Comparison of Two Year Classes of Hybrid Grass Carp and Grass Carp for Aquatic Plant Control

Two year classes of grass carp and F, hybrids resulting from bighead carp male x grass carp female were compared at various stocking densities for aquatic plant control. One and two year old grass carp exhibited higher survival rates and better growth rates than the same age hybrid grass carp. The presence of grass carp or hybrid grass carp decreased both Secchi disc transparencies and dissolved oxygen values. Grass carp had a greater negative effect upon these measurements because they removed the vegetation quicker than the hybrid grass carp. These apparent detrimental effects on water quality are necessary trade-offs for vegetation removal by any method. Grass carp and hybrid grass carp utilized Chara sp., Potamogeton pectinatus, Hydrodicton sp., Rhizoclonia sp., and Pithophora sp. Two year old hybrid grass carp required approximately twice as much time as the same age grass carp to eliminate dense growths of the vegetation listed above. One year old hybrid grass carp were slightly less effective than one year old grass carp at controlling these same plant species. However, it was extremely difficult for one or two year old hybrid grass carp to totally eliminate dense growths of these plant species except at high stocking densities. The use of mean vegetation heights to indirectly measure total plant biomass was unacceptable whenever unpreferred floating plant species were present. The hybrid grass carp appeared to be a poor alternative biological control for nuisance aquatic vegetation when compared directly to the grass carp

Spawning the Grass Carp Female X Bighead Carp Male

Methods and procedures for artificially spawning the female grass carp (Ctenopharyngodon idella) X male bighead carp (Aristichthys nobilis) are presented. Broodstock selection and treatment, hormone injections, ovulation, fertilization, hatching techniques and stocking rates are discussed. This paper outlines the procedures necessary to successfully produce hybrid grass car

Cover Crop Options to Consider for Damaged Crops this Fall

Many fields have been ravaged by adverse weather this year in Iowa. On top of drought and hail we had a devastating derecho steam-roll a wide swath of Iowa starting in Sac County and progressing eastward along Highway 30. Along with the decision of how to handle this year’s crop, consideration for protecting the soil and preparing for next year’s crop should include cover crops

Advanced Jet Noise Exhaust Concepts in NASA's N+2 Supersonics Validation Study and the Environmentally Responsible Aviation Project's Upcoming Hybrid Wing Body Acoustics Test

Acoustic and flow-field experiments were conducted on exhaust concepts for the next generation supersonic, commercial aircraft. The concepts were developed by Lockheed Martin (LM), Rolls-Royce Liberty Works (RRLW), and General Electric Global Research (GEGR) as part of an N+2 (next generation forward) aircraft system study initiated by the Supersonics Project in NASA s Fundamental Aeronautics Program. The experiments were conducted in the Aero-Acoustic Propulsion Laboratory at the NASA Glenn Research Center. The exhaust concepts presented here utilized lobed-mixers and ejectors. A powered third-stream was implemented to improve ejector acoustic performance. One concept was found to produce stagnant flow within the ejector and the other produced discrete-frequency tones (due to flow separations within the model) that degraded the acoustic performance of the exhaust concept. NASA's Environmentally Responsible Aviation (ERA) Project has been investigating a Hybrid Wing Body (HWB) aircraft as a possible configuration for meeting N+2 system level goals for noise, emissions, and fuel burn. A recently completed NRA led by Boeing Research and Technology resulted in a full-scale aircraft design and wind tunnel model. This model will be tested acoustically in NASA Langley's 14-by 22-Foot Subsonic Tunnel and will include dual jet engine simulators and broadband engine noise simulators as part of the test campaign. The objectives of the test are to characterize the system level noise, quantify the effects of shielding, and generate a valuable database for prediction method development. Further details of the test and various component preparations are described

Decisional support for young people who self-harm: protocol for a feasibility trial

Introduction: Self-harm is common in adolescents and it is the strongest predictor of suicide. Young people who self-harm are often unsure of how and where to get help. Decision aids (DA) have been shown to help with decisional conflict where there is uncertainty around different options. We have developed an online DA to support young people in help-seeking for self-harm. A feasibility trial will examine the acceptability of the online intervention, and the ability to recruit and follow-up participants within a school setting. Methods and Analysis: In this parallel arm, single blind feasibility trial, 60 participants aged 12-18 years who have self-harmed in the past 12 months, will be randomised to either: 1) a group receiving the online DA or 2) a control group receiving general information about feelings and emotions. Both groups will complete measures assessing decision-making and help-seeking behaviour. The school counsellor will be notified of any participants who have been randomised to ensure safeguarding for the young person. Participants in both groups will be followed up at 4-weeks and the measures will be repeated. Qualitative interviews will be conducted with a subset of participants to explore their views and experiences of the DA and of participation in the study. Ethics and Dissemination: Ethical approval was granted by King’s College London (KCL) College Research Ethics Committee. Results of this study will help to clarify if we can recruit and administer an online decisional support intervention within a school setting for young people who self-harm. The study will inform the design and implementation of a larger randomised controlled trial to test the effectiveness of the DA. Dissemination of the study findings will target publication in peer-reviewed journals of general and special interest. The funder will be sent a report outlining the major findings of the study

The Heritage of the Deep: Finding s/s Stefano

It has been long since been considered that the Black Rock, a dangerous, isolated reef near Point Cloates, Western Australia (WA) was the place where the barque Stefano (owned by the Baccic family from Dubrovnik, during the Austro-Hungarian Monarchy) was wrecked in 1875. There were only two survivors of 17 crew members (all Croatians from Dalmatia, majority from the region of Dubrovnik and bar one English boy). The modern underwater scientific search for Stefano started at the beginning of the 1980s’ under the leadership of Graeme Henderson then Curator of Maritime Archaeology at the WA Maritime Museum at Fremantle. He developed the Museum’s colonial shipwrecks management programme and, together with his wife Kandy-Jane Henderson, who was an archivist in the State Archives of WA, published the book on shipwrecks in which the Stefano featured entitled Unfinished voyages 1851-1880. In 1988 Graeme Henderson won the Australian Heritage Award for an outstanding contribution to the preservation and promotion of Australian heritage and environment. While searching for the wreck of the Portuguese despatch vessel Correio d’ Azia lost near Point Cloates in 1816, Henderson was also searching for evidence of the Stefano tragedy of October 27th 1875. His search of nearby Ningaloo Reef was without the expected result, however. Success was had almost at the end of the 1990s’ by a four-member team led by Jeremy Green, a remote-sensing specialist and Head of the Department of Maritime Archaeology. With him on that occasion was Mike McCarthy, Bob Richards and senior technical officer Geoff Kimpton. It was he who, while being towed underwater, all of a sudden, spotted a davit, and later what appeared to be an anchor from Stefano. The discovery of the Stefano wreck extended the number of scientists and experts from different fields interested in the case