Enhanced degradation efficiency of toluene using titania/silica photocatalysis as a regeneration process

Three kinds of titania/silica pellets were prepared using the sol-gel method with surface areas of 50.4m² g-1, 421.1m².g^-1 and 89.1m².g^-1. An annular reactor was designed and built to determine the degradation efficiency of toluene and to investigate the relationship between the adsorption and desorption-photocatalytic processes. Surface area is an important factor influencing the adsorption-photocatalytic efficiency. Higher surface areas of pellets contribute to high rates of conversion of toluene. Un-reacted toluene and reaction intermediates accumulating on their surface deactivated the titania/silica catalyst. To overcome this problem, the adsorption and regeneration process were alternated in a dual reactor system. Connecting or disconnecting the toluene feed gas enabled one reactor to adsorb toluene, while the second reactor was regenerated by photocatalysis. Using UV irradiation and titania/silica pellets with high BET surface area (421.1 m².g^-1), the alternating adsorption/regeneration processes kept the degradation efficiency of toluene at 90% after 8 hours operation. By improving the adsorption-photocatalysis efficiency, and minimising the generation and accumulation of intermediate on the surface of pellets, the method extended catalyst life and maintained a high degradation efficiency of toluene.

Recolonisation of lagoon of islands, Tasmania, by Baumea Arthrophylla: the first step in regeneration of a unique ecosystem?

Lagoon of Islands was a unique ecosystem. Damming the lagoon in 1964 caused the decline of the ecosystem, destroying the original vegetation and, eventually, rendering the lagoon eutrophic. While this took place the lagoon was colonised by a macrophyte not previously noticed in the lagoon. In an effort to restore acceptable water quality, restoration of macrophyte cover was encouraged by hydrological manipulation. Recent investigations have revealed that one of the original dominant macrophyte species is recolonising the lagoon, creating an alternative management option for the lagoon.

Computer aided analysis of dental radiographic images

This paper is a result of a fruitful cooperation between the computer science and the dental diagnosis experiences. The study presents a new approach of applying computer algorithms to radiographic images of dental implantation used for bone regeneration. We focus here only on the contribution of the computer assistance to the clinical research as the periodontal therapy is beyond the scope of this paper. The proposed system is based on a pattern recognition approach, directed to recognize density changes in the intra-bony affected areas of patients. It comprises different modules with new algorithms specially designed to treat the patients’ radiographic images more accurately. The system includes digitizing, detecting the complicated region of interest (ROI), defining reference area to correct any projection discrepancy of the follow up images, and finally to extract the distinguishing features of the ROI as a basis for determining the rate of new bone density accumulation. This study is applied to two typical dental cases for a patient who received two different operations. The results are very encouraging and more accurate than traditional techniques reported before.

Daylight for sustainable regeneration of built heritage sites

Daylight is an essential contextual ingredient of place making. Research in daylighting has recently received major attention for its valuable contribution to the sustainability of the built environment. Previous research has investigated the role of daylighting in energy efficiency, its regional qualities in relation to the façade configuration, and its contribution to the sense of visual comfort. This paper argues that appropriate use of daylighting will ensure not only visual and thermal comfort in an urban setting, but also contributes to the place identity and hence sustainability of urban regeneration projects. The paper identifies the daylight variables that affect the success of the regeneration of heritage sites in Eastern Mediterranean. Daylight variables in public open spaces include a combination of sunlight, skylight and the reflected light from the facades and the ground. The Solar altitude, the geometry of sectional profiles, the reflectance of the opposing facades, the width of the street and the density of the urban built environment are examined to simulate the daylight performance in the selected heritage sites. Located in the historical Darb al-Ahmar district, Aslam Square is selected as part of one of the rehabilitation project in Cairo. This paper examines the photometric and morphological properties of the existing configuration using daylight simulation software. Various spherical projections were developed to represent full 3D visual environment. The paper calculates and analyses the direct radiation energy, the sky diffused energy and the reflected energy in the case study.

Differential calcineurin signalling activity and regeneration efficacy in diaphragm and limb muscles of dystrophic mdx mice

Calcineurin activity is essential for successful skeletal muscle regeneration in young mdx mice and in wild type mice following myotoxic injury and cryodamage. In mature myofibres of adult mdx mice, calcineurin stimulation can ameliorate the dystrophic pathology. The aim of this study was to test the hypothesis that the more severe dystrophic pathology of the diaphragm compared with hindlimb muscles of mdx mice could be attributed to aberrant calcineurin signalling and that due to ongoing regeneration calcineurin activity would be greater in muscles of adult mdx than wild type mice. Differences in markers of regeneration between tibialis anterior and diaphragm muscles were also characterised, to determine whether there was an association between regeneration efficacy and calcineurin activity in dystrophic muscles. In diaphragm muscles of adult mdx mice, the proportion of centrally nucleated fibres and developmental myosin heavy chain protein expression was lower and myogenin protein expression was higher than in tibialis anterior muscles. Calcineurin and activated NFATc1 protein content and calcineurin phosphatase activity were higher in muscles from mdx than wild type mice and calcineurin activation was greater in diaphragm than tibialis anterior muscles of mdx mice. Thus, despite greater calcineurin activity in diaphragm compared to hindlimb muscles, regeneration events downstream of myoblast differentiation and mediated by the injured myofibre were severely compromised.

Changes in contractile activation characteristics of rat fast and slow skeletal muscle fibres during regeneration

Damaged skeletal muscle fibres are replaced with new contractile units via muscle regeneration. Regenerating muscle fibres synthesize functionally distinct isoforms of contractile and regulatory proteins but little is known of their functional properties during the regeneration process. An advantage of utilizing single muscle fibre preparations is that assessment of their function is based on the overall characteristics of the contractile apparatus and regulatory system and as such, these preparations are sensitive in revealing not only coarse, but also subtle functional differences between muscle fibres. We examined the Ca²⁺- and Sr²⁺-activated contractile characteristics of permeabilized fibres from rat fast-twitch (extensor digitorum longus) and slow-twitch (soleus) muscles at 7, 14 and 21 days following myotoxic injury, to test the hypothesis that fibres from regenerating fast and slow muscles have different functional characteristics to fibres from uninjured muscles. Regenerating muscle fibres had ∼10% of the maximal force producing capacity (P_o) of control (uninjured) fibres, and an altered sensitivity to Ca²⁺ and Sr²⁺ at 7 days post-injury. Increased force production and a shift in Ca²⁺ sensitivity consistent with fibre maturation were observed during regeneration such that P_o was restored to 36–45% of that in control fibres by 21 days, and sensitivity to Ca²⁺ and Sr²⁺ was similar to that of control (uninjured) fibres. The findings support the hypothesis that regenerating muscle fibres have different contractile activation characteristics compared with mature fibres, and that they adopt properties of mature fast- or slow-twitch muscle fibres in a progressive manner as the regeneration process is completed.

The calcineurin signal transduction pathway is essential for successful muscle regeneration in mdx dystrophic mice

Although mdx mice share the same genetic defect and lack dystrophin expression as in Duchenne muscular dystrophy (DMD), their limb muscles have a high regenerative capacity that ensures a more benign phenotype and essentially normal function. The cellular pathways responsible for this enhanced regenerative capacity are unknown. We tested the hypothesis that the calcineurin signal transduction pathway is essential for the successful regeneration following severe degeneration observed in the limb muscles of young mdx mice (2–4 weeks old) and that inhibition of this pathway using cyclosporine A (CsA) would exacerbate the dystrophic pathology. Eighteen-day-old mdx and C57BL/10 mice were treated with CsA for 16 days. CsA administration severely disrupted muscle regeneration in mdx mice, but had minimal effect in C57BL/10 mice. Muscles from CsA-treated mdx mice had fewer centrally nucleated fibers and extensive collagen, connective tissue, and mononuclear cell infiltration than muscles from vehicle-treated littermates. The deleterious effects of CsA on muscle morphology were accompanied by a 30–35% decrease in maximal force producing capacity. Taken together, these observations indicate that the calcineurin signal transduction pathway is a significant determinant of successful skeletal muscle regeneration in young mdx mice. Up-regulating this pathway may have clinical significance for DMD.

Community led regeneration - experiences from London

The Community Health Project (CHP) is a community development project based in a multicultural deprived area of London, set up to tackle health inequalities. It is a partnership with the local Housing Action Trust, Health Authority and local residents and was established in 1994. The paper describes the work of the project, identifying the influences the project has been able to exert at a number of different levels: local, regional, national and international. The CHP provides a case study of how local people can act together to take part in development opportunities, with considerable and far-reaching effects. The experience of the CHP and other similar initiatives are analysed to identify elements of a framework for supporting the involvement of local communities in social and economic regeneration programs in ways that are empowering, giving local communities greater control over their lives and local resources and enabling the development of community capacity.

Discourses of regeneration in early twentieth-century Britain : from Bedlam to the Imperial War Museum

This paper examines the building that presently houses the Imperial War Museum, investigating the transformation of the archetypal ‘mad space’ of the Bethlem Royal Hospital into what has been described as the ‘biggest boy’s bedroom in London’. Following recent concerns in human geography with Imperial cities, it highlights the differing ways in which this transformation embodies a number of themes of degeneration and regeneration in early twentieth-century Britain.

TGF-Ý signalling in human skeletal muscle regeneration and diabetes

The TGF-Ý superfamily comprises a large group of proteins with many effects on muscle growth and maturation. The molecular regulation of skeletal muscle regeneration and metabolism in response to prominent superfamily members, myostatin and TGF-Ý1, were analysed, demonstrating the importance of this pathway in controlling how muscles grow and are regulated.

Green planning heritage/industrial nature : the park lands or 'regeneration reserves' of Broken Hill

Freestone (1989+) has extensively surveyed town planning visions and model communities for Australia, but one settlement has been forgotten. The significant mining settlement of Broken Hill in far western New South Wales does not figure in his thematic and historical analyses yet its park lands are so integral to its physical cultural legacy and human health that it warrants enhanced standing. In the last 2 years the Commonwealth has been considering the potential nomination of the municipality of Broken Hill for inclusion onto the National Heritage List principally due to its mining, social and economic contributions to Australia’s heritage and identity. A component in their deliberations is the Park Lands, or ‘Regeneration Reserves’, that encompass this urban settlement and its mine leaseholds. Within these Regeneration Reserves, international arid zone ecological restoration theory and practice was pioneered by Albert and Margaret Morris in the 1930s that serves as the method for all mining revegetation practice in Australia today. This paper reviews the theory and evolution of the Broken Hill Regeneration Reserves, having regard to the Adelaide Park Lands and Garden City discourses of the 1920s-30s, arguing that the Broken Hill Regeneration Reserves have a valid and instrumental position in the planning and landscape architectural histories of Australia.