Robust quantum-network memory using decoherence-protected subspaces of nuclear spins

The realization of a network of quantum registers is an outstanding challenge in quantum science and technology. We experimentally investigate a network node that consists of a single nitrogen-vacancy (NV) center electronic spin hyperfine-coupled to nearby nuclear spins. We demonstrate individual control and readout of five nuclear spin qubits within one node. We then characterize the storage of quantum superpositions in individual nuclear spins under repeated application of a probabilistic optical inter-node entangling protocol. We find that the storage fidelity is limited by dephasing during the electronic spin reset after failed attempts. By encoding quantum states into a decoherence-protected subspace of two nuclear spins we show that quantum coherence can be maintained for over 1000 repetitions of the remote entangling protocol. These results and insights pave the way towards remote entanglement purification and the realisation of a quantum repeater using NV center quantum network nodes

Data availibility for the fisheries impact assessment of the FIMPAS project

The project Fisheries Measures in Protected Areas (FIMPAS) aims to introduce fisheries measures in the marine Natura 2000 sites within the Exclusive Economic Zone of the Dutch part of the North Sea by the end of 2011. The FIMPAS project covers three such areas, the Dogger Bank and the Cleaver Bank (both to be designated for protection under the Habitats Directive) and the Frisian Front (to be designated for protection under the Birds Directive). These sites are beyond the Dutch 12 nm zone and several EU Member States fish within these areas. Therefore fisheries measures must be implemented through the Common Fisheries Policy. These marine protected areas, as well as the potential fisheries measures, are a consequence of the implementation of the European Birds and Habitats Directives and will be proposed to the European Commission by the Dutch government. The Dutch Ministry for Agriculture, Nature and Food Quality (LNV), together with Dutch environmental NGOs and the Dutch fishing industry, are cooperating within the FIMPAS project to develop the necessary fisheries measures to achieve the conservation objectives for the Dutch Natura 2000 sites of the North Sea. LNV has asked the International Council for the Exploration of the Sea (ICES) to organize the necessary scientific processes and give advice on the desired fisheries measures involving the relevant stakeholders in this process

Bird communities of contrasting semi-natural habitats of Lac bay, Bonaire, during the fall migration season, 2011

The mangrove and seagrass lagoon of Lac Bay on Bonaire covers an area of roughly 700 ha. It is home to endangered green sea turtles, Chelonia mydas, and the Caribbean queen conch, Strombus gigas, and is a roosting and breeding area for several birds. Based on its nature values this 7 km2 bay has been designated as a legally protected Ramsar site. The area falls under the management responsibility of the National Parks Foundation of Bonaire

The effects of subtidal mussel seed fisheries in the Dutch Wadden Sea on sediment composition

In this report, the effect of seed mussel fishery activities on sediment composition is analysed. The hypothesis is that dredging for mussels brings fine silt in suspension. Tidal currents move silt away from the fishing site and a more course sediment is left behind. For PRODUS experimental plots of each 400 x 200 m have been marked out on sites were natural mussel seed occurred: on one half of the plots fishing was prohibited and on the other half fishing was allowed. Per plot 12 boxcorer samples were taken from which sediment samples were collected before and after fishing. Most plots have also been sampled later during the research, to test for increasing similarity of fished and control sites over time

A Migratory Divide Among Red-Necked Phalaropes in the Western Palearctic Reveals Contrasting Migration and Wintering Movement Strategies

Non-breeding movement strategies of migratory birds may be expected to be flexibly adjusted to the distribution and quality of habitat, but only few studies compare movement strategies between populations using distinct migration routes and wintering areas. In thisour study, individual movement strategies of Rred-necked pPhalaropes Phalaropus lobatus, a long-distance migratory wader using saline waters in the non-breeding period, were studied using light-level geolocators. Results revealed the existence of two populations with distinct migration routes and wintering areas: one breeding in the north-eastern North Atlantic and migrating ca. 10,000 km oversea to the tropical eastern Pacific Ocean and the other breeding in Fennoscandia and Russia migrating ca. 6,000 km – largely over land – to the Arabian Sea (Indian Ocean). In line with our expectations, the transoceanic migration between the North Atlantic and the Pacific was associated with proportionately longer wings, a more even spread of stopovers in autumn and a higher migration speed in spring compared to the migration between Fennoscandian-Russian breeding grounds and the Arabian Sea. In the wintering period, birds wintering in the Pacific were stationaryresided in roughly a singlethe same area, whereas individuals wintering in the Arabian Sea showed individually consistent movementsd extensively between different areas, reflecting differences in spatio-temporal variation in primary productivity between the two wintering areas. Our study is unique in showing how habitat distribution shapes movement strategies over the entire non-breeding period within a species.Peer reviewe

Tectonic denudation and topographic development in the Spanish Sierra Nevada

The denudation history of the rapidly uplifting western part of the Spanish Sierra Nevada was assessed using apatite fission track (AFT) ages and 10Be analyses of bedrock and fluvial sediments. Major contrasts in the denudation history are recorded within the 27 km2 Río Torrente catchment. Upland areas are characterized by low-relief, low slope angles, and locally the preservation of shallow marine sediments, which have experienced <200 m of erosion in the last 9 Myr. However, AFT age determinations from samples collected close to the marine sediments imply >2 km of denudation since circa 4 Ma. The minimum denudation rates of 0.4 mm yr−1 derived from AFT also contrast with the slow medium-term (104 years) erosion rates (0.044 ± 0.015 mm yr−1) estimated from 10Be measurements at high elevations. The local medium-long-term contrasts in denudation rates within the high Sierra Nevada indicate that much of the unroofing occurs by tectonic denudation on flat-lying detachments. In lower elevation parts of the catchment, rapid river incision coupled to rock uplift has produced ∼1.6 km of relief, implying that the rivers and adjacent hillslopes close to the edge of the orogen are sensitive to normal-fault-driven changes in base level. However, these changes are not transmitted into the low-relief slowly eroding upland areas. Thus the core of the mountain range continues to increase in elevation until the limits of crustal strength are reached and denudation is initiated along planes of structural weakness. We propose that this form of tectonic denudation provides an effective limit to relief in young orogens

The chlorite proximitor: A new tool for detecting porphyry ore deposits

publisher: Elsevier articletitle: The chlorite proximitor: A new tool for detecting porphyry ore deposits journaltitle: Journal of Geochemical Exploration articlelink: http://dx.doi.org/10.1016/j.gexplo.2015.01.005 content_type: article copyright: Crown copyright © 2015 Published by Elsevier B.V.Copyright © 2016 Elsevier B.V. or its licensors or contributors. ScienceDirect ® is a registered trademark of Elsevier B.V. [Creative Commons License 4.0]. The attached file is the published version of the article