82 research outputs found
Regulation of E-cadherin and Î’-catenin by Ca 2+ in colon carcinoma is dependent on calcium-sensing receptor expression and function
An siRNA directed against the extracellular calcium-sensing receptor (CaSR) was used to down-regulate this protein in CBS colon carcinoma cells. In additional studies, we utilized a variant of the parental CBS line that demonstrates CaSR expression but does not upregulate this protein in response to extracellular Ca 2+ . In neither the siRNA-transfected cells nor the Ca 2+ -nonresponsive variant cells did inclusion of Ca 2+ in the culture medium inhibit proliferation or induce morphological alterations. Extracellular Ca 2+ also failed to induce E-cadherin production or a shift in Β-catenin from the cytoplasm to the cell membrane. In mock-transfected cells and in a Ca 2+ -responsive variant line derived from the same parental CBS cells, Ca 2+ treatment resulted in growth-reduction. This was accompanied by increased E-cadherin production and a shift in Β-catenin distribution from the cytoplasm to the cell membrane. Additionally, down-regulation of c-myc and cyclin D1 expression was observed in mock-transfected cells and in the Ca 2+ -responsive variant line (along with reduced T cell factor transcriptional activation). Neither c-myc nor cyclin D1 was significantly down-regulated in the siRNA-transfected cells or in the Ca 2+ -nonresponsive variant cells upon Ca 2+ stimulation. In histological sections of human colon carcinoma CaSR was significantly reduced as compared to the level in normal colonic crypt epithelial cells. Where CaSR expression was high, strong surface staining for E-cadherin and Β-catenin was observed. Where CaSR expression was reduced, Β-catenin surface expression was likewise reduced. © 2007 Wiley-Liss, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/56113/1/22858_ftp.pd
Global distribution of the decay timescale of mixed layer inertial motions observed by satellite-tracked drifters
Author Posting. © American Geophysical Union, 2009. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 114 (2009): C11010, doi:10.1029/2008JC005216.The decay timescale of mixed layer inertial amplitudes has been estimated from satellite tracked drifter trajectories from 1990 to 2004 as the e-folding timescale of the temporal correlation functions. The decay timescales increase with latitude in all basins except the North Atlantic. A beta dispersion model shows that dephasing leads to meridional variations of the decay timescale in the North Pacific and the Southern Ocean, but meridional variations of the buoyancy structure in the North Atlantic act to compensate the beta effect, leading to a lack of meridional variation of the decay timescale in that ocean.Jong Jin Park was supported by a WHOI postdoctoral scholarship. Ray Schmitt acknowledges NSF grant OCE 84794900. This
study was partly supported by ‘‘A Study on the Monitoring of the Global
Ocean Variability with ARGO Program’’ in Meteorological Research
Institute/KMA
WHOI Hawaii Ocean Timeseries Station (WHOTS) : WHOTS-14 2017 mooring turnaround cruise report
The Woods Hole Oceanographic Institution (WHOI) Hawaii Ocean Time-series Station (WHOTS), located approximately 100 km north of Oahu, Hawaii, is intended to provide long-term, high-quality air-sea fluxes as a part of the NOAA Climate Observation Program. The WHOTS mooring also serves as a coordinated part of the Hawaii Ocean Time-series (HOT) program, contributing to the goals of observing heat, fresh water and chemical fluxes at a site representative of the oligotrophic North Pacific Ocean. The approach is to maintain a surface mooring instrumented for meteorological and oceanographic measurements at a site near
22.75°N, 158°W by successive mooring turnarounds. These observations are used to investigate
air–sea interaction processes related to climate variability.
This report documents recovery of the thirteenth WHOTS mooring (WHOTS-13) and deployment of the fourteenth mooring (WHOTS-14). Both moorings used Surlyn foam buoys as the surface element and were outfitted with two Air–Sea Interaction Meteorology (ASIMET) systems. Each ASIMET system measures, records, and transmits via Argos and Iridium satellite the surface meteorological variables necessary to compute air–sea fluxes of heat, moisture and momentum. The upper 155 m of the moorings were outfitted with oceanographic sensors for the measurement of temperature, conductivity and velocity in a cooperative effort with Dr. Roger Lukas of the University of Hawaii. A pCO2 system and ancillary sensors were installed on the
buoys in cooperation with Adrienne J. Sutton at the Pacific Marine Environmental Laboratory.
The WHOTS mooring turnaround was conducted on the NOAA ship Hi’ialakai (R/V HA). Operations were a joint effort undertaken by the Upper Ocean Processes group (UOP) of the Woods Hole Oceanographic Institution (WHOI), the University of Hawaii’s (UH) Hawaii Ocean Time-series group (HOT), and the able-bodied crew of R/V HA. The cruise took place between 25 July and August 3 2017. Operations began with deployment of the WHOTS-14 mooring on 27 July. This was followed by a period of intercomparison, where meteorological measurements and CTDs were collected at both the W13 and W14 stations. Recovery of the WHOTS-13 mooring took place on 31 July. This report details the in-port operations, pre-cruise buoy preparations, cruise operations and data collected.Funding was provided by the National Oceanic and Atmospheric Administration under Grant No. NA14OAR4320158 and the Cooperative Institute for the North Atlantic Region (CINAR)
Upregulation of calcium-sensing receptor and mitogen-activated protein kinase signalling in the regulation of growth and differentiation in colon carcinoma
In the present study, we demonstrate that Ca2+-induced growth inhibition and induction of differentiation in a line of human colon carcinoma cells (CBS) is dependent on mitogen-activated protein (MAP) kinase signaling and is associated with upregulation of extracellular calcium-sensing receptor (CaSR) expression. When CBS cells were grown in Ca2+-free medium and then switched to medium supplemented with 1.4 mM Ca2+, proliferation was reduced and morphologic features of differentiation were expressed. E-cadherin, which was minimally expressed in nonsupplemented medium, was rapidly induced in response to Ca2+ stimulation. Sustained activation of the extracellular signal-regulated kinase (ERK) occured in Ca2+-supplemented medium. When an inhibitor of ERK activation (10 μM U0126) was included in the Ca2+-supplemented culture medium, ERK-activation did not occur. Concomitantly, E-cadherin was not induced, cell proliferation remained high and differentiation was not observed. The same level of Ca2+ supplementation that induced MAP kinase activation also stimulated CaSR upregulation in CBS cells. A clonal isolate of the CBS line that did not upregulate CaSR expression in response to extracellular Ca2+ was isolated from the parent cells. This isolate failed to produce E-cadherin or undergo growth inhibition/induction of differentiation when exposed to Ca2+ in the culture medium. However, ERK-activation occurred as efficiently in this isolate as in parent CBS cells or in a cloned isolate that underwent growth reduction and differentiation in response to Ca2+ stimulation. Together, these data indicate that CaSR upregulation and MAP kinase signalling are both intermediates in the control of colon carcinoma cell growth and differentiation. They appear to function, at least in part, independently of one another
Phylogenetic structure of body shape in a diverse inland ichthyofauna
Abstract Body shape is a fundamental metric of animal diversity affecting critical behavioral and ecological dynamics and conservation status, yet previously available methods capture only a fraction of total body-shape variance. Here we use structure-from-motion (SFM) 3D photogrammetry to generate digital 3D models of adult fishes from the Lower Mississippi Basin, one of the most diverse temperate-zone freshwater faunas on Earth, and 3D geometric morphometrics to capture morphologically distinct shape variables, interpreting principal components as growth fields. The mean body shape in this fauna resembles plesiomorphic teleost fishes, and the major dimensions of body-shape disparity are similar to those of other fish faunas worldwide. Major patterns of body-shape disparity are structured by phylogeny, with nested clades occupying distinct portions of the morphospace, most of the morphospace occupied by multiple distinct clades, and one clade (Acanthomorpha) accounting for over half of the total body shape variance. In contrast to previous studies, variance in body depth (59.4%) structures overall body-shape disparity more than does length (31.1%), while width accounts for a non-trivial (9.5%) amount of the total body-shape disparity
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