1. |
- Adams, Nicholas, et al.
(författare)
-
El Niño Southern Oscillation, monsoon anomaly, and childhood diarrheal disease morbidity in Nepal
- 2022
-
Ingår i: PNAS Nexus. - : Oxford University Press (OUP). - 2752-6542. ; 1:2
-
Tidskriftsartikel (refereegranskat)abstract
- Climate change is adversely impacting the burden of diarrheal diseases. Despite significant reduction in global prevalence, diarrheal disease remains a leading cause of morbidity and mortality among young children in low- and middle-income countries. Previous studies have shown that diarrheal disease is associated with meteorological conditions but the role of large-scale climate phenomena such as El Niño-Southern Oscillation (ENSO) and monsoon anomaly is less understood. We obtained 13 years (2002–2014) of diarrheal disease data from Nepal and investigated how the disease rate is associated with phases of ENSO (El Niño, La Niña, vs. ENSO neutral) monsoon rainfall anomaly (below normal, above normal, vs. normal), and changes in timing of monsoon onset, and withdrawal (early, late, vs. normal). Monsoon season was associated with a 21% increase in diarrheal disease rates (Incident Rate Ratios [IRR]: 1.21; 95% CI: 1.16–1.27). El Niño was associated with an 8% reduction in risk while the La Niña was associated with a 32% increase in under-5 diarrheal disease rates. Likewise, higher-than-normal monsoon rainfall was associated with increased rates of diarrheal disease, with considerably higher rates observed in the mountain region (IRR 1.51, 95% CI: 1.19–1.92). Our findings suggest that under-5 diarrheal disease burden in Nepal is significantly influenced by ENSO and changes in seasonal monsoon dynamics. Since both ENSO phases and monsoon can be predicted with considerably longer lead time compared to weather, our findings will pave the way for the development of more effective early warning systems for climate sensitive infectious diseases.
|
|
2. |
- Agneman, Gustav, et al.
(författare)
-
Intergenerational altruism and climate policy preferences
- 2024
-
Ingår i: PNAS Nexus. - 2752-6542. ; 3:4, s. 1-11
-
Tidskriftsartikel (refereegranskat)abstract
- Climate mitigation constitutes an intergenerational moral dilemma; the decisions we make today will inevitably shape the prospects for generations to come. Yet, we still know little about the relationship between intergenerational altruism (IGA)-our concerns for the well-being of future generations-and support for costly climate mitigation policies. In this study, we present an approach to measuring IGA through an intergenerational dilemma, where participants allocate resources across generations. First, we describe how IGA depends on the temporal (social) distance between generations and demonstrate robust correlations between IGA and support for several climate policies. Then, we leverage randomized participation in the intergenerational dilemma to show that it causally increases climate policy support, an effect we attribute to higher worries about human-induced climate change among treated subjects. An exploratory heterogeneity analysis suggests that the impact of the intergenerational dilemma is primarily driven by female and nonbinary participants. In sum, this study presents both a novel measurement strategy and robust evidence of a malleable moral basis of climate policy preferences.
|
|
3. |
- Agneman, Gustav, et al.
(författare)
-
Intergenerational altruism and climate policy preferences
- 2024
-
Ingår i: PNAS NEXUS. - 2752-6542. ; 3:4
-
Tidskriftsartikel (refereegranskat)abstract
- Climate mitigation constitutes an intergenerational moral dilemma; the decisions we make today will inevitably shape the prospects for generations to come. Yet, we still know little about the relationship between intergenerational altruism (IGA)-our concerns for the well-being of future generations-and support for costly climate mitigation policies. In this study, we present an approach to measuring IGA through an intergenerational dilemma, where participants allocate resources across generations. First, we describe how IGA depends on the temporal (social) distance between generations and demonstrate robust correlations between IGA and support for several climate policies. Then, we leverage randomized participation in the intergenerational dilemma to show that it causally increases climate policy support, an effect we attribute to higher worries about human-induced climate change among treated subjects. An exploratory heterogeneity analysis suggests that the impact of the intergenerational dilemma is primarily driven by female and nonbinary participants. In sum, this study presents both a novel measurement strategy and robust evidence of a malleable moral basis of climate policy preferences.
|
|
4. |
- Bernardo, Carmela, et al.
(författare)
-
Quantifying leadership in climate negotiations: A social power game
- 2023
-
Ingår i: PNAS Nexus. - : National Academy of Sciences. - 2752-6542. ; 2:11
-
Tidskriftsartikel (refereegranskat)abstract
- We consider complex multistage multiagent negotiation processes such as those occurring at climate conferences and ask ourselves how can an agent maximize its social power, intended as influence over the outcome of the negotiation. This question can be framed as a strategic game played over an opinion dynamics model, in which the action of an agent consists in stubbornly defending its own opinion. We show that for consensus-seeking opinion dynamics models in which the interaction weights are uniform, the optimal action obeys to an early mover advantage principle, i.e. the agents behaving stubbornly in the early phases of the negotiations achieve the highest social power. When looking at data collected from the climate change negotiations going on at the United Nations Framework Convention on Climate Change, we find evidence of the use of the early mover strategy. Furthermore, we show that the social powers computed through our model correlate very well with the perceived leadership roles assessed through independent survey data, especially when non-uniform weights incorporating economical and demographic factors are considered.
|
|
5. |
- Bos, Meike F., et al.
(författare)
-
Goblet cell interactions reorient bundled mucus strands for efficient airway clearance
- 2023
-
Ingår i: PNAS Nexus. - 2752-6542. ; 2:11
-
Tidskriftsartikel (refereegranskat)abstract
- The respiratory tract of larger animals is cleared by sweeping bundled strands along the airway surface. These bundled strands can be millimetric in length and consist of MUC5B mucin. They are produced by submucosal glands, and upon emerging from these glands, the long axis of the bundled strands is oriented along the cilia-mediated flow toward the oral cavity. However, after release, the bundled strands are found to have turned orthogonal to the flow, which maximizes their clearance potential. How this unexpected reorientation is accomplished is presently not well understood. Recent experiments suggest that the reorientation process involves bundled strands sticking to MUC5AC mucus threads, which are tethered to the goblet cells. Such goblet cells are present in small numbers throughout the airway epithelium. Here, we develop a minimal model for reorientation of bundled mucus strands through adhesive interactions with surface goblet cells. Our simulations reveal that goblet cell interactions can reorient the bundled strands within 10 mm of release-making reorientation on the length scale of the tracheal tube feasible-and can stabilize the orthogonal orientation. Our model also reproduces other experimental observations such as strong velocity fluctuations and significant slow-down of the bundled strand with respect to the cilia-mediated flow. We further provide insight into the strand turning mechanism by examining the effect of strand shape on the impulse exerted by a single goblet cell. We conclude that goblet cell-mediated reorientation is a viable route for bundled strand reorientation, which should be further validated in future experiment.
|
|
6. |
- Di Clemente, Riccardo, et al.
(författare)
-
Understanding european integration with bipartite networks of comparative advantage
- 2022
-
Ingår i: PNAS Nexus. - : Oxford University Press. - 2752-6542. ; 1:5
-
Tidskriftsartikel (refereegranskat)abstract
- Core objectives of European common market integration are convergence and economic growth, but these are hampered by redundancy, and value chain asymmetries. The challenge is how to harmonize labor division to reach global competitiveness, meanwhile bridging productivity differences across the EU. We develop a bipartite network approach to trace pairwise co-specialization by applying the revealed comparative advantage method within and between the EU15 and Central and Eastern European (CEE). This approach assesses redundancies and the division of labor in the EU at the level of industries and countries. We find significant co-specialization among CEE countries but a diverging specialization between EU15 and CEE. Productivity increases in those CEE industries that have co-specialized with other CEE countries after EU accession, while co-specialization across CEE and EU15 countries is less related to productivity growth. These results show that a division of sectoral specialization can lead to productivity convergence between EU15 and CEE countries.
|
|
7. |
- Elsler, Laura G., 1987-, et al.
(författare)
-
Global trade network patterns are coupled to fisheries sustainability
- 2023
-
Ingår i: PNAS Nexus. - 2752-6542. ; 2:10
-
Tidskriftsartikel (refereegranskat)abstract
- The rapid development of seafood trade networks alongside the decline in biomass of many marine populations raises important questions about the role of global trade in fisheries sustainability. Mounting empirical and theoretical evidence shows the importance of trade development on commercially exploited species. However, there is limited understanding of how the development of trade networks, such as differences in connectivity and duration, affects fisheries sustainability. In a global analysis of over 400,000 bilateral trade flows and stock status estimates for 876 exploited fish and marine invertebrates from 223 territories, we reveal patterns between seafood trade network indicators and fisheries sustainability using a dynamic panel regression analysis. We found that fragmented networks with strong connectivity within a group of countries and weaker links between those groups (modularity) are associated with higher relative biomass. From 1995 to 2015, modularity fluctuated, and the number of trade connections (degree) increased. Unlike previous studies, we found no relationship between the number or duration of trade connections and fisheries sustainability. Our results highlight the need to jointly investigate fisheries and trade. Improved coordination and partnerships between fisheries authorities and trade organizations present opportunities to foster more sustainable fisheries.
|
|
8. |
- Eriksson, Kimmo, 1967-, et al.
(författare)
-
Cognitive ability and ideology join forces in the culture war : A model of opinion formation
- 2023
-
Ingår i: PNAS Nexus. - : National Academy of Sciences. - 2752-6542. ; 2:6
-
Tidskriftsartikel (refereegranskat)abstract
- We propose a model of moral policy opinion formation that integrates both ideology and cognitive ability. The link from people's ideology to their opinions is assumed to go via a semantic processing of moral arguments that relies on the individual's cognitive ability. An implication of this model is that the relative quality of arguments that justify supporting vs. opposing a moral policy-the policy's “argument advantage”-is key to how opinions will be distributed in the population and develop over time. To test this implication, we combine polling data with measures of the argument advantage for 35 moral policies. Consistent with the opinion formation model, the argument advantage of a moral policy accounts for how public opinion moves over time, and how support for the policy ideologies varies across different ideological groups and levels of cognitive ability, including a strong interaction between ideology and cognitive ability.
|
|
9. |
- Fontan, Angela, 1991-, et al.
(författare)
-
From populations to networks: Relating diversity indices and frustration in signed graphs
- 2024
-
Ingår i: PNAS Nexus. - : Oxford University Press (OUP). - 2752-6542. ; 3:2
-
Tidskriftsartikel (refereegranskat)abstract
- Diversity indices of quadratic type, such as fractionalization and Simpson index, are measures of heterogeneity in a population. Even though they are univariate, they have an intrinsic bivariate interpretation as encounters among the elements of the population. In the paper, it is shown that this leads naturally to associate populations to weakly balanced signed networks. In particular, the frustration of such signed networks is shown to be related to fractionalization by a closed-form expression. This expression allows to simplify drastically the calculation of frustration for weakly balanced signed graphs.
|
|
10. |
- Girard, Maxime, et al.
(författare)
-
Human-aided dispersal and population bottlenecks facilitate parasitism escape in the most invasive mosquito species
- 2024
-
Ingår i: PNAS NEXUS. - : Oxford University Press. - 2752-6542. ; 3:5
-
Tidskriftsartikel (refereegranskat)abstract
- During biological invasion process, species encounter new environments and partially escape some ecological constraints they faced in their native range, while they face new ones. The Asian tiger mosquito Aedes albopictus is one of the most iconic invasive species introduced in every inhabited continent due to international trade. It has also been shown to be infected by a prevalent yet disregarded microbial entomoparasite Ascogregarina taiwanensis. In this study, we aimed at deciphering the factors that shape the global dynamics of A. taiwanensis infection in natural A. albopictus populations. We showed that A. albopictus populations are highly colonized by several parasite genotypes but recently introduced ones are escaping it. We further performed experiments based on the invasion process to explain such pattern. To that end, we hypothesized that (i) mosquito passive dispersal (i.e. human-aided egg transportation) may affect the parasite infectiveness, (ii) founder effects (i.e. population establishment by a small number of mosquitoes) may influence the parasite dynamics, and (iii) unparasitized mosquitoes are more prompt to found new populations through active flight dispersal. The two first hypotheses were supported as we showed that parasite infection decreases over time when dry eggs are stored and that experimental increase in mosquitoes' density improves the parasite horizontal transmission to larvae. Surprisingly, parasitized mosquitoes tend to be more active than their unparasitized relatives. Finally, this study highlights the importance of global trade as a driver of biological invasion of the most invasive arthropod vector species.
|
|
11. |
- He, Lei, et al.
(författare)
-
Non-symmetric responses of leaf onset date to natural warming and cooling in northern ecosystems
- 2023
-
Ingår i: PNAS Nexus. - 2752-6542. ; 2:9
-
Tidskriftsartikel (refereegranskat)abstract
- The northern hemisphere has experienced regional cooling, especially during the global warming hiatus (1998-2012) due to ocean energy redistribution. However, the lack of studies about the natural cooling effects hampers our understanding of vegetation responses to climate change. Using 15,125 ground phenological time series at 3,620 sites since the 1950s and 31-year satellite greenness observations (1982-2012) covering the warming hiatus period, we show a stronger response of leaf onset date (LOD) to natural cooling than to warming, i.e. the delay of LOD caused by 1°C cooling is larger than the advance of LOD with 1°C warming. This might be because cooling leads to larger chilling accumulation and heating requirements for leaf onset, but this non-symmetric LOD response is partially offset by warming-related drying. Moreover, spring greening magnitude, in terms of satellite-based greenness and productivity, is more sensitive to LOD changes in the warming area than in the cooling. These results highlight the importance of considering non-symmetric responses of spring greening to warming and cooling when predicting vegetation-climate feedbacks.
|
|
12. |
- Lee, Yaerim, et al.
(författare)
-
Vibration sorting of small droplets on hydrophilic surface by asymmetric contact-line friction
- 2022
-
Ingår i: PNAS nexus. - : Oxford University Press. - 2752-6542. ; 1:2
-
Tidskriftsartikel (refereegranskat)abstract
- Droplet spreading and transport phenomenon is ubiquitous and has been studied by engineered surfaces with a variety of topographic features. To obtain a directional bias in dynamic wetting, hydrophobic surfaces with a geometrical asymmetry are generally used, attributing the directionality to one-sided pinning. Although the pinning may be useful for directional wetting, it usually limits the droplet mobility, especially for small volumes and over wettable surfaces. Here, we demonstrate a pinning-less approach to rapidly transport millimeter sized droplets on a partially wetting surface. Placing droplets on an asymmetrically structured surfaces with micron-scale roughness and applying symmetric horizontal vibration, they travel rapidly in one direction without pinning. The key, here, is to generate capillary-driven rapid contact-line motion within the time-scale of period of vibration. At the right regime where a friction factor local at the contact line dominates the rapid capillary motion, the asymmetric surface geometry can induce smooth and continuous contact-line movement back and forth at different speed, realizing directional motion of droplets even with small volumes over the wettable surface. We found that the translational speed is selective and strongly dependent on the droplet volume, oscillation frequency, and surface pattern properties, and thus droplets with a specific volume can be efficiently sorted out.
|
|
13. |
- Lee, Yaerim, et al.
(författare)
-
Vibration sorting of small droplets on hydrophilic surface by asymmetric contact-line friction
- 2022
-
Ingår i: PNAS Nexus. - : National Academy of Sciences. - 2752-6542. ; 1:2
-
Tidskriftsartikel (refereegranskat)abstract
- Droplet spreading and transport phenomenon is ubiquitous and has been studied by engineered surfaces with a variety of topographic features. To obtain a directional bias in dynamic wetting, hydrophobic surfaces with a geometrical asymmetry are generally used, attributing the directionality to one-sided pinning. Although the pinning may be useful for directional wetting, it usually limits the droplet mobility, especially for small volumes and over wettable surfaces. Here, we demonstrate a pinning-less approach to rapidly transport millimeter sized droplets on a partially wetting surface. Placing droplets on an asymmetrically structured surfaces with micron-scale roughness and applying symmetric horizontal vibration, they travel rapidly in one direction without pinning. The key, here, is to generate capillary-driven rapid contact-line motion within the time-scale of period of vibration. At the right regime where a friction factor local at the contact line dominates the rapid capillary motion, the asymmetric surface geometry can induce smooth and continuous contact-line movement back and forth at different speed, realizing directional motion of droplets even with small volumes over the wettable surface. We found that the translational speed is selective and strongly dependent on the droplet volume, oscillation frequency, and surface pattern properties, and thus droplets with a specific volume can be efficiently sorted out.
|
|
14. |
- Lu, Song, et al.
(författare)
-
Theory of transformation-mediated twinning
- 2023
-
Ingår i: PNAS NEXUS. - : Oxford University Press (OUP). - 2752-6542. ; 2:1
-
Tidskriftsartikel (refereegranskat)abstract
- High-density and nanosized deformation twins in face-centered cubic (fcc) materials can effectively improve the combination of strength and ductility. However, the microscopic dislocation mechanisms enabling a high twinnability remain elusive. Twinning usually occurs via continuous nucleation and gliding of twinning partial dislocations on consecutive close-packed atomic planes. Here we unveil a completely different twinning mechanism being active in metastable fcc materials. The transformation-mediated twinning (TMT) is featured by a preceding displacive transformation from the fcc phase to the hexagonal close-packed (hcp) one, followed by a second-step transformation from the hcp phase to the fcc twin. The nucleation of the intermediate hcp phase is driven by the thermodynamic instability and the negative stacking fault energy of the metastable fcc phase. The intermediate hcp structure is characterized by the easy slips of Shockley partial dislocations on the basal planes, which leads to both fcc and fcc twin platelets during deformation, creating more twin boundaries and further enhancing the prosperity of twins. The disclosed fundamental understanding of the complex dislocation mechanism of deformation twinning in metastable alloys paves the road to design novel materials with outstanding mechanical properties.
|
|
15. |
|
|
16. |
- Millán, Ana P., et al.
(författare)
-
Triadic percolation induces dynamical topological patterns in higher-order networks
- 2024
-
Ingår i: PNAS Nexus. - : Oxford University Press (OUP). - 2752-6542. ; 3:7
-
Tidskriftsartikel (refereegranskat)abstract
- Triadic interactions are higher-order interactions which occur when a set of nodes affects the interaction between two other nodes. Examples of triadic interactions are present in the brain when glia modulate the synaptic signals among neuron pairs or when interneuron axo-axonic synapses enable presynaptic inhibition and facilitation, and in ecosystems when one or more species can affect the interaction among two other species. On random graphs, triadic percolation has been recently shown to turn percolation into a fully fledged dynamical process in which the size of the giant component undergoes a route to chaos. However, in many real cases, triadic interactions are local and occur on spatially embedded networks. Here, we show that triadic interactions in spatial networks induce a very complex spatio-temporal modulation of the giant component which gives rise to triadic percolation patterns with significantly different topology. We classify the observed patterns (stripes, octopus, and small clusters) with topological data analysis and we assess their information content (entropy and complexity). Moreover, we illustrate the multistability of the dynamics of the triadic percolation patterns, and we provide a comprehensive phase diagram of the model. These results open new perspectives in percolation as they demonstrate that in presence of spatial triadic interactions, the giant component can acquire a time-varying topology. Hence, this work provides a theoretical framework that can be applied to model realistic scenarios in which the giant component is time dependent as in neuroscience.
|
|
17. |
- Müllender, Lukas, et al.
(författare)
-
Effective data-driven collective variables for free energy calculations from metadynamics of paths
- 2024
-
Ingår i: PNAS Nexus. - : Oxford University Press (OUP). - 2752-6542. ; 3:4
-
Tidskriftsartikel (refereegranskat)abstract
- A variety of enhanced sampling (ES) methods predict multidimensional free energy landscapes associated with biological and other molecular processes as a function of a few selected collective variables (CVs). The accuracy of these methods is crucially dependent on the ability of the chosen CVs to capture the relevant slow degrees of freedom of the system. For complex processes, finding such CVs is the real challenge. Machine learning (ML) CVs offer, in principle, a solution to handle this problem. However, these methods rely on the availability of high-quality datasets—ideally incorporating information about physical pathways and transition states—which are difficult to access, therefore greatly limiting their domain of application. Here, we demonstrate how these datasets can be generated by means of ES simulations in trajectory space via the metadynamics of paths algorithm. The approach is expected to provide a general and efficient way to generate efficient ML-based CVs for the fast prediction of free energy landscapes in ES simulations. We demonstrate our approach with two numerical examples, a 2D model potential and the isomerization of alanine dipeptide, using deep targeted discriminant analysis as our ML-based CV of choice.
|
|
18. |
- Nieves-Morión, Mercedes, et al.
(författare)
-
Heterologous expression of genes from a cyanobacterial endosymbiont highlights substrate exchanges with its diatom host
- 2023
-
Ingår i: PNAS Nexus. - 2752-6542. ; 2:6
-
Tidskriftsartikel (refereegranskat)abstract
- A few genera of diatoms are widespread and thrive in low-nutrient waters of the open ocean due to their close association with N2-fixing, filamentous heterocyst-forming cyanobacteria. In one of these symbioses, the symbiont, Richelia euintracellularis, has penetrated the cell envelope of the host, Hemiaulus hauckii, and lives inside the host cytoplasm. How the partners interact, including how the symbiont sustains high rates of N2 fixation, is unstudied. Since R. euintracellularis has evaded isolation, heterologous expression of genes in model laboratory organisms was performed to identify the function of proteins from the endosymbiont. Gene complementation of a cyanobacterial invertase mutant and expression of the protein in Escherichia coli showed that R. euintracellularis HH01 possesses a neutral invertase that splits sucrose producing glucose and fructose. Several solute-binding proteins (SBPs) of ABC transporters encoded in the genome of R. euintracellularis HH01 were expressed in E. coli, and their substrates were characterized. The selected SBPs directly linked the host as the source of several substrates, e.g. sugars (sucrose and galactose), amino acids (glutamate and phenylalanine), and a polyamine (spermidine), to support the cyanobacterial symbiont. Finally, transcripts of genes encoding the invertase and SBPs were consistently detected in wild populations of H. hauckii collected from multiple stations and depths in the western tropical North Atlantic. Our results support the idea that the diatom host provides the endosymbiotic cyanobacterium with organic carbon to fuel N2 fixation. This knowledge is key to understanding the physiology of the globally significant H. hauckii–R. euintracellularis symbiosis.
|
|
19. |
- Norevik, Gabriel, et al.
(författare)
-
Extremely low daylight sea-crossing flights of a nocturnal migrant
- 2023
-
Ingår i: PNAS Nexus. - 2752-6542. ; 2:7
-
Tidskriftsartikel (refereegranskat)abstract
- Understanding the trade-off between energy expenditure of carrying large fuel loads and the risk of fuel depletion is imperative to understand the evolution of flight strategies during long-distance animal migration. Global flyways regularly involve sea crossings that may impose flight prolongations on migrating land-birds and thereby reduce their energy reserves and survival prospects. We studied route choice, flight behavior, and fuel store dynamics of nocturnally migrating European nightjars (Caprimulgus europaeus) crossing water barriers. We show that barrier size and groundspeed of the birds influence the prospects of extended daylight flights, but also that waters possible to cross within a night regularly result in diurnal flight events. The nightjars systematically responded to daylight flights by descending to about a wingspan's altitude above the sea surface while switching to an energy-efficient flap-glide flight style. By operating within the surface-air boundary layer, the nightjars could fly in ground effect, exploit local updraft and pressure variations, and thereby substantially reduce flight costs as indicated by their increased proportion of cheap glides. We propose that surface-skimming flights, as illustrated in the nightjar, provide an energy-efficient transport mode and that this novel finding asks for a reconsideration of our understanding of flight strategies when land-birds migrate across seas.
|
|
20. |
- Pavlović, T, et al.
(författare)
-
Predicting attitudinal and behavioral responses to COVID-19 pandemic using machine learning
- 2022
-
Ingår i: PNAS nexus. - : Oxford University Press (OUP). - 2752-6542. ; 1:3, s. pgac093-
-
Tidskriftsartikel (refereegranskat)abstract
- At the beginning of 2020, COVID-19 became a global problem. Despite all the efforts to emphasize the relevance of preventive measures, not everyone adhered to them. Thus, learning more about the characteristics determining attitudinal and behavioral responses to the pandemic is crucial to improving future interventions. In this study, we applied machine learning on the multi-national data collected by the International Collaboration on the Social and Moral Psychology of COVID-19 (N = 51,404) to test the predictive efficacy of constructs from social, moral, cognitive, and personality psychology, as well as socio-demographic factors, in the attitudinal and behavioral responses to the pandemic. The results point to several valuable insights. Internalized moral identity provided the most consistent predictive contribution—individuals perceiving moral traits as central to their self-concept reported higher adherence to preventive measures. Similar was found for morality as cooperation, symbolized moral identity, self-control, open-mindedness, collective narcissism, while the inverse relationship was evident for the endorsement of conspiracy theories. However, we also found a non-negligible variability in the explained variance and predictive contributions with respect to macro-level factors such as the pandemic stage or cultural region. Overall, the results underscore the importance of morality-related and contextual factors in understanding adherence to public health recommendations during the pandemic.
|
|
21. |
- Ramos, Jairo, et al.
(författare)
-
Structured reflection increases intentions to reduce other people's health risks during COVID-19
- 2022
-
Ingår i: PNAS nexus. - : Oxford University Press. - 2752-6542. ; 1:5
-
Tidskriftsartikel (refereegranskat)abstract
- People believe they should consider how their behavior might negatively impact other people, Yet their behavior often increases others' health risks. This creates challenges for managing public health crises like the COVID-19 pandemic. We examined a procedure wherein people reflect on their personal criteria regarding how their behavior impacts others' health risks. We expected structured reflection to increase people's intentions and decisions to reduce others' health risks. Structured reflection increases attention to others' health risks and the correspondence between people's personal criteria and behavioral intentions. In four experiments during COVID-19, people (N = 12,995) reported their personal criteria about how much specific attributes, including the impact on others' health risks, should influence their behavior. Compared with control conditions, people who engaged in structured reflection reported greater intentions to reduce business capacity (experiment 1) and avoid large social gatherings (experiments 2 and 3). They also donated more to provide vaccines to refugees (experiment 4). These effects emerged across seven countries that varied in collectivism and COVID-19 case rates (experiments 1 and 2). Structured reflection was distinct from instructions to carefully deliberate (experiment 3). Structured reflection increased the correlation between personal criteria and behavioral intentions (experiments 1 and 3). And structured reflection increased donations more among people who scored lower in cognitive reflection compared with those who scored higher in cognitive reflection (experiment 4). These findings suggest that structured reflection can effectively increase behaviors to reduce public health risks.
|
|
22. |
- Saluri, Mihkel, et al.
(författare)
-
A “grappling hook” interaction connects self-assembly and chaperone activity of Nucleophosmin 1
- 2023
-
Ingår i: pnas nexus. - : Oxford University Press (OUP). - 2752-6542. ; 2:2
-
Tidskriftsartikel (refereegranskat)abstract
- How the self-assembly of partially disordered proteins generates functional compartments in the cytoplasm and particularly in the nucleus is poorly understood. Nucleophosmin 1 (NPM1) is an abundant nucleolar protein that forms large oligomers and undergoes liquid-liquid phase separation by binding RNA or ribosomal proteins. It provides the scaffold for ribosome assembly but also prevents protein aggregation as part of the cellular stress response. Here, we use aggregation assays and native mass spectrometry (MS) to examine the relationship between the self-assembly and chaperone activity of NPM1. We find that oligomerization of full-length NPM1 modulates its ability to retard amyloid formation in vitro. Machine learning-based structure prediction and cryo-electron microscopy reveal fuzzy interactions between the acidic disordered region and the C-terminal nucleotide-binding domain, which cross-link NPM1 pentamers into partially disordered oligomers. The addition of basic peptides results in a tighter association within the oligomers, reducing their capacity to prevent amyloid formation. Together, our findings show that NPM1 uses a grappling hook mechanism to form a network-like structure that traps aggregation-prone proteins. Nucleolar proteins and RNAs simultaneously modulate the association strength and chaperone activity, suggesting a mechanism by which nucleolar composition regulates the chaperone activity of NPM1.
|
|
23. |
- Triki, Zegni, 1984-, et al.
(författare)
-
Experimental expansion of relative telencephalon size improves the main executive function abilities in guppy
- 2023
-
Ingår i: PNAS Nexus. - 2752-6542. ; 2:6
-
Tidskriftsartikel (refereegranskat)abstract
- Executive functions are a set of cognitive control processes required for optimizing goal-directed behavior. Despite more than two centuries of research on executive functions, mostly in humans and nonhuman primates, there is still a knowledge gap in what constitutes the mechanistic basis of evolutionary variation in executive function abilities. Here, we show experimentally that size changes in a forebrain structure (i.e. telencephalon) underlie individual variation in executive function capacities in a fish. For this, we used male guppies (Poecilia reticulata) issued from artificial selection lines with substantial differences in telencephalon size relative to the rest of the brain. We tested fish from the up- and down-selected lines not only in three tasks for the main core executive functions: cognitive flexibility, inhibitory control, and working memory, but also in a basic conditioning test that does not require executive functions. Individuals with relatively larger telencephalons outperformed individuals with smaller telencephalons in all three executive function assays but not in the conditioning assay. Based on our findings, we propose that the telencephalon is the executive brain in teleost fish. Together, it suggests that selective enlargement of key brain structures with distinct functions, like the fish telencephalon, is a potent evolutionary pathway toward evolutionary enhancement of advanced cognitive abilities in vertebrates.
|
|
24. |
- Wang,, L., et al.
(författare)
-
Domino effect of a natural cascade alpine lake system on the Third Pole
- 2022
-
Ingår i: PNAS Nexus. - : Oxford University Press (OUP). - 2752-6542. ; 1:3
-
Tidskriftsartikel (refereegranskat)abstract
- Third Pole natural cascade alpine lakes (NCALs) are exceptionally sensitive to climate change, yet the underlying cryosphere-hydrological processes and associated societal impacts are largely unknown. Here, with a state-of-the-art cryosphere-hydrology-lake-dam model, we quantified the notable high-mountain Hoh-Xil NCALs basin (including Lakes Zonag, Kusai, Hedin Noel, and Yanhu, from upstream to downstream) formed by the Lake Zonag outburst in September 2011. We demonstrate that long-term increased precipitation and accelerated ice and snow melting as well as short-term heavy precipitation and earthquake events were responsible for the Lake Zonag outburst; while the permafrost degradation only had a marginal impact on the lake inflows but was crucial to lakeshore stability. The quadrupling of the Lake Yanhu area since 2012 was due to the tripling of inflows (from 0.25 to 0.76 km3/year for 1999 to 2010 and 2012 to 2018, respectively). Prediction of the NCALs changes suggests a high risk of the downstream Qinghai–Tibet Railway, necessitating timely adaptions/mitigations.
|
|
25. |
- Yu, Kailiang, et al.
(författare)
-
Forest demography and biomass accumulation rates are associated with transient mean tree size vs. density scaling relations
- 2024
-
Ingår i: PNAS Nexus. - 2752-6542. ; 3:2
-
Tidskriftsartikel (refereegranskat)abstract
- Linking individual and stand-level dynamics during forest development reveals a scaling relationship between mean tree size and tree density in forest stands, which integrates forest structure and function. However, the nature of this so-called scaling law and its variation across broad spatial scales remain unquantified, and its linkage with forest demographic processes and carbon dynamics remains elusive. In this study, we develop a theoretical framework and compile a broad-scale dataset of long-term sample forest stands (n = 1,433) from largely undisturbed forests to examine the association of temporal mean tree size vs. density scaling trajectories (slopes) with biomass accumulation rates and the sensitivity of scaling slopes to environmental and demographic drivers. The results empirically demonstrate a large variation of scaling slopes, ranging from −4 to −0.2, across forest stands in tropical, temperate, and boreal forest biomes. Steeper scaling slopes are associated with higher rates of biomass accumulation, resulting from a lower offset of forest growth by biomass loss from mortality. In North America, scaling slopes are positively correlated with forest stand age and rainfall seasonality, thus suggesting a higher rate of biomass accumulation in younger forests with lower rainfall seasonality. These results demonstrate the strong association of the transient mean tree size vs. density scaling trajectories with forest demography and biomass accumulation rates, thus highlighting the potential of leveraging forest structure properties to predict forest demography, carbon fluxes, and dynamics at broad spatial scales.
|
|