Establishing microbial baselines to identify indicators of coral reef health

Microorganisms make a significant contribution to reef ecosystem health and resilience via their critical role in mediating nutrient transformations, their interactions with macro-organisms and their provision of chemical cues that underpin the recruitment of diverse reef taxa. However, environmental changes often cause compositional and functional shifts in microbial communities that can have flow-on consequences for microbial-mediated processes. These microbial alterations may impact the health of specific host organisms and can have repercussions for the functioning of entire coral ecosystems. Assessing changes in reef microbial communities should therefore provide an early indicator of ecosystem impacts and would underpin the development of diagnostic tools that could help forecast shifts in coral reef health under different environmental states. Monitoring, management and active restoration efforts have recently intensified and diversified in response to global declines in coral reef health. Here we propose that regular monitoring of coral reef microorganisms could provide a rapid and sensitive platform for identifying declining ecosystem health that can complement existing management frameworks. By summarising the most common threats to coral reefs, with a particular focus on the Great Barrier Reef, and elaborating on the role of microbes in coral reef health and ecosystem stability, we highlight the diagnostic applicability of microbes in reef management programs. Fundamental to this objective is the establishment of microbial baselines for Australia's coral reefs.AIMS@JCU PhD Scholarship; GBRMPA Science Management Research Award; Advance Queensland PhD Scholarship; Portuguese Science and Technology Foundation (FCT) [SFRH/BPD/110285/2015

Comparative genome-centric analysis reveals seasonal variation in the function of coral reef microbiomes

Microbially mediated processes contribute to coral reef resilience yet, despite extensive characterisation of microbial community variation following environmental perturbation, the effect on microbiome function is poorly understood. We undertook metagenomic sequencing of sponge, macroalgae and seawater microbiomes from a macroalgae-dominated inshore coral reef to define their functional potential and evaluate seasonal shifts in microbially mediated processes. In total, 125 high-quality metagenome-assembled genomes were reconstructed, spanning 15 bacterial and 3 archaeal phyla. Multivariate analysis of the genomes relative abundance revealed changes in the functional potential of reef microbiomes in relation to seasonal environmental fluctuations (e.g. macroalgae biomass, temperature). For example, a shift from Alphaproteobacteria to Bacteroidota-dominated seawater microbiomes occurred during summer, resulting in an increased genomic potential to degrade macroalgal-derived polysaccharides. An 85% reduction of Chloroflexota was observed in the sponge microbiome during summer, with potential consequences for nutrition, waste product removal, and detoxification in the sponge holobiont. A shift in the Firmicutes:Bacteroidota ratio was detected on macroalgae over summer with potential implications for polysaccharide degradation in macroalgal microbiomes. These results highlight that seasonal shifts in the dominant microbial taxa alter the functional repertoire of host-associated and seawater microbiomes, and highlight how environmental perturbation can affect microbially mediated processes in coral reef ecosystems.Australian Government Department of Industry, Innovation and Science; Advance Queensland PhD Scholarship Great Barrier Reef Marine Park Authority Management Award National Environmental Science Program (NESP)info:eu-repo/semantics/publishedVersio

Concept Typicality Responses in the Semantic Memory Network

For decades concept typicality has been recognized as critical to structuring conceptual knowledge, but only recently has typicality been applied in better understanding the processes engaged by the neurological network underlying semantic memory. This previous work has focused on one region within the network – the Anterior Temporal Lobe (ATL). The ATL responds negatively to concept typicality (i.e., the more atypical the item, the greater the activation in the ATL). To better understand the role of typicality in the entire network, we ran an fMRI study using a category verification task in which concept typicality was manipulated parametrically. We argue that typicality is relevant to both amodal feature integration centers as well as category-specific regions. Both the Inferior Frontal Gyrus (IFG) and ATL demonstrated a negative correlation with typicality, whereas inferior parietal regions showed positive effects. We interpret this in light of functional theories of these regions. Interactions between category and typicality were not observed in regions classically recognized as category-specific, thus, providing an argument against category specific regions, at least with fMRI

Is second best good enough? An EEG study on the effects of word expectancy in sentence comprehension

Sentence comprehension can be facilitated when readers anticipate the upcoming word. Notwithstanding, it remains uncertain if only the most expected word is anticipated, as postulated by the serial graded hypothesis, or if all probable words are pre-activated, as proposed by the parallel probabilistic hypothesis. To test these contrasting accounts, we compared the processing of expected and unexpected words with second-best words, i.e. the second most expected word in a sentence. The results, from 30 participants, revealed a graded facilitation effect for the expected words, indexed by the N400 mean amplitude, which was the least negative for the most expected words, intermediate for second-best words, and most negative for unexpected words. The Post-N400 Positivity analysis did not reveal any significant effects. The facilitation effect found for the most expected and second-best words suggests that readers can pre-activate multiple candidates during sentence comprehension

Cardiac Doppler Variation with Volume Status Changes in General Intensive Care

Num grupo de 64 doentes de uma Unidade de Cuidados Intensivos, 24 dos quais submetidos a ventilação mecânica, foi determinada a influência da modificação da volémia nas características do Doppler cardíaco, através da negativização do balanço hídrico e correspondente modificação da pressão venosa central. Com a modificação da volémia, a relação E/A do fluxo transvalvular mitral mostrou uma tendência para reduzir, o tempo de desaceleração da onda E mitral para diminuir, o tempo de relaxamento isovolumétrico para aumentar, e a veia cava inferior reduziu o seu diâmetro expiratório e aumentou o valor do colapso inspiratório. Não se observou uma correlação significativa entre os valores das variáveis estudadas e a modificação da volémia, inclusivamente entre a pressão venosa central e o balanço hídrico. A modificação da volémia em doentes críticos modifica as características de determinados parâmetros de ecocardiografia- -Doppler, mas não é possível predizer a magnitude dessa variação

Substrato para acondicionamento de estacas porta-borbulhas de cupuaçu - Theobroma grandiflorum (Spreng) Schum.

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In situ photobiology of corals over large depth ranges: A multivariate analysis on the roles of environment, host, and algal symbiont

We applied a multivariate analysis to investigate the roles of host and symbiont on the in situ physiological response of genus Madracis holobionts towards light. Across a large depth gradient (5–40 m) and for four Madracis species and three symbiont genotypes, we assessed several variables by measuring chlorophyll a fluorescence, photosynthetic pigment composition, or symbiont population descriptors. Most of the variation is explained by two major photobiological components: light-use efficiency and symbiont cell densities. Two other minor components emphasize photoprotective pathways and light-harvesting properties such as secondary pigments. Statistics highlight the role of irradiance on coral physiology and reveal mechanisms that are either genetically constrained, such as symbiont cell sizes, or environmentally dependent, such as photochemical efficiencies. Other parameters, such as cellular light-harvesting and photoprotective pigment concentrations, are regulated by host, symbiont, and environment. The interaction between host and environment stresses the role of host properties in adjusting the internal environment available for the endosymbionts. Different holobiont strategies, relating to symbiont cell density, vary in their physiological optimization of light-harvesting or photoprotective mechanisms and link to host-species distribution and dominance over the reef slope. Symbiont functional diversity appears to have a significant role but does not explain host vertical distribution patterns per se, highlighting the importance of species-specific morphological and physiological properties of the coral host

Microbial indicators of environmental perturbations in coral reef ecosystems

Background Coral reefs are facing unprecedented pressure on local and global scales. Sensitive and rapid markers for ecosystem stress are urgently needed to underpin effective management and restoration strategies. Although the fundamental contribution of microbes to the stability and functioning of coral reefs is widely recognised, it remains unclear how different reef microbiomes respond to environmental perturbations and whether microbiomes are sensitive enough to predict environmental anomalies that can lead to ecosystem stress. However, the lack of coral reef microbial baselines hinders our ability to study the link between shifts in microbiomes and ecosystem stress. In this study, we established a comprehensive microbial reference database for selected Great Barrier Reef sites to assess the diagnostic value of multiple free-living and host-associated reef microbiomes to infer the environmental state of coral reef ecosystems. Results A comprehensive microbial reference database, originating from multiple coral reef microbiomes (i.e. seawater, sediment, corals, sponges and macroalgae), was generated by 16S rRNA gene sequencing for 381 samples collected over the course of 16 months. By coupling this database to environmental parameters, we showed that the seawater microbiome has the greatest diagnostic value to infer shifts in the surrounding reef environment. In fact, 56% of the observed compositional variation in the microbiome was explained by environmental parameters, and temporal successions in the seawater microbiome were characterised by uniform community assembly patterns. Host-associated microbiomes, in contrast, were five-times less responsive to the environment and their community assembly patterns were generally less uniform. By applying a suite of indicator value and machine learning approaches, we further showed that seawater microbial community data provide an accurate prediction of temperature and eutrophication state (i.e. chlorophyll concentration and turbidity). Conclusion Our results reveal that free-living microbial communities have a high potential to infer environmental parameters due to their environmental sensitivity and predictability. This highlights the diagnostic value of microorganisms and illustrates how long-term coral reef monitoring initiatives could be enhanced by incorporating assessments of microbial communities in seawater. We therefore recommend timely integration of microbial sampling into current coral reef monitoring initiatives.We would like to acknowledge the contribution of the Marine Microbes(MM) and Biomes of Australian Soil Environments (BASE) projects, throughthe Australian Microbiome Initiative in the generation of data used in thispublication. The Australian Microbiome Initiative is supported by fundingfrom Bioplatforms Australia through the Australian Government NationalCollaborative Research Infrastructure Strategy (NCRIS). The study was furtherfunded by the Advance Queensland PhD Scholarship, the Great Barrier ReefMarine Park Authority Management Award and a National EnvironmentalScience Program (NESP) grant awarded to BG.The funders had no role in the study design, data collection and analysis,decision to publish, or preparation of the manuscript.info:eu-repo/semantics/publishedVersio