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Open Journal of Animal Sciences 2023年第1期13卷 126-136页

作者： Jaid Freestone Jill M. Voorhees Nathan Huysman eric krebs Michael e. Barnes South Dakota game Fish and Parks McNenny State Fish Hatchery Spearfish USA

Juvenile rainbow trout Oncorhynchus mykiss were subjected to one of four treatments in a two-by-two experimental design: 1) fed at a density of 1.8 g/m3, 2) Fasted at 1.8 g/m3, 3) fed at 30.1 g/m3, and 4) fasted at 30.1 g/m3. Blood glucose and hematocrit were measured at 4, 6, 48, 168, and 336 hours after placement in one of the two rearing densities, with relative fin lengths and organosomatic indices recorded at 336 hours. glucose levels over time were not significantly different among the density and feeding treatments. Hematocrit levels over time were also not significantly different. Total lengths, weight, hepatosomatic index, viscerosomatic index, and any of the relative fin lengths were not significantly different between the high and low densities. However, the hepatosomatic index was significantly g.eater in the fed fish compared to those fasted. The splenosomatic index was significantly g.eater in the hig.er density treatment. These results likely indicate no short-term stress response to the hig.er rearing density used in this short-term experiment and no interaction between starvation and density-related stressors.

关键词： Rainbow Trout Density Feeding glucose Hematocrit

exploring new avenues in high repetition rate table-top coherent extreme ultraviolet sources

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Light(Science & Applications) 2015年第1期4卷 231-236页

作者： Steffen Hadrich Manuel krebs Armin Hoffmann Arno Klenke Jan Rothhardt Jens Limpert Andreas Tunnermann Friedrich-Schiller-Universitat Jena Institute of Applied PhysicsAbbe Center of PhotonicsAlbert-Einstein-Straße 1507745 JenaGermany Helmholtz-Institute Jena Frobelstieg 307743 JenaGermany Fraunhofer Institute for Applied Optics and Precision engineering Albert-Einstein-Straße 707745 JenaGermany

The process of high harmonic generation(HHg.enables the development of table-top sources of coherent extreme ultraviolet(XUV)*** these are now matured sources,they still mostly rely on bulk laser technology that limits the attainable repetition rate to the low kilohertz ***,many of the emerging applications of such light sources(e.g.,photoelectron spectroscopy and microscopy,coherent diffractive imaging,or frequency metrology in the XUV spectral region)require an increase in the repetition ***,these sources are operated with a multi-MHz repetition rate and deliver a high photon flux *** far,this regime has been solely addressed using passive enhancement cavities together with low energy and high repetition rate ***,a novel route with significantly reduced complexity(omitting the requirement of an external actively stabilized resonator)is demonstrated that achieves the previously mentioned demanding parameters.A krypton-filled Kagome photonic crystal fiber is used for efficient nonlinear compression of 9 μJ,250 fs pulses leading to,7 μJ,31 fs pulses at 10.7 MHz repetition *** compressed pulses are used for HHg in a gas *** attention is devoted to achieving phase-matched(transiently)generation yielding.10^(13) photons s^(-1)(.50 μW)at 27.7 *** new spatially coherent XUV source improved the photon flux by four orders of magnitude for direct multi-MHZ experiments,thus demonstrating the considerable potential of this source.

关键词： coherent extreme ultraviolet sources high average power high harmonic generation nonlinear compression ultrafast laser

Developing a molecular platform for potential carbon dioxide fixing

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Frontiers of Chemical Science and engineering 2010年第2期4卷 236-239页

作者： Mette MIKKeLSeN Mikkel JøRgeNSeN Frederik C.krebs RisøNational Laboratory for Sustainable energy Technical University of DenmarkFrederiksborgvej 399DK-4000 RoskildeDenmark

This paper presents an attempt to develop a new system for fixing carbon dioxide from the *** proposed molecular system has been desig.ed to have the capacity to spontaneously bind CO_(2)from the atmosphere with high *** molecular system is furthermore desig.ed to have the ability to liberate CO_(2)at a later stage in the process,i.e.,in a separate *** liberated CO_(2)presents a carbon neutral way of obtaining pure CO_(2).The proposed molecular system is based on a small stable organic molecule that potentially have two forms:one without bound CO_(2)and one with bound CO_(2).One class of molecules that undergo a reaction compatible with our purposal is the merocyanine dyes that exhibit photochromic *** on this structural class of molecules,a system for the potential fixing of CO_(2)has been developed.

关键词： CO_(2)fixing agent merocyanine dyes CO_(2)liberation

Covering Rearing Tanks Improves Brown Trout growth and Feed Conversion

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Agricultural Sciences 2016年第12期7卷 869-878页

作者： eric krebs Michael e. Barnes Patrick A. Nero South Dakota Department of game Fish and Parks McNenny State Fish Hatchery Spearfish SD USA

Although an important part of the natural environment of fish, overhead cover is usually absent during hatchery rearing. To evaluate the possible influence of overhead cover on juvenile brown trout Salmo trutta hatchery rearing performance, this study compared three different cover treatments: near-full (98%) cover, partial (65%) cover, and no cover (completely open). After 12 weeks of rearing in 1.8 m-diameter circular tanks, total tank weight gain was significantly g.eater and feed conversion ratios were significantly less in tanks of brown trout that were either partially or near-totally covered, in comparison to those tanks that were completely open. The viscerosomatic index, hepatosomatic index, and splenosomatic index values were not significantly different among any of the treatments. Fin condition indices were also not significantly different. The use of either partial or full covers is recommended to maximize brown trout rearing.efficiencies, with full covers providing the additional benefit of preventing fish from jumping out of the tanks.

关键词： Brown Trout Overhead Cover Salmo trutta Circular Tanks

Vertically-Suspended environmental enrichment Improves growth of Landlocked Fall Chinook Salmon during Initial Hatchery Rearing

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Open Journal of Applied Sciences 2020年第11期10卷 725-731页

作者： Nathan Huysman Jill M. Voorhees eric krebs Michael e. Barnes South Dakota game Fish and Parks McNenny State Fish Hatchery Spearfish USA

environmental enrichment has been shown to improve juvenile salmonid growth during hatchery rearing. This study examined the effects of vertically-suspended environmental enrichment starting seven days after feed training and continuing for the next 32 days of landlocked fall Chinook salmon (Oncorhynchus tshawytscha) rearing. At the end of this experiment, final tank weights, gain, percent gain, and feed conversion ratio were all significantly improved in the tanks of salmon with environmental enrichment compared to barren tanks, with a nearly 25% improvement in feed conversion ratio. Individual salmon in tanks with environmental enrichment were significantly longer and weig.ed significantly more than salmon from tanks without enrichment. Specific growth rate was also significantly improved with the use of enrichment. The use of vertically-suspended environmental enrichment to improve growth and rearing.efficiency is recommended during the initial rearing of landlocked fall Chinook salmon.

关键词： Oncorhynchus tshawytscha environmental enrichment Structure Initial Feeding

Thermal Tempering Does Not Impact Rainbow Trout and Brown Trout Survival

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Advances in Bioscience and Biotechnology 2020年第7期11卷 345-353页

作者： Nathan Huysman Jill M. Voorhees eric krebs Michael e. Barnes South Dakota Department of game Fish and Parks McNenny State Fish Hatchery Spearfish SD USA

Hatchery-reared fish are frequently adjusted (tempered) to the hig.er water temperatures present in the water bodies where they are to be stocked. This study was undertaken to determine the necessity of such tempering practices. This study used rainbow trout (Oncorhynchus mykiss) and brown trout (Salmo trutta) reared at 11.2°C. The first two trials for each species were designed to simultaneously determine the upper incipient lethal temperature and 100% lethal temperature over a 14-day period. The third trial for each species evaluated the effects of an exaggerated 12-hour tempering regime on fish survival after placement in elevated water temperatures. After transfer from a water temperature of 11.2°C, no rainbow trout survived at 26°C, and only 50% survived at 25°C. No brown trout survived at 22°C and only 50% at 20°C. Survival of rainbow trout was not improved by the 12-hour tempering regime where water temperatures were slowly increased from 11.2°C to either 25°C or 26°C. Similarly, tempering did not improve brown trout survival at either 20°C or 22°C. These results suggest that tempering is not needed when hatchery-reared trout are reared and stocked at the water temperatures within the range of those used in this study.

关键词： Tempering Rainbow Trout Oncorhynchus mykiss Brown Trout Salmo trutta Temperature

exercise and Structure Improve Juvenile Chinook Salmon Rearing Performance

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Open Journal of Marine Science 2021年第2期11卷 80-91页

作者： Jill M. Voorhees Nathan Huysman eric krebs Michael e. Barnes South Dakota Department of game Fish and Parks McNenny State Fish Hatchery Spearfish SD USA

This experiment evaluated the use of an exercise routine and vertically-sus-pended structure during juvenile landlocked fall Chinook salmon (Oncorhynchus tshawytscha; mean ± SE, initial weight 1.47 ± 0.03 g, total length 56.4 ± 0.4 mm) rearing. Four treatments were used: 1) no exercise routine nor vertically-suspended structure, 2) exercise and structure, 3) exercise and no structure, and 4) no exercise and structure. Water velocities in tanks without exercise were 12 cm/s, where-as the exercise routine consisted of seven days at 12 cm/s followed by seven days at 18 cm/s. The structure was an array consisting of four vertically-suspended aluminum angles. Total tank gain and percent gain were significantly greater after 50 days in the tanks of salmon subjected to the exercise routine and structure compared to the three other treatments. Gain and percent gain were also significantly greater in the tanks receiving structure without exercise compared to tanks with exercise and no structure or tanks with neither exercise nor structure. Feed conversion ratio was signife="font-family:Verdana;">icantly improved in the salmon tanks w

关键词： environmental enrichment Salmonid Oncorhynchus tshawytscha Vertically-Suspended

Influence of Water Velocity and Vertically-Suspended Structures on Rainbow Trout Rearing Performance

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Open Journal of Animal Sciences 2020年第1期10卷 152-161页

作者： Jill M. Voorhees Nathan Huysman eric krebs Michael e. Barnes South Dakota game Fish and Parks McNenny State Fish Hatchery Spearfish South Dakota USA

This study evaluated the effects of two water velocities and three types of vertically-suspended environmental enrichment during the rearing of juvenile rainbow trout (Oncorhynchus mykiss;mean ± Se, initial weight 4 ± 1 g and total length 71 ± 2 mm) in 1.8m diameter circular tanks. The 2 × 3 experimental design used two velocities (12.2 cm·s-1 and 30.5 cm·s-1) and three structural treatments (aluminum rod array, plastic spheres, or no structure). After 116 days, the fish reared without any structure (control) at 30.5 cm·s-1 had significantly lower total tank weight, gain, percent gain, feed conversion ratio, and specific growth rate compared to the other treatments. Similarly, the fish reared with a velocity of 30.5 cm·s-1 without structure were significantly shorter and lighter than those in the other treatments. There was no significant difference in condition factor and relative fin lengths among the treatments. These results indicate that vertically-suspended environmental enrichment may be impacting fish rearing performance by altering tank water velocities.

关键词： environmental enrichment exercise Salmonid Oncorhynchus mykiss

Use of exercise and Structure during Rainbow Trout Rearing

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Open Journal of Applied Sciences 2020年第5期10卷 258-269页

作者： Jill M. Voorhees Nathan Huysman eric krebs Michael e. Barnes Department of game Fish and Parks McNenny State Fish Hatchery Spearfish USA

A combination of two forms of environmental enrichment (in-tank structure and exercise) was evaluated during the hatchery rearing of juvenile rainbow trout Oncorhynchus mykiss. The study used four treatments: 1) neither exercise nor structure, 2) exercise without structure, 3) structure without exercise, and 4) both exercise and structure. Velocities in the unexercised tanks were a constant 12.2 cm-s-1. Velocities in the exercised tanks alternated weekly with one week at 12.2 cm-s-1 followed by a week at 30.5 cm-s-1. Structural enrichment consisted of an array of vertically-suspended aluminum ang.es. The use of either environmental enrichment technique significantly improved final tank weight, gain, percent gain, and specific growth rate. Feed conversion ratio was significantly and positively influenced only by structure, but fish on the exercise routine were overfed. There were no significant interactions between exercise and structure, indicating that each form of environmental enrichment operates independently. The results of this study indicate fish rearing performance can be improved with the addition of either vertically-suspended aluminum ang.es or an exercise routine, but the combination of the two techniques may not be needed to improve rainbow trout growth.

关键词： Routine Velocity Oncorhynchus mykiss Salmonids environmental enrichment