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Climate change and deoxygenation are affecting fish stocks on a global scale, but disentangling the impacts of these stressors from the effects of overfishing is a challenge. This study was conducted to distinguish between climate change and mismanagement as possible causes for the drastic decline in spawning stock size and reproductive success in cod (Gadus morhua) and herring (Clupea harengus) in the Western Baltic Sea, when compared with the good or satisfactory status and reproductive success of the other commercial species in the area. Available data on water temperature, wind speed, and plankton bloom during the spawning season did not reveal conclusive correlations between years with good and bad reproductive success of cod or herring. Notably, the other commercial species in the area have very similar life history traits suggesting similar resilience against stress caused by climate change or fishing. The study concludes that severe, sustained overfishing plus inappropriate size selectivity of the main fishing gears have caused the decline in spawning stock biomass of cod and herring to levels that are known to have a high probability of impaired reproductive success. It is pointed out that allowed catches were regulated by management and adhered to by the fishers, meaning that unregulated fishing did not occur. Thus, mismanagement (quotas that were too high and gears that selected too small sizes) and not climate change appears to be the primary cause of the bad status of cod and herring in the Western Baltic Sea.

The fishery for Northern Atlantic cod (Gadus morhua) off Newfoundland and Labrador, Eastern Canada, presents the most spectacular case of an exploited stock crashed in a few decades by an industrial bottom trawl fishery under a seemingly sophisticated management regime after half a millennium of sustainable fishing. The fishery, which had generated annual catches of 100000 to 200000 tonnes from the beginning of the 16th century to the 1950s, peaked in 1968 at 810000 tonnes, followed by a devastating collapse and closure 24 years later. Since then, stock recovery may have been hindered by premature openings, with vessels targeting the remains of the cod population. Previous research paid little attention towards using multicentury time series to inform sustainable catches and recovery plans. Here, we show that a simple stock assessment model can be used to model the cod population trajectory for the entire period from 1508 to 2019 for which catch estimates are available. The model suggests that if fishing effort and mortality had been stabilized in the 1980s, precautionary annual yields of about 200000 tonnes could have been sustained. Our analysis demonstrates the value of incorporating prior knowledge to counteract shifting baseline effects on reference points and contemporary perceptions of historical stock status.

Acknowledgements: Acknowledgements: We thank D. H. Mann for his detailed and constructive comments; and T. Ager, J. Austin, T. B. Brand, A. Cooper, S. Funder, M. T. P. Gilbert, T. Jørgensen, N. J. Korsgaard, S. Liu, M. Meldgaard, P. V. S. Olsen, M. L. Siggaard-Andersen, J. Stenderup, S. A. Woodroffe and staff at the GeoGenetics Sequencing Core and National Park Service-Western Arctic National Parklands for help and support. E.W. and D.J.M. thank the staff at St. John’s College, Cambridge, for providing a stimulating environment for scientific discussion of the project. E.W. thanks Illumina for collaboration. The Lundbeck Foundation GeoGenetics Centre is supported by the Carlsberg Foundation (CF18-0024), the Lundbeck Foundation (R302-2018-2155), the Novo Nordisk Foundation (NNF18SA0035006), the Wellcome Trust (UNS69906) and GRF EXC CRS Chair (44113220)—Cluster of Excellence. The PhyloNorway plant genome database is part of the Norwegian Barcode of Life Network (https://www.norbol.org) funded by the Research Council of Norway (226134/F50), the Norwegian Biodiversity Information Centre (14-14, 70184209) and The Arctic University Museum of Norway. Metabarcoding sequencing was funded by the Central Public-Interest Scientific Institution Basal Research Fund, CAFS (2017B001 and 2020A001). B.D.S. is supported by the Wellcome Trust programme in Mathematical Genomics and Medicine (WT220023); F.R. by a Villum Fonden Young Investigator award (no. 00025300); D.J.M. by the Quest Archaeological Research Fund; P.M. by the Swedish Research Council (VR); R.D. by the Wellcome Trust (WT207492); and A.R. by a Marie Skłodowska-Curie Actions Individual Fellowship (MSCA-IF, 703542) and the Research Council of Norway (KLIMAFORSK, 294929). L.O. has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (no. 681605); I.G.A. and Y.L. from the ERC under the European Union’s Horizon 2020 research and innovation programme (no. 819192). J.I.S. and J.M. are supported by the Research Council of Norway. P.B.H. and N.R.E. acknowledge NERC funding (grant NE/P015093/1). D.W.B. was supported by a Marie Skłodowska-Curie Actions Incoming International Fellowship (MCIIF-40974). T.S.K. is funded by a Carlsberg Foundation Young Researcher Fellowship (CF19-0712)., During the last glacial-interglacial cycle, Arctic biotas experienced substantial climatic changes, yet the nature, extent and rate of their responses are not fully understood1-8. Here we report a large-scale environmental DNA metagenomic study of ancient plant and mammal communities, analysing 535 permafrost and lake sediment samples from across the Arctic spanning the past 50,000 years. Furthermore, we present 1,541 contemporary plant genome assemblies that were generated as reference sequences. Our study provides several insights into the long-term dynamics of the Arctic biota at the circumpolar and regional scales. Our key findings include: (1) a relatively homogeneous steppe-tundra flora dominated the Arctic during the Last Glacial Maximum, followed by regional divergence of vegetation during the Holocene epoch; (2) certain grazing animals consistently co-occurred in space and time; (3) humans appear to have been a minor factor in driving animal distributions; (4) higher effective precipitation, as well as an increase in the proportion of wetland plants, show negative effects on animal diversity; (5) the persistence of the steppe-tundra vegetation in northern Siberia enabled the late survival of several now-extinct megafauna species, including the woolly mammoth until 3.9 ± 0.2 thousand years ago (ka) and the woolly rhinoceros until 9.8 ± 0.2 ka; and (6) phylogenetic analysis of mammoth environmental DNA reveals a previously unsampled mitochondrial lineage. Our findings highlight the power of ancient environmental metagenomics analyses to advance understanding of population histories and long-term ecological dynamics.

We report the true nature of active catalysts in the polymerization of 1-octene catalyzed by the racemic hafnium-pyridyl amido cation (I). Chromophore quench-labeling (CQL) studies reveal that only...

The kinetics of higher alcohol synthesis was investigated using a hydrotalcite-derived Co-Cu-based catalyst aiming at a deeper understanding of the complex reaction network. At steady state similar chain growth probabilities of about 0.4 according to the Anderson-Schulz-Flory distribution were observed for alcohols, hydrocarbons and olefins indicating common intermediates. Alkanes were found to be formed consecutively from primarily formed olefins. The observed decrease of the selectivities to alcohols with increasing CO conversion at higher temperatures and higher residence times is ascribed to an increased availability of adsorbed atomic hydrogen, which decreases the saturated coverage of CO-derived CxHyOz species favoring hydrocarbon formation. Correspondingly, reaction orders of 0 and 0.8 for CO and H2, respectively, were derived based on a power-law approach including an apparent activation energy of 140 kJ mol−1. A reaction network based on the CO insertion factor was established, in which the competing reactions β-hydrogen elimination, chain growth and CO insertion proceed from common adsorbed CxHy intermediates. Selective higher alcohol formation was favored at low temperatures and short residence times, high pressures and a moderate H2:CO ratio of 1 requiring a compromise between conversion and selectivity.

Dung beetles are frequently used to assess tropical biodiversity patterns and recovery in human‐modified forests. We conducted a comprehensive dung beetle survey (coprophagous and necrophagous communities) within five habitat types, across a land‐use gradient, in the ecologically biodiverse Osa Peninsula, located in Costa Rica's south Pacific. In addition to assessing species richness, abundance, and biomass, we also assessed community level traits and species‐specific responses using a generalised joint attribute modelling approach. We found that under favourable conditions (40–50 years of regeneration, close proximity to contiguous old‐growth forest and control of poaching), secondary rainforest recovered similar levels of species richness, and key traits of old‐growth forest dung beetle communities. However, at the community‐level, dung beetle abundance, richness, biomass, and diversity varied between habitat types of different anthropogenic disturbance and land‐use. Generally, the carrion beetle community did not recover as well as the dung beetle community and the abundance of dung beetles was a third lower in naturally regenerating secondary forest compared with old growth. Regenerating secondary growth and plantation forests showed community compositions similar to old growth forests, while open and fragmented habitats had degraded and impoverished levels of dung beetle biodiversity. Overall, the levels of dung‐beetle biodiversity detected are encouraging for naturally regenerating secondary forest, suggesting a high potential value of these areas to buffer the pressure of deforestation and habitat alteration on remaining old‐growth tropical forests.

Foliar fertilization is a potential strategy to supplement phosphorus (P) requirements when conditions permit. In 2016 and 2017, canola, wheat, and pea were grown in a randomized complete block design trial near Pilger, SK, Canada. Each crop received a total P application of 20 kg P2O5 ha−1, with varying proportions of the P applied as seed-placed monoammonium phosphate (MAP) supplemented with foliar KH2PO4 (0%, 25%, 50%, and 100%) applied prior to anthesis. Under field conditions, yield response decreased as the proportion applied as seed-placed MAP decreased. The 100% foliar-applied P treatment in canola was able to maintain significantly higher yield than the unfertilized control in the absence of seed-placed MAP, indicating some uptake and response. Of the crops evaluated, canola was most responsive to P fertilization. Phytate content ranged from 68% to over 90% of total seed P, with the highest proportions found in wheat grain. Foliar P application had limited effect on phytate and grain iron content, but there appeared to be an inverse relationship between seed-placed MAP and grain zinc concentration that was less evident when P was applied in foliar form. In this study, foliar P application was unable to substitute for seed-placed MAP and overall had a marginal effect on grain yield and P uptake as well as seed nutritional value.

Most plant diversity in temperate deciduous forests is found in the ground layer, but nearly all studies comparing plant community assembly using taxonomic, trait, and phylogenetic diversity indices are limited to woody plants. To examine the relationship between short-term ground-layer plant community assembly and disturbance severity, we leveraged a silvicultural experiment that applied a combination of harvest and site preparation treatments in a northern hardwood forest in Michigan, USA. We predicted that after two growing seasons, plant communities would be less sensitive to harvest treatments when compared with site preparation treatments that disturb the rhizosphere and modify rooting substrate. We also predicted that an increase in taxonomic diversity would accompany a decline in trait diversity and phylogenetic diversity. Instead, plant species composition responded similarly to harvest treatment and site preparation treatment. However, our measure of disturbance severity was positively correlated with both trait diversity and taxonomic diversity but negatively correlated with phylogenetic diversity, indicating that increasingly diverse traits and taxonomies along this disturbance severity gradient were comprised of more phylogenetically simple plant communities. Informed management decisions should therefore consider the underlying value of each diversity measure, as taxonomic diversity alone may not be the best metric for assessing plant community assembly.

Sedimentary ancient DNA (sedaDNA) has been established as a viable biomolecular proxy for tracking taxon presence through time in a local environment, even in the total absence of surviving tissues. SedaDNA is thought to survive through mineral binding, facilitating long-term biomolecular preservation, but also challenging DNA isolation. Two common limitations in sedaDNA extraction are the carryover of other substances that inhibit enzymatic reactions, and the loss of authentic sedaDNA when attempting to reduce inhibitor co-elution. Here, we present a sedaDNA extraction procedure paired with targeted enrichment intended to maximize DNA recovery. Our procedure exhibits a 7.7–19.3x increase in on-target plant and animal sedaDNA compared to a commercial soil extraction kit, and a 1.2–59.9x increase compared to a metabarcoding approach. To illustrate the effectiveness of our cold spin extraction and PalaeoChip capture enrichment approach, we present results for the diachronic presence of plants and animals from Yukon permafrost samples dating to the Pleistocene-Holocene transition, and discuss new potential evidence for the late survival (~9700 years ago) of mammoth (Mammuthus sp.) and horse (Equus sp.) in the Klondike region of Yukon, Canada. This enrichment approach translates to a more taxonomically diverse dataset and improved on-target sequencing.

Terrain visibility graphs are a well-known graph class in computational geometry. They are closely related to polygon visibility graphs, but a precise graph-theoretical characterization is still unknown. Over the last decade, terrain visibility graphs attracted considerable attention in the context of time series analysis (there called time series visibility graphs) with various practical applications in areas such as physics, geography, and medical sciences. Computing shortest paths in visibility graphs is a common task, for example, in line-of-sight communication. For time series analysis, graph characteristics involving shortest paths lengths (such as centrality measures) have proven useful. In this paper, we devise a fast output-sensitive shortest path algorithm on a superclass of terrain visibility graphs called terrain-like graphs (including all induced subgraphs of terrain visibility graphs). Our algorithm runs in $$O(d^*\log \varDelta )$$ O ( d ∗ log Δ ) time, where $$d^*$$ d ∗ is the length (that is, the number of edges) of the shortest path and $$\varDelta $$ Δ is the maximum vertex degree. Alternatively, with an $$O(n^2)$$ O ( n 2 ) -time preprocessing our algorithm runs in $$O(d^*)$$ O ( d ∗ ) time.

Bimetallic Co-Cu catalysts are widely applied in higher alcohol synthesis (HAS), but the formation of the final active structure has not yet been fully clarified, especially for Co-rich catalysts. We investigated the structural evolution of a Co-Cu catalyst (Co:Cu = 2) from the hydrotalcite precursor containing additional Al3+ and Zn2+ to the final active state after 80 h under reaction conditions at 280 °C and 60 bar. The reconstruction of the bimetallic Co-Cu nanoparticles obtained by H2 reduction was induced by the feed gas consisting of an equimolar H2 and CO syngas mixture resulting in fast phase separation and sintering of metallic Cu0 and Co0 in the first 2 h time on stream (TOS) and a continuous carbidization of Co0 forming Co2C and its sintering until steady state was reached after 40 h TOS. An intergrowth of metallic Cu0 nanoparticles with Co2C nanoparticles was observed to occur under reaction conditions. The high selectivity to oxygenates amounting to 41% compared with 29% to hydrocarbons is ascribed to the multi-functional Co2C/Cu0 interface enabling dissociative CO adsorption, hydrogenation and CO insertion. The formation of hydrogenated carbon species (CxHy) originating from dissociative CO chemisorption is assumed to be favored by hydrogen spillover from Cu0 to Co2C. The adsorption sites for molecular CO provided by both Cu0 and Co2C facilitate its insertion into the CxHy intermediates thus leading to a higher selectivity to alcohols following the Anderson-Schulz-Flory distribution.

A consolidated bioprocessing (CBP) approach utilizing a synergistic co-culture of three lignocellulolytic bacteria (Clostridium thermocellum, C. stercorarium, and Thermoanaerobacter thermohydrosulfuricus) was compared with the monoculture controls using a variety of different lignocellulosic substrates. In addition to increasing the average ethanol:acetate:lactate ratio from 49:45:6 in the C. thermocellum monoculture to 66:26:7 in the tri-culture, the amount of total polysaccharides utilized in the tri-culture relative to the monocultures was increased in all untreated and pretreated substrates tested, with up to 3-fold increases observed. Under relatively low carbon loads of 2 g/L, the highest ethanol titre achieved was 0.298 g/L, corresponding to a yield of 0.149 g ethanol/g substrate. The co-culture was then used to screen the digestibility of different cattail (Typha spp.) species harvested in different seasons as well as wheat straw samples from different cultivars that vary in their resistance to lodging. Cattail plants that harvested in July contained less cellulose and lignin and were up to 80% more digestible than those harvested in September. Although moderate differences in wheat straw digestibility were observed, this variation did not significantly correlate with differences in lodging resistance or cellulose, hemicellulose, and lignin contents. Our study suggests the importance of screening feedstocks using CBP approaches in order to determine the attributes that affect digestibility with CBP.

Sustainably managed wild fisheries support food and nutritional security, livelihoods, and cultures (1). Harmful fisheries subsidies—government payments that incentivize overcapacity and lead to overfishing—undermine these benefits yet are increasing globally (2). World Trade Organization (WTO) members have a unique opportunity at their ministerial meeting in November to reach an agreement that eliminates harmful subsidies (3). We—a group of scientists spanning 46 countries and 6 continents—urge the WTO to make this commitment...

We introduce a generalized finite difference method for solving a large range of fully nonlinear elliptic partial differential equations in three dimensions. Methods are based on Cartesian grids, augmented by additional points carefully placed along the boundary at high resolution. We introduce and analyze a least-squares approach to building consistent, monotone approximations of second directional derivatives on these grids. We then show how to efficiently approximate functions of the eigenvalues of the Hessian through a multi-level discretization of orthogonal coordinate frames in $\mathbb{R}^3$. The resulting schemes are monotone and fit within many recently developed convergence frameworks for fully nonlinear elliptic equations including non-classical Dirichlet problems that admit discontinuous solutions, Monge-Amp\`ere type equations in optimal transport, and eigenvalue problems involving nonlinear elliptic operators. Computational examples demonstrate the success of this method on a wide range of challenging examples., Comment: 28 pages, 11 figures, submitted to the Journal of Scientific Computing

Ice-rich permafrost in the circum-Arctic and sub-Arctic (hereafter pan-Arctic), such as late Pleistocene Yedoma, are especially prone to degradation due to climate change or human activity. When Yedoma deposits thaw, large amounts of frozen organic matter and biogeochemically relevant elements return into current biogeochemical cycles. This mobilization of elements has local and global implications: increased thaw in thermokarst or thermal erosion settings enhances greenhouse gas fluxes from permafrost regions. In addition, this ice-rich ground is of special concern for infrastructure stability as the terrain surface settles along with thawing. Finally, understanding the distribution of the Yedoma domain area provides a window into the Pleistocene past and allows reconstruction of Ice Age environmental conditions and past mammoth-steppe landscapes. Therefore, a detailed assessment of the current pan-Arctic Yedoma coverage is of importance to estimate its potential contribution to permafrost-climate feedbacks, assess infrastructure vulnerabilities, and understand past environmental and permafrost dynamics. Building on previous mapping efforts, the objective of this paper is to compile the first digital pan-Arctic Yedoma map and spatial database of Yedoma coverage. Therefore, we 1) synthesized, analyzed, and digitized geological and stratigraphical maps allowing identification of Yedoma occurrence at all available scales, and 2) compiled field data and expert knowledge for creating Yedoma map confidence classes. We used GIS-techniques to vectorize maps and harmonize site information based on expert knowledge. We included a range of attributes for Yedoma areas based on lithological and stratigraphic information from the source maps and assigned three different confidence levels of the presence of Yedoma (confirmed, likely, or uncertain). Using a spatial buffer of 20 km around mapped Yedoma occurrences, we derived an extent of the Yedoma domain. Our result is a vector-based map of the current pan-Arctic Yedoma domain that covers approximately 2,587,000 km2, whereas Yedoma deposits are found within 480,000 km2of this region. We estimate that 35% of the total Yedoma area today is located in the tundra zone, and 65% in the taiga zone. With this Yedoma mapping, we outlined the substantial spatial extent of late Pleistocene Yedoma deposits and created a unique pan-Arctic dataset including confidence estimates.

The maximum sustainable yield (MSY) concept is widely considered to be outdated and misleading. In response, fisheries scientists have developed models that often diverge radically from the first operational version of the concept. We show that the original MSY concept was deeply rooted in ecology and that going back to that version would be beneficial for fisheries, not least because the various substitutes have not served us well.

The relative rates of arylation of primary alkylamines with different Pd-NHC catalysts have been measured, as have the relative rates of arylation of the secondary aniline product in an attempt to understand the key ligand design features necessary to have high selectivity for the monoarylated amine product. As the substituents on the N-aryl ring of the NHC increase in size, selectivity for monoarylation increases and this is further enhanced by chlorinating the back of the NHC ring. Computations have been performed on the catalytic cycle of this transformation in order to understand the selectivity obtained with the different catalysts.

When an invasive alien ‘weed’ emerges in a previously uninhabited landscape, land managers must respond quickly to facilitate effective eradication or containment, and minimize long-term negative impacts. However, on-ground management decisions are often made under time, knowledge and capacity constraints. Spatially explicit tools for assessing invasion risk rapidly and under uncertainty would help land managers to better target interventions. We developed a generic methodology that integrates (a) interactions between ecological risk factors and invasion processes affecting both the potential suitability for population growth and the actual susceptibility to propagule introduction from source populations with (b) spatially explicit data in (c) a probabilistic Bayesian network modelling framework. Our methods focused on the operational needs of land mangers responding to weed incursions, streamlining data and knowledge collection, simplifying model calibration, and facilitating adoption via a collection of user-friendly web apps called riskmapr. We tested the generality of our methodology on two contrasting weeds (the rainforest tree Cecropia spp. and the cactus Cylindropuntia rosea) that are targeted for containment and local eradication in Queensland, Australia. Case study models were calibrated from published knowledge about abiotic and biotic factors affecting suitability for, and susceptibility to, weed invasion. Validation of annual risk maps against weed detections in subsequent years showed that models accurately predicted the field-observed progression of each invasion to date. We developed a rapid spatial risk modelling methodology that is theoretically comprehensive and practically simple. Our streamlined methods and open access implementation using riskmapr facilitate adoption by land managers. Models and risk maps can be used to target interventions or improve spatially explicit understanding of the risk factors and processes driving early weed invasions.

Harvest residues are an abundant by-product of commodity management in working forests, with significant potential as feedstock for bioenergy and advanced biomaterials. While contemporary experimental research programs seek to determine the short-term impacts of intensive residue removal on soil conditions and site productivity, rotation-length implications in operational settings remain speculative. Nonetheless, it is generally recognized that the effects of residue recovery are cover type and site dependent, and that production lands will be the primary source of increased utilization. We leveraged historical records across a 40-year chronosequence of 46 individual Populus spp. stands in upper Michigan harvested with Whole-tree harvest (WTH) and Stem-only harvest (STH) to observe and evaluate these practices on aboveground productivity and soil chemical properties. Stands were located across 4 contrasting soil types that are typical of site productivity and textural classes within the Great Lakes region. Results indicate a 36% reduction of residues in WTH treatments at 15.04 Mg ha−1 compared with 23.43 Mg ha−1 at stand establishment, yet residue levels in both treatments exceeded regional biomass retention guidelines, and differences were negligible by 16 years. The data further suggest that stand productivity is unaffected by harvest treatment. Soil C, N and macronutrients exhibited high variability across soil types, with mixed responses to treatments. These results highlight the significant amounts of residues remaining on site following operational WTH and that these practices do not appear to alter aboveground productivity of the Populus cover type across a range of soil types.

The increased use of radiocarbon analyses for archeological, paleontological, and paleoclimate research has created a demand for robust and well characterized procedural blanks. Currently, blanks are distributed ad hoc throughout the radiocarbon community in limited quantities and are depleted quickly by high throughput labs. This forces AMS facilities to regularly seek out suitable blanks from other facilities, and the switch to different blank material inhibits assessment of long term procedural blank performance. An excellent source for well-preserved radiocarbon “dead” organic material is the permafrost-rich region of unglaciated Yukon and Alaska. Extensive placer mining operations and river bluffs expose Middle Pleistocene sediments that regularly yield pristine organic material. Here, we present an assessment of laboratory precision and overall measure of performance of two processing blanks from the region. The AVR-07-PAL-37 wood and Hollis Mammoth pelvis bone collected from Alaska and Yukon, respectively. Both are independently dated to the Middle Pleistocene and have been verified by 14C-AMS to be radiocarbon “dead”, with mean FmC of 0.0054 ± 0.0002 (n = 714) and 0.0031 ± 0.0002, (n = 219), respectively. Preliminary use at several AMS and stable isotope facilities in the U.S.A., Canada, United Kingdom, and China confirms that AVR-07-PAL-37 and Hollis Mammoth are suitable blanks for radiocarbon analyses. Both materials are available for wide distribution to other interested AMS labs.

Genetic estimation of population sizes has been critical for monitoring cryptic and rare species; however, population estimates do not inherently reveal the permanence or stability of the population under study. Thus, it is important to monitor not only the number of individuals in a population, but also how they are associated in groups and how those groups are distributed across the landscape. Adding to the challenge of obtaining such information with high precision for endangered and elusive species is the need for long-term collection of such data. In this study we compare sampling approaches and genotype non-invasive genetic samples to estimate the number and distribution of wild western lowland gorillas occupying a ˘005Ctextasciitildeþinspace100 km2 area in Loango National Park, Gabon, for the periods 2005–2007 and 2014–2017. Based on the number of genotyped individuals we inferred a minimum of 83 gorillas during the first and 81 gorillas during the second study period. We also obtained similar capture–recapture population size estimates for the two periods despite variance in social dynamics like group formations, group dissolutions and individual dispersal. We furthermore found area fidelity for two groups that were sampled for 10–12 years, despite variation in group membership. Our results revealed how individual movements link groups in a `network' and show that western lowland gorilla populations can show a high degree of temporal and geographic stability concurrent with substantial social dynamics.

Invasive alien plant species threaten agriculture and biodiversity globally and require ongoing management to minimise impacts. However, the large number of invasive species means that a risk-based approach to prioritisation is needed, taking into account the spatial scale of management decisions and myriad of available information. Here, we developed a risk-based inventory of invasive plants in Queensland, Australia, using both current species distribution/abundance and the severity of their impacts. Our assessment followed a comprehensive data collection process including a scoping of local government pest management plans, herbarium records, the published literature and structured elicitation of expert knowledge during a series of regional stakeholder workshops. From ~300 plant species that were identified as established and/or emerging invaders in the State, only one-third were considered by practitioners to pose significant risks across regions to be considered management priorities. We aggregated regional species lists into a statewide priority list and analysed the data set (107 species) for historical, geographical, floristic and ecological patterns. Regions on the mainland eastern seaboard of the State share similar invasive plant communities, suggesting that these regions may form a single management unit, unlike the western/inland and the extreme far north (Torres Strait Islands) regions, which share fewer invasive plant species. Positive correlations were detected between invasiveness and time since introduction for some but not all plant life forms. Stakeholders identified research and management priorities for the invasive plant list, including biological control options, public awareness/education, effective herbicide use, ecology/taxonomy and risk analysis. In the course of the exercise, a statewide invasive plant priority list of high-, medium- and low-impact scores for policy, research and management was compiled. Finally, our approach to invasive plant species prioritisation highlighted that planning and policy documents are not necessarily reflected at the grass-root level in terms of species identity and management priorities.

Tropical areas are facing a bushmeat crisis involving the systematic over-exploitation of large-bodied mammals for both subsistence and commercial purposes. We hypothesize that because hunting generally originates from villages, it will create “halos of defaunation” where abundances of large mammals increase with distance away from villages. Whilst such patterns have been well characterized at the landscape scale, examining how defaunation halos vary between different villages has received considerably less attention. Forests immediately surrounding villages are of considerable importance to the people residing within them and the factors hypothesized to influence local defaunation halos (e.g. village size, hunting practices and access to local markets) may affect local livelihoods and the ecological integrity of nearby forests. To address this, we adopted a participatory approach to establish and monitor sixty transects across ten village-distance gradients (1-8 km) in Gabon. Trained paraecologists, recruited from local villages, walked each transect twice monthly to determine the encounter rates of medium and large mammals across the village distance gradient and monitored village-level bushmeat availability. We found that overall rates of mammal observation and estimated species richness were constant across the village-distance gradient, however the total number of individuals encountered and bushmeat biomass were lower close to villages – consistent with local depletion of wildlife. These general trends were underpinned by depleted mammal species diversity with increasing proximity to villages and a marked shift in mammal community composition: small, non-hunted species were encountered most frequently near villages, whereas large, hunted species were encountered most frequently away from villages. We found some evidence for inter-village variation in the strength and depth of defaunation halos, which may be driven in part by the village-level hunting intensity. Several of the key parameters identified in landscape-scale bushmeat studies did not detectably influence village-level defaunation (e.g. road or market distance). Despite the prevalence of bushmeat hunting in the region, the conservation value of forests immediately surrounding villages was demonstrated through the detection of large-bodied species of conservation concern (e.g. chimpanzee and gorilla) at a high proportion of survey locations. The compositional shifts in mammal communities detailed here will ultimately lead to the altered composition and diversity of forests around villages, with potential implications for human livelihoods, health and transmission of zoonotic disease. This research also demonstrates the effectiveness of engaging paraecologists to answer focused ecological questions - the first step in facilitating effective natural resource management by local communities.

SummaryThe Maleo Macrocephalon Maleo is a megapode bird endemic to Sulawesi, Indonesia, that lays large eggs at communal nesting grounds in naturally-heated sands or soils. It is classified as ‘Endangered’ and many populations have been extirpated due to overexploitation of eggs and loss of connectivity between forest and nesting grounds. The distribution and status of nesting grounds across Northern and Central Sulawesi are relatively well-established, but almost nothing is known about potential Maleo populations of South-east Sulawesi. In this study we used previously established methods to formally assess the status of three Maleo nesting grounds in Buton, South-east Sulawesi, and interviewed egg collectors at these three sites to determine the trends of populations and threats over time. All nesting grounds were severely threatened and can be expected to be abandoned in the near future due to extensive harvest of eggs and deforestation. Eggs were collected both for the wildlife trade (intensively harvested and sold as luxury items to people from distant cities) and local use (opportunistically harvested and both eaten and sold locally). All egg collectors remarked on an increase in illegal logging around nesting grounds over the previous decade. Though the Maleo’s current situation is dire, previous case studies show that collaborative grassroots initiatives supported by government and NGOs can protect nesting grounds and reverse population declines.

Photocatalytic oxidation of organic compounds on semiconductors provides a mild approach for organic synthesis and solar energy utilization. Herein, we identify the key points for the photocatalytic oxidation over Pt-loaded Rh-doped strontium titanate allowing the conversion of alcohols efficiently and selectively to aldehydes and ketones under anaerobic conditions and visible light with an apparent quantum efficiency of pure benzyl alcohol oxidation at 420 nm of ≤49.5%. Mechanistic investigations suggest that thermodynamically the controlled valence band edge position via Rh doping provides a suitable oxidation ability of photogenerated holes, avoiding the powerful hydroxyl radical intermediates prone to overoxidation resulting in high selectivity. Kinetically, oxygen vacancies induced by Rh3+ substitution in the SrTiO3 lattice not only favor the dissociative adsorption of alcohols yielding alkoxy species but also induce the weakening of the α-C-H bond facilitating its cleavage by the photogenerated holes. Pt nanoparticles deposited as a cocatalyst contribute to the final hydrogen evolution.

Electric vehicles (EVs), when powered with sustainable sources of electricity, can contribute to the mitigation of climate change through reduced greenhouse gas emissions. The Canadian province of British Columbia (BC) is an attractive location for EV deployment because ∼85% of its electricity is sourced from large hydropower. The driving ranges of EVs and their potential to reduce local emissions mean they are well suited to urban contexts, where most residential buildings in BC are located. The challenges associated with installing new charging stations, particularly in Multi-Unit Residential Buildings (MURBs), can become barriers to uptake of EVs. In this study, we develop a conceptual framework to identify the challenges, potential barriers and stakeholders involved in the process of charging infrastructure installation in MURBs. We establish four main domains to this problem, each of which involves specific stakeholders: charging infrastructure installation, building limitations, governance issues and parking availability. Mapping out these problem domains using decision-making flow diagrams allows us to characterize their internal dynamics and the relationships between stakeholders. As EV markets continue to grow both in Canada and across the world, a better understanding of barriers to stakeholders in these residential settings is essential for informing policy interventions.

Current thermal comfort standards use Predicted Mean Vote (PMV) classes as the compliance criteria despite previous critiques. The implicit assumption is that a narrower PMV range ensures higher thermal acceptability among building occupants. However, our analysis of a global database of thermal comfort field studies demonstrates that PMV classes are not appropriate design compliance criteria, and reinforces the need for a new and robust approach to thermal comfort compliance assessment. We compared two statistical methods to derive acceptable temperature ranges from occupant responses applied one to the ASHRAE Global Thermal Comfort Database II. Derived acceptable temperature ranges in real buildings (7.4K-12.2 K) using this new method are wider than the current standards mandate (2 K-6K). Our findings support the call for a relaxation of suggested temperature ranges in thermal comfort standards so as to minimize unnecessary space conditioning. The proposed data-driven statistical methods to determine temperature design compliance criteria are viewed as an important step forward in the age of continuous and pervasive monitoring and the associated large databases of building comfort measurements.

Ruminiclostridium thermocellum is one of the most promising candidates for consolidated bioprocessing (CBP) of low-cost lignocellulosic materials to biofuels but it still shows poor performance in its ability to deconstruct untreated lignocellulosic substrates. One promising approach to increase R. thermocellum’s rate of hydrolysis is to co-culture this cellulose-specialist with partners that possess synergistic hydrolysis enzymes and metabolic capabilities. We have created co-cultures of R. thermocellum with two hemicellulose utilizers, Ruminiclostridium stercorarium and Thermoanaerobacter thermohydrosulfuricus, both of which secrete xylanolytic enzymes and utilize the pentose oligo- and monosaccharides that inhibit R. thermocellum’s hydrolysis and metabolism. When grown on milled wheat straw, the co-cultures were able to solubilize up to 58% more of the total polysaccharides than the R. thermocellum mono-culture control. Repeated passaging of the co-cultures on wheat straw yielded stable populations with reduced R. thermocellum cell numbers, indicating competition for cellodextrins released from cellulose hydrolysis, although these stabilized co-cultures were still able to outperform the mono-culture controls. Repeated passaging on Avicel cellulose also yielded stable populations. Overall, the observed synergism suggests that co-culturing R. thermocellum with other members is a viable option for increasing the rate and extent of untreated lignocellulose deconstruction by R. thermocellum for CBP purposes.

Ombrotrophic peat underlain by permafrost has been used to reconstruct past atmospheric mercury (Hg) deposition. Here, we analyze a core collected from a rapidly aggrading, raised peat bog near Daw...

Achieving meaningful reductions in greenhouse gas emissions from the global transportation sector will rely on a large-scale transition to electric vehicles (EVs). Many governments aim to encourage the uptake of EVs in cities, because urban areas are well suited to EV driving ranges and stand to benefit hugely from reduced local emissions. In the Canadian province of British Columbia (BC), where clean renewable electricity sourcing makes EV deployment an attractive proposition, over a quarter of residents live in Multi-Unit Residential Buildings (MURBs), most of which are not equipped with EV charging infrastructure. In a related study, Lopez-Behar et al. (accepted) explored the challenges and decision-making processes involved in the installation of EV charging infrastructure in MURBs in BC, from the perspective of different stakeholders. Here, we build on those findings to map out and analyze feedback loops within this system using a Causal Loop Diagram (CLD). We then present potential demand-focused policy interventions to address the issues raised by our modelling results, grouped into three categories: financial/fiscal, regulatory and information/awareness measures. Financial/fiscal policy measures include creating incentives for EV owners and extending them to the building owners, and programs to incentivize and provide financial aid for building owners to develop building retrofit plans. Regulatory policy measures include addressing the rights and obligations of the stakeholders and making mandatory the installation of charging stations in new MURBs. Information/awareness policy measures include expanding the existing guidelines and informing the development of a long-term EV charging infrastructure plan. Our policy recommendations are designed to inform the interventions of municipal and provincial governments in BC, but could also be relevant to many urban EV markets worldwide.

A point visibility graph is a graph induced by a set of points in the plane where the vertices of the graph represent the points in the point set and two vertices are adjacent if and only if no other point from the point set lies on the line segment between the two corresponding points. The set of all point visibility graphs form a graph class which is examined from a computational complexity perspective in this paper. We show NP-hardness for several classic graph problems on point visibility graphs such as Feedback Vertex Set , Longest Induced Path , Bisection and F - Free Vertex Deletion (for certain sets F ). Furthermore, we consider the complexity of the Dominating Set problem on point visibility graphs of points on a grid.

The functional composite of metal nanoparticles (NPs) and defect-engineered metal–organic frameworks (DE-MOFs), NPs@DE-MOFs, is an emerging field of MOF materials chemistry. Herein, we report on a series of novel Pd-NPs@DE-HKUST-1(Cu/Pd) catalysts containing both micro- and mesopores through the incorporation of the defect-generating linker 2,6-pyridyldicarboxylate (pydc). The Pd NPs are formed by partial reduction of the Pd2+ sites of the pristine mixed-metal DE-HKUST-1(Cu/Pd) with methanol. The size regime and the spatial distribution of the Pd NPs can be controlled by the amount of framework-incorporated pydc. The samples exhibit superior catalytic activity in the aerobic oxidation of cinnamyl alcohol as compared to the parent HKUST-1.

In growing plant cells, parallel ordering of microtubules (MTs) along the inner surface of the cell membrane influences the direction of cell expansion and thereby plant morphology. For correct expansion of organs that primarily grow by elongating, such as roots and stems, MTs must bend in the high-curvature direction along the cylindrically shaped cell membrane in order to form the required circumferential arrays. Computational studies, which have recapitulated the self-organization of these arrays, ignored MT mechanics and assumed MTs follow geodesics of the cell surface. Here, we show, through analysis of a derived Euler-Lagrange equation, that an elastic MT constrained to a cylindrical surface will deflect away from geodesics and toward low curvature directions to minimize bending energy. This occurs when the curvature of the cell surface is relatively high for a given anchor density. In the limit of infinite anchor density, MTs always follow geodesics. We compare our analytical predictions to measured curvatures and anchor densities and find that the regime in which cells are forming these cortical arrays straddles the region of parameter space in which arrays must form under the antagonistic influence of this mechanically induced deflection. Although this introduces a potential obstacle to forming circumferentially orientated arrays that needs to be accounted for in the models, it also raises the question of whether plants use this mechanical phenomenon to regulate array orientation. The model also constitutes an elegant generalization of the classical Euler-bucking instability along with an intrinsic unfolding of the associated pitchfork bifurcation., To appear in SIAM Journal on Applied Mathematics (SIAP); v1->v2: change of title and reorganization of the presentation of the results

Information about the survival of species is important in many ecological applications. Yet, the estimation of a species’ natural mortality rate M remains a major problem in the management and conservation of wild populations, often circumvented by applying empirical equations that relate mortality to other traits that are more easily observed. We show that mean adult M can be approximated from the general law of decay if the average maximum age reached by individuals in a cohort is known. This is possible because the proportion P of individuals surviving to the average maximum age in a cohort is surprisingly similar across a wide range of examined species at 1.5%. The likely reason for the narrow range of P is a universal increase in the rate of mortality near the end of life, providing strong evidence that the evolutionary theories of ageing are the norm in natural populations., Dureuil and Froese present a universal equation for estimating the mean adult mortality rate in natural populations. This equation is based on remarkable similarities in survival to average maximum age across a wide range of species.

The Bering Land Bridge (BLB) last connected Eurasia and North America during the Late Pleistocene. Although the BLB would have enabled transfers of terrestrial biota in both directions, it also acted as an ecological filter whose permeability varied considerably over time. Here we explore the possible impacts of this ecological corridor on genetic diversity within, and connectivity among, populations of a once wide-ranging group, the caballine horses (Equus spp.). Using a panel of 187 mitochondrial and eight nuclear genomes recovered from present-day and extinct caballine horses sampled across the Holarctic, we found that Eurasian horse populations initially diverged from those in North America, their ancestral continent, around 1.0–0.8 million years ago. Subsequent to this split our mitochondrial DNA analysis identified two bidirectional long-range dispersals across the BLB ~875–625 and ~200–50 thousand years ago, during the Middle and Late Pleistocene. Whole genome analysis indicated low levels of gene flow between North American and Eurasian horse populations, which probably occurred as a result of these inferred dispersals. Nonetheless, mitochondrial and nuclear diversity of caballine horse populations retained strong phylogeographical structuring. Our results suggest that barriers to gene flow, currently unidentified but possibly related to habitat distribution across Beringia or ongoing evolutionary divergence, played an important role in shaping the early genetic history of caballine horses, including the ancestors of living horses within Equus ferus. © 2021 John Wiley & Sons Ltd 19-05-00477, AAAA-A19-119032590102-7; National Science Foundation, NSF: ARC-1417036; Gordon and Betty Moore Foundation, GBMF: 3804; University of California, Santa Cruz, UCSC; U.S. Bureau of Land Management, BLM; Horizon 2020 Framework Programme, H2020: 681605; Seventh Framework Programme, FP7: IEF-302617; Natural Sciences and Engineering Research Council of Canada, NSERC; Marie Curie; European Research Council, ERC; Svenska Forskningsrådet Formas: 2018-01640; Russian Foundation for Basic Research, РФФИ: 18-04-00327; Knut och Alice Wallenbergs Stiftelse; Vetenskapsrådet, VR; Science for Life Laboratory, SciLifeLab We are grateful to the placer gold mining community, the Tr’ondëk Hwëch’in First Nation, and the Vuntut Gwitchin First Nation for their collaboration and support with our research in Yukon. Tamara Pico, Sarah Crump and Paul Koch provided advice interpreting the palaeoclimate of Beringia. Data generation was supported with funds from NSF ARC-1417036, the Gordon & Betty Moore Foundation (no. 3804) and the American Wild Horse Campaign. A.O.V. was additionally supported by a UCSC Chancellor’s Dissertation Year Fellowship and the CANA Foundation. M.T. and D.G. were supported by the Russian Foundation for Basic Research (project 18-04-00327), and L.E. by a Marie-Curie Intra-European fellowship (FP7, IEF-302617). G.B. is supported by the Federal theme of Zoological Institute of the Russian Academy of Sciences no. AAAA-A19-119032590102-7. S.V. was funded by the Russian Foundation for Basic Research, Grant 19-05-00477. L.D. acknowledges support from FORMAS (project 2018-01640). D.F. was supported by the Natural Science and Engineering Research Council. P.G. and D.M. are supported by the Bureau of Land Management. We acknowledge support from Science for Life Laboratory, the Knut and Alice Wallenberg Foundation, the National Genomics Infrastructure funded by the Swedish Research Council, and Uppsala Multidisciplinary Center for Advanced Computational Science for assistance with massively parallel sequencing and access to the UPPMAX computational infrastructure. L.O. received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement 681605). We are grateful to the placer gold mining community, the Tr?ond?k Hw?ch?in First Nation, and the Vuntut Gwitchin First Nation for their collaboration and support with our research in Yukon. Tamara Pico, Sarah Crump and Paul Koch provided advice interpreting the palaeoclimate of Beringia. Data generation was supported with funds from NSF ARC-1417036, the Gordon & Betty Moore Foundation (no. 3804) and the American Wild Horse Campaign. A.O.V. was additionally supported by a UCSC Chancellor?s Dissertation Year Fellowship and the CANA Foundation. M.T. and D.G. were supported by the Russian Foundation for Basic Research (project 18-04-00327), and L.E. by a Marie-Curie Intra-European fellowship (FP7, IEF-302617). G.B. is supported by the Federal theme of Zoological Institute of the Russian Academy of Sciences no. AAAA-A19-119032590102-7. S.V. was funded by the Russian Foundation for Basic Research, Grant 19-05-00477. L.D. acknowledges support from FORMAS (project 2018-01640). D.F. was supported by the Natural Science and Engineering Research Council. P.G. and D.M. are supported by the Bureau of Land Management. We acknowledge support from Science for Life Laboratory, the Knut and Alice Wallenberg Foundation, the National Genomics Infrastructure funded by the Swedish Research Council, and Uppsala Multidisciplinary Center for Advanced Computational Science for assistance with massively parallel sequencing and access to the UPPMAX computational infrastructure. L.O. received funding from the European Research Council (ERC) under the European Union?s Horizon 2020 research and innovation programme (grant agreement 681605).

The unknown status of inland fish stocks hinders their sustainable management. Therefore, increasing stock status information is important for sustainable inland fisheries. Fisheries reference points were estimated for five exploited fish species (11 stocks) in the Lake Edward system, East Africa, which is one of the most productive inland water systems. The aim was to ascertain the status of the fisheries and establish reference points for effective management. The reference points were based on four linked stock assessment approaches for data‐limited fisheries. Estimates showed poor stock status with the stocks defined as either collapsed, recruitment impaired or overfished. However, higher catches could be obtained under sustainable management. Estimates of maximum sustainable yield (MSY) and supporting biomass (Bmsy) are provided for 10 of the stocks as targets for rebuilding plans. The immediate target of management should be rebuilding biomass to Bmsy. Applicable measures include shifting length at first capture to the length that maximizes catch without endangering size structure and biomass, and livelihood diversification out of fisheries.

In any finite system, the presence of a non-zero permanent electric dipole moment (EDM) would indicate CP violation beyond the small violation predicted in the Standard Model. Here, we use the ab initio no-core shell model (NCSM) framework to theoretically investigate the magnitude of the nuclear EDM. We calculate EDMs of several light nuclei using chiral two- and three-body interactions and a PT-violating Hamiltonian based on a one-meson-exchange model. We present a benchmark calculation for $^3$He, as well as results for the more complex nuclei $^{6,7}$Li, $^9$Be, $^{10,11}$B, $^{13}$C, $^{14,15}$N, and $^{19}$F. Our results suggest that different nuclei can be used to probe different terms of the PT violating interaction. These calculations allow us to suggest which nuclei may be good candidates in the search for a measurable permanent electric dipole moment., 6 pages, 3 figures, matches published version

International audience; The reformed Common Fisheries Policy of the EU, in force since 2014, stipulates that overfishing by the fleets of its member states has to end latest in the year 2020. This study examines exploitation and status of 119 stocks fished by 20 countries in the Northeast Atlantic. In the year 2018, about 40% of the stocks were still subject to overfishing (F > Fmsy), about 34% of the stocks were outside safe biological limits (B < Bpa) and about 68% of the stocks were too small to produce maximum sustainable yields (B < Bmsy). Reduction in the number of overfished stocks has stalled, possible because of an agreement between the European Commission (EC) and the International Council for the Exploration of the Seas (ICES), its advisory body for total allowed catches (TACs), wherein the EC requests ICES to give TAC advice leading to overfishing for many stocks. Scientific advice is often overruled or ignored by politicians/fisheries ministers, whose main objective is to get us much quota as possible for their country. As a result, of the TACs set for 2020, about 46% exceeded scientific advice, suggesting that the goal of ending overfishing in 2020 will not be met.

We consider the numerical construction of minimal Lagrangian graphs, which is related to recent applications in materials science, molecular engineering, and theoretical physics. It is known that this problem can be formulated as an additive eigenvalue problem for a fully nonlinear elliptic partial differential equation. We introduce and implement a two-step generalized finite difference method, which we prove converges to the solution of the eigenvalue problem. Numerical experiments validate this approach in a range of challenging settings. We further discuss the generalization of this new framework to Monge-Ampère type equations arising in optimal transport. This approach holds great promise for applications where the data does not naturally satisfy the mass balance condition, and for the design of numerical methods with improved stability properties.

The SARS‐CoV‐2 pandemic has created a great demand for a better understanding of the spread of viruses in indoor environments. A novel measurement system consisting of one portable aerosol‐emitting mannequin (emitter) and a number of portable aerosol‐absorbing mannequins (recipients) was developed that can measure the spread of aerosols and droplets that potentially contain infectious viruses. The emission of the virus from a human is simulated by using tracer particles solved in water. The recipients inhale the aerosols and droplets and quantify the level of solved tracer particles in their artificial lungs simultaneously over time. The mobile system can be arranged in a large variety of spreading scenarios in indoor environments and allows for quantification of the infection probability due to airborne virus spreading. This study shows the accuracy of the new measurement system and its ability to compare aerosol reduction measures such as regular ventilation or the use of a room air purifier.

Catastrophic meltwater drainage from glacial Lake Agassiz has been hypothesised as a trigger for large-scale ocean circulation change initiating the Younger Dryas cold reversal. Here we quantify the flood discharge that formed the northwestern outlet of Lake Agassiz using a one-dimensional step-backwater model and a zero-dimension gradual-incision model. Applying these two independent models, we estimate a peak discharge range of 1.8-2.5 × 106 m3 s-1 and a flood volume of ∼21,000 km3. Such a discharge can only be derived from Lake Agassiz rather than one of the two smaller regional glacial lakes: Churchill or Meadow. When coupled with existing ice margin chronologies, these results demonstrate that the northwestern outlet of Lake Agassiz provides a viable link for catastrophic meltwater to drain to the Arctic Ocean over a 5-10 month period during the Younger Dryas, though it is unclear whether this was near its beginning., This research was funded by the Natural Sciences and Engineering Research Council (D.F.), the Canada Research Chairs Program (D.F.) and a Primus fellowship from Charles University (M.M.). We thank the editor, Mathieu Morlighem, and reviewers, Andy Breckenridge and Julian Murton. Data is available through Government of Alberta (2017). Government of Alberta (2017). LiDAR Data Archives. Data provided under license and with project specific data sharing agreement by the Archaeological Survey of Alberta, Culture, Multiculturalism, and the Status of Women. Edmonton, Alberta via geodiscoveralberta@gov.ab.ca through https://geodiscover.alberta.ca/geoportal/#searchPanel

In this review, we describe some of the central philosophical issues facing origins-of-life research and provide a targeted history of the developments that have led to the multidisciplinary field of origins-of-life studies. We outline these issues and developments to guide researchers and students from all fields. With respect to philosophy, we provide brief summaries of debates with respect to (1) definitions (or theories) of life, what life is and how research should be conducted in the absence of an accepted theory of life, (2) the distinctions between synthetic, historical, and universal projects in origins-of-life studies, issues with strategies for inferring the origins of life, such as (3) the nature of the first living entities (the “bottom up” approach) and (4) how to infer the nature of the last universal common ancestor (the “top down” approach), and (5) the status of origins of life as a science. Each of these debates influences the others. Although there are clusters of researchers that agree on some answers to these issues, each of these debates is still open. With respect to history, we outline several independent paths that have led to some of the approaches now prevalent in origins-of-life studies. These include one path from early views of life through the scientific revolutions brought about by Linnaeus (von Linn.), Wöhler, Miller, and others. In this approach, new theories, tools, and evidence guide new thoughts about the nature of life and its origin. We also describe another family of paths motivated by a” circularity” approach to life, which is guided by such thinkers as Maturana & Varela, Gánti, Rosen, and others. These views echo ideas developed by Kant and Aristotle, though they do so using modern science in ways that produce exciting avenues of investigation. By exploring the history of these ideas, we can see how many of the issues that currently interest us have been guided by the contexts in which the ideas were developed. The disciplinary backgrounds of each of these scholars has influenced the questions they sought to answer, the experiments they envisioned, and the kinds of data they collected. We conclude by encouraging scientists and scholars in the humanities and social sciences to explore ways in which they can interact to provide a deeper understanding of the conceptual assumptions, structure, and history of origins-of-life research. This may be useful to help frame future research agendas and bring awareness to the multifaceted issues facing this challenging scientific question., This project/publication was supported by the ELSI Origins Network (EON), which is supported by a grant from the John Templeton Foundation. T.F.’s work on this article was supported by an ELSI Origins Network (EON) Long-Term Visitor Award and by an UNAM-DGAPA-PAPIIT project (IA104717).

Highlights: • 1st global long-term fishery biomass trends evaluation of 1300 exploited marine populations. • Decline in average fishery biomass observed across oceans and climate zones. • Systemic wide-spread overfishing of the world's coastal and continental shelf water. Abstract: This contribution presents time series of the ‘fishery biomass’ of fish populations, defined as the weight (whole-body, wet weight) of the in-water part of a fishable population, i.e., that part of a population (also called ‘stock’) that is exposed to a certain fishing gear. Detailed data of this type are only available for a limited number of species that are targets of the fisheries in the waters of economically developed regions, such as Europe, the USA, Canada or Australia. However, similar fishery biomass assessments are generally lacking for developing countries, even for many of their most heavily fished species. Here, an estimation of the long-term fishery biomass trends of 1320 fish and invertebrate populations for 483 species exploited by fisheries in the 232 coastal Marine Ecoregions (MEs) around the world was undertaken. Fishery biomass trends were derived using the Bayesian CMSY stock assessment method applied to the global fisheries catch database for 1950–2014 as reconstructed by the Sea Around Us for every maritime fishing country in the world. Overall, the results suggest a consistent decline in the fishery biomass of exploited populations, in virtually all climatic zones and ocean basins in the world. The only zone with currently higher fishery biomass than in 1950 is the northern Pacific polar-boreal zone, likely due to environmental changes that occurred in the region positively affecting fish populations, combined with prudent management of the fisheries. For populations in MEs that are known to have highly questionable catch statistics, the results suggested smaller declines in fishery biomass than likely occurred in reality, implying that these results do not exaggerate declining trends in fishery biomass. This study used informative Bayesian priors to improve the trend analyses in areas where systematic stock assessments were conducted. The use of these independent assessments reduced the uncertainty associated with the findings of this study.

Despite the presence of well-documented changes in vegetation and faunal communities at the Pleistocene-Holocene transition, it is unclear whether similar shifts occurred in soil microbes. Recent studies do not show a clear connection between soil parameters and community structure, suggesting permafrost microbiome-climate studies may be unreliable. However, the majority of the permafrost microbial ecological studies have been performed only in either Holocene- or Pleistocene-aged sediments and not on permafrost that formed across the dramatic ecosystem reorganization at the Pleistocene-Holocene transition. In our study, we used permafrost recovered in proximity to the Pleistocene-Holocene transition subsampled under strict sterile conditions developed for ancient DNA studies. Our ordination analyses of microbial community composition based on 16S RNA genes and chemical composition of the soil samples resulted into two distinct clusters based on whether they were of late Pleistocene or Holocene age, while samples within an epoch were more similar than those across the boundary and did not result in age based separation. Between epochs, there was a statistically significant correlation between changes in OTU composition and soil chemical properties, but only Ca and Mn were correlated to OTU composition within Holocene aged samples; furthermore, no chemical parameters were correlated to OTU composition within Pleistocene aged samples. Thus, the results indicate that both soil chemical and microbial parameters are fairly stable until a threshold, driven by climate change in our study, is crossed, after which there is a shift to a new steady state. Modern anthropogenic climate change may lead to similar transitions in state for soil biogeochemical systems and microbial communities in Arctic regions.

Brexit creates a systemic shock that provides a unique opportunity for the UK to implement a new sustainable Fisheries Policy to better manage the multiple stocks on which future fishers will depend on leaving the European Union. At the same time, the global slowdown of commercial fishing as a result of COVID-19 has reduced pressure on some threatened stocks to levels not seen since the Second World War. In combination, Brexit and the COVID-19 slowdown have created a unique opportunity to facilitate the recovery of a threatened resource. Nevertheless, challenges remain as fisheries represent only 0.12% of UK economic output, presenting a risk that opportunities for more sustainable management will be lost during wider trade negotiations. Reduced fishing pressure during the COVID-19 era will enable stocks an opportunity to recover if supported by a new UK Fisheries Policy that focuses on: (a) re-establishing the role of Maximum Sustainable Yield to set limits that enable the recovery of fish populations initiated during the COVID-19 era; (b) ensuring that catch targets are set with the aim to maintain biomass at 120% of that which will achieve Maximum Sustainable Yield; (c) improving coherent resource management that also considers the expensive use of carbon associated with unsustainable fishing, and the need to protect fish throughout their life-cycle; and (d) constructing and effectively enforcing protection of a resilient network of Marine Protected Areas despite potential protests from EU member states., Highlights • Brexit provides a unique opportunity to develop a fisheries policy that will lead the world in sustainable use of marine ecosystems. • The COVID-19 slowdown has reduced fishing pressure to levels not seen since WW2 and is an opportunity to kick-start recovery of depleted stocks. • The concept of Maximum Sustainable Yields has been misused resulting in the degradation of stocks so that many are currently threatened. • Marine fisheries represent only 0.12% of UK economic output, risking the opportunity to advance sustainability during wider trade negotiations. • This article provides recommendations for a policy to deliver sustainable resource management and conservation to benefit future generations.

We are reinvestigating the hyperfine structure of sodium using a fully relativistic multiconfiguration approach. In the fully relativistic approach, the computational strategy somewhat differs from the original nonrelativistic counterpart used in J\"onsson et al. (Phys. Rev. A 53 (1996) 4021). Numerical instabilities force us to use a layer-by-layer approach that has some broad unexpected effects. Core correlation is found to be significant and therefore requires to be described in an adequate orbital basis. The natural-orbital basis provides an interesting alternative to the orbital basis from the layer-by-layer approach, allowing us to overcome some deficits of the latter, giving rise to magnetic dipole hyperfine structure constant values in excellent agreement with observations. Effort is made to assess the reliability of the natural-orbital bases and to illustrate their efficiency., Comment: 12 tables, 2 figures

This synthesis of the literature on incorporation of genetic gain into growth and yield models reveals a fundamental challenge associated with the rapid progress in genetics and breeding and limited empirical data on improved stands. Model improvements depend on a better understanding of both the biological basis for gain and of interactions between genetic and non-genetic factors on gain. Continued development of new genetic varieties of trees requires accurate stand growth and yield models to predict growth trajectories and genetic gain of the new varieties using early-age growth data. To identify how the effects of genetic variety on growth and yield models could be analyzed and genetic information could be incorporated into these models for accurate growth simulation and improved yield prediction of genetically improved stands. Genetic variety may affect one or several of the asymptotic parameters, shape parameters, and rate parameters of growth and yield models, which can be assessed by testing the parameter differences of the models. After determination of the influence of genetic varieties on model parameters and considering the existing general stand growth equation, the genetic gain can be incorporated into growth and yield models by calculation of genetic gain multipliers, adjustment of the site index, and calibration of the new model parameters. Accurate and effective growth and yield models for genetically improved stands require a better understanding of the effects of genetics, environment, and silviculture measures on tree and stand growth.

Not as advertised Marine protected areas (MPAs) have increasingly designated globally, with an associated advertised percentage of area protected. However, recent research has made it clear that many MPAs are not actually protecting marine biodiversity. Dureuil et al. focused on European MPAs and found that trawling, one of the most damaging types of fishing, occurs widely in these areas. Furthermore, using sharks and rays as indicator species, they found that many MPAs are failing to protect vulnerable species. Science , this issue p. 1403