1,489 research outputs found
Baltimore Harbor and channels aquatic benthos investigations : final technical report
This report describes work performed by the Virginia Institute of Marine Science, School of Marine Science of the College of William and Mary, Gloucester Point, VA, to document the existing preoperational conditions at four locations in the Chesapeake Bay selected as possible dredged material disposal areas for the deepening of the Baltimore Channel. The work was sponsored by the Baltimore District Corps of Engineers.
The objectives of this work were at each of the four potential disposal sites:
1 -document the surface (0-15 em) sediment conditions spatially and temporally
2 - document macrobenthic communities spatially and temporally.
3 - empty the REMOTS sediment profile camera to document visible vertical sediment structure
Final Report to the Coastal Erosion Abatement Commission, Commonwealth of Virginia concerning the inventory of sand supplies in the southern Chesapeake Bay
This final report to the Coastal Erosion Abatement Commission concerning the inventory of sand supplies in the southern portion of Chesapeake Bay is a continuation of the work reported on in September 1981 (Byrne et al). The report includes technical appendices in addition to the general text
Report to the Coastal Erosion Abatement Commission Commonwealth of Virginia concerning the Inventory of Sand Supplies in the Southern Chesapeake Bay
In its report to the Governor and the General Assembly of Virginia (Senate Document No. 4, Commonwealth of Virginia, 1979), the Coastal Erosion Abatement Commission found that there is a need to locate sources of sand supplies for rebuilding public beaches. Certain bottom areas in the lower Chesapeake Bay should be studied as possible sources of sand supply for public beaches. And toward that end, the Commission recommended that The School of Marine Science, Virginia Institute of Marine Science, College of William and Mary, study and analyze possible sources of sand supply in the lower Chesapeake Bay and vicinity for rebuilding public beaches.
This report describes the investigations undertaken during the first year of the appropriation, July 1980 through June 1981
Preliminary assessment of beaches and offshore sand resources of St. Eustatius, Netherlands Antilles : a report to the Government of St. Eustatius
Objectives: A pilot study was undertaken in July 1988 to: 1. Provide an estimate of the location and size of offshore sand resources suitable for beach nourishment. 2. Perform beach surveys and associated sampling for determining beach equilibrium configurations. 3. Provide a preliminary assessment of sites suitable for beach enhancement. 4. Provide a preliminary assessment of areas having extraordinary environmental sensitivity. Emphasis was given.to Oranje Baai and adjoining regions
Purification and Characterization of meta-Cresol Purple for Spectrophotometric Seawater pH Measurements
Spectrophotometric procedures allow rapid and precise measurements of the pH of natural waters. However, impurities in the acidâbase indicators used in these analyses can significantly affect measurement accuracy. This work describes HPLC procedures for purifying one such indicator, meta-cresol purple (mCP), and reports mCP physicalâchemical characteristics (thermodynamic equilibrium constants and visible-light absorbances) over a range of temperature (T) and salinity (S). Using pure mCP, seawater pH on the total hydrogen ion concentration scale (pHT) can be expressed in terms of measured mCP absorbance ratios (R = λ2A/λ1A) as follows:where âlog(K2Te2) = a + (b/T) + c ln T â dT; a = â246.64209 + 0.315971S + 2.8855 Ă 10â4S2; b = 7229.23864 â 7.098137S â 0.057034S2; c = 44.493382 â 0.052711S; d = 0.0781344; and mCP molar absorbance ratios (ei) are expressed as e1 = â0.007762 + 4.5174 Ă 10â5T and e3/e2 = â0.020813 + 2.60262 Ă 10â4T + 1.0436 Ă 10â4 (S â 35). The mCP absorbances, λ1A and λ2A, used to calculate R are measured at wavelengths (λ) of 434 and 578 nm. This characterization is appropriate for 278.15 †T †308.15 and 20 †S †40
The DNA repair component Metnase regulates Chk1 stability
Chk1 both arrests replication forks and enhances repair of DNA damage by phosphorylation of downstream effectors. Metnase (also termed SETMAR) is a SET histone methylase and transposase nuclease protein that promotes both DNA double strand break (DSB) repair and re-start of stalled replication forks. We previously found that Chk1 phosphorylation of Metnase on S495 enhanced its DNA DSB repair activity but decreased its ability to re-start stalled replication forks. Here we show that phosphorylated Metnase feeds back to increase the half-life of Chk1. Chk1 half-life is regulated by DDB1 targeting it to Cul4A for ubiquitination and destruction. Metnase decreases Chk1 interaction with DDB1, and decreases Chk1 ubiquitination. These data define a novel pathway for Chk1 regulation, whereby a target of Chk1, Metnase, feeds back to amplify Chk1 stability, and therefore enhance replication fork arrest
Mathematical analysis of a model for the growth of the bovine corpus luteum.
The corpus luteum (CL) is an ovarian tissue that grows in the wound space created by follicular rupture. It produces the progesterone needed in the uterus to maintain pregnancy. Rapid growth of the CL and progesterone transport to the uterus require angiogenesis, the creation of new blood vessels from pre-existing ones, a process which is regulated by proteins that include fibroblast growth factor 2 (FGF2). In this paper we develop a system of time-dependent ordinary differential equations to model CL growth. The dependent variables represent FGF2, endothelial cells (ECs), luteal cells, and stromal cells (like pericytes), by assuming that the CL volume is a continuum of the three cell types. We assume that if the CL volume exceeds that of the ovulated follicle, then growth is inhibited. This threshold volume partitions the system dynamics into two regimes, so that the model may be classified as a Filippov (piecewise smooth) system. We show that normal CL growth requires an appropriate balance between the growth rates of luteal and stromal cells. We investigate how angiogenesis influences CL growth by considering how the system dynamics depend on the dimensionless EC proliferation rate, Ïâ
. We find that weak (low Ïâ
) or strong (high Ïâ
) angiogenesis leads to 'pathological' CL growth, since the loss of CL constituents compromises progesterone production or delivery. However, for intermediate values of Ïâ
, normal CL growth is predicted. The implications of these results for cow fertility are also discussed. For example, inadequate angiogenesis has been linked to infertility in dairy cows
Fibroblast growth factor homologous factor 1 interacts with NEMO to regulate NF-ÎșB signaling in neurons.
Neuronal survival and plasticity critically depend on constitutive activity of the transcription factor nuclear factor-ÎșB (NF-ÎșB). We here describe a role for a small intracellular fibroblast growth factor homologue, the fibroblast growth factor homologous factor 1 (FHF1/FGF12), in the regulation of NF-ÎșB activity in mature neurons. FHFs have previously been described to control neuronal excitability, and mutations in FHF isoforms give rise to a form of progressive spinocerebellar ataxia. Using a protein-array approach, we identified FHF1b as a novel interactor of the canonical NF-ÎșB modulator IKKÎł/NEMO. Co-immunoprecipitation, pull-down and GAL4-reporter experiments, as well as proximity ligation assays, confirmed the interaction of FHF1 and NEMO and demonstrated that a major site of interaction occurred within the axon initial segment. Fhf1 gene silencing strongly activated neuronal NF-ÎșB activity and increased neurite lengths, branching patterns and spine counts in mature cortical neurons. The effects of FHF1 on neuronal NF-ÎșB activity and morphology required the presence of NEMO. Our results imply that FHF1 negatively regulates the constitutive NF-ÎșB activity in neurons
Impact of Coronary Anatomy and Stenting Technique on Long-Term Outcome After Drug-Eluting Stent Implantation for Unprotected Left Main Coronary Artery Disease
ObjectivesThis study sought to evaluate the impact of anatomic and procedural variables on the outcome of the unprotected left main coronary artery (uLMCA) itself after drug-eluting stent (DES) implantation.BackgroundThere is a controversial debate regarding when and how to perform percutaneous coronary intervention (PCI) for an uLMCA stenosis.MethodsThis analysis is based on a randomized study of 607 patients undergoing PCI for uLMCA, randomized 1:1 to receive paclitaxel- or sirolimus-eluting stents. We evaluated the impact of the SYNTAX score, uLMCA anatomy, and stenting technique on in-stent restenosis (ISR), target lesion revascularization (TLR), and the 3-year outcomes.ResultsThe 3-year cardiac mortality rate was 5.8%; 235 (39%) patients had a true bifurcation lesion (TBL), and the median SYNTAX score was 27. TBL was associated with a higher need for multiple stents (72% vs. 37%, p < 0.001). TBL was a significant predictor of ISR (23% vs. 14%, p = 0.008) and for TLR (18% vs. 9%, p < 0.001). The need for multiple stents was a predictor of ISR (22% vs. 13%, p = 0.005) and for TLR (16% vs. 9%, p = 0.005). Culotte stenting showed better results compared with T-stenting for ISR (21% vs. 56%, p = 0.02) and for TLR (15% vs. 56%, p < 0.001). We observed a significant association between uLMCA-TLR and SYNTAX scores (9.2% for scores â€22, 14.9% for scores 23 to 32, and 13.0% for scores â„33, p = 0.008).ConclusionsPCI of uLMCA lesions with DES is safe and effective out to 3 years. TBL and multiple stents were independent predictors for ISR. In the multivariate analysis, independent predictors for TLR were TBL, age, and EuroSCORE (European System for Cardiac Operative Risk Evaluation). (Drug-Eluting-Stents for Unprotected Left Main Stem Disease [ISAR-LEFT-MAIN]; NCT00133237
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