this article may guide future interdisciplinary inquiry to manage for sustainability by building resilience. [ABSTRACT FROM AUTHOR]

Recreational specialisation theory was coupled with a discrete choice experiment to understand eel, Anguilla anguilla L., angler’s heterogeneity in their reaction to regulatory changes and the associated welfare changes. Differently specialised eel anglers exhibited distinct preferences for catch variables and eel angling regulations. All anglers preferred slightly to moderately stricter regulations than are currently in place; however, such policies particularly benefited casual eel anglers. In contrast, advanced eel anglers would be most penalised by highly restrictive regulations as indicated by substantial reductions in economic welfare. Aversions to stricter regulations found for advanced anglers contradicted predictions from specialisation theory. From an eel management perspective, the implementation of some simple tools such as increased minimum-size limits will reduce angling mortality on eel and simultaneously increase the welfare of anglers. By contrast, highly restrictive eel angling regulations will result in considerable economic welfare losses of several million € per year for northern Germany alone. [ABSTRACT FROM AUTHOR]

Objective: This study aimed to test the hypothesis that young adults with obesity and cold-activated brown adipose tissue (BAT) are less likely to have metabolic dysfunction (dyslipidemia, insulin resistance, and hypertension) than those without cold-activated BAT. Previous studies have noted a potentially protective effect of BAT and higher adiponectin/leptin ratios, but they have acknowledged that the clinical implications of these findings remain uncertain., Methods: Twenty-one females and twenty-three males with obesity (BMI ≥ 30 kg/m 2 ) underwent a 2-hour cooling protocol before 18 F-fluorodeoxyglucose ( 18 F-FDG)-positron emission tomography/x-ray computed tomography scan to determine the prevalence, volume, and  18 F-FDG uptake of cold-activated BAT., Results: Cold-activated BAT was identified in 43% of participants (11 female, 8 male); females had greater  18 F-FDG uptake. Those with cold-activated BAT had a lesser degree of metabolic dysfunction. Cold-activated BAT volume correlated with triglycerides (inversely) and adiponectin (concordantly). Body-mass-adjusted cold-activated BAT activity correlated with high-density lipoprotein cholesterol (concordantly). Males with cold-activated BAT had lower leptin and higher adiponectin/leptin ratio., Conclusions: A high prevalence of cold-activated BAT was found in the study participants. BAT could be important in decreasing metabolic dysfunction among young adults with obesity, making it a potential target for treating metabolically unhealthy obesity., (© 2020 The Obesity Society.)

Fish stocking and harvest regulations are frequently used to maintain or enhance freshwater recreational fisheries and contribute to fish conservation. However, their relative effectiveness has rarely been systematically evaluated using quantitative models that account for key size- and density-dependent ecological processes and adaptive responses of anglers. We present an integrated model of freshwater recreational fisheries where the population dynamics of two model species affect the effort dynamics of recreational anglers. With this model, we examined how stocking various fish densities and sizes (fry, fingerlings, and adults) performed relative to minimum-length limits using a variety of biological, social, and economic performance measures, while evaluating trade-offs. Four key findings are highlighted. First, stocking often augmented the exploited fish population, but size- and density-dependent bottlenecks limited the number of fry and fingerlings surviving to a catchable size in self-sustaining populations. The greatest enhancement of the catchable fish population occurred when large fish that escaped early bottlenecks were stocked, but this came at the cost of wild-stock replacement, thereby demonstrating a fundamental trade-off between fisheries benefits and conservation. Second, the relative performance of stocking naturally reproducing populations was largely independent of habitat quality and was generally low. Third, stocking was only economically advisable when natural reproduction was impaired or absent, stocking rates were low, and enough anglers benefitted from stocking to offset the associated costs. Fourth, in self-sustaining fish populations, minimum-length limits generally outperformed stocking when judged against a range of biological, social and economic objectives. By contrast, stocking in culture-based fisheries often generated substantial benefits. Collectively, our study demonstrates that size- and density-dependent processes, and broadly the degree of natural recruitment, drive the biological, social, and economic outcomes of popular management actions in recreational fisheries. To evaluate these outcomes and the resulting trade-offs, integrated fisheries-management models that explicitly consider the feedbacks among ecological and social processes are needed., (© 2018 by the Ecological Society of America.)

Background: Practice effects, which are improvements in cognitive test scores due to repeated exposure to testing materials, may provide information about Alzheimer's disease pathology, which could be useful for clinical trials enrichment., Objectives: The current study sought to add to the limited literature on short-term practice effects on cognitive tests and their relationship to amyloid deposition on neuroimaging., Participants: Twenty-seven, non-demented older adults (9 cognitively intact, 18 with mild cognitive impairment) received amyloid imaging with 18F-Flutemetamol, and two cognitive testing sessions across one week to determine practice effects., Results: A composite measure of 18F-Flutemetamol uptake correlated significantly with all seven cognitive tests scores on the baseline battery (r's = -0.61 - 0.59, all p's<0.05), with higher uptake indicating poorer cognition. Practice effects significantly added to the relationship (above and beyond the baseline associations) with 18F-Flutemetamol uptake on 4 of the 7 cognitive test scores (partial r's = -0.45 - 0.44, p's<0.05), with higher uptake indicating poorer practice effects. The odds ratio of being "amyloid positive" was 13.5 times higher in individuals with low practice effects compared to high practice effects., Conclusions: Short-term practice effects over one week may be predictive of progressive dementia and serve as an affordable screening tool to enrich samples for preventative clinical trials in Alzheimer's disease., Competing Interests: Conflict of Interest: Drs. Duff, Foster, and Hoffman received funding to support this project from GE Healthcare, who produces 18F-Flutemetamol.

Background: Metastatic renal cell carcinoma has a poor prognosis and an intrinsic resistance to standard treatment. Sunitinib is an oral receptor tyrosine kinase inhibitor that has been used as a first-line targeted therapy in metastatic renal cell carcinoma. While computed tomography (CT) is currently the gold standard for response assessment in oncological trials, numerous studies have shown that positron emission tomography (PET) imaging can provide information predictive of tumor response to treatment earlier than the typical interval for standard of care follow-up CT imaging. In this exploratory study we sought to characterize early tumor response in patients with metastatic renal cell carcinoma treated with continuous daily 37.5 mg sunitinib therapy., Methods: Twenty patients underwent dynamic acquisition positron emission tomography (PET) imaging using (18) F-fluorodeoxyglucose (FDG) and (18) F-fluorothymidine (FLT) at baseline and early in treatment (after 1, 2, 3 or 4 weeks) with 37.5 mg continuous daily dosing of sunitinib. Semi-quantitative analyses were performed to characterize the tumor metabolic (FDG) and proliferative (FLT) responses to treatment., Results: Proliferative responses were observed in 9/19 patients and occurred in 2 patients at one week (the earliest interval evaluated) after the initiation of therapy. A metabolic response was observed in 5/19 patients, however this was not observed until after two weeks of therapy were completed. Metabolic progression was observed in 2/19 patients and proliferative progression was observed in 1/19 patients. Baseline FDG-PET tumor maximum standardized uptake values correlated inversely with overall survival (p = 0.0036). Conversely, baseline (18) F-fluorothymidine PET imaging did not have prognostic value (p = 0.56) but showed a greater early response rate at 1-2 weeks after initiating therapy., Conclusions: While preliminary in nature, these results show an immediate and sustained proliferative response followed by a delayed metabolic response beginning after two weeks in metastatic renal cell carcinoma treated with a continuous daily dose of 37.5 mg sunitinib. The results provide evidence of tumor response to lower-dose sunitinib while also supporting the inclusion of PET imaging as a tool for early assessment in oncological clinical trials., Trial Registration: ID: NCT00694096.