220 results on '"Armstrong, Richard"'
Search Results
2. THE FOB.
- Author
-
Chenevey, Jerry, Lange, Dave, Steinhoff, Gordon, Maresca, Greg, and Armstrong, Richard
- Subjects
MASTER'S degree ,NATIONAL security - Abstract
The given text is an article from the American Legion magazine. It includes various sections discussing different topics. The first section pays tribute to Carl Erskine, a World War II veteran and former baseball player, who passed away. The second section discusses the Vietnam War and the author's perspective on the sacrifices made during that time. The third section highlights the accomplishments and contributions of Whitey Herzog, a former baseball manager. The fourth section mentions the Whitey Herzog Youth Foundation and its support for youth baseball programs. The fifth section features letters from readers expressing their opinions on different topics, including national security, foreign aid, and tax refunds. [Extracted from the article]
- Published
- 2024
3. Germline PTPN13mutations in patients with bone marrow failure and acute lymphoblastic leukemia
- Author
-
Moshiri, Houtan, Cabrera Riofrío, David A., Lim, Yeon Jung, Lauhasurayotin, Supanun, Manisterski, Michal, Elhasid, Ronit, Bonilla, Francisco A., Dhanraj, Santhosh, Armstrong, Richard N., Li, Hongbing, Scherer, Stephen W., Hernández-Hernández, Angel, and Dror, Yigal
- Published
- 2022
- Full Text
- View/download PDF
4. Tear Film Surface Quality in Modern Daily Disposable Contact Lens Wear
- Author
-
Mousavi, Maryam, Garaszczuk, Izabela K., De Jesus, Danilo Andrade, Szczesna-Iskander, Dorota H., Armstrong, Richard A., Nichols, Kelly K., and Iskander, D. Robert
- Published
- 2021
- Full Text
- View/download PDF
5. The Effect of Mode of Anaesthesia on Outcomes After Elective Endovascular Repair of Abdominal Aortic Aneurysm.
- Author
-
Dovell, George, Rogers, Chris A., Armstrong, Richard, Harris, Rosie A., Hinchliffe, Robert J., and Mouton, Ronelle
- Abstract
Endovascular aneurysm repair (EVAR) is the most commonly used method to repair abdominal aortic aneurysms. EVAR can be performed using a variety of anaesthetic techniques, including general anaesthetic (GA), regional anaesthetic (RA), and local anaesthetic (LA), but little is known about the effects that each of these anaesthetic modes have on patient outcome. The aim of this study was to assess the effect of anaesthetic technique on early outcomes after elective EVAR. Data from the UK's National Vascular Registry were analysed. All patients undergoing elective standard infrarenal EVAR between 1 January 2014 and 31 December 2016 were included. Patients with a symptomatic aneurysm treated semi-electively were excluded. The primary outcome was in hospital death within 30 days of surgery. Secondary outcomes included post-operative complications and length of hospital stay. Time to event outcomes were compared using Cox proportional hazards regression adjusted for confounders, including British Aneurysm Repair score (a validated aneurysm risk prediction score that is calculated using age, sex, creatinine, cardiac disease, electrocardiogram, previous aortic surgery, white blood cell count, serum sodium, abdominal aortic aneurysm diameter, and American Society of Anaesthesiologists grade) and chronic lung disease. A total of 9783 patients received an elective, standard infrarenal EVAR (GA, n = 7069; RA, n = 2347; and LA, n = 367) across 89 hospitals. RA and/or LA was used in 82 hospitals. There were 64 in hospital deaths within 30 days, 50 (0.9% mortality at 30 days, 95% confidence interval [CI] 0.7–1.2) in the GA group, 11 (0.6%, 95% CI 0.3–1.1) in the RA group, and three (1.5%, 95% CI 0.5–4.7) in the LA group. The mortality rate differed between groups (p =.03) and was significantly lower in the RA group compared with the GA group (adjusted hazard ratio [aHR] RA/GA 0.37 [95% CI 0.17–0.81]; LA/GA 0.63 [95% CI 0.15–2.69]). The median length of stay was two days for all modes of anaesthesia, but patients were discharged from hospital more quickly in the RA and LA groups than the GA group (aHR RA/GA 1.10 [95% CI 1.03–1.17]; LA/GA 1.15 [95% CI 1.02–1.29]). Overall, 20.7% of patients experienced one or more complications (GA group, 22.1%; RA group, 16.8%; LA group, 17.7%) and pulmonary complications occurred with similar frequency in the three groups (overall 2.4%, adjusted odds ratio RA/GA 0.93 [95% CI 0.66–1.32]; LA/GA 0.82 [95% CI 0.41–1.63]). Thirty day mortality was lower with RA than with GA, but mode of anaesthesia was not associated with increased complications for patients undergoing elective standard infrarenal EVAR. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
6. A Vision Splendid: The Discourses of David O. McKay.
- Author
-
Armstrong, Richard N.
- Abstract
As you read McKay's nonconference addresses, your appreciation for the depth and breadth of David O. McKay's intellect and oratory will be significantly enhanced. What makes this book so interesting is that Lampropoulos has mined her great-aunt's scrapbooks for transcripts of McKay's speaking - not at general conference - but for dedications, civic addresses, funeral sermons, and other church addresses. I highly recommend Anne-Marie Wright Lampropoulos's I A Vision Splendid: The Discourses of David O. McKay i . [Extracted from the article]
- Published
- 2023
- Full Text
- View/download PDF
7. Efficiency of ground motion intensity measures with earthquake-induced earth dam deformations
- Author
-
Armstrong, Richard, Kishida, Tadahiro, and Park, DongSoon
- Abstract
In a seismic hazard analysis (SHA), the earthquake loading level should be predicted for one or more ground motion intensity measures (IMs) that are expected to relate well with the engineering demand parameters (EDPs) of the site. In this study, the goal was to determine the IMs that best relate to embankment dam deformations based on nonlinear deformation analysis (NDA) results of two embankment dams with a large suite of recorded ground motions. The measure utilized to determine the “best” IM was standard deviation in the engineering demand parameter (e.g., deformation) for a given IM, also termed “efficiency.” Results of the study demonstrated that for the NDA model used, Arias intensity (AI) was found to be the most efficient predictor of embankment dam deformations. In terms of pseudo-spectral acceleration (PSA)-based IMs, the PSA at short periods and then in the general range of the natural period of the dams was seen to be the most efficient IM, but was in almost all cases not as efficient as AI.
- Published
- 2021
- Full Text
- View/download PDF
8. Modulus reductions of dam embankment materials based on downhole array time series
- Author
-
Kishida, Tadahiro, Park, DongSoon, Sousa, Rita L., Armstrong, Richard, and Byon, Young-Ji
- Abstract
A database of three-component acceleration time series recorded at downhole arrays in earthen dam cores was published by the Japan Commission on Large Dams. This study reviews the acceleration time series in nine earthfill and rockfill dams in Japan. The apparent shear wave velocities between downhole sensors in each dam during strong shakes are determined by calculating the wave travel time between the recorded time series. Transient shear strains are calculated from the differences in the displacement time series between sensors through the double integration of filtered acceleration time series. The modulus reduction curves of the in situ core materials are constructed by combining the apparent shear wave velocities and shear strains. The modulus reduction data are then compared with empirical models. Observations show considerable uncertainties and dam-dependent characteristics in the extracted in situ shear modulus. Accordingly, this study proposes a methodology to update the empirical modulus reduction model for dam core materials on the basis of observed data on downhole time series.
- Published
- 2020
- Full Text
- View/download PDF
9. Stenian A-type granitoids in the Namaqua-Natal Belt, southern Africa, Maud Belt, Antarctica and Nampula Terrane, Mozambique: Rodinia and Gondwana amalgamation implications.
- Author
-
Hokada, Tomokazu, Grantham, Geoffrey H., Arima, Makoto, Saito, Satoshi, Shiraishi, Kazuyuki, Armstrong, Richard A., Eglington, Bruce, Misawa, Keiji, and Kaiden, Hiroshi
- Abstract
We carried out SHRIMP zircon U-Pb dating on A-type granitic intrusions from the Namaqua-Natal Province, South Africa, Sverdrupfjella, western Dronning Maud Land, Antarctica and the Nampula Province of northern Mozambique. Zircon grains in these granitic rocks are typically elongated and oscillatory zoned, suggesting magmatic origins. Zircons from the granitoid intrusions analyzed in this study suggest ∼1025–1100 Ma ages, which confirm widespread Mesoproterozoic A-type granitic magmatism in the Namaqua-Natal (South Africa), Maud (Antarctica) and Mozambique metamorphic terrains. No older inherited (e.g., ∼2500 Ma Achean basement or ∼1200 Ma island arc magmatism in northern Natal) zircon grains were seen. Four plutons from the Natal Belt (Mvoti Pluton, Glendale Pluton, Kwalembe Pluton, Ntimbankulu Pluton) display 1050–1040 Ma ages, whereas the Nthlimbitwa Pluton in northern Natal indicates older 1090–1080 Ma ages. A sample from Sverdrupfjella, Antarctica has ∼1091 Ma old zircons along with ∼530 Ma metamorphic rims. Similarly, four samples analysed from the Nampula Province of Mozambique suggest crystallization ages of ∼1060–1090 Ma but also show significant discordance with two samples showing younger ∼550 Ma overgrowths. None of the Natal samples show any younger overgrowths. A single sample from southwestern Namaqualand yielded an age of ∼1033 Ma. Currently available chronological data suggest magmatism took place in the Namaqua-Natal-Maud-Mozambique (NNMM) belt between ∼1025 Ma and ∼1100 Ma with two broad phases between ∼1060–1020 Ma and 1100–1070 Ma respectively, with peaks at between ∼1030–1040 Ma and ∼1070–1090 Ma. The age data from the granitic intrusions from Namaqualand, combined with those from Natal, Antarctica and Mozambique suggest a crude spatial-age relationship with the older >1070 Ma ages being largely restricted close to the eastern and western margins of the Kalahari Craton in northern Natal, Mozambique, Namaqualand and WDML Antarctica whereas the younger <1060 Ma ages dominate in southern Natal and western Namaqualand and are largely restricted to the southern and possibly the western margins of the Kalahari Craton. The older ages of magmatism partially overlap with or are marginally younger than the intracratonic Mkondo Large Igneous Province intruded into or extruded onto the Kalahari Craton, suggesting a tectonic relationship with the Maud Belt. Similar ages from granitic augen gneisses in Sri Lanka suggest a continuous belt stretching from Namaqualand to Sri Lanka in a reconstituted Gondwana, formed during the terminal stages of amalgamation of Rodinia and predating the East African Orogen. This contiguity contributes to defining the extent of Rodinia-age crustal blocks, subsequently fragmented by the dispersal of Rodinia and Gondwana. Image 1 • 12 Mesoproterozoic U/Pb zircon ages from A-type granites from the Namaqua-Natal-Maud-Nampula Mozambique Belts are described. • The new data, along with data from other publications, confirm two age groups in the Belts. • The contiguity of data supports the grouping of continental fragments at ∼1000-1100Ma and possibly extends it to Sri Lanka. • The overlapping timing of magmatism with the intracratonic Mkondo LIP suggests a causal plate tectonic relationship. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
10. News from ESC 2019.
- Author
-
Armstrong, Richard and Puttana, Amar
- Published
- 2019
11. Type of Anesthesia for Endovascular Abdominal Aortic Aneurysm Repair.
- Author
-
Armstrong, Richard A., Squire, Yolande G., Rogers, Chris A., Hinchliffe, Robert J., and Mouton, Ronelle
- Abstract
Objective Endovascular aneurysm repair (EVAR) is used increasingly in the management of patients with abdominal aortic aneurysms (AAAs), including in the emergency setting for ruptured AAA. The lower mortality among patients undergoing emergency EVAR under local anesthesia (LA) observed in the Immediate Management of Patients with Rupture: Open Versus Endovascular Repair trial has sparked renewed interest in the anesthesia choice for EVAR. This systematic review evaluates the effect of mode of anesthesia on outcomes after EVAR. Design The review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. The primary outcome was in-hospital/30-day mortality, and both emergency and elective EVAR were included. The relative risk of death was estimated for each individual study without adjustment for potential confounding factors. Setting Hospitals. Participants A total of 39,744 patients from 22 nonrandomized studies were included in the analysis. Interventions None. Measurements and Main Results Sixteen studies in 23,202 patients compared LA to general anesthesia (GA) and reported in-hospital/30-day mortality. The unadjusted risk of death after emergency EVAR with LA was lower than with GA. Trends in elective surgery were less clear. Conclusion There is some evidence across both emergency and elective settings to suggest that mode of anesthesia may be associated with improved outcomes. In particular, LA appears to have a positive effect on outcome after emergency EVAR. Because of the lack of randomized trial data, a significant risk of confounding remains. The optimal mode of anesthesia for EVAR should be investigated further and the reasons why particular anesthesia techniques are chosen for particular patients identified. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
12. THE GENERAL CONFERENCE RHETORIC OF WILFORD WOODRUFF.
- Author
-
Armstrong, Richard N.
- Abstract
The article presents a review of conference addresses by Wilford Woodruff, president of the Church of Jesus Christ of Latter-day Saints (LDS Church) from 1889 until his death in 1898. His speeches focused on revelation, plural marriage and temple work and their contributions to the development of Mormonism. His public speaking style had been recognized despite the fact that he had no formal oratorical training. He regarded the LDS Church as the literal Kingdom of God prophesied by Daniel.
- Published
- 2019
- Full Text
- View/download PDF
13. Percutaneous endovascular repair of congenital interruption of the thoracic aorta.
- Author
-
Armstrong, Richard, Mulcahy, David, and Walsh, Kevin
- Published
- 2018
14. Response of high-risk MDS to azacitidine and lenalidomide is impacted by baseline and acquired mutations in a cluster of three inositide-specific genes
- Author
-
Follo, Matilde Y., Pellagatti, Andrea, Armstrong, Richard N., Ratti, Stefano, Mongiorgi, Sara, De Fanti, Sara, Bochicchio, Maria Teresa, Russo, Domenico, Gobbi, Marco, Miglino, Maurizio, Parisi, Sarah, Martinelli, Giovanni, Cavo, Michele, Luiselli, Donata, McCubrey, James A., Suh, Pann-Ghill, Manzoli, Lucia, Boultwood, Jacqueline, Finelli, Carlo, and Cocco, Lucio
- Abstract
Specific myeloid-related and inositide-specific gene mutations can be linked to myelodysplastic syndromes (MDS) pathogenesis and therapy. Here, 44 higher-risk MDS patients were treated with azacitidine and lenalidomide and mutations analyses were performed at baseline and during the therapy. Results were then correlated to clinical outcome, overall survival (OS), leukemia-free-survival (LFS) and response to therapy. Collectively, 34/44 patients were considered evaluable for response, with an overall response rate of 76.25% (26/34 cases): 17 patients showed a durable response, 9 patients early lost response and 8 patients never responded. The most frequently mutated genes were ASXL1, TET2, RUNX1, and SRSF2. All patients early losing response, as well as cases never responding, acquired the same 3 point mutations during therapy, affecting respectively PIK3CD (D133E), AKT3 (D280G), and PLCG2 (Q548R) genes, that regulate cell proliferation and differentiation. Moreover, Kaplan–Meier analyses revealed that this mutated cluster was significantly associated with a shorter OS, LFS, and duration of response. All in all, a common mutated cluster affecting 3 inositide-specific genes is significantly associated with loss of response to azacitidine and lenalidomide therapy in higher risk MDS. Further studies are warranted to confirm these data and to further analyze the functional role of this 3-gene cluster.
- Published
- 2019
- Full Text
- View/download PDF
15. Orthopaedic registries – the UK view (National Joint Registry): impact on practice
- Author
-
Porter, Martyn, Armstrong, Richard, Howard, Peter, Porteous, Matthew, and Wilkinson, J. Mark
- Abstract
The National Joint Registry (NJR) was established in 2002 as the result of an unexpectedly high failure rate of a cemented total hip replacement.Initial compliance with the Registry was low until data entry was mandated. Current case ascertainment is approximately 95% for primary procedures and 90% for revision procedures.The NJR links to other data sources to enrich the reporting processes. The NJR provides several web-based and open-access reports to the public and detailed confidential performance reports to individual surgeons, hospitals and industry bodies.A transparency and accountability process ensures that device and surgical performance are actively monitored on a six-monthly basis, and adverse variation is dealt with in an appropriate way that underpins patient safety.The NJR also manages a comprehensive research-ready database and data protection compliant access system that enables external researchers to use the dataset and perform independent analyses for patient benefit.Moving forwards, the NJR intends to look at factors that lead to better outcomes so that good practice can be embedded into routine care.Cite this article: EFORT Open Rev2019;4 DOI: 10.1302/2058-5241.4.180084
- Published
- 2019
- Full Text
- View/download PDF
16. The incidence of cardiac arrest in the intensive care unit: A systematic review and meta-analysis
- Author
-
Armstrong, Richard A, Kane, Caroline, Oglesby, Fiona, Barnard, Katie, Soar, Jasmeet, and Thomas, Matt
- Abstract
The incidence of cardiac arrest in the intensive care unit (ICU-CA) has not been widely reported. We undertook a systematic review and meta-analysis of studies reporting the incidence of cardiac arrest in adult, general intensive care units. The review was prospectively registered with PROSPERO (CRD42017079717). The search identified 7550 records, which included 20 relevant studies for qualitative analysis and 16 of these were included for quantitative analyses. The reported incidence of ICU-CA was 22.7 per 1000 admissions (95% CI: 17.4–29.6) with survival to hospital discharge of 17% (95% CI: 9.5–28.5%). We estimate that at least 5446 patients in the UK have a cardiac arrest after ICU admission. There are limited data and significant variation in the incidence of ICU-CA and efforts to synthesise these are limited by inconsistent reporting. Further prospective studies with standardised process and incidence measures are required to define this important patient group.
- Published
- 2019
- Full Text
- View/download PDF
17. Who's been using my burial mound? Radiocarbon dating and isotopic tracing of human diet and mobility at the collective burial site, Le Tumulus des Sables, southwest France
- Author
-
James, Hannah F., Willmes, Malte, Boel, Ceridwen A., Courtaud, Patrice, Chancerel, Antoine, Ciesielski, Elsa, Desideri, Jocelyne, Bridy, Audrey, Wood, Rachel, Moffat, Ian, Fallon, Stewart, McMorrow, Linda, Armstrong, Richard A., Williams, Ian S., Kinsley, Leslie, Aubert, Maxime, Eggins, Stephen, Frieman, Catherine J., and Grün, Rainer
- Abstract
The burial mound of Le Tumulus des Sables, southwest France, contains archaeological artefacts spanning from the Neolithic to the Iron Age. Human remains have been found throughout the burial mound, however their highly fragmented state complicates the association between the burial mound structure and the archaeological material. Radiocarbon dating and isotopic analyses of human teeth have been used to investigate the chronology, diet and mobility of the occupants. Radiocarbon dating shows that the site was used for burials from the Neolithic to Iron Age, consistent with the range of archaeological artefacts recovered. δ13C and δ15N values (from dentine collagen) suggest a predominately terrestrial diet for the population, unchanging through time. 87Sr/86Sr (on enamel and dentine) and δ18O (on enamel) values are consistent with occupation of the surrounding region, with one individual having a δ18O value consistent with a childhood spent elsewhere, in a colder climate region. These results showcase the complex reuse of this burial mound by a mostly local population over a period of about 2000 years.
- Published
- 2019
- Full Text
- View/download PDF
18. Cellular and Molecular Analysis of Hematopoietic Stem and Progenitor Cells in Shwachman-Diamond Syndrome
- Author
-
Photia, Apichat, Benicio, Mariana, Sahinoglu, Efe, Li, Hongbing, Armstrong, Richard Neil, Moshiri, Houtan, Klaassen, Robert J., Pastore, Yves D, Dick, John E., and Dror, Yigal
- Abstract
Shwachman-Diamond syndrome (SDS)is an inherited multi-organ disorder with bone marrow failure (BMF), which may include neutropenia, anemia, and thrombocytopenia, as well as a high risk of myelodysplasia and leukemia. Hematological complications are common causes of morbidity and mortality in SDS. Around 90% of SDS patients have biallelic mutations in the Shwachman-Bodian-Diamond Syndrome( SBDS) gene, which plays an important role in ribosome biogenesis and hematopoietic cell survival. In a collaborative study led by Dr. John Dick (Science 2016) novel hematopoietic progenitor subsets were identified (noted as F1, F2 and F3), of which the abundance, clonal capacity, and function in disease states remain unknown. We hypothesized that cellular and molecular analysis of hematopoietic stem and progenitor cells (HSPC) including these novel progenitors would provide valuable insights into the pathogenesis of BMF in SDS.
- Published
- 2023
- Full Text
- View/download PDF
19. Postoperative Cognitive Dysfunction.
- Author
-
Page, Valerie, Oglesby, Fiona, and Armstrong, Richard
- Published
- 2017
- Full Text
- View/download PDF
20. Hot lherzolite exhumation, UHT migmatite formation, and acid volcanism driven by Miocene rollback of the Banda Arc, eastern Indonesia.
- Author
-
Pownall, Jonathan M., Hall, Robert, and Armstrong, Richard A.
- Abstract
The northern Banda Arc, eastern Indonesia, exposes upper mantle/lower crustal complexes comprising lherzolites and granulite facies migmatites of the ‘Kobipoto Complex’. Residual garnet–sillimanite granulites, which contain spinel + quartz inclusions within garnet, experienced ultrahigh-temperature (UHT; > 900 °C) conditions at 16 Ma due to heat supplied by lherzolites exhumed during slab rollback in the Banda Arc. Here, we present U–Pb zircon ages and new whole-rock geochemical analyses that document a protracted history of high -T metamorphism, melting, and acid magmatism of a common sedimentary protolith. Detrital zircons from the Kobipoto Complex migmatites, with ages between 3.4 Ga and 216 Ma, show that their protolith was derived from both West Papua and the Archean of Western Australia, and that metamorphism of these rocks on Seram could not have occurred until the Late Triassic. Zircons within the granulites then experienced three subsequent episodes of growth – at 215–173 Ma, 25–20 Ma, and at c . 16 Ma. The population of zircon rims with ages between 215 and 173 Ma document significant metamorphic (± partial melting) events that we attribute to subduction beneath the Bird's Head peninsula and Sula Spur, which occurred until the Banda and Argo continental blocks were rifted from the NW Australian margin of Gondwana in the Late Jurassic (from c . 160 Ma). Late Oligocene-Early Miocene collision between Australia (the Sula Spur) and SE Asia (northern Sulawesi) was then recorded by crystallisation of several 25–20 Ma zircon rims. Thereafter, a large population of c . 16 Ma zircon rims grew during subsequent and extensive Middle Miocene metamorphism and melting of the Kobipoto complex rocks beneath Seram under high- to ultrahigh-temperature (HT–UHT) conditions. Lherzolites located adjacent to the granulite-facies migmatites in central Seram equilibrated at 1280–1300 °C upon their exhumation to 1 GPa (~ 37 km) depth, whereupon they supplied sufficient heat to have metamorphosed adjacent Kobipoto Complex migmatites under UHT conditions at 16 Ma. Calculations suggesting slight (~ 10 vol%) mantle melting are consistent with observations of minor gabbroic intrusions and scarce harzburgites. Subsequent extension during continued slab rollback exhumed both the lherzolites and adjacent granulite-facies migmatites beneath extensional detachment faults in western Seram at 6.0–5.5 Ma, and on Ambon at 3.5 Ma, as recorded by subsequent zircon growth and 40 Ar/ 39 Ar ages in these regions. Ambonites, cordierite- and garnet-bearing dacites sourced predominantly from melts generated in the Kobipoto Complex migmatites, were later erupted on Ambon from 3.0 to 1.9 Ma. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
21. Structural Dynamics of 15-Lipoxygenase-2 via Hydrogen-Deuterium Exchange.
- Author
-
Droege, Kristin D., Keithly, Mary E., Sanders, Charles R., Armstrong, Richard N., and Thompson, Matthew K.
- Published
- 2017
- Full Text
- View/download PDF
22. Global Kinetic Mechanism of Microsomal Glutathione Transferase 1 and Insights into Dynamic Enzyme Activation.
- Author
-
Spahiu, Linda, Ålander, Johan, Ottosson-Wadlund, Astrid, Svensson, Richard, Lehmer, Carina, Armstrong, Richard N., and Morgenstern, Ralf
- Published
- 2017
- Full Text
- View/download PDF
23. Impact of spliceosome mutations on RNA splicing in myelodysplasia: dysregulated genes/pathways and clinical associations
- Author
-
Pellagatti, Andrea, Armstrong, Richard N., Steeples, Violetta, Sharma, Eshita, Repapi, Emmanouela, Singh, Shalini, Sanchi, Andrea, Radujkovic, Aleksandar, Horn, Patrick, Dolatshad, Hamid, Roy, Swagata, Broxholme, John, Lockstone, Helen, Taylor, Stephen, Giagounidis, Aristoteles, Vyas, Paresh, Schuh, Anna, Hamblin, Angela, Papaemmanuil, Elli, Killick, Sally, Malcovati, Luca, Hennrich, Marco L., Gavin, Anne-Claude, Ho, Anthony D., Luft, Thomas, Hellström-Lindberg, Eva, Cazzola, Mario, Smith, Christopher W. J., Smith, Stephen, and Boultwood, Jacqueline
- Abstract
SF3B1, SRSF2, and U2AF1 are the most frequently mutated splicing factor genes in the myelodysplastic syndromes (MDS). We have performed a comprehensive and systematic analysis to determine the effect of these commonly mutated splicing factors on pre-mRNA splicing in the bone marrow stem/progenitor cells and in the erythroid and myeloid precursors in splicing factor mutant MDS. Using RNA-seq, we determined the aberrantly spliced genes and dysregulated pathways in CD34+ cells of 84 patients with MDS. Splicing factor mutations result in different alterations in splicing and largely affect different genes, but these converge in common dysregulated pathways and cellular processes, focused on RNA splicing, protein synthesis, and mitochondrial dysfunction, suggesting common mechanisms of action in MDS. Many of these dysregulated pathways and cellular processes can be linked to the known disease pathophysiology associated with splicing factor mutations in MDS, whereas several others have not been previously associated with MDS, such as sirtuin signaling. We identified aberrantly spliced events associated with clinical variables, and isoforms that independently predict survival in MDS and implicate dysregulation of focal adhesion and extracellular exosomes as drivers of poor survival. Aberrantly spliced genes and dysregulated pathways were identified in the MDS-affected lineages in splicing factor mutant MDS. Functional studies demonstrated that knockdown of the mitosis regulators SEPT2 and AKAP8, aberrantly spliced target genes of SF3B1 and SRSF2 mutations, respectively, led to impaired erythroid cell growth and differentiation. This study illuminates the effect of the common spliceosome mutations on the MDS phenotype and provides novel insights into disease pathophysiology.
- Published
- 2018
- Full Text
- View/download PDF
24. Impact of spliceosome mutations on RNA splicing in myelodysplasia: dysregulated genes/pathways and clinical associations
- Author
-
Pellagatti, Andrea, Armstrong, Richard N., Steeples, Violetta, Sharma, Eshita, Repapi, Emmanouela, Singh, Shalini, Sanchi, Andrea, Radujkovic, Aleksandar, Horn, Patrick, Dolatshad, Hamid, Roy, Swagata, Broxholme, John, Lockstone, Helen, Taylor, Stephen, Giagounidis, Aristoteles, Vyas, Paresh, Schuh, Anna, Hamblin, Angela, Papaemmanuil, Elli, Killick, Sally, Malcovati, Luca, Hennrich, Marco L., Gavin, Anne-Claude, Ho, Anthony D., Luft, Thomas, Hellström-Lindberg, Eva, Cazzola, Mario, Smith, Christopher W.J., Smith, Stephen, and Boultwood, Jacqueline
- Abstract
SF3B1, SRSF2, and U2AF1are the most frequently mutated splicing factor genes in the myelodysplastic syndromes (MDS). We have performed a comprehensive and systematic analysis to determine the effect of these commonly mutated splicing factors on pre-mRNA splicing in the bone marrow stem/progenitor cells and in the erythroid and myeloid precursors in splicing factor mutant MDS. Using RNA-seq, we determined the aberrantly spliced genes and dysregulated pathways in CD34+cells of 84 patients with MDS. Splicing factor mutations result in different alterations in splicing and largely affect different genes, but these converge in common dysregulated pathways and cellular processes, focused on RNA splicing, protein synthesis, and mitochondrial dysfunction, suggesting common mechanisms of action in MDS. Many of these dysregulated pathways and cellular processes can be linked to the known disease pathophysiology associated with splicing factor mutations in MDS, whereas several others have not been previously associated with MDS, such as sirtuin signaling. We identified aberrantly spliced events associated with clinical variables, and isoforms that independently predict survival in MDS and implicate dysregulation of focal adhesion and extracellular exosomes as drivers of poor survival. Aberrantly spliced genes and dysregulated pathways were identified in the MDS-affected lineages in splicing factor mutant MDS. Functional studies demonstrated that knockdown of the mitosis regulators SEPT2and AKAP8,aberrantly spliced target genes of SF3B1and SRSF2mutations, respectively, led to impaired erythroid cell growth and differentiation. This study illuminates the effect of the common spliceosome mutations on the MDS phenotype and provides novel insights into disease pathophysiology.
- Published
- 2018
- Full Text
- View/download PDF
25. Variations in Patterns of Utilization and Charges for the Care of Low Back Pain in North Carolina, 2000 to 2009: A Statewide Claims’ Data Analysis.
- Author
-
Hurwitz, Eric L., Li, Dongmei, Guillen, Jenni, Schneider, Michael J., Stevans, Joel M., Phillips, Reed B., Phelan, Shawn P., Lewis, Eugene A., Armstrong, Richard C., and Vassilaki, Maria
- Abstract
Objectives The purpose of the study was to compare utilization and charges generated by medical doctors (MD), doctors of chiropractic (DC) and physical therapists (PT) by patterns of care for the treatment of low back pain in North Carolina. Methods This was an analysis of low-back-pain-related closed claim data from the North Carolina State Health Plan for Teachers and State Employees from 2000 to 2009. Data were extracted from Blue Cross Blue Shield of North Carolina for the North Carolina State Health Plan using International Classification of Diseases, 9th Revision diagnostic codes for uncomplicated low back pain (ULBP) and complicated low back pain (CLBP). Results Care patterns with single-provider types and no referrals incurred the least charges on average for both ULBP and CLBP. When care did not include referral providers or services, for ULBP, MD and DC care was on average $465 less than MD and PT care. For CLBP, MD and DC care averaged $965 more than MD and PT care. However, when care involved referral providers or services, MD and DC care was on average $1600 less when compared to MD and PT care for ULBP and $1885 less for CLBP. Risk-adjusted charges (available 2006-2009) for patients in the middle quintile of risk were significantly less for DC care patterns. Conclusions Chiropractic care alone or DC with MD care incurred appreciably fewer charges for ULBP than MD care with or without PT care. This finding was reversed for CLBP. Adjusted charges for both ULBP and CLBP patients were significantly lower for DC patients. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
26. Variations in Patterns of Utilization and Charges for the Care of Headache in North Carolina, 2000-2009: A Statewide Claims’ Data Analysis.
- Author
-
Hurwitz, Eric L., Vassilaki, Maria, Li, Dongmei, Schneider, Michael J., Stevans, Joel M., Phillips, Reed B., Phelan, Shawn P., Lewis, Eugene A., and Armstrong, Richard C.
- Abstract
Objectives The purpose of the study was to compare patterns of utilization and charges generated by medical doctors (MDs), doctors of chiropractic (DCs), and physical therapists (PTs) for the treatment of headache in North Carolina. Methods Retrospective analysis of claims data from the North Carolina State Health Plan for Teachers and State Employees from 2000 to 2009. Data were extracted from Blue Cross Blue Shield of North Carolina for the North Carolina State Health Plan using International Classification of Diseases, Ninth Revision, diagnostic codes for headache. The claims were separated by individual provider type, combination of provider types, and referral patterns. Results The majority of patients and claims were in the MD-only or MD plus referral patterns. Chiropractic patterns represented less than 10% of patients. Care patterns with single-provider types and no referrals incurred the least charges on average for headache. When care did not include referral providers or services, MD with DC care was generally less expensive than MD care with PT. However, when combined with referral care, MD care with PT was generally less expensive. Compared with MD-only care, risk-adjusted charges (available 2006-2009) for patients in the middle risk quintile were significantly less for DC-only care. Conclusions Utilization and expenditures for headache treatment increased from 2000 to 2009 across all provider groups. MD care represented the majority of total allowed charges in this study. MD care and DC care, alone or in combination, were overall the least expensive patterns of headache care. Risk-adjusted charges were significantly less for DC-only care. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
27. Variations in Patterns of Utilization and Charges for the Care of Neck Pain in North Carolina, 2000 to 2009: A Statewide Claims’ Data Analysis.
- Author
-
Hurwitz, Eric L., Li, Dongmei, Guillen, Jenni, Schneider, Michael J., Stevans, Joel M., Phillips, Reed B., Phelan, Shawn P., Lewis, Eugene A., Armstrong, Richard C., and Vassilaki, Maria
- Abstract
Objectives The purpose of the study was to compare utilization and charges generated by medical doctors (MD), doctors of chiropractic (DC) and physical therapists (PT) by provider patterns of care for the treatment of neck pain in North Carolina. Methods This was an analysis of neck-pain-related closed claim data from the North Carolina State Health Plan for Teachers and State Employees (NCSHP) from 2000 to 2009. Data were extracted from Blue Cross Blue Shield of North Carolina for the NCSHP using ICD-9 diagnostic codes for uncomplicated neck pain (UNP) and complicated neck pain (CNP). Results Care patterns with single-provider types and no referrals incurred the least average charges for both UNP and CNP. When care did not include referral providers or services, for either UNP or CNP, MD care with PT was generally less expensive than MD care with DC care. However, when care involved referral providers or services, MD and PT care was on average more expensive than MD and DC care for either UNP or CNP. Risk-adjusted charges for patients in the middle quintile of risk (available 2006-2009) were lower for chiropractic patients with or without medical care or referral care to other providers. Conclusions Chiropractic care alone or DC with MD care incurred appreciably fewer charges for UNP or CNP compared to MD care with or without PT care, when care included referral providers or services. This finding was reversed when care did not include referral providers or services. Risk-adjusted charges for UNP and CNP patients were lower for DC care patterns. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
28. U-Pb zircon geochronology of rocks from west Central Sulawesi, Indonesia: Extension-related metamorphism and magmatism during the early stages of mountain building.
- Author
-
Hennig, Juliane, Hall, Robert, and Armstrong, Richard A.
- Abstract
Sulawesi has generally been interpreted as the product of convergence in the Cretaceous and Cenozoic, and high mountains in west Central Sulawesi have been considered the product of magmatism and metamorphism related to Neogene collision. New SHRIMP and LA-ICP-MS U-Pb zircon dating of metamorphic and granitoid rocks has identified protoliths and sources of melts, and indicates an important role for extension. Schists, gneisses and granitoids have inherited Proterozoic, Paleozoic, Mesozoic and Paleogene zircons. Mesoproterozoic and Triassic age populations are similar to those from the Bird’s Head region. Their protoliths included sediments and granitoids interpreted as part of an Australian-origin block. We suggest this rifted from the Australian margin of Gondwana in the Jurassic and accreted to Sundaland to form NW Sulawesi in the Late Cretaceous. Some metamorphic rocks have Cretaceous and/or Late Eocene magmatic zircons indicating metamorphism cannot be older than Late Eocene, and were not Australian-origin basement. Instead, they were metamorphosed in the Neogene after Sula Spur collision and subsequent major extension. Associated magmatism in west Central Sulawesi produced a K-rich shoshonitic (HK) suite in the Middle Miocene to Early Pliocene. A later episode of magmatism in the Late Miocene to Pliocene formed mainly shoshonitic to high-K calc-alkaline (CAK) rocks. I-type and silica-rich I-type granitoids and diorites of the CAK suite record a widespread short interval of magmatism between 8.5 and 4 Ma. Inherited zircon ages indicate the I-type CAK rocks were the product of partial melting of the HK suite. S-type CAK magmatism between c. 5 and 2.5 Ma and zircon rim ages from gneisses record contemporaneous metamorphism that accompanied extension. Despite its position in a convergent setting in Indonesia, NW Sulawesi illustrates the importance of melting and metamorphism in an extensional setting during the early stages of mountain building. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
29. Structural Dynamics of 15-Lipoxygenase-2 via Hydrogen–Deuterium Exchange
- Author
-
Droege, Kristin D., Keithly, Mary E., Sanders, Charles R., Armstrong, Richard N., and Thompson, Matthew K.
- Abstract
Eicosanoids are inflammatory signaling lipids that are biosynthesized in response to cellular injury or threat. They were originally thought to be pro-inflammatory molecules, but members of at least one subclass, the lipoxins, are able to resolve inflammation. One step in lipoxin synthesis is the oxygenation of arachidonic acid by 15-lipoxygenase (15-LOX). 15-LOX contains two domains: a Ca2+binding PLAT domain and a catalytic domain. 15-LOX is a soluble cytosolic protein until binding of Ca2+to the PLAT domain promotes translocation to the membrane surface. The role of 15-LOX structural dynamics in this translocation has remained unclear. We investigated the dynamics of 15-LOX isoform B (15-LOX-2) upon binding of Ca2+and ligands, as well as upon membrane association using hydrogen–deuterium exchange mass spectrometry (HDX-MS). We used HDX-MS to probe the solvent accessibility and backbone flexibility of 15-LOX-2, revealing significant differences in deuterium incorporation between the PLAT and catalytic domains, with the PLAT domain demonstrating higher flexibility. Comparison of HDX for 15-LOX-2 in the presence and absence of Ca2+indicates there are few differences in structural dynamics. Furthermore, our HDX results involving nanodisc-associated 15-LOX-2 suggest that significant structural and dynamic changes in 15-LOX-2 are not required for membrane association. Our results also show that a substrate lipid binding to the active site in the catalytic domain does induce changes in incorporation of deuterium into the PLAT domain. Overall, our results challenge the previous hypothesis that Ca2+binding induces major structural changes in the PLAT domain and support the hypothesis that is interdomain communication in 15-LOX-2.
- Published
- 2017
- Full Text
- View/download PDF
30. Dissolved black carbon in the global cryosphere: Concentrations and chemical signatures
- Author
-
Khan, Alia L., Wagner, Sasha, Jaffe, Rudolf, Xian, Peng, Williams, Mark, Armstrong, Richard, and McKnight, Diane
- Abstract
Black carbon (BC) is derived from the incomplete combustion of biomass and fossil fuels and can enhance glacial recession when deposited on snow and ice surfaces. Here we explore the influence of environmental conditions and the proximity to anthropogenic sources on the concentration and composition of dissolved black carbon (DBC), as measured by benzenepolycaroxylic acid (BPCA) markers, across snow, lakes, and streams from the global cryosphere. Data are presented from Antarctica, the Arctic, and high alpine regions of the Himalayas, Rockies, Andes, and Alps. DBC concentrations spanned from 0.62 μg/L to 170 μg/L. The median and (2.5, 97.5) quantiles in the pristine samples were 1.8 μg/L (0.62, 12), and nonpristine samples were 21 μg/L (1.6, 170). DBC is susceptible to photodegradation when exposed to solar radiation. This process leads to a less condensed BPCA signature. In general, DBC across the data set was composed of less polycondensed DBC. However, DBC from the Greenland Ice Sheet (GRIS) had a highly condensed BPCA molecular signature. This could be due to recent deposition of BC from Canadian wildfires. Variation in DBC appears to be driven by a combination of photochemical processing and the source combustion conditions under which the DBC was formed. Overall, DBC was found to persist across the global cryosphere in both pristine and nonpristine snow and surface waters. The high concentration of DBC measured in supraglacial melt on the GRIS suggests that DBC can be mobilized across ice surfaces. This is significant because these processes may jointly exacerbate surface albedo reduction in the cryosphere. Here we present dissolved black carbon (DBC) results for snow and glacial melt systems in Antarctica, the Arctic, and high alpine regions of the Himalayas, Rockies, Andes, and Alps. Across the global cryosphere, DBC composition appears to be a result of photochemical processes occurring en route in the atmosphere or in situ on the snow or ice surface, as well as the combustion conditions under which the DBC was formed. We show that samples from the Greenland Ice Sheet (GRIS) have a distinct molecular chemical signature, consistent with deposition of BC from Canadian wildfires occurring the week before sampling. The concentration range observed in this global cryosphere study indicates significant amounts of DBC persist in both pristine and human‐impacted snow and glacial meltwater. Our results are significant for understanding the controls on meltwater production from glaciers worldwide and the feedbacks between combustion sources, wildfires, and the global cryosphere. Wildfires are predicted to increase due to climate change, and albedo cannibalism is already influencing meltwater generation on the GRIS. Anticipated longer summer melt seasons as a result of climate change may result in longer durations between snowfalls, enhancing exposure of recalcitrant DBC on snow/ice surfaces, which could further exacerbate surface albedo reduction in the cryosphere. Dissolved black carbon (DBC) concentrations across the global cryosphere are low, with the exception of snow and surface waters near local sourcesSamples collected from the Greenland Ice Sheet were enriched in highly condensed DBC, relative to other samples from the global cryosphereDBC composition across the cryosphere is influenced by photodegradative processing and combustion conditions under which it was formed
- Published
- 2017
- Full Text
- View/download PDF
31. Global Kinetic Mechanism of Microsomal Glutathione Transferase 1 and Insights into Dynamic Enzyme Activation
- Author
-
Spahiu, Linda, Ålander, Johan, Ottosson-Wadlund, Astrid, Svensson, Richard, Lehmer, Carina, Armstrong, Richard N., and Morgenstern, Ralf
- Abstract
Microsomal glutathione transferase 1 (MGST1) has a unique ability to be activated, ≤30-fold, by modification with sulfhydryl reagents. MGST1 exhibits one-third-of-the-sites reactivity toward glutathione and hence heterogeneous binding to different active sites in the homotrimer. Limited turnover stopped-flow kinetic measurements of the activated enzyme allowed us to more accurately determine the KDfor the “third” low-affinity GSH binding site (1.4 ± 0.3 mM). The rate of thiolate formation, k2(0.77 ± 0.06 s–1), relevant to turnover, could also be determined. By deriving the steady-state rate equation for a random sequential mechanism for MGST1, we can predict KM, kcat, and kcat/KMvalues from these and previously determined pre-steady-state rate constants (all determined at 5 °C). To assess whether the pre-steady-state behavior can account for the steady-state kinetic behavior, we have determined experimental values for kinetic parameters at 5 °C. For reactive substrates and the activated enzyme, data for the microscopic steps account for the global mechanism of MGST1. For the unactivated enzyme and more reactive electrophilic substrates, pre-steady-state and steady-state data can be reconciled only if a more active subpopulation of MGST1 is assumed. We suggest that unactivated MGST1 can be partially activated in its unmodified form. The existence of an activated subpopulation (approximately 10%) could be demonstrated in limited turnover experiments. We therefore suggest that MSGT1 displays a preexisting dynamic equilibrium between high- and low-activity forms.
- Published
- 2017
- Full Text
- View/download PDF
32. Pathology of the Superior Colliculus in Chronic Traumatic Encephalopathy
- Author
-
Armstrong, Richard A., McKee, Ann C., and Cairns, Nigel J.
- Published
- 2017
- Full Text
- View/download PDF
33. Staphylococcus aureus CstB Is a Novel Multidomain Persulfide Dioxygenase-Sulfurtransferase Involved in Hydrogen Sulfide Detoxification.
- Author
-
Jiangchuan Shen, Keithly, Mary E., Armstrong, Richard N., Higgins, Khadine A., Edmonds, Katherine A., and Giedroc, David P.
- Published
- 2015
- Full Text
- View/download PDF
34. Seismic Design of Pile Foundations for Liquefaction Effects.
- Author
-
Ansal, Atilla, Pitilakis, Kyriazis D., Boulanger, Ross W., Chang, Dongdong, Brandenberg, Scott J., Armstrong, Richard J., and Kutter, Bruce L.
- Abstract
Procedures for the seismic design of pile foundations for liquefaction effects are presented with emphasis on the conditions relevant to bridges. Two local subsystems for a bridge are discussed in detail: (1) pile groups in laterally spreading ground away from the abutments and (2) pile groups at the abutments where the restraining or "pinning" effects of the piles and bridge superstructure can be advantageous. The recommended design procedures involve equivalent static analyses using beam on nonlinear Winkler foundation models. Guidance for these design procedures was derived from a combination of dynamic centrifuge model tests and associated nonlinear dynamic finite element studies. The design procedures, their basis, and other issues for design of bridges for liquefaction effects are discussed. [ABSTRACT FROM AUTHOR]
- Published
- 2007
- Full Text
- View/download PDF
35. Neural Stem Cell Technology as a Novel Treatment for Parkinson's Disease.
- Author
-
Walker, John M., Maral Mouradian, M., Armstrong, Richard J.E., Rosser, Anne E., Dunnett, Stephen B., and Barker, Roger A.
- Abstract
The transplantation of human fetal ventral mesencephalic (VM) tissue for patients with advanced Parkinson's disease (PD) has now proved to be of benefit in early clinical trials (1-3). This has been clearly seen in terms of improved motor function, which has been correlated with increased fluorodopa signal on positron emission tomographic scanning at the site of the implant and the presence of abundant tyrosine hydroxylase (TH)-positive neurons in those patients who have come to postmortem analysis (4,5). However, although the concept of restoration of function through neural transplantation is promising, there are major practical as well as ethical problems with the use of aborted human fetal tissue. In particular, aborted fetal tissue is not available in many countries, and even where it can be obtained, isolation of the VM from the large numbers of fetuses the procedure requires presents major logistical difficulties. For example, in PD the best results have been obtained using an average of six to eight fetuses per patient. Therefore, the search for alternative sources of tissue for transplantation is imperative if the procedure is to be widely adopted in the clinical domain. A number of possibilities are currently being explored experimentally (see Table 1), although all of them present difficulties that must be overcome before they can be adopted clinically (reviewed in ref. 6). [ABSTRACT FROM AUTHOR]
- Published
- 2001
- Full Text
- View/download PDF
36. Investigating the presence of foreigners and pig husbandry in ancient Bali: Stable isotopes in human and domestic animal tooth enamel
- Author
-
Fenner, Jack N., Gagan, Michael K., Cowley, Joan, Armstrong, Richard, and Prasetyo, Bagyo
- Abstract
Archaeological excavations at the Sembiran and Pacung archaeological sites in coastal Bali, Indonesia, have yielded pottery sherds and other material culture that derives from India and other locations on the Asian mainland, demonstrating that about 2000years ago the north coast of Bali was in contact with cultures from mainland Asia. The area may in fact have hosted a harbour and perhaps even a community of foreign traders or immigrants. The Sembiran and Pacung excavations also yielded human remains from the same time period. We performed strontium, oxygen and carbon stable isotope analyses of tooth enamel from nine human skeletons to investigate whether the people interred at Sembiran and Pacung were from the local area or had travelled there from a distant home. Strontium isotope ratios were also measured in seven archaeological pig (Suscf. scrofa) teeth, one archaeological canid tooth, and five modern snail (Achatina fulica) shells to help identify the local strontium isotope signature. The people interred at Pacung and Sembiran had similar oxygen and carbon isotope ratios but varying strontium isotope ratios which were higher than expected based on geology. Despite the abundance of foreign materials recovered, our isotope data can be most parsimoniously explained as deriving from a group of locally raised individuals who had a varying mix of coastal and inland plant resources in their diets. In addition, strontium isotope ratios from the pig teeth show interesting clustering, suggesting that two or three different husbandry practices may have been employed.
- Published
- 2016
- Full Text
- View/download PDF
37. A comprehensive chronology of the Neanderthal site Moula-Guercy, Ardèche, France
- Author
-
Willmes, Malte, Grün, Rainer, Douka, Katerina, Michel, Véronique, Armstrong, Richard A., Benson, Alexa, Crégut-Bonnoure, Evelyne, Desclaux, Emmanuel, Fang, Fang, Kinsley, Leslie, Saos, Thibaud, and Defleur, Alban R.
- Abstract
The Baume (cave) Moula-Guercy, in southeast France, contains an important sedimentary sequence, which includes the remains of a cannibalised group of Neanderthals. The chronology of the upper layers of the cave is currently constrained by a thermoluminescence date of 72±12ka, obtained from a tephra deposit (layer VI). The middle and lower layers of the cave have been constrained by biostratigraphy, pointing towards the end of MIS 5 for the Neanderthal bearing layer XV. In order to refine the chronology of the site, we applied radiocarbon, 40Ar/39Ar, U-series and ESR dating analyses. Radiocarbon dates on bone samples from layer IV showed ages older than 50ka. 40Ar/39Ar dating on sanidines from tephra of layer VI revealed, that these volcanic minerals derived probably from the Hercynian basement, and thus provided no tangible chronological constrain. Combined CSUS/ESR results on faunal teeth place layer IV at the end of MIS 3 to MIS 4, in agreement with the radiocarbon dates and in stratigraphic order with the thermoluminescence age for layer VI. Layer VIII, with only one sample, is tentatively placed to the end of MIS 4. The age estimates for layer XIV are not conclusive, preventing an age estimation for this layer. The younger age result for layer XIV does not agree with the stratigraphy and biostratigraphy of the site and more direct dating of material from this layer is needed to resolve this discrepancy. Located just below, the crucial Neanderthal bearing layer XV is placed to the end of MIS 5 and younger than MIS 6, in agreement with the climatological and chronological deductions from the stratigraphy and biostratigraphy of the site. Direct U-series analyses on two Neanderthal teeth agree with an age for layer XV corresponding to at least MIS 5 sensu lato. The U-series results on the Neanderthal tooth 3525 show that U-mobilisation even into small teeth is highly complex, but nevertheless give an indication that this sample corresponds to MIS 5e. This is in agreement with the CSUS/ESR results from faunal teeth as well as the stratigraphy and biostratigraphy of the cave. The refined chronology corroborates the existing stratigraphic and biostratigraphic framework. Moula-Guercy layer XV, with its many human remains showing cannibalism, now stands as a reference site for this particular aspect of human behaviour.
- Published
- 2016
- Full Text
- View/download PDF
38. Practical Considerations in the Use of Liquefaction Susceptibility Criteria
- Author
-
Armstrong, Richard J. and Malvick, Erik J.
- Abstract
Several criteria are available in practice to assess the liquefaction susceptibility of soils. Examples are the so-called Chinese Criteria and more recent criteria, such as Andrews and Martin (2000), Seed et al. (2003), Bray and Sancio (2006), and Boulanger and Idriss (2006). Many of these criteria utilize different soil indices, behavioral states, and limiting values, which make the use of the various criteria in practice confusing at times. The purpose of this paper is to provide practical considerations in the use of three of the most recent and commonly used liquefaction susceptibility criteria—Seed et al. 2003, Bray and Sancio 2006, and Boulanger and Idriss 2006—by addressing three questions often asked in practice: (1) What soils can liquefaction susceptibility criteria be used? (2) What information is provided by liquefaction susceptibility criteria? (3) What is the best use of liquefaction susceptibility criteria?
- Published
- 2016
- Full Text
- View/download PDF
39. RNA-sequencing analysis of core binding factor AML identifies recurrent ZBTB7A mutations and defines RUNX1-CBFA2T3 fusion signature
- Author
-
Lavallée, Vincent-Philippe, Lemieux, Sébastien, Boucher, Geneviève, Gendron, Patrick, Boivin, Isabel, Armstrong, Richard N., Sauvageau, Guy, and Hébert, Josée
- Published
- 2016
- Full Text
- View/download PDF
40. RNA-sequencing analysis of core binding factor AML identifies recurrent ZBTB7Amutations and defines RUNX1-CBFA2T3fusion signature
- Author
-
Lavallée, Vincent-Philippe, Lemieux, Sébastien, Boucher, Geneviève, Gendron, Patrick, Boivin, Isabel, Armstrong, Richard N., Sauvageau, Guy, and Hébert, Josée
- Published
- 2016
- Full Text
- View/download PDF
41. South China continental margin signature for sandstones and granites from Palawan, Philippines.
- Author
-
Suggate, Simon M., Cottam, Michael A., Hall, Robert, Sevastjanova, Inga, Forster, Margaret A., White, Lloyd T., Armstrong, Richard A., Carter, Andrew, and Mojares, Edwin
- Abstract
Abstract: We report results of heavy mineral analysis and U–Pb dating of detrital zircons from metasediments and Cenozoic sandstones, and U–Pb dating of zircons from Cenozoic granites of the North Palawan Continental Terrane (NPCT) and the South Palawan Terrane (SPT). The NPCT metasediments are derived mainly from granitic and metamorphic rocks of continental character. They contain zircons that indicate a maximum depositional age of Late Cretaceous and other age populations indicating a South China origin. The sediments were deposited on the South China margin before rifting of the continental margin during opening of the South China Sea. Miocene SPT sandstones contain similar heavy mineral assemblages suggesting sources that included NPCT metasediments, metamorphic basement rocks at the contact between the SPT and the NPCT, South China Sea rift volcanic and/or minor intrusive rocks, and the Palawan ophiolite complex. The SPT sandstones are very similar to Lower Miocene Kudat Formation sandstones of northern Borneo suggesting a short-lived episode of sediment transport from Palawan to Borneo in the Early Miocene following arc-continent collision. U–Pb dating of zircons shows that the Central Palawan granite is Eocene (42±0.5Ma). The Capoas granite was intruded during a single pulse, or as two separate pulses, between 13.8±0.2Ma and 13.5±0.2Ma. Inherited zircon ages from the Capoas granite imply melting of continental crust derived from the South China margin with a contribution from Cenozoic rift-related and arc material. [Copyright &y& Elsevier]
- Published
- 2014
- Full Text
- View/download PDF
42. New constraints on the Jurassic–Cretaceous boundary in the High Andes using high-precision U–Pb data.
- Author
-
Vennari, Verónica V., Lescano, Marina, Naipauer, Maximiliano, Aguirre-Urreta, Beatriz, Concheyro, Andrea, Schaltegger, Urs, Armstrong, Richard, Pimentel, Marcio, and Ramos, Victor A.
- Abstract
Abstract: The Jurassic–Cretaceous (J–K) boundary is poorly constrained, and is the only Phanerozoic system boundary that lacks an internationally accepted reference stratigraphic section (GSSP). Precise radio-isotopic U–Pb data are unavailable for the earliest stage of the Cretaceous— the Berriasian. The age of the Jurassic–Cretaceous boundary was based on several assumptions, including the relative duration of ammonite zones, the constant spreading rates of magnetic anomalies, and the extrapolation of Rb–Sr or K–Ar isotopic data. This paper discusses a site in an Andean Basin of Western Gondwana showing the J–K boundary interval with geographically widespread nannofossil markers which are here uniquely combined with precise radiometric dates. The recent finding of a sequence of marine black shales in the High Andes of Argentina, interbedded with ash-fall tuffs, provides important constraints on this boundary. This succession bears calcareous nannofossils and ammonites, which allow correlation with well-established Tethyan floras and faunas in the northern hemisphere. The Tithonian–Berriasian transition in the Andes was recognized on the basis of ammonite zones and nannofossil bioevents for the first time in the southern hemisphere. The new ages obtained are 137.9±0.9Ma by sensitive high-resolution ion microprobe (SHRIMP), and 139.55±0.09/0.18Ma by chemical-abrasion isotope-dilution thermal ionization mass spectrometry (TIMS) near the base of the Berriasian. These new ages can be interpreted in two different ways. The first alternative would indicate that the present geological time table is correct and the fossil levels should be late Berriasian. The second alternative is that the J–K boundary is 5Ma younger than the recently published geological time scale. The authors support the last alternative and propose that the J–K boundary should be close to 140Ma. [Copyright &y& Elsevier]
- Published
- 2014
- Full Text
- View/download PDF
43. Structure and Function of the Genomically Encoded Fosfomycin Resistance Enzyme, FosB, from Staphylococcus aureus.
- Author
-
Thompson, Matthew K., Keithly, Mary E., Goodman, Michael C., Hammer, Neal D., Cook, Paul D., Jagessar, Kevin L., Harp, Joel, Skaar, Eric P., and Armstrong, Richard N.
- Published
- 2014
- Full Text
- View/download PDF
44. Structural and Chemical Aspects of Resistance to the Antibiotic Fosfomycin Conferred by FosB from Bacillus cereus.
- Author
-
Thompson, Matthew K., Keithly, Mary E., Harp, Joel, Cook, Paul D., Jagessar, Kevin L., Sulikowski, Gary A., and Armstrong, Richard N.
- Published
- 2013
- Full Text
- View/download PDF
45. Genetic risk factors and age-related macular degeneration (AMD).
- Author
-
Mousavi, Maryam and Armstrong, Richard A.
- Subjects
DISEASES in older people ,RETINAL degeneration ,BLINDNESS ,GENETICISTS ,OPHTHALMOLOGISTS ,OPTOMETRISTS ,IMMUNE system - Abstract
Copyright of Journal of Optometry is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2013
- Full Text
- View/download PDF
46. POLYOLS IN THE CRUSTOSE LICHEN RHIZOCARPON GEOGRAPHICUM.
- Author
-
Armstrong, Richard A.
- Subjects
POLYOLS ,LICHENS ,RHIZOCARPON ,MUTUALISM (Biology) ,PHOTOSYNTHESIS ,ARABITOL ,GAS chromatography - Abstract
A lichen is an intimate association between an alga and a fungus and is regarded as one of the best examples of 'mutualism' or 'symbiosis' involving microorganisms. In lichens which have Trebouxia as the algal partner, photosynthesis by the algae results in the production of the soluble polyol ribitol which is then transported to the fungus where it is converted to arabitol and mannitol. Within the fungus, arabitol may act as a shortterm carbohydrate reserve while mannitol may be involved in stress resistance. The crustose lichen Rhizocarpon geographicum (L.) DC., has an unusual thallus structure consisting of discrete granules (areolae) containing the algal component growing in association with a non-lichenised fungal hypothallus that extends beyond the areolae to form a marginal ring. The concentrations of ribitol, arabitol, and mannitol were measured, using gas chromatography, in the central areolae and marginal hypothallus of the crustose lichen Rhizocarpon geographicum (L.) DC. growing on slate rocks in north Wales, UK. The concentrations of all three polyols were greater in the central areolae than in the marginal hypothallus. In addition, the ratios of polyols in the marginal hypothallus to that in the central areolae varied through the year. The concentration of an individual poyol in the hypothallus was correlated primarily with the concentrations of the other polyols in the hypothallus and not to their concentrations in the areolae. Low concentration of ribitol, arabitol, and mannitol in the marginal hypothallus compared with the central areolae suggests either a lower demand for carbohydrate by the hypothallus or limited transport of polyols from areolae to hypothallus, and may explain the low growth rates of this species. In addition, polyols appear to be partitioned differently through the year with an increase in mannitol compared with arabitol in more stressful periods. [ABSTRACT FROM AUTHOR]
- Published
- 2013
47. Unravelling a Proterozoic basin history through detrital zircon geochronology: The case of the Espinhaço Supergroup, Minas Gerais, Brazil.
- Author
-
Chemale, Farid, Dussin, Ivo A., Alkmim, Fernando F., Martins, Maximiliano Sousa, Queiroga, Gláucia, Armstrong, Richard, and Santos, Marcelo N.
- Subjects
PROTEROZOIC Era ,ZIRCON ,GEOLOGICAL time scales ,CRATONS ,LEAD isotopes - Abstract
Abstract: New U–Pb in situ zircon dating provides a new approach for the study of the Espinhaço Supergroup units exposed in the São Francisco Craton and Araçuaí Orogen. Located in Southern Espinhaço, Minas Gerais, the following two basins were formed in intraplate conditions: (i) the Lower Espinhaço Basin is marked by a volcano-sedimentary sequence with alluvial, fluvial and eolian deposits that were formed from 1.68Ga to 1.80Ga; (ii) the overlying sequence, called the Upper Espinhaço Basin, is a rift-sag basin that presents basal diamond-bearing continental deposits (the Sopa–Brumadinho Formation) with a younger zircon peak at 1192Ma, which is the maximum age for deposition of the upper units. The obtained U–Pb detrital zircon data of the studied units show age groupings related to the orogenic cycles of Jequié (Neoarchean) and Transamazonian (Paleoproterozoic), which are associated with the stability period from 1.8Ga to 0.91Ga in the São Franscico Craton, and record deposition during at least the three basinal cycles. The Stenian–Tonian ages of the Upper Espinhaço Basin units (906Ma to 1192Ma) suggest a direct link with the evolution of the Rodinia Supercontinent and represent a marker for Mesoproterozoic to Early Neoproterozoic evolution in the São Franscico Craton and adjacent areas. [Copyright &y& Elsevier]
- Published
- 2012
- Full Text
- View/download PDF
48. Observation of Two Modes of Inhibition of Human Microsomal Prostaglandin E Synthase 1 by the Cyclopentenone 15-Deoxy-Δ12,14-prostaglandin J2.
- Author
-
Prage, Edward B., Morgenstern, Ralf, Jakobsson, Per-Johan, Stec, Donald F., Voehler, Markus W., and Armstrong, Richard N.
- Published
- 2012
- Full Text
- View/download PDF
49. Myristoylation Exerts Direct and Allosteric Effects on Gα Conformation and Dynamics in Solution.
- Author
-
Preininger, Anita M., Kaya, Ali I., Gilbert, James A., Busenlehner, Laura S., Armstrong, Richard N., and Hamm, Heidi E.
- Published
- 2012
- Full Text
- View/download PDF
50. 530Ma syntectonic syenites and granites in NW Namibia — Their relation with collision along the junction of the Damara and Kaoko belts.
- Author
-
Schmitt, Renata S., Trouw, Rudolph A.J., Passchier, Cees W., Medeiros, Silvia R., and Armstrong, Richard
- Subjects
ZIRCON ,MICA ,GEODYNAMICS ,METAMORPHISM (Geology) ,OROGENIC belts ,HORNBLENDE ,KAOKO Belt (Namibia) - Abstract
Abstract: The Lower Ugab and Goantagab structural domains are located at the junction between the N–S trending Kaoko and the E–W trending Damara belts (NW Namibia), where Neoproterozoic metavolcano-sedimentary sequences were intruded by several syenitic/granitic plutons. We present here new U–Pb ages on zircon grains from the Voetspoor and Doros plutons. Together with petrological, geochemical and structural data we evaluate the timing of the deformation and relation to the geodynamics during the final stage of Gondwana amalgamation. The plutons are composed of three main rock types: hornblende quartz-syenite, syenodiorite and biotite granite. The two former are predominant and show genetic correlation such as magma mingling structures and similar geochemical signatures. The biotite granite occurs in the SW parts of the intrusions and clearly cuts the syenitic rocks. Although the plutons are mainly isotropic, the structures around them demonstrate that their intrusion occurred during a second deformation phase (D2) with a component of sinistral solid state rotation with respect to the wall rocks in response to D2 transpression. Four samples were dated using U–Pb SHRIMP methodology in single zircon grains. A hornblende monzodiorite from the Voetspoor pluton yielded an age of 534±4.5Ma. A hornblende monzonite from the Doros pluton produced an age of 528±5Ma. The biotite granite facies was sampled in the Doros intrusion and yielded an age of 530±4.5Ma. In addition, a granitic vein folded by D2 close to the northeastern contact of the Doros pluton with the encasing phyllites (Amis River Formation) was also dated, yielding an age of 533±6Ma. The data show that all granite–syenite from Doros and Voetspoor intrusions are contemporaneous and crystallized in the period between 539 and 522Ma within the errors. D1–D2 deformational phases took place under greenschist facies (biotite zone) conditions and during D3 the metamorphic grade was slightly lower. We interpret that the plutons are coeval to peak metamorphism of the region (530–520Ma) and that D2 and D3 sinistral transpressional phases are due to collision in the Damara Belt. The E–W compressional event and second metamorphic episode in the Kaoko Belt occurred between 580 and 560Ma and are apparently unrelated to the thermo-tectonic evolution described here, although D1 might be partially related to this event. The sinistral transpressional D2 phase resulted probably from the position of the area considered at the junction between the belts, and not in the frontal Damara collision further to the east. This new interpretation is consistent with the Ar–Ar ages for the region (about 500Ma), interpreted to reflect cooling of the orogen. The enrichment in LREE, K, Rb, Ba and Sr, and depletion in Nb of these basic to intermediate alkalic rocks could indicate that they partially derived from melting of a subcontinental lithospheric mantle that was affected by subduction and the granitic rock types represent lower crust contamination. We interpret that they could be related to heating in the mantle caused by asthenosphere influx in a zone of slab-breakoff during collision between Kalahari and Congo cratons. [Copyright &y& Elsevier]
- Published
- 2012
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.