Young people and ICT 2002: findings from a survey conducted in Autumn 2002

This report describes a survey that explored the attitudes and experiences of young people aged 5-18 and their parents, in relation to the use of information and communications technology (ICT) at home and at schoo

Enhancing adult student persistence: The relationship between prior learning assessment and persistence toward the baccalaureate degree

In this study of adult part-time baccalaureate students at a midwestern private liberal arts college, prior learning assessment (the PLA portfolio process) significantly predicts persistence. Logistic regression results indicate that completers of the PLA portfolio process increase their estimated probability of persistence dramatically;Part-time adult students in higher education are likely to drop out. Adult students had dropped out at double the rate of traditional age students (45% versus 23%) in a 1992 study of the 1989 entering class. In a 1994 follow-up study, highly non-traditional students (attended part-time, worked full-time, had dependents, and delayed entry into college) were the least likely to have persisted. Among highly non-traditional students, 54% had dropped out 5 years after their 1989 entry;Researchers have identified a set of background factors and process factors that play significant role in persistence. The background variables are: age, gender, educational attainment of spouse and parents, work intensity (full-time or part-time), high school performance, and prior college credits. Life changes (such as divorce, childbirth, death or illness, and job change) influence the decision to enter higher education and the decision to leave. The outcome variables (grade point average, enrollment status, financial aid, academic and social integration, and disposition) directly influence the decision to persist;Disposition factors are confidence, goal clarity, commitment, satisfaction, and sources of support;The complex interplay of background, motivation, academic performance, PLA portfolio participation, and life changes affects adult student progress throughout the process. The significant variables predicting persistence for this study are grade point average, number of prior college credits, and participation in prior learning assessment. Demographic variables were not significant;Few interventions by adult educators can have as dramatic effect on persistence as the PLA portfolio process. Students within this sample who complete the PLA portfolio process increase their probability of persistence by a minimum of 45% to a high of 281%. Students with mean GPA and mean prior credits increased their probability of persistence by 106%. Three fourths of eligible students who completed the PLA graduated versus 39% of those who did not

An investigation of dynamic human muscle function using a variable inertial loading system

This thesis has developed and utilised an inertial loading system to study human skeletal muscle power output. Specifically, the apparatus has been used to study the effects of different modes of exercise, muscle myosin isoform composition and the effects of ageing on the ability of the lower limb muscles to generate explosive power. A variable inertial loading system was designed and constructed which allowed for the sensitive detection of the rotational properties of a flywheel from which the contractile characteristics of muscle could be inferred. When housed in the Nottingham Power Rig (NPR) the peak power generated by young non-trained male subjects from a single lower limb thrust ranged from 608 - 965 Watts and was found to occur at inertial loads ranging from 0.09 - 0.22 kgm2. To investigate the low power outputs observed at the low inertial loads, where the contraction time was short, a pre release mechanism was incorporated into the flywheel assembly. Significant increases in power output of ~ 17% were achieved at the lowest inertial load (P = 0.02), if a prior build up of isometric torque was allowed prior to movement. This suggested that at the low inertial loads, without the pre release, insufficient time was allowed for the muscle to generate its maximum power output. The flywheel system was incorporated into a cycle ergometer to allow power - velocity characteristics to be examined during inertial sprint cycling. Peak power obtained in young subjects (n = 9) was significantly higher in the cycle exercise when compared with the NPR (1620 vs. 937 Watts). In contrast to the NPR where a parabolic relationship between power and inertial load was observed, during sprint cycling power plateaued above a 'critical' load. It was concluded that the repetitive acceleration of inertial loads, above this critical threshold, will always allow the expression of peak power during cycling as ultimately a velocity will be achieved which corresponds to that required for peak power generation. An analysis of the myosin heavy chain (MHC) isoform composition of the vastus lateralis muscle was performed in young and elderly male subjects (n = 14, mean age 29.4 and 73.8). The percentage MHC-II isoform composition was significantly lower in the older subjects as was the velocity at which peak power occurred (Vopt). Overall the Vopt during sprint cycling was found to be related to the percentage MHC-II composition of the vastus lateralis (R = 0 .82, P<0.001). Finally, muscle power was examined in Elite level master Olympic weightlifters (n = 54, aged 40 - 87 years) and aged matched controls. On average the weightlifters generated ~ 32% more peak power than their aged matched counterparts and required significantly higher inertial loads to express their peak power output. In spite of 'load optimisation', power declined at twice the rate of strength. The levels of power suggest a 20 year advantage for the weightlifters

HPV 20 Composite Disc Wheel Design and Production Senior Project

This project report will serve to describe the goals, objectives, and overall process of the Cal Poly Mechanical Engineering senior project team, PolyWheel, in the design and fabrication of a complete set of 20” composite disc wheels for use on a high-efficiency human powered vehicle (HPV). The project will include the manufacturing of durable and reusable molds to build the wheels in order for multiple wheel sets to be made in the future. The wheels will be designed and built to be compatible with the Cal Poly HPV Team’s 2012 race bike and by other streamlined recumbent bicycles requiring a 20” wheel. The wheels need to optimize weight, rigidity, crash survivability, and aerodynamics. Design requirements for the wheel sets are being provided by the Cal Poly HPV Team and George Leone. Funding for the materials is being provided by John Neilson

Probing short-range magnetic order in a geometrically frustrated magnet by spin Seebeck effect

Competing magnetic interactions in geometrically frustrated magnets give rise to new forms of correlated matter, such as spin liquids and spin ices. Characterizing the magnetic structure of these states has been difficult due to the absence of long-range order. Here, we demonstrate that the spin Seebeck effect (SSE) is a sensitive probe of magnetic short-range order (SRO) in geometrically frustrated magnets. In low temperature (2 - 5 K) SSE measurements on a model frustrated magnet \mathrm{Gd_{3}Ga_{5}O_{12}}, we observe modulations in the spin current on top of a smooth background. By comparing to existing neutron diffraction data, we find that these modulations arise from field-induced magnetic ordering that is short-range in nature. The observed SRO is anisotropic with the direction of applied field, which is verified by theoretical calculation.Comment: 5 pages, 4 figure

The Microbial Community of a Terrestrial Anoxic Inter-Tidal Zone: A Model for Laboratory-Based Studies of Potentially Habitable Ancient Lacustrine Systems on Mars

Evidence indicates that Gale crater on Mars harboured a fluvio-lacustrine environment that was subjected to physio-chemical variations such as changes in redox conditions and evaporation with salinity changes, over time. Microbial communities from terrestrial environmental analogues sites are important for studying such potential habitability environments on early Mars, especially in laboratory-based simulation experiments. Traditionally, such studies have predominantly focused on microorganisms from extreme terrestrial environments. These are applicable to a range of Martian environments; however, they lack relevance to the lacustrine systems. In this study, we characterise an anoxic inter-tidal zone as a terrestrial analogue for the Gale crater lake system according to its chemical and physical properties, and its microbiological community. The sub-surface inter-tidal environment of the River Dee estuary, United Kingdom (53°21'015.40" N, 3°10'024.95" W) was selected and compared with available data from Early Hesperian-time Gale crater, and temperature, redox, and pH were similar. Compared to subsurface ‘groundwater’-type fluids invoked for the Gale subsurface, salinity was higher at the River Dee site, which are more comparable to increases in salinity that likely occurred as the Gale crater lake evolved. Similarities in clay abundance indicated similar access to, specifically, the bio-essential elements Mg, Fe and K. The River Dee microbial community consisted of taxa that were known to have members that could utilise chemolithoautotrophic and chemoorganoheterotrophic metabolism and such a mixed metabolic capability would potentially have been feasible on Mars. Microorganisms isolated from the site were able to grow under environment conditions that, based on mineralogical data, were similar to that of the Gale crater’s aqueous environment at Yellowknife Bay. Thus, the results from this study suggest that the microbial community from an anoxic inter-tidal zone is a plausible terrestrial analogue for studying habitability of fluvio-lacustrine systems on early Mars, using laboratory-based simulation experiments