Production and decay of mangrove (Avicennia marina subsp. australasica) detritus and its effects on coastal benthic communities

Temperate mangrove forests have been poorly studied compared to their tropical counterparts, because they constitute just 1.4% of the global mangrove forest area. Research from tropical mangrove forests suggests they are open systems that provide a large array of ecosystem goods and services. For example, tropical mangrove forests frequently support invertebrate communities in adjacent habitats through the production, export, decomposition and uptake of organic matter. However, ecological differences between temperate and tropical mangrove forests means that information collected in tropical regions cannot be readily extrapolated to temperate systems. Therefore, it is unclear how, or if, temperate mangrove forests supply an organic subsidy to estuarine ecosystems. Here I investigate the linkages between mangrove organic matter production and the role that decomposing mangrove detritus (dead, broken down organic matter) plays in structuring estuarine benthic communities. Research was conducted at two sites (encompassing small-scale differences in sediment properties and macrofaunal communities) in Whangamata Harbour, New Zealand. The production of mangrove detritus was quantified by measuring litter production and its decomposition into detritus. A manipulative detritus addition experiment explored the role of exported mangrove detritus in structuring benthic communities of unvegetated intertidal flats. The temperate Whangamata Harbour mangrove forest produced the equivalent of 3.24 - 5.38 t DW ha-1 yr-1 of litter, which is comparable to forests at similar latitudes and overlaps with the lower range of tropical mangrove productivity. The decomposition rates of litter following summer litterfall were dependent upon the type of litter, as well as the burial state. However, hypotheses that tidal position and site would affect litter degradation rates were not supported. Leaf and wood litter that was buried in the sediment decomposed significantly slower (1.3 - 1.4 times slower) than litter on the sediment surface. Leaf litter decomposition was faster (63 days to decay by 50%) than wood and root material (460 and 316 days, respectively). Decay models predicted that wood and root material will take years to breakdown, which has implications for New Zealand mangrove removal plans, where wood and roots often remain in situ (following clearances). Finally, a manipulative detrital addition experiment found that mangrove detritus created subtle changes in the relative abundances of a few dominant taxa, rather than shifts in whole community species composition. Communities responded similarly to the addition of mangrove detritus, with the same dominant taxa responding at both experimental sites. The subtle benthic community responses to the large amount of detritus added suggests that mangrove detritus plays a relatively minor role in shaping communities on temperate intertidal flats. The studies that comprise this thesis have together shown that as a result of different input and decomposition rates of mangrove litter, temperate estuarine benthic communities are probably less reliant on mangrove productivity than tropical communities

The future of public health: the importance of workforce

Health workforce has become a major concern and a significant health policy issue around the world in recent years. With recent international and national initiatives and models being developed and implemented in Australia and other countries, it is timely to understand the need and the rationale for a better trained and educated public health workforce for the future. Much more attention should also be given to evaluation and research in this field

E-Cigarette Use Among Undergraduate Liberal Arts and Health Sciences Students: A Study Protocol

Background: Electronic cigarettes (e-cigarettes) are battery operated devices that deliver nicotine as an inhaled vapor. Use of e-cigarettes has gained in popularity since 2007, and their use is often promoted as a safer alternative to tobacco smoking. A concern among public health experts is whether e-cigarettes can be used as an alternative method for tobacco cessation or whether they lead to nicotine dependence and use of other tobacco products. Several studies have shown a higher prevalence of use of e-cigarettes among young adults between the ages of 18 and 25, but varying results on the association between their use and perceptions of harm. For the present survey, this age group was selected because, in this group, addiction to tobacco and the likelihood for adverse effects would be lower. Thus, for this group, the chances of not starting or consideration for quitting would be higher. The purpose of this study is to investigate the knowledge, attitudes, and beliefs about using tobacco products, smoking, and e-cigarettes among undergraduate students on liberal arts and health sciences campuses of a university. Methods: Participants will be invited via email and directed to a secure website where the survey can be completed anonymously. To assess knowledge, attitudes, and beliefs, the survey will include validated questions based on recommendations by the World Health Organization ((2000) appendix A)). Anticipated Results: We anticipate that the results will show an improvement in the behavioral aspect among undergraduates at the liberal arts and health sciences campuses. We also expect that results will show an improvement in knowledge among liberal arts students but less improvement in knowledge for health sciences students. Finally, we predict an overall improvement in attitudes about tobacco use and e-cigarette use

Aflatoxin Contamination and Consumer Valuation of Maize in Western Kenya

Crop Production/Industries,

Microbial responses to changes in land use

Background/Question/Methods
Land use change is one of the greatest threats to biodiversity worldwide. This is especially true for land use change that results in the destruction of intact forest, or "deforestation”. Deforestation is causing a loss of biological diversity on an unprecedented scale, especially in the Tropics. It is unclear how the majority of the biodiversity on Earth – microbial biodiversity – is responding to these extraordinary rates of deforestation. I will provide an overview of our current understanding of microbial responses to deforestation. I will focus, as an example, on our current research regarding the effects of deforestation on the diversity of arbuscular mycorrhizal fungi (AMF), bacteria and archaea within Amazon Rainforest soils. This study takes advantage of an established chronosequence of primary rainforest, pastures of various ages, and secondary rainforest to determine the effect of deforestation on the taxonomic, phylogenetic and functional diversity of soil microorganisms, assayed using culture-independent methods.

Results/Conclusions
There is increasing evidence that deforestation significantly affects microbial diversity, and that “recovery” of microbial diversity in secondary forest soils is incomplete. For example, rarefaction curves suggest that the accumulation of AMF taxa is higher for Amazon primary forest soil relative to secondary forest soil. In addition, the community composition varies with land use; three AMF taxa were shared between primary and secondary forests, seven were found only in primary forest, and three were found exclusively in secondary forest soil. We also observed that the phylogenetic diversity of AMF is more reduced in secondary forest soils than expected given the regional pool of AMF taxa.

*The audio track for talks in this symposium may be obtained at the following web address:*

*https://sites.google.com/site/esa2010symposium13audiocontent/esa2010-symposium13-audio-content

Reconstructing Merger Timelines Using Star Cluster Age Distributions: The Case of MCG+08-11-002

We present near infrared imaging and integral field spectroscopy of the centre of the dusty luminous infrared galaxy merger MCG+08-11-002, taken using the Near InfraRed Camera 2 (NIRC2) and the OH-Suppressing InfraRed Imaging Spectrograph (OSIRIS) on Keck II. We achieve a spatial resolution of ∼25 pc in the K band, allowing us to resolve 41 star clusters in the NIRC2 images. We calculate the ages of 22/25 star clusters within the OSIRIS field using the equivalent widths of the CO 2.3μm absorption feature and the Brγ nebular emission line. The star cluster age distribution has a clear peak at ages ≲ 20 Myr, indicative of current starburst activity associated with the final coalescence of the progenitor galaxies. There is a possible second peak at ∼65 Myr which may be a product of the previous close passage of the galaxy nuclei. We fit single and double starburst models to the star cluster age distribution and use Monte Carlo sampling combined with two-sided K-S tests to calculate the probability that the observed data are drawn from each of the best fit distributions. There is a >90 per cent chance that the data are drawn from either a single or double starburst star formation history, but stochastic sampling prevents us from distinguishing between the two scenarios. Our analysis of MCG+08-11-002 indicates that star cluster age distributions provide valuable insights into the timelines of galaxy interactions and may therefore play an important role in the future development of precise merger stage classification systems

Brown and white layer pullet hybrids show different fear responses towards humans, but what role does light during incubation play in that?

Good early life conditions are increasingly recognized as essential to animal welfare later in life. The use of light during incubation might improve coping capacities and welfare in later life in poultry, by more closely approximating chicken natural environments compared to the current conventional incubation in darkness. Previous studies showed that lighted incubation resulted in more lateralized chicks, a more pronounced daily behavior rhythm, earlier onset of melatonin rhythms, and lower stress reactions to various stressors after hatching. Most existing research, however, has been conducted on broilers, and little information on lighted incubation is available for laying hens. In the current research, Dekalb White and ISA Brown eggs were incubated in complete darkness or in a cycle of green 12 L:12D throughout incubation, and five fear of human tests were performed on the 387 chickens during the rearing phase. We expected dark-incubated chickens to show stronger fear responses than light-incubated chickens. That was only the case for one of 15 behavior measurements taken during the tests (p < 0.05). In addition, white layer hybrids are known to be flightier and more fearful than brown hybrids. In this study, white chickens indeed showed stronger fear responses than brown chickens in 12 of the 15 behavior measurements (p ≤ 0.002). Furthermore, we expected light during incubation to have stronger effects on white chickens than on brown chickens, because of the stronger transmission of light through white eggshells. However, the interaction between hybrid and incubation was never significant (p ≥ 0.18). Finally, contrary to our expectations, there was no effect of the incubation treatments or the hybrid on plasma corticosterone responses to a manual restraint test (p ≥ 0.36). Since there was a hybrid effect on behavior in this test, it is reasonable to think that behavior reflected coping style, rather than fear level. To conclude, the light regime used in this study does not seem as promising as expected to improve laying hen welfare. Finally, the brown hybrid was usually less fearful than the white hybrid, though there were some exceptions depending on the stressor, and that should be taken into account in research and in laying hen management

Comparing Programming Self-Esteem of Upper Secondary School Teachers to CS1 Students

Teacher self-esteem has been found to impact student learning in a number of non-computing fields. As computing slowly becomes a part of the upper secondary school (high school) curriculum in many countries, instruments designed to measure teachers’ programming self-esteem can help inform classroom practice and processes such as teacher professional development needs. This study examines if there are differences in programming self-esteem (using the Bergin Programming Self-Esteem Instrument) between upper secondary school teachers and CS1 students in Ireland. In addition this study provides evidence of validity when using this instrument (originally developed for CS1 students) to measure upper secondary school teacher programming self-esteem. To test for evidence of validity, we compared the results of the programming self-esteem construct given to upper secondary school teachers (n=130) to a recent study of programming selfesteem among CS1 students (n=693). We found evidence of both reliability and validity with teachers that aligns with the evidence found for the CS1 students, demonstrating utility for use with teacher cohorts. Comparing these findings, teachers reported statistically significantly lower programming self-esteem compared to CS1 students. Interestingly CS1 students identifying as male had a statistically significant higher programming self-esteem than those identifying as female. However, we found no statistically significant difference for teacher gender, unlike previous work. Our results indicate that teacher programming self-esteem should be given consideration in the design and implementation of professional development