Concentrations of trace elements in yellow perch (Perca flavescens) from six acidic lakes     

Mark D. Sprenger  Alan W. McIntosh  Stephanie Hoenig 《Water, air, and soil pollution》1988,37(3-4):375-388

Yellow perch (Perca flavescens) were collected from six small acidic lakes in northwestern New Jersey. Analyses of muscle tissue identified a pattern of increased concentrations of Hg in fish from the most acidic lakes; levels of Cd and Pb were greatly elevated in livers of specimens from two of the most acidic lakes. At one site, Sunfish Pond, positive correlations between fish size and Hg levels in muscle and Cd concentrations in livers were detected. In only one case did Hg concentrations in muscle tissue exceed the U.S. FDA action level of 1 μg g^?1 (wet wt).  相似文献   

A map of the interactome network of the metazoan C. elegans   总被引：1，自引：0，他引：1  

Li S  Armstrong CM  Bertin N  Ge H  Milstein S  Boxem M  Vidalain PO  Han JD  Chesneau A  Hao T  Goldberg DS  Li N  Martinez M  Rual JF  Lamesch P  Xu L  Tewari M  Wong SL  Zhang LV  Berriz GF  Jacotot L  Vaglio P  Reboul J  Hirozane-Kishikawa T  Li Q  Gabel HW  Elewa A  Baumgartner B  Rose DJ  Yu H  Bosak S  Sequerra R  Fraser A  Mango SE  Saxton WM  Strome S  Van Den Heuvel S  Piano F  Vandenhaute J  Sardet C  Gerstein M  Doucette-Stamm L  Gunsalus KC  Harper JW  Cusick ME  Roth FP  Hill DE  Vidal M 《Science (New York, N.Y.)》2004,303(5657):540-543

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A persistent oxygen anomaly reveals the fate of spilled methane in the deep Gulf of Mexico   总被引：3，自引：0，他引：3  

Kessler JD  Valentine DL  Redmond MC  Du M  Chan EW  Mendes SD  Quiroz EW  Villanueva CJ  Shusta SS  Werra LM  Yvon-Lewis SA  Weber TC 《Science (New York, N.Y.)》2011,331(6015):312-315

Methane was the most abundant hydrocarbon released during the 2010 Deepwater Horizon oil spill in the Gulf of Mexico. Beyond relevancy to this anthropogenic event, this methane release simulates a rapid and relatively short-term natural release from hydrates into deep water. Based on methane and oxygen distributions measured at 207 stations throughout the affected region, we find that within ~120 days from the onset of release ~3.0 × 10(10) to 3.9 × 10(10) moles of oxygen were respired, primarily by methanotrophs, and left behind a residual microbial community containing methanotrophic bacteria. We suggest that a vigorous deepwater bacterial bloom respired nearly all the released methane within this time, and that by analogy, large-scale releases of methane from hydrate in the deep ocean are likely to be met by a similarly rapid methanotrophic response.  相似文献   

Ecology. Mosquito trials     

James S  Simmons CP  James AA 《Science (New York, N.Y.)》2011,334(6057):771-772

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Human voice recognition depends on language ability     

Perrachione TK  Del Tufo SN  Gabrieli JD 《Science (New York, N.Y.)》2011,333(6042):595

The ability to recognize people by their voice is an important social behavior. Individuals differ in how they pronounce words, and listeners may take advantage of language-specific knowledge of speech phonology to facilitate recognizing voices. Impaired phonological processing is characteristic of dyslexia and thought to be a basis for difficulty in learning to read. We tested voice-recognition abilities of dyslexic and control listeners for voices speaking listeners' native language or an unfamiliar language. Individuals with dyslexia exhibited impaired voice-recognition abilities compared with controls only for voices speaking their native language. These results demonstrate the importance of linguistic representations for voice recognition. Humans appear to identify voices by making comparisons between talkers' pronunciations of words and listeners' stored abstract representations of the sounds in those words.  相似文献   

Biscrolling nanotube sheets and functional guests into yarns     

Lima MD  Fang S  Lepró X  Lewis C  Ovalle-Robles R  Carretero-González J  Castillo-Martínez E  Kozlov ME  Oh J  Rawat N  Haines CS  Haque MH  Aare V  Stoughton S  Zakhidov AA  Baughman RH 《Science (New York, N.Y.)》2011,331(6013):51-55

Multifunctional applications of textiles have been limited by the inability to spin important materials into yarns. Generically applicable methods are demonstrated for producing weavable yarns comprising up to 95 weight percent of otherwise unspinnable particulate or nanofiber powders that remain highly functional. Scrolled 50-nanometer-thick carbon nanotube sheets confine these powders in the galleries of irregular scroll sacks whose observed complex structures are related to twist-dependent extension of Archimedean spirals, Fermat spirals, or spiral pairs into scrolls. The strength and electronic connectivity of a small weight fraction of scrolled carbon nanotube sheet enables yarn weaving, sewing, knotting, braiding, and charge collection. This technology is used to make yarns of superconductors, lithium-ion battery materials, graphene ribbons, catalytic nanofibers for fuel cells, and titanium dioxide for photocatalysis.  相似文献   

Analyzing the effect of stepping stones on target patch colonisation in structured landscapes for Eurasian lynx     

Stephanie Kramer-Schadt  Tobias S. Kaiser  Karin Frank  Thorsten Wiegand 《Landscape Ecology》2011,26(4):501-513

With habitat loss and fragmentation having become two of the major threats to the viability of species, the question of how to manage landscapes for species conservation has attracted much attention. In this context, the planning of stepping stones has been proposed to increase connectivity in fragmented landscapes. We present a simulation study with a neutral landscape approach to assess the effects of stepping stones on colonization success. To that end, we used a spatially explicit, calibrated population model of the European lynx (Lynx lynx) coupled with structured landscapes, in which we could control the landscape parameters of dispersal habitat coverage and contagion, as well as the number and size of stepping stones available for breeding. In general, we found that colonization success increased with increasing habitat coverage but decreased with increasing habitat contagion, while the introduction of stepping stones had significant effects in critical situations. Especially at low to medium dispersal habitat coverage and high disperser mortality, stepping stones had a positive effect on colonization success when they were large enough to produce new dispersers, but negative effects when they were small and located in a way that dispersers would be distracted from more suitable breeding habitat patches. The latter clearly constituted a shading effect and argues for a thorough consideration of the trade-offs related to stepping stone size and location when implementing stepping stones as a conservation measure, especially when the number of individuals of conservation concern is low.  相似文献   

Equid gammaherpesviruses: Persistent bystanders or true pathogens?     

Stephanie A. Brault  N. James MacLachlan 《Veterinary journal (London, England : 1997)》2011,187(1):14-15

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Kinetics of jump landing in agility dogs     

Pfau T  Garland de Rivaz A  Brighton S  Weller R 《Veterinary journal (London, England : 1997)》2011,190(2):278-283

A recent survey reported an increased risk of injury in dogs participating in agility, a competitive canine sport involving different jumping activities. The aim of this study was to quantify the kinetic parameters during jump landing for commonly used obstacle types. It was hypothesised that with increasing obstacle height, the vertical force and vertical and accelerative horizontal impulse will increase as a result of a lengthened aerial phase, a more acute landing angle and the need to convert potential into forwards kinetic energy. Simultaneous kinetic and kinematic data were recorded from 11 competition agility dogs jumping over obstacle combinations of different height and inter-obstacle distance. Speed and landing angle of the second of the two consecutive jumps were successfully controlled by obstacle height and distance between obstacles. Statistical analysis showed differences between obstacles for peak vertical force, vertical impulse and accelerative horizontal impulse (increasing values with more acute landing angles). Extremely high peak vertical force was observed in the forelimbs (4.5 times bodyweight) when landing from a hurdle jump at high speed. Further detailed studies into the consequences for internal limb structures are warranted in order to clarify how this might be related to injury.  相似文献   

Presence and impact of the exercise-induced collapse associated DNM1 mutation in Labrador retrievers and other breeds     

Minor KM  Patterson EE  Keating MK  Gross SD  Ekenstedt KJ  Taylor SM  Mickelson JR 《Veterinary journal (London, England : 1997)》2011,189(2):214-219

The impact of the mutation causing dynamin 1 (DNM1)-associated exercise-induced collapse (d-EIC) was determined in a retrospective genetic survey. The frequency of DNM1 mutant allele carriers in Labrador retrievers from conformation show, field trial/hunt test, pet or service lines ranged from 17.9% to 38.0% and the frequency of homozygous mutant (EE genotype) individuals ranged from 1.8% to 13.6%; 83.6% of these EE Labradors were reported to have collapsed by 4 years of age. DNM1 mutation carriers and EE dogs with a collapse phenotype were also detected in Chesapeake Bay retrievers, Curly-coated retrievers, Boykin spaniels, Pembroke Welsh corgis and mixed breed dogs thought to be Labrador retriever crosses. The DNM1 mutation was not identified in Golden, Flat-coated, or Nova Scotia duck tolling retrievers, or 15 other non-retrieving breeds. Veterinarians and breeders should be aware that the DNM1 EE genotype is not completely penetrant and that d-EIC is a widespread health concern in several very popular breeds, as well as breeds whose genetic similarity to retrievers is not obvious.  相似文献