Aim: While soil microorganisms play key roles in Earth's biogeochemical cycles, methodological constraints and sparse data have hampered our ability to describe and understand the global distribution ...of soil microbial biomass. Here, we present a comprehensive quantification of the environmental drivers of soil microbial biomass. Location: Global. Methods: We used a comprehensive global dataset of georeferenced soil microbial biomass estimates and high-resolution climatic and soil data.
Results: We show that microbial biomass carbon (C
Mic
)is primarily driven by moisture availability, with this single variable accounting for 34% of the global variance. For the microbial carbon-to-soil organic carbon ratio (C
Mic
/C
org
) soil nitrogen content was an equally important driver as moisture. In contrast, temperature was not a significant predictor of microbial biomass patterns at a global scale, while temperature likely has an indirect effect on microbial biomass by influencing rates of evapotranspiration and decomposition. As our models explain an unprecedented 50% of the global variance of C
Mic
and C
Mic
/C
Org
, we were able to leverage gridded environmental information to build the first spatially explicit global estimates of microbial biomass and quantified the global soil microbial carbon pool to equal 14.6 Pg C.
Main Conclusions: Our unbiased models allowed us to build the first global spatially explicit predictions of microbial biomass. These patterns show that soil microbial biomass is not primarily driven by temperature, but instead, biomass is more heterogeneous through the effects of moisture availability and soil nutrients. Our global estimates provide important data for integration into large-scale carbon and nutrient models that may imply a major step forward in our ability to predict the global carbon balance, now and in a future climate.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NMLJ, NUK, OILJ, PNG, SAZU, SBCE, SBMB, UL, UM, UPUK
The rise in wildfire frequency and severity across the globe has increased interest in secondary succession. However, despite the role of soil microbial communities in controlling biogeochemical ...cycling and their role in the regeneration of post‐fire vegetation, the lack of measurements immediately post‐fire and at high temporal resolution has limited understanding of microbial secondary succession. To fill this knowledge gap, we sampled soils at 17, 25, 34, 67, 95, 131, 187, 286, and 376 days after a southern California wildfire in fire‐adapted chaparral shrublands. We assessed bacterial and fungal biomass with qPCR of 16S and 18S and richness and composition with Illumina MiSeq sequencing of 16S and ITS2 amplicons. Fire severely reduced bacterial biomass by 47%, bacterial richness by 46%, fungal biomass by 86%, and fungal richness by 68%. The burned bacterial and fungal communities experienced rapid succession, with 5–6 compositional turnover periods. Analogous to plants, turnover was driven by “fire‐loving” pyrophilous microbes, many of which have been previously found in forests worldwide and changed markedly in abundance over time. Fungal secondary succession was initiated by the Basidiomycete yeast Geminibasidium, which traded off against the filamentous Ascomycetes Pyronema, Aspergillus, and Penicillium. For bacteria, the Proteobacteria Massilia dominated all year, but the Firmicute Bacillus and Proteobacteria Noviherbaspirillum increased in abundance over time. Our high‐resolution temporal sampling allowed us to capture post‐fire microbial secondary successional dynamics and suggest that putative tradeoffs in thermotolerance, colonization, and competition among dominant pyrophilous microbes control microbial succession with possible implications for ecosystem function.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
For millennia Indigenous communities worldwide have maintained diverse knowledge systems informed through careful observation of dynamics of environmental changes. Although Indigenous communities and ...their knowledge systems are recognized as critical resources for understanding and adapting to climate change, no comprehensive, evidence-based analysis has been conducted into how environmental studies engage Indigenous communities. Here we provide the first global systematic review of levels of Indigenous community participation and decision-making in all stages of the research process (initiation, design, implementation, analysis, dissemination) in climate field studies that access Indigenous knowledge. We develop indicators for assessing responsible community engagement in research practice and identify patterns in levels of Indigenous community engagement. We find that the vast majority of climate studies (87%) practice an extractive model in which outside researchers use Indigenous knowledge systems with minimal participation or decision-making authority from communities who hold them. Few studies report on outputs that directly serve Indigenous communities, ethical guidelines for research practice, or providing Indigenous community access to findings. Further, studies initiated with (in mutual agreement between outside researchers and Indigenous communities) and by Indigenous community members report significantly more indicators for responsible community engagement when accessing Indigenous knowledges than studies initiated by outside researchers alone. This global assessment provides an evidence base to inform our understanding of broader social impacts related to research design and concludes with a series of guiding questions and methods to support responsible research practice with Indigenous and local communities.
Acupuncture is recommended by the World Health Organization (WHO) as an alternative and complementary strategy for stroke treatment and for improving stroke care. Clinical trial and meta-analysis ...findings have demonstrated the efficacy of acupuncture in improving balance function, reducing spasticity, and increasing muscle strength and general well-being post-stroke. The mechanisms underlying the beneficial effects of acupuncture in stroke rehabilitation remain unclear. The aim of this study was to conduct a literature review, summarize the current known mechanisms in ischemic stroke rehabilitation through acupuncture and electroacupuncture (EA) therapy, and to detail the frequently used acupoints implicated in these effects. The evidence in this review indicates that five major different mechanisms are involved in the beneficial effects of acupuncture/EA on ischemic stroke rehabilitation: (1) Promotion of neurogenesis and cell proliferation in the central nervous system (CNS); (2) Regulation of cerebral blood flow in the ischemic area; (3) Anti-apoptosis in the ischemic area; (4) Regulation of neurochemicals; and, (5) Improvement of impaired long-term potentiation (LTP) and memory after stroke. The most frequently used acupoints in basic studies include Baihui (GV20), Zusanli (ST36), Quchi (LI11), Shuigou (GV26), Dazhui (GV14), and Hegu (LI4). Our findings show that acupuncture exerts a beneficial effect on ischemic stroke through modulation of different mechanisms originating in the CNS.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Nonlinear Kerr micro-resonators have enabled fundamental breakthroughs in the understanding of dissipative solitons, as well as in their application to optical frequency comb generation. However, the ...conversion efficiency of the pump power into a soliton frequency comb typically remains below a few percent. We fabricate and characterize a hybrid Mach-Zehnder ring resonator geometry, consisting of a micro-ring resonator embedded in an additional cavity with twice the optical path length of the ring. The resulting interferometric back coupling enables to achieve an unprecedented control of the pump depletion: pump-to-frequency comb conversion efficiencies of up to 55% of the input pump power is experimentally demonstrated with a soliton crystal comb. We assess the robustness of the proposed on-chip geometry by generating a large variety of dissipative Kerr soliton combs, which require a lower amount of pump power to be accessed, when compared with an isolated micro-ring resonator with identical parameters. Micro-resonators with feedback enable accessing new regimes of coherent soliton comb generation, and are well suited for comb applications in astronomy, spectroscopy and telecommunications.
We investigated organogel formation in dispersions of CW in safflower oil (SFO). Candelilla wax (CW) has as its main component hentriacontane (78.9%), a n-alkane with self assembly properties in ...organic solvents (i.e., vegetable oils). Results showed that, independent of the cooling rate (i.e., 1 °C/min and 10 °C/min) and gel setting temperature (T set), the CW organogels observed a thermoreversible behavior. This was evaluated by the behavior of thermal parameters that characterized organogel formation (gelation temperature, T g; heat of gelation, ΔHg) and melting (melting temperature, T p; heat of melting, ΔHM) after two heating-cooling cycles. For a given CW concentration (i.e., 0.5, 1.0, and 3%), the magnitude of ΔHM and T p and the structural organization of the organogel, depended on the cooling rate, the thermodynamic drive force for gelation, and the annealing process occurring at high Tset (i.e., 25 °C). At T set of 25 °C the microplatelet units that formed the organogel aggregated as a function of storage time, a process that resulted in an increase in organogel hardness. In contrast, at T set of 5 °C annealing occurred in a limited extent, but gels had higher solid fat content and microplatelet units of a smaller size than the gels obtained at 25 °C. The result was a three-dimensional network with greater hardness than the one obtained at 25 °C. The 3% CW organogels showed no phase separation up to 3 months at room temperature, with textures of potential use by the food industry.
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FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, UL, UM, UPUK, VKSCE, ZAGLJ
The immune response to Mycobacterium tuberculosis infection determines tuberculosis disease outcomes, yet we have an incomplete understanding of what immune factors contribute to a protective immune ...response. Neutrophilic inflammation has been associated with poor disease prognosis in humans and in animal models during M. tuberculosis infection and, therefore, must be tightly regulated. ATG5 is an essential autophagy protein that is required in innate immune cells to control neutrophil-dominated inflammation and promote survival during M. tuberculosis infection; however, the mechanistic basis for how ATG5 regulates neutrophil recruitment is unknown. To interrogate what innate immune cells require ATG5 to control neutrophil recruitment during M. tuberculosis infection, we used different mouse strains that conditionally delete Atg5 in specific cell types. We found that ATG5 is required in CD11c+ cells (lung macrophages and dendritic cells) to control the production of proinflammatory cytokines and chemokines during M. tuberculosis infection, which would otherwise promote neutrophil recruitment. This role for ATG5 is autophagy dependent, but independent of mitophagy, LC3-associated phagocytosis, and inflammasome activation, which are the most well-characterized ways that autophagy proteins regulate inflammation. In addition to the increased proinflammatory cytokine production from macrophages during M. tuberculosis infection, loss of ATG5 in innate immune cells also results in an early induction of TH17 responses. Despite prior published in vitro cell culture experiments supporting a role for autophagy in controlling M. tuberculosis replication in macrophages, the effects of autophagy on inflammatory responses occur without changes in M. tuberculosis burden in macrophages. These findings reveal new roles for autophagy proteins in lung resident macrophages and dendritic cells that are required to suppress inflammatory responses that are associated with poor control of M. tuberculosis infection.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
We describe and reflect on seven recurring critiques of the concept of ecosystem services and respective counter‐arguments. First, the concept is criticized for being anthropocentric, whereas others ...argue that it goes beyond instrumental values. Second, some argue that the concept promotes an exploitative human–nature relationship, whereas others state that it reconnects society to ecosystems, emphasizing humanity's dependence on nature. Third, concerns exist that the concept may conflict with biodiversity conservation objectives, whereas others emphasize complementarity. Fourth, the concept is questioned because of its supposed focus on economic valuation, whereas others argue that ecosystem services science includes many values. Fifth, the concept is criticized for promoting commodification of nature, whereas others point out that most ecosystem services are not connected to market‐based instruments. Sixth, vagueness of definitions and classifications are stated to be a weakness, whereas others argue that vagueness enhances transdisciplinary collaboration. Seventh, some criticize the normative nature of the concept, implying that all outcomes of ecosystem processes are desirable. The normative nature is indeed typical for the concept, but should not be problematic when acknowledged. By disentangling and contrasting different arguments we hope to contribute to a more structured debate between opponents and proponents of the ecosystem services concept.
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FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UL, UM, UPUK
Aim
To analyse the antimicrobial and biological properties of a new bioceramic intracanal medicament (Bio‐C Temp), and to compare it with two calcium hydroxide‐based intracanal medicaments (Calen® ...and UltraCal® XS).
Methodology
The direct contact and the crystal violet tests were performed to assess the antimicrobial activity of intracanal medicaments against Enterococcus faecalis. The cytocompatibility and the effect of the medication on the biology of the human osteoblast‐like cell line (Saos‐2) were evaluated with methylthiazole tetrazolium (MTT), neutral red, alkaline phosphatase activity and mineralization (alizarin red) assays. The data were analysed using one‐way anova and Tukey’s tests, two‐way anova and Bonferroni’s tests, or Kruskal–Wallis and Dunn’s tests (α = 0.05).
Results
Bio‐C Temp had significantly less antibacterial activity and biofilm biomass reduction than the other intracanal medicaments (P < 0.05). There was no difference in the viability of Saos‐2 exposed to the various intracanal medicaments, except regarding the 1 : 2 dilution, when the Bio‐C Temp group had significantly lower cell viability than the UltraCal® XS and Calen® groups (P < 0.05). Bio‐C Temp induced significantly greater ALP activity than the other intracanal medicaments (P < 0.05) at day 1. Calen® induced significantly greater deposition of mineralized nodules than the other intracanal medicaments (P < 0.05), and no difference was observed between Bio‐C Temp and UltraCal® XS (P > 0.05).
Conclusions
Bio‐C Temp had similar cytocompatibility at higher dilutions, and higher or similar induction of ALP activity and deposition of mineralized nodules in comparison with Calen® and UltraCal® XS. However, it had significantly less antibacterial and antibiofilm activity than Calen® and UltraCal® XS.
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BFBNIB, CMK, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Chemical synthesis of conjugate vaccines, consisting of a polysaccharide linked to a protein, can be technically challenging, and in vivo bacterial conjugations (bioconjugations) have emerged as ...manufacturing alternatives. Bioconjugation relies upon an oligosaccharyltransferase to attach polysaccharides to proteins, but currently employed enzymes are not suitable for the generation of conjugate vaccines when the polysaccharides contain glucose at the reducing end, which is the case for ~75% of Streptococcus pneumoniae capsules. Here, we use an O-linking oligosaccharyltransferase to generate a polyvalent pneumococcal bioconjugate vaccine with polysaccharides containing glucose at their reducing end. In addition, we show that different vaccine carrier proteins can be glycosylated using this system. Pneumococcal bioconjugates are immunogenic, protective and rapidly produced within E. coli using recombinant techniques. These proof-of-principle experiments establish a platform to overcome limitations of other conjugating enzymes enabling the development of bioconjugate vaccines for many important human and animal pathogens.
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