Total ecosystem carbon stocks at the marine-terrestrial interface: Blue carbon of the Pacific Northwest Coast, United States.

The coastal ecosystems of temperate North America provide a variety of ecosystem services including high rates of carbon sequestration. Yet, little data exist for the carbon stocks of major tidal wetland types in the Pacific Northwest, United States. We quantified the total ecosystem carbon stocks (TECS) in seagrass, emergent marshes, and forested tidal wetlands, occurring along increasing elevation and decreasing salinity gradients. The TECS included the total aboveground carbon stocks and the entire soil profile (to as deep as 3 m). TECS significantly increased along the elevation and salinity gradients: 217 ± 60 Mg C/ha for seagrass (low elevation/high salinity), 417 ± 70 Mg C/ha for low marsh, 551 ± 47 Mg C/ha for high marsh, and 1,064 ± 38 Mg C/ha for tidal forest (high elevation/low salinity). Soil carbon stocks accounted for >98% of TECS in the seagrass and marsh communities and 78% in the tidal forest. Soils in the 0-100 cm portion of the profile accounted for only 48%-53% of the TECS in seagrasses and marshes and 34% of the TECS in tidal forests. Thus, the commonly applied limit defining TECS to a 100 cm depth would greatly underestimate both carbon stocks and potential greenhouse gas emissions from land-use conversion. The large carbon stocks coupled with other ecosystem services suggest value in the conservation and restoration of temperate zone tidal wetlands through climate change mitigation strategies. However, the findings suggest that long-term sea-level rise effects such as tidal inundation and increased porewater salinity will likely decrease ecosystem carbon stocks in the absence of upslope wetland migration buffer zones.

Comparison of three modalities of teleophthalmology delivery in regional Western Australia during the COVID-19 lock-down.

CLINICAL RELEVANCE: In conjunction with local optometry services, telehealth may be used in to provide specialist care for patients living in rural areas underserved by ophthalmology. BACKGROUND: To combat travel restrictions for specialist outreach to regional areas during the 2020 COVID-19 lockdown, Lions Outback Vision introduced three different modalities of teleophthalmology consultations; home-based telephone, hospital-based video, and optometry-based video. This study evaluated the utility of these in providing specialist care to rural patients during the pandemic. METHODS: Data from patients referred during the COVID-19 lock-down period (23 March 2020 to 5 June 2020) were analysed. If sufficient clinical information and imaging were available then ophthalmologists conducted home-based telephone consultations. If further ocular imaging or examination was required, then optometry-based video or hospital-based video were used. Data were analysed using ANOVA and two-sided t tests for continuous data and Chi Square statistics for categorical data (p < 0.05). RESULTS: Majority of the 431 consultations were conducted via home telephone (38%) or optometry-based video (37%). Indigenous patients (p = 0.014) and patients in very remote communities (p < 0.01) were more likely to receive a home-based telephone consultation. Because sufficient clinical information had already been obtained for home-based consultations, these patients were more likely to be booked for surgery than optometry (p < 0.01).Cataracts were the predominant diagnosis in optometry consults compared to hospital (p < 0.01). CONCLUSION: Primary optometry and home telephone represent a new modality for providing specialist care for patients living in very remote regions and for Indigenous patients. When appropriate clinical testing has been completed, telephone-based ophthalmology may continue to be useful for certain conditions such as waitlisting patients for cataract surgery and should continue to be funded beyond the duration of the pandemic for rural patients.

Conformational flexibility of EptA driven by an interdomain helix provides insights for enzyme-substrate recognition.

Many pathogenic gram-negative bacteria have developed mechanisms to increase resistance to cationic antimicrobial peptides by modifying the lipid A moiety. One modification is the addition of phospho-ethano-lamine to lipid A by the enzyme phospho-ethano-lamine transferase (EptA). Previously we reported the structure of EptA from Neisseria, revealing a two-domain architecture consisting of a periplasmic facing soluble domain and a transmembrane domain, linked together by a bridging helix. Here, the conformational flexibility of EptA in different detergent environments is probed by solution scattering and intrinsic fluorescence-quenching studies. The solution scattering studies reveal the enzyme in a more compact state with the two domains positioned close together in an n-do-decyl-ß-d-maltoside micelle environment and an open extended structure in an n-do-decyl-phospho-choline micelle environment. Intrinsic fluorescence quenching studies localize the domain movements to the bridging helix. These results provide important insights into substrate binding and the molecular mechanism of endotoxin modification by EptA.