6,665 research outputs found
Cross-cultural Research, Evolutionary Psychology, and Racialism: Problems and Prospects
Philosophers defending evolutionary/cognitive accounts of racialism argue that cross-cultural psychological research has discovered similar patterns of racial reasoning around the globe. Such research, they hold, simultaneously supports the existence of an underlying cognitive mechanism for essentialist thinking while undercutting social constructionist accounts of racialism. I argue that they are mistaken for two reasons. First, evolutionary/cognitive researchers are unfamiliar with constructionist accounts of global racialism which explain similarities and differences in racialism. Second, evolutionary/cognitive accounts that make cross-cultural claims shoulder probative obligations for showing the independence of the cultures being compared, and these obligations have not been met. I argue that further evolutionary/cognitive research on racialism must account for constructionist models of global racialism while meeting the argumentative obligations of cross-cultural research
Determining The Cost Effectiveness Of Solutions To Diffuse Pollution: Developing A Model To Assess In-Field Mitigation Options for Phosphorous and Sediment Loss
The European Union Water Framework Directive requires governments to set water quality objectives based on good ecological status. This includes specific requirements to control diffuse pollution. Diffuse phosphorous (P) pollution plays a pivotal role in influencing water quality with losses of P associated with soil particles often linked to soil erosion. The Mitigation Options for Phosphorus and Sediment (MOPS) project, using three case study sites, is investigating the cost effectiveness of specific control measures in terms of mitigating sediment and P loss from combinable crops. The analysis is conducted at the farm level using a simple spreadsheet model. Further development of the model will allow the results to be extrapolated to generic regional farm typologies. Results from the initial farm level analysis suggest that some mitigation options may not be cost effective in reducing diffuse pollution, however, that other options may be very cost effective.Resource /Energy Economics and Policy,
More than Three Laws of Robotics
Wired for War: The Robotics Revolution and Conflict in the 21st Centur
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The effects of minimal tillage, contour cultivation and in-field vegetative barriers on soil erosion and phosphorus loss.
Runoff, sediment, total phosphorus and total dissolved phosphorus losses in overland flow were measured for two years on unbounded plots cropped with wheat and oats. Half of the field was cultivated with minimum tillage (shallow tillage with a tine cultivator) and half was conventionally ploughed. Within each cultivation treatment there were different treatment areas (TA). In the first year of the experiment, one TA was cultivated up and down the slope, one TA was cultivated on the contour, with a beetle bank acting as a vegetative barrier partway up the slope, and one had a mixed direction cultivation treatment, with cultivation and drilling conducted up and down the slope and all subsequent operations conducted on the contour. In the second year, this mixed treatment was replaced with contour cultivation. Results showed no significant reduction in runoff, sediment losses or total phosphorus losses from minimum tillage when compared to the conventional plough treatment, but there were increased losses of total dissolved phosphorus with minimum tillage. The mixed direction cultivation treatment increased surface runoff and losses of sediment and phosphorus. Increasing surface roughness with contour cultivation reduced surface runoff compared to up and down slope cultivation in both the plough and minimum tillage treatment areas, but this trend was not significant. Sediment and phosphorus losses in the contour cultivation treatment followed a very similar pattern to runoff. Combining contour cultivation with a vegetative barrier in the form of a beetle bank to reduce slope length resulted in a non-significant reduction in surface runoff, sediment and total phosphorus when compared to up and down-slope cultivation, but there was a clear trend towards reduced losses. However, the addition of a beetle bank did not provide a significant reduction in runoff, sediment losses or total phosphorus losses when compared to contour cultivation, suggesting only a marginal additional benefit. The economic implications for farmers of the different treatment options are investigated in order to assess their suitability for implementation at a field scale
The effect of Cichorium intybus and Lotus corniculatus on nematode burdens and production in grazed lambs
This report was presented at the UK Organic Research 2002 Conference. The study was designed to examine the hypothesis that chicory (Cichorium intybus) and Lotus sp. (Lotus corniculatus) have the potential to affect the naturally acquired nematode burden in grazed lambs. Organic male castrate lambs (48) with a naturally acquired parasite burden grazed replicate combination plots (0.6 ha) of chicory, Lotus corniculatus, perennial ryegrass (Lolium perenne) and white clover (Trifolium repens). Lamb performance was determined by weekly weight gain and condition score assessments. Nematode burden was assessed by individual lamb faecal egg count (FEC) before and after drenching (levamisole). The range of parasitic helminths present was assessed by faecal culture and by total worm counts performed on a proportion of the lambs at slaughter. Weekly pasture larval counts (PLCs) were conducted on the trial plots. A concurrent small plot study (6 x 1m2 replicates) of each of the forages used in the grazing trial was run to assess the potential effect of forage type on the development and survival of Teladorsagia circumcincta assessed by weekly PLCs. Preliminary data suggest that lambs grazing chicory or a combination of lotus and chicory had lower FECs than those grazing PRG/WC, however there was no significant difference in the total worm counts
Tur\'an Numbers of Ordered Tight Hyperpaths
An ordered hypergraph is a hypergraph whose vertex set is linearly
ordered. We find the Tur\'an numbers for the -uniform -vertex tight path
(with vertices in the natural order) exactly when and
is even; our results imply
when
r\le s}(n,P^{(r)}_s)
remain open. For , we give a construction of an -uniform -vertex
hypergraph not containing which we conjecture to be asymptotically
extremal.Comment: 10 pages, 0 figure
Formulating Rations for Horses
Formulating rations for horses may be accomplished by some rather basic mathematical calculations or by a series of complex procedures to formulate least-cost rations by computer. The most accurate method would be to consider the requirements for all nutrients--protein, energy, minerals and vitamins--in making the calculations. In practice, however, it usually is not necessary to be concerned with calculations of exact needs of all individual minerals and vitamins, since adequate amounts of trace minerals commonly are assured through inclusion of a trace mineralized salt in the ration. Other nutrients, such as the B vitamins, often are present in natural feedstuffs, or may be synthesized by bacteria present in the intestinal tract of the horse. The nutrients of major concern in horse ration formulation are energy, protein, calcium, phosphorus and vitamin A
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Basal rot of narcissus : understanding pathogenicity in fusarium oxysporum f. sp. narcissi
Fusarium oxysporum is a globally distributed soilborne fungal pathogen causing root rots, bulb rots, crown rots and vascular wilts on a range of horticultural plants. Pathogenic F. oxysporum isolates are highly host specific and are classified as formae speciales. Narcissus is an important ornamental crop and both the quality and yield of flowers and bulbs can be severely affected by a basal rot caused by F. oxysporum f. sp. narcissi (FON); 154 Fusarium isolates were obtained from different locations and Narcissus cultivars in the United Kingdom, representing a valuable resource. A subset of 30 F. oxysporum isolates were all found to be pathogenic and were therefore identified as FON. Molecular characterisation of isolates through sequencing of three housekeeping genes, suggested a monophyletic origin with little divergence. PCR detection of 14 Secreted in Xylem (SIX) genes, previously shown to be associated with pathogenicity in other F. oxysporum f. spp., revealed different complements of SIX7, SIX9, SIX10, SIX12 and SIX13 within FON isolates which may suggest a race structure. SIX gene sequences were unique to FON and SIX10 was present in all isolates, allowing for molecular identification of FON for the first time. The genome of a highly pathogenic isolate was sequenced and lineage specific (LS) regions identified which harboured putative effectors including the SIX genes. Real-time RT-PCR, showed that SIX genes and selected putative effectors were expressed in planta with many significantly upregulated during infection. This is the first study to characterise molecular variation in FON and provide an analysis of the FON genome. Identification of expressed genes potentially associated with virulence provides the basis for future functional studies and new targets for molecular diagnostics
Evidence for changes in historic and future groundwater levels in the UK
We examine the evidence for climate-change impacts on groundwater levels provided by studies of the historical
observational record, and future climate-change impact modelling. To date no evidence has been
found for systematic changes in groundwater drought frequency or intensity in the UK, but some evidence
of multi-annual to decadal coherence of groundwater levels and large-scale climate indices has been found,
which should be considered when trying to identify any trends. We analyse trends in long groundwater level
time-series monitored in seven observation boreholes in the Chalk aquifer, and identify statistically significant
declines at four of these sites, but do not attempt to attribute these to a change in a stimulus. The evidence for
the impacts of future climate change on UK groundwater recharge and levels is limited. The number of studies
that have been undertaken is small and different approaches have been adopted to quantify impacts.
Furthermore, these studies have generally focused on relatively small regions and reported local findings.
Consequently, it has been difficult to compare them between locations. We undertake some additional analysis
of the probabilistic outputs of the one recent impact study that has produced coherent multi-site projections
of changes in groundwater levels. These results suggest reductions in annual and average summer levels,
and increases in average winter levels, by the 2050s under a high greenhouse gas emissions scenario, at most
of the sites modelled, when expressed by the median of the ensemble of simulations. It is concluded, however,
that local hydrogeological conditions can be an important control on the simulated response to a future
climate projection
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