Characterization of Kemp's Ridley Sea Turtles in the Florida Big Bend Area: Final report

The Kemp's ridley (Lepidochelys kempo is considered the most endangered of the seven extant marine turtle species (Ross et al. 1989). The US Fish and Wildlife Service (USFWS) and the National Marine Fisheries Service (NMFS) estimate the breeding population at 1,500 to 3,000 individuals. The nesting population has been reduced from approximately 40,000 on one day to no more than 700 annually (Magnuson et al. 1990, USFWS & NMFS 1992). Conservation measures for the species have focused on the protection of the nesting beach, captive rearing (head starting), and the implementation of turtle excluder devices (TEDs) on shrimp nets. Five hundred to 5,000 ridleys are still taken incidentally yearly by shrimp trawls (Magnuson et al. 1990). Lack of knowledge about early life stages of the Kemp's ridley sea turtle currently hinders recovery efforts for this federally listed species. (Document has 18 pages.

SEX IN THE SUWANNEE THE SECRETIVE LOVE LIFE OF GULF STURGEONS

Mid-February in the Gulf of Mexico and a timeless ritual is about to repeat itself for perhaps the millionth time. Some mysterious signal, possibly increasing day length, flips an internal switch, feeding stops, and the homeward migration begins for the Gulf Sturgeon (Acipenser oxyrinchus desotoi). From far flung places along the Gulf Coast, Gulf Sturgeons start heading back to their natal rivers – they know the way instinctively. Maybe they seek out the special chemical taste of their home river, imprinted at hatching. Or perhaps the ultrasensitive electric organs decorating the underside of the snout can follow the map of the earth’s magnetic field. Either way, time to make a beeline for the welcoming waters of the Suwannee River, or maybe the Apalachicola, Choctawhatchee, or one of four other spawning rivers. Some of the adults are on a special mission – time to spawn, time to perpetuate the species. Mature males form the first wave in this homebound marathon, eager to get to the spawning grounds, eager to be the first to greet ready females with a series of sharp clicking sounds. Only spawning once each three years, females laden with large black eggs demure, taking their time, arriving in mid to late March, a month behind the early males. But most sturgeons, juveniles and immature adults not ready to spawn, are simply heading home. Not prompted by the spawning urge, they are just following the ancient annual cycle of intense winter feeding in the Gulf, followed by several months of fasting and R&R in the river

Catching Air - Those Magnificent Jumping Suwannee Sturgeons

It starts deep at the bottom of the dark silent river, three to four powerful tail beats and three sharp acoustic clicks. Then, a sudden upturn of the body and the fish explodes upward, 100 pounds going vertical, catching air, lots of air. A good jump can power a big fish, six to nine feet into the air. You have to be quick to get a photo, hang time is only about a second, but an accomplished jump by a big old Suwannee River Gulf Sturgeon is impressive; a magnificent display of power. The exit is almost vertical. The tail continues to beat back and forth as the fish rises. Then, comes a half-twist of the body, sometimes a full 180-degree twist, followed by that signature loud body smack on the surface; a sturgeon version of the belly-flop. Nothing else on the river sounds like it. If you happen to be close by, the report is really impressive, if not downright scary. In the calm of the night, when the air is still, and nary a boat is stirring, that startling report can be heard from a mile or more away, even further underwater by another sturgeon. A loud splash upon re-entry isn’t the end of the sequence. At the peak of its jump, the big fish gulps air, re-filling its long swim bladder. Hitting the water, it immediately powers down deep, emitting one more sharp snapping sound on the way down, disappearing into the deep for another day

Application of S-parameter techniques to amplifier design

1. Discussion of s parameters and their applicability to high frequency design. 2. Measurement of s parameters and evaluation of stable operating regions. 3. Synthesis of high frequency transistor circuitry with the aid of scattering parameter design equations. 4. Verification of design theory by evaluating the performance of bread-board models

What Makes a Font Persuasive?: An Eye-Tracking Study of Perception in American and Chinese Assessment of Fonts

Professional, technical, and visual communication practitioners and academics have historically overlooked visual rhetoric and how it is employed in business communications as well as how various cultures comprehend and respond to the design elements and visual composition of business documents. More specifically typography, the building blocks of a document, has been little explored in professional and technical communication research. As such, this study utilizes eye-tracking technology in conjunction with other data collection methods to understand if and how fonts contribute to the persuasiveness of business communications and if different cultures vary in typeface assessment and perception. Mackiewicz and Brumberger have both examined typeface anatomy and its effect on perception of font personality. Similar methods are implemented in this study to determine if the anatomical characteristics of fonts contribute to the perception of typeface persuasiveness in business documents. Furthermore, this study also seeks to establish if any correlations exist in typeface persuasiveness between American and Chinese cultures. Through this study, it was discovered that there are in fact anatomical characteristics of typefaces that lend themselves to a font being perceived as persuasive. It was also found that the perception of persuasiveness differs between the two cultures, and the methods by which the two groups assess the typefaces for persuasiveness are quite distinct

Mudfish on the Menu? Rise of the Much-Maligned Bowfin

Cajuns call it “choupique” (say “shoe-pick”), from its Choctaw name. Elsewhere, it’s the dogfish, blackfish, grindle, cottonfish, or cypress trout. Its official common name is “Bowfin” (Amia calva)1. But to most anglers, this is the “mudfish,” a strange, unusual, and much-maligned fish, most everywhere considered a useless trash fish. One look and the words relict, prehistoric, primitive, and living fossil come to mind. Indeed, the bowfin is the last of its line, the sole-surviving species of a very ancient group of fishes. Its predecessors flourished in the Jurassic and Cretaceous periods during the Mesozoic (= Middle-Animal) Era, a great expanse of geological time. Yes, as commonly noted, the mudfish is a holdover from the age of the dinosaurs, 60-150 mil­lion years ago. Other equally ancient holdovers among freshwater fishes are its very distant cousins, the gars, and the sturgeons and Paddlefish, all equally antique, all unique and unusual, all northern hemi­sphere fishes. All three watched Tyrannosaurus come and go. They withstood the tropical Mesozoic, then dramatic global cooling when the Atlantic Ocean began to open 80 million years ago, and again when ice held much of Europe, Asia and North America in the chilling grip of the Pleistocene Ice Age for 2.6 million years. All three antique fishes witnessed the evolution of grasses, flowering plants, and woody trees, as earlier forests of fern trees and giant horsetail rushes disappeared from northern continents. Bow­fins, gars, and sturgeons outlasted the sabretooth tiger, the wooly mammoth, Nethanderthal man, and will most likely outlast the human species – if we do not drive them to extinction first (we have already done in or pushed to the brink five of the world’s 26 sturgeon species, and one paddlefish2). But, back to the dinosaur comparison. In proportion to its size, the mudfish is armed with a wicked set of long, sharp, curved teeth on nearly every bone in its mouth. If scaled up to dino dimensions, its teeth would close­ly resemble, and rival the size of those of many meat-eaters dinosaurs. And – the mudfish also sports the thickest, densest skull bones of any fish – armored like a dinosaur as well. It is an elegantly designed predator and survivor indeed

The Inky Story of the Dinky Oak Gall

Maybe you have noticed these little spheres before – but did not give them much thought. Or maybe, you puzzled: What are these wooden pearls? How did they get there? Well, a tiny wasp, called the pea galler wasp or gallfly, Belonocnema treatae, is the culprit. The diminutive female gallfly (one of nearly a thousand species in the gall wasp family Cynipidae), about the size of a fire ant, lays eggs on a freshly budded live oak leaf in spring. When the larva hatches, it produces a chemical that induces the oak to enclose it in a protective and nurturing gall: nifty chemical subterfuge, producing a durable little house for the gall wasp larva – no house of bricks, but nearly as good – indeed maybe even better. It comes equipped with a food supply as well. At the chemical direction of the larva, the gall provides an inner layer of nitrogen-rich pulp, similar to seed tissue. A tough lignin-rich1 outer layer protects the larva from predators, and a chemical shield of anti-microbial tannic acid is concentrated within. Tannic (or gallotannic) acid concentrated in the gall is the tree’s way of isolating the parasitic larva. Ironically, however, the same phenol-rich barrier helps deter predators and disease. Perhaps the bitter taste of tannins and phenols may also discourage predation of gall larvae by birds

Catching Air - Those Magnificent Jumping Suwannee Sturgeons

It starts deep at the bottom of the dark silent river, three to four powerful tail beats and three sharp acoustic clicks. Then, a sudden upturn of the body and the fish explodes upward, 100 pounds going vertical, catching air, lots of air. A good jump can power a big fish, six to nine feet into the air. You have to be quick to get a photo, hang time is only about a second, but an accomplished jump by a big old Suwannee River Gulf Sturgeon is impressive; a magnificent display of power. The exit is almost vertical. The tail continues to beat back and forth as the fish rises. Then, comes a half-twist of the body, sometimes a full 180-degree twist, followed by that signature loud body smack on the surface; a sturgeon version of the belly-flop. Nothing else on the river sounds like it. If you happen to be close by, the report is really impressive, if not downright scary. In the calm of the night, when the air is still, and nary a boat is stirring, that startling report can be heard from a mile or more away, even further underwater by another sturgeon. A loud splash upon re-entry isn’t the end of the sequence. At the peak of its jump, the big fish gulps air, re-filling its long swim bladder. Hitting the water, it immediately powers down deep, emitting one more sharp snapping sound on the way down, disappearing into the deep for another day