2,507 research outputs found
The Aboriginal rock paintings of the Churchill River
This study is a comparative examination of the age, authorship and interpretation of aboriginal rock painting sites situated on the shores of the Churchill River of northern Saskatchewan and Manitoba. The twenty presently known sites were recorded in the years 1965, 1966, 1967 and 1969 by the author.The study combines written descriptions of the sites and their settings with reproductions of the symbols found at each site. Techniques for recording and reproducing rock paintings, developed during the course of the field studies, are described.
Geographical and stylistic relationships of the paintings to other rock painting occurrences in the Canadian Shield are examined. Data derived both directly and indirectly from native Indian residents of the area is incorporated, along with historical observations on the occurrence and interpretation of the paintings. Several sets of the Churchill River paintings are at least 150 to 200 years old, while others may be considerably more recent. Specific dates of origin cannot presently be assigned to most of the sites; the potential applicability of various dating techniques is discussed. Evidence given supports an Algonkian (undoubtedly Cree) inspiration and authorship for these rock paintings, with religious observance being the basic motivation for their creation
A Buffer Stocks Model for Stabilizing Price of Staple Food with Considering the Expectation of Non Speculative Wholesaler
This paper is a study of price stabilization in the
staple food distribution system. All stakeholders experience
market risks due to some possibility causes of price volatility.
Many models of price stabilization had been developed by
employing several approaches such as floor-ceiling prices,
buffer funds, export or import taxes, and subsidies. In the
previous researches, the models were expanded to increase the
purchasing price for producer and decrease the selling price
for consumer. Therefore, the policy can influence the losses for
non-speculative wholesaler that is reflected by the descending
of selling quantity and ascending of the stocks. The objective of
this model is not only to keep the expectation of both producer
and consumer, but also to protect non-speculative wholesaler
from the undesirable result of the stabilization policy. A
nonlinear programming model was addressed to determine the
instruments of intervention program. Moreover, the result
shows that the wholesaler behavior affects the intervention
costs.
Index Terms Buffer stocks, Price stabilization, Nonlinear
programming, Wholesaler behavior
Strong and weak lensing united III: Measuring the mass distribution of the merging galaxy cluster 1E0657-56
The galaxy cluster 1E0657-56 (z = 0.296) is remarkably well-suited for
addressing outstanding issues in both galaxy evolution and fundamental physics.
We present a reconstruction of the mass distribution from both strong and weak
gravitational lensing data. Multi-color, high-resolution HST ACS images allow
detection of many more arc candidates than were previously known, especially
around the subcluster. Using the known redshift of one of the multiply imaged
systems, we determine the remaining source redshifts using the predictive power
of the strong lens model. Combining this information with shape measurements of
"weakly" lensed sources, we derive a high-resolution, absolutely-calibrated
mass map, using no assumptions regarding the physical properties of the
underlying cluster potential. This map provides the best available
quantification of the total mass of the central part of the cluster. We also
confirm the result from Clowe et al. (2004,2006a).Comment: Accepted for publication in ApJ; Version with full-resolution figures
available at
http://www.slac.stanford.edu/~marusa/Work/bradac_strong_weak_III.pd
Non-Nuclear Methods for Compaction Control of Unbound Soil and Granular Layers
In highway construction, the nuclear density gauge (NDG) is the industry standard for measuring soil density and moisture. They are widely used at state transportation agencies, however, because of their reliance on radiation, NDGs are expensive to maintain and have unique storage requirements. Operators must also earn specialized certifications and adhere to rigorous safety protocols. Equipment manufacturers have developed several non-nuclear density gauges which are more user friendly, however, their accuracy has sometimes not equaled NDGs. This comparative study evaluated the performance of the eGauge (a relatively new device) to NDGs. Over 100 soil density and moisture measurements were collected from nine field sites throughout Kentucky. At sites characterized by silt/clay and shale or stabilized clay, NDGs and the soil density eGauge produced statistically similar soil density readings, while significant differences were observed for clays and full depth reclamation (FDR). Across all sites, 82.5% of the NDG and eGauge density readings were within +/- 5% of one another. For soil moisture, readings from NDGs and the eGauge were compared to samples dried in an oven laboratory. At sites characterized by silt/clay and shale, the NDGs, eGauge, and lab samples yielded significantly different measurements, while at sites with clay the eGauge measures differed significantly from those acquired via NDGs and the lab samples. No significant differences were noted for stabilized clays. Based on raw data, 88.2% of NDG and 48.0% of eGauge soil moisture readings were within +/- 5 percentage points of the corresponding lab measurement. For most soil types, the eGauge produces sufficiently accurate readings for field use, although further study of clays and FDR is needed
Does milk cause constipation? a crossover dietary trial
The aims of this study were to: (1) determine whether replacement of cow’s milk protein with soy resolves Chronic Functional Constipation (CFC); and (2) investigate the effects of cow’s milk β casein A1 and cow’s milk β casein A2 on CFC. Children diagnosed with CFC were recruited to one of two crossover trials: Trial 1 compared the effects of cow’s milk and soy milk; Trial 2 compared the effects of cow’s milk β casein A1 and cow’s milk β casein A2. Resolution of constipation was defined as greater than eight bowel motions during a two week intervention. Thirteen children (18 to 144 months) participated in Trial 1 (6 boys, 7 girls). Nine participants who completed the soy epoch all experienced resolution (p < 0.05). Thirty-nine children (21 to 144 months) participated in Trial 2 (25 boys, 14 girls). Resolution of constipation was highest during the washout epoch, 81%; followed by cow’s milk β casein A2, 79%; and cow’s milk β casein A1, 57%; however, the proportions did not differ statistically. The results of Trial 1 demonstrate an association between CFC and cow’s milk consumption but Trial 2 failed to show an effect from type of casein. Some other component in cow’s milk common to both A1 and A2 milk may be causing a problem in these susceptible children
Contrasting vulnerability of drained tropical and high-latitude peatlands to fluvial loss of stored carbon
Carbon sequestration and storage in peatlands rely on consistently highwater tables. Anthropogenic pressures including drainage, burning, land conversion for agriculture, timber, and biofuel production, cause loss of peat-forming vegetation and exposure of previously anaerobic peat to aerobic decomposition. This can shift peatlands from net CO2 sinks to large CO2 sources, releasing carbon held for millennia. Peatlands also export significant quantities of carbon via fluvial pathways, mainly as dissolved organic carbon (DOC). We analyzed radiocarbon (14C) levels of DOC in drainage water from multiple peatlands in Europe and Southeast Asia, to infer differences in the age of carbon lost from intact and drained systems. In most cases, drainage led to increased release of older carbon from the peat profile but withmarked differences related to peat type. Very low DOC-14C levels in runoff from drained tropical peatlands indicate loss of very old (centuries to millennia) stored peat carbon. High-latitude peatlands appear more resilient to drainage; 14C measurements from UK blanket bogs suggest that exported DOC remains young (500 year) carbon in high-latitude systems. Rewetting at least partially offsets drainage effects on DOC age
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