Designing Sport Specific Physical Fitness Programs for Students with Developmental Variations

This research examined existing options for students with disabilities in the realm of organized physical activity. Findings suggest that children with physical disabilities resulting in wheelchair use and students with the cognitive disability Autism Spectrum Disorder, referred to in this paper as ASD, have limited access to organized physical activity programs, after school sport programs, and physical education. This paper explores the importance of participation in sport for all children, the various barriers to participation for children with disabilities, and the effect on inclusive physical education and organized physical activity for all students. Finally, this paper provides recommendations on how to modify existing facilities and curricula and how to create new programs that are accessible to students with developmental variations

The ability of detainment bunds to mitigate the impact of pastoral agriculture on surface water quality in the Lake Rotorua catchment : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Soil Science, Palmerston North, New Zealand

Identifying and implementing cost-effective mitigation strategies are necessary to achieve reductions in the anthropogenic phosphorus (P) and nitrogen (N) loads that contribute to eutrophication and toxic algal blooms in Lake Rotorua, in the Bay of Plenty Region on the North Island of New Zealand. Storm generated surface runoff from grazed pastures, that cover ~48% of Lake Rotorua’s catchment, contribute 67% of the total N (TN) and 43% of the total P (TP) loads delivered from the catchment to the lake. Detainment bunds (DBs) are a novel mitigation strategy targeted at decreasing nutrient and sediment losses by impeding and temporarily ponding stormflows for up to 3 days. A DB is an earthen, stormwater retention structure, approximately 1.5-2 m high and 20-80 m long, constructed on pastures across the flow path of targeted low-order ephemeral streams. Two DBs on pastures in the Lake Rotorua catchment, with 20 and 55 ha catchments, were monitored over 12 months. Nearly 20 storm events resulted in ponding at each site. Detailed hydrological analyses were conducted for each storm in order to establish water balances, as well as to analyse contaminate loads delivered to, and discharged from the DBs. Surface runoff flows were measured, and samples were collected, to determine the DB mitigation performance and to identify the processes affecting the outcomes. The DBs prevented an estimated 51-59% of the annual suspended sediment loads, 47-68% of the annual TP loads, and 57-72% of the annual TN loads delivered to the DBs in runoff, from reaching the lake. An estimated 43-63% of the annual surface runoff delivered to the DBs infiltrated the soil, as a result of increased residence times of surface runoff on well-drained pasture soils. Soil infiltration was mainly responsible for decreased contaminant loads delivered to surface waters downstream of the bunds, while sorption and sedimentation also contributed to some load reductions. The inability to impound only portions of the runoff generated during rare, high magnitude storm events limited the performance of DBs. Furthermore, declining soil infiltration rates and increasing soil P concentrations in the ponding areas could affect the longer-term performance of DBs. A cost: benefit analysis of the DB strategy was conducted in order to compare the cost-effectiveness of DBs to other nutrient migration strategies, with results demonstrating that the DB strategy is a highly cost-effective edge of field mitigation option available to pastoral farmers in the Lake Rotorua catchment

Collective signal processing in cluster chemotaxis: roles of adaptation, amplification, and co-attraction in collective guidance

Single eukaryotic cells commonly sense and follow chemical gradients, performing chemotaxis. Recent experiments and theories, however, show that even when single cells do not chemotax, clusters of cells may, if their interactions are regulated by the chemoattractant. We study this general mechanism of "collective guidance" computationally with models that integrate stochastic dynamics for individual cells with biochemical reactions within the cells, and diffusion of chemical signals between the cells. We show that if clusters of cells use the well-known local excitation, global inhibition (LEGI) mechanism to sense chemoattractant gradients, the speed of the cell cluster becomes non-monotonic in the cluster's size - clusters either larger or smaller than an optimal size will have lower speed. We argue that the cell cluster speed is a crucial readout of how the cluster processes chemotactic signal; both amplification and adaptation will alter the behavior of cluster speed as a function of size. We also show that, contrary to the assumptions of earlier theories, collective guidance does not require persistent cell-cell contacts and strong short range adhesion to function. If cell-cell adhesion is absent, and the cluster cohesion is instead provided by a co-attraction mechanism, e.g. chemotaxis toward a secreted molecule, collective guidance may still function. However, new behaviors, such as cluster rotation, may also appear in this case. Together, the combination of co-attraction and adaptation allows for collective guidance that is robust to varying chemoattractant concentrations while not requiring strong cell-cell adhesion.Comment: This article extends some results previously presented in arXiv:1506.0669

Emergent collective chemotaxis without single-cell gradient sensing

Many eukaryotic cells chemotax, sensing and following chemical gradients. However, experiments have shown that even under conditions when single cells cannot chemotax, small clusters may still follow a gradient. This behavior has been observed in neural crest cells, in lymphocytes, and during border cell migration in Drosophila, but its origin remains puzzling. Here, we propose a new mechanism underlying this "collective guidance", and study a model based on this mechanism both analytically and computationally. Our approach posits that the contact inhibition of locomotion (CIL), where cells polarize away from cell-cell contact, is regulated by the chemoattractant. Individual cells must measure the mean attractant value, but need not measure its gradient, to give rise to directional motility for a cell cluster. We present analytic formulas for how cluster velocity and chemotactic index depend on the number and organization of cells in the cluster. The presence of strong orientation effects provides a simple test for our theory of collective guidance.Comment: Updated with additional simulations. Aspects of v1 of this paper about adaptation and amplification have been extended and turned into a separate paper, and removed from the current versio