Tank Systems on Shrimp Farms Are Effective for Extension Demonstrations in Aquaculture

Numerous approaches can be implemented to carry out on-farm Extension demonstrations in aquaculture. The design and approach used are often governed by the problem or question that needs to be addressed as well as budgetary constraints within Extension programs. West Alabama is home to a unique inland marine shrimp industry that uses a low-salinity artesian groundwater source to raise shrimp. Demonstration and technology transfer have been carried out on commercial shrimp farms for nearly 20 years using low-budget on-levee tank systems operated by Extension personnel using this unique water source. On-farm tank demonstrations can be an effective tool for Extension professionals working in aquaculture, especially where unique circumstances exist

Anomalous Seismic Amplitudes Measured in the Los Angeles Basin Interpreted as a Basin-Edge Diffraction Catastrophe

The Los Angeles Basin Passive Seismic Experiment (labpse) involved the installation of an array of 18 seismic stations along a line crossing the Los Angeles basin from the foothills of the San Gabriel Mountains through the Puente Hills to the coast. At 3–5 km spacing between stations the array has much higher resolution than the permanent network of stations in southern California. This resolution was found to be important for analyzing the factors that govern the amplitude variation across the basin. We inverted spectra of P- and S-body-wave seismograms from local earthquakes (M_L 2.1–4.8) for site effects, attenuation, and corner frequency factor using a standard model that assumes geometric spreading varying as inverse distance, exponential attenuation, and an ω^2 source model. The S-wave attenuation was separable into basin and bedrock contributions. In addition to the body-wave analysis, S-wave coda were analyzed for coda Q and coda-determined site effects. We find S- wave Q (Q_S) in bedrock is higher than in the basin. High-frequency Q_S is higher than low-frequency Q_S. Coda Q (Q_c) is higher than Q_S. P-wave Q (Q_P) was not separable into basement and bedrock values, so we determined an average value only. The corner frequencies for P and S waves were found to be nearly the same. The standard model fit over 97% of the S-wave data, but data from six clustered events incident along the basin edge within a restricted range of incidence and azimuth angles generated anomalous amplitudes of up to a factor of 5 higher than predicted. We test whether such basin-edge focusing might be modeled by catastrophe theory. After ruling out site, attenuation, and radiation effects, we conclude a caustic modeled as a diffraction catastrophe could explain both the frequency and spatial dependence of the anomalous variation

Spectral Line Imaging Observations of 1E0102.2-7219

E0102-72 is the second brightest X-ray source in the Small Magellanic Cloud and the brightest supernova remnant in the SMC. We observed this SNR for ~140 ksec with the High Energy Transmission Gratings (HETG) aboard the Chandra X-ray Observatory. The small angular size and high surface brightness make this an excellent target for HETG and we resolve the remnant into individual lines. We observe fluxes from several lines which include O VIII Ly$\alpha$, Ly$\beta$, and O VII along with several lines from Ne X, Ne IX and Mg XII. These line ratios provide powerful constraints on the electron temperature and the ionization age of the remnant.Comment: To appear in "Young Supernova Remnants" (11th Annual Astrophysics Conference in Maryland), S. S. Holt & U. Hwang (eds), AIP, New York (2001

Scanning and Transmission Electron Microscopic Study of Recovered Porcine Aortic Valved Conduits

Four explanted porcine aortic valved conduits were examined using scanning and transmission electron microscopy. Sources of obstruction such as neointima or peel and calcification were observed. In one sample the neointima was found to possess an unusually large expanse of squamous cells partially lining the luminal surface. This lining much resembled a normal endothelium, which is not an expected feature of neointima. Cells, presumably of host origin, were noted upon the leaflet surfaces. They did not seem as well organized as those found on the neointima. Calcification did not seem greatly advanced but was clearly apparent. Certain treatments proposed by others to curtail calcification are discussed and amended herein. SEM examination of three of these conduits provided good evidence of lining cells on only the inflow surface of the leaflet. The fourth conduit, however, showed cells on both inflow and outflow surfaces. These cells possessed certain characteristics of cells from leaflets of the other three conduits, but questions remain as to the precise identification of all of these lining cells. TEM examination provided cytological evidence of macrophage-like cells lining the inflow surface of a leaflet

The Ursinus Weekly, April 25, 1938

Coeds choose Lees, Poling, Claflin leaders • Harrisburg group hears Ade, Toll at conclave • Dictators main peace threat say conference leaders • Plays Saturday night week-end feature • May sports hop makes lucky Friday 13 • Wimer new YM head; appoints cabinet • Alumnus develops Sweden in Forefathers address • Stoudt, Craigie to play leads in First lady • Girls hear vocation charts by career women • Embryo lawyers discuss organization of club • Mikado again in rehearsal • Temple leads • Charm, attractiveness, especially a mysterious allurement • Musical variety features club\u27s Easter program • Pre-meds to hear Dr. Eger at next week\u27s meeting • Clawson addresses Berks County math club • Sheeder, Old, Ursinus visit Lansdale, Camden schools • Batsmen beat Lehigh, but lose to Lafayette • Stine close victory in intramural tourney • Cindermen place third in meet at Drexel • Ware\u27s racketeers down Bryn Mawr Sat. 3-2 • \u27Sinus second college in U.S. with cricket team • Hill defeats bear J.V.s 9-5; meet Villanova today • Musical organizations hold concert in Bomberger • Witmer addresses faculty club at April meeting • Frosh parade makes College Humor • Women end forensic season • Baird, Martin, DeWire to enter graduate schools • Biology students spend week-end in New York • Ursinus line coach to wed during football seasonhttps://digitalcommons.ursinus.edu/weekly/1897/thumbnail.jp

The Three-Dimensional Structure of Cassiopeia A

We used the Spitzer Space Telescope's Infrared Spectrograph to map nearly the entire extent of Cassiopeia A between 5-40 micron. Using infrared and Chandra X-ray Doppler velocity measurements, along with the locations of optical ejecta beyond the forward shock, we constructed a 3-D model of the remnant. The structure of Cas A can be characterized into a spherical component, a tilted thick disk, and multiple ejecta jets/pistons and optical fast-moving knots all populating the thick disk plane. The Bright Ring in Cas A identifies the intersection between the thick plane/pistons and a roughly spherical reverse shock. The ejecta pistons indicate a radial velocity gradient in the explosion. Some ejecta pistons are bipolar with oppositely-directed flows about the expansion center while some ejecta pistons show no such symmetry. Some ejecta pistons appear to maintain the integrity of the nuclear burning layers while others appear to have punched through the outer layers. The ejecta pistons indicate a radial velocity gradient in the explosion. In 3-D, the Fe jet in the southeast occupies a "hole" in the Si-group emission and does not represent "overturning", as previously thought. Although interaction with the circumstellar medium affects the detailed appearance of the remnant and may affect the visibility of the southeast Fe jet, the bulk of the symmetries and asymmetries in Cas A are intrinsic to the explosion.Comment: Accepted to ApJ. 54 pages, 21 figures. For high resolution figures and associated mpeg movie and 3D PDF files, see http://homepages.spa.umn.edu/~tdelaney/pape

Evolution of a global string network in a matter dominated universe

We evolve the network of global strings in the matter-dominated universe by means of numerical simulations. The existence of the scaling solution is confirmed as in the radiation-dominated universe but the scaling parameter $\xi$ takes a slightly smaller value, $\xi \simeq 0.6 \pm 0.1$, which is defined as $\xi = \rho_{s} t^{2} / \mu$ with $\rho_{s}$ the energy density of global strings and $\mu$ the string tension per unit length. The change of $\xi$ from the radiation to the matter-dominated universe is consistent with that obtained by Albrecht and Turok by use of the one-scale model. We also study the loop distribution function and find that it can be well fitted with that predicted by the one-scale model, where the number density $n_{l}(t)$ of the loop with the length $l$ is given by $n_{l}(t) = \nu/[t^2 (l + \kappa t)^2]$ with $\nu \sim 0.040$ and $\kappa \sim 0.48$. Thus, the evolution of the global string network in the matter-dominated universe can be well described by the one-scale model as in the radiation-dominated universe.Comment: 10 pages, 5 figure

Scaling Property of the global string in the radiation dominated universe

We investigate the evolution of the global string network in the radiation dominated universe by use of numerical simulations in 3+1 dimensions. We find that the global string network settles down to the scaling regime where the energy density of global strings, $\rho_{s}$, is given by $\rho_{s} = \xi \mu / t^2$ with $\mu$ the string tension per unit length and the scaling parameter, $\xi \sim (0.9-1.3)$, irrespective of the cosmic time. We also find that the loop distribution function can be fitted with that predicted by the so-called one scale model. Concretely, the number density, $n_{l}(t)$, of the loop with the length, $l$, is given by $n_{l}(t) = \nu/[t^{3/2} (l + \kappa t)^{5/2}]$ where $\nu \sim 0.0865$ and $\kappa$ is related with the Nambu-Goldstone(NG) boson radiation power from global strings, $P$, as $P = \kappa \mu$ with $\kappa \sim 0.535$. Therefore, the loop production function also scales and the typical scale of produced loops is nearly the horizon distance. Thus, the evolution of the global string network in the radiation dominated universe can be well described by the one scale model in contrast with that of the local string network.Comment: 18 pages, 9 figures, to appear in Phys. Rev.