ALBERT

Description: We have constructed an alternating-field (AF) demagnetizer with a magnetic core in a passively air-cooled coil that can routinely operate at fields up to 0.5 tesla, almost three times higher than we could attain before in our commercial instrument. The field is powered by a commercial 1 kW power amplifier and is transverse to the bore, uniform to ±2% over a 25 mm paleomagnetic sample, and compatible with our existing sample handler for automated demagnetization and measurement. Even harmonics are ≤1 ppm of the fundamental and so generate negligible anhysteretic remanence. The much higher peak alternating field, 2 and 5 times that commonly available in air-core solenoidal and Helmhotz coil configurations, respectively, enables successful AF demagnetization of many samples that could not be completely demagnetized with commercially available equipment. This capability is especially useful for high-coercivity sedimentary and igneous rocks and extra-terrestrial materials that contain magnetic minerals that alter during thermal demagnetization. In addition to the benefits this instrument brings to our own research, a much broader potential impact is that it could replace the transverse coils of most automated AF demagnetization systems in use today, whether for discrete or continuous U-channel measurements, which are commonly limited to peak fields of ∼100 mT. Manual and tumbling demagnetizers would benefit as well by the ∼2-times increase in maximum field over those that can be attained by commercial solenoidal coils. Furthermore, we expect that it and similarly designed magnetic-core instruments will be capable of attaining even higher fields, of order 1 tesla. This article is protected by copyright. All rights reserved.

Description: In this paper, we present paleomagnetic, geochemical, mineralogical, and geochronologic evidence for correlation of the mid-Miocene Cougar Point Tuff (CPT) in southwest Snake River Plain (SRP) of Idaho. The new stratigraphy presented here significantly reduces the frequency and increases the scale of known SRP ignimbrite eruptions. The CPT section exposed at the Black Rock Escarpment along the Bruneau river has been correlated eastward to the Brown's Bench escarpment (6 common eruption-units) and Cassia Mountains (3 common eruption-units) regions of southern Idaho. The CPT record an unusual pattern of geomagnetic field directions that provides the basis for robust stratigraphic correlations. Paleomagnetic characterization of eruption-units based on geomagnetic field variation has a resolution on the order of a few centuries, providing a strong test of whether two deposits could have been emplaced from the same eruption or from temporally separate events. To obtain reliable paleomagnetic directions, the anisotropy of anhysteretic remanence was measured to correct for magnetic anisotropy, and an efficient new method was used to remove gyroremanence acquired during alternating field demagnetization.

Description: SUMMARY Geomagnetic polarity transitions may be significantly more complex than are currently depicted in many sedimentary and lava-flow records. By splicing together paleomagnetic results from earlier studies at Steens Mountain with those from three newly studied sections of Oregon Plateau flood basalts at Catlow Peak and Poker Jim Ridge 70–90 km to the southeast and west, respectively, we provide support for this interpretation with the most detailed account of a magnetic field reversal yet observed in volcanic rocks. Forty-five new distinguishable transitional (T) directions together with 30 earlier ones reveal a much more complex and detailed record of the 16.7 Ma reversed (R)-to-normal (N) polarity transition that marks the end of Chron C5Cr. Compared to the earlier R-T-N-T-N reversal record, the new record can be described as R-T-N-T-N-T-R-T-N. The composite record confirms earlier features, adds new west and up directions and an entire large N-T-R-T segment to the path, and fills in directions on the path between earlier directional jumps. Persistent virtual geomagnetic pole (VGP) clusters and separate VGPs have a preference for previously described longitudinal bands from transition study compilations, which suggests the presence of features at the core–mantle boundary that influence the flow of core fluid and distribution of magnetic flux. Overall the record is consistent with the generalization that VGP paths vary greatly from reversal to reversal and depend on the location of the observer. Rates of secular variation confirm that the flows comprising these sections were erupted rapidly, with maximum rates estimated to be 85–120 m ka −1 at Catlow and 130–195 m ka −1 at Poker Jim South. Paleomagnetic poles from other studies are combined with 32 non-transitional poles found here to give a clockwise rotation of the Oregon Plateau of 11.4°± 5.6° with respect to the younger Columbia River Basalt Group flows to the north and 14.5°± 4.6° with respect to cratonic North America (95 per cent confidence interval).

Description: Individual ignimbrite cooling-units in southern Idaho display significant variation of magnetic remanence directions and other magnetic properties. This complicates paleomagnetic correlation. The ignimbrites are intensely welded and exhibit mylonite-like flow-banding produced by rheomorphic ductile shear during emplacement, prior to cooling below magnetic blocking temperatures. Glassy vitrophyric lithologies commonly have discrepantly shallow remanence directions rotated closer to the orientation of the sub-horizontal shear fabric when compared to the microcrystalline center of the same cooling-unit. To investigate this problem, we conducted a detailed paleomagnetic and rock magnetic study of a vertical profile through a single ignimbrite cooling-unit and its underlying baked soil. The results demonstrate that large anisotropy of thermal remanent magnetization (ATRM) correlates with large (up to 38°) deflections of the stable remanence direction. AMS revealed no strong anisotropy. A strong lineation and deflection of the remanence declination suggest that rheomorphic shear above magnetic blocking temperatures is the dominant mechanism controlling formation of the magnetic fabric, with compaction contributing to a lesser extent. Nucleation and growth of anisotropic fine-grained magnetite in volcanic glass at high temperatures after, and perhaps also during, emplacement is indicated by systematic variation of magnetic properties from the quickly chilled ignimbrite base to the interior. These properties include remanence directions, anisotropy, coercivity, susceptibility, strength of natural remanent magnetization, and dominant unblocking temperature. The microcrystalline ignimbrite center has a magnetic direction that is the same as the underlying baked soil and, therefore, is a more reliable recorder of the paleofield direction than the glassy margins of highly welded ignimbrites.

Description: Uncertainty over the trajectory of seawater oxygenation in the coming decades is of particular concern in the light of geological episodes of abrupt global warming that were frequently accompanied by lowered seawater oxygen concentrations. Here we present an assessment of global seawater oxygenation from an interval of one of these warming episodes, the Paleocene-Eocene Thermal Maximum (PETM, 55.9 m.y. ago). Our results, obtained from Integrated Ocean Drilling Program Expedition 302 Site M0004 in the Arctic Ocean, are based on molybdenum isotope determinations and molybdenum, rhenium, and uranium abundances. These data indicate a small global expansion of low-oxygen marine environments in the upper part of the PETM interval compared with the present day. More extensive seawater deoxygenation may have occurred for as long as ∼100 k.y., associated with a high rate of global warming and carbon oxidation at the start of the PETM. Our data also reveal molybdenum isotope compositions in Arctic Ocean deposits that are outside the range currently documented in marine environments. These exceptional compositions could reflect either the influence of hydrothermal inputs or equilibrium isotope fractionations associated with molybdenum sulfide speciation.

Description: The Parana-Etendeka flood volcanic event produced approximately 1.5 x 10(6) cubic kilometers of volcanic rocks, ranging from basalts to rhyolites, before the separation of South America and Africa during the Cretaceous period. New (40)Ar/(39)Ar data combined with earlier paleomagnetic results indicate that Parana flood volcanism in southern Brazil began at 133 +/- 1 million years ago and lasted less than 1 million years. The implied mean eruption rate on the order of 1.5 cubic kilometers per year is consistent with a mantle plume origin for the event and is comparable to eruption rates determined for other well-documented continental flood volcanic events. Parana flood volcanism occurred before the initiation of sea floor spreading in the South Atlantic and was probably precipitated by uplift and weakening of the lithosphere by the Tristan da Cunha plume. The Parana event postdates most current estimates for the age of the faunal mass extinction associated with the Jurassic-Cretaceous boundary.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Renne, P R -- Ernesto, M -- Pacca, I G -- Coe, R S -- Glen, J M -- Prevot, M -- Perrin, M -- New York, N.Y. -- Science. 1992 Nov 6;258(5084):975-9.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/17794593" target="_blank"〉PubMed〈/a〉

Description: The effect of an increase in atmospheric aerosol concentrations on the distribution and radiative properties of Earth’s clouds is the most uncertain component of the overall global radiative forcing from preindustrial time. General circulation models (GCMs) are the tool for predicting future climate, but the treatment of aerosols, clouds, and...

Description: Static three-axis alternating field (AF) demagnetization is the most common method regularly implemented for removing magnetic components of rock samples. This method is so widely used that one of its main limitations, the acquisition of gyroremanence (GRM), is often not accounted for or even discussed. The presence of GRM likely interferes more than is recognized in accurate determination of the most stable remanence. The accepted method proposed by Dankers and Zjiderveld (1981) for excluding GRM affected measurements requires nearly triple the amount of lab work, and by consequence, is almost never regularly implemented on large batches of samples. Here, we present a laboratory procedure and subsequent analysis (SI method) that removes the effects of GRM in static AF demagnetization without requiring extra laboratory work. This paper, therefore, describes a new standard protocol for efficient static AF demagnetization of rocks. This article is protected by copyright. All rights reserved.

Description: Blood cells derive from hematopoietic stem cells through stepwise fating events. To characterize gene expression programs driving lineage choice, we sequenced RNA from eight primary human hematopoietic progenitor populations representing the major myeloid commitment stages and the main lymphoid stage. We identified extensive cell type-specific expression changes: 6711 genes and 10,724 transcripts, enriched in non-protein-coding elements at early stages of differentiation. In addition, we found 7881 novel splice junctions and 2301 differentially used alternative splicing events, enriched in genes involved in regulatory processes. We demonstrated experimentally cell-specific isoform usage, identifying nuclear factor I/B (NFIB) as a regulator of megakaryocyte maturation-the platelet precursor. Our data highlight the complexity of fating events in closely related progenitor populations, the understanding of which is essential for the advancement of transplantation and regenerative medicine.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4254742/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4254742/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Chen, Lu -- Kostadima, Myrto -- Martens, Joost H A -- Canu, Giovanni -- Garcia, Sara P -- Turro, Ernest -- Downes, Kate -- Macaulay, Iain C -- Bielczyk-Maczynska, Ewa -- Coe, Sophia -- Farrow, Samantha -- Poudel, Pawan -- Burden, Frances -- Jansen, Sjoert B G -- Astle, William J -- Attwood, Antony -- Bariana, Tadbir -- de Bono, Bernard -- Breschi, Alessandra -- Chambers, John C -- BRIDGE Consortium -- Choudry, Fizzah A -- Clarke, Laura -- Coupland, Paul -- van der Ent, Martijn -- Erber, Wendy N -- Jansen, Joop H -- Favier, Remi -- Fenech, Matthew E -- Foad, Nicola -- Freson, Kathleen -- van Geet, Chris -- Gomez, Keith -- Guigo, Roderic -- Hampshire, Daniel -- Kelly, Anne M -- Kerstens, Hindrik H D -- Kooner, Jaspal S -- Laffan, Michael -- Lentaigne, Claire -- Labalette, Charlotte -- Martin, Tiphaine -- Meacham, Stuart -- Mumford, Andrew -- Nurnberg, Sylvia -- Palumbo, Emilio -- van der Reijden, Bert A -- Richardson, David -- Sammut, Stephen J -- Slodkowicz, Greg -- Tamuri, Asif U -- Vasquez, Louella -- Voss, Katrin -- Watt, Stephen -- Westbury, Sarah -- Flicek, Paul -- Loos, Remco -- Goldman, Nick -- Bertone, Paul -- Read, Randy J -- Richardson, Sylvia -- Cvejic, Ana -- Soranzo, Nicole -- Ouwehand, Willem H -- Stunnenberg, Hendrik G -- Frontini, Mattia -- Rendon, Augusto -- 082961/Wellcome Trust/United Kingdom -- 082961/Z/07/Z/Wellcome Trust/United Kingdom -- 084183/Z/07/Z/Wellcome Trust/United Kingdom -- 095908/Wellcome Trust/United Kingdom -- 100140/Wellcome Trust/United Kingdom -- C45041/A14953/Cancer Research UK/United Kingdom -- FS/12/27/29405/British Heart Foundation/United Kingdom -- MC_UP_0801/1/Medical Research Council/United Kingdom -- MR/J011711/1/Medical Research Council/United Kingdom -- MR/K006584/1/Medical Research Council/United Kingdom -- MR/K023489/1/Medical Research Council/United Kingdom -- RG/09/012/28096/British Heart Foundation/United Kingdom -- RG/09/12/28096/British Heart Foundation/United Kingdom -- RP-PG-0310-1002/British Heart Foundation/United Kingdom -- RP-PG-0310-1002/Department of Health/United Kingdom -- WT091310/Wellcome Trust/United Kingdom -- WT098051/Wellcome Trust/United Kingdom -- Medical Research Council/United Kingdom -- New York, N.Y. -- Science. 2014 Sep 26;345(6204):1251033. doi: 10.1126/science.1251033.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, UK. Department of Haematology, University of Cambridge, Cambridge Biomedical Campus, Cambridge CB2 0PT, UK. National Health Service (NHS) Blood and Transplant, Cambridge Biomedical Campus, Cambridge CB2 0PT, UK. ; Department of Haematology, University of Cambridge, Cambridge Biomedical Campus, Cambridge CB2 0PT, UK. European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SD, UK. National Health Service (NHS) Blood and Transplant, Cambridge Biomedical Campus, Cambridge CB2 0PT, UK. ; Department of Molecular Biology, Radboud University, 6525 GA Nijmegen, Netherlands. ; Department of Haematology, University of Cambridge, Cambridge Biomedical Campus, Cambridge CB2 0PT, UK. National Health Service (NHS) Blood and Transplant, Cambridge Biomedical Campus, Cambridge CB2 0PT, UK. ; Sanger Institute-EBI Single-Cell Genomics Centre, Wellcome Trust Sanger Institute, Hinxton, Cambridge CB10 1SA, UK. ; Department of Haematology, University of Cambridge, Cambridge Biomedical Campus, Cambridge CB2 0PT, UK. National Health Service (NHS) Blood and Transplant, Cambridge Biomedical Campus, Cambridge CB2 0PT, UK. Medical Research Council Biostatistics Unit, Cambridge Biomedical Campus, Cambridge CB2 0SR, UK. ; Department of Haematology, University College London Cancer Institute, London WC1E 6DD, UK. The Katharine Dormandy Haemophilia Centre and Thrombosis Unit, Royal Free NHS Trust, London NW3 2QG, UK. ; CHIME Institute, University College London, Archway Campus, London NW1 2DA, UK. Auckland Bioengineering Institute, University of Auckland, Auckland 1010, New Zealand. ; Centre for Genomic Regulation and University Pompeu Fabra, 08002 Barcelona, Spain. ; Imperial College Healthcare NHS Trust, DuCane Road, London W12 0HS, UK. Ealing Hospital NHS Trust, Southall, Middlesex UB1 3HW, UK. ; European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SD, UK. ; Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, UK. ; Pathology and Laboratory Medicine, University of Western Australia, Crawley, Western Australia 6009, Australia. ; Department of Laboratory Medicine, Laboratory of Hematology, Radboud University Medical Center, 6525 GA Nijmegen, Netherlands. ; Assistance Publique-Hopitaux de Paris, INSERM U1009, 94805 Villejuif, France. ; Biomedical Research Centre, Norwich Medical School, University of East Anglia, Norwich NR4 7TJ, UK. ; Center for Molecular and Vascular Biology, University of Leuven, 3000 Leuven, Belgium. ; The Katharine Dormandy Haemophilia Centre and Thrombosis Unit, Royal Free NHS Trust, London NW3 2QG, UK. ; Department of Haematology, University of Cambridge, Cambridge Biomedical Campus, Cambridge CB2 0PT, UK. National Health Service (NHS) Blood and Transplant, Cambridge Biomedical Campus, Cambridge CB2 0PT, UK. Cambridge University Hospitals NHS Foundation Trust, Cambridge Biomedical Campus, Cambridge B2 0QQ, UK. ; Department of Haematology, Hammersmith Campus, Imperial College Academic Health Sciences Centre, Imperial College London, London W12 0HS, UK. ; Department of Haematology, University of Cambridge, Cambridge Biomedical Campus, Cambridge CB2 0PT, UK. National Health Service (NHS) Blood and Transplant, Cambridge Biomedical Campus, Cambridge CB2 0PT, UK. Department of Twin Research & Genetic Epidemiology, Genetics and Molecular Medicine Division, St Thomas' Hospital, King's College, London SE1 7EH, UK. ; School of Cellular and Molecular Medicine, University of Bristol, Bristol BS8 1TD, UK. ; Department of Oncology, Addenbrooke's Cambridge University Hospital NHS Trust, Cambridge Biomedical Campus, Cambridge CB2 0RE, UK. Cancer Research UK, Cambridge Institute, Cambridge Biomedical Campus, Cambridge CB2 0RE, UK. ; National Health Service (NHS) Blood and Transplant, Cambridge Biomedical Campus, Cambridge CB2 0PT, UK. ; School of Clinical Sciences, University of Bristol, Bristol BS2 8DZ, UK. ; European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SD, UK. Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, UK. ; European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SD, UK. Genome Biology and Developmental Biology Units, European Molecular Biology Laboratory, 69117 Heidelberg, Germany. Wellcome Trust-Medical Research Council Stem Cell Institute, University of Cambridge, Cambridge CB2 1QR, UK. ; Department of Haematology, Cambridge Institute for Medical Research, University of Cambridge, Cambridge Biomedical Campus, Cambridge CB2 0XY, UK. ; Medical Research Council Biostatistics Unit, Cambridge Biomedical Campus, Cambridge CB2 0SR, UK. ; Department of Haematology, University of Cambridge, Cambridge Biomedical Campus, Cambridge CB2 0PT, UK. Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, UK. ; Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, UK. Department of Haematology, University of Cambridge, Cambridge Biomedical Campus, Cambridge CB2 0PT, UK. ; Department of Haematology, University of Cambridge, Cambridge Biomedical Campus, Cambridge CB2 0PT, UK. National Health Service (NHS) Blood and Transplant, Cambridge Biomedical Campus, Cambridge CB2 0PT, UK. Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, UK. ; Department of Haematology, University of Cambridge, Cambridge Biomedical Campus, Cambridge CB2 0PT, UK. National Health Service (NHS) Blood and Transplant, Cambridge Biomedical Campus, Cambridge CB2 0PT, UK. ar506@cam.ac.uk mf471@cam.ac.uk. ; Department of Haematology, University of Cambridge, Cambridge Biomedical Campus, Cambridge CB2 0PT, UK. National Health Service (NHS) Blood and Transplant, Cambridge Biomedical Campus, Cambridge CB2 0PT, UK. Medical Research Council Biostatistics Unit, Cambridge Biomedical Campus, Cambridge CB2 0SR, UK. ar506@cam.ac.uk mf471@cam.ac.uk.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/25258084" target="_blank"〉PubMed〈/a〉