A Review of Diagramming in Systems Practice and How Technologies Have Supported the Teaching and Learning of Diagramming for Systems Thinking in Practice

The educational process arguably involves a mediated discourse between teachers and learners to aid sense or meaning making for both parties. That mediation, particularly in distance teaching models, is often done through the use of educational resources, whereby teachers develop and/or select the educational resources which the learners then study or engage with through purposeful activities. Some issues or topics are so complicated or complex that words or numbers may be insufficient to represent the meanings contained within them and this is particularly relevant to systems studies which examine complex adaptive systems. Equally diagrams can break out of the linear and systematic nature of printed text to show non-linear and systemic features. This latter trait has been enhanced through the emergence in recent years of digital technologies whereby hypertext and other web applications now make it easier to create dynamic and/or interactive diagrams. And yet there has been little recent research into the influence of such technologies on the learning of systems diagramming skills at a distance. These issues are examined through a review of the literature and the reporting of previously unpublished surveys within The Open University on the value of diagrams to systems studies and the role of technology in influencing the study of diagramming in the teaching of systems thinking in practice. This review indicates that diagrams are seen as an important feature of systems studies and that digital technology can be effective in supporting the teaching and learning of systems diagramming skills at a distance. It also notes that new investigations are needed to examine whether more recent developments in digital technologies have made them more effective and/or efficient for teaching and using such skills in practice.     

Habitat use and subspecific status of Merlins, Falco columbarius , wintering in central Utah

Most ornithological literature for Utah reports the status of the Merlin ( Falco columbarius ) as rare or scarce. Only the most recently published checklists (Behle and Perry 1975, Behle et al. 1985) record it as uncommon. Likewise, a 1998 printed checklist (Utah Ornithological Society 1998) list it as uncommon. Also misrepresented in the literature are the status and distribution of the 3 rather distinct subspecies, each of which occupies dissimilar habitats during the breeding season. We made random observations of Merlins in northern Utah beginning in the 1950s and then studied them continuously between 1992 and 1997 in Utah County, Utah. During the 1992-1997 period, we were able to clearly allocate 95 males and 76 females to subspecies, including within our count 58 falcons trapped (some fitted with radio telemetry). The winter habitat in which they occurred was categorized as either urban (mainly dense residential area) or rural (agricultural lands, dairy farms, or scattered homes). There was a statistically significant ( X 2 F. c. columbarius frequenting urban areas 68% of the time, and prairie parkland-breeding F. c. richardsonii frequenting rural habitats 78% of the time.     

Genetic mapping and diagnosis of haemophilia A achieved through a BclI polymorphism in the factor VIII gene

Haemophilia A is the most common inherited bleeding disorder in man, affecting approximately 1 male in 10,000. The disease is caused by a deficiency in the gene for factor VIII, a component of the intrinsic coagulation pathway. Due to the broad range of clotting activity in normal and heterozygous females, it is often difficult to confirm the status of women at risk for carrying the disease. A genetic marker in the form of a restriction fragment length polymorphism (RFLP) within or tightly linked to the factor VIII gene would serve as a tag for the haemophilia gene, thus allowing both accurate carrier detection and improved, earlier prenatal diagnosis by chorionic villi sampling. The recent isolation of the factor VIII gene has allowed a search for RFLPs within the gene, and we report here the identification of a common polymorphism within the factor VIII gene, revealed by the restriction enzyme BclI, which can be used diagnostically in about 42% of all families. Although the disease haemophilia A has been mapped to the distal portion of Xq, the BclI RFLP makes possible higher-resolution genetic linkage mapping with respect to other polymorphic markers on this portion of the X chromosome. We have established close linkage of the factor VIII gene to several useful RFLP markers, including the highly informative marker St14. These markers should also be useful for prenatal diagnosis of haemophilia A and for detection of its carriers.     

Alteration in crossbridge kinetics caused by mutations in actin

The generation of force during muscle contraction results from the interaction of myosin and actin. The kinetics of this force generation vary between different muscle types and within the same muscle type in different species. Most attention has focused on the role of myosin isoforms in determining these differences. The role of actin isoforms has received little attention, largely because of the lack of a suitable cell type in which the myosin isoform remains constant yet the actin isoforms vary. An alternative approach would be to examine the effect of actin mutations, however, most of these cause such gross disruption of muscle structure that mechanical measurements are impossible. We have now identified two actin mutations which, despite involving conserved amino acids, can assemble into virtually normal myofibrils. These amino-acid changes in actin significantly affect the kinetics of force generation by muscle fibres. One of the mutations is not in the putative myosin-binding site, demonstrating the importance of long-range effects of amino acids on actin function.     

Breeding biology of Mountain Plovers ( Charadrius montanus ) in the Uinta Basin

The known Mountain Plover population breeding on the Myton Bench, Duchesne County, Utah, is small, composed roughly of 30 adults and young after each breeding season. Currently, its location is peripheral to the species main range. This shrub-steppe breeding habitat differs from the shortgrass prairie habitat with which this bird is historically associated. Between 1996 and 1998 we made observations at nesting sites located consistently in 2 concentrated areas surrounded by large tracts of similar habitat. Activity may be focused in these specific areas because of breeding-site fidelity; this behavior is common among most shorebirds and has been documented for the Mountain Plover in Colorado. Also, Mountain Plovers are social and tend to choose nest sites near others. Most nests in Utah were located within close proximity of mounds of white-tailed prairie dogs ( Cynomys leucurus ), and all were situated near roadways or oil well pads. Mountain Plovers were often observed with broods on these bare areas at night. We conclude that Mountain Plovers on the Myton Bench are distributed in clumped breeding colonies within large areas of apparently favorable habitat.