2,444 research outputs found
Re-evaluation of the age model for North Atlantic Ocean Site 982 – arguments for a return to the original chronology
No full textRecently, the veracity of the published chronology for the Pliocene section of North Atlantic Ocean Drilling Program Site 982 was called into question. Here, we examine the robustness of the original age model as well as the proposed age model revision. The proposed revision is predicated on an apparent mis-identification of the depth to the Gauss-Matuyama (G/M) polarity chronozone reversal boundary (2.581 Ma) based on preliminary shipboard paleomagnetic data and offers a new chronology which includes a hiatus between ~3.2 and 3 Ma. However, an even more accurate shore-based, u-channel-derived polarity chronozone stratigraphy for the past ~2.7 Ma supports the shipboard composite stratigraphy and demonstrates that the original estimate of the depth of the G/M reversal in the Site 982 record is correct. Thus, the main justification forwarded to support the revised chronology no longer exists. We demonstrate that the proposed revision results in a pronounced anomaly in sedimentation rates proximal to the proposed hiatus, erroneous assignment of marine-isotope stages in the Site 982 Pliocene benthic stable oxygen isotope stratigraphy, and a markedly worse correlation of proxy records between this site and other regional paleoclimate data. We conclude that the original chronology for Site 982 is a far more accurate age-model than that which arises from the published revision. We strongly recommend the use of the original chronology for all future work at Site 982
Planktic foraminifera shell chemistry response to seawater chemistry: Pliocene-Pleistocene seawater Mg/Ca, temperature and sea level change
No full textForaminifera Mg/Ca paleothermometry forms the basis of a substantial portion of ocean temperature reconstruction over the last 5 Ma. Furthermore, coupled Mg/Ca–oxygen isotope (δ18O) measurements of benthic foraminifera can constrain eustatic sea level (ESL) independent of paleo-shoreline derived approaches. However, this technique suffers from uncertainty regarding the secular variation of the Mg/Ca seawater ratio (Mg/Casw) on timescales of millions of years. Here we present coupled seawater–test Mg/Ca–temperature laboratory calibrations of Globigerinoides ruber in order to test the widely held
assumptions that (1) seawater–test Mg/Ca co-vary linearly, and (2) the Mg/Ca–temperature sensitivity remains constant with changing Mg/Casw. We find a nonlinear Mg/Catest–Mg/Casw relationship and a lowering of the Mg/Ca–temperature sensitivity at lower than modern Mg/Casw from 9.0% ◦C−1 at Mg/Casw = 5.2 mol mol−1 to 7.5 ± 0.9%◦C−1 at 3.4 mol mol−1. Using our calibrations to more accurately calculate the offset between Mg/Ca and biomarker-derived paleotemperatures for four sites, we derive a Pliocene
Mg/Casw ratio of ∼4.3 mol mol−1. This Mg/Casw implies Pliocene ocean temperature 0.9–1.9 ◦C higher than previously reported and, by extension, ESL ∼30 m lower compared to when one assumes that Pliocene Mg/Casw is the same as at present. Correcting existing benthic foraminifera datasets for Mg/Casw indicates that deep water source composition must have changed through time, therefore seawater oxygen isotope reconstructions relative to present day cannot be used to directly reconstruct Pliocene ESL
Coming home to mother
No full textGift of Dr. Mary Jane Esplen.Piano vocal [instrumentation]We love to think of years ago [first line]We are coming home to Mother [first line of chorus]A flat [key]Piano [tempo]House, families, birds, photograph of M.E. Mollins [illustration]Popular song [form/genre]Publisher's advertisement on inside front [note]Mediatoon by G.A. Boyton [note
M.E. Church exterior
No full textA monochrome postcard of the M.E. Church in Georgetown, Delaware. The church was made out of brick and had a tall tower on its corner. Writing on the right indicates that the author was having a good time. Mrs. P. H. Adkins of Milton, Delaware, received this postcard. A postmark on the back indicates that this postcard was mailed from Georgetown, Delaware. The postage stamp is a one-cent U.S. #300, Benjamin Franklin. The back of the postcard is labeled 75.00 and 0240
M.E. Church exterior
No full textA monochrome postcard of the M.E. Church in Georgetown, Delaware. The church was made out of brick and had a tall tower on its corner. Writing on the right indicates that the author was having a good time. Mrs. P. H. Adkins of Milton, Delaware, received this postcard. A postmark on the back indicates that this postcard was mailed from Georgetown, Delaware. The postage stamp is a one-cent U.S. #300, Benjamin Franklin. The back of the postcard is labeled 75.00 and 0240
On using Directional Information for Parameter Space Decomposition in Ellipse Detection
No full textIn this paper we use the parametric polar representation to extend the application of edge directional information from circle to ellipse extraction. As a result we obtain a mapping which decomposes the parameter space required for ellipse extraction into two independent sub-spaces and one final histogram accumulator. The mapping includes the tangent of the angle of the first and second directional derivatives. These tangents are computed by considering edge direction at two border points. We show that the use of gradient information for parameter space decomposition avoids the intensive point labelling imposed by geometric constraints used by other approaches
La fecondazione assistita dopo dieci anni di legge 40 : il punto di vista del costituzionalista
No full textThe Author of this paper adds the point of view of the constitutionalist to the debate on the Italian statute n.40/1994 on assisted reproduction illustrated by Flamigni and Mori in their work. The paper ends with a reflection on the recent decision n. 162/2014 issued by the Constitutional Court, which has declared the illegitimacy of the prohibition of heterologous reproduction
L'approvazione della legge Cirinnà : fra riconoscimento dei diritti e scontro ideologico
No full textThe New Italian Law on Civil Unions: Between Rights Recognition and Ideological Clash Abstract: The author examines the coming into force of the first Italian law on civil unions, which, for the first time, grants protection for both homosexual and different sex couples
La Corte costituzionale chiude la porta agli scienziati in nome della dignità dell’embrione
No full textThis essay aims to analize decision no. 84 of 2016 of the Italian Constitu-tional Court, on the matter of scientific research on embryos.
In particular the essay dwells with the problematic acknowledgement of the embryo dignity. The Author considers this aspect in the context of the relation between sci-entific evolution and legislative discretionality, taking into account the other deci-sions of the Court on the matter of medically assisted procreation
Corrigendum: Sea-level and deep-sea-temperature variability over the past 5.3 million years
No full textCorrigendum: In this Article, owing to a misunderstanding of discussions at the PALSEA2 workshop in Rome, we erroneously reported previous sea-level estimates for the period 3.3–2.9 Myr as originating from the ‘Pliocene Maximum Sea Level’ (PLIOMAX) project. However, these estimates are not from PLIOMAX, relating to ref. 3 instead. We thank M. E. Raymo and A. Rovere for drawing the error to our attention. The online versions of the paper have been corrected
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