Genomic signatures predict migration and spawning failure in wild Canadian salmon     

Miller KM  Li S  Kaukinen KH  Ginther N  Hammill E  Curtis JM  Patterson DA  Sierocinski T  Donnison L  Pavlidis P  Hinch SG  Hruska KA  Cooke SJ  English KK  Farrell AP 《Science (New York, N.Y.)》2011,331(6014):214-217

Long-term population viability of Fraser River sockeye salmon (Oncorhynchus nerka) is threatened by unusually high levels of mortality as they swim to their spawning areas before they spawn. Functional genomic studies on biopsied gill tissue from tagged wild adults that were tracked through ocean and river environments revealed physiological profiles predictive of successful migration and spawning. We identified a common genomic profile that was correlated with survival in each study. In ocean-tagged fish, a mortality-related genomic signature was associated with a 13.5-fold greater chance of dying en route. In river-tagged fish, the same genomic signature was associated with a 50% increase in mortality before reaching the spawning grounds in one of three stocks tested. At the spawning grounds, the same signature was associated with 3.7-fold greater odds of dying without spawning. Functional analysis raises the possibility that the mortality-related signature reflects a viral infection.  相似文献   

Neuronal GM1 gangliosidosis in a Siamese cat with beta-galactosidase deficiency   总被引：5，自引：0，他引：5  

H J Baker  J R Lindsey  G M McKhann  D F Farrell 《Science (New York, N.Y.)》1971,174(11):838-839

A juvenile Siamese cat with severe, progressive motor disability was shown to have extensive neuronal degeneration caused by accumulation of GM(1) ganglioside. Tissues from brain and kidney were markedly deficient in beta-galactosidase activity. The disease in this cat is thought to be inherited as an autosomal recessive trait, and is strikingly similar to juvenile GM(1) gangliosidosis of children.  相似文献   

Subsurface radar sounding of the south polar layered deposits of Mars     

Plaut JJ  Picardi G  Safaeinili A  Ivanov AB  Milkovich SM  Cicchetti A  Kofman W  Mouginot J  Farrell WM  Phillips RJ  Clifford SM  Frigeri A  Orosei R  Federico C  Williams IP  Gurnett DA  Nielsen E  Hagfors T  Heggy E  Stofan ER  Plettemeier D  Watters TR  Leuschen CJ  Edenhofer P 《Science (New York, N.Y.)》2007,316(5821):92-95

The ice-rich south polar layered deposits of Mars were probed with the Mars Advanced Radar for Subsurface and Ionospheric Sounding on the Mars Express orbiter. The radar signals penetrate deep into the deposits (more than 3.7 kilometers). For most of the area, a reflection is detected at a time delay that is consistent with an interface between the deposits and the substrate. The reflected power from this interface indicates minimal attenuation of the signal, suggesting a composition of nearly pure water ice. Maps were generated of the topography of the basal interface and the thickness of the layered deposits. A set of buried depressions is seen within 300 kilometers of the pole. The thickness map shows an asymmetric distribution of the deposits and regions of anomalous thickness. The total volume is estimated to be 1.6 x 10(6) cubic kilometers, which is equivalent to a global water layer approximately 11 meters thick.  相似文献   

Environmental science. Rethinking hydrogen cars     

Keith DW  Farrell AE 《Science (New York, N.Y.)》2003,301(5631):315-316

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Somatic energy of sockeye salmon Oncorhynchus nerka at the onset of upriver migration: a comparison among ocean climate regimes     

Glenn T. Crossin  Scott G. Hinch  Anthony P. Farrell  David A. Higgs  Michael C. Healey 《Fisheries Oceanography》2004,13(5):345-349

We examined somatic energy patterns in two stocks (Chilko and Early Stuart) of adult Fraser River (British Columbia, Canada) sockeye salmon (Oncorhynchus nerka), collected at the end of their ocean residency, spanning years across different climate regimes. Both stocks had high levels of somatic energy in years with high open ocean productivity (1956, 1957, 2001 and 2002), and relatively low levels in years with poor open ocean productivity (1999 and 2000). For Early Stuart sockeye, energy levels in 1999 and 2000 were approximately 15% lower (～1.5 MJ kg^?1) than that in the 1950s, an amount of energy equivalent to that necessary for migrating 600 km upriver. In recent years (2001 and 2002), energy levels have increased by about 9% for both stocks. Low energy levels at the onset of upriver migration, particularly in years of energetically demanding in‐river conditions, such as high flows or temperatures, are likely to contribute to prespawning and en route mortality in Fraser sockeye.  相似文献   

Effects of cyanide exposure on Dascyllus aruanus, a tropical marine fish species: lethality, anaesthesia and physiological effects     

M. Hanawa  L. Harris  M. Graham  A.P. Farrell  L.I. Bendell-Young 《Aquarium Sciences and Conservation》1998,2(1):21-34

The lethality, anaesthetic and physiological effects of pulsed cyanide (CN-) exposures to a common tropical marine fish Dascyllus aruanus were assessed. Cyanide (25 and 50 mg l-1) was applied as pulses (10, 60 and 120 s) to fish under non-stressed and stressed (by chasing and/or placing fish under hypoxic stress) conditions. Following treatment, the time until recovery and the percent survival were determined. The fish were allowed a 2.5 week recovery period from the treatments at which time four physiological end-points were measured: (1) the blood haemoglobin content, (2) the percent blood O-2 content, (3) the liver rhodonase activity and (4) the liver O2 consumption rate. The greater the CN- concentration and exposure time, the longer the recovery time. Non-stressed fish exposed to 10 s pulses of 25 mg l-1 of CN- fully recovered within 4 min whereas fish exposed for 60 s and 50 mg l-1 of CN- required up to 50 min for full recovery. Exposure for 120 s at 25 and 50 mg l-1 of CN- proved lethal. Under stressed conditions, previously non-lethal exposures (60 s and 50 mg l-1) were lethal. Of the physiological end-points, only the liver O2 consumption rate was indicative of previous CN- exposure. Under non-stressed conditions, pulsed exposures at 25 and 50 mg l-1 of CN- for 10 and 60 s significantly reduced the liver O2 consumption rates (ANOVA; p < 0.05). Under stressed conditions, the liver O2 consumption rates were significantly greater (maximum rates up to 17-fold greater) than the control fish (ANOVA; p < 0.05). We conclude, therefore, that environmentally relevant exposures of CN- can adversely effect fish and this affect can be measured 2.5 weeks post-exposure. Importantly, the combined effects of exposure and stress both increased the mortality and placed an appreciable metabolic load on the fish as indicated by the elevated liver O2 consumption rates. Handling stress in combination with anaesthetic CN- doses could in part explain the delayed mortality reportedly associated with CN- use in the tropical fish trade. The significance of the elevated liver O2 consumption rates on the survival of CN--exposed fish is unknown  相似文献   

The effect of dietary lipid and protein source on the swimming performance, recovery ability and oxygen consumption of Atlantic salmon (Salmo salar)     

C.M. Wilson  E.N. Friesen  A.P. Farrell 《Aquaculture (Amsterdam, Netherlands)》2007,273(4):687-699

The effect of different dietary lipid sources on the athletic health of five groups of Atlantic salmon (Salmo salar) was tested by measuring oxygen consumption rates, prolonged swimming performance, and recovery from exhaustive exercise in a closed circuit respirometer. These groups of fish differed from each other in the source of the supplemental lipid in their diet. The control diet contained 100% anchovy oil, while in the test diets, poultry fat, de-gummed canola oil, or flaxseed oil were used to replace up to 75% fish oil. The composition of the industry diet was a 1:1 blend of anchovy oil and poultry fat, also 50% of the fishmeal protein in this diet was replaced with protein from poultry by-product meal. Despite major differences in dietary lipid and protein composition that altered the lipid composition of the fish, all of our treatment groups performed equally well with respect to their oxygen consumption, swimming performance and recovery ability. Since these swim tests integrated many physiological functions, and collectively represented a sensitive measure of the athletic health of the fish, we concluded that our alternative lipid and protein-based diets represented viable possibilities for salmon farming.  相似文献   

Greenhouse gas flux in a temperate grassland as affected by landform and disturbance     

Matthew Braun  Yuguang Bai  Brian McConkey  Richard Farrell  J. T. Romo  Dan Pennock 《Landscape Ecology》2013,28(4):709-723

Much of the remaining native rangelands in Canada are topographically complex. The flux of greenhouse gases (GHGs) in rangelands of hummocky terrain has not been adequately studied, leaving a gap in the national GHG sources and sinks budget. The objectives of this study were to determine the effects of topography and mowing on carbon dioxide (CO₂), methane (CH₄) and nitrous oxide (N₂O) flux and to correlate these fluxes to abiotic and biotic factors. GHG flux was studied on six landform elements, including north-facing concave and, south-facing concave and convex, upland and depressions, in the Northern Mixedgrass Prairie of Canada over 2 years with mowing being imposed in early spring. GHG fluxes showed strong temporal variations, ranging from 3.0 to 40.4 kg CO₂–C ha^?1 d^?1, 0.1 to 2.6 g N₂O–N ha^?1 d^?1, and ?0.25 to ?0.01 g CH₄–C ha^?1 d^?1. GHG fluxes responded to changes in soil water and soil temperature across the landscape. The largest production of CO₂ was recorded in depression mainly due to its more favourable soil water conditions. Mowing enhanced CO₂ flux more than CH₄ and N₂O fluxes. Dominant plant species varied among the six landform elements, but using plant community type as the direct indicator for GHG emissions in grasslands may not always be reliable when precipitation is low. The net emissions of GHGs from Saskatchewan rangeland was relatively low, but the potential to increase emissions through changes in land management could be high. Our results suggest that in the Mixedgrass Prairie, best management practices for maintaining grassland health such as moderate grazing may also reduce GHG emissions.  相似文献   

Multi-functional landscapes in semi arid environments: implications for biodiversity and ecosystem services   总被引：4，自引：2，他引：2  

P. J. O’Farrell  B. Reyers  D. C. Le Maitre  S. J. Milton  B. Egoh  A. Maherry  C. Colvin  D. Atkinson  W. De Lange  J. N. Blignaut  R. M. Cowling 《Landscape Ecology》2010,25(8):1231-1246

Synergies between biodiversity conservation objectives and ecosystem service management were investigated in the Succulent Karoo biome (83,000 km²) of South Africa, a recognised biodiversity hotspot. Our study complemented a previous biodiversity assessment with an ecosystem service assessment. Stakeholder engagement and expert consultation focussed our investigations on surface water, ground water, grazing and tourism as the key services in this region. The key ecosystem services and service hotspots were modelled and mapped. The congruence between these services, and between biodiversity priorities and ecosystem service priorities, were assessed and considered in relation to known threats. Generally low levels of overlap were found between these ecosystem services, with the exception of surface and ground water which had an 80% overlap. The overlap between ecosystem service hotspots and individual biodiversity priority areas was generally low. Four of the seven priority areas assessed have more than 20% of their areas classified as important for services. In specific cases, particular service levels could be used to justify the management of a specific biodiversity priority area for conservation. Adopting a biome scale hotspot approach to assessing service supply highlighted key management areas. However, it underplayed local level dependence on particular services, not effectively capturing the welfare implications associated with diminishing and limited service provision. We conclude that regional scale (biome level) approaches need to be combined with local level investigations (municipal level). Given the regional heterogeneity and varied nature of the impacts of drivers and threats, diverse approaches are required to steer land management towards sustainable multifunctional landscape strategies.  相似文献   

Conservative versus arthroscopic management for medial coronoid process disease in dogs: a prospective gait evaluation     

Farrell M  Fitzpatrick N 《Veterinary surgery : VS》2012,41(4):541-2; author reply 542-3

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