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Circadian Rhythms in Plasticity Markers Are Regulated by the Suprachiasmatic Nucleus and Local Circadian Oscillators in the Rodent Neocortex
No full textCircadian rhythms in clock gene expression are a global feature of neurons. While clock gene products have been shown to modulate plasticity at the synapse level, little is known about molecular circadian rhythms in neuroplasticity. In this study, we aim to establish circadian regulatory mechanisms of plasticity in the rat cerebral cortex. We show that the expression of the plasticity markers activity-regulated cytoskeleton-associated protein (Arc), brain-derived neurotrophic factor (Bdnf), and early growth response protein 1 (Egr1) exhibits marked circadian rhythms with increasing transcript levels during nighttime in the adult neocortex, but not in the hippocampus. Rhythmic expression of plasticity markers was restricted to postnatal stages. Lesion studies showed that rhythmic Arc, Bdnf, and Egr1 expression in the neocortex is regulated by the suprachiasmatic nucleus (SCN). High nocturnal Arc levels were partly restored by rhythmic subcutaneous infusion of corticosterone via an implanted programmable pump though without restoring rhythmic gene expression. Additionally, we show that the normal circadian Arc expression profile in the neocortex of cortex-specific Bmal1 clock gene knockout mice was disrupted compared to controls. In conclusion, our work suggests that the neuroplasticity of the neocortex exhibits circadian rhythmicity reflected by rhythmic plasticity markers controlled by a combination of the central clock of the SCN and the local circadian oscillator of the cerebral cortex.</p
Estimating the size of foodborne outbreaks from human genomic surveillance data
No full textWhole genome sequencing (WGS) data are increasingly used for the surveillance of foodborne infections and their genetic clusters in humans, leading to the detection of more potential outbreaks that require an intervention. We present a method based on probability theory that provides operationally relevant statistics about the size of a genetic cluster, including an estimate of the real cluster size in the population, its related uncertainty and the probability that the real size exceeds a predefined threshold. The method also allows identifying large clusters, based on the number of isolates that are genetically related, and predefined operational thresholds for their size. Finally, this method allows monitoring the evolution of the real size of an outbreak over time. We use simulated scenarios and real-life examples of previously identified genetic clusters of human campylobacteriosis in Denmark to illustrate how operational questions can be answered. We provide reference tables that the reader can apply in various contexts. Our method and findings can be used i) to quantify the real size of a foodborne outbreak with a predefined certainty; ii) to support decision making in identifying the foodborne outbreaks that require an intervention and to back up communication to authorities, the industry and the public; iii) to assess the capacities of a WGS-based surveillance system of foodborne infections to identify relevant outbreaks in consideration of the number of sequenced isolates out of the total number of reported infections.Whole genome sequencing (WGS) data are increasingly used for the surveillance of foodborne infections and their genetic clusters in humans, leading to the detection of more potential outbreaks that require an intervention. We present a method based on probability theory that provides operationally relevant statistics about the size of a genetic cluster, including an estimate of the real cluster size in the population, its related uncertainty and the probability that the real size exceeds a predefined threshold. The method also allows identifying large clusters, based on the number of isolates that are genetically related, and predefined operational thresholds for their size. Finally, this method allows monitoring the evolution of the real size of an outbreak over time. We use simulated scenarios and real-life examples of previously identified genetic clusters of human campylobacteriosis in Denmark to illustrate how operational questions can be answered. We provide reference tables that the reader can apply in various contexts. Our method and findings can be used i) to quantify the real size of a foodborne outbreak with a predefined certainty; ii) to support decision making in identifying the foodborne outbreaks that require an intervention and to back up communication to authorities, the industry and the public; iii) to assess the capacities of a WGS-based surveillance system of foodborne infections to identify relevant outbreaks in consideration of the number of sequenced isolates out of the total number of reported infections.</p
Relationship between poverty and symptoms of depression and anxiety among adolescents in Nepal:Examining the mediating effect of external and internal resilience
No full textObjectiveThis study aimed to examine the mediating effect of two types of resilience (internal, with factors such as problem solving and perseverance, and external resilience, with factors such as social support and sense of belonging) among adolescents affected by family poverty in Nepal in relation to symptoms of depression and anxiety.MethodsParticipants identified as living in deprived conditions (n = 491) in a cross-sectional survey completed measures about poverty, depressive and anxiety symptoms, and external and internal resilience. Mediation analyses were performed using poverty scores as the predictor, internal and external resilience as mediators, and depression and anxiety scores as outcomes, tested through parallel and serial mediation models.ResultsExternal resilience emerged as the only pathway across both parallel and serial mediation models. External resilience showed significant indirect effects for both depression (β = 0.797, 95 % CI: 0.181–1.677) and anxiety (β = 0.557, 95 % CI: 0.101–1.237). No sequential mediation was found. Although the total association of poverty with depression and anxiety was not significant—likely due to participants' homogeneity in poverty—external resilience accounted for 54.33 % of the association with depression and 31.61 % with anxiety, contributing to total indirect effects of 66.79 % and 38.25 %, respectively.ConclusionsThis study expands the evidence on the mediating effect of external resilience in the association between poverty and depression and anxiety in Nepali adolescents. The mediating effect was stronger for depressive outcomes than for anxiety. Factors of external resilience are discussed as a critical target for mental health interventions among adolescents living in poverty.Objective This study aimed to examine the mediating effect of two types of resilience (internal, with factors such as problem solving and perseverance, and external resilience, with factors such as social support and sense of belonging) among adolescents affected by family poverty in Nepal in relation to symptoms of depression and anxiety. Methods Participants identified as living in deprived conditions ( n = 491) in a cross-sectional survey completed measures about poverty, depressive and anxiety symptoms, and external and internal resilience. Mediation analyses were performed using poverty scores as the predictor, internal and external resilience as mediators, and depression and anxiety scores as outcomes, tested through parallel and serial mediation models. Results External resilience emerged as the only pathway across both parallel and serial mediation models. External resilience showed significant indirect effects for both depression (β = 0.797, 95 % CI: 0.181–1.677) and anxiety (β = 0.557, 95 % CI: 0.101–1.237). No sequential mediation was found. Although the total association of poverty with depression and anxiety was not significant—likely due to participants' homogeneity in poverty—external resilience accounted for 54.33 % of the association with depression and 31.61 % with anxiety, contributing to total indirect effects of 66.79 % and 38.25 %, respectively. Conclusions This study expands the evidence on the mediating effect of external resilience in the association between poverty and depression and anxiety in Nepali adolescents. The mediating effect was stronger for depressive outcomes than for anxiety. Factors of external resilience are discussed as a critical target for mental health interventions among adolescents living in poverty.</p
Resistive relativistic magnetohydrodynamics without Ampere's law
No full textResistive magnetohydrodynamics is thought to play a key role in transient high-energy astrophysical phenomena such as flares from black hole and neutron star magnetospheres. When performing numerical simulations of resistive magnetohydrodynamics, one is faced with the issue that Ampe`re's law becomes stiff in the high conductivity limit which poses challenges to the numerical evolution. We show that using a description of resistive magnetohydrodynamics based on higher-form symmetry, one can perform simulations with a generalized dual Faraday tensor without having to use Ampe`re's law, thereby avoiding the stiffness problem. We also explain the relation of this dual model to a traditional description of resistive magnetohydrodynamics and how causality is guaranteed by introducing second order corrections
Environmental DNA/RNA for non-invasive early detection and monitoring of pathogen dynamics in Atlantic salmon (<i>Salmo salar</i>) recirculating aquaculture systems (RAS)
No full textRecirculating Aquaculture Systems (RAS) provide efficient fish production with reduced water use and precise environmental control. However, their closed design facilitates susceptibility to pathogen persistence and disease outbreaks, highlighting the need for effective monitoring and treatments. Over a 12-week study, water samples (purified eDNA/eRNA) were evaluated in two freshwater RAS units at a commercial pre-smolt Atlantic salmon (Salmo salar) farm as a non-lethal and non-invasive alternative to tissue samples for early pathogen detection. A key aim was furthermore to elucidate the infection dynamics by monitoring five pathogens: salmon gill poxvirus (SGPV), non-virulent infectious salmon anaemia virus (ISAV-HPR0), infectious pancreatic necrosis virus (IPNV), piscine orthoreovirus genotype 1 (PRV-1), and the bacterium Flavobacterium psychrophilum. The study revealed similar sequential infection patterns of the four viral pathogens in both RAS units, starting with clinical infection by SGPV, followed by infection with ISAV-HPR0, alongside a concurrent clinical infection with IPNV and sporadic PRV-1 detections. SGPV peaked earlier and caused higher mortality in one system, consistent with elevated SGPV levels detected in water prior to fish transfer. A strong positive correlation was found between gill swabs and water samples for SGPV and ISAV-HPR0. Although high viral loads of IPNV were recorded in fish in one system, with sporadic detections in the other, no consistent correlation could be established between kidney swabs and water samples. No correlation was seen for PRV-1 as well. F. psychrophilum showed minor fluctuations in gill swabs but higher, yet stable, levels in water samples. Our study elucidates the infection dynamics of key Atlantic salmon pathogens in RAS and demonstrates the potential of eDNA/eRNA as a non-invasive tool for the prediction, early detection, and monitoring of SGPV and ISAV-HPR0 in Atlantic salmon RAS.</p
Distribution of forest-based innovations across Europe
No full textVast majority of forestry research on innovations is based on case studies, which makes it difficult to ascertain their distribution across Europe. The relation between innovating activity and the forest within which it takes place is also an under-explored research area. In this study, we address these problems by combining survey data, spatially explicit datasets and machine learning to devise geographical probability distribution of innovation development across Europe. We differentiate between innovations focused on provision of wood and those which focus on biodiversity protection, carbon storage and forest recreation. We also show that most of the variability in the data depicting innovation development can be explained by place-based variables, such as the amount of tree biomass in the forest, tree species composition, nature protection status, terrain ruggedness and road density. Results suggest the need to further explore the role of ‘place-based’ contextual variables in innovation development and highlight various issues that different policies might face when aiming to modify forest management practices in Europe.</p
Unveiling the nature of glassy impact spherules by analyzing pristine Chicxulub spherules from Gorgonilla Island
No full textThe Chicxulub impact triggered a massive extinction event marked by the Cretaceous-Paleogene boundary (K-Pg ∼66Ma), ejecting vast amounts of dust, molten, and vaporized materials. While impact spherules are interpreted as products of impactor and target lithologies, their precise composition and distribution remain insufficiently constrained. Although previous studies restrict impactor contamination to the condensed spherules from the fireball layer and the K-Pg boundary clay, here we show asteroid contribution to the composition of large spherules from the base of the K-Pg bed. Despite those spherules displaying an apparent immiscible bimodal composition of yellow (Ca-rich) and black (Si-rich) glasses, novel nano-resolution analyses demonstrate enrichment of elements derived from the impactor. By analyzing pristine spherules from the normally-graded sequence of Gorgonilla Island K-Pg site, our results show the presence of metals and platinum group elements (PGEs) in glasses and vesicles within large molten spherules. Furthermore, needle-like and cubic-shaped nanostructures co-localizing Pt, Co, Ni, and Pb, and Cu, Os, and Zn, may represent the first evidence of quasicrystals (quasi-periodic solids, not found in terrestrial rocks, with symmetries forbidden for crystals) in Chicxulub-derived deposits. Those nanostructures challenge the definitions of microtektites and microkrystites, suggesting these classifications are misleading. We recommend abandoning such terminology, preserving the generic term "impact spherules," irrespective of composition, morphology, or size. Our findings contribute to refining the classification and interpretation of impact spherules, advancing our understanding of the processes underlying hypervelocity impacts. Moreover, these insights may hold relevance not only for terrestrial impacts but also for analogous extraterrestrial contexts.</p
Educational inequalities in stroke knowledge and symptom recognition following a national Danish stroke campaign:a cross-sectional study
No full textINTRODUCTION: Public stroke campaigns may have informational gaps, which are essential to identify to improve outcomes in stroke awareness and response. We evaluated the impact of a national stroke campaign on knowledge of stroke, and symptom recognition, in relation to educational level.METHODS: Six cross-sectional post-campaign surveys were conducted (2019-2022) using a Danish responder panel (n = 2000 first survey, n = 1000 each of the following) after the launch of a stroke awareness campaign. Using logistic regression analysis we tested associations between campaign recall and each of the three parameters: knowledge of stroke, symptom recognition, and knowledge of correct call-to-action. Analyses were stratified by educational level.RESULTS: Of 7001 individuals (56.7% women) 44.8% recalled the campaign during the period, and knowledge of stroke, symptom recognition and correct call-to-action increased over time. Campaign recall was associated with increased knowledge of stroke (OR: 1.57, 95% CI: 1.42-1.74) and symptom recognition (OR: 2.11, 95% CI: 1.89-2.36). The stratified analyses showed that individuals with a master's degree had higher OR for symptom recognition (OR: 2.59 95% Cl: 1.95-3.44) compared to individuals with vocational education (OR 1.93, 95% Cl: 1.59-2.35).CONCLUSIONS: Initiation of a national stroke campaign was associated with improved knowledge of stroke and symptom recognition. Among individuals with lower educational level the association between campaign recall and recognition of stroke symptoms appeared weaker. The impact of educational levels may be considered in the design of future stroke campaigns. Whether stroke recognition and knowledge of correct call-to-action translate into appropriate responses remains to be fully evaluated.INTRODUCTION: Public stroke campaigns may have informational gaps, which are essential to identify to improve outcomes in stroke awareness and response. We evaluated the impact of a national stroke campaign on knowledge of stroke, and symptom recognition, in relation to educational level.METHODS: Six cross-sectional post-campaign surveys were conducted (2019-2022) using a Danish responder panel (n = 2000 first survey, n = 1000 each of the following) after the launch of a stroke awareness campaign. Using logistic regression analysis we tested associations between campaign recall and each of the three parameters: knowledge of stroke, symptom recognition, and knowledge of correct call-to-action. Analyses were stratified by educational level.RESULTS: Of 7001 individuals (56.7% women) 44.8% recalled the campaign during the period, and knowledge of stroke, symptom recognition and correct call-to-action increased over time. Campaign recall was associated with increased knowledge of stroke (OR: 1.57, 95% CI: 1.42-1.74) and symptom recognition (OR: 2.11, 95% CI: 1.89-2.36). The stratified analyses showed that individuals with a master's degree had higher OR for symptom recognition (OR: 2.59 95% Cl: 1.95-3.44) compared to individuals with vocational education (OR 1.93, 95% Cl: 1.59-2.35).CONCLUSIONS: Initiation of a national stroke campaign was associated with improved knowledge of stroke and symptom recognition. Among individuals with lower educational level the association between campaign recall and recognition of stroke symptoms appeared weaker. The impact of educational levels may be considered in the design of future stroke campaigns. Whether stroke recognition and knowledge of correct call-to-action translate into appropriate responses remains to be fully evaluated.</p
Mild hydrotreatment as a stabilization step for nitrogen-rich sewage sludge biocrude in a pilot-scale trickle-bed reactor
No full textBiocrude from sewage sludge contains high levels of nitrogen- and oxygen, making it unstable and unsuitable for direct use as fuel. This study investigates mild hydrotreatment as a stabilization step using a sulfided commercial NiMo/Al2O3 catalyst in a pilot-scale trickle-bed reactor. Treatments were performed at 200–280 °C and 120 barg with liquid hourly space velocities (LHSV), ranging from 0.5 to 2 h−1. Elemental analysis showed efficient chlorine and sulfur removal (up to 85 % and 60 %, respectively) and 51 % oxygen removal, while nitrogen remained persistent with less than 25 % conversion at 280 °C. Micro carbon residue (MCR) decreased with temperatures up to 240 °C, indicating stabilization, but increased at higher temperatures due to oligomerization. Simulated distillation confirmed formation of heavier fractions above 240 °C. LHSV had a smaller effect, suggesting potential for increased throughput. Supercritical fluid chromatography-high-resolution mass spectrometry (SFC-HRMS) revealed removal of quinolines and methoxy-oxygenates, with concurrent formation of amines and fatty acid amides. Mild hydrotreatment at 240 °C effectively reduced chemical reactivity while preserving catalytic integrity and process stability. The results establish process boundaries for industrial stabilization of nitrogen-rich biocrudes and support staged upgrading strategies for full fuel conversion.</p