Niche partitioning among Prochlorococcus ecotypes along ocean-scale environmental gradients     

Johnson ZI  Zinser ER  Coe A  McNulty NP  Woodward EM  Chisholm SW 《Science (New York, N.Y.)》2006,311(5768):1737-1740

Prochlorococcus is the numerically dominant phytoplankter in the oligotrophic oceans, accounting for up to half of the photosynthetic biomass and production in some regions. Here, we describe how the abundance of six known ecotypes, which have small subunit ribosomal RNA sequences that differ by less than 3%, changed along local and basin-wide environmental gradients in the Atlantic Ocean. Temperature was significantly correlated with shifts in ecotype abundance, and laboratory experiments confirmed different temperature optima and tolerance ranges for cultured strains. Light, nutrients, and competitor abundances also appeared to play a role in shaping different distributions.  相似文献   

Interactive effects of nocturnal transpiration and climate change on the root hydraulic redistribution and carbon and water budgets of southern United States pine plantations     

Domec JC  Ogée J  Noormets A  Jouangy J  Gavazzi M  Treasure E  Sun G  McNulty SG  King JS 《Tree physiology》2012,32(6):707-723

Deep root water uptake and hydraulic redistribution (HR) have been shown to play a major role in forest ecosystems during drought, but little is known about the impact of climate change, fertilization and soil characteristics on HR and its consequences on water and carbon fluxes. Using data from three mid-rotation loblolly pine plantations, and simulations with the process-based model MuSICA, this study indicated that HR can mitigate the effects of soil drying and had important implications for carbon uptake potential and net ecosystem exchange (NEE), especially when N fertilization is considered. At the coastal site (C), characterized by deep organic soil, HR increased dry season tree transpiration (T) by up to 40%, and such an increase affected NEE through major changes in gross primary productivity (GPP). Deep-rooted trees did not necessarily translate into a large volume of HR unless soil texture allowed large water potential gradients to occur, as was the case at the sandy site (S). At the Piedmont site (P) characterized by a shallow clay-loam soil, HR was low but not negligible, representing up to 10% of T. In the absence of HR, it was predicted that at the C, S and P sites, annual GPP would have been diminished by 19, 7 and 9%, respectively. Under future climate conditions HR was predicted to be reduced by up to 25% at the C site, reducing the resilience of trees to precipitation deficits. The effect of HR on T and GPP was predicted to diminish under future conditions by 12 and 6% at the C and P sites, respectively. Under future conditions, T was predicted to stay the same at the P site, but to be marginally reduced at the C site and slightly increased at the S site. Future conditions and N fertilization would decrease T by 25% at the C site, by 15% at the P site and by 8% at the S site. At the C and S sites, GPP was estimated to increase by 18% and by >70% under future conditions, respectively, with little effect of N fertilization. At the P site, future conditions would stimulate GPP by only 12%, but future conditions plus N fertilization would increase GPP by 24%. As a consequence, in all sites, water use efficiency was predicted to improve dramatically with future conditions. Modeling the effect of reduced annual precipitation indicated that limited water availability would decrease all carbon fluxes, including NEE and respiration. Our simulations highlight the interactive effects of nutrients and elevated CO(2), and showed that the effect of N fertilization would be greater under future climate conditions.  相似文献   

7500 years of prehistoric footwear from arnold research cave, missouri     

JT Kuttruff  SG DeHart  MJ O'Brien 《Science (New York, N.Y.)》1998,281(5373):72-75

Accelerator mass spectrometer dating of an assemblage of fibrous and leather footwear from Arnold Research Cave in central Missouri documents a long sequence of shoe construction by prehistoric Midwestern peoples, beginning perhaps as early as 8300 calendar years before the present (cal years B.P.). An earlier fibrous sandal form dates from 8325 to 7675 cal years B.P., and later fibrous or leather slip-ons span the period from 5575 to 1070 cal years B.P. The assemblage adds to a growing picture of the highly varied nature of prehistoric footwear production in the United States throughout the Holocene.  相似文献   

Effects of Activin A on the In Vitro Development and mRNA Expression of Bovine Embryos Cultured in Chemically‐Defined Two‐Step Culture Medium     

JE Park  HJ Oh  SG Hong  G Jang  MK Kim  BC Lee 《Reproduction in domestic animals》2010,45(4):585-593

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Identification of permethrin and etofenprox cross‐tolerance in Rhipicephalus sanguineus sensu lato (Acari: Ixodidae)     

Nicholas SG Tucker  Phillip E Kaufman  Emma NI Weeks 《Pest management science》2019,75(10):2794-2801

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Possible Explanation of Fluoride-Induced Respiration in Chlorella pyrenoidosa     

McNulty IB  Lords JL 《Science (New York, N.Y.)》1960,132(3439):1553-1554

Low concentrations of sodium fluoride significantly increase oxygen consumption and total phosphorylated nucleotides in respiring Chlorella pyrenoidosa. Measurements of gas exchange at several pH values indicate that the stimulation is probably related to the undissociated hydrogen fluoride concentration in the suspending media.  相似文献   

Intra- and interspecific phenotypic characteristics of fish-pathogenic Edwardsiella ictaluri and E. tarda   总被引：1，自引：0，他引：1  

Victor S Panangala  Craig A Shoemaker  Shawn T McNulty  Covadonga R Arias  & Phillip H Klesius 《Aquaculture Research》2006,37(1):49-60

Intra‐ and interspecific characteristics of fish‐pathogenic Edwardsiella ictaluri, and E. tarda were determined by numerical analysis of gel electrophoresed protein profiles, fatty acid methyl esters (FAMEs) and immunoblotting. The 18 E. ictaluri isolates revealed a high degree of homogeneity (70% similarity or higher) in their protein profiles and 95% similarity in their FAME, while the nine E. tarda isolates revealed 30% similarity in their protein profiles and 95% similarity in their FAME. Immunoblots probed for antigenic epitopes with goat antiserum produced against E. ictaluri and E. tarda, respectively, revealed that E. ictaluri were more homogeneous compared with the E. tarda isolates. Overall, there was a considerable degree of relatedness between the two species. Our findings suggest that phenotypically E. ictaluri represents a clonal bacterial population structure compared with the less monomorphic E. tarda.  相似文献   

Effect of macrophages and in vitro infection with parainfluenza type 3 and respiratory syncytial viruses on the mitogenic response of bovine lymphocytes.     

B M Adair  H E Bradford  D P Mackie  M S McNulty 《American journal of veterinary research》1992,53(2):225-229

Bovine blood lymphocytes, depleted of macrophages by absorption on plasma-gelatin coated plastic flasks, followed by passage through Sephadex G-10 columns, failed to respond to pokeweed mitogen stimulation. Adherent monocytes or alveolar macrophages added to purified lymphocyte preparations at 10% or less were able to restore the transformation response. Exposure of alveolar macrophages or purified lymphocytes to 2 bovine respiratory syncytial virus strains for 24 hours substantially reduced the transformation response when mixed with uninfected lymphocytes or macrophages. Exposure of alveolar macrophages or purified lymphocytes to 2 bovine parainfluenza type 3 virus strains produced a similar reduction in activity after 48 hours. Heat inactivation of the viruses removed their inhibitory ability. Immunofluorescence studies revealed that both alveolar macrophages and lymphocytes were permissive for parainfluenza type 3 virus, whereas only a small number of alveolar macrophages and lymphocytes were infected with respiratory syncytial virus. The results suggest that both viruses are capable of adversely affecting the interaction between macrophages and lymphocytes, although the mechanisms by which this is achieved may be different.  相似文献   

Production and preliminary characterization of monoclonal antibodies to chicken anemia agent   总被引：2，自引：0，他引：2  

M S McNulty  D P Mackie  D A Pollock  J McNair  D Todd  K A Mawhinney  T J Connor  F McNeilly 《Avian diseases》1990,34(2):352-358

Mice were immunized with partially purified preparations of the Cux-1 isolate of chicken anemia agent (CAA), and their splenocytes were fused with NSO myeloma cells. Three patterns of staining of CAA-infected cells were recognized when the resulting hybridomas were screened by indirect immunofluorescence (IIF). Hybridomas representative of each staining pattern were cloned, and the monoclonal antibodies (MAbs) were characterized. Type 1 staining was indistinguishable from that produced by polyclonal chicken antisera to CAA. Type 2 staining was confined to large nuclear inclusions. Type 3 staining was predominantly nuclear and granular, and differed from type 1 in being more intense and occurring in a higher proportion of nuclei. Three MAbs producing type 1 staining were predominantly Cux-1-specific by IIF; they also reacted to lower titers with the Gifu-1 isolate but not at all with three other CAA isolates. These MAbs had very slight neutralizing activity against Cux-1. Another MAb giving type 1 staining reacted with all CAA isolates tested to high titers in IIF and neutralization tests. MAbs with type 2 and type 3 staining reacted by IIF with all CAA isolates tested but possessed no neutralizing activity. The availability of MABs to CAA should facilitate development of diagnostic tests for the virus.  相似文献   

Leptospires in pig urogenital tracts and fetuses   总被引：3，自引：0，他引：3  

W A Ellis  P J McParland  D G Bryson  M S McNulty 《The Veterinary record》1985,117(3):66-67

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