475 research outputs found

    Superfast broadband and rural community resilience: examining the rural need for speed

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    This paper examines the relationship between rural dwellers and Internet technology and aims to understand how that relationship is altered with a significant increase in broadband speed. It presents an argument for using ‘resilience’ as a framework for such technological impact research, positing its potential usefulness for identifying alternative development narratives. Using interview data from 36 individuals in a study conducted with two rural community-based superfast broadband organisations in the UK, it identifies whether superfast broadband plays a role in enhancing rural community resilience. Anticipated outcomes are identified including an increased use of high-capacity services, specifically video services, and also the potential for making new patterns and habits of usage through alternative connection possibilities. Superfast access is equated to increased control over everyday actions, and the need for speed is positioned in relation to the reliability that speed provides for users. Finally, the Internet is perceived broadly as an individualised tool, one that can be accessed for personal skill building, empowerment and ultimately individual scale resilience. These findings highlight the complex, and at times contradictory nature of the relationship between superfast broadband, rural users and potential individual and community resilience. This paper concludes by identifying future research directions

    Community-led broadband in rural digital infrastructure development: implications for resilience

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    Community-led broadband initiatives represent a relatively recent shift in rural broadband provision. They are locally-led organisations that voluntarily spring up to respond to the lack, or perceived lack, of adequate broadband in their communities. Particularly present in rural spaces, few studies have investigated this mode of broadband delivery, which is gaining attention in the United Kingdom and internationally. This paper seeks to explore the implications of the participatory nature of such broadband initiatives, identifying a) whether pursuing a participatory community-led model for broadband deployment plays a role in enhancing rural social resilience, and b) specifically how leadership and informal digital champions are positioned and perceived throughout this process, and their relationship with rural social resilience. The conceptual framework of ‘social resilience’ acts as a contemporary analytical tool for understanding the impact of community-led broadband. Using findings from 56 semi-structured interviews across two phases from two community-led broadband organisations, Broadband for the Rural North (B4RN) in England and Broadband for Glencaple and Lowther (B4GAL) in Scotland, this paper contributes to both digital scholarship and the theoretical development of ‘resilience’ as a concept. Community-led broadband is shown to reflect a ‘localism’ development approach, and this process has strengthened local rural identity for individuals. The role of digital champions, as leaders in the community-led broadband movement, is key to developing the digital resource within rural communities. However, it can also be problematic, entrenching existing inequalities and feelings concerning exclusion, ultimately detracting from individuals' ability to participate. The process and the eventual presence of new technology have contributed to new spatial understandings of community identity, based on regional linkages, and new communities of interest. We conclude that community-led broadband, and in particular the leadership and participation processes, can contribute to social resilience overall, but ultimately is another example of uneven rural development

    Pharmacodynamics of the Orotomides against Aspergillus fumigatus: New Opportunities for Treatment of Multidrug-Resistant Fungal Disease.

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    F901318 is an antifungal agent with a novel mechanism of action and potent activity against Aspergillus spp. An understanding of the pharmacodynamics (PD) of F901318 is required for selection of effective regimens for study in phase II and III clinical trials. Neutropenic murine and rabbit models of invasive pulmonary aspergillosis were used. The primary PD endpoint was serum galactomannan. The relationships between drug exposure and the impacts of dose fractionation on galactomannan, survival, and histopathology were determined. The results were benchmarked against a clinically relevant exposure of posaconazole. In the murine model, administration of a total daily dose of 24 mg/kg of body weight produced consistently better responses with increasingly fractionated regimens. The ratio of the minimum total plasma concentration/MIC (Cmin/MIC) was the PD index that best linked drug exposure with observed effect. An average Cmin (mg/liter) and Cmin/MIC of 0.3 and 9.1, respectively, resulted in antifungal effects equivalent to the effect of posaconazole at the upper boundary of its expected human exposures. This pattern was confirmed in a rabbit model, where Cmin and Cmin/MIC targets of 0.1 and 3.3, respectively, produced effects previously reported for expected human exposures of isavuconazole. These targets were independent of triazole susceptibility. The pattern of maximal effect evident with these drug exposure targets was also apparent when survival and histopathological clearance were used as study endpoints. F901318 exhibits time-dependent antifungal activity. The PD targets can now be used to select regimens for phase II and III clinical trials.IMPORTANCE Invasive fungal infections are common and often lethal. There are relatively few antifungal agents licensed for clinical use. Antifungal drug toxicity and the emergence of drug resistance make the treatment of these infections very challenging. F901318 is the first in a new class of antifungal agents called the orotomides. This class has a novel mechanism of action that involves the inhibition of the fungal enzyme dihydroorotate dehydrogenase. F901318 is being developed for clinical use. A deep understanding of the relationship between dosages, drug concentrations in the body, and the antifungal effect is fundamental to the identification of the regimens to administer to patients with invasive fungal infections. This study provides the necessary information to ensure that the right dose of F901318 is used the first time. Such an approach considerably reduces the risks in drug development programs and ensures that patients with few therapeutic options can receive potentially life-saving antifungal therapy at the earliest opportunity

    Visual Orbits of Spectroscopic Binaries with the CHARA Array. III. HD 8374 and HD 24546

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    We present the visual orbits of two long period spectroscopic binary stars, HD 8374 and HD 24546, using interferometric observations acquired with the CHARA Array and the Palomar Testbed Interferometer. We also obtained new radial velocities from echelle spectra using the APO 3.5 m and Fairborn 2.0 m telescopes. By combining the visual and spectroscopic observations, we solve for the full, three-dimensional orbits and determine the stellar masses and distances to within 3% uncertainty. We then estimate the effective temperature and radius of each component star through Doppler tomography and spectral energy distribution analyses, in order to compare the observed stellar parameters to the predictions of stellar evolution models. For HD 8374, we find masses of M1 = 1.636 +/- 0.050 Msun and M2 = 1.587 +/- 0.049 Msun, radii of R1 = 1.84 +/- 0.05 Rsun and R2 = 1.66 +/- 0.12 Rsun, temperatures of Teff1 = 7280 +/- 110 K and Teff2 = 7280 +/- 120 K, and an estimated age of 1.0 Gyr. For HD 24546, we find masses of M1 = 1.434 +/- 0.014 Msun and M2 = 1.409 +/- 0.014 Msun, radii of R1 = 1.67 +/- 0.06 Rsun and R2 = 1.60 +/- 0.10 Rsun, temperatures of Teff1 = 6790 +/- 120 K and Teff2 = 6770 +/- 90 K, and an estimated age of 1.4 Gyr. HD 24546 is therefore too old to be a member of the Hyades cluster, despite its physical proximity to the group.Comment: 18 pages, 10 figures. Accepted for publication in A

    A model for reactive porous transport during re-wetting of hardened concrete

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    A mathematical model is developed that captures the transport of liquid water in hardened concrete, as well as the chemical reactions that occur between the imbibed water and the residual calcium silicate compounds residing in the porous concrete matrix. The main hypothesis in this model is that the reaction product -- calcium silicate hydrate gel -- clogs the pores within the concrete thereby hindering water transport. Numerical simulations are employed to determine the sensitivity of the model solution to changes in various physical parameters, and compare to experimental results available in the literature.Comment: 30 page

    The Orbits and Dynamical Masses of the Castor System

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    Castor is a system of six stars in which the two brighter objects, Castor A and B, revolve around each other every ∼\sim450 yr and are both short-period spectroscopic binaries. They are attended by the more distant Castor C, which is also a binary. Here we report interferometric observations with the CHARA array that spatially resolve the companions in Castor A and B for the first time. We complement these observations with new radial velocity measurements of A and B spanning 30 yr, with the Hipparcos intermediate data, and with existing astrometric observations of the visual AB pair obtained over the past three centuries. We perform a joint orbital solution to solve simultaneously for the three-dimensional orbits of Castor A and B as well as the AB orbit. We find that they are far from being coplanar: the orbit of A is nearly at right angles (92 degrees) relative to the wide orbit, and that of B is inclined about 59 degrees compared to AB. We determine the dynamical masses of the four stars in Castor A and B to a precision better than 1%. We also determine the radii of the primary stars of both subsystems from their angular diameters measured with CHARA, and use them together with stellar evolution models to infer an age for the system of 290 Myr. The new knowledge of the orbits enables us to measure the slow motion of Castor C as well, which may assist future studies of the dynamical evolution of this remarkable sextuple system.Comment: 17 pages in emulateapj format, including figures and tables. Accepted for publication in The Astrophysical Journa
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