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Despite improvements in nondestructive testing (NDT) technologies, the quality assurance of concrete reinforcing bar placement is still primarily conducted with conventional methodologies, which can be time-consuming, ineffective, and damaging to the concrete components. This study investigated the performance of two commercially available cover meters and one groundpenetrating radar (GPR) device. A cover meter was found to have the greatest accuracy for depths smaller than 3.19 in. (81.0 mm), while the GPR performed better for greater depths. The effect of reinforcing bar depth, diameter, and type; neighboring reinforcing bars; and concrete conditioning on the performance of the devices was quantified. The use of epoxy-coated reinforcing bar, galvanized reinforcing bar, and stainless-steel reinforcing bar were found to have a negligible effect on cover meter accuracy. A model was developed to predict the precision of the GPR post-measurement analysis given a depth and concrete dielectric constant. [ABSTRACT FROM AUTHOR]

Humans now play a major role in altering Earth and its biota. Finding ways to ameliorate human impacts on biodiversity and to sustain and restore the ecosystem services on which we depend is a grand scientific and societal challenge. Conservation paleobiology is an emerging discipline that uses geohistorical data to meet these challenges by developing and testing models of how biota respond to environmental stressors. Here we (a) describe how the discipline has already provided insights about biotic responses to key environmental stressors, (b) outline research aimed at disentangling the effects of multiple stressors, (c) provide examples of deliverables for managers and policy makers, and (d) identify methodological advances in geohistorical analysis that will foster the next major breakthroughs in conservation outcomes. We highlight cases for which exclusive reliance on observations of living biota may lead researchers to erroneous conclusions about the nature and magnitude of biotic change, vulnerability, and resilience.

Stylistically unique black rock drawings have been discovered in Andriamamelo Cave in western Madagascar. Several image groupings comprise naturalistic scenes with anthropomorphic, zoomorphic, and therianthropic figures. These complex images are not similar to the polychrome painted symbols previously described from the Isalo region of SW Madagascar. Eight instances were noted where images and themes suggest Ptolemaic Egyptian mythological characters and symbols, some possibly of stellar constellations. One type of M-shaped figure occurred 16 times throughout the entire design field. We have not found this figure in other rock art around the Indian Ocean, except a rare occurrence in Borneo, believed to have been created about 2000 years ago. It also matches one distinctive character found in the Amharic alphabet of Ethiopia. One set of eight curvilinears resemble Arabic characters or indigenous Sorabe. Extant animals were tentatively identified, and also three of the extinct megafauna may be pictured (elephant bird, tortoise, and sloth lemur). The latter appears in an inferred hunting scene, with a hunter pointing a weapon, the giant lemur upside down, and two dogs. Images suggest connections between traditional Malagasy symbology and the disparate worlds of the island's ancient influences, both from NE Africa and Borneo. Milligram-sized samples of the black pigment were collected from an image for AMS 14C dating, but they contained insufficient carbon in aggregate. [ABSTRACT FROM AUTHOR]

Researchers are divided about the relative importance of people versus climate in triggering the Late Holocene extinctions of the endemic large-bodied fauna on the island of Madagascar. Specifically, a dramatic and synchronous decline in arboreal pollen and increase in grass pollen ca 1000 yr ago has been alternatively interpreted as evidence for aridification, increased human activity, or both. As aridification and anthropogenic deforestation can have similar effects on vegetation, resolving which of these factors (if either) led to the demise of the megafauna on Madagascar has remained a challenge. We use stable nitrogen isotope (δ15N) values from radiocarbon-dated subfossil vertebrates to disentangle the relative importance of natural and human-induced changes. If increasing aridity were responsible for megafaunal decline, then we would expect an island-wide increase in δ15N values culminating in the highest values at the time of proposed maximum drought at ca 1000 yr ago. Alternatively, if climate were relatively stable and anthropogenic habitat alteration explains the palynological signal, then we would anticipate little or no change in habitat moisture, and no systematic, directional change in δ15N values over time. After accounting for the confounding influences of diet, geographic region, and coastal proximity, we find no change in δ15N values over the past 10 000 yr, and no support for a period of marked, geographically widespread aridification culminating 900-950 yr ago. Instead, increases in grasses at around that time may signal a transition in human land use to a more dedicated agro-pastoralist lifestyle, when megafaunal populations were already in decline. Land use changes ca 1000 yr ago would have simply accelerated the inevitable loss of Madagascar's megafauna. [ABSTRACT FROM AUTHOR]

It is increasingly evident that design needs to play a role in reducing sedentary behaviour through macro- and micro-environmental changes to the built environment. Recent research explores how various environments shape health and well-being of different populations, as the findings reported in theBuilding Research & Informationspecial issue (volume 43/5) entitled ‘Physical Activity, Sedentary Behaviour and the Indoor Built Environment’ exhibit. How can this research reach a wide audience, especially those in charge of making decisions around the design of indoor environments? Research and practice in the field of the built environment and health demands cross-disciplinary and cross-sector collaborations and research results need to be appropriately communicated, translated and adapted for practical use. Practitioners can extrapolate from available research and consult best practices. Forging ahead with implementation also lends new opportunities to collaborate with researchers on evaluation. [ABSTRACT FROM PUBLISHER]