6,698 research outputs found

    How should fracking research be funded?

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    The use of hydraulic fracturing (‘fracking’) to extract oil or gas from shales is a subject of controversy. There are many scientific questions about the risks associated with the technique, and much research remains to be done. ReFINE (Researching Fracking In Europe) is a research consortium led by Newcastle University and Durham University in the UK, focusing on the environmental impacts of shale gas and oil exploitation using fracking methods. The project was established to answer questions raised by members of the public across Europe on the risks of fracking. It aims to inform the debate surrounding fracking by undertaking scientific research, which will be peer-reviewed and openly accessible. This case study discusses the structure of ReFINE and the issues associated with using funding from oil and gas companies to support the research

    Star Formation in the Circumnuclear Environment of NGC1068

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    We present near-infrared emission line images of the circumnuclear ring in NGC1068. We have measured the Br_gamma fluxes in a number of star forming complexes and derived extinctions for each of these by comparison with H_alpha. We investigate the star forming histories of these regions and find that a short burst of star formation occured co-evally throughout the ring within the last 30-40 Myr, and perhaps as recently as 4-7 Myr ago. The 1-0 S(1) flux and S(1)/Br_gamma ratios indicate that as well as fluorescence, shock excited H_2 emission contributes to the total flux. There is excess H_2 flux to the North-West where the ionisation cone crosses the ring, and we have shown it is possible that the non-stellar continuum from the Seyfert nucleus which produces the high excitation lines could also be causing fluorescence at the edges of molecular clouds in the ring. The nuclear 1-0 S(1) is more extended than previously realised but only along the bar's major axis, and we consider mechanisms for its excitation.Comment: 10 pages, 4 figures, LaTeX (mn.sty & psfig.sty). Accepted for publication in MNRA

    Rapid Detection of Leishmania infantum Infection in Dogs: Comparative Study Using an Immunochromatographic Dipstick Test, Enzyme-Linked Immunosorbent Assay, and PCR

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    Current zoonotic visceral leishmaniasis (ZVL) control programs in Brazil include the culling of Leishmania infantum-infected reservoir dogs, a strategy that has failed to prevent a rise of canine and human ZVL cases over the past decade. One of the main reasons this strategy has failed is because of a long delay between sample collection, sample analysis, and control implementation. A rapid, sensitive, and specific diagnostic tool would be highly desirable, because it would allow control interventions to be implemented in situ. We compared an immunochromatographic dipstick test to enzyme-linked immunosorbent assay (ELISA) and PCR for detecting L. infantum infections in dogs from an area of ZVL endemicity in Brazil. The dipstick test was shown to have 61 to 75% specificity and 72 to 77% sensitivity, compared to 100% specificity for both ELISA and PCR and 71 to 88% and 51 to 64% sensitivity for ELISA and PCR, respectively. Of the field samples tested, 92 of 175 (53%), 65 of 175 (37%), and 47 of 175 (27%) were positive by dipstick, ELISA, and PCR, respectively. The positive and negative predictive values for the tested dipstick were 58 to 77% and 75%, respectively. Efforts should be made to develop a more specific dipstick test for diagnosis of leishmaniasis, because they may ultimately prove more cost-effective than currently used diagnostic tests when used in mass-screening surveys

    The flow generated in a continuously stratified rotating fluid by the differential rotation of a plane horizontal disc

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    Results are presented from a modelling investigation into the response of a rotating, linearly stratified fluid to local forcing induced by a differentially rotating smooth, horizontal disc. Attention was directed at cases in which the disc forcing is relatively strong, with Rossby number ε = ω/2Ω of order 1 or greater; here ω and Ω are the disc and background rotation frequencies, respectively. The principal flow dynamics resulting in the mixing and deformation of the initially stable density distribution were identified as (i) shear-induced mixing due to the local increase in fluid vorticity above the disc and (ii) meridional circulations produced by Ekman processes and the constraint of the container sidewall. Laboratory experiments revealed the growth of a mixed layer adjacent to the disc and the subsequent development of layers within the mixed region. Furthermore, the experiments showed that, even at relatively large ε, Ekman processes associated with background rotation constituted the dominant mechanism controlling development and evolution of the primary interface between mixed and unmixed fluid regions. Theoretical, energy-based scalings are derived to describe the growth rate of the interfacial region for εgsimScript O(1) which are consistent with the ε → ∞ limit corresponding to the Ω = 0 case. These scalings are shown to describe well the development of the density field within the forced flow

    Supernova enrichment and dynamical histories of solar-type stars in clusters

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    We use N-body simulations of star cluster evolution to explore the hypothesis that short-lived radioactive isotopes found in meteorites, such as 26-Al, were delivered to the Sun's protoplanetary disc from a supernova at the epoch of Solar System formation. We cover a range of star cluster formation parameter space and model both clusters with primordial substructure, and those with smooth profiles. We also adopt different initial virial ratios - from cool, collapsing clusters to warm, expanding associations. In each cluster we place the same stellar population; the clusters each have 2100 stars, and contain one massive 25M_Sun star which is expected to explode as a supernova at about 6.6Myr. We determine the number of Solar (G)-type stars that are within 0.1 - 0.3pc of the 25M_Sun star at the time of the supernova, which is the distance required to enrich the protoplanetary disc with the 26-Al abundances found in meteorites. We then determine how many of these G-dwarfs are unperturbed `singletons'; stars which are never in close binaries, nor suffer sub-100au encounters, and which also do not suffer strong dynamical perturbations. The evolution of a suite of twenty initially identical clusters is highly stochastic, with the supernova enriching over 10 G-dwarfs in some clusters, and none at all in others. Typically only ~25 per cent of clusters contain enriched, unperturbed singletons, and usually only 1 - 2 per cluster (from a total of 96 G-dwarfs in each cluster). The initial conditions for star formation do not strongly affect the results, although a higher fraction of supervirial (expanding) clusters would contain enriched G-dwarfs if the supernova occurred earlier than 6.6Myr. If we sum together simulations with identical initial conditions, then ~1 per cent of all G-dwarfs in our simulations are enriched, unperturbed singletons.Comment: 14 pages, 5 figures, accepted for publication in MNRA

    Autolougous platelet concentrates in esthetic medicine.

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    This narrative review summarizes current knowledge on the use of autologous platelet concentrates (APCs) in esthetic medicine, with the goal of providing clinicians with reliable information for clinical practice. APCs contain platelets that release various growth factors with potential applications in facial and dermatologic treatments. This review examines several facial esthetic applications of APCs, including acne scarring, skin rejuvenation, melasma, vitiligo, stretchmarks, peri-orbital rejuvenation, peri-oral rejuvenation, hair regeneration and the volumizing effects of APC gels. A systematic review of literature databases (PubMed/MEDLINE) was conducted up to October 2023 to identify randomized controlled trials (RCTs) in the English language on APCs for facial rejuvenation and dermatology. A total of 96 articles were selected including those on platelet rich plasma (PRP), plasma-rich in growth factors (PRGF), and platelet-rich fibrin (PRF). Clinical recommendations gained from the reviews are provided. In summary, the use of APCs in facial esthetics is a promising yet relatively recent treatment approach. Overall, the majority of studies have focused on the use of PRP with positive outcomes. Only few studies have compared PRP versus PRF with all demonstrating superior outcomes using PRF. The existing studies have limitations including small sample sizes and lack of standardized assessment criteria. Future research should utilize well-designed RCTs, incorporating appropriate controls, such as split-face comparisons, and standardized protocols for APC usage, including optimal number of sessions, interval between sessions, and objective improvement scores. Nevertheless, the most recent formulations of platelet concentrates offer clinicians an ability to improve various clinical parameters and esthetic concerns

    Methane hydrate recycling offshore of Mauritania probably after the last glacial maximum

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    To what extent methane liberated from marine hydrate will enter the ocean during a warmer world is unknown. Although methane release due to hydrate dissociation has been modelled, it is unclear whether or not methane will reach the seafloor during a warmer world and therefore contribute to oceanic and atmospheric budgets. Here we show, using a new three-dimensional (3-D) seismic dataset, that some hydrate deposits surround the gas chimneys passing through the HSZ. Bottom water warming since the last glacial maximum (LGM) is interpreted to cause hydrate dissociation but critically some of the released methane was not vented to the ocean. The released gas caused seal failure and free gas entered the hydrate stability zone (HSZ) through vertical gas chimneys to where new hydrate accumulations formed. This process is a new evidence for methane recycling and could account in part for the lack of methane in ice core records that cover warming events during the late Quaternary. This research provides new insight into how methane could be recycled rather than vented during a warmer world

    Making asset investment decisions for wastewater systems that include sustainability

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    Effective integrated water management is a key component of the World Water Vision and the way in which aspirations for water equity may be realized. Part of the vision includes the promotion of sustainability of water systems and full accountability for their interaction with other urban systems. One major problem is that “sustainability” remains an elusive concept, although those involved with the provision of urban wastewater systems now recognize that decisions involving asset investment should use the “triple bottom line” approach to society, the economy, and the environment. The Sustainable Water Industry Asset Resource Decisions project has devised a flexible and adaptable framework of decision support processes that can be used to include the principles of sustainability more effectively. Decision mapping conducted at the outset of the project has shown that only a narrow range of criteria currently influence the outcome of asset investment decisions. This paper addresses the concepts of sustainability assessment and presents two case studies that illustrate how multicriteria decision support systems can enhance the assessment of the relative sustainability of a range of options when decisions are being made about wastewater asset investment

    A national scale inventory of resource provision for biodiversity within domestic gardens

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    The human population is increasingly disconnected from nature due to urbanisation. To counteract this phenomenon, the UK government has been actively promoting wildlife gardening. However, the extent to which such activities are conducted and the level of resource provision for biodiversity (e.g., food and nesting sites) within domestic gardens remains poorly documented. Here we generate estimates for a selection of key resources provided within gardens at a national scale, using 12 survey datasets gathered across the UK. We estimate that 22.7 million households (87% of homes) have access to a garden. Average garden SiZe is 190 m(2), extrapolating to a total area of 432,924 ha. Although substantial, this coverage is still an order of magnitude less than that of statutory protected areas. Approximately 12.6 million (48%) households provide supplementary food for birds, 7.4 million of which specifically use bird feeders. Similarly, there are a minimum of 4.7 million nest boxes within gardens. These figures equate to one bird feeder for every nine potentially feeder-using birds in the UK, and at least one nest box for every six breeding pairs of cavity nesting birds. Gardens also contain 2.5-3.5 million ponds and 28.7 million trees, which is just under a quarter of all trees occurring outside woodlands. Ongoing urbanisation, characterised by increased housing densities, is inevitable throughout the UK and elsewhere. The important contribution domestic gardens make to the green space infrastructure in residential areas must be acknowledged, as their reduction will impact biodiversity conservation, ecosystem services, and the well-being of the human population
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