Recent Nitrogen Storage and Accumulation Rates in Mangrove Soils Exceed Historic Rates in the Urbanized San Juan Bay Estuary (Puerto Rico, United States).

Tropical mangrove forests have been described as "coastal kidneys," promoting sediment deposition and filtering contaminants, including excess nutrients. Coastal areas throughout the world are experiencing increased human activities, resulting in altered geomorphology, hydrology, and nutrient inputs. To effectively manage and sustain coastal mangroves, it is important to understand nitrogen (N) storage and accumulation in systems where human activities are causing rapid changes in N inputs and cycling. We examined N storage and accumulation rates in recent (1970 - 2016) and historic (1930 - 1970) decades in the context of urbanization in the San Juan Bay Estuary (SJBE, Puerto Rico), using mangrove soil cores that were radiometrically dated. Local anthropogenic stressors can alter N storage rates in peri-urban mangrove systems either directly by increasing N soil fertility or indirectly by altering hydrology (e.g., dredging, filling, and canalization). Nitrogen accumulation rates were greater in recent decades than historic decades at Piñones Forest and Martin Peña East. Martin Peña East was characterized by high urbanization, and Piñones, by the least urbanization in the SJBE. The mangrove forest at Martin Peña East fringed a poorly drained canal and often received raw sewage inputs, with N accumulation rates ranging from 17.7 to 37.9 g -2 y-1 in recent decades. The Piñones Forest was isolated and had low flushing, possibly exacerbated by river damming, with N accumulation rates ranging from 18.6 to 24.2 g -2 y-1 in recent decades. Nearly all (96.3%) of the estuary-wide mangrove N (9.4 Mg ha-1) was stored in the soils with 7.1 Mg ha-1 sequestered during 1970-2017 (0-18 cm) and 2.3 Mg ha-1 during 1930-1970 (19-28 cm). Estuary-wide mangrove soil N accumulation rates were over twice as great in recent decades (0.18 ± 0.002 Mg ha-1y-1) than historically (0.08 ± 0.001 Mg ha-1y-1). Nitrogen accumulation rates in SJBE mangrove soils in recent times were twofold larger than the rate of human-consumed food N that is exported as wastewater (0.08 Mg ha-1 y-1), suggesting the potential for mangroves to sequester human-derived N. Conservation and effective management of mangrove forests and their surrounding watersheds in the Anthropocene are important for maintaining water quality in coastal communities throughout tropical regions.

Recent Carbon Storage and Burial Exceed Historic Rates in the San Juan Bay Estuary Peri-Urban Mangrove Forests (Puerto Rico, United States).

Mangroves sequester significant quantities of organic carbon (C) because of high rates of burial in the soil and storage in biomass. We estimated mangrove forest C storage and accumulation rates in aboveground and belowground components among five sites along an urbanization gradient in the San Juan Bay Estuary, Puerto Rico. Sites included the highly urbanized and clogged Caño Martin Peña in the western half of the estuary, a series of lagoons in the center of the estuary, and a tropical forest reserve (Piñones) in the easternmost part. Radiometrically dated cores were used to determine sediment accretion and soil C storage and burial rates. Measurements of tree dendrometers coupled with allometric equations were used to estimate aboveground biomass. Estuary-wide mangrove forest C storage and accumulation rates were estimated using interpolation methods and coastal vegetation cover data. In recent decades (1970-2016), the highly urbanized Martin Peña East (MPE) site with low flushing had the highest C storage and burial rates among sites. The MPE soil carbon burial rate was over twice as great as global estimates. Mangrove forest C burial rates in recent decades were significantly greater than historic decades (1930-1970) at Cañno Martin Peña and Piñones. Although MPE and Piñones had similarly low flushing, the landscape settings (clogged canal vs forest reserve) and urbanization (high vs low) were different. Apparently, not only urbanization, but site-specific flushing patterns, landscape setting, and soil fertility affected soil C storage and burial rates. There was no difference in C burial rates between historic and recent decades at the San José and La Torrecilla lagoons. Mangrove forests had soil C burial rates ranging from 88 g m-2 y-1 at the San José lagoon to 469 g m-2 y-1 at the MPE in recent decades. Watershed anthropogenic CO2 emissions (1.56 million Mg C y-1) far exceeded the annual mangrove forest C storage rates (aboveground biomass plus soils: 17,713 Mg C y-1). A combination of maintaining healthy mangrove forests and reducing anthropogenic emissions might be necessary to mitigate greenhouse gas emissions in urban, tropical areas.

Does Earlier Cannulation With Veno-Venous Extracorporeal Membrane Oxygenation in Adult Patients With Acute Respiratory Distress Syndrome Decrease Duration of Artificial Mechanical Ventilation?

BACKGROUND: Acute respiratory distress syndrome (ARDS) is characterized by an acute, diffuse, inflammatory lung injury, leading to increased alveolar capillary permeability, increased lung weight, and loss of aerated lung tissue (Fan, Brodie, & Slutsky, 2018). Primary treatment for ARDS is artificial mechanical ventilation (AMV) (Wu, Huang, Wu, Wang, & Lin, 2016). Given recent advances in technology, the use of veno-venous extracorporeal membrane oxygenation (VV-ECMO) to treat severe ARDS is growing rapidly (Combes et al., 2014). OBJECTIVE: This 49-month quantitative, retrospective inpatient EMR chart review compared if cannulation with VV-ECMO up to and including 48 hours of admission and diagnosis in adult patients 30 to 65 years of age diagnosed with ARDS, decreased duration on AMV, as compared to participants who were cannulated after 48 hours of admission and diagnosis with ARDS. METHODS: A total of 110 participants were identified as receiving VV-ECMO during the study timeframe. Of the 58 participants who met all inclusion criteria, 39 participants were cannulated for VV-ECMO within 48 hours of admission and diagnosis with ARDS, and 19 participants were cannulated with VV-ECMO after 48 hours of admission and diagnosis with ARDS. RESULTS: Data collected identified no statistically significant (p < 0.579) difference in length of days on AMV between participant groups. CONCLUSIONS: Further studies are needed to determine if earlier initiation of VV-ECMO in adult patients with ARDS decrease time on AMV. IMPLICATIONS FOR NURSING: Although the results related to length of time on AMV did not produce statistical significance, the decreased duration of AMV in the participants who were cannulated within 48 hours (21 days vs. 27 days) may support several benefits associated with this participant population including increased knowledge of healthcare providers, decreased lung injury, earlier discharge which decreases hospital and patient cost, ability for patients to communicate sooner, decreased risk of pulmonary infection, decreased length of stay, decreased cost, and improved patient and family satisfaction.

Familial abnormalities of suppressor-cell function in systemic lupus erythematosus

We tested the hypothesis that abnormalities of central immune function are genetically controlled in patients with systemic lupus erythematosus. We used an in vitro suppressor-cell assay to evaluate central immunoregulation in 15 patients, 50 of their clinically healthy family members and 41 normal persons. Impaired suppressor-cell function was found in 11 patients; there was no correlation between disease activity and test results. Abnormal suppressor-cell activity was also found in 13 first-degree relatives, 12 of whom were women. We found no correlation between results of the suppressor-cell assay and the presence or absence of lymphocytotoxic antibodies in the relatives. Impaired suppressor-cell function cannot by itself explain the pathogenesis of systemic lupus erythematosus. Our results support the hypothesis that certain abnormalities of suppressor cells are genetic markers. We propose that the development of systemic lupus erythematosus requires the participation of at least two functionally distinct classes of genes.