A late Pleistocene long pollen record from Lake Urmia, NW Iran

A palynological study based on two 100-m long cores from Lake Urmia in northwestern Iran provides a vegetation record spanning 200 ka, the longest pollen record for the continental interior of the Near East. During both penultimate and last glaciations, a steppe of Artemisia and Poaceae dominated the upland vegetation with a high proportion of Chenopodiaceae in both upland and lowland saline ecosystems. While Juniperus and deciduous Quercus trees were extremely rare and restricted to some refugia, Hippophaë rhamnoides constituted an important phanerophyte, particularly during the upper last glacial sediments. A pronounced expansion in Ephedra shrub-steppe occurred at the end of the penultimate late-glacial period but was followed by extreme aridity that favoured an Artemisia steppe. Very high lake levels, registered by both pollen and sedimentary markers, occurred during the middle of the last glaciation and upper part of the penultimate glaciation. The late-glacial to early Holocene transition is represented by a succession of Hippophaë, Ephedra, Betula, Pistacia and finally Juniperus and Quercus. The last interglacial period (Eemian), slightly warmer and moister than the Holocene, was followed by two interstadial phases similar in pattern to those recorded in the marine isotope record and southern European pollen sequences

SA-NET.V2: REAL-TIME VEHICLE DETECTION FROM OBLIQUE UAV IMAGES WITH USE OF UNCERTAINTY ESTIMATION IN DEEP META-LEARNING

In recent years, unmanned aerial vehicle (UAV) imaging is a suitable solution for real-time monitoring different vehicles on the urban scale. Real-time vehicle detection with the use of uncertainty estimation in deep meta-learning for the portable platforms (e.g., UAV) potentially improves video understanding in real-world applications with a small training dataset, while many vehicle monitoring approaches appear to understand single-time detection with a big training dataset. The purpose of real-time vehicle detection from oblique UAV images is to locate the vehicle on the time series UAV images by using semantic segmentation. Real-time vehicle detection is more difficult due to the variety of depth and scale vehicles in oblique view UAV images. Motivated by these facts, in this manuscript, we consider the problem of real-time vehicle detection for oblique UAV images based on a small training dataset and deep meta-learning. The proposed architecture, called SA-Net.v2, is a developed method based on the SA-CNN for real-time vehicle detection by reformulating the squeeze-and-attention mechanism. The SA-Net.v2 is composed of two components, including the squeeze-and-attention function that extracts the high-level feature based on a small training dataset, and the gated CNN. For the real-time vehicle detection scenario, we test our model on the UAVid dataset. UAVid is a time series oblique UAV images dataset consisting of 30 video sequences. We examine the proposed method's applicability for stand real-time vehicle detection in urban environments using time series UAV images. The experiments show that the SA-Net.v2 achieves promising performance in time series oblique UAV images

Lingulodinium machaerophorum expansion over the last centuries in the Caspian Sea reflects global warming

This article is made available through the Brunel Open Access Publishing Fund. Copyright @ Author(s) 2012. This work is distributed under the Creative Commons Attribution 3.0 License.We analysed dinoflagellate cyst assemblages in four short sediment cores, two of them dated by radionuclides, taken in the south basin of the Caspian Sea. The interpretation of the four sequences is supported by a collection of 27 lagoonal or marine surface sediment samples. A sharp increase in the biomass of the dinocyst occurs after 1967, especially owing to Lingulodinium machaerophorum. Considering nine other cores covering parts or the whole of Holocene, this species started to develop in the Caspian Sea only during the last three millennia. By analysing instrumental data and collating existing reconstructions of sea level changes over the last few millennia, we show that the main forcing of the increase of L. machaerophorum percentages and of the recent dinocyst abundance is global climate change, especially sea surface temperature increase. Sea level fluctuations likely have a minor impact. We argue that the Caspian Sea has entered the Anthropocene

A one femtojoule athermal silicon modulator

Silicon photonics has emerged as the leading candidate for implementing ultralow power wavelength division multiplexed communication networks in high-performance computers, yet current components (lasers, modulators, filters, and detectors) consume too much power for the femtojouleclass links that will ultimately be required. Here, we propose, demonstrate, and characterize the first modulator to achieve simultaneous high-speed (25-Gb/s), low voltage (0.5VPP) and efficient 1-fJ/bit error-free operation while maintaining athermal operation. Both the low energy and athermal operation were enabled by a record free-carrier accumulation/depletion response obtained in a vertical p-n junction device that at 250-pm/V (30-GHz/V) is up to ten times larger than prior demonstrations. Over a 7.5{\deg}C temperature range, the massive electro-optic response was used to compensate for thermal drift without increasing energy consumption and over a 10{\deg}C temperature range, increasing energy consumption by only 2-fJ/bit. The results represent a new paradigm in modulator development, one where thermal compensation is achieved electro-optically.Comment: 23 pages, 5 figure

Late Little Ice Age palaeoenvironmental records from the Anzali and Amirkola Lagoons (south Caspian Sea): Vegetation and sea level changes

This is a postprint version of the article. The official published article can be found from the link below - Copyright @ 2011 Elsevier Ltd.Two internationally important Ramsar lagoons on the south coast of the Caspian Sea (CS) have been studied by palynology on short sediment cores for palaeoenvironmental and palaeoclimatic investigations. The sites lie within a small area of very high precipitation in a region that is otherwise dry. Vegetation surveys and geomorphological investigations have been used to provide a background to a multidisciplinary interpretation of the two sequences covering the last four centuries. In the small lagoon of Amirkola, the dense alder forested wetland has been briefly disturbed by fire, followed by the expansion of rice paddies from AD1720 to 1800. On the contrary, the terrestrial vegetation reflecting the diversity of the Hyrcanian vegetation around the lagoon of Anzali remained fairly complacent over time. The dinocyst and non-pollen palynomorph assemblages, revealing changes that have occurred in water salinity and water levels, indicate a high stand during the late Little Ice Age (LIA), from AD < 1620 to 1800–1830. In Amirkola, the lagoon spit remained intact over time, whereas in Anzali it broke into barrier islands during the late LIA, which merged into a spit during the subsequent sea level drop. A high population density and infrastructure prevented renewed breaking up of the spit when sea level reached its maximum (AD1995). Similar to other sites in the region around the southern CS, these two lagoonal investigations indicate that the LIA had a higher sea level as a result of more rainfall in the drainage basin of the CS.The coring and the sedimentological analyses were funded by the Iranian National Institute for Oceanography in the framework of a research project entitled “Investigation of the Holocene sediment along the Iranian coast of Caspian Sea: central Guilan”. The radiocarbon date of core HCGL02 was funded by V. Andrieu (Europôle Méditerranéen de l'Arbois, France) and that of core HCGA04 by Brunel University

Optical symmetries and anisotropic transport in high-Tc superconductors

A simple symmetry analysis of in-plane and out-of-plane transport in a family of high temperature superconductors is presented. It is shown that generalized scaling relations exist between the low frequency electronic Raman response and the low frequency in-plane and out-of-plane conductivities in both the normal and superconducting states of the cuprates. Specifically, for both the normal and superconducting state, the temperature dependence of the low frequency $B_{1g}$ Raman slope scales with the $c-$axis conductivity, while the $B_{2g}$ Raman slope scales with the in-plane conductivity. Comparison with experiments in the normal state of Bi-2212 and Y-123 imply that the nodal transport is largely doping independent and metallic, while transport near the BZ axes is governed by a quantum critical point near doping $p\sim 0.22$ holes per CuO$_{2}$ plaquette. Important differences for La-214 are discussed. It is also shown that the $c-$ axis conductivity rise for $T\ll T_{c}$ is a consequence of partial conservation of in-plane momentum for out-of-plane transport.Comment: 16 pages, 8 Figures (3 pages added, new discussion on pseudogap and charge ordering in La214