A Variational Inference based Detection Method for Repetition Coded Generalized Spatial Modulation

In this paper, we consider a simple coding scheme for spatial modulation (SM), where the same set of active transmit antennas is repeatedly used over consecutive multiple transmissions. Based on a Gaussian approximation, an approximate maximum likelihood (ML) detection problem is formulated to detect the indices of active transmit antennas. We show that the solution to the approximate ML detection problem can achieve a full coding gain. Furthermore, we develop a low-complexity iterative algorithm to solve the problem with low complexity based on a well-known machine learning approach, i.e., variational inference. Simulation results show that the proposed algorithm can have a near ML performance. A salient feature of the proposed algorithm is that its complexity is independent of the number of active transmit antennas, whereas an exhaustive search for the ML problem requires a complexity that grows exponentially with the number of active transmit antennas.Comment: 11 pages, 8 figure

Land Law, Property Ideologies and the British-Irish relationship

English and Irish land law are deeply influenced by the historical context of the British-Irish relationship, yet property scholarship comparing the two jurisdictions is surprisingly rare. The current Brexit negotiations provide a timely reminder of the strategic importance of property and trade relations between the two countries; and of their related-but-different legal cultures. In this article we examine how the property cultures of England and Ireland were shaped by the politics and practices of land tenure, by competing economic and property ideologies, and by the influence of both on national identity and statehood in both jurisdictions. The article reveals the role of local contexts and events in shaping land reform, and demonstrates the fertile potential of the comparative frame to contextualise each jurisdiction’s doctrines and practices. As domestic land law systems are drawn together in the context of emerging EU jurisdiction over areas like mortgage credit, each jurisdiction’s underpinning ideological commitments have important implications for the ease – or not – of attempts to harmonize member state practices. We explain the alignments and divergences between domestic underpinnings of Irish and English law, and reflect on the implications of our findings for contemporary property problems in the context of evolving economic and political relationships between the UK and Ireland

Mochras borehole revisited: a new global standard for Early Jurassic earth history

The Early Jurassic epoch was a time of extreme environmental change: there are well-documented examples of rapid transitions from cold, or even glacial, climates to super greenhouse events, the latter characterized worldwide by hugely enhanced organic carbon burial, multiple large isotopic anomalies, global sea-level change, and mass extinction (Price, 1999; Hesselbo et al., 2000; Jenkyns, 2010; Korte and Hesselbo, 2011). These icehouse–greenhouse events not only reflect changes in the global climate system but are also thought to have had significant influence on the evolution of Jurassic marine biota (e.g. van de Schootbrugge et al., 2005; Fraguas et al., 2012). Furthermore, the events may serve as analogues for present-day and future environmental transitions

Initial results of coring at Prees, Cheshire Basin, UK (ICDP JET project): towards an integrated stratigraphy, timescale, and Earth system understanding for the Early Jurassic

This is the final version. Available on open access from Copernicus Publications via the DOI in this recordData availability: Full core scan data (https://doi.org/10.5285/91392f09-25d4-454c-aece-56bde0dbf3ba, BGS Core Scanning Facility, 2022) will be available after 1 November 2024 via the Natural Environment Research Council (NERC) National Geoscience Data Centre (https://webapps.bgs.ac.uk/services/ngdc/accessions/index.html#, last access: 12 October 2023). Downhole logging data (https://doi.org/10.5880/ICDP.5065.001​​​​​​​, Wonik, 2023) will be made available via the ICDP (https://www.icdp-online.org/projects/by-continent/europe/jet-uk/, last access: 12 October 2023). The JET Operational Report is published as Hesselbo et al. (2023); full information about the operational dataset, the logging dataset, data availability and the explanatory remarks is available on the ICPD-JET project website: https://www.icdp-online.org/projects/by-continent/europe/jet-uk/ (last access: 12 October 2023). A subset of data, additional biostratigraphic tables, and vector graphics files for Figs. 3–5 are included as the Supplement. Supplementary Data File 1 tabulates the corrected depth scale for Prees 2C. Supplementary Data File 2 summarizes the ammonite-based chronostratigraphy of the Prees 2 cores (ammonite identifications by Kevin N. Page). Supplementary Data File 3 summarizes the ammonite-based chronostratigraphy for the Hettangian to Early Pliensbachian of the Llanbedr (Mochras Farm) borehole (updated by Kevin N. Page). Supplementary Data File 4 tabulates the organic carbon-isotope ratios, TOC, and carbonate content of low-resolution samples taken at the Prees drill site; TOC and carbonate data are calculated using calibration based on portable XRF (Supplementary Data File 5) and a gas source isotope ratio mass spectrometer (Supplementary Data File 6). Supplementary Data File 5 tabulates portable XRF results for bulk rock powders of low-resolution samples taken at the Prees drill site; uncertainties stated in the table are given for the fit to the raw data and do not reflect the true reproducibility of the data. Empty fields indicate values under the detection limit. Sample SSK116001 acted as a repeat sample which was measured 70 times over the course of the data acquisition to determine the repeatability and drift of the instrument. LE stands for “light elements”. Supplementary Data File 6 tabulates gas source isotope ratio mass spectrometry (GS-IRMS) data (oxygen- and carbon-isotope ratios of carbonate as well as carbonate content calculated as calcite) for a set of 24 samples covering the entire core length and reflecting a representative spread of carbonate content. Comparison of GS-IRMS data with p-XRF data was used to create a calibration curve to calculate the carbonate (and TOC) content of all low-resolution samples. Supplementary Data File 7 tabulates pyrolysis data (Rock-Eval 6) for Prees 1 well cuttings and Wilkesley borehole samples. Supplementary Data File 8 contains vector graphics files (.svg) for Figs. 3–5.Drilling for the International Continental Scientific Drilling Program (ICDP) Early Jurassic Earth System and Timescale project (JET) was undertaken between October 2020 and January 2021. The drill site is situated in a small-scale synformal basin of the latest Triassic to Early Jurassic age that formed above the major Permian–Triassic half-graben system of the Cheshire Basin. The borehole is located to recover an expanded and complete succession to complement the legacy core from the Llanbedr (Mochras Farm) borehole drilled through 1967–1969 on the edge of the Cardigan Bay Basin, North Wales. The overall aim of the project is to construct an astronomically calibrated integrated timescale for the Early Jurassic and to provide insights into the operation of the Early Jurassic Earth system. Core of Quaternary age cover and Early Jurassic mudstone was obtained from two shallow partially cored geotechnical holes (Prees 2A to 32.2 m below surface (m b.s.) and Prees 2B to 37.0 m b.s.) together with Early Jurassic and Late Triassic mudstone from the principal hole, Prees 2C, which was cored from 32.92 to 651.32 m (corrected core depth scale). Core recovery was 99.7 % for Prees 2C. The ages of the recovered stratigraphy range from the Late Triassic (probably Rhaetian) to the Early Jurassic, Early Pliensbachian (Ibex Ammonoid Chronozone). All ammonoid chronozones have been identified for the drilled Early Jurassic strata. The full lithological succession comprises the Branscombe Mudstone and Blue Anchor formations of the Mercia Mudstone Group, the Westbury and Lilstock formations of the Penarth Group, and the Redcar Mudstone Formation of the Lias Group. A distinct interval of siltstone is recognized within the Late Sinemurian of the Redcar Mudstone Formation, and the name “Prees Siltstone Member” is proposed. Depositional environments range from playa lake in the Late Triassic to distal offshore marine in the Early Jurassic. Initial datasets compiled from the core include radiography, natural gamma ray, density, magnetic susceptibility, and X-ray fluorescence (XRF). A full suite of downhole logs was also run. Intervals of organic carbon enrichment occur in the Rhaetian (Late Triassic) Westbury Formation and in the earliest Hettangian and earliest Pliensbachian strata of the Redcar Mudstone Formation, where up to 4 % total organic carbon (TOC) is recorded. Other parts of the succession are generally organic-lean, containing less than 1 % TOC. Carbon-isotope values from bulk organic matter have also been determined, initially at a resolution of ∼ 1 m, and these provide the basis for detailed correlation between the Prees 2 succession and adjacent boreholes and Global Stratotype Section and Point (GSSP) outcrops. Multiple complementary studies are currently underway and preliminary results promise an astronomically calibrated biostratigraphy, magnetostratigraphy, and chemostratigraphy for the combined Prees and Mochras successions as well as insights into the dynamics of background processes and major palaeo-environmental changes.ICDPNatural Environment Research Council (NERC)German Research FoundationHungarian Scientific Research FundNational Science Centre, PolandPolish Geological Institut

Late Cenozoic bending of the Bolivian Andes: New paleomagnetic and kinematic constraints

New paleomagnetic measurements of essentially undeformed Late Cenozoic volcanic rocks in the Bolivian Andes, South America, constrain rigid body rotations about vertical axes during the last ∼13 Myr on both limbs of the Bolivian orocline in the Eastern Cordillera. Thermal and alternating field demagnetization was carried out on samples from 52 sites in three major volcanic complexes: (1) 13-2 Ma Los Frailes ignimbritic volcanics, outcropping at ∼19.5°S; (2) 9-5 Ma Morococala ignimbritic volcanics, outcropping at ∼18°S; and (3) 13-5 Ma shoshonitic to acidic lavas and intrusives, outcropping at ∼17.5°S. Well-defined magnetic components were isolated, which are interpreted to represent the Earth's magnetic field at the time of volcanic activity. The mean magnetic vector for site groupings suggests regional tectonic rotations about vertical axes, with respect to stable South America, of 10° ± 8 clockwise for the 13-2 Ma Los Frailes volcanic complex (8° ± 9° clockwise for only the Miocene (13-5 Ma) Los Frailes volcanics), and 1° ± 18° anticlockwise for the combined 13-5 Ma Morococala and Eucalyptus volcanic complexes. These data are consistent with observed shortening gradients on the eastern margin of the Bolivian Andes, in the sub-Andean zone, suggesting rotation and shortening are synchronous. A joint inversion for both tectonic rotation and the amount of shortening, assuming a linear variation in the amount of rotation along the length of the southern limb of the Bolivian orocline, shows that rotation of the Eastern Cordillera in the last 10-15 Myr, relative to stable South America, varies from zero at the oroclinal hinge, at ∼18°S, to a maximum of ∼13.5° clockwise at ∼22°S, decreasing to zero, south of 23°S, with an average rotation in the range 5° to 10° clockwise. Concomitant with this, shortening in the sub-Andean zone decreases from a maximum of ∼86 km at the oroclinal hinge, to ∼47 Ian at 22°S, and then ∼33 km at 23°S. The lack of evidence for large-scale internal faulting in the Eastern Cordillera since ∼9 Ma suggests either bending of the Eastern Cordillera was accommodated by more distributed small-scale faulting or that relative rotation here mainly occurred prior to ∼9 Ma. The small average rotation of the Eastern Cordillera, on the southern limb of the orocline, is consistent with only very small rotation (<10°) of the forearc region in northern Chile during the last ∼20 Myr. Rotation of the northern limb is less well constrained, but it is also Rely to be small (<5°) and anticlockwise. Copyright 2007 by the American Geophysical Union

OROCLINAL BENDING IN THE CALEDONIDES OF WESTERN IRELAND

New palaeomagnetic data from the Caledonides of western Ireland indicate that the Silurian rocks of South Mayo underwent oroclinal bending, following folding, in Siluro-Devonian time. Bending was accommodated on faults cutting the Silurian sequence, and was driven by strike slip motion across the Antrim-Galway Line, a recently recognized major curvilinear lineament. The Silurian rocks in the east of the region suffered up to 30° clockwise rotation, increasing towards the west to approximately 70°. This implies that the underlying Dalradian rocks of the Connemara Massif to the south must also have undergone clockwise rotation in late Silurian/early Devonian time. This is consistent with published paleomagnetic data from the Connemara Gabbro and accounts for the swing in strike of the Caledonian orogen in this part of western Ireland. -from Author

Ordovician paleogeography and the evolution of the lapetus ocean

Paleomagnetic data from northern Appalachian terranes identify several arcs within the lapetus ocean in the Early to Middle Ordovician, including a peri-Laurentian arc at ∼10°-20°S, a peri-Avalonian arc at ∼50°-60°S, and an intra-oceanic arc (called the Exploits arc) at ∼30°S. The peri-Avalonian and Exploits arcs are characterized by Arenigian to Llanvirnian Celtic fauna that are distinct from similarly aged Toquima-Table Head fauna of the Laurentian margin, and peri-Laurentian arc. The Precorclillera terrane of Argentina is also characterized by an increasing proportion of Celtic fauna from Arenig to Llanvirn time, which implies (1) that it was in reproductive communication with the peri-Avalonian and Exploits arcs, and (2) that it must have been separate from Laurenfia and the peri-Laurentian arc well before it collided with Gondwana. Collectively, the paleomagnetic and faunal data require an open Ordovician ocean adjacent to the Appalachian margin and argue against a Taconic-Famatinian collision between North and South America