The effect of ocean acidification on plant-animal interactions in a <i>Posidonia oceanica</i> meadow

Ocean acidification may be one of the greatest challenges facing 'Society over the next SO- 100 years. In the Mediterranean Sea, meadows of the seagrass Posidonia oceanica play a pivotal role in coastal systems, providing shelter and food for a highly diversified plant and animal community, and nursery for several commercial species of fish and bivalves. This thesis aims to provide a broad overview of the effect of acidification on P. oceanica, and its associated community, through observation of seagrass meadows associated with subtidal CO2 vents off the Castello Aragonese, Ischia, Italy. Control (mean pH 8.1) and acidified (mean pH 7.8) stations were situated in seagrass meadows on both the north and south side of the Castello Aragonese. Research was concentrated into three main objectives; to investigate the effect of acidification on 1) plant structure and function, 2) invertebrate community dynamics, and 3) macroherbivore grazing pressure. Results suggested that P. oceanica and its associated community should be robust to levels of acidification projected for the end of this century. Seagrass density, invertebrate abundance, and P. oceanica grazing pressure all increased in response to acidification. Although a slight decrease in invertebrate diversity was observed in 'acidified stations, species richness was maintained. Increased grazing by the fish Salpa salpa was most highly correlated to a decrease in epiphytic algal cover and C:N content of the [eaves, and an increase seagrass density. Whilst fish may select leaves with low algal cover and C:N content, previous research suggests that increased shoot density is a response to high grazing pressure. The abundance of many groups of invertebrate taxa was positively correlated to shoot density, whilst decapods decreased during months of reduced canopy height, suggesting changes in P. oceanica condition variables, in response to acidification, may lead to a cascade of indirect effects which have positive or negative influences on the abundance of the associated invertebrate community. One of the most striking findings of this thesis was the ability of calcifying species to persevere, and even flourish in acidified conditions. This may be due to the complex nature of the seagrass, and high levels of photosynthesis, leading to local maintenance of pH microclimates. Secondly, the high degree of pH variability that naturally occurs in these shallow water habitats may result in organisms that are be better equipped to withstand pH variation. This research suggests that highly productive, non-calcifying, biogenic habitats, such as seagrass beds, may provide a refuge from OA, and highlights the importance of their conservation

Integrating methods for ecosystem service assessment and valuation: Mixed methods or mixed messages?

A mixed-method approach was used to assess and value the ecosystem services derived from the Dogger Bank, an extensive shallow sandbank in the southern North Sea. Three parallel studies were undertaken that 1) identified and quantified, where possible, how indicators for ecosystem service provision may change according to two future scenarios, 2) assessed members of the public's willingness-to-pay for improvements to a small number of ecosystem services as a consequence of a hypothetical management plan, and 3) facilitated a process of deliberation that allowed members of the public to explore the uses of the Dogger Bank and the conflicts and dilemmas involved in its management. Each of these studies was designed to answer different and specific research questions and therefore contributes different insights about the ecosystem services delivered by the Dogger Bank. This paper explores what can be gained by bringing these findings together post hoc and the extent to which the different methods are complementary. Findings suggest that mixed-method research brings more understanding than can be gained from the individual approaches alone. Nevertheless, the choice of methods used and how these methods are implemented strongly affects the results obtained

Effect of Hydrocortisone on Mortality and Organ Support in Patients With Severe COVID-19: The REMAP-CAP COVID-19 Corticosteroid Domain Randomized Clinical Trial.

Importance: Evidence regarding corticosteroid use for severe coronavirus disease 2019 (COVID-19) is limited. Objective: To determine whether hydrocortisone improves outcome for patients with severe COVID-19. Design, Setting, and Participants: An ongoing adaptive platform trial testing multiple interventions within multiple therapeutic domains, for example, antiviral agents, corticosteroids, or immunoglobulin. Between March 9 and June 17, 2020, 614 adult patients with suspected or confirmed COVID-19 were enrolled and randomized within at least 1 domain following admission to an intensive care unit (ICU) for respiratory or cardiovascular organ support at 121 sites in 8 countries. Of these, 403 were randomized to open-label interventions within the corticosteroid domain. The domain was halted after results from another trial were released. Follow-up ended August 12, 2020. Interventions: The corticosteroid domain randomized participants to a fixed 7-day course of intravenous hydrocortisone (50 mg or 100 mg every 6 hours) (n = 143), a shock-dependent course (50 mg every 6 hours when shock was clinically evident) (n = 152), or no hydrocortisone (n = 108). Main Outcomes and Measures: The primary end point was organ support-free days (days alive and free of ICU-based respiratory or cardiovascular support) within 21 days, where patients who died were assigned -1 day. The primary analysis was a bayesian cumulative logistic model that included all patients enrolled with severe COVID-19, adjusting for age, sex, site, region, time, assignment to interventions within other domains, and domain and intervention eligibility. Superiority was defined as the posterior probability of an odds ratio greater than 1 (threshold for trial conclusion of superiority >99%). Results: After excluding 19 participants who withdrew consent, there were 384 patients (mean age, 60 years; 29% female) randomized to the fixed-dose (n = 137), shock-dependent (n = 146), and no (n = 101) hydrocortisone groups; 379 (99%) completed the study and were included in the analysis. The mean age for the 3 groups ranged between 59.5 and 60.4 years; most patients were male (range, 70.6%-71.5%); mean body mass index ranged between 29.7 and 30.9; and patients receiving mechanical ventilation ranged between 50.0% and 63.5%. For the fixed-dose, shock-dependent, and no hydrocortisone groups, respectively, the median organ support-free days were 0 (IQR, -1 to 15), 0 (IQR, -1 to 13), and 0 (-1 to 11) days (composed of 30%, 26%, and 33% mortality rates and 11.5, 9.5, and 6 median organ support-free days among survivors). The median adjusted odds ratio and bayesian probability of superiority were 1.43 (95% credible interval, 0.91-2.27) and 93% for fixed-dose hydrocortisone, respectively, and were 1.22 (95% credible interval, 0.76-1.94) and 80% for shock-dependent hydrocortisone compared with no hydrocortisone. Serious adverse events were reported in 4 (3%), 5 (3%), and 1 (1%) patients in the fixed-dose, shock-dependent, and no hydrocortisone groups, respectively. Conclusions and Relevance: Among patients with severe COVID-19, treatment with a 7-day fixed-dose course of hydrocortisone or shock-dependent dosing of hydrocortisone, compared with no hydrocortisone, resulted in 93% and 80% probabilities of superiority with regard to the odds of improvement in organ support-free days within 21 days. However, the trial was stopped early and no treatment strategy met prespecified criteria for statistical superiority, precluding definitive conclusions. Trial Registration: ClinicalTrials.gov Identifier: NCT02735707

Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19

IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19. Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19. DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022). INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days. MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes. RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively). CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570

Assessment of the Threat of Toxic Microalgal Species to the Great Barrier Reef World Heritage Area: a literature review

[Extract] Prerequisites for the assessment of the threat of introduced and invasive marine pests to a particular ecosystem are knowledge of species present, their current distributions and abundances. This information, however, largely does not exist for microalgal communities in the Great Barrier Reef World Heritage Area (GBRWHA). The need for such baseline information was recognised by the Australian Ballast Water Management Advisory Council, the Standing Committee on Agriculture and Resource Management, and the Australian and New Zealand Environment and Conservation Council. In recognition of these problems, baseline studies through port surveys have been conducted in Australia to define the state of introductions and occurrences of non-indigenous species. These efforts were coordinated largely by the CSIRO Centre for Research on Introduced Marine Species and also involved several State agencies and research organisations

Interaction Before Agriculture:Exchanging Material and Sharing Knowledge in the Final Pleistocene Levant

This article discusses social interaction in the Epipalaeolithic of southwest Asia. Discussions of contact, social relationships and social organization have primarily focused on the Pre-Pottery Neolithic and are often considered to represent typical hallmarks of emergent farming societies. The hunter-gatherers of the final Pleistocene, in particular those of the Early and Middle Epipalaeolithic, have more rarely been the focus of such discussions. In this article we consider evidence for interaction from the Azraq Basin of eastern Jordan, to question the uniqueness of the Neolithic evidence for interaction. We argue that interaction between differently-constituted groups can be traced within the Early Epipalaeolithic of the southern Levant, suggesting that it is of far greater antiquity than previously considered

Indirect effects may buffer negative responses of seagrass invertebrate communities to ocean acidification

Ocean acidification has been shown to have highly variable effects, with many negative and some positive responses from individual species, while community level effects are largely unknown. Although an overall loss of biodiversity is expected, predicting the effects of ocean acidification on whole assemblages can be problematic as both direct and indirect effects of acidification must be taken into consideration. This study demonstrates how invertebrate assemblages associated with the highly productive seagrass, Posidonia oceanica, respond to natural acidification that occurs at CO2 vents off the coast of Italy. We examined seasonal differences in invertebrate community structure between two distinct pH zones: control (pH 8.1) and acidified (pH 7.8) and show that many groups of invertebrate taxa were robust to acidification effects. Differences in community struc- ture appeared to be driven by the indirect effects of acidification, such as changes to canopy structure and food availability, rather than physiological intolerance to low pH. The number of invertebrates collected in acidified stations was almost double that of control stations during the study and many heavily calcified species appeared to thrive. These results highlight how positive indirect effects may buffer the ecological impacts of acidification, and provide evidence that this highly productive, nearshore habitat may provide refuge to its associated commu- nities from future ocean acidification

Integrating methods for ecosystem service assessment and valuation: Mixed methods or mixed messages?

A mixed-method approach was used to assess and value the ecosystem services derived from the Dogger Bank, an extensive shallow sandbank in the southern North Sea. Three parallel studies were undertaken that 1) identified and quantified, where possible, how indicators for ecosystem service provision may change according to two future scenarios, 2) assessed members of the public's willingness-to-pay for improvements to a small number of ecosystem services as a consequence of a hypothetical management plan, and 3) facilitated a process of deliberation that allowed members of the public to explore the uses of the Dogger Bank and the conflicts and dilemmas involved in its management. Each of these studies was designed to answer different and specific research questions and therefore contributes different insights about the ecosystem services delivered by the Dogger Bank. This paper explores what can be gained by bringing these findings together post hoc and the extent to which the different methods are complementary. Findings suggest that mixed-method research brings more understanding than can be gained from the individual approaches alone. Nevertheless, the choice of methods used and how these methods are implemented strongly affects the results obtained