Factors affecting phosphate concentrations in surface and subsurface runoff from steep East Coast hill country : a thesis presented in partial fulfilment of the requirements for the degree of Masters of Applied Science, Department of Soil Science, Massey University

Eutrophication is a problem receiving much attention within New Zealand and throughout the rest of the world. Problems associated with eutrophication cause major financial, aesthetic and recreational costs to not only commercial and recreational water users but to society in general. The major nutrient of concern in relation to eutrophication is phosphorus (P) as it is often considered to be the limiting factor. The two major areas from which P enters waterways are point sources and non-point sources. Point sources are relatively easy to identify and quantify. Non-point sources however, are less easy to quantify due to the size of areas from which P is sourced and the number of varying factors which can affect the amount of P which is lost to water-ways. This study investigated P concentrations in surface runoff and subsurface flow from steep east coast hill country. Factors studied included aspect, soil P status, season and fertiliser addition. The study was carried out on grazed pasture farmlets, in which there were 'High P' and 'Low P' fertiliser regimes. Each regime had north and south facing aspects. Four sites were used in the study. High P North (HPN), High P South (HPS), Low P North (LPN) and Low P South (LPS). Simulated rainfall was applied to the sites and surface runoff samples were collected and analysed for dissolved reactive phosphate concentration (DRP). Superphosphate fertiliser was then applied at 20 kg P ha-1 to each site and the runoff procedure was repeated 7 weeks and 14 weeks the lower P soil test values on the south-facing slopes. A water extractable P test provided a better correlation with runoff DRP concentrations for individual runoff events than the Olsen P test. Both tests however, provided poor correlations when all of the Runs were combined. This was due largely to the large increase in DRP concentrations in surface runoff in Run 3 with no corresponding increase in soil tests. There was no apparent relationship between fertiliser regime i.e. soil P status, and the concentration of DRP in subsurface runoff. In Run 3 however, there was a marked increase in subsurface DRP concentration for both sites which was consistent with the surface runoff results and supported the theory of soil moisture playing a major role in determining the DRP concentration in water. The study suggests that the greatest risk of P loss from soil to surface waters will be from northerly aspects with high fertiliser histories during the summer months when soil moisture levels are low

Teaching the use and selection of newspapers to social studies pupils in the secondary schools of greater Boston.

Thesis (Ed.M.)--Boston Universit

The value of chemical defense: the effects of toxin milking on the physical, physiological, and behavioral performance of cane toads (Rhinella marina)

Amphibians have cutaneous glands on their skin which produce a number of toxic compounds that serve as protection against predators and microorganisms. Cane toads (Rhinella marina) have large parotoid glands located on their shoulders to store toxins, many of which are derived from lipids and are thus energetically expensive to produce. I used a combination of field and laboratory studies to investigate behavioral and physiological consequences of toxin loss and replenishment in cane toads. In a cross-sectional study, free-ranging toads were euthanized and dissected to identify correlations between toxin content and morphology /physiology. Experimental manipulations (manually expressing toxin from glands) were performed to mimic a predator encounter that resulted in toads expelling their toxin in defense. A control group for this manipulation consisted of individuals whose glands were squeezed in a manner that did not express the toxin. Manipulations were carried out in both captivity and in the field. In both settings, growth rate, behavior, activity and energy allocation (relative organs masses) were compared between de-toxined and control toads. A significant negative correlation between toxin content and liver mass was evident among wild toads. The experimental manipulation of removing toxin affected change in body mass in both captive and radio-tracked wild toads. However, the effect on mass changed differed between captive and wild settings. De-toxined toads that were fasted exhibited poorer locomotor performance than their control counterparts. However, toxin milking had no significant effect on personality traits, such as boldness, or foraging skills. Radio-tracking demonstrated that de-toxined toads also disperse more slowly than the control toads, preferring to stay closer to the water source at which they were originally captured. I found evidence of physiological and behavioral costs associated with toxin removal, Blennerhassett 3 even over a relatively short period (5-20 days). Therefore, toxin may represent a precious commodity to its host and may only be deployed as a last line of defense. Key words: Bufo marinus, parotoid glands, radio-telemetry, toxin production, toxin replenishment

Selectivity In Junctional Communication

The regulation of gap junction permeability may be important during development, since this could change the nature and rate of movement of molecules passing between cells. Results in developing insect epidermis show that intercellular channels close in a graded fashion, altering the kind of substances passing between cells over time, and that reduced junctional permeability at the intersegmental border establishes spatial patterns of coupling within the epidermis.;The nature of channel closure, which might be graded or all-or-none, determines how junctional permeability changes when the coupling level is varied. The passage of small fluorescent dyes and inorganic ions between cells was examined during gradual uncoupling by Li of epidermis from the beetle Tenebrio molitor. The junctional resistance increases monotonically over 60 minutes, but the intercellular passage of the fluorescent tracers carboxyfluorescein (CF) and lissamine rhodamine B (LRB) is blocked long before electrical coupling is lost. There is discrimination by size, since LRB, with a limiting dimension for channel passage of 14A, is blocked before CF (12A). This suggests that intermediate levels of coupling are selective, and indicates that the average channel diameter decreases during uncoupling.;The cells in adjacent segments develop largely independently of each other, under the control of separate morphogenetic gradients, but the epidermis is continuous and there is cooperation in cuticle synthesis. Regulation of intercellular communication at the intersegmental boundary may be responsible, since in the bug Oncopeltus fasciatus, LRB, CF and Lucifer yellow move freely between cells within the segment but are impeded from passage to the adjacent segment. A strip of cells at the segment border has reduced junctional permeability, which is modulated independently of that within the segment. Under conditions that block the passage of dye, electrical coupling between segments remains strong, although an increase in junctional resistance of the border cells can be detected. Exposure to the molting hormone 20-hydroxyecdysone removes the barrier to intersegmental dye spread. This suggests that while depressed junctional coupling normally limits segmental interaction, developmental regulation ensures full cooperation at critical times

Development and Implementation of a Nutrition Knowledge Questionnaire for Ultra-Endurance Athletes

The nutritional intake of ultra-endurance athletes is often poorly matched with the requirements of the sport. Nutrition knowledge is a mediating factor to food choice that could correct such imbalances. Therefore, the purpose of this study was to develop and validate a questionnaire to assess the nutrition knowledge of ultra-endurance athletes. Nutritional knowledge was assessed using a modified sports nutrition questionnaire (ULTRA-Q). Four independent assessors with specialist sports nutrition knowledge confirmed the content validity of the ULTRA-Q. Registered Sports Nutritionists, Registered Dietitians, and those without nutrition training completed the ULTRA-Q on two separate occasions. After the first completion, a significant difference in nutrition scores between groups (p = <0.001) provided evidence of construct validity. After the second completion, intra-class correlation coefficients comparing nutrition scores between time points (0.75–0.95) provided evidence of test-retest reliability. Subsequently, experienced ultra-endurance athletes (male n = 74, female n = 27) completed the ULTRA-Q. Athletes also documented their sources of nutrition knowledge for ultra-endurance events. The total nutrition knowledge score for ultra-endurance athletes was 68.3 ± 9.5% and there were no significant differences in knowledge scores between males and females (67.4 ± 9.6% and 70.7 ± 9.3%) or runners and triathletes (69.1 ± 9.7% and 65.1 ± 9.4%). In general, it appeared that ultra-endurance athletes favoured other athletes (73%) over nutrition experts (8%) as a source of nutritional information. The findings of this study indicate that ultra-endurance athletes had a reasonable level of nutrition knowledge, but inter-athlete variability suggests a need for targeted nutrition education