Scalability of a packet-switched WDM MAN with support for optical multicasting

This paper addresses the scalability (in terms of the number of nodes) of a packetswitched WDM all-optical bi-directional ring for metropolitan area networks. The nodes enable adding/dropping packets to/from all WDM channels on the ring. The nodes are optically transparent to data packets that bypass them. At a linespeed of 2.5 Gbps using directly modulated DFB lasers separated by 400 GHz, EDFAs to compensate for optical power loss and Phasars for wavelength multiplexing/demultiplexing it has been experimentally observed that a single ring can support upto 8 transparent nodes

A Metropolitan Optical Network with Support for Multicasting in the Optical Domain

We present the FLAMINGO1 network architecture, an all-optical wavelength-and-timeslotted Metropolitan Optical Network based on a multiple-ring topology. A couple of important aspects of this architecture include all-optical packet switching at intermediate nodes on a ring and the ability to put IP packets directly over WDM channels. The rings of the network are interconnected with intelligent bridges, architecture of which is presented. The network also enables all-optical multicasting at intermediate nodes, the architecture of which is also presented. Power budget calculations have also been dealt with and discussed in detail

Scalability of an All-optical Multiwavelength Slottedring Metropolitan Area Network

In this paper simulation results of the bit error rate (BER) performance of an all-optical multiwavelength slotted-ring metropolitan area network (MAN) are presented. The simulation results provide insight into the signal-to-noise ratio (SNR) degradation as the optical ring is scaled up in terms of the number of access points on it. The results also enable us to understand the effect of inband crosstalk (generated by the adding and dropping of packets at the optically transparent access points) on the bit error rate. A few techniques to improve the BER performance, resulting from inband crosstalk, are proposed

Contrast enhancement by differently sized paramagnetic MRI contrast agents in mice with two phenotypes of atherosclerotic plaque

Interest in the use of contrast-enhanced MRI to enable in vivo specific characterization of atherosclerotic plaques is increasing. In this study the intrinsic ability of three differently sized gadolinium-based contrast agents to permeate different mouse plaque phenotypes was evaluated with MRI. A tapered cast was implanted around the right carotid artery of apoE-/- mice to induce two different plaque phenotypes: a thin cap fibroatheroma (TCFA) and a non-TCFA lesion. Both plaques were allowed to develop over 6 and 9 weeks, leading to an intermediate and advanced lesion, respectively. Signal enhancement in the carotid artery wall, following intravenous injection of Gd-HP-DO3A as well as paramagnetic micelles and liposomes was evaluated. In vivo T1-weighted MRI plaque enhancement characteristics were complemented by fluorescence microscopy and correlated to lesion phenotype. The two smallest contrast agents, i.e. Gd-HP-DO3A and micelles, were found to enhance contrast in T1-weighted MR images of all investigated plaque phenotypes. Maximum contrast enhancement ranged between 53 and 70% at 6¿min after injection of Gd-HP-DO3A with highest enhancement and longest retention in the non-TCFA lesion. Twenty-four hours after injection of micelles maximum contrast enhancement ranged between 24 and 35% in all plaque phenotypes. Administration of the larger liposomes did not cause significant contrast enhancement in the atherosclerotic plaques. Confocal fluorescence microscopy confirmed the MRI-based differences in plaque permeation between micelles and liposomes. Plaque permeation of contrast agents was strongly dependent on size. Our results implicate that, when equipped with targeting ligands, liposomes are most suitable for the imaging of plaque-associated endothelial markers due to low background enhancement, whereas micelles, which accumulate extravascularly on a long timescale, are suited for imaging of less abundant markers inside plaques. Low molecular weight compounds may be employed for target-specific imaging of highly abundant extravascular plaque-associated target

Broadening the scope of live-in migrant care research: How care networks shape the experience of precarious work

Live-in migrant care work is increasing across welfare states. In the context of ageing populations and changing healthcare systems, live-in care enables ageing in place without overburdening family caregivers. However, research has shown that live-in care often puts migrant care workers and their recipients in precarious positions. While the outcome of precarious work has gained attention, it is not self-evident. Based on interviews with migrant care workers in the Netherlands, as well as formal and informal caregivers, and the staff of intermediary organisations, this study shows that besides client conditions, the interactions of actors in the care network shape the circumstances and experience of migrant live-in care work. The findings suggest that managing the care networks to which migrant care workers belong makes it possible to mitigate the associated precariousness

Disruptive life event or reflexive instrument? On the regulation of hospital mergers from a quality of care perspective

Purpose – Despite the continuation of hospital mergers in many western countries, it is uncertain if and how hospital mergers impact the quality of care. This poses challenges for the regulation of mergers. The purpose of this paper is to understand: how regulators and hospitals frame the impact of merging on the quality and safety of care and how hospital mergers might be regulated, given their uncertain impact on quality and safety of care. Design/methodology/approach –This paper studies the regulation of hospital mergers in The Netherlands. In a qualitative study design, it draws on 30 semi-structured interviews with inspectors from the Dutch Health and Youth Care Inspectorate (Inspectorate) and respondents from three hospitals that merged between 2013 and 2015. This paper draws from literature on process-based regulation to understand how regulators can monitor hospital mergers. Findings – This paper finds that inspectors and hospital respondents frame the process of merging as potentially disruptive to daily care practices. While inspectors emphasise the dangers of merging, hospital respondents report how merging stimulated them to reflect on their care practices and how it afforded learning between hospitals. Although the Inspectorate considers mergers a risk to quality of care, their regulatory practices are hesitant. Originality/value – This qualitative study sheds light on how merging might affect key hospital processes and daily care practices. It offers opportunities for the regulation of hospital mergers that acknowledges rather than aims to dispel the uncertain and potentially ambiguous impact of mergers on quality and safety of car

A global map to aid the identification and screening of critical habitat for marine industries

Marine industries face a number of risks that necessitate careful analysis prior to making decisions on the siting of operations and facilities. An important emerging regulatory framework on environmental sustainability for business operations is the International Finance Corporation’s Performance Standard 6 (IFC PS6). Within PS6, identification of biodiversity significance is articulated through the concept of “Critical Habitat”, a definition developed by the IFC and detailed through criteria aligned with those that support internationally accepted biodiversity designations. No publicly available tools have been developed in either the marine or terrestrial realm to assess the likelihood of sites or operations being located within PS6-defined Critical Habitat. This paper presents a starting point towards filling this gap in the form of a preliminary global map that classifies more than 13 million km2 of marine and coastal areas of importance for biodiversity (protected areas, Key Biodiversity Areas [KBA], sea turtle nesting sites, cold- and warm-water corals, seamounts, seagrass beds, mangroves, saltmarshes, hydrothermal vents and cold seeps) based on their overlap with Critical Habitat criteria, as defined by IFC. In total, 5798×103 km2 (1.6%) of the analysis area (global ocean plus coastal land strip) were classed as Likely Critical Habitat, and 7526×103 km2 (2.1%) as Potential Critical Habitat; the remainder (96.3%) were Unclassified. The latter was primarily due to the paucity of biodiversity data in marine areas beyond national jurisdiction and/or in deep waters, and the comparatively fewer protected areas and KBAs in these regions. Globally, protected areas constituted 65.9% of the combined Likely and Potential Critical Habitat extent, and KBAs 29.3%, not accounting for the overlap between these two features. Relative Critical Habitat extent in Exclusive Economic Zones varied dramatically between countries. This work is likely to be of particular use for industries operating in the marine and coastal realms as an early screening aid prior to in situ Critical Habitat assessment; to financial institutions making investment decisions; and to those wishing to implement good practice policies relevant to biodiversity management. Supplementary material (available online) includes other global datasets considered, documentation and justification of biodiversity feature classification, detail of IFC PS6 criteria/scenarios, and coverage calculations

Fixing extraction through conservation : on crises, fixes and the production of shared value and threat

We are currently witnessing a global trend of intensifying and deepening relationships between extractive companies and biodiversity conservation organisations that warrants closer scrutiny. Although existing literature has established that these two sectors often share the same space and rely on similar logics, it is increasingly common to find biodiversity conservation being carried out through partnerships between extractive and conservation actors. In this article, we explore what this cooperation achieves for both sectors. Using illustrative examples of extractive-conservation collaboration across sub-Saharan Africa, we argue that new entanglements between extractive and conservation actors are motivated by multiple purposes. First, partnering with conservation actors serves as a spatial and socio-ecological fix for extractive companies in response to multiple crises that threaten the sector's productivity. Second, new forms of collaboration between extractive and conservation actors create pathways for both sectors to produce new value from nature. For the extractive sector, creating new value from nature works as a further fix to capitalist crises whereas, for the conservation sector, producing value through nature amounts to new opportunities for capital accumulation. Importantly, working together to produce shared value from nature within and beyond extractive concessions secures both sectors' control over the means of production. Theoretically, our analysis links literature on value in capitalist nature with that on spatial and socio-ecological fixes

Answering biological questions: querying a systems biology database for nutrigenomics

The requirement of systems biology for connecting different levels of biological research leads directly to a need for integrating vast amounts of diverse information in general and of omics data in particular. The nutritional phenotype database addresses this challenge for nutrigenomics. A particularly urgent objective in coping with the data avalanche is making biologically meaningful information accessible to the researcher. This contribution describes how we intend to meet this objective with the nutritional phenotype database. We outline relevant parts of the system architecture, describe the kinds of data managed by it, and show how the system can support retrieval of biologically meaningful information by means of ontologies, full-text queries, and structured queries. Our contribution points out critical points, describes several technical hurdles. It demonstrates how pathway analysis can improve queries and comparisons for nutrition studies. Finally, three directions for future research are given

A global map of saltmarshes

Background Saltmarshes are extremely valuable but often overlooked ecosystems, contributing to livelihoods locally and globally through the associated ecosystem services they provide, including fish production, carbon storage and coastal protection. Despite their importance, knowledge of the current spatial distribution (occurrence and extent) of saltmarshes is incomplete. In light of increasing anthropogenic and environmental pressures on coastal ecosystems, global data on the occurrence and extent of saltmarshes are needed to draw attention to these critical ecosystems and to the benefits they generate for people. Such data can support resource management, strengthen decision-making and facilitate tracking of progress towards global conservation targets set by multilateral environmental agreements, such as the Aichi Biodiversity Targets of the United Nations' (UN's) Strategic Plan for Biodiversity 2011-2020, the Sustainable Development Goals of the UN's 2030 Agenda for Sustainable Development and the Ramsar Convention. New information Here, we present the most complete dataset on saltmarsh occurrence and extent at the global scale. This dataset collates 350,985 individual occurrences of saltmarshes and presents the first global estimate of their known extent. The dataset captures locational and contextual data for saltmarsh in 99 countries worldwide. A total of 5,495,089 hectares of mapped saltmarsh across 43 countries and territories are represented in a Geographic Information Systems polygon shapefile. This estimate is at the relatively low end of previous estimates (2.2-40 Mha), however, we took the conservative approach in the mapping exercise and there are notable areas in Canada, Northern Russia, South America and Africa where saltmarshes are known to occur that require additional spatial data. Nevertheless, the most extensive saltmarsh worldwide are found outside the tropics, notably including the low-lying, ice-free coasts, bays and estuaries of the North Atlantic which are well represented in our global polygon dataset. Therefore, despite the gaps, we believe that, while incomplete, our global polygon data cover many of the important areas in Europe, the USA and Australia