Transdisciplinary Research: a new opportunity for understanding Timor-Leste

This paper will provide a broad overview of transdisciplinary research, wicked problems and the potential opportunities that may be associated with using a transdisciplinary approach in Timor-Leste. To illustrate the potential challenges of conducting research in Timor-Leste, and the potential benefits of a transdisciplinary framework, the authors use one of the author`s research topic of Social Sustainability in Biofuel Production: a study of Timor-Leste and Brazil to provide examples and illustrate points

Hypothesized resource relationships among African planktonic diatoms

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/109870/1/lno19863161169.pd

Ethics in fieldwork: Reflections on the unexpected

© 2014: Jane Palmer, Dena Fam, Tanzi Smith, Sarina Kilham, and Nova Southeastern University. Research involving fieldwork can present the researcher with ethical dilemmas not anticipated in institutional ethics approval processes, and which offer profound personal and methodological challenges. The authors' experiences of conducting qualitative fieldwork in four distinctly different contexts are used to illustrate some of these unexpected consequences and ethical dilemmas. Issues encountered included: compromised relationships with informants which develop in unforeseen ways; engagement with traumatized informants which lead to unexpected roles for the researcher such as confidante, dealing with new information that is critical to informants' futures but could undermine the research project, and the implications of ethical decisions for research design and analysis. In our shared reflection on the four case studies in this paper, we examine anticipatory rather than reactive ways of dealing with such ethical dilemmas. Preparation and critical reflection are found to be key tools in relating to field informants, dealing with the personal challenges of undertaking field work, and developing useful research outcomes after returning home. We conclude by suggesting some issues for field researchers to consider in addition to the concerns addressed in a standard university ethics approval process

Differences in silica content between marine and freshwater diatoms

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/109821/1/lno19893410205.pd

Diatom responses to microenvironment structure within metaphyton mats

Microscale conditions within metaphyton mats affected the distribution of diatom genera. We investigated the conditions within layers of floating filamentous algal mats and changes in diatom genera over 57 days using microprobes every 2, 4, and 6 cm down through mats held in floating nets. Mats were then collected, frozen, and sliced into 2 cm layers for analysis. Filamentous algae and their diatom epiphytes were identified, counted, and analyzed for nitrogen, phosphorus, carbon, silicon, ash-free dry mass (AFDM), and chlorophyll a. Light intensity, temperature, dissolved oxygen, dry mass, and AFDM all fell significantly with increasing depth in the mat. Diatom coverage per filament was calculated as an epiphyte area index (EAI) and was significantly higher at the edge versus the center of the mat. The uppermost 2 cm layer showed the greatest downward trend in EAI over the sampling period. The density of Gomphonema, Cocconeis and Fragilaria were significantly positively correlated with lower light intensity and lower layers of the mat. Cymbella/Encyonema density was significantly correlated with higher light intensity. Gomphonema, Cocconeis and Nitzschia were positively correlated with filaments with higher chlorophyll a content. Achnanthidium, Cymbella/Encyonema and Nitzschia required higher levels of silicon. Diatoms with different growth habits responded similarly to measured variables. Stalk-forming Gomphonema and adnate Cocconeis both occurred in lower light areas and grew well under low nitrogen and phosphorus conditions

Nitrate- and silicate-competition among antarctic phytoplankton

Natural phytoplankton from antarctic waters in the Drake Passage were used for competition experiments in semicontinuous cultures. The outcome of interspecific competition for silicate and nitrate was studied at a range of Si:N ratios (from 2.6:1 to 425:1) and at three different dilution rates. For five species Monod kinetics of silicate-and nitrate-limited growth has been established. Comparison between theoretical predictions derived from Monod kinetics and the outcome of competition experiments showed only minor deviations. Contrary to literature data, considerable depletion of nitrate was found in antarctic seawater. Both the concentrations of soluble silicate and of nitrate were too low to support maximum growth rates of some of the diatom species under investigation

Evidence for the Persistence of Food Web Structure After Amphibian Extirpation in a Neotropical Stream

Species losses are predicted to simplify food web structure, and disease‐driven amphibian declines in Central America offer an opportunity to test this prediction. Assessment of insect community composition, combined with gut content analyses, was used to generate periphyton–insect food webs for a Panamanian stream, both pre‐ and post‐amphibian decline. We then used network analysis to assess the effects of amphibian declines on food web structure. Although 48% of consumer taxa, including many insect taxa, were lost between pre‐ and post‐amphibian decline sampling dates, connectance declined by less than 3%. We then quantified the resilience of food web structure by calculating the number of expected cascading extirpations from the loss of tadpoles. This analysis showed the expected effects of species loss on connectance and linkage density to be more than 60% and 40%, respectively, than were actually observed. Instead, new trophic linkages in the post‐decline food web reorganized the food web topology, changing the identity of “hub” taxa, and consequently reducing the effects of amphibian declines on many food web attributes. Resilience of food web attributes was driven by a combination of changes in consumer diets, particularly those of insect predators, as well as the appearance of generalist insect consumers, suggesting that food web structure is maintained by factors independent of the original trophic linkages