Knowledge of sediment erosion and deposition can be useful for a variety of engineering, marine science, and environmental applications, but collecting detailed time-series measurements of the sediment-water interface can be challenging, particularly in coastal marine environments. We developed economical and open-source sediment level loggers to record sediment-water interface time-series data with accuracy up to 1 cm. The logger is composed of a programmable Circuit-Python (or Arduino) microcontroller and "breakout boards" that attach to a specially designed printed circuit board (PCB) and an array of evenly spaced photoresistors enclosed in a robust waterproof housing.
View Article and Find Full Text PDFThe major ion chemistry of the ocean has been assumed to be controlled by river input, hydrothermal circulation at mid-ocean ridges, carbonate production, and low-temperature alteration of seafloor basalt, but marine chemical budgets remain difficult to balance. Here we propose that large-scale groundwater flow and diagenetic reactions in continental shelf sediments have been overlooked as an important contributor to major ion budgets in the ocean. Based on data synthesized from 17 passive margin basins, continental shelves contribute fluid exchanges comparable to hydrothermal circulation at mid-ocean ridges.
View Article and Find Full Text PDFCoastal mangrove swamps play an important role in nutrient cycling at the land-ocean boundary. However, little is known about the role of periodic seawater-groundwater exchange in the nitrogen cycling processes. Seawater-groundwater exchange rates and inorganic nitrogen concentrations were investigated along a shore-perpendicular intertidal transect in Daya Bay, China.
View Article and Find Full Text PDFSpiritual values and beliefs of patients and families influence resilience during chronic illness and shape patient choices during advance care planning. The spiritual needs of Baby Boomers will be more diverse than previous generations, in connection with the questioning, experimental mind-set of this group and the fact that it includes a higher proportion of immigrant populations outside the Judeo-Christian tradition. Social workers are trained explicitly to intervene with diverse populations and are well positioned to offer spiritual support in ways that do not necessarily conform to traditional religions.
View Article and Find Full Text PDFEcological zonation of salt marsh macrophytes is strongly influenced by hydrologic factors, but these factors are poorly understood. We examined groundwater flow patterns through surficial sediments in two saltmarshes in the southeastern United States to quantify hydrologic differences between distinct ecological zones. Both sites included tall- or medium-form Spartina alterniflora near the creek bank; short-form Spartina alterniflora in the mid-marsh; salt flats and Salicornia virginica in the high marsh; and Juncus roemarianus in brackish-to-fresh areas adjacent to uplands.
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