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Hou Y, Zhao P, Qin H, Mitchell RN, Li Q, Hao W, Zhang M, Ward PD, Yuan J, Deng C, Zhu R. Completing the loop of the Late Jurassic-Early Cretaceous true polar wander event. Nat Commun 2024; 15:2183. [PMID: 38472217 DOI: 10.1038/s41467-024-46466-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Accepted: 02/28/2024] [Indexed: 03/14/2024] Open
Abstract
The reorientation of Earth through rotation of its solid shell relative to its spin axis is known as True polar wander (TPW). It is well-documented at present, but the occurrence of TPW in the geologic past remains controversial. This is especially so for Late Jurassic TPW, where the veracity and dynamics of a particularly large shift remain debated. Here, we report three palaeomagnetic poles at 153, 147, and 141 million years (Myr) ago from the North China craton that document an ~ 12° southward shift in palaeolatitude from 155-147 Myr ago (~1.5° Myr-1), immediately followed by an ~ 10° northward displacement between 147-141 Myr ago (~1.6° Myr-1). Our data support a large round-trip TPW oscillation in the past 200 Myr and we suggest that the shifting back-and-forth of the continents may contribute to the biota evolution in East Asia and the global Jurassic-Cretaceous extinction and endemism.
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Affiliation(s)
- Yifei Hou
- State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, 100029, China
| | - Pan Zhao
- State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, 100029, China.
| | - Huafeng Qin
- State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, 100029, China
| | - Ross N Mitchell
- State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, 100029, China
| | - Qiuli Li
- State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, 100029, China
| | - Wenxing Hao
- State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, 100029, China
| | - Min Zhang
- Key Laboratory of Earth and Planetary Physics, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, 100029, China
| | - Peter D Ward
- Department of Biology, University of Washington, Seattle, WA, 98995, USA
| | - Jie Yuan
- State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, 100029, China
| | - Chenglong Deng
- State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, 100029, China
| | - Rixiang Zhu
- State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, 100029, China
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Barord GJ, Combosch DJ, Giribet G, Landman N, Lemer S, Veloso J, Ward PD. Three new species of Nautilus Linnaeus, 1758 (Mollusca, Cephalopoda) from the Coral Sea and South Pacific. Zookeys 2023; 1143:51-69. [DOI: 10.3897/zookeys.1143.84427] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2022] [Accepted: 12/22/2022] [Indexed: 01/27/2023] Open
Abstract
Nautiloids are a charismatic group of marine molluscs best known for their rich fossil record, but today they are restricted to a handful of species in the family Nautilidae from around the Coral Triangle. Recent genetic work has shown a disconnect between traditional species, originally defined on shell characters, but now with new findings from genetic structure of various Nautilus populations. Here, three new species of Nautilus from the Coral Sea and South Pacific region are formally named using observations of shell and soft anatomical data augmented by genetic information: N. samoaensissp. nov. (from American Samoa), N. vitiensissp. nov. (from Fiji), and N. vanuatuensissp. nov. (from Vanuatu). The formal naming of these three species is timely considering the new and recently published information on genetic structure, geographic occurrence, and new morphological characters, including color patterns of shell and soft part morphology of hood, and will aid in managing these possibly endangered animals. As recently proposed from genetic analyses, there is a strong geographic component affecting taxonomy, with the new species coming from larger island groups that are separated by at least 200 km of deep water (greater than 800 m) from other Nautilus populations and potential habitats. Nautilid shells implode at depths greater than 800 m and depth therefore acts as a biogeographical barrier separating these species. This isolation, coupled with the unique, endemic species in each locale, are important considerations for the conservation management of the extant Nautilus species and populations.
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3
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Shen J, Chen J, Yu J, Algeo TJ, Smith RMH, Botha J, Frank TD, Fielding CR, Ward PD, Mather TA. Mercury evidence from southern Pangea terrestrial sections for end-Permian global volcanic effects. Nat Commun 2023; 14:6. [PMID: 36596767 PMCID: PMC9810726 DOI: 10.1038/s41467-022-35272-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2022] [Accepted: 11/25/2022] [Indexed: 01/04/2023] Open
Abstract
The latest Permian mass extinction (LPME) was triggered by magmatism of the Siberian Traps Large Igneous Province (STLIP), which left an extensive record of sedimentary Hg anomalies at Northern Hemisphere and tropical sites. Here, we present Hg records from terrestrial sites in southern Pangea, nearly antipodal to contemporaneous STLIP activity, providing insights into the global distribution of volcanogenic Hg during this event and its environmental processing. These profiles (two from Karoo Basin, South Africa; two from Sydney Basin, Australia) exhibit significant Hg enrichments within the uppermost Permian extinction interval as well as positive Δ199Hg excursions (to ~0.3‰), providing evidence of long-distance atmospheric transfer of volcanogenic Hg. These results demonstrate the far-reaching effects of the Siberian Traps as well as refine stratigraphic placement of the LPME interval in the Karoo Basin at a temporal resolution of ~105 years based on global isochronism of volcanogenic Hg anomalies.
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Affiliation(s)
- Jun Shen
- State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Wuhan, Hubei, 430074, People's Republic of China.
| | - Jiubin Chen
- Institute of Surface-Earth System Science, Tianjin University, Tianjin, 300072, People's Republic of China
| | - Jianxin Yu
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, Hubei, 430074, People's Republic of China
| | - Thomas J Algeo
- State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Wuhan, Hubei, 430074, People's Republic of China.,State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, Hubei, 430074, People's Republic of China.,Department of Geosciences, University of Cincinnati, Cincinnati, OH, 45221-0013, USA
| | - Roger M H Smith
- Evolutionary Studies Institute, University of the Witwatersrand, Johannesburg, 2050, South Africa.,Iziko South African Museum, PO Box 61, Cape Town, 8000, South Africa
| | - Jennifer Botha
- Evolutionary Studies Institute, University of the Witwatersrand, Johannesburg, 2050, South Africa.,National Museum, PO Box 266, Bloemfontein, 9300, South Africa
| | - Tracy D Frank
- Department of Earth Sciences, University of Connecticut, Storrs, CT, 06269, USA
| | | | - Peter D Ward
- Department of Biology, University of Washington, Seattle, WA, 98195-1800, USA
| | - Tamsin A Mather
- Department of Earth Sciences, University of Oxford, South Parks Road, Oxford, OX1 3AN, UK
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4
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Combosch DJ, Lemer S, Ward PD, Landman NH, Giribet G. Genomic signatures of evolution in Nautilus-An endangered living fossil. Mol Ecol 2017; 26:5923-5938. [PMID: 28872211 DOI: 10.1111/mec.14344] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Revised: 08/15/2017] [Accepted: 08/24/2017] [Indexed: 12/25/2022]
Abstract
Living fossils are survivors of previously more diverse lineages that originated millions of years ago and persisted with little morphological change. Therefore, living fossils are model organisms to study both long-term and ongoing adaptation and speciation processes. However, many aspects of living fossil evolution and their persistence in the modern world remain unclear. Here, we investigate three major aspects of the evolutionary history of living fossils: cryptic speciation, population genetics and effective population sizes, using members of the genera Nautilus and Allonautilus as classic examples of true living fossils. For this, we analysed genomewide ddRAD-Seq data for all six currently recognized nautiloid species throughout their distribution range. Our analyses identified three major allopatric Nautilus clades: a South Pacific clade, subdivided into three subclades with no signs of admixture between them; a Coral Sea clade, consisting of two genetically distinct populations with significant admixture; and a widespread Indo-Pacific clade, devoid of significant genetic substructure. Within these major clades, we detected five Nautilus groups, which likely correspond to five distinct species. With the exception of Nautilus macromphalus, all previously described species are at odds with genomewide data, testifying to the prevalence of cryptic species among living fossils. Detailed FST analyses further revealed significant genome-wide and locus-specific signatures of selection between species and differentiated populations, which is demonstrated here for the first time in a living fossil. Finally, approximate Bayesian computation (ABC) simulations suggest large effective population sizes, which may explain the low levels of population differentiation commonly observed in living fossils.
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Affiliation(s)
- David J Combosch
- Museum of Comparative Zoology & Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, USA.,Marine Laboratory, University of Guam, Mangilao, GU, USA
| | - Sarah Lemer
- Museum of Comparative Zoology & Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, USA.,Marine Laboratory, University of Guam, Mangilao, GU, USA
| | - Peter D Ward
- Department of Biology, University of Washington, Seattle, WA, USA
| | - Neil H Landman
- Division of Paleontology, American Museum of Natural History, New York, NY, USA
| | - Gonzalo Giribet
- Museum of Comparative Zoology & Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, USA
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Vandepas LE, Dooley FD, Barord GJ, Swalla BJ, Ward PD. A revisited phylogeography of Nautilus pompilius. Ecol Evol 2016; 6:4924-35. [PMID: 27547323 PMCID: PMC4979717 DOI: 10.1002/ece3.2248] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Revised: 05/09/2016] [Accepted: 05/16/2016] [Indexed: 01/31/2023] Open
Abstract
The cephalopod genus Nautilus is considered a "living fossil" with a contested number of extant and extinct species, and a benthic lifestyle that limits movement of animals between isolated seamounts and landmasses in the Indo-Pacific. Nautiluses are fished for their shells, most heavily in the Philippines, and these fisheries have little monitoring or regulation. Here, we evaluate the hypothesis that multiple species of Nautilus (e.g., N. belauensis, N. repertus and N. stenomphalus) are in fact one species with a diverse phenotypic and geologic range. Using mitochondrial markers, we show that nautiluses from the Philippines, eastern Australia (Great Barrier Reef), Vanuatu, American Samoa, and Fiji fall into distinct geographical clades. For phylogenetic analysis of species complexes across the range of nautilus, we included sequences of Nautilus pompilius and other Nautilus species from GenBank from localities sampled in this study and others. We found that specimens from Western Australia cluster with samples from the Philippines, suggesting that interbreeding may be occurring between those locations, or that there is limited genetic drift due to large effective population sizes. Intriguingly, our data also show that nautilus identified in other studies as N. belauensis, N. stenomphalus, or N. repertus are likely N. pompilius displaying a diversity of morphological characters, suggesting that there is significant phenotypic plasticity within N. pompilius.
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Affiliation(s)
- Lauren E. Vandepas
- Friday Harbor LaboratoriesBiology DepartmentUniversity of WashingtonSeattleWashington
| | - Frederick D. Dooley
- Friday Harbor LaboratoriesBiology DepartmentUniversity of WashingtonSeattleWashington
| | - Gregory J. Barord
- Department of BiologyGraduate CenterCity University of New YorkNew York CityNew York10016
- Department of BiologyBrooklyn CollegeCity University of New YorkBrooklynNew York11210
| | - Billie J. Swalla
- Friday Harbor LaboratoriesBiology DepartmentUniversity of WashingtonSeattleWashington
| | - Peter D. Ward
- Friday Harbor LaboratoriesBiology DepartmentUniversity of WashingtonSeattleWashington
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6
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Barord GJ, Dooley F, Dunstan A, Ilano A, Keister KN, Neumeister H, Preuss T, Schoepfer S, Ward PD. Comparative population assessments of Nautilus sp. in the Philippines, Australia, Fiji, and American Samoa using baited remote underwater video systems. PLoS One 2014; 9:e100799. [PMID: 24956107 PMCID: PMC4067400 DOI: 10.1371/journal.pone.0100799] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Accepted: 05/29/2014] [Indexed: 12/02/2022] Open
Abstract
The extant species of Nautilus and Allonautilus (Cephalopoda) inhabit fore-reef slope environments across a large geographic area of the tropical western Pacific and eastern Indian Oceans. While many aspects of their biology and behavior are now well-documented, uncertainties concerning their current populations and ecological role in the deeper, fore-reef slope environments remain. Given the historical to current day presence of nautilus fisheries at various locales across the Pacific and Indian Oceans, a comparative assessment of the current state of nautilus populations is critical to determine whether conservation measures are warranted. We used baited remote underwater video systems (BRUVS) to make quantitative photographic records as a means of estimating population abundance of Nautilus sp. at sites in the Philippine Islands, American Samoa, Fiji, and along an approximately 125 km transect on the fore reef slope of the Great Barrier Reef from east of Cairns to east of Lizard Island, Australia. Each site was selected based on its geography, historical abundance, and the presence (Philippines) or absence (other sites) of Nautilus fisheries The results from these observations indicate that there are significantly fewer nautiluses observable with this method in the Philippine Islands site. While there may be multiple possibilities for this difference, the most parsimonious is that the Philippine Islands population has been reduced due to fishing. When compared to historical trap records from the same site the data suggest there have been far more nautiluses at this site in the past. The BRUVS proved to be a valuable tool to measure Nautilus abundance in the deep sea (300–400 m) while reducing our overall footprint on the environment.
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Affiliation(s)
- Gregory J. Barord
- Department of Biology, Graduate Center, City University of New York, New York, New York, United States of America
- Department of Biology, Brooklyn College, City University of New York, Brooklyn, New York, United States of America
- * E-mail:
| | - Frederick Dooley
- Department of Biology, University of Washington, Seattle, Washington, United States of America
| | - Andrew Dunstan
- School of Biomedical Sciences, University of Queensland, Brisbane St. Lucia, Queensland, Australia
| | - Anthony Ilano
- Department of Biology, University of San Carlos, Cebu City, Cebu, Philippines
| | - Karen N. Keister
- Department of Biology, Alaskan Observers Incorporated, Seattle, Washington, United States of America
| | - Heike Neumeister
- Department of Psychology, Hunter College, City University of New York, New York, New York, United States of America
| | - Thomas Preuss
- Department of Psychology, Hunter College, City University of New York, New York, New York, United States of America
| | - Shane Schoepfer
- Department of Biology, University of Washington, Seattle, Washington, United States of America
- Department of Earth and Space Sciences, University of Washington, Seattle, Washington, United States of America
| | - Peter D. Ward
- Department of Biology, University of Washington, Seattle, Washington, United States of America
- Department of Earth and Space Sciences, University of Washington, Seattle, Washington, United States of America
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Pietersen ANJ, Ward PD, Hagger-Vaughan N, Wiggins J, Jefferys JGR, Vreugdenhil M. Transition between fast and slow gamma modes in rat hippocampus area CA1 in vitro is modulated by slow CA3 gamma oscillations. J Physiol 2013; 592:605-20. [PMID: 24277864 DOI: 10.1113/jphysiol.2013.263889] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Hippocampal gamma oscillations have been associated with cognitive functions including navigation and memory encoding/retrieval. Gamma oscillations in area CA1 are thought to depend on the oscillatory drive from CA3 (slow gamma) or the entorhinal cortex (fast gamma). Here we show that the local CA1 network can generate its own fast gamma that can be suppressed by slow gamma-paced inputs from CA3. Moderate acetylcholine receptor activation induces fast (45 ± 1 Hz) gamma in rat CA1 minislices and slow (33 ± 1 Hz) gamma in CA3 minislices in vitro. Using pharmacological tools, current-source density analysis and intracellular recordings from pyramidal cells and fast-spiking stratum pyramidale interneurons, we demonstrate that fast gamma in CA1 is of the pyramidal-interneuron network gamma (PING) type, with the firing of principal cells paced by recurrent perisomal IPSCs. The oscillation frequency was only weakly dependent on IPSC amplitude, and decreased to that of CA3 slow gamma by reducing IPSC decay rate or reducing interneuron activation through tonic inhibition of interneurons. Fast gamma in CA1 was replaced by slow CA3-driven gamma in unlesioned slices, which could be mimicked in CA1 minislices by sub-threshold 35 Hz Schaffer collateral stimulation that activated fast-spiking interneurons but hyperpolarised pyramidal cells, suggesting that slow gamma frequency CA3 outputs can suppress the CA1 fast gamma-generating network by feed-forward inhibition and replaces it with a slower gamma oscillation driven by feed-forward inhibition. The transition between the two gamma oscillation modes in CA1 might allow it to alternate between effective communication with the medial entorhinal cortex and CA3, which have different roles in encoding and recall of memory.
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Affiliation(s)
- Alexander N J Pietersen
- Neuronal Networks group, School of Clinical and Experimental Medicine, University of Birmingham, B15 2TT, Birmingham, UK.
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Vilhena DA, Harris EB, Bergstrom CT, Maliska ME, Ward PD, Sidor CA, Strömberg CAE, Wilson GP. Bivalve network reveals latitudinal selectivity gradient at the end-Cretaceous mass extinction. Sci Rep 2013. [PMCID: PMC3646391 DOI: 10.1038/srep01790] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Biogeographic patterns of survival help constrain the causal factors responsible for mass extinction. To test whether biogeography influenced end-Cretaceous (K-Pg) extinction patterns, we used a network approach to delimit biogeographic units (BUs) above the species level in a global Maastrichtian database of 329 bivalve genera. Geographic range is thought to buffer taxa from extinction, but the number of BUs a taxon occurred in superseded geographic range as an extinction predictor. Geographically, we found a latitudinal selectivity gradient for geographic range in the K-Pg, such that higher latitude BUs had lower extinction than expected given the geographic ranges of the genera, implying that (i) high latitude BUs were more resistant to extinction, (ii) the intensity of the K-Pg kill mechanism declined with distance from the tropics, or (iii) both. Our results highlight the importance of macroecological structure in constraining causal mechanisms of extinction and estimating extinction risk of taxa.
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Dooley FD, Nair SP, Ward PD. Increased growth and germination success in plants following hydrogen sulfide administration. PLoS One 2013; 8:e62048. [PMID: 23614010 PMCID: PMC3629089 DOI: 10.1371/journal.pone.0062048] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2012] [Accepted: 03/18/2013] [Indexed: 11/19/2022] Open
Abstract
This study presents a novel way of enhancing plant growth through the use of a non-petroleum based product. We report here that exposing either roots or seeds of multicellular plants to extremely low concentrations of dissolved hydrogen sulfide at any stage of life causes statistically significant increases in biomass including higher fruit yield. Individual cells in treated plants were smaller (~13%) than those of controls. Germination success and seedling size increased in, bean, corn, wheat, and pea seeds while time to germination decreases. These findings indicated an important role of H2S as a signaling molecule that can increase the growth rate of all species yet tested. The increased crop yields reported here has the potential to effect the world's agricultural output.
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Affiliation(s)
- Frederick D Dooley
- Department of Biology, University of Washington, Seattle, Washington, United States of America.
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Smith DJ, Timonen HJ, Jaffe DA, Griffin DW, Birmele MN, Perry KD, Ward PD, Roberts MS. Intercontinental dispersal of bacteria and archaea by transpacific winds. Appl Environ Microbiol 2013; 79:1134-9. [PMID: 23220959 PMCID: PMC3568602 DOI: 10.1128/aem.03029-12] [Citation(s) in RCA: 125] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2012] [Accepted: 11/20/2012] [Indexed: 11/20/2022] Open
Abstract
Microorganisms are abundant in the upper atmosphere, particularly downwind of arid regions, where winds can mobilize large amounts of topsoil and dust. However, the challenge of collecting samples from the upper atmosphere and reliance upon culture-based characterization methods have prevented a comprehensive understanding of globally dispersed airborne microbes. In spring 2011 at the Mt. Bachelor Observatory in North America (2.8 km above sea level), we captured enough microbial biomass in two transpacific air plumes to permit a microarray analysis using 16S rRNA genes. Thousands of distinct bacterial taxa spanning a wide range of phyla and surface environments were detected before, during, and after each Asian long-range transport event. Interestingly, the transpacific plumes delivered higher concentrations of taxa already in the background air (particularly Proteobacteria, Actinobacteria, and Firmicutes). While some bacterial families and a few marine archaea appeared for the first and only time during the plumes, the microbial community compositions were similar, despite the unique transport histories of the air masses. It seems plausible, when coupled with atmospheric modeling and chemical analysis, that microbial biogeography can be used to pinpoint the source of intercontinental dust plumes. Given the degree of richness measured in our study, the overall contribution of Asian aerosols to microbial species in North American air warrants additional investigation.
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Affiliation(s)
- David J Smith
- University of Washington, Department of Biology, Seattle, Washington, USA.
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11
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Abstract
Vertical depth migrations into shallower waters at night by the chambered cephalopod Nautilus were first hypothesized early in the early 20th Century. Subsequent studies have supported the hypothesis that Nautilus spend daytime hours at depth and only ascend to around 200 m at night. Here we challenge this idea of a universal Nautilus behavior. Ultrasonic telemetry techniques were employed to track eleven specimens of Nautilus pompilius for variable times ranging from one to 78 days at Osprey Reef, Coral Sea, Australia. To supplement these observations, six remotely operated vehicle (ROV) dives were conducted at the same location to provide 29 hours of observations from 100 to 800 meter depths which sighted an additional 48 individuals, including five juveniles, all deeper than 489 m. The resulting data suggest virtually continuous, nightly movement between depths of 130 to 700 m, with daytime behavior split between either virtual stasis in the relatively shallow 160–225 m depths or active foraging in depths between 489 to 700 m. The findings also extend the known habitable depth range of Nautilus to 700 m, demonstrate juvenile distribution within the same habitat as adults and document daytime feeding behavior. These data support a hypothesis that, contrary to previously observed diurnal patterns of shallower at night than day, more complex vertical movement patterns may exist in at least this, and perhaps all other Nautilus populations. These are most likely dictated by optimal feeding substrate, avoidance of daytime visual predators, requirements for resting periods at 200 m to regain neutral buoyancy, upper temperature limits of around 25°C and implosion depths of 800 m. The slope, terrain and biological community of the various geographically separated Nautilus populations may provide different permutations and combinations of the above factors resulting in preferred vertical movement strategies most suited for each population.
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Affiliation(s)
- Andrew J Dunstan
- School of Biomedical Science, University of Queensland, Brisbane, Queensland, Australia.
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12
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Dunstan AJ, Ward PD, Marshall NJ. Nautilus pompilius life history and demographics at the Osprey Reef Seamount, Coral Sea, Australia. PLoS One 2011; 6:e16312. [PMID: 21347356 PMCID: PMC3037366 DOI: 10.1371/journal.pone.0016312] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2010] [Accepted: 12/08/2010] [Indexed: 11/23/2022] Open
Abstract
Nautiloids are the subject of speculation as to their threatened status arising from the impacts of targeted fishing for the ornamental shell market. Life history knowledge is essential to understand the susceptibility of this group to overfishing and to the instigation of management frameworks. This study provides a comprehensive insight into the life of Nautilus in the wild. At Osprey Reef from 1998–2008, trapping for Nautilus was conducted on 354 occasions, with 2460 individuals of one species, Nautilus pompilius, captured and 247 individuals recaptured. Baited remote underwater video systems (BRUVS) were deployed on 15 occasions and six remotely operated vehicle (ROV) dives from 100–800 m were conducted to record Nautilus presence and behavior. Maturity, sex and size data were recorded, while measurements of recaptured individuals allowed estimation of growth rates to maturity, and longevity beyond maturity. We found sexual dimorphism in size at maturity (males: 131.9±SD = 2.6 mm; females: 118.9±7.5 mm shell diameter) in a population dominated by mature individuals (58%). Mean growth rates of 15 immature recaptured animals were 0.061±0.023 mm day−1 resulting in an estimate of around 15.5 years to maturation. Recaptures of mature animals after five years provide evidence of a lifespan exceeding 20 years. Juvenile Nautilus pompilius feeding behavior was recorded for the first time within the same depth range (200–610 m) as adults. Our results provide strong evidence of a K-selected life history for Nautilus from a detailed study of a ‘closed’ wild population. In conjunction with population size and density estimates established for the Osprey Reef Nautilus, this work allows calculations for sustainable catch and provides mechanisms to extrapolate these findings to other extant nautiloid populations (Nautilus and Allonautilus spp.) throughout the Indo-Pacific.
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Affiliation(s)
- Andrew J Dunstan
- School of Biomedical Science, University of Queensland, Brisbane, Queensland, Australia.
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13
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Abstract
Hallucinations, a hallmark of psychosis, can be induced by the psychotomimetic N-methyl-D-aspartic acid (NMDA) receptor antagonists, ketamine and phencyclidine (PCP), and are associated with hypersynchronization in the γ-frequency band, but it is unknown how reduced interneuron activation associated with NMDA receptor hypofunction can cause hypersynchronization or distorted perception. Low-frequency γ-oscillations (LFγ) and high-frequency γ-oscillations (HFγ) serve different aspects of perception. In this study, we test whether ketamine and PCP affect the interactions between HFγ and LFγ in the rat visual cortex in vitro. In slices of the rat visual cortex, kainate and carbachol induced LFγ (∼ 34 Hz at 32°C) in layer V and HFγ (∼ 54 Hz) in layer III of the same cortical column. In controls, HFγ and LFγ were independent, and pyramidal neurons recorded in layer III were entrained by HFγ, but not by LFγ. Sub-anesthetic concentrations of ketamine selectively decelerated HFγ by 22 Hz (EC(50)=2.7 μM), to match the frequency of LFγ in layer V. This caused phase coupling of the two γ-oscillations, increased spatial coherence in layer III, and entrained the firing of layer III pyramidal neurons by LFγ in layer V. PCP similarly decelerated HFγ by 22 Hz (EC(50)=0.16 μM), causing cross-layer phase coupling of γ-oscillations. Selective NMDA receptor antagonism, selective NR2B subunit-containing receptor antagonism, and reduced D-serine levels caused a similar selective deceleration of HFγ, whereas increasing NMDA receptor activation through exogenous NMDA, D-serine, or mGluR group 1 agonism selectively accelerated HFγ. The NMDA receptor hypofunction-induced phase coupling of the normally independent γ-generating networks is likely to cause abnormal cross-layer interactions, which may distort perceptions due to aberrant matching of top-down information with bottom-up information. If decelerated HFγ and subsequent cross-layer synchronization also underlie pathological psychosis, acceleration of HFγ could be the target for improved antipsychotic therapy.
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Affiliation(s)
- Himashi Anver
- Neuronal Networks Group, School of Clinical and Experimental Medicine, University of Birmingham, Birmingham, United Kingdom
| | - Peter D Ward
- Neuronal Networks Group, School of Clinical and Experimental Medicine, University of Birmingham, Birmingham, United Kingdom
| | - Andor Magony
- Neuronal Networks Group, School of Clinical and Experimental Medicine, University of Birmingham, Birmingham, United Kingdom
| | - Martin Vreugdenhil
- Neuronal Networks Group, School of Clinical and Experimental Medicine, University of Birmingham, Birmingham, United Kingdom,Neuronal Networks Group, School of Clinical and Experimental Medicine, University of Birmingham, Birmingham B15 2TT, United Kingdom. Tel: +44 121 4147629; Fax: +44 121 4147625; E-mail:
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Oke OO, Magony A, Anver H, Ward PD, Jiruska P, Jefferys JGR, Vreugdenhil M. High-frequency gamma oscillations coexist with low-frequency gamma oscillations in the rat visual cortex in vitro. Eur J Neurosci 2010; 31:1435-45. [PMID: 20384769 DOI: 10.1111/j.1460-9568.2010.07171.x] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Synchronization of neuronal activity in the visual cortex at low (30-70 Hz) and high gamma band frequencies (> 70 Hz) has been associated with distinct visual processes, but mechanisms underlying high-frequency gamma oscillations remain unknown. In rat visual cortex slices, kainate and carbachol induce high-frequency gamma oscillations (fast-gamma; peak frequency approximately 80 Hz at 37 degrees C) that can coexist with low-frequency gamma oscillations (slow-gamma; peak frequency approximately 50 Hz at 37 degrees C) in the same column. Current-source density analysis showed that fast-gamma was associated with rhythmic current sink-source sequences in layer III and slow-gamma with rhythmic current sink-source sequences in layer V. Fast-gamma and slow-gamma were not phase-locked. Slow-gamma power fluctuations were unrelated to fast-gamma power fluctuations, but were modulated by the phase of theta (3-8 Hz) oscillations generated in the deep layers. Fast-gamma was spatially less coherent than slow-gamma. Fast-gamma and slow-gamma were dependent on gamma-aminobutyric acid (GABA)(A) receptors, alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors and gap-junctions, their frequencies were reduced by thiopental and were weakly dependent on cycle amplitude. Fast-gamma and slow-gamma power were differentially modulated by thiopental and adenosine A(1) receptor blockade, and their frequencies were differentially modulated by N-methyl-D-aspartate (NMDA) receptors, GluK1 subunit-containing receptors and persistent sodium currents. Our data indicate that fast-gamma and slow-gamma both depend on and are paced by recurrent inhibition, but have distinct pharmacological modulation profiles. The independent co-existence of fast-gamma and slow-gamma allows parallel processing of distinct aspects of vision and visual perception. The visual cortex slice provides a novel in vitro model to study cortical high-frequency gamma oscillations.
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Affiliation(s)
- Olaleke O Oke
- Neuronal Networks, School of Clinical and Experimental Medicine, University of Birmingham, Birmingham, UK
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Affiliation(s)
- Robert A Berner
- Department of Geology and Geophysics, Yale University, New Haven, CT 06520, USA.
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Affiliation(s)
- Peter D Ward
- University of Washington, Biology Department, Earth and Space Sciences Division, USA
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Chaves AA, Keller WJ, O'Sullivan S, Williams MA, Fitzgerald LE, McPherson HE, Goykhman D, Ward PD, Hoe CM, Mixson L, Briscoe RJ. Cardiovascular monkey telemetry: Sensitivity to detect QT interval prolongation. J Pharmacol Toxicol Methods 2006; 54:150-8. [PMID: 16679034 DOI: 10.1016/j.vascn.2006.03.004] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2006] [Accepted: 03/16/2006] [Indexed: 11/15/2022]
Abstract
INTRODUCTION Preclinical evaluation of delayed ventricular repolarization manifests electrocardiographically as QT interval prolongation and is routinely used as an indicator of potential risk for pro-arrhythmia (potential to cause Torsades de Pointes) of novel human pharmaceuticals. In accordance with ICH S7A and S7B guidelines we evaluated the sensitivity and validity of the monkey telemetry model as a preclinical predictor of QT interval prolongation in humans. METHODS Cardiovascular monitoring was conducted for 2 h pre-dose and 24 h post-dosing with Moxifloxacin (MOX), with a toxicokinetic (TK) evaluation in a separate group of monkeys. In both studies, MOX was administered orally by gavage in 0.5% methylcellulose at 0, 10, 30, 100, 175 mg/kg. Each monkey received all 5 doses using a dose-escalation paradigm. Inherent variability of the model was assessed with administration of vehicle alone for 4 days in all 4 monkeys (0.5% methylcellulose in deionized water). RESULTS MOX had no significant effect on mean arterial pressure, heart rate, PR or QRS intervals. MOX produced significant dose-related increases in QTc at doses of 30 (Cmax=5.5+/-0.6 microM), 100 (Cmax=16.5+/-1.6 microM), and 175 (Cmax=17.3+/-0.7 microM) mg/kg with peak increases of 22 (8%), 27 (10%), and 47 (18%) ms, respectively (p<or=0.05; compared to vehicle). DISCUSSION In conclusion, we have developed a reproducible, sensitive and reliable primate telemetry model in rhesus monkeys, which exhibits low inherent intra-animal variability and high sensitivity to detect small but significant increases in QT/QTc interval (approximately 4%) with MOX in the same range of therapeutic plasma concentrations attained in humans. Therefore, the primate telemetry model should be considered an important preclinical predictor of QT prolongation of novel human pharmaceuticals.
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Affiliation(s)
- A A Chaves
- Safety Assessment, Merck Research Laboratories, P.O. Box 4, West Point, PA 19486, United States
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Ward PD, Buick R, Erwin DH. Response to Comment on "Abrupt and Gradual Extinction Among Late Permian Land Vertebrates in the Karoo Basin, South Africa". Science 2005. [DOI: 10.1126/science.1110538] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- Peter D. Ward
- Department of Biology, University of Washington, Seattle, WA 98195, USA
| | - Roger Buick
- Department of Earth and Space Sciences, University of Washington
| | - Douglas H. Erwin
- Department of Paleobiology, MRC-121, Smithsonian Institution, Washington, DC 20013, USA
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Abstract
A catastrophic extinction occurred at the end of the Permian Period. However, baseline extinction rates appear to have been elevated even before the final catastrophe, suggesting sustained environmental degradation. For terrestrial vertebrates during the Late Permian, the combination of a drop in atmospheric oxygen plus climate warming would have induced hypoxic stress and consequently compressed altitudinal ranges to near sea level. Our simulations suggest that the magnitude of altitudinal compression would have forced extinctions by reducing habitat diversity, fragmenting and isolating populations, and inducing a species-area effect. It also might have delayed ecosystem recovery after the mass extinction.
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Affiliation(s)
- Raymond B Huey
- Department of Biology, University of Washington, Box 351800, Seattle, WA 98195, USA.
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Ward PD, Botha J, Buick R, De Kock MO, Erwin DH, Garrison GH, Kirschvink JL, Smith R. Abrupt and gradual extinction among Late Permian land vertebrates in the Karoo basin, South Africa. Science 2005; 307:709-14. [PMID: 15661973 DOI: 10.1126/science.1107068] [Citation(s) in RCA: 247] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The Karoo basin of South Africa exposes a succession of Upper Permian to Lower Triassic terrestrial strata containing abundant terrestrial vertebrate fossils. Paleomagnetic/magnetostratigraphic and carbon-isotope data allow sections to be correlated across the basin. With this stratigraphy, the vertebrate fossil data show a gradual extinction in the Upper Permian punctuated by an enhanced extinction pulse at the Permian-Triassic boundary interval, particularly among the dicynodont therapsids, coinciding with negative carbon-isotope anomalies.
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Affiliation(s)
- Peter D Ward
- Department of Biology, University of Washington, Seattle, WA 98195, USA.
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Abstract
The results presented in this study establish an association between phospholipase C-beta (PLC-beta) and tight junction permeability across Madin-Darby canine kidney (MDCK) cell monolayers, an in vitro model for epithelial tissue. These results further show that PLC-beta modulates tight junction permeability by affecting actin filament organization. Hexadecylphosphocholine (HPC) inhibited PLC-beta and increased tight junction permeability in MDCK cells. Interestingly, the analogs of HPC, a series of alkylphosphocholines containing various lengths of linear alkyl chains, inhibited PLC-beta and increased tight junction permeability with a wide range of potency. The potency of alkylphosphocholines as enhancers of tight junction permeability significantly correlated (p < 0.05) with their potency as PLC-beta inhibitors. U73122, a steroid derivative that is structurally unrelated to alkylphosphocholines, inhibited PLC-beta and increased tight junction permeability with potencies that fit into the correlation observed for the alkylphosphocholine series. U73122 and HPC induced disorganization of actin filaments in MDCK cell monolayers. The potencies to cause disorganization of actin filaments were consistent with the potencies of these agents as inhibitors of PLC-beta and enhancers of tight junction permeability. Furthermore, ATP, an activator of PLC-beta, attenuated U73122-induced increase in tight junction permeability as well as disorganization of actin filaments. These results provide strong evidence that PLC-beta inhibition leads to increased tight junction permeability across MDCK cell monolayers through disorganization of actin filaments.
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Affiliation(s)
- Peter D Ward
- Department of Pharmacology, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
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Ward PD, Klein RR, Troutman MD, Desai S, Thakker DR. Phospholipase C-gamma modulates epithelial tight junction permeability through hyperphosphorylation of tight junction proteins. J Biol Chem 2002; 277:35760-5. [PMID: 12101180 DOI: 10.1074/jbc.m203134200] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Phospholipase C-gamma (PLC-gamma) is stimulated by epidermal growth factor via activation of the epidermal growth factor receptors. The PLC inhibitor, 3-nitrocoumarin (3-NC), selectively inhibited PLC-gamma in Madin-Darby canine kidney cells without affecting the activity of PLC-beta. In contrast, inhibitors of PLC-beta, hexadecylphosphocholine and, had no effect on the activity of PLC-gamma. Inhibition of PLC-gamma by 3-NC was associated with an increase in tight junction permeability across Madin-Darby canine kidney cell monolayers, as evidenced by 3-NC-induced decrease in transepithelial electrical resistance and increase in mannitol flux over a concentration range that was inhibitory to PLC-gamma. An analog of 3-NC, 7-hydroxy-3-NC (7-OH-3-NC), which was inactive as an inhibitor of PLC-gamma, also had no effect on tight junction permeability. Treatment with 3-NC caused punctate disruption in the cortical actin filaments. The PLC-gamma inhibitor, 3-NC, but not the inactive analog, 7-OH-3-NC, caused hyperphosphorylation of the tight junction proteins, occludin, ZO-1, and ZO-2. The serine/threonine kinase inhibitor, staurosporine (50-200 nm), significantly attenuated 3-NC-induced hyperphosphorylation of ZO-2. This corresponded with attenuation by staurosporine of 3-NC-induced increase in tight junction permeability, suggesting a relationship between ZO-2 phosphorylation and tight junction permeability.
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Affiliation(s)
- Peter D Ward
- Department of Pharmacology, School of Medicine, University of North Carolina, Chapel Hill, North Carolina 27599-7360, USA
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Ward PD, Haggart JW, Carter ES, Wilbur D, Tipper HW, Evans T. Sudden Productivity Collapse Associated with the Triassic-Jurassic Boundary Mass Extinction. Science 2001; 292:1148-51. [PMID: 11349146 DOI: 10.1126/science.1058574] [Citation(s) in RCA: 197] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The end-Triassic mass extinction is one of the five most catastrophic in Phanerozoic Earth history. Here we report carbon isotope evidence of a pronounced productivity collapse at the boundary, coincident with a sudden extinction among marine plankton, from stratigraphic sections on the Queen Charlotte Islands, British Columbia, Canada. This signal is similar to (though smaller than) the carbon isotope excursions associated with the Permian-Triassic and Cretaceous-Tertiary events.
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Affiliation(s)
- P D Ward
- Department of Earth and Space Sciences, University of Washington, Seattle, WA 98195, USA
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Abstract
The intestinal epithelium is a major barrier to the absorption of hydrophilic drugs. The presence of intercellular junctional complexes, particularly the tight junctions (zona occludens), renders the epithelium impervious to hydrophilic drugs, which cannot diffuse across the cells through the lipid bilayer of the cell membranes. There have been significant advances in understanding the structure and cellular regulation of tight junctions over the past decade. This article reviews current knowledge regarding the physiological regulation of tight junctions and paracellular permeability, and recent progress towards the rational design of agents that can effectively and safely increase paracellular permeability via modulation of tight junctions.
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Affiliation(s)
- PD Ward
- Department of Pharmacology, School of Medicine, University of North Carolina at Chapel Hill, 27599, Chapel Hill NC, USA
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Abstract
The Permian-Triassic transition in the Karoo Basin of South Africa was characterized by a rapid and apparently basin-wide change from meandering to braided river systems, as evidenced by preserved sedimentary facies. This radical changeover in river morphology is consistent with geomorphic consequences stemming from a rapid and major die-off of rooted plant life in the basin. Evidence from correlative nonmarine strata elsewhere in the world containing fluvial Permian-Triassic boundary sections suggests that a catastrophic terrestrial die-off of vegetation was a global event, producing a marked increase in sediment yield as well as contributing to the global delta(13)C excursion across the Permian-Triassic boundary.
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Affiliation(s)
- PD Ward
- Department of Geological Sciences, University of Washington, Seattle, WA 98195, USA. South African Museum, Cape Town, South Africa
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Ward PD, Hurtado JM, Kirschvink JL, Verosub KL. Measurements of the Cretaceous Paleolatitude of Vancouver Island: Consistent with the Baja-British Columbia Hypothesis. Science 1997. [DOI: 10.1126/science.277.5332.1642] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- Peter D. Ward
- P. D. Ward, Department of Geological Sciences, University of Washington, Seattle, WA 98195, USA
- J. M. Hurtado, Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- J. L. Kirschvink, Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA
- K. L. Verosub, Department of Geology, University of California, Davis, CA 95616, USA
| | - José M. Hurtado
- P. D. Ward, Department of Geological Sciences, University of Washington, Seattle, WA 98195, USA
- J. M. Hurtado, Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- J. L. Kirschvink, Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA
- K. L. Verosub, Department of Geology, University of California, Davis, CA 95616, USA
| | - Joseph L. Kirschvink
- P. D. Ward, Department of Geological Sciences, University of Washington, Seattle, WA 98195, USA
- J. M. Hurtado, Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- J. L. Kirschvink, Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA
- K. L. Verosub, Department of Geology, University of California, Davis, CA 95616, USA
| | - Kenneth L. Verosub
- P. D. Ward, Department of Geological Sciences, University of Washington, Seattle, WA 98195, USA
- J. M. Hurtado, Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- J. L. Kirschvink, Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA
- K. L. Verosub, Department of Geology, University of California, Davis, CA 95616, USA
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Abstract
Incompleteness of the fossil record has confounded attempts to establish the role of the end-Cretaceous bolide impact in the Late Cretaceous mass extinctions. Statistical analysis of latest Cretaceous outer-shelf macrofossils from western European Tethys reveals (i) a major extinction at or near the Cretaceous-Tertiary (K-T) boundary, probably caused by the impact, (ii) either a faunal abundance change or an extinction of up to nine ammonite species associated with a regression event shortly before the boundary, (iii) gradual extinction of most inoceramid bivalves well before the K-T boundary, and (iv) background extinction of approximately six ammonites throughout the latest Cretaceous.
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Affiliation(s)
- CR Marshall
- C. R. Marshall, Department of Earth and Space Sciences, Molecular Biology Institute, and Institute for Geophysics and Planetary Physics, University of California, Los Angeles, CA 90095-1567, USA. P. D. Ward, Department of Geological Sciences, AJ-20, University of Washington, Seattle, WA 98195, USA
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Nelson BK, Kenneth MacLeod G, Ward PD. Rapid change in strontium isotopic composition of sea water before the Cretaceous/Tertiary boundary. Nature 1991. [DOI: 10.1038/351644a0] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Morgan RA, Manning PB, Coran AG, Drongowski RA, Till GO, Ward PD, Oldham KT. Oxygen free radical activity during live E. coli septic shock in the dog. Circ Shock 1988; 25:319-23. [PMID: 3048773] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Free radicals generated during purine catabolism or by activated granulocytes cause tissue injury by peroxidation of lipid membranes. In a canine model of sepsis initiated by intravenous live Escherichia coli, fluorescent products of lipid peroxidation (FP) were measured in serum. Four groups of five dogs infused with 10(9)E. coli/kg were analyzed--I: no further treatment; II: prior depletion of granulocytes with a cytotoxic antibody; III: pre-treatment with superoxide dismutase and catalase; and IV: resuscitation after bacterial infusion to maintain cardiac output greater than 80% of pre-bacteremic levels. In Groups I, II, and III, cardiac output fell to less than 50% of baseline within 1 hr and remained there throughout the study. FP in Groups I and II rose to greater than 200% of baseline (P less than .02 and less than .03). In Groups III and IV, FP did not rise significantly from baseline. The rise in serum FP and the prevention of this rise by-treatment with antioxidants indicate generation of oxygen radicals. Their presence had no effect on hemodynamic parameters. Granulocyte depletion did not alter appearance of FP; however, prevention of low cardiac output blocked FP formation. These data suggest that oxygen free radicals were generated by tissue ischemia, rather than by granulocytes, in this model of septic shock.
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Affiliation(s)
- R A Morgan
- Shock Research Laboratory, Mott Children's Hospital, Ann Arbor, MI 48109
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Abstract
Commercial vaccines giving protection against three important bacterial fish diseases (enteric redmouth, furunculosis and vibriosis) became available in the United Kingdom in 1983. The degree of protection obtained and the cost effectiveness vary according to the method of presentation (injection, dipping or spraying and oral dosing). These methods and the optimum time for vaccination are described.
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de Swiet M, Ward PD, Fidler J, Horsman A, Katz D, Letsky E, Peacock M, Wise PH. Prolonged heparin therapy in pregnancy causes bone demineralization. Br J Obstet Gynaecol 1983; 90:1129-34. [PMID: 6652051 DOI: 10.1111/j.1471-0528.1983.tb06459.x] [Citation(s) in RCA: 106] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The relation of heparin therapy to osteoporosis was assessed in a retrospective analysis of 20 women treated during and after pregnancy with subcutaneous heparin for thromboembolism prophylaxis. The phalangeal cortical area ratio was significantly less after long term therapy (greater than 25 weeks) compared with that after short term therapy (less than 7 weeks). The same trend was found in the metacarpal area ratio, although this did not reach statistical significance. The changes were most marked in a woman who had received heparin also in a previous pregnancy. No correlations were found between duration of therapy and back pain, conventional radiology of lumbar spine or the Singh index of femoral trabecular pattern which were within the normal range in all patients. The findings indicate a dose-related demineralization process associated with prophylactic heparin therapy in pregnancy. The correct methods of and criteria for thromboembolism prophylaxis in pregnancy need critical re-examination.
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Ward PD, Carter G, MacGregor G. Overdose of trilostane. Br Med J (Clin Res Ed) 1983; 287:216. [PMID: 6409260 PMCID: PMC1548644 DOI: 10.1136/bmj.287.6386.216-a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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Ward PD. Invertebrate Paleobiology. Science 1982; 216:726. [PMID: 17730133 DOI: 10.1126/science.216.4547.726] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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Ward PD. Invertebrate Paleobiology:
The Ammonites
. Their Life and Their World. Ulrich Lehmann. Translated from the German edition (Stuttgart, 1976) by Janine Lettau. Cambridge University Press, New York, 1981. xiv, 246 pp., illus. $19.95. Science 1982. [DOI: 10.1126/science.216.4547.726.a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- Peter D. Ward
- Department of Geology, University of California, Davis 95616
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Adlam C, Kerry JB, Edkins S, Ward PD. Local and systemic antibody responses in cows following immunization with staphylococcal antigens in the dry period. J Comp Pathol 1981; 91:105-13. [PMID: 7343566 DOI: 10.1016/0021-9975(81)90050-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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Fowler PB, Alaghband-Zadeh J, Ward PD. Premyxoedema in Busselton. Lancet 1980; 2:1250. [PMID: 6108423 DOI: 10.1016/s0140-6736(80)92512-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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Abstract
The Panton-Valentine leukocidin of Staphylococcus aureus was shown to exhibit a potent dermonecrotic effect when injected intradermally into rabbits. This effect could be abrogated by immunizing animals with the F component or both components, but immunization with the S component appeared to exacerbate certain of the intradermal responses.
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Adlam C, Ward PD, Turner WH. Effect of immunization with highly purified Panton-Valentine leucocidin and delta-toxin on staphylococcal mastitis in rabbits. J Comp Pathol 1980; 90:265-74. [PMID: 7191862 DOI: 10.1016/0021-9975(80)90063-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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Ward PD, Adlam C, McCartney AC, Arbuthnott JP, Thorley CM. A histopathological study of the effects of highly purified staphlococcal alpha and beta toxins on the lactating mammary gland and skin of the rabbit. J Comp Pathol 1979; 89:169-77. [PMID: 572377 DOI: 10.1016/0021-9975(79)90056-2] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Ward PD. CHA president cites objections to provisions of health planning law. Rev Fed Am Hosp 1978; 11:24-6. [PMID: 10238718] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
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Adlam C, Ward PD, McCartney AC, Arbuthnott JP, Thorley CM. Effect immunization with highly purified alpha- and beta-toxins on staphylococcal mastitis in rabbits. Infect Immun 1977; 17:250-6. [PMID: 561034 PMCID: PMC421109 DOI: 10.1128/iai.17.2.250-256.1977] [Citation(s) in RCA: 59] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Experiments were carried out to determine whether immunization of female rabbits with highly purified staphylococcal alpha- or beta-toxins would protect them against intramammary challenge with staphylococci. High circulating anti-alpha-toxin titers reduced the lethal hemorrhagic edematous form of the disease ("blue-breast") produced by strains BB and Compton 201 to a localized chronic abscess form. No such protection was afforded by high anti-beta-toxin titers. Immunization with alpha- or beta-toxins produced no change in the clinical picture of the disease produced by CN.6708, a strain of Staphylococcus responsible for a natural outbreak of abscess-type rabbit mastitis. From these experiments it would appear that alpha-toxin is a key antigen in the blue-breast form of rabbit mastitis. Since the abscess form of the disease was not prevented by immunization with either alpha- or beta-toxin, other virulence factors must be acting to produce this more localized disease.
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