Improved ultrasonic standard reference blocks

A program to improve the quality, reproducibility and reliability of nondestructive testing through the development of improved ASTM-type ultrasonic reference standards is described. Reference blocks of aluminum, steel, and titanium alloys are to be considered. Equipment representing the state-of-the-art in laboratory and field ultrasonic equipment was obtained and evaluated. RF and spectral data on ten sets of ultrasonic reference blocks have been taken as part of a task to quantify the variability in response from nominally identical blocks. Techniques for residual stress, preferred orientation, and micro-structural measurements were refined and are applied to a reference block rejected by the manufacturer during fabrication in order to evaluate the effect of metallurgical condition on block response. New fabrication techniques for reference blocks are discussed and ASTM activities are summarized

NBS Building Science Series, Bulletin 150

Report issued by the National Bureau of Standards over low voltage electric thermostats. Thermostat test results are discussed. This report includes illustrations, and photographs

The potential clinical utility of intravascular ultrasound guidance in patients undergoing percutaneous coronary intervention with drug-eluting stents

AIMS: To assess the impact on clinical outcomes of intravascular ultrasound (IVUS) guidance during drug-eluting stent (DES) implantation. IVUS guidance during percutaneous coronary intervention (PCI) has been demonstrated to be useful in optimizing stent deployment. However, it is not proved that routine use of IVUS guidance with DES implantation can prevent stent thrombosis or restenosis. METHODS AND RESULTS: The clinical outcomes of 884 patients undergoing IVUS-guided intracoronary DES implantation from April 2003 to May 2006 were compared with the outcomes of a propensity-score matched population undergoing DES implantation with angiographic guidance alone. The primary endpoint of the study was definite stent thrombosis at 12 months. The secondary endpoint was major adverse cardiac events (MACE). After propensity-score matching, the two groups were well matched for clinical and angiographic characteristics. Patients undergoing IVUS-guided DES implantation underwent less direct stenting, more post-dilation, and had greater cutting balloon and rotational atherectomy use. At 30 days and at 12 months, a higher rate of definite stent thrombosis was seen in the No IVUS group (0.5 vs. 1.4%; P = 0.046) and (0.7 vs. 2.0%; P = 0.014), respectively. There were no major differences in late stent thrombosis and MACE (14.5 vs. 16.2%; P = 0.33) at 12 month follow-up between the groups. Rates of death and Q-wave myocardial infarction were similar, and there was no significant difference between groups in target vessel revascularization. However, a trend was seen in favour of the IVUS group in target lesion revascularization (5.1 vs. 7.2%; P = 0.07). IVUS guidance was an independent predictor of freedom from cumulative stent thrombosis at 12 months (adjusted HR 0.5, CI 0.1-0.8; P = 0.02). CONCLUSION: IVUS guidance during DES implantation has the potential to influence treatment strategy and reduce both DES thrombosis and the need for repeat revascularization.7 page(s

Restricted home ranges reduce children’s opportunities to connect to nature: demographic, environmental and parental influences

While many studies have documented the decline in the extent of children’s independent movements, none have explicitly evaluated the impact of this change in behaviour on opportunities to connect with nature. We estimate and compare the biodiversity values within urban children’s home ranges, and relate exposure to biodiversity to children’s perceptions and use of their neighbourhoods. We interviewed 178 children aged 9–11 years in three New Zealand cities. While children often had biodiverse areas present within 500 m of their home, their restricted home range size meant many of these natural areas fell outside of the range of their daily movements. Children’s declining independent mobility, strongly influenced by parental restrictions, appears to limit their freedom to use diverse and natural habitats within their urban neighbourhood, with use instead focused on private gardens and formal greenspaces. Development of a connection to nature in urban areas must therefore take place primarily in private gardens, which are threatened by urban planning approaches that promote dense residential developments with public rather than private greenspace

A global analysis of the impacts of urbanization on bird and plant diversity reveals key anthropogenic drivers

Urbanization contributes to the loss of the world’s biodiversity and the homogenization of its biota. However, comparative studies of urban biodiversity leading to robust generalities of the status and drivers of biodiversity in cities at the global scale are lacking. Here, we compiled the largest global dataset to date of two diverse taxa in cities: birds (54 cities) and plants (110 cities). We found that the majority of urban bird and plant species are native in the world’s cities. Few plants and birds are cosmopolitan, the most common being Columba livia and Poa annua. The density of bird and plant species (the number of species per km2) has declined substantially: only 8% of native bird and 25% of native plant species are currently present compared with estimates of non-urban density of species. The current density of species in cities and the loss in density of species was best explained by anthropogenic features (landcover, city age) rather than by non-anthropogenic factors (geography, climate, topography). As urbanization continues to expand, efforts directed towards the conservation of intact vegetation within urban landscapes could support higher concentrations of both bird and plant species. Despite declines in the density of species, cities still retain endemic native species, thus providing opportunities for regional and global biodiversity conservation, restoration and education

Reducing the extinction of experience: association between urban form and recreational use of public greenspace

Copyright © 2015 Elsevier. NOTICE: this is the author’s version of a work that was accepted for publication in Landscape and Urban Planning. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Landscape and Urban Planning, Vol. 143 (November 2015), DOI: 10.1016/j.landurbplan.2015.06.003Halting the ‘extinction of experience’, the progressive disengagement of people with the natural world, is vital to human health and wellbeing and to public support for global biological conservation. Home to the majority of humanity, urban areas are the key for engaging people with nature, raising the crucial question of how cities should best be designed to facilitate these experiences. For the purposes of maintaining local biodiversity, intensive development within a small area (land sparing) has been shown to be better than extensive development over a large area (land sharing). Here, we investigated for the first time how different city forms affect people's experience of nature, measured in terms of their use of greenspaces. We selected five pairs of land-sharing and land-sparing study regions with different coverage by greenspaces within the city of Tokyo, central Japan and used a questionnaire survey to determine the use residents made of these spaces. We found the frequency of people's recreational use of urban greenspaces was higher in urban land-sharing than land-sparing regions. Moreover, satisfaction with local green environments was also higher in land-sharing regions. This suggests a potential conflict in the design of cities between the urban form that is most desirable for the direct protection of regional biodiversity, and that which best promotes people's nature experiences and the support for its wider protection. A strong emphasis on the advantages of land sparing may increase the separation of humans from nature, and further reduce public interest in, and awareness of, biodiversity and its benefits.JSPS KAKENHINatural Environment Research Council (NERC