Master's work developed in IMAE
Rachel Brockamp, Canada - 2018/2020
Coupled Iron Reduction-Ammonium Oxidation (Feammox) in Alkaline Soils Polluted With Nitrogen.
Applying nitrogen (N) fertilizers to N-limited soils can stimulate plant and microbe growth, increasing yield. However, applying excess N fertilizer can cause adverse side effects such as groundwater and surface water pollution, greenhouse gas production, soil acidification, and health issues among humans and wildlife. Common N fertilizers can include ammonium (NH4+), nitrite (NO2-), and nitrate (NO3-). The average soil N input and NH3 emissions have increased in Canada over the past 40 years, and the consequences are becoming apparent. Excess wastewater and groundwater N is typically treated via wastewater treatment plants and permeable reactive barriers. These technologies stimulate two N-removal pathways, denitrification and anaerobic ammonium oxidation (Anammox), which consume NO3- and/or NO2- and/or NH4+ and generate inert nitrogen gas (N2). However, a promising alternative N-removal pathway may improve bioremediation, but has not been explored in Canadian soils. In this iron ammonium oxidation (Feammox) pathway, ferric iron (Fe) is reduced to ferrous iron and NH4+ is oxidized to NO2- or N2.
I explored Feammox activity in alkaline soils from a N-polluted site in Alberta. I prepared oxygen-free (anaerobic) soil slurries and applied treatment combinations of ferric citrate, ferrihydrite, and NH4Cl in a 118-day anaerobic incubation. My purpose was to discover which amendment combinations stimulated the greatest NH4+-N loss via four biostimulation experiments during the incubation. I found that adding ferric citrate and NH4Cl concurrently simulated the greatest dissolved NH4+-N loss, with 49 ± 6.7% and 58 ± 20.8% dissolved NH4+-N loss in two of the biostimulation experiments. Furthermore, evidence of Fe reduction was apparent in the first of those biostimulation experiments. Although ferrihydrite successfully stimulated Feammox in previous work that involved acidic soils, ferrihydrite did not stimulate significant NH4+-N loss in my incubation. These results imply that ferric citrate is more bioavailable and stimulated greater dissolved NH4+ loss than ferrihydrite in near-neutral to alkaline pH conditions, which is important for future bioremediation research.
Lola Visschers, Australia - 2018/2020
Tracing wetland responses to saltwater intrusion along the coast of Amapá state, Brazil.
Coastal wetlands in the state of Amapá contribute significant ecosystem services to the environmental, social and economic sectors of the region. Climate change, however, threatens these coastal wetlands by changing local hydrological regimes. In this study, GIS and remote sensing techniques were used to survey mangroves as an indicator of saltwater intrusion to understand the historical coastal dynamics of the Amapá region over a period of 35 years. There was a significant gain of mangrove area over the study period, with the main gains occurring inland. Notably, mangroves appeared to grow alongside extending rivers and channels, indicating the presence of saltwater intrusion. Sea level rise was identified as a significant predictor of mangrove area while coastal erosion was not a significant predictor. It is necessary to understand historical coastal wetland dynamics in order to anticipate future trends. The ability to predict future threats is important in designing effective management strategies and adaptation plans that will protect coastal societies and ecosystems against saltwater intrusion.
Oscar Rojas Castillo: Monitoring the invasive dinoflagellate Ceratium furcoides, its drivers, and consequences in the phytoplanktonic community of Marrecas a high altitude subtropical reservoir in Rio Grande do Sul, Brazil.
Bichitra Paul: Characterisation of the cytokinin-mediated biocontrol activity of Chlamydomonas reinhardtii against Pseudomonas syringae in Tobacco and analysis of its potential as a bio-stimulant.
My Thesis in 3 minutes
My Thesis in 3 minutes
My Thesis in 3 minutes
Using a machine learning technology to recognize galápagos sea turtles. An image recognition algorithm in social media pictures to identify individuals, associate these individuals with locations and monitor their migration patterns in real time - Alban Emmanuel Mazars Simon
Oscar Rojas Castillo is an IMAE student from Guatemala. He is part of the 2017-2019 IMAE edition and he choose to continue at the University of Coimbra (UC) to work on his thesis project: Monitoring the invasive dinoflagellate Ceratium furcoides, its drivers, and consequences in the phytoplanktonic community of Marrecas a high altitude subtropical reservoir in Rio Grande do Sul, Brazil.
Ceratium furcoides is an invasive species for South American freshwaters which blooms promote anoxic conditions threatening the local biota and decreasing the quality of the hydric resource. In 2013, C. furcoides was recorded for the first time in Marrecas, a water reservoir built to provide the city of Caxias do Sul in Brazil. It is of vital importance to understand the drivers of this dinoflagellate along with the consequences associated with the invader in the water reservoir and it’s planktonic community. Therefore, Data of the phytoplanktonic community and physicochemical parameters from 2014 till 2018 was analysed unveiling the physico-chemical and climatic drivers along with the planktonic interactions between the invader and the local community in this new environment.
Although Oscar is defending his thesis at UC, he had the opportunity to carry out her work at the Federal University of Rio Grande do Sul, Brazil under the supervision of Professor Luciana De Souza Cardoso.
Mari Gigauri is an IMAE student from Georgia. She is part of the 2017-2019 IMAE edition and she choose to continue at the University of Coimbra (UC) to work on her thesis project: Use of waggle dances to study foraging locations of honey bees (Apis mellifera).
The aim of this work is to analyse if the honey bees use agricultural landscape in Burgos (Spain) to collect resources or they mostly forage at the wildflower resources. Moreover, to study if the temporal and spatial variation of resources in the landscape affects their foraging patterns. The waggle dance information was used as the main method of detecting the foraging locations used by the colony. Nectar, Pollen and in general Flower resource availability was also assessed at a landscape level, giving us the opportunity to find their distribution spatially.
Mari is defending her thesis at UC. She often collaborates with the B-team, a group of investigator from de Soil Ecology and Ecotoxicology Laboratory - Centre for Functional Ecology, which has the honey bee and another wild bees as study model.
Bichitra Paul is an IMAE student from Bangladesh. She is part of the 2017-2019 IMAE edition and she choose to continue at the University of Coimbra (UC) to work on her thesis project: Characterisation of the cytokinin mediated biocontrol activity of Chlamydomonas reinhardtii against Pseudomonas syringae in Tobacco.
The aim of the thesis is to prove that Microalgae which produce cytokinins can provide pathogen resistance to plants. This is done by comparing wild-type microalgae to its corresponding knockout mutants (which have certain genes of the cytokinin biosynthesis pathway deleted). The functional characterisation of this inter- organism phytohormone mediated interaction will help us understand the underlying molecular mechanism of this three way interaction between organisms.
Although Bichitra is defending her thesis at UC, she had the opportunity to carry out her work at the Molecular Plant Physiology and Phenomics laboratory at the Crop Sciences section in the University of Copenhagen, Denmark under the supervision of Dr. Thomas Georg Roitsch.