On the membership of decision making committees

Draft published as working paper in November 2000The decision of a committee is determined jointly by the votingprocess it adopts and the composition of its membership. The paper analyses the process through which committee members emerge from the eligiblepopulation and traces the consequences of this for the decisions ofthe committee. It is shown that the equilibrium committee will becomposed of representatives from the extremes of the tastedistribution. These extremes balance each other and the committeereaches a moderate decision. However, this mutual negation by theextremes is a socially wasteful use of time. Data from the UK Houseof Lords is used to illustrate these results

On the Membership of DecisionMaking Committees

Abstract: The decision of a committee is determined jointly by the voting process it adopts and the composition of its membership. The paper analyses the process through which committee members emerge from the eligible population and traces the consequences of this for the decisions of the committee. It is shown that the equilibrium committee will be composed of representatives from the extremes of the taste distribution. These extremes balance each other and the committee reaches a moderate decision. However, this mutual negation by the extremes is a socially wasteful use of time. Data from the UK House of Lords is used to illustrate these results

Preliminary study of the diversion of 283 m3 s-1 (10,000 cfs) from Lake Superior to the Missouri River basin

Trans-basin diversion is an established practice in this country. The High Plains Study authorized by the U.S. Congress in 1976 examined large-scale intra-basin diversion to replenish the depleted groundwater resources of the Ogallala aquifer. A portion of this intra-basin diversion could come from the Missouri River basin. This study presents the preliminary engineering associated with a large-scale diversion of Lake Superior water out of the Great Lakes and into the Missouri River basin in order to replace intra-basin water diverted for recharge of the Ogallala aquifer. The magnitude of the diversion is 283 m3 s-1 (10,000 cfs). The first cost of the conveyance structure is estimated at US $19.6 billion. The total length is estimated at 984 km and the total static lift including friction losses, static head, and pumping plant losses is 1130 m. It is estimated that eighteen pumping plants will be required to lift the water from Lake Superior and transport it to the Missouri Basin. This study estimated an energy requirement to move this water equivalent to the annual energy production from seven 1000-MW plants. Initial costs of these power plants is estimated at$ 7 billion.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/24926/1/0000353.pd

Order and disorder in columnar joints

Columnar joints are three-dimensional fracture networks that form in cooling basalt and several other media. The network organizes itself into ordered, mostly hexagonal columns. The same pattern can be observed on a smaller scale in desiccating starch. We show how surface boundary conditions in the desiccation of starch affect the formation of columnar joints. Under constant drying power conditions, we find a power law dependence of columnar cross-sectional area with depth, while under constant drying rate conditions this coarsening is eventually halted. Discontinuous transitions in pattern scale can be observed under constant external conditions, which may prompt a reinterpretation of similar transitions found in basalt. Starch patterns are statistically similar to those found in basalt, suggesting that mature columnar jointing patterns contain inherent residual disorder, but are statistically scale invariant

Conceptualising a Dynamic Technology Practice in Education Using Argyris and Schön's Theory of Action

Despite substantial national effort to integrate technology in education, it seems that practitioners in the education system are not working in line with the given policy. Evidence from large-scale studies of students’ technology practices at school over the last decade show disparities in student practices. The observed gap between the micro and the macro level call for a closer exploration. Research that explores the influence of social and organizational factors may be useful for understanding the processes behind such gaps. Argyris and Schön’s ‘Theory of Action’ (1978) is proposed as an example of an organizational theory that can be adopted in educational technology research to move towards understanding the complexities of technology practice. To encourage discourse and application of Argyris and Schön’s theory in the field of educational technology research, this paper introduces the theory, a review of its empirical application in research of teacher educations’ technology practice and relevant conceptual work. The paper presents a conceptual framework based on Argyris and Schön’s theory that has been developed through two recent studies, and invites its application in future research and development

Inhibitory Effects of Prior Low-dose X-irradiation on Ischemia-reperfusion Injury in Mouse Paw

We have reported that low-dose, unlike high-dose, irradiation enhanced antioxidation function and reduced oxidative damage. On the other hand, ischemia-reperfusion injury is induced by reactive oxygen species. In this study, we examined the inhibitory effects of prior low-dose X-irradiation on ischemia-reperfusion injury in mouse paw. BALB/c mice were irradiated by sham or 0.5 Gy of X-ray. At 4 hrs after irradiation, the left hind leg was bound 10 times with a rubber ring for 0.5, 1, or 2 hrs and the paw thickness was measured. Results show that the paw swelling thickness by ischemia for 0.5 hr was lower than that for 2 hrs. At 1 hr after reperfusion from ischemia for 1 hr, superoxide dismutase activity in serum was increased in those mice which received 0.5 Gy irradiation and in the case of the ischemia for 0.5 or 1 hr, the paw swelling thicknesses were inhibited by 0.5 Gy irradiation. In addition, interstitial edema in those mice which received 0.5 Gy irradiation was less than that in the mice which underwent by sham irradiation. These findings suggest that the ischemia-reperfusion injury is inhibited by the enhancement of antioxidation function by 0.5 Gy irradiation

Habitat Associations of Fish Species of Greatest Conservation Need at Multiple Spatial Scales in Wadeable Iowa Streams

Fish and habitat data were collected from 84 wadeable stream reaches in the Mississippi River drainage of Iowa to predict the occurrences of seven fish species of greatest conservation need and to identify the relative importance of habitat variables measured at small (e.g., depth, velocity, and substrate) and large (e.g., stream order, elevation, and gradient) scales in terms of their influence on species occurrences. Multiple logistic regression analysis was used to predict fish species occurrences, starting with all possible combinations of variables (5 large-scale variables, 13 small-scale variables, and all 18 variables) but limiting the final models to a maximum of five variables. Akaike’s information criterion was used to rank candidate models, weight model parameters, and calculate model-averaged predictions. On average, the correct classification rate (CCR = 80%) and Cohen’s kappa (κ = 0.59) were greatest for multiple-scale models (i.e., those including both large-scale and small-scale variables), intermediate for small-scale models (CCR = 75%; κ = 0.49), and lowest for large-scale models (CCR = 73%; κ = 0.44). The occurrence of each species was associated with a unique combination of large-scale and small-scale variables. Our results support the necessity of understanding factors that constrain the distribution of fishes across spatial scales to ensure that management decisions and actions occur at the appropriate scale

Fish Assemblage Relationships with Physical Habitat in Wadeable Iowa Streams

Fish assemblages play a key role in stream ecosystems and are influenced by physical habitat. We analyzed fish assemblages and physical habitat at 93 randomly selected sites on second- through fifth-order wadeable Iowa streams to explore fish assemblage relationships with reach-scale physical habitat in this agriculturally dominated landscape. Sites were sampled using DC electrofishing and the wadeable streams physical habitat protocol of the U.S. Environmental Protection Agency\u27s Environmental Monitoring and Assessment Program. In all, 82 species were collected, with species richness at sites averaging 14. Over 80% of the sites had fish assemblages rated as fair (53%) or poor (32%) based on a fish index of biotic integrity (FIBI). Ordination separated sites from the two major river drainages along an axis of impairment, with sites in the Missouri River drainage exhibiting lower FIBI scores than sites in the Mississippi River drainage. Physical habitat at most sites exhibited fine substrates, eroding banks, and low-gradient, nonmeandering channel and was dominated by glides. Thirty physical habitat variables describing channel morphology, channel cross section and bank morphology, fish cover, human disturbance, large woody debris, relative bed stability, residual pool, riparian vegetation, and substrate differed significantly between sites with FIBI scores rated as poor and those with FIBI scores rated as good or excellent. Eighteen physical habitat variables were significant predictors of fish assemblage metrics and FIBI in multiple linear regression models, with adjusted R 2 values ranging from 0.12 to 0.58. Seventy percent of the model coefficients reflected substrate (40%), residual pool (21%), and fish cover (9%) variables. Fish assemblages in wadeable Iowa streams are strongly associated with the quality of physical habitat. Thus, understanding and addressing the determinants of physical habitat are crucial for managing streams in Iowa and other agricultural regions