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51.
Subterranean estuaries (STEs) are important coastal biogeochemical reactors facilitating unique niches for microbial communities. A common approach in determining STE greenhouse gas and nutrient fluxes is to use terrestrial endmembers, not accounting for microbially mediated transformations throughout the STE. As such, the microbial ecology and spatial distribution of specialists that cycle compounds in STEs remain largely underexplored. In this study, we applied 16S rRNA amplicon sequencing with paired biogeochemical characterisations to spatially evaluate microbial communities transforming greenhouse gases and nutrients in an STE. We show that methanogens are most prevalent at the terrestrial end (up to 2.81% relative abundance) concomitant to the highest porewater methane, carbon dioxide and dissolved organic carbon concentrations (0.41 ± 0.02 μM, 273.31 ± 6.05 μM and 0.51 ± 0.02 mM, respectively). Lower ammonium concentrations corresponded with abundant nitrifying and ammonia-oxidising prokaryotes in the mixing zone (up to 11.65% relative abundance). Methane, ammonium and dissolved organic carbon concentrations all decreased by >50% from the terrestrial to the oceanic end of the 15 m transect. This study highlights the STE's hidden microbiome zonation, as well as the importance of accounting for microbial transformations mitigating nutrient and greenhouse gas fluxes to the coastal ecosystems.  相似文献   
52.
Research needs a balance of risk‐taking in “breakthrough projects” and gradual progress. For building a sustainable knowledge base, it is indispensable to provide support for both. Subject Categories: Careers, Economics, Law & Politics, Science Policy & Publishing

Science is about venturing into the unknown to find unexpected insights and establish new knowledge. Increasingly, academic institutions and funding agencies such as the European Research Council (ERC) explicitly encourage and support scientists to foster risky and hopefully ground‐breaking research. Such incentives are important and have been greatly appreciated by the scientific community. However, the success of the ERC has had its downsides, as other actors in the funding ecosystem have adopted the ERC’s focus on “breakthrough science” and respective notions of scientific excellence. We argue that these tendencies are concerning since disruptive breakthrough innovation is not the only form of innovation in research. While continuous, gradual innovation is often taken for granted, it could become endangered in a research and funding ecosystem that places ever higher value on breakthrough science. This is problematic since, paradoxically, breakthrough potential in science builds on gradual innovation. If the value of gradual innovation is not better recognized, the potential for breakthrough innovation may well be stifled.
While continuous, gradual innovation is often taken for granted, it could become endangered in a research and funding ecosystem that places ever higher value on breakthrough science.
Concerns that the hypercompetitive dynamics of the current scientific system may impede rather than spur innovative research have been voiced for many years (Alberts et al, 2014). As performance indicators continue to play a central role for promotions and grants, researchers are under pressure to publish extensively, quickly, and preferably in high‐ranking journals (Burrows, 2012). These dynamics increase the risk of mental health issues among scientists (Jaremka et al, 2020), dis‐incentivise relevant and important work (Benedictus et al, 2016), decrease the quality of scientific papers (Sarewitz, 2016) and induce conservative and short‐term thinking rather than risk‐taking and original thinking required for scientific innovation (Alberts et al, 2014; Fochler et al, 2016). Against this background, strong incentives for fostering innovative and daring research are indispensable.  相似文献   
53.
Bacteria have adaptive immunity against viruses (phages) in the form of CRISPR-Cas immune systems. Currently, 6 types of CRISPR-Cas systems are known and the molecular study of three of these has revealed important molecular differences. It is unknown if and how these molecular differences change the outcome of phage infection and the evolutionary pressure the CRISPR-Cas systems faces. To determine the importance of these molecular differences, we model a phage outbreak entering a population defending exclusively with a type I/II or a type III CRISPR-Cas system. We show that for type III CRISPR-Cas systems, rapid phage extinction is driven by the probability to acquire at least one resistance spacer. However, for type I/II CRISPR-Cas systems, rapid phage extinction is characterized by an a threshold-like behaviour: any acquisition probability below this threshold leads to phage survival whereas any acquisition probability above it, results in phage extinction. We also show that in the absence of autoimmunity, high acquisition rates evolve. However, when CRISPR-Cas systems are prone to autoimmunity, intermediate levels of acquisition are optimal during a phage outbreak. As we predict an optimal probability of spacer acquisition 2 factors of magnitude above the one that has been measured, we discuss the origin of such a discrepancy. Finally, we show that in a biologically relevant parameter range, a type III CRISPR-Cas system can outcompete a type I/II CRISPR-Cas system with a slightly higher probability of acquisition.  相似文献   
54.
Zusammenfassung Es wird über die erfolgreiche Züchtung des perfekten Fruchtkörpers beiM. gypseum und, bei dem ihm nahe verwandtenEp. radiosulcatum var. flavum Szathmáry, 1940 mittels Erdbodenkulturen berichtet.Die Methode benutzte menschliche und tierische Haare, die einfach auf den Erdboden gelegt worden sind. Die Haare waren erst durch trockene Hitze sterilisiert und dann in 75% Methyl- oder Äthyl-alkohol aufbewahrt.Die jetzige Mitteilung behandelt hauptsächlich die Struktur, das Gerüst und Verzierung des Fruchtkörpers in den zwei benannten Gattungen.Das gleichzeitige Vorkommen der imperfekten und perfekten Formen der zwei Gattungen im Erdboden ist sehr häufig, ebenso wie ihre Vergesellschaftung mit anderen Gattungen der Dermatophyten.  相似文献   
55.
56.
  1. The young leaves are the main source of nucleic acids for population genetic studies in palm‐trees; however, the access to this tissue may be limited by specific features of each species. Using root tissues as an alternative source of nucleic acids could facilitate the sampling in large populations.
  2. This study tests root tissue viability as an alternative nucleic acid source (root versus. leaf) and explores different protocols (tissue storage and DNA extraction methods) to obtain high‐quality DNA samples.
  3. The results showed no significant differences in DNA concentration (603.7 vs. 599.1 ng/μl) and quality ratios (A260/280:2.1 vs. 1.9, and A260/230:2.1 vs. 2.0) for the comparisons of tissue source (leaf vs. root) and DNA extraction method (manual vs. kit). For tissue storage method, DNA concentration was significantly higher for root tissues stored in 70% and 90% alcohol solutions (692.8 and 822.6 ng/μl, respectively) versus those obtained from leaf tissue (603.7 ng/μl); however, for the quality parameters, no differences were found.
  4. Results showed the effective potential of using root tissue as an alternative source for nucleic acids, which could facilitate population sampling of palm‐tree species for future studies, and this methodological alternative could be applied to other plant systems with similar sampling challenges.
​  相似文献   
57.
The oomycete Albugo candida causes white rust of Brassicaceae, including vegetable and oilseed crops, and wild relatives such as Arabidopsis thaliana. Novel White Rust Resistance (WRR) genes from Arabidopsis enable new insights into plant/parasite co-evolution. WRR4A from Arabidopsis accession Columbia (Col-0) provides resistance to many but not all white rust races, and encodes a nucleotide-binding, leucine-rich repeat immune receptor. Col-0 WRR4A resistance is broken by AcEx1, an isolate of A. candida. We identified an allele of WRR4A in Arabidopsis accession Øystese-0 (Oy-0) and other accessions that confers full resistance to AcEx1. WRR4AOy-0 carries a C-terminal extension required for recognition of AcEx1, but reduces recognition of several effectors recognized by the WRR4ACol-0 allele. WRR4AOy-0 confers full resistance to AcEx1 when expressed in the oilseed crop Camelina sativa.  相似文献   
58.
The provision of healthcare in rural African communities is a highly complex and largely unsolved problem. Two main difficulties are the identification of individuals that are most likely affected by disease and the prediction of responses to health interventions. Social networks have been shown to capture health outcomes in a variety of contexts. Yet, it is an open question as to what extent social network analysis can identify and distinguish among households that are most likely to report poor health and those most likely to respond to positive behavioural influences. We use data from seven highly remote, post-conflict villages in Liberia and compare two prominent network measures: in-degree and betweenness. We define in-degree as the frequency in which members from one household are named by another household as a friends. Betweenness is defined as the proportion of shortest friendship paths between any two households in a network that traverses a particular household. We find that in-degree explains the number of ill family members, whereas betweenness explains engagement in preventative health. In-degree and betweenness independently explained self-reported health and behaviour, respectively. Further, we find that betweenness predicts susceptibility to, instead of influence over, good health behaviours. The results suggest that targeting households based on network measures rather than health status may be effective for promoting the uptake of health interventions in rural poor villages.  相似文献   
59.
  1. Most studies on how rising temperatures will impact terrestrial ectotherms have focused on single populations or multiple sympatric species. Addressing the thermal and energetic implications of climatic variation on multiple allopatric populations of a species will help us better understand how a species may be impacted by altered climates.
  2. We used eight years of thermal and behavioral data collected from four populations of Pacific rattlesnakes (Crotalus oreganus) living in climatically distinct habitat types (inland and coastal) to determine the field‐active and laboratory‐preferred body temperatures, thermoregulatory metrics, and maintenance energetic requirements of snakes from each population.
  3. Physical models showed that thermal quality was best at coastal sites, but inland snakes thermoregulated more accurately despite being in more thermally constrained environments. Projected increases of 1 and 2°C in ambient temperature result in an increase in overall thermal quality at both coastal and inland sites.
  4. Population differences in modeled standard metabolic rate estimates were driven by body size and not field‐active body temperature, with inland snakes requiring 1.6× more food annually than coastal snakes.
  5. All snakes thermoregulated with high accuracy, suggesting that small increases in ambient temperature are unlikely to impact the maintenance energetic requirements of individual snakes and that some species of large‐bodied reptiles may be robust to modest thermal perturbations under conservative climate change predictions.
​  相似文献   
60.
Understanding changes in terrestrial carbon balance is important to improve our knowledge of the regional carbon cycle and climate change. However, evaluating regional changes in the terrestrial carbon balance is challenging due to the lack of surface flux measurements. This study reveals that the terrestrial carbon uptake over the Republic of Korea has been enhanced from 1999 to 2017 by analyzing long‐term atmospheric CO2 concentration measurements at the Anmyeondo Station (36.53°N, 126.32°E) located in the western coast. The influence of terrestrial carbon flux on atmospheric CO2 concentrations (ΔCO2) is estimated from the difference of CO2 concentrations that were influenced by the land sector (through easterly winds) and the Yellow Sea sector (through westerly winds). We find a significant trend in ΔCO2 of ?4.75 ppm per decade (p < .05) during the vegetation growing season (May through October), suggesting that the regional terrestrial carbon uptake has increased relative to the surrounding ocean areas. Combined analysis with satellite measured normalized difference vegetation index and gross primary production shows that the enhanced carbon uptake is associated with significant nationwide increases in vegetation and its production. Process‐based terrestrial model and inverse model simulations estimate that regional terrestrial carbon uptake increases by up to 18.9 and 8.0 Tg C for the study period, accounting for 13.4% and 5.7% of the average annual domestic carbon emissions, respectively. Atmospheric chemical transport model simulations indicate that the enhanced terrestrial carbon sink is the primary reason for the observed ΔCO2 trend rather than anthropogenic emissions and atmospheric circulation changes. Our results highlight the fact that atmospheric CO2 measurements could open up the possibility of detecting regional changes in the terrestrial carbon cycle even where anthropogenic emissions are not negligible.  相似文献   
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