49 research outputs found
A numerical study of the nonlinear interaction of Hurricane Camille with the Gulf of Mexico Loop Current
A three-dimensional, primitive equation, ocean general circulation model is used
to study the response of the Gulf of Mexico to Hurricane Camille (1969). The
free-surface dynamics and the mixed-layer features are included in the model.
The numerical model incorporates the realistic coastline and bottom topography.
The sigma coordinate model bas eighteen levels in the vertical and 0.2° x 0.2°
horizontal resolution for the entire gulf. The study focuses on nonlinear interaction
between hurricane induced currents and the Loop Current.
The numerical simulations show that there is a strong nonlinear interaction between
the hurricane and the Loop Current in the southern and central parts of the
eastern gulf. The surface currents due to nonlinear interaction obtain a maximum
of over 1 m s·1 in the southern gulf. The numerical results also show that the hurricane
interaction with the Loop Current strongly affects current, mixed-layer
depth, and elevation fields. There is a strong current response to Hurricane
Camille in the surface layer on the shelf with a peak velocity approximately 2.2 m
s-1âą There is a definite right band bias in the mixed-layer depth field with a maximum
of about 90 m.Navy Ocean Modeling and Prediction Program (NOMP) of the Office of Naval Research (ONR)Department of Oceanography, Naval Postgraduate SchoolNOAA Great Lakes Environmental Research LabsOceanweather, IncResearch Triangle InstituteNavy Ocean Modeling and Prediction Program (NOMP) of the Office of Naval Research (ONR)Department of Oceanography, Naval Postgraduate SchoolNOAA Great Lakes Environmental Research LabsOceanweather, IncResearch Triangle Institut
Evaluation of expression of P63 and amelogenin in human tooth germ and ameloblastoma
BACKGROUND:
The study was undertaken to evaluate the expression of p63 and amelogenin in human tooth germs and ameloblastomas by immunohistochemistry to find out whether the pattern of expression was related to differentiation of ameloblasts.
MATERIALS AND METHODS:
In this study fifteen human tooth germs of late bell stage, six human tooth germs of early bell stage and fifteen ameloblastoma samples were included and expression pattern of p63 and amelogenin were evaluated individually in all the samples.
RESULTS:
During the early bell stage, p63 expression was intense throughout the enamel organ. But, during the late bell stage, the number and intensity of p63 expression decreases in the cells of enamel organ. The peripheral cells in the ameloblastoma shows variable pattern of p63 expression. Expression of amelogenin was first evident in the presecretory ameloblasts at the cusp tip, followed by secretory ameloblasts and progresses cervically. But in ten late bell stage tooth germs, amelogenin expression was negative in the secretory ameloblasts and positive only at the secreting end i.e. tomes process. Intense staining was evident at the enamel matrix and in some dentinal tubules nearer to enamel matrix secretion. No amelogenin expression was evident in the dental papilla cells or odontoblasts throughout odontogenesis with the exception of dental follicle. Amelogenin expression was absent in eleven cases of ameloblastoma, but in four cases positive expression was evident at the peripheral cells.
CONCLUSION:
In the present study, the expression pattern of p63 and amelogenin in human tooth germ and ameloblastoma correlates with cytodifferentiation of ameloblasts
High origin of left testicular artery associated with accessory renal artery and renal cyst; a cadaveric observation
The variation in origin of the testicular artery is not uncommon, few reports about a high origin from the abdominal aorta exist in the literature. The renal artery is known to exhibit variations in its number and position. The knowledge of this variation will help the radiologists and surgeons in avoiding clinical complication during interventions. During routine dissection teaching to first year MBBS students at Sapthagiri Medical College, Bangalore we found variation in vascular pattern of testicular and renal artery associated with renal cyst. Photographs of the variations were taken. There was high origin of left testicular artery and accessory left renal artery associated with bilateral simple renal cyst in adult Male cadaver aged around 60years.There was also prehilar division of right renal artery associated with renal cyst. Anomalies in the origin, course and number of testicular artery were observed in 4.7 percent of cases. Additional renal vessels are known as the accessory renal artery and their incidence varies between 9-76%. In the present case there was high origin of left testicular artery associated with accessory renal artery and renal cyst. This anatomical knowledge of the presence of accessory renal artery and high origin of testicular artery in this case is important for radiologists, surgeons and urologist in their clinical practice
Atmospheric Kelvin-Helmholtz b illows captured by the MU radar, lidars and a fish-eye camera
On June 11, 2015, a train of large-amplitude KelvinâHelmholtz (KH) billows was monitored by the Middle and Upper Atmosphere (MU) radar (Shigaraki MU Observatory, Japan) at the altitude ofâ~â6.5 km. Four to five KH billows in formation and decay stages were observed for about 20 min at the height of a strong speed shear (>â~â30 m sâ»Âčkmâ»Âč), just a few hundred meters above a mid-level cloud base. The turbulent billows had a spacing of about 3.5â4.0 km (3.71 km in average) and an aspect ratio (depth/spacing) ofâ~â0.3. The turbulence kinetic energy dissipation rate estimated was of the order of 10â50 mWkgâ»Âč, corresponding to moderate turbulence according to ICAO (2010) classification. By chance, an upward-looking fish-eye camera producing pictures once every minute detected smooth protuberances at the cloud base caused by the KH billows so that comparisons of their characteristics could be made for the first time between the radar observations and the pictures. The main characteristics of the KH wave (horizontal wavelength, phase front direction and phase speed) obtained from the analysis of the pictures were fully consistent with those found from radar data. The pictures indicated that the billows were advected by the wind observed at the height of the critical level. They also revealed a very small transverse extent (about twice the horizontal spacing) suggesting that the large-amplitude KH billows were generated by a very localized source. Micro-pulse lidar and RamanâRayleighâMie lidar data also collected during the event permitted us to confirm some of the characteristics of the billows
Demonstration of a Real Time Capability to Produce Tidal Heights and Currents for Naval Operational Use: A Cast Study for the West Coast of Africa (Liberia)
This report documents an existing capability to produce operationally relevant products on sea level and currents from a tides/storm surge model for any coastal region around the world within 48 hours from the time of the request. The model is ready for transition to the Naval Oceanographic Office (NAVOCEANO) for potential contingency use anywhere around the world. A recent application to naval operations offshore Liberia illustrates this. Mississippi State University, in collaboration with the University of Colorado and NAVOCEANO, successfully deployed the Colorado University Rapidly Relocatable Nestable Tides and Storm Surge (CURReNTSS) model that predicts sea surface height, tidal currents and storm surge, and provided operational products on tidal sea level and currents in the littoral region off south-western coast of Africa. This report summarizes the results of this collaborative effort in an actual contingency use of the relocatable model, summarizes the lessons learned, and provides recommendations for further evaluation and transition of this modeling capability to operational use
Turbulence Kinetic Energy Dissipation Rates Estimated from Concurrent UAV and MU Radar Measurement s
We tested models commonly used for estimating turbulence kinetic energy dissipation rates Δ from very high frequency stratosphereâtroposphere radar data. These models relate the root-mean-square value Ï of radial velocity fluctuations assessed from radar Doppler spectra to Δ. For this purpose, we used data collected from the middle and upper atmosphere (MU) radar during the Shigaraki unmanned aerial vehicle (UAV)âradar experiment campaigns carried out at the Shigaraki MU Observatory, Japan, in June 2016 and 2017. On these occasions, UAVs equipped with fast-response and low-noise Pitot tube sensors for turbulence measurements were operated in the immediate vicinity of the MU radar. Radar-derived dissipation rates Δ estimated from the various models at a range resolution of 150 m from the altitude of 1.345 km up to the altitude ofâ~â4.0 km, a (half width half power) beam aperture of 1.32° and a time resolution of 24.6 s, were compared to dissipation rates (ΔU) directly obtained from relative wind speed spectra inferred from UAV measurements. Firstly, statistical analysis results revealed a very close relationship between enhancements of Ï and ΔU for ΔUâł10â»â”mÂČsâ»Âł, , indicating that both instruments detected the same turbulent events with ΔU above this threshold. Secondly, ΔU was found to be statistically proportional to ÏÂł, whereas a ÏÂČ than the longitudinal and transverse dimensions of the radar sampling volume. The ÏÂł dependence was found even after excluding convectively generated turbulence in the planetary boundary layer and below clouds. The best agreement between ΔU and radar-derived Δ was obtained with the simple formulation based on dimensional analysis Δ=ÏÂł /Lc where LC â 50â70 m. This empirical expression constitutes a simple way to estimate dissipation rates in the lower troposphere from MU radar data whatever the sources of turbulence be, in clear air or cloudy conditions, consistent with UAV estimates
Barotropic Tidal Predictions and Validation in a Relocatable Modeling Environment
Under funding from the Office of Naval Research (ONR), and the Naval Oceanographic Office (NAVOCEANO), the Mississippi State University Center for Air Sea Technology (CAST) has been working on developing a Relocatable Modeling Environment(RME) to provide a uniform and unbiased infrastructure for efficiently configuring numerical models in any geographic/oceanic region. Under Naval Oceanographic Office (NAVO-CEANO) funding, the model was implemented and tested for NAVOCEANO use. With our current emphasis on ocean tidal modeling, CAST has adopted the Colorado University's numerical ocean model, known as CURReNTSS (Colorado University Rapidly Relocatable Nestable Storm Surge) Model, as the model of choice. During the RME development process, CURReNTSS has been relocated to several coastal oceanic regions, providing excellent results that demonstrate its veracity. This report documents the model validation results and provides a brief description of the Graphic user Interface (GUI)
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Estimation of Turbulence Parameters in the Lower Troposphere from ShUREX (2016-2017) UAV Data
Turbulence parameters in the lower troposphere (up to ~4.5 km) are estimated from measurements of high-resolution and fast-response cold-wire temperature and Pitot tube velocity from sensors onboard DataHawk Unmanned Aerial Vehicles (UAVs) operated at the Shigaraki Middle and Upper atmosphere (MU) Observatory during two ShUREX (Shigaraki UAV Radar Experiment) campaigns in 2016 and 2017. The practical processing methods used for estimating turbulence kinetic energy dissipation rate ε and temperature structure function parameter C T 2 from one-dimensional wind and temperature frequency spectra are first described in detail. Both are based on the identification of inertial (−5/3) subranges in respective spectra. Using a formulation relating ε and C T 2 valid for Kolmogorov turbulence in steady state, the flux Richardson number R f and the mixing efficiency χ m are then estimated. The statistical analysis confirms the variability of R f and χ m around ~ 0.13 − 0.14 and ~ 0.16 − 0.17 , respectively, values close to the canonical values found from some earlier experimental and theoretical studies of both the atmosphere and the oceans. The relevance of the interpretation of the inertial subranges in terms of Kolmogorov turbulence is confirmed by assessing the consistency of additional parameters, the Ozmidov length scale L O , the buoyancy Reynolds number R e b , and the gradient Richardson number Ri. Finally, a case study is presented showing altitude differences between the peaks of N 2 , C T 2 and ε , suggesting turbulent stirring at the margin of a stable temperature gradient sheet. The possible contribution of this sheet and layer structure on clear air radar backscattering mechanisms is examined.</p
Analysis of Fabrics Structure on the Character of Wicking
ABSTRACT In this article, the effect of weave pattern on fabric wicking was analyzed. Weaves are distributed into two groups, i.e. weaves, the floats of which are distributed in even intervals throughout the entire surface of fabric, and horizontally striped weaves. The wickability properties of all tested fabrics are determined using a newly developed electronic vertical wicking tester. It was determined that the results of wicking horizontally striped fabrics were higher than those of weaves with evenly distributed floats. Washburn's equation obeyed quite well when the time constant is near 0.5. In fact, the time constant for plain and fancy twill weave were exponentially lower than those of other fabrics. This can be considered a measure of fabric rigidity