11,968 research outputs found
Archaeologists and Aborigines
Aboriginal hostility to archaeological work in Australia seem to be due mainly to lack of public understanding of what archaeology is all about. For this archaeologists themselves are chiefly to blame, because of their general disinclination or inability to communicate in a popular wa
Abundance and Partitioning of OH in a High-pressure Magmatic System: Megacrysts from the Monastery Kimberlite, South Africa
Concentrations of OH, and major and trace elements were determined in a suite of mantle-derived megacrysts that represent the crystallization products of a kimberlite-like magma at ~5 GPa and ~1400–1100°C. OH concentrations, determined by single-crystal Fourier transform infrared spectroscopy, display the following ranges (ppmw H2O): olivine 54–262, orthopyroxene 215–263, garnet 15–74, clinopyroxene 195–620, and zircon 28–34. High OH concentrations in olivine imply mantle conditions of origin, with limited H loss during ascent. OH is consistently correlated with megacryst composition, exhibiting trends with Mg-number that are similar to those of other minor and trace elements and indicating a record of high-pressure magmatic evolution. H substitution is not coupled to minor elements in olivine, but may be in ortho- and clinopyroxene. The OH–Mg-number trends of garnet and clinopyroxene show inflections related to co-precipitation of ilmenite, suggesting minor element (Ti) influence on OH partitioning. During differentiation, relative OH enrichment in clinopyroxene and olivine is consistent with proportional dependence on water activity, whereas that in garnet suggests a higher power-law dependence and/or influence of temperature. Inter-mineral distribution coefficients for OH between cpx, opx, olivine and zircon are thus constant, whereas partitioning between these minerals and garnet shows a factor 4–10 variation, correlated regularly with composition (and temperature). Calculation of solid–melt partition coefficients for H at 5 GPa over a range of magmatic evolution from 1380 to 1250°C yields: ol 0·0053–0·0046, opx 0·0093–0·0059, cpx 0·016–0·013, gt 0·0014–0·0003, bulk (garnet lherzolite–melt) 0·0063–0·0051. These are consistent with experimental studies and similar to values inferred from mid-ocean ridge basalt geochemistry, confirming the moderate incompatibility of H in mantle melting
Is sea-basing a viable method of providing logistic support to the UK amphibious force?
Maritime power has traditionally been a central part of the UK’s defence planning and is well
suited to supporting a wide range of military operations. The littoral area has always created
problems for naval planners as most landings historically have had to endure a tactical
separation of the naval and land components, and hence an artificial seam between the Navy
and the Marines. With the end of the Cold War, amphibious operations are going to be more
difficult to conduct than in the past, and amphibious forces are going to have to adopt
manoeuvre warfare capabilities in order to successfully complete their missions. It is very
likely that amphibious forces will have to conduct operations against a numerically superior
enemy, who is on his own terrain, and be surrounded by a neutral, if not hostile populace. As
such, the concept of Operational Manoeuvre From The Sea (OMFTS) whereby the sea is used
as a manoeuvre space, and command and control is fast enough to cope with large amounts of
information, but at the same time allow subordinates maximum flexibility to use their
initiative, is increasingly attractive. It will be important not only for the combat elements to be
able to use this new concept, but the Combat Service Support (CSS) elements as well
The client perspective on factors in the retrofitting of sustainable technologies to traditional rural homes in North East Scotland.
Through the study of a project completed in 2009, this article seeks to determine what barriers can be encountered by homeowners when trying to improve the performance of older properties with regard to energy use and CO2 emissions. The scope of the study is determined by the type of dwelling that is its focus, the traditional farmhouse as constructed during the late nineteenth and early twentieth centuries in NE Scotland, along with the boundary set by the client's interpretation of sustainability. Within this scope, this article aims to report on the decision-making process that resulted in real-world solutions to the identified barriers. Learning that results from the study relates to findings reported in the literature, particularly with regard to types of barriers encountered when attempting to mitigate against climate change by retrofitting technologies and materials to existing housing. In addition, there is learning related to the manner in which homeowners may make decisions in response to the identified barriers that result in a series of revisions of the initial list of technologies and materials. Such revisionary activity suggests that there remain significant problems to be addressed before substantial reductions in CO2 emissions from traditional dwellings can be achieved
Archaeological Data and Small Projects: A Case Study from the Pyla-Koustopetria Archaeological Project on Cyprus
A case study in how small projects use digital tools
How well can regional fluxes be derived from smaller-scale estimates?
Regional surface fluxes are essential lower boundary conditions for large scale numerical weather and climate models and are the elements of global budgets of important trace gases. Surface properties affecting the exchange of heat, moisture, momentum and trace gases vary with length scales from one meter to hundreds of km. A classical difficulty is that fluxes have been measured directly only at points or along lines. The process of scaling up observations limited in space and/or time to represent larger areas was done by assigning properties to surface classes and combining estimated or calculated fluxes using an area weighted average. It is not clear that a simple area weighted average is sufficient to produce the large scale from the small scale, chiefly due to the effect of internal boundary layers, nor is it known how important the uncertainty is to large scale model outcomes. Simultaneous aircraft and tower data obtained in the relatively simple terrain of the western Alaska tundra were used to determine the extent to which surface type variation can be related to fluxes of heat, moisture, and other properties. Surface type was classified as lake or land with aircraft borne infrared thermometer, and flight level heat and moisture fluxes were related to surface type. The magnitude and variety of sampling errors inherent in eddy correlation flux estimation place limits on how well any flux can be known even in simple geometries
New Records of Michigan Cicadidae (Homoptera), With Notes on the Use of Songs to Monitor Range Changes
We present records of Diceroprocta vitripennis, Tibicen chloromera, and Tibicen pruinosa (new state record) in Michigan. Monitoring geographic range changes and population size differences by song suggests several population situations for cicadas: (1) sizable populations in most areas of apparently good habitat; (2) widely separated single individuals or small populations on the edges of populated regions, representing range extensions that may be of limited duration; (3) one or a few individuals present only once, probably transferred in soil on roots, and ultimately unsuccessful. Species- specific calling songs allow sensitive measurement of species\u27 range changes
Female reproductive strategy predicts preferences for sexual dimorphism in male faces
The aim of the current studies was to test an assumption that variation in female preferences for sexually dimorphic male facial characteristics reflects strategic optimisation of investment in offspring. A negative relationship was predicted between ideal number of children and preferences for masculine male face shapes, as the benefits of securing paternal investment should outweigh the benefits of securing good genes as the costs of raising offspring increase. In Study 1 desired number of children and preferences for masculine face shapes were compared in a sample of female students. In study 2, the prediction was tested in a sample with a wider age profile while controlling for relationship status. Preferences for explicit partner characteristics were also assessed. The prediction was supported: women who desired a higher number of children preferred more feminine male face shapes and ranked cues to investment of parental care over cues to immunocompetence in a partner more highly than those who desired fewer children. Results indicate that female mate preferences vary with reproductive strategy and support assumptions that preferences for feminine male faces reflect preferences for “good dads”
Differentiating Text Assignments in Content Areas: Slicing the Task
There are several ways to accommodate content reading assignments with students\u27 varied reading levels. Rieck (1977) reported that many times content teachers simply do not expect their students to read the text. She found that tests given in content classrooms often covered only material from lectures and class discussions rather than text reading. In addition, students were rarely required to discuss their assigned readings
Disclosure of Children's Positive Serostatus to Family and Nonfamily Members: Informal Caregivers in Togo, West Africa
This study examined the structural constraints to disclosure of children's positive serostatus among informal caregivers to family and nonfamily members in Togo. It drew on two data sources, one qualitative and the other quantitative. Qualitative data showed that caregivers cautiously disclosed child's positive serostatus for fear of being stigmatized and discriminated against as well as to protect the children from being stigmatized. Binary regression analyses revealed that different factors influenced reasons for disclosure of a child's serostatus. For instance, while caregivers' serostatus and number of children significantly influenced disclosure for financial support, disclosure of a child's serostatus for spiritual support was strongly affected by education and religion. These results shed light on factors and reasons for disclosure among caregivers. This knowledge is important because different types of programs and advice should be given to caregivers with specific reason(s) for disclosure instead of creating a “one-size-fits all” program for all caregivers
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