Modeling organic carbon accumulation rates and residence times in coastal vegetated ecosystems

Coastal vegetated “blue carbon” ecosystems can store large quantities of organic carbon (OC) within their soils; however, the importance of these sinks for climate change mitigation depends on the OC accumulation rate (CAR) and residence time. Here we evaluate how two modeling approaches, a Bayesian age-depth model alone or in combination with a two-pool OC model, aid in our understanding of the time lines of OC within seagrass soils. Fitting these models to data from Posidonia oceanica soil cores, we show that age-depth models provided reasonable CAR estimates but resulted in a 22% higher estimation of OC burial rates when ephemeral rhizosphere OC was not subtracted. This illustrates the need to standardize CAR estimation to match the research target and time frames under consideration. Using a two-pool model in tandem with an age-depth model also yielded reasonable, albeit lower, CAR estimates with lower estimate uncertainty, which increased our ability to detect among-site differences and seascape-level trends. Moreover, the two-pool model provided several other useful soil OC diagnostics, including OC inputs, decay rates, and transit times. At our sites, soil OC decayed quite slowly both within fast cycling (0.028 ± 0.014 yr−1) and slow cycling (0.0007 ± 0.0003 yr−1) soil pools, resulting in OC taking between 146 and 825 yr to transit the soil system. Further, an estimated 85% to 93% of OC inputs enter slow-cycling soil pools, with transit times ranging from 891 to 3,115 yr, substantiating the importance of P. oceanica soils as natural, long-term OC sinks

Immunization with Cocktail of HIV-Derived Peptides in Montanide ISA-51 Is Immunogenic, but Causes Sterile Abscesses and Unacceptable Reactogenicity

BACKGROUND: A peptide vaccine was produced containing B and T cell epitopes from the V3 and C4 Envelope domains of 4 subtype B HIV-1 isolates (MN, RF, CanO, & Ev91). The peptide mixture was formulated as an emulsion in incomplete Freund's adjuvant (IFA). METHODS: Low-risk, healthy adult subjects were enrolled in a randomized, placebo-controlled dose-escalation study, and selected using criteria specifying that 50% in each study group would be HLA-B7+. Immunizations were scheduled at 0, 1, and 6 months using a total peptide dose of 1 or 4 mg. Adaptive immune responses in16 vaccine recipients and two placebo recipients after the 2nd immunization were evaluated using neutralization assays of sera, as well as ELISpot and ICS assays of cryopreserved PBMCs to assess CD4 and CD8 T-cell responses. In addition, (51)Cr release assays were performed on fresh PBMCs following 14-day stimulation with individual vaccine peptide antigens. RESULTS: 24 subjects were enrolled; 18 completed 2 injections. The study was prematurely terminated because 4 vaccinees developed prolonged pain and sterile abscess formation at the injection site-2 after dose 1, and 2 after dose 2. Two other subjects experienced severe systemic reactions consisting of headache, chills, nausea, and myalgia. Both reactions occurred after the second 4 mg dose. The immunogenicity assessments showed that 6/8 vaccinees at each dose level had detectable MN-specific neutralizing (NT) activity, and 2/7 HLA-B7+ vaccinees had classical CD8 CTL activity detected. However, using both ELISpot and ICS, 8/16 vaccinees (5/7 HLA-B7+) and 0/2 controls had detectable vaccine-specific CD8 T-cell responses. Subjects with moderate or severe systemic or local reactions tended to have more frequent T cell responses and higher antibody responses than those with mild or no reactions. CONCLUSIONS: The severity of local responses related to the formulation of these four peptides in IFA is clinically unacceptable for continued development. Both HIV-specific antibody and T cell responses were induced and the magnitude of response correlated with the severity of local and systemic reactions. If potent adjuvants are necessary for subunit vaccines to induce broad and durable immune responses, careful, incremental clinical evaluation is warranted to minimize the risk of adverse events. TRIAL REGISTRATION: ClinicalTrials.gov NCT00000886

Conserving Coastal Wetlands Despite Sea Level Rise

Coastal wetlands provide valuable services such as flood protection and fisheries production to a global population that is increasingly concentrated near the coast and dependent on its resources. Many of the world\u27s coastal wetlands suffered significant losses during this century, and the creation of new wetland areas is not keeping pace with recent losses. Some destruction of wetland areas can be expected as a consequence of the continual reworking of the coastal zone by dynamic geologic processes. Yet human activities also play a role, both directly by encroaching on coastal wetlands and indirectly by influencing the hydrologic and geologic processes in the coastal zone

Global dataset of soil organic carbon in tidal marshes.

Tidal marshes store large amounts of organic carbon in their soils. Field data quantifying soil organic carbon (SOC) stocks provide an important resource for researchers, natural resource managers, and policy-makers working towards the protection, restoration, and valuation of these ecosystems. We collated a global dataset of tidal marsh soil organic carbon (MarSOC) from 99 studies that includes location, soil depth, site name, dry bulk density, SOC, and/or soil organic matter (SOM). The MarSOC dataset includes 17,454 data points from 2,329 unique locations, and 29 countries. We generated a general transfer function for the conversion of SOM to SOC. Using this data we estimated a median (± median absolute deviation) value of 79.2 ± 38.1 Mg SOC ha-1 in the top 30 cm and 231 ± 134 Mg SOC ha-1 in the top 1 m of tidal marsh soils globally. This data can serve as a basis for future work, and may contribute to incorporation of tidal marsh ecosystems into climate change mitigation and adaptation strategies and policies

Global dataset of soil organic carbon in tidal marshes

Tidal marshes store large amounts of organic carbon in their soils. Field data quantifying soil organic carbon (SOC) stocks provide an important resource for researchers, natural resource managers, and policy-makers working towards the protection, restoration, and valuation of these ecosystems. We collated a global dataset of tidal marsh soil organic carbon (MarSOC) from 99 studies that includes location, soil depth, site name, dry bulk density, SOC, and/or soil organic matter (SOM). The MarSOC dataset includes 17,454 data points from 2,329 unique locations, and 29 countries. We generated a general transfer function for the conversion of SOM to SOC. Using this data we estimated a median (± median absolute deviation) value of 79.2 ± 38.1 Mg SOC ha−1 in the top 30 cm and 231 ± 134 Mg SOC ha−1 in the top 1 m of tidal marsh soils globally. This data can serve as a basis for future work, and may contribute to incorporation of tidal marsh ecosystems into climate change mitigation and adaptation strategies and policies

Communication Style And The Mangerial Effectiveness Of Male And Female Supervisors

This study examined whether a male-oriented management model is changing to a more flexible "feminine" style.  Males had more relaxed, friendly, impression leaving communication styles and were perceived as more effective managers

Detection of mucosal antibodies in HIV type 1-infected individuals

HIV-1-specific mucosal IgA antibodies may correlate with protection in highly exposed but uninfected individuals, but have been detected at highly variable levels in HIV-1-infected individuals. To determine the best assays for detection of IgA antibodies in mucosal samples, rectal washes from 16 HIV-1-infected and 14 uninfected individuals were distributed to six laboratories experienced in detection of mucosal antibodies. Assays for HIV-1-specific IgA and IgG were performed in a blinded fashion by each of the laboratories using modifications of ELISA and chemiluminescence-enhanced Western blotting. Rectal washes contained easily detectable total IgA levels that did not differ between HIV-1-infected and uninfected groups. Irrespective of the assay used, HIV-1-specific IgA antibodies were absent in most samples; only one laboratory identified a higher frequency of positive samples from HIV-1-infected than uninfected individuals. In spite of 10-fold lower levels of total IgG than IgA, all but one laboratory identified HIV-1-specific IgG in most rectal washes of HIV-1-infected individuals. Comparable and readily detectable levels of influenza-specific IgA antibodies were present in nasal, salivary, and rectal secretions from both HIV-1-infected and uninfected individuals. These observations suggest a selective alteration in the production of HIV-1-specific IgA antibodies in HIV-1-infected individuals