The application of network analysis to assess the structure and function of aquatic food webs : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Ecology at Massey University, Manawatu, New Zealand

The health of aquatic communities is under threat globally by anthropogenic impacts. A healthy ecological community is one that maintains its structure and function over time in the face of disturbance (i.e., they are stable). If we are to effectively monitor change in ecological health and instigate appropriate environmental management responses, then we first need to measure ecological health appropriately. Most methods of indicating ecological health in rivers measure structural aspects of a community, with little attention given to functional aspects. Ecological network analysis (ENA) provides a range of food web metrics that can measure both structural and functional aspects of ecological communities. The aim of this thesis was to apply ENA metrics to assess the structure and function of aquatic ecosystems and explore how they may change with habitat. In a general comparison of aquatic ecosystems, I found that rivers, lakes and estuaries have structurally similar food webs, except have lower neighbourhood connectivity which is reminiscent of unstable habitats. Through species extinction simulations of aquatic energy flow networks, I showed that aquatic food webs were most stable when trophic cascades were weak and average trophic levels were small. In examining the effects of riparian deforestation in Taranaki rivers, dietary changes altered the structure of riverine macroinvertebrate communities considerably and drove greater community respiration. In the Hutt River, I modelled changes in the biomass of trout (exotic predator) and periphyton, and showed that more periphyton, but not more trout, can result in greater community temporal variability. Furthermore, increased trout and periphyton can drive more interspecific competition. I also demonstrated the need for managers to consider the impacts of decisions on adjacent ecosystems as well as target ecosystem by showing that the Hutt River and Wellington Harbour respond substantially different to increases in algal biomass. Finally in rivers differing in nutrient enrichment the Manawatu, I showed that food webs in enriched rivers may be more stable to random species loss but more susceptible to species loss from floods. Similarly to riparian deforestation, highly enriched rivers had greater community respiration (excluding microbial activity), which may exacerbate hypoxic conditions and drive the loss of sensitive species

A Tax-Based Test of the Dividend Signaling Hypothesis

We propose and implement a new test of the dividend signaling hypothesis that is designed to discriminate between dividend signaling and other theories that would account for the apparent existence of a dividend preference. Our test refines the use of data on stock price responses to dividend announcements. In particular, we study the effect of dividend taxation on the bang-for-the-buck, which we define as the share price response per dollar of dividends. Most dividend signaling models imply that an increase in dividend taxation should increase the bang-for-the-buck. In contrast, other dividend preference theories imply that an increase in dividend taxation should decrease the bang-for-the-buck. Since there have recently been considerable variation in the tax treatment of dividends, we are able to study dividend announcement effects under different tax regimes. Our central finding is that there is a strong positive relationship between dividend tax rates and the bang-for-the-buck. This result supports the dividend signaling hypothesis, and is consistent with alternatives. The paper also provides corroborating evidence based on the relationship between the bang-for-the-buck and bond ratings.

Internship Experiences for Aspiring Educational Leaders: Student Understanding and Effectiveness

The purpose of this study was to investigate East Tennessee State University alumni\u27s perceptions of the effectiveness of internship experiences as students learned the PSEL and TILS standards and the role of mentor support as they prepared for principalship. The participants obtained their administrative license and worked currently with an administrative license that is current in the state they reside. This research focused on the perception of the PESL and TILS standards, the effectiveness of the 540-hour internship experience, and the value of the site based and university mentor as the participants completed their activities in multiple settings. Findings supported that 16 out of the 17 ideas investigated had a strong positive significance, indicating they were highly supported by the data. These findings highlight the effectiveness of various aspects within aspiring principal preparation programs. Particularly noteworthy is the significance of internship experiences, which are guided by mentors from both the educational institution and the site of practice. This underscores the pivotal role these mentorship arrangements play in shaping future educational leaders. Findings revealed that participants in the program facilitated the practical application of the PESL and TILS Standards in preparation for assuming the role of a principal. Findings also supported the positive experience when participating in the 540 hours of internship hours required by the program

An investigation of a theoretical model of willingness to donate blood

The Australian Red Cross Blood Transfusion Service (ARCBTS) in Western Australian faces a major problem with periodic shortages of blood components. These shortages are expected to become more frequent and severe as demand continues to increase at a faster rate than supply. Given that only five percent of the population is registered as blood donors, clearly, the challenge for the ARCBTS is to encourage more people to become regular blood donors. The current study was undertaken to assist the ARCBTS in achieving this goal, by identifying and investigating the factors that influence people\u27s willingness to donate blood. Based on the findings of a literature review and focus groups, a conceptual model of willingness to donate blood was developed. The model included personal values, knowledge about blood donation, perceived risks associated with donating blood, and attitudes towards blood donation, as antecedents to willingness to donate

Will the United States join the Trans-Pacific Partnership, the Comprehensive and Progressive Agreement for Trans-Pacific Partnership, or neither?

This Perspective examines the conditions under which the US could re-join TPP or join CPTPP. The author notes that ratification is unlikely in the near future while observing that the US could seek to re-enter negotiations to access potential trade benefits, give effect to its investment provisions and secure influence in the Pacific Rim

Tilted Physics: A Cosmologically Dipole-Modulated Sky

Physical constants and cosmological parameters could vary with position. On the largest scales such variations would manifest themselves as gradients across our Hubble volume, leading to dipole-modulation of the cosmic microwave anisotropies. This generically leads to a correlation between adjacent multipoles in the spherical harmonics expansion of the sky, a distinctive signal which should be searched for in future data sets.Comment: 4 pages, 3 figure

Discovering a new approach to communicating architecture through the design of a school for special education

Thesis (M.C.P.)--Massachusetts Institute of Technology, Dept. of Urban Studies and Planning, 1997.Includes bibliographical references (p. 30).Communication is a shortcoming of our profession. Go ahead and ask the ordinary person on the street to name a few famous architects. Hmmm- Frank, maybe Le Corbusier, maybe. How can we express our ideas and convey our process? How can we show our design in all its glory so that the client, the funder, the trustee, the guy that pays our bills, understand its purpose, form and function? Clearly we could just write a paper. We could include a couple of models, even a walk through on videotape. We could go to the client and show him all these things and try and convince him to hire us. Then we could hope that he will tell others involved in the funding and the building what we showed him. We could do this. We do, do this. I wanted to discover a novel approach to communicating architecture. I want you to see my approach. This thesis is my new approach to th is age old problem. I believe, as do a small number of other architects and designers, that the new approach lies in the use of today's multimedia technology. Oh a big buzz word "MULTIMEDIA". What a weird word. Multi - meaning many and Media - meaning, well just about anything, pictures, video, text, audio, 3D, 20, you name it. So multimedia means lots of anything! The word tells me everything and yet it tells me nothing. Its ambiguous. You see this is just the point. I cannot tell you. I cannot show you. You need to experience it yourself. This does not mean turning on a tape and playing it from beginning to end. It means much more; it means anything. We are finally free to do anything and everything to convey our ideas as much or as little as we want, and the whole time leaving the viewer, the client, in control. This thesis is embodied in an interactive CD-ROM which is attached to this document or available from the librarians desk. It requires an interaction with the reader. This mode of interaction results from my investigation of how communication between the lay person and the architect should occur. I argue that this affords a richer and more complete understanding of a building and its purposes than do conventional methods.by Adam Douglas Halem.M.C.P