249 research outputs found
Conductivity tomography at two frequencies
We present a new approach for crosshole radio tomography. Conductivity images of the investigated area are reconstructed from the ratio of the electric field intensities measured at two similar frequencies. The method largely avoids assumptions about the radiation pattern and in-situ intensity of the transmitting antenna, which introduce errors in conventional single-frequency crosshole electromagnetic-absorption tomography. Application of the method to field data achieved an improvement in resolution of anomalies over traditional single-frequency absorption tomography. The dual-frequency method is not a universal approach; it is suitable for moderately conductive media (>0.01 S/m) over the approximate frequency range 1-100 MHz
Social recovery and the move beyond deficit models of depression:A feminist analysis of mid-life women's self-care practices
In Australia, like other advanced liberal democracies, the adoption of a recovery orientation was hailed as a major leap forward in mental health policy and service provision. We argue that this shift in thinking about the meaning of recovery requires further analysis of the gendered dimension of self-identity and relationships with the social world. In this article we focus on how mid-life women constructed meaning about recovery through their everyday practices of self-care within the gendered context of depression. Findings from our qualitative research with 31 mid-life women identified how the recovery process was complicated by relapses into depression, with many women critically questioning the limitations of biomedical treatment options for a more relational understanding of recovery. Participant stories revealed important tacit knowledge about recovery that emphasised the process of realising and recognising capacities and self-knowledge. We identify two central themes through which women's tacit knowledge of this changing relation to self in recovery is made explicit: the disciplined self of normalised recovery, redefining recovery and depression. The findings point to the need to reconsider how both recovery discourses and gendered expectations can complicate women's experiences of moving through depression. We argue for a different conceptualisation of recovery as a social practice through which women realise opportunities to embody different 'beings and doings'. A gendered understanding of what women themselves identify is important to their well-being, can contribute to more effective recovery oriented policies based on capability rather than deficit.Full Tex
Apollo 14: Some geochemical aspects
Chemical analyses were obtained for five samples of Apollo 14 regolith fines, three 14230 core samples, soil clod 14049, breccias 14305 and 14319, 14310 basalt, and some separated phases. The chemical uniformity of these Apollo 14 samples indicates thorough mixing and/or uniform source rocks. Basalt 14310 can be matched well in composition by a four to one mixture of soil and plagioclase. The Eu(2+)/Eu(3+) ratios calculated for 14310 pigeonite and plagioclase are similar to those for Apollo 12 and 15 mare-type basalt phases; this indicates similar redox conditions. Apollo 14 samples are chemically similar to Apollo 12 and 15 KREEP as distinct from Apollo 11, 12, and 15 and Luna 16 mare-type basalts
Parasitism strategies of the Fan-tailed Cuckoo Cacomantis flabelliformis
The Fan-tailed Cuckoo Cacomantis flabelliformis inhabits thick forest, and nothing is known about how it finds the nests of its hosts, or whether it monitors the nests that it does find. We studied this cuckoo, and its hosts, for 8 breeding seasons between 2007 (August 2007–January 2008 inclusive) and 2014 (August 2014–January 2015 inclusive) on a 10-ha site in a coastal forest of south-eastern Australia, near Moruya, New South Wales. For three of these seasons, nests were monitored with cameras. The Cuckoo was recorded at the nests of only its four putative hosts at the site (White-browed Scrubwren Sericornis frontalis, Brown Thornbill Acanthiza pusilla, Superb Fairy-wren Malurus cyaneus and Variegated Fairy-wren M. lamberti). It parasitised only the nests of the White-browed Scrubwren and Brown Thornbill, but it removed either eggs or young from all other nests at which it was recorded. There was no correlation between any measure of nest activity for a host species, and parasitism of that species, and cameras at nests recorded no evidence of nest monitoring by the Cuckoo. We conclude that individual Cuckoos may be hostspecific, and that the parasitism strategy is enigmatic, but is possibly haphazard and inefficient. As a result, the Fantailed Cuckoo finds most host nests too late for successful parasitism, it spoils them to re-instigate building, and is by default a major nest-predator
Neanderthal Use of Fish, Mammals, Birds, Starchy Plants and Wood 125-250,000 Years Ago
Neanderthals are most often portrayed as big game hunters who derived the vast majority of their diet from large terrestrial herbivores while birds, fish and plants are seen as relatively unimportant or beyond the capabilities of Neanderthals. Although evidence for exploitation of other resources (small mammals, birds, fish, shellfish, and plants) has been found at certain Neanderthal sites, these are typically dismissed as unusual exceptions. The general view suggests that Neanderthal diet may broaden with time, but that this only occurs sometime after 50,000 years ago. We present evidence, in the form of lithic residue and use-wear analyses, for an example of a broad-based subsistence for Neanderthals at the site of Payre, Ardèche, France (beginning of MIS 5/end of MIS 6 to beginning of MIS 7/end of MIS 8; approximately 125–250,000 years ago). In addition to large terrestrial herbivores, Neanderthals at Payre also exploited starchy plants, birds, and fish. These results demonstrate a varied subsistence already in place with early Neanderthals and suggest that our ideas of Neanderthal subsistence are biased by our dependence on the zooarchaeological record and a deep-seated intellectual emphasis on big game hunting
Time-resolved single-crystal X-ray crystallography
In this chapter the development of time-resolved crystallography is traced from its beginnings more than 30 years ago. The importance of being able to “watch” chemical processes as they occur rather than just being limited to three-dimensional pictures of the reactant and final product is emphasised, and time-resolved crystallography provides the opportunity to bring the dimension of time into the crystallographic experiment. The technique has evolved in time with developments in technology: synchrotron radiation, cryoscopic techniques, tuneable lasers, increased computing power and vastly improved X-ray detectors. The shorter the lifetime of the species being studied, the more complex is the experiment. The chapter focusses on the results of solid-state reactions that are activated by light, since this process does not require the addition of a reagent to the crystalline material and the single-crystalline nature of the solid may be preserved. Because of this photoactivation, time-resolved crystallography is often described as “photocrystallography”. The initial photocrystallographic studies were carried out on molecular complexes that either underwent irreversible photoactivated processes where the conversion took hours or days. Structural snapshots were taken during the process. Materials that achieved a metastable state under photoactivation and the excited (metastable) state had a long enough lifetime for the data from the crystal to be collected and the structure solved. For systems with shorter lifetimes, the first time-resolved results were obtained for macromolecular structures, where pulsed lasers were used to pump up the short lifetime excited state species and their structures were probed by using synchronised X-ray pulses from a high-intensity source. Developments in molecular crystallography soon followed, initially with monochromatic X-ray radiation, and pump-probe techniques were used to establish the structures of photoactivated molecules with lifetimes in the micro- to millisecond range. For molecules with even shorter lifetimes in the sub-microsecond range, Laue diffraction methods (rather than using monochromatic radiation) were employed to speed up the data collections and reduce crystal damage. Future developments in time-resolved crystallography are likely to involve the use of XFELs to complete “single-shot” time-resolved diffraction studies that are already proving successful in the macromolecular crystallographic field.</p
- …