Maturity and Fecundity of the White Perch, Morone americana, in Western Lake Erie

Author Institution: Sandusky Biological Station, Great Lakes Fishery Laboratory, U.S. Fish and Wildlife ServiceAmong white perch {Morone americana) collected from bottom trawl catches in 1984 and commercial trap net catches in 1985, all males were mature at age 2, and all females by age 3. Fecundity estimates for 50 females collected in May, 1985 ranged from 64,480 to 388,736 eggs (x ± SE=174,945±10,198)

Pulmonary epithelial cells as model to investigate in vivo drug absorption across the human air-blood barrier

The lung is more and more of interest for local as well as for systemic administration of drugs. Nevertheless, the development of modern inhalable medicines is moving forward only slowly. Especially the lack of safety and efficacy data combined with unsatisfactory in vitro models for the investigation of the complex processes on the air-blood barrier decelerates the development of new aerosol medicines. In the first part of this thesis the transport of peptides with different molecular weight across submersed human alveolar epithelial cells has been investigated. The measured absorption/ secretion rates allow quantifying of permeability and the identification of active or passive transports, but the influence of formulation parameters like size or charge disappears after preparing solutions and adding these in the fluid filled apical compartment of submersed cell culture. However, with the aid of a relatively simple insufflator syringe and air interface cultivated cells, a deposition more close to the in vivo situation was possible. It was found that air interface deposition yielded higher absorption rates and that differences in particle size significantly influenced the absorption rates only after air interface deposition but not after liquid interface deposition. Even if the application with the insufflator syringe offers the opportunity to deposit dry particles on the air interface of cell monolayers the method wasn\u27;t able to simulate in vivo relevant impaction processes. Especially in case of dry powder aerosols composed of large carrier lactose particles and adherent micronized drug crystals, impaction processes during aerosolisation normally accomplish separation of the drug from the carrier. Only the sufficiently small (< 5 µm) drug crystals are deposited in the deeper regions of the lung. As the insufflator fails to separate the drug crystals from the carrier lactose, and as the particle size of the carrier particles significantly influences the dissolution and absorption behaviour, a cell compatible aerosol impingement system was designed. A commercial available MSLI was modified to incorporate cell culture inserts in the relevant stages. Complex powder formulations could be size fractionated and the size fractions which are able to reach in vivo the deep lung were deposited on cell monolayers. Significantly changed absorption behaviour could be detected in dependency of cell culture fluid volume, particle size and deposition mode.Im ersten Teil der Dissertation wurde die Permeation von gelösten Peptiden mit verschiedenem Molekulargewicht durch Monolayer humaner alveolarer Epithelzellen untersucht. Auch wenn das Arbeiten mit Lösungen für die Untersuchung intestinaler Absorptionsvorgänge die in vivo Situation ausreichend genau wiedergibt, stellt diese Methode keine realistische Applikationsart für Aerosole dar, da die menschliche Luft-Blut-Schranke beim gesunden Patienten nur mit einem ausgesprochen dünnen Flüssigkeitsfilm bedeckt ist, der nur den hundertsten Teil der Dicke üblicher Flüssigkeitsschichten in submersen Zellkulturen ausmacht. Realitätsnah lassen sich jedoch Calu-3 Zellen als Modelle des Bronchialepithels, und primäre humane alveolare Epithelzellen als Modell der alveolaren Bereiche der Lunge, ohne flüssigkeitsgefülltes apikales Kompartiment kultivieren. Im zweiten Teil der Arbeit wurde mittels solcher an der Luft-Grenzschicht kultivierter zellulärer Modelle untersucht inwiefern die Applikation als Lösung oder in Form eines trockenen Pulveraerosols den Transport von Arzneistoffen beeinflusst. Nach Deposition trockener Aerosolformulierungen auf Luft-Grenzschicht kultivierte Zellen konnten signifikant schnellere Resorptionsvorgänge gemessen werden. Obwohl die angewandte Applikation mittels einer Insufflator Spritze an sich schon eine sinnvolle Verbesserung von Transportexperimenten an Modellen der Luft-Blutschranke darstellt, berücksichtigt die Insufflator Spritze nicht alle Aerosol Charakteristika. Vor allem im Falle von Aerosolen mit Laktose Partikeln als Wirkstoffträger war die Insufflator Spritze nicht in der Lage die Separation der mikronisierten Arzneistoffkristalle von den wesentlich größeren Laktose Trägern zu bewerkstelligen. Um auch diese Prozesse wirklichkeitsnah zu simulieren wurde im dritten Abschnitt der Arbeit ein zellkompatibler Kaskaden-Impaktor entwickelt. In diesem war es möglich sowohl eine realistische Auftrennung der Aerosole nach der Partikelgröße als auch die Deposition der einzelnen Partikelfraktionen auf Luft-Grenzschicht kultivierte Zellmonolayer nachzuahmen

NASA Innovative Advanced Concepts (NIAC) Phase 1 Final Report: Venus Landsailer Zephyr

Imagine sailing across the hot plains of Venus! A design for a craft to do just this was completed by the COncurrent Multidisciplinary Preliminary Assessment of Space Systems (COMPASS) Team for the NASA Innovative Advanced Concepts (NIAC) project. The robotic craft could explore over 30 km of surface of Venus, driven by the power of the wind

Evaluation of harassment of migrating double-crested cormorants to limit depredation on selected sport fisheries in Michigan

Diverse management techniques have been used to mitigate conflicts between humans and double-crested cormorants (Phalacrocorax auritus) including harassment methods supplemented by lethal take. In this study we evaluated impacts or programs to harass spring migrating cormorants on the walleye (Sander vitreus) fishery in Brevoort Lake and the yellow perch (Perca flavescens ) and walleye fisheries at Drummond Island. Cormorant foraging declined significantly (p \u3c 0.05) at both locations subsequent to initiation of harassment programs. Overall harassment deteired 90% of cormorant foraging attempts while taking less than 6% lethally on average at each site. Yellow perch were a predominate prey item in number and biomass at both locations. Walleye made up a small proportion of the diet at both locations. However, both walleye and yellow perch abundance increased significantly (p\u3c0.05) at Drummond Island. Walleye abundance at age 3 increased to record levels in 2008 following 3 years of cormorant management at Brevoort Lake. The estimated cormorant consumption of age 1 walleye in the absence of management at Brevoort Lake during 2005 would account for 55% of the record 2006 age 1 walleye population. These results support the hypothesis, that cormorant predation on spawning aggregations of sportfish was a significant mortality factor and cormorant management reduced sportfish mortality and increased abundance at both locations. Continuation of harassment programs and .fishery assessments will determine whether improvement of targeted sport fisheries through control of spring migrating cormorants is sustainable

A CubeSat Asteroid Mission: Design Study and Trade-Offs

There is considerable interest in expanding the applicability of cubesat spacecraft into lightweight, low cost missions beyond Low Earth Orbit. A conceptual design was done for a 6-U cubesat for a technology demonstration to demonstrate use of electric propulsion systems on a small satellite platform. The candidate objective was a mission to be launched on the SLS test launch EM-1 to visit a Near-Earth asteroid. Both asteroid fly-by and asteroid rendezvous missions were analyzed. Propulsion systems analyzed included cold-gas thruster systems, Hall and ion thrusters, incorporating either Xenon or Iodine propellant, and an electrospray thruster. The mission takes advantage of the ability of the SLS launch to place it into an initial trajectory of C3=0. Targeting asteroids that fly close to earth minimizes the propulsion required for fly-by/rendezvous. Due to mass constraints, high specific impulse is required, and volume constraints mean the propellant density was also of great importance to the ability to achieve the required deltaV. This improves the relative usefulness of the electrospray salt, with higher propellant density. In order to minimize high pressure tanks and volatiles, the salt electrospray and iodine ion propulsion systems were the optimum designs for the fly-by and rendezvous missions respectively combined with a thruster gimbal and wheel system For the candidate fly-by mission, with a mission deltaV of about 400 m/s, the mission objectives could be accomplished with a 800s electrospray propulsion system, incorporating a propellant-less cathode and a bellows salt tank. This propulsion system is planned for demonstration on 2015 LEO and 2016 GEO DARPA flights. For the rendezvous mission, at a V of 2000 m/s, the mission could be accomplished with a 50W miniature ion propulsion system running iodine propellant. This propulsion system is not yet demonstrated in space. The conceptual design shows that an asteroid mission is possible using a cubesat platform with high-efficiency electric propulsion

Advanced Lithium Ion Venus Explorer (ALIVE)

The COncurrent Multidisciplinary Preliminary Assessment of Space Systems (COMPASS) Team partnered with the Applied Research Laboratory to perform a NASA Innovative Advanced Concepts (NIAC) Program study to evaluate chemical based power systems for keeping a Venus lander alive (power and cooling) and functional for a period of days. The mission class targeted was either a Discovery ($500M) or New Frontiers ($750M to $780M) class mission. Historic Soviet Venus landers have only lasted on the order of 2 hours in the extreme Venus environment:temperatures of 460 degrees Centigrade and pressures of 93 bar. Longer duration missions have been studied using plutonium powered systems to operate and cool landers for up to a year. However, the plutonium load is very large. This NIAC study sought to still provide power and cooling but without the plutonium. Batteries are far too heavy but a system which uses the atmosphere (primarily carbon dioxide) and on on-board fuel to power a power generation and cooling system was sought. The resuling design was the Advanced Long-Life Lander Investigating the Venus Environment (ALIVE) Spacecraft (S/C) which burns lithium (Li) with the CO2 atmosphere to heat a Duplex Stirling to power and cool the lander for a 5-day duration (until the Li is exhausted). While it does not last years a chemical powered system surviving days eliminates the cost associated with utilizing a flyby relay S/C and allows a continuous low data rate direct to earth (DTE) link in this instance from the Ovda Regio of Venus. The five-day collection time provided by the chemical power systems also enables science personnel on earth to interact and retarget science - something not possible with an approximately 2-hour spacecraft lifetime. It also allows for contingency operations directed by the ground (reduced risk). The science package was based on that envisioned by the Venus Intrepid Tessera Lander (VITaL) Decadal Survey Study. The Li Burner within the long duration power system creates approximately 14000 W of heat. This 1300 degree Centigrade heat using Li in the bottom "ballast" tank is melted to liquid by the Venus temperature, drawn into a furnace by a wick and burned with atmospheric CO2. The Li carbonate exhaust is liquid at 1300 degrees Centigrade and being denser than Li drains into the the Li tank and solidifies. Since the exhaust product is a dense liquid no "chimney" is required which conserves the heat for the stirling power convertor. The Duplex Stirling provides about 300 W of power and removes about 300 W of heat from the avionics and heat that leaks into the 1-bar-insulated payload pressure vessel kept at 25 degrees Centigrade. The Na K radiator is run to the top of the drag flap.The ALIVE vehicle is carried to Venus via an Atlas 411 launch vehicle (LV) with a C3 of 7 km2/s2. An Aeroshell, derived from the Genesis mission, enables a direct entry into the atmosphere of Venus (-10 degrees Centigrade, 40 g max) and 6 m/s for landing (44 g) using a drag ring. For surface science and communication, a 100 WRF (WebEx Recording Format), X-Band 0.6-meter pointable DTE (Direct-to-Earth) antenna provides 2 kbps (kilobits per second) to DSN (Deep-Space Network) 34-meter antenna clusters.Table 1.1 summarizes the top-level details of each subsystem that was incorporated into the design. Cost estimates of the ALIVE mission show it at approximately$760M which puts it into the New Frontiers class.The ALIVE landed duration is only limited by the amount of Li which can be carried by the lander. Further studies are needed to investigate how additional mass can be carried, perhaps by a larger launcher and larger aeroshell