Results from a data acquisition system prototype project using a switch-based event builder

A prototype of a high bandwidth parallel event builder has been designed and tested. The architecture is based on a simple switching network and is adaptable to a wide variety of data acquisition systems. An eight channel system with a peak throughput of 160 Megabytes per second has been implemented. It is modularly expandable to 64 channels (over one Gigabyte per second). The prototype uses a number of relatively recent commercial technologies, including very high speed fiber-optic data links, high integration crossbar switches and embedded RISC processors. It is based on an open architecture which permits the installation of new technologies with little redesign effort. 5 refs., 6 figs

Platelet-Rich Plasma Promotes the Proliferation of Human Muscle Derived Progenitor Cells and Maintains Their Stemness

Human muscle-derived progenitor cells (hMDPCs) offer great promise for muscle cell-based regenerative medicine; however, prolonged ex-vivo expansion using animal sera is necessary to acquire sufficient cells for transplantation. Due to the risks associated with the use of animal sera, the development of a strategy for the ex vivo expansion of hMDPCs is required. The purpose of this study was to investigate the efficacy of using platelet-rich plasma (PRP) for the ex-vivo expansion of hMDPCs. Pre-plated MDPCs, myoendothelial cells, and pericytes are three populations of hMDPCs that we isolated by the modified pre-plate technique and Fluorescence Activated Cell Sorting (FACS), respectively. Pooled allogeneic human PRP was obtained from a local blood bank, and the effect that thrombin-activated PRP-releasate supplemented media had on the ex-vivo expansion of the hMDPCs was tested against FBS supplemented media, both in vitro and in vivo. PRP significantly enhanced short and long-term cell proliferation, with or without FBS supplementation. Antibody-neutralization of PDGF significantly blocked the mitogenic/proliferative effects that PRP had on the hMDPCs. A more stable and sustained expression of markers associated with stemness, and a decreased expression of lineage specific markers was observed in the PRP-expanded cells when compared with the FBS-expanded cells. The in vitro osteogenic, chondrogenic, and myogenic differentiation capacities of the hMDPCs were not altered when expanded in media supplemented with PRP. All populations of hMDPCs that were expanded in PRP supplemented media retained their ability to regenerate myofibers in vivo. Our data demonstrated that PRP promoted the proliferation and maintained the multi-differentiation capacities of the hMDPCs during ex-vivo expansion by maintaining the cells in an undifferentiated state. Moreover, PDGF appears to be a key contributing factor to the beneficial effect that PRP has on the proliferation of hMDPCs. © 2013 Li et al

Groundwater flow and salt transport in a subterranean estuary driven by intensified wave conditions

A numerical study, based on a density-dependent variably saturated groundwater flow model, was conducted to investigate flow and salt transport in a nearshore aquifer under intensified wave conditions caused by offshore storms. Temporally varying onshore hydraulic gradients due to wave setup were determined as the seaward boundary condition for the simulated aquifer. The results showed a rapid increase in influxes across the aquifer-ocean interface in response to the wave event followed by a more gradual increase in effluxes. The upper saline plume first widened horizontally as the wave setup point moved landward. It then expanded vertically with recirculating seawater pushed downward by the wave-induced hydraulic gradient. The time for the salt distribution to return to the prestorm condition was up to a hundred days and correlated strongly with the time for seawater to recirculate through the aquifer. The pathways of recirculating seawater and fresh groundwater were largely modified by the wave event. These pathways crossed through the same spatial locations at similar times, indicating significant salt-freshwater mixing. The flow and salt transport dynamics were more responsive to wave events of longer duration and higher intensity, especially in more permeable aquifers with lower fresh groundwater discharge. Despite their larger response, aquifers with higher permeability and beach slope recovered more rapidly postevent. The rapid recovery of the flows compared with the salinity distribution should be considered in field data interpretation. Due to their long-lasting impact, wave events may significantly influence the geochemical conditions and the fate of chemicals in a subterranean estuary. Key Points Intensified waves perturb flow and transport in a subterranean estuary Lengthy period (months) for salinity distribution to recover from a wave event Exchange fluxes and flows respond and recover rapidly following a wave even

The fresh water lens in a barrier beach.

Oceanic landmasses, under natural conditions commonly develop a body of fresh groundwater. This freshwater body assumes the form of a lens floating on the underlying seawater, and is usually thickest at the central part of the landmass tapering to a thin edge at the shore margins. With certain unique exceptions as will be described herein the flow moves from the thickest part of the lens outward and upward to the shoreline. The extent of a freshwater lens depends primarily on landmass width, permeability, rainfall, and tidal range. As a part of a general study of the freshwater lens phenomena, a field investigation was made at East Beach, the largest of the Rhode Island barrier beaches.(from paper

Preliminary hydrographic surveys of some ponds in the Pelican Cays, Belize, Central America

Hydrographic and hydrologic surveys of three ponds in the Pelican Cays Group were carried out using hand-held sonar, pressure transducer tide loggers, and YSI temperature-salinity probes. These ponds characteristically have a circular pattern with steeply sloping sides. The pond depths range from 4.6 m in a small pond with a diameter of 100 m to 15.2 m in a large pond with a diameter of 840 m; in general, depth increases with increasing pond size. Depths ranged from 15.2 m for a distance of 100 m between cays to 28.7 m for a distance of 1,150 m. Pond salinities averaged 35.3 ppt with a range of 1.5 ppt, and temperatures averaged 31.4°C with surface temperatures about 1°C higher than bottom temperatures

Asymmetric variation of Ghyben-Herzberg lens.

An asymmetric freshwater lens is shown to exist in a long narrow coastal barrier beach bounded on 1 side by a salt water lagoon and on the other by the ocean. Field measurements of ground-water specific conductance and water table elevations show the lens to average approximately 17 ft (5m) in maximum thickness and to be thicker on the side toward the lagoon. The asymmetry is apparently due to an effective mean sea level higher than actual mean sea level on the ocean side which occurs because of tide and wave action on a sloping ocean beach. -from ASCE Publications Abstract