Impacts of farming practice within organic farming systems on below-ground ecology and ecosystem function

Maintaining ecosystem function is a key issue for sustainable farming systems which contribute broadly to global ecosystem health. A focus simply on the diversity of belowground organisms is not sufficient and there is a need to consider the contribution of below-ground biological processes to the maintenance and enhancement of soil function and ecosystem services. A critical literature review on the impacts of land management practices on below-ground ecology and function shows that farm management practices can have a major impact. A particular challenge for organic farming systems is to explore to what extent reduced tillage can be adopted to the benefit of below-ground ecology without critically upsetting the whole farm management balance

Development of an Instrument to Measure Self-Directedness

The purpose of this study was to develop a reliable and valid instrument to measure self-directedness in learning within the framework of the teaching-learning (TL) and learner characteristics (LC) components of the Personal Responsibility Orientation (PRO) Model of Self-Direction (Brockett & Hiemstra, 1991) among college students. Accomplishing this purpose involved two states: (a) the identification and operationization of reliable scale items that validly reflected the two components of the PRO model, and (b) the validation of the developed scale items with other related measures of self-direction. The resultant 35-item Personal Responsibility Orientation to Self-Direction in Learning Scale (PRO-SDLS) was a highly reliable (coefficient alpha = .92) instrument in the selected sample (N = 219) of graduate and undergraduate education students. Both TL and LC items were highly correlated with the scale total. The scores from the PRO-SDLS were significantly related to criterion variables thought to demonstrate self-direction. However, PRO-SDLS scores were not significantly related to professor-ratings of students\u27 self-direction. Additionally, scores from the PRO-SDLS were significantly related (r =.76, p \u3c.01) to a known instrument of self-direction (SDLRS) and accounted for additional variance beyond the SDLRS in predicting age, GPA, and class performance. Experts who examined the content of items on the PRO-SDLS rated 31 out of 35 items appearing on the final version of the PRO-SDLS as representative of the PRO model. Recommendations for further research in the on-going process of scale validation are provided as well as strategies to promote self-direction. These latter strategies include (a) allowing learner control over the TL process, (b) modeling effective learning strategies, and (c) using encouragement to support a student\u27s proximal goals

Investigation of immune correlates, and impact of human cytomegalovirus and immune activation, on tuberculosis disease risk

Background: Recent evidence implicates human cytomegalovirus (HCMV), immune activation and inflammation as risk factors for tuberculosis (TB) disease. Evidence also points towards the underappreciated importance of humoral immunity in protection against TB. Methods: This PhD thesis uses stored serum samples from an established rural Ugandan cohort to investigate associations between HCMV, inflammation and TB. Firstly, HCMV epidemiology is investigated, and levels of mycobacterial antibodies are characterised in a cross-sectional study design including over 2,000 individuals. Secondly, a nested case-control study design was employed to explore longitudinal relationships prior to TB diagnosis in 343 matched samples. Results: This work has characterised the HCMV seropositivity in this population and found that 95% of individuals are infected by age 5. Mycobacteria-specific antibody levels increased in all individuals until a plateau was reached at approximately age 20. HIV positivity and high HCMV IgG levels were independently associated with decreased levels of mycobacterial antibodies. HCMV IgG levels, but not other chronic herpes infections EBV and HSV, are associated with increased risk of TB up to 14 years prior to TB diagnosis. HCMV IgG levels, but not EBV or HSV, are positively correlated with the inflammatory serum marker IP10. Increased antibody avidity against the mycobacterial antigen mixture, PPD, showed a directional trend towards decreased risk of TB at early time points prior to TB diagnosis. Conclusions: Data presented in this thesis confirm that HCMV burden is high in this rural Ugandan population. Anti-mycobacterial antibody levels increase with age, suggestive of cumulative exposure to either antigenically related non-tuberculous mycobacteria (NTM) or to M.tb itself. This body of work provides more evidence that HCMV infection is associated with TB disease risk. As opposed to a simple binary seropositive measurement, I have found that risk of TB disease is associated with magnitude of HCMV IgG response

The Application Of A Behavior Management System To Increase Mathematics Academic Performance Of Secondary Learning Disabled Students

The author developed and implemented a behavior management program designed to aide learning disabled (LD) students in a large metropolitan school district. The objectives of the program were to help the LD students increase their grade level performance skills in mathematics, to reduce inappropriate behaviors which were interfering with their learning, and to assist the students in the development of a positive attitude toward mathematics, themselves, peers, adults and the school. The identified behaviors were: Tardiness to class, Walking around aimlessly, Unprepared for class, Talking out, Drawing and/or writing on tables, walls, desks and other school materials. The components of this program were: Orientation, Implementation, Evaluation and Recommendations. After pretest and baseline data was collected on the identified behaviors, a behavior management system was set up. The planning and program activities involved each student. Students became monitors of their own behavior using the technique of self monitoring of behavior. Learning Centers were constructed and students were assigned to these centers for specialized instructions. After 10 weeks of intensive instructions, practice drills, remediation and reinforcements, the target group of 30 students increased their mathematics academic skills and reduced the inappropriate behaviors. The results were more successful than anticipated, and it was recommended that this model be used in the school district’s program for LD students. The Annotated Bibliography had a variety of resources consulted. The Appendices included samples of implementation materials used in the program, and a dissemination package of base materials was provided to f facilitate sharing essential elements of this practicum with others

Improving supply and phosphorous use efficiency in organic farming systems

Phosphorus (P) is an essential plant nutrient that needs to be managed carefully in organic systems so that crop yield and quality remain sustainable without contributing to environmental damage, particularly that associated with eutrophication. Under organic regulations, minimally processed rock phosphate (PR) can be used to amend low P fertility soils, although the solubility is extremely low at optimum soil pH for most crop growth (pH 6.5). This paper describes a project (PLINK) which aims to develop methods of improving P efficiency on organic farms, although the same approaches may also be applicable on conventional and low-input farms. The methodologies that the project is developing include the fermentation and composting of crop waste material with PR in order to solubilise P and make it more available to the crop. Some initial results are described here. In addition, the project will investigate the alteration of the rotation to include crops or varieties with high P uptake efficiency, or roots that possess acidifying properties which improve P availability for following crops

High-Performing Students with Low Critical Thinking Skills

This study focused on selected cognitive measures, work habits, and performance patterns of students with low critical thinking skills who achieved high grades in a large entry-level course. The high-performing low critical thinkers were compared on all target variables with both low critical thinkers who achieved low grades in the course and high critical thinkers who achieved high grades. The findings point to particular work habits that instructors could promote in helping low critical thinkers improve their course performance

Ushering in a New Day for Teacher Preparation

Teachers have to be ready to manage the classroom and impact student learning on the first day of school. This round table discussion will provide an overview of a previous study that focused on the development of undergraduate students participating in a yearlong study and also engage participates in a discussion on a proposed study with graduate students. These graduate participates have life experiences and professional identities other than a teacher identity. Will these life experiences and professional identities impact the participants teacher development differently. The researchers are interested in two aspects: (1) how will the yearlong internship impact their development as a teacher and (2) how do the two groups compare

N, P and K budgets for crop rotations on nine organic farms in the UK

On organic farms, where the importation of materials to build/maintain soil fertility is restricted, it is important that a balance between inputs and outputs of nutrients is achieved to ensure both short-term productivity and long-term sustainability. This paper considers different approaches to nutrient budgeting on organic farms and evaluates the sources of bias in the measurements and/or estimates of the nutrient inputs and outputs. The paper collates 88 nutrient budgets compiled at the farm scale in 9 temperate countries. All the nitrogen (N) budgets showed an N surplus (average 83.2 kg N ha-1 year-1). The efficiency of N use, defined as outputs/inputs, was highest (0.9) and lowest (0.2) in arable and beef systems respectively. The phosphorus (P) and potassium (K) budgets showed both surpluses and deficits (average 3.6 kg P ha-1 year-1, 14.2 kg K ha-1 year-1) with horticultural systems showing large surpluses resulting from purchased manure. The estimation of N fixation and quantities of nutrients in purchased manures may introduce significant errors in nutrient budgets. Overall, the data illustrate the diversity of management systems in place on organic farms, and suggest that used together with soil analysis, nutrient budgets are a useful tool for improving the long-term sustainability of organic systems

Revitalizing the Study of Self-Directed Adult Learning

Self-directed learning has been an important research area in adult education for the past three decades, and holds much potential for future scholarship. Three areas for possible future inquiry are examined