2,242 research outputs found
Design of Marine Protected Areas on high seas and territorial waters of rockall bank
Fisheries closures are rapidly being developed to protect vulnerable marine ecosystems worldwide. Satellite monitoring of fishing vessel activity indicates that these closures can work effectively with good compliance by international fleets even in remote areas. Here we summarise how remote fisheries closures were designed to protect Lophelia pertusa habitat in a region of the NE Atlantic that straddles the EU fishing zone and the high seas. We show how scientific records, fishers' knowledge and surveillance data on fishing activity can be combined to provide a powerful tool for the design of Marine Protected Areas. © Inter-Research 2009
Magnetism and half-metallicity at the O surfaces of ceramic oxides
The occurence of spin-polarization at ZrO, AlO and MgO
surfaces is proved by means of \textit{ab-initio} calculations within the
density functional theory. Large spin moments, as high as 1.56 , develop
at O-ended polar terminations, transforming the non-magnetic insulator into a
half-metal. The magnetic moments mainly reside in the surface oxygen atoms and
their origin is related to the existence of holes of well-defined spin
polarization at the valence band of the ionic oxide. The direct relation
between magnetization and local loss of donor charge makes possible to extend
the magnetization mechanism beyond surface properties
Salicylaldehyde hydrazones: buttressing of outer sphere hydrogen-bonding and copper-extraction properties
Salicylaldehyde hydrazones are weaker copper extractants than their oxime derivatives, which are used in hydrometallurgical processes to recover ~20 % of the world’s copper. Their strength, based on the extraction equilibrium constant Ke, can be increased by nearly three orders of magnitude by incorporating electron-withdrawing or hydrogen-bond acceptor groups (X) ortho to the phenolic OH group of the salicylaldehyde unit. Density functional theory calculations suggest that the effects of the 3-X substituents arise from a combination of their influence on the acidity of the phenol in the pH-dependent equilibrium, Cu2+ + 2Lorg ⇌ [Cu(L–H)2]org + 2H+, and on their ability to ‘buttress’ interligand hydrogen bonding by interacting with the hydrazone N–H donor group. X-ray crystal structure determination and computed structures indicate that in both the solid state and the gas phase, coordinated hydrazone groups are less planar than coordinated oximes and this has an adverse effect on intramolecular hydrogen-bond formation to the neighbouring phenolate oxygen atoms
Value co-creation in the delivery of outcome-based contracts for business-to-business service
Working paperThis study introduces the concept of outcome-based contracting (OBC) as the mechanism for firms to focus on delivering value-in-use, and as the driver for value co-creation as the firm would need to jointly deliver outcomes with the customer. The paper analyses two OBC-type contracts between the UK Ministry of Defence and two of its industrial partners. We find that in delivering to outcomes and achieving value-in-use, the state-dependent nature of value in usage „pushes back‟ into the organization, requiring the firm to re-evaluate the way they are structured to receive changes from customer state-dependencies so as to deliver a better service. Our analysis presents seven generic attributes of value co-creation (AVCs) essential for the capability to deliver value-in-use. These are behavioral alignment, process alignment, congruence in customer expectations, congruence in firm expectations, empowerment and perceived control, behavioral transformation, and complementary competencies. The attributes discovered through qualitative data were matched with previous academic literature and operationalized and a measurement instrument was developed. The instrument was then validated by performing an exploratory and second order confirmatory factor analysis.This research was made possible through the joint funding of the Engineering & Physical Science Research Council (UK) and BAE Systems on the Support Service Solutions: Strategy & Transition (S4T) project consortium led by the University of Cambridge. The authors gratefully acknowledge the staff of BAE Systems and MBDA as well as members of the ADAPT IPT, 16th Regiment, ATTAC IPT, MoD and the RAF who have all contributed substantially towards this research
Kelvin-Helmholtz instabilities in Smoothed Particle Hydrodynamics
In this paper we investigate whether Smoothed Particle Hydrodynamics (SPH),
equipped with artificial conductivity, is able to capture the physics of
density/energy discontinuities in the case of the so-called shearing layers
test, a test for examining Kelvin-Helmholtz (KH) instabilities. We can trace
back each failure of SPH to show KH rolls to two causes: i) shock waves
travelling in the simulation box and ii) particle clumping, or more generally,
particle noise. The probable cause of shock waves is the Local Mixing
Instability (LMI), previously identified in the literature. Particle noise on
the other hand is a problem because it introduces a large error in the SPH
momentum equation.
We also investigate the role of artificial conductivity (AC). Including AC is
necessary for the long-term behavior of the simulation (e.g. to get
KH rolls). In sensitive hydrodynamical simulations great care
is however needed in selecting the AC signal velocity, with the default
formulation leading to too much energy diffusion. We present new signal
velocities that lead to less diffusion.
The effects of the shock waves and of particle disorder become less important
as the time-scale of the physical problem (for the shearing layers problem:
lower density contrast and higher Mach numbers) decreases. At the resolution of
current galaxy formation simulations mixing is probably not important. However,
mixing could become crucial for next-generation simulations.Comment: 16 pages, 23 figures, accepted for publication in MNRA
Follow-up monitoring in a cat with leishmaniosis and coinfections with Hepatozoon felis and ‘Candidatus Mycoplasma haemominutum’
Case summary
A 6-year-old female neutered domestic shorthair cat from Cyprus was presented with multiple ulcerated skin nodules. Cytology and histopathology of the lesions revealed granulomatous dermatitis with intracytoplasmic organisms, consistent with amastigotes of Leishmania species. Biochemistry identified a mild hyperproteinaemia. Blood extraction and PCR detected Leishmania species, Hepatozoon species and ‘Candidatus Mycoplasma haemominutum’ (CMhm) DNA. Subsequent sequencing identified Hepatozoon felis. Additionally, the rRNA internal transcribed spacer 1 locus of Leishmania infantum was partially sequenced and phylogeny showed it to cluster with species derived from dogs in Italy and Uzbekistan, and a human in France. Allopurinol treatment was administered for 6 months. Clinical signs resolved in the second month of treatment with no deterioration 8 months post-treatment cessation. Quantitative PCR and ELISA were used to monitor L infantum blood DNA and antibody levels. The cat had high L infantum DNA levels pretreatment that gradually declined during treatment but increased 8 months post-treatment cessation. Similarly, ELISA revealed high levels of antibodies pretreatment, which gradually declined during treatment and increased slightly 8 months post-treatment cessation. The cat remained PCR positive for CMhm and Hepatozoon species throughout the study. There was no clinical evidence of relapse 24 months post-treatment.
Relevance and novel information
To our knowledge, this is the first clinical report of a cat with leishmaniosis with H felis and CMhm coinfections. The high L infantum DNA levels post-treatment cessation might indicate that although the lesions had resolved, prolonged or an alternative treatment could have been considere
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