The role of earthworms in nitrogen release from herbage residues : a thesis presented in partial fulfilment of the requirements for the degree of Master of Agricultural Science in Soil Science at Massey University

Decomposition and nutrient release from pasture litter were examined in two biotic systems; either with or without large organisms ("macrobes"). Earthworms were the test macrobe and nitrogen (N) the test nutrient. This experiment addressed the hypothesis that consumption of herbage residues by macrobes, as opposed to microbes, should result in more of the contained N becoming available for uptake by plants or for loss processes, because macrobes oxidise a greater proportion of the contained carbon (C) by energetics. Earthworms influenced both soil metabolism and mineral N availability, irrespective of litter type (ryegrass or clover) and temperature (15 or 22.5 C). Carbon dioxide evolution and oxygen consumption increased by 26% and 39%, respectively, in the presence of earthworms. After an 11-week incubation about 50% more mineral N was recorded in the soils containing earthworms. Moreover, less microbial biomass was recorded in the presence of worms. This influence of macrobes carried over into a subsequent, exhaustive cropping experiment, using ryegrass as the test plant. Where soils had been previously influenced by earthworms, there was a significant increase in plant growth and N uptake. Carbon dioxide evolved during incubation was highly correlated with soil mineral N (r= 0.84** ) present at the conclusion of incubation, and also with subsequent plant dry matter yield (r= 0.75** ) and plant N yield (r=0.85** ). The link between elaborated C and contained N has long been recognised as providing stability to organic residues in soils. In the design of this experiment, other influences of macrobes (e.g. mixing or structural influences) were largely obviated, so one can conclude that nitrogen availability was increased primarily through carbon respiration by the macrobial population. These results offer a fresh perspective on the balance between mineralisation and immobilisation in the soil-plant complex and, hence, on the dynamics of nutrients contained in organic matter. Better understanding of these relationships may allow improved management of the dynamics of soil organic matter in temperate grassland ecosystems

Increasing Sustainability of Logistic Networks by Reducing Product Losses: A Network DEA Approach

This paper considers a multiproduct supply network, in which losses (e.g., spoilage of perishable products) can occur at either the nodes or the arcs. Using observed data, a Network Data Envelopment Analysis (NDEA) approach is proposed to assess the efficiency of the product flows in varying periods. Losses occur in each process as the observed output flows are lower than the observed input flows. The proposed NDEA model computes, within the NDEA technology, input and output targets for each process. The target operating points correspond to the minimum losses attainable using the best observed practice. The efficiency scores are computed comparing the observed losses with the minimum feasible losses. In addition to computing relative efficiency scores, an overall loss factor for each product and each node and link can be determined, both for the observed data and for the computed targets. A detailed illustration and an experimental design are used to study and validate the proposed approach. The results indicate that the proposed approach can identify and remove the inefficiencies in the observed data and that the potential spoilage reduction increases with the variability in the losses observed in the different periods.Ministerio de Ciencia DPI2017-85343-PFondo Europeo de Desarrollo Regional DPI2017-85343-

Linking and Weighting Efficiency Estimates with Stock Performance in Banking Firms

The purpose of this paper is to contribute further evidence on bank efficiency by defining alternative measures of costs when estimating efficiency and competitive viability by linking the results of efficiency estimates to market returns of financial institutions. Given a series of functions (production costs, opportunity costs of capital with systematic risk, opportunity cost of capital with specific risk, and branch network distribution), we estimate alternative partial measures of bank efficiency with DEA. Assuming that these functions are related to market returns on shares, an estimation of the relative importance of each of the functions is carried out, considering an additional initially unknown function which can be attributed to individual differences not accounted for in the previous four definitions. Due to the nature of the model, strong collinearity may be expected among efficiency measures. With the aid of a tabu search procedure, artificial instrumental variables are generated which avoid collinearity and permit the isolation of the underlying relationships. Results are applied to all Spanish banks quoting on the stock exchange.

A Visually-Enhanced Approach to Multivariate Calculus Facilitated by a Computer Algebra System

This study investigated the effects of a visually-enhanced approached to the teaching of selected multivariate calculus concepts on students’ mathematical understanding and visualization. The sample size consisted of 65 undergraduate students from Miami Dade College, a large Hispanic Serving Institution in the Southeast. A pretest – posttest, nonequivalent group design was used. CAS dynamic worksheets containing visualizations and geometric representations were created using a computer algebra system and embedded as part of the lecture in the experimental group. Instructor-developed instruments were used to measure students’ prerequisite knowledge for multivariate calculus, and students’ mathematical understanding of selected concepts. Furthermore, Yoon (2011)’s Revised PSVT: R was used to measure students’ spatial ability. Results from the statistical tests supported the hypothesis that enhancing the visual/geometric aspects of selected multivariate calculus concepts have a positive effect on students’ mathematical understanding and spatial ability

Mediating Role of Leadership Style on Organizational Culture and Total Quality Management

Scholars consider leadership style as a powerful tool for improving school managers’commitment on total quality management (TQM), yet few studies have empirically examinedthe linkages on organizational culture, leadership styles, and TQM in tertiary institutions.This study determined the mediating role of leadership style on organizational culture andTQM. The researcher employed the descriptive correlational design to analyze the level oforganizational culture, the extent of leadership style as mediating variable, the extent of TQMin education as perceived by the respondents, and the relationship between those variablesamong school managers. There were 295 school managers from 13 tertiary institutions inAsia who responded to the study. The results of the study showed that the respondents havevery high practices of organizational traits of involvement, adaptability, consistency, andmission with an indirect effect on leadership style. The extent of the respondents’ TQM ishigh on the following dimensions: a process-systems approach, customer-supplier focus,consistent quality leadership, continuous improvement and self-evaluation .The extent ofleadership styles in both transformational and transactional as practiced by managers is high.However, the organizational culture had no direct effect on TQM. Thus, leadership style fullymediates organizational culture and TQM. Further, the school managers are committed toTQM in education regardless of age, civil status, educational attainment, and years ofexperience. As a contribution to the mediating mechanism, the emerging model showed thattransformational and transactional being the components of leadership styles have loadings of.89 and .49, respectively. This means that the respondents’ leadership style practices havecorresponding weights of 64.49% of transformational and 35.51% of transactional leadershipstyle to fully mediate on the relationship between organizational culture and TQM. Thisresearch therefore, indicates the significance of the mediating role of leadership style onorganizational culture and TQM in tertiary institutions. The outcome of this study shall beutilized as basis for conducting seminar-workshops and training programs. The study willcontribute to future research on other dimensions on OC, LS and moderating variables inrelation to TQM