title: Marks of conscious engagement when performing a motor task with or without a robotic arm

authors: Wright, Madison

subjects: conscious control

abstract: Utilizing prosthetic limbs effectively and alleviating the conscious burden through
minimizing conscious control is important to address and understand in the ever-changing
world of technology. Prosthetics can be difficult to learn how to use effectively and using them
increases conscious awareness which is termed a burden. The conscious burden prosthetics
have on users is consistently addressed by a multitude of studies and garners for more in depth
research to understand and identify solutions to alleviate this burden. Conscious motor control
is defined as the level of awareness of an individual performing a movement related skill or
task, where the higher the conscious control the more an individual is thinking of their
movements while executing them. The aim of this thesis was to measure conscious burden
objectively by examining the marks of conscious engagement when performing a reaction time
task with and without a robotic arm.

Chapter 1 is an introduction to this thesis including a literature review of relevant topics
such as prosthetic limbs, conscious movement control, subjective and objective measurements
of conscious movement control and electroencephalography (EEG). Prosthetic rejection rates,
conscious burden and prosthetic limb learning are also addressed. The outline of the experiment
for this thesis is included and discussed more in depth in Chapter 2.

Chapter 2 is the experiment in full examining the level of conscious control while
participating in a reaction time based motor learning task using a robotic arm versus own arm.
There were two conditions, the complex condition (multi-choice) and simple condition (single
choice). A secondary task of tone counting was included in half the trials to examine whether
more conscious processing is involved when working with the robotic arm versus normal arm
while doing the reaction time task. It was expected that there would be higher conscious control
and slower reaction times when participants used the robotic arm compared to their own arm.

EEG was used to assess the connectivity between the left temporal verbal-analytical (T7) site
and the motor planning mid-frontal (Fz) site of the brain. Connectivity of T7-Fz is used to
measure the verbal-analytical engagement in motor planning which is then used to measure
conscious control. The results revealed the complex condition had a significantly higher
reaction time dual-task cost for arm compared to robotic arm and a higher T7-Fz connectivity
dual-cost (difference in performance for single versus dual task) for the robotic arm in the
complex condition compared to simple condition. We concluded that use of a robotic arm
increases verbal-analytical engagement when performing a motor task compared to using the
own arm.

Chapter 3 is the overall discussion of the experimental findings for the use of robotic
arms in reaction time tasks measuring conscious control and what it may mean for future
research. Implicit motor learning is discussed as well as implicit motor learning interventions
such as dual-task learning, analogy learning and errorless learning. There are also other
learning interventions to promote intuitive control in prosthetic limb learning such as gaze
training and neurofeedback.

text: Marks of conscious engagement when performing a motor task with or without a robotic arm Utilizing prosthetic limbs effectively and alleviating the conscious burden through
minimizing conscious control is important to address and understand in the ever-changing
world of technology. Prosthetics can be difficult to learn how to use effectively and using them
increases conscious awareness which is termed a burden. The conscious burden prosthetics
have on users is consistently addressed by a multitude of studies and garners for more in depth
research to understand and identify solutions to alleviate this burden. Conscious motor control
is defined as the level of awareness of an individual performing a movement related skill or
task, where the higher the conscious control the more an individual is thinking of their
movements while executing them. The aim of this thesis was to measure conscious burden
objectively by examining the marks of conscious engagement when performing a reaction time
task with and without a robotic arm.

Chapter 1 is an introduction to this thesis including a literature review of relevant topics
such as prosthetic limbs, conscious movement control, subjective and objective measurements
of conscious movement control and electroencephalography (EEG). Prosthetic rejection rates,
conscious burden and prosthetic limb learning are also addressed. The outline of the experiment
for this thesis is included and discussed more in depth in Chapter 2.

Chapter 2 is the experiment in full examining the level of conscious control while
participating in a reaction time based motor learning task using a robotic arm versus own arm.
There were two conditions, the complex condition (multi-choice) and simple condition (single
choice). A secondary task of tone counting was included in half the trials to examine whether
more conscious processing is involved when working with the robotic arm versus normal arm
while doing the reaction time task. It was expected that there would be higher conscious control
and slower reaction times when participants used the robotic arm compared to their own arm.

EEG was used to assess the connectivity between the left temporal verbal-analytical (T7) site
and the motor planning mid-frontal (Fz) site of the brain. Connectivity of T7-Fz is used to
measure the verbal-analytical engagement in motor planning which is then used to measure
conscious control. The results revealed the complex condition had a significantly higher
reaction time dual-task cost for arm compared to robotic arm and a higher T7-Fz connectivity
dual-cost (difference in performance for single versus dual task) for the robotic arm in the
complex condition compared to simple condition. We concluded that use of a robotic arm
increases verbal-analytical engagement when performing a motor task compared to using the
own arm.

Chapter 3 is the overall discussion of the experimental findings for the use of robotic
arms in reaction time tasks measuring conscious control and what it may mean for future
research. Implicit motor learning is discussed as well as implicit motor learning interventions
such as dual-task learning, analogy learning and errorless learning. There are also other
learning interventions to promote intuitive control in prosthetic limb learning such as gaze
training and neurofeedback.

year: 2024

title: Development of biomaterials from sustainably produced macroalgae feedstocks

authors: Jayasooriya, Nethmie

subjects: cellulose

abstract: Upgrading and maintaining large-scale wastewater treatment plants (WWTPs) is notably expensive, particularly in rural areas of New Zealand. Freshwater macroalgae ponds may offer a cost-effective alternative for wastewater treatment in these areas. These ponds produce significant amounts of residual macroalgae biomass as a by-product of the bioremediation process, which is nutrient-rich and contains valuable biopolymers like cellulose. Utilizing this residual biomass as a substrate for high-value cellulose production is yet to be demonstrated. Therefore, this thesis investigated the potential of utilizing this residual freshwater macroalgae biomass to develop bioproducts (cellulose and biostimulants) aligning with the principles of a circular economy and waste recovery.

The first chapter investigated the dual extraction process of biostimulants and high-purity cellulose from Oedogonium calcareum grown in primary effluent. It introduces an economical and effective extraction method utilizing a hot alkali, which also provides disinfection, ensuring that the biomass is free from pathogens, making it safe for further use. The biostimulant extract was found to be comprised of several plant-promoting substances. Subsequently, the residual biomass was used to extract cellulose, and the quality of this Oedogonium-derived cellulose was assessed to determine its characteristics for potential future use in biocomposites.

In the second chapter, a comparative analysis was conducted on cellulose extracted from four macroalgae species, namely Rhizoclonium sp., Zygnema sp., Oedogonium sp., and Stigeoclonium sp. This research filled a significant gap by providing a detailed characterization of cellulose derived from freshwater macroalgae, which has been less studied compared to cellulose from marine macroalgae. This chapter makes a significant contribution by fully characterizing the physicochemical properties of freshwater macroalgae cellulose, which as a by-product of wastewater treatment, provides an alternative and sustainable source of cellulose with potential future applications in biocomposites.

The final chapter details the development of biocomposite films using poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) reinforced with cellulose nanofibers derived from a naturally co-existing mixed algae culture of Cladophora sp. and Rhizoclonium sp. The production and characterization of 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO)-oxidized Cellulose NanoFibre (CNF) from these macroalgae was accessed. Additionally, PHBV polymer biocomposite films incorporating either commercially available plant-derived CNF, unmodified algae cellulose, or TEMPO-oxidized CNF were compared. The films were comprehensively characterized, with a focus on their mechanical and thermal properties. The results demonstrated the potential of these biocomposite films for use in applications such as packaging materials, highlighting their environmental and functional benefits.

Overall, this thesis demonstrates significant advancements in the utilization of algae grown in wastewater for the successful extraction of bioproducts. It investigated the efficient recovery and application of macroalgae-derived cellulose and also highlighted the potential of these bio-based materials in enhancing the properties of the PHBV polymer, thus contributing to the development of sustainable biocomposite materials.

text: Development of biomaterials from sustainably produced macroalgae feedstocks Upgrading and maintaining large-scale wastewater treatment plants (WWTPs) is notably expensive, particularly in rural areas of New Zealand. Freshwater macroalgae ponds may offer a cost-effective alternative for wastewater treatment in these areas. These ponds produce significant amounts of residual macroalgae biomass as a by-product of the bioremediation process, which is nutrient-rich and contains valuable biopolymers like cellulose. Utilizing this residual biomass as a substrate for high-value cellulose production is yet to be demonstrated. Therefore, this thesis investigated the potential of utilizing this residual freshwater macroalgae biomass to develop bioproducts (cellulose and biostimulants) aligning with the principles of a circular economy and waste recovery.

The first chapter investigated the dual extraction process of biostimulants and high-purity cellulose from Oedogonium calcareum grown in primary effluent. It introduces an economical and effective extraction method utilizing a hot alkali, which also provides disinfection, ensuring that the biomass is free from pathogens, making it safe for further use. The biostimulant extract was found to be comprised of several plant-promoting substances. Subsequently, the residual biomass was used to extract cellulose, and the quality of this Oedogonium-derived cellulose was assessed to determine its characteristics for potential future use in biocomposites.

In the second chapter, a comparative analysis was conducted on cellulose extracted from four macroalgae species, namely Rhizoclonium sp., Zygnema sp., Oedogonium sp., and Stigeoclonium sp. This research filled a significant gap by providing a detailed characterization of cellulose derived from freshwater macroalgae, which has been less studied compared to cellulose from marine macroalgae. This chapter makes a significant contribution by fully characterizing the physicochemical properties of freshwater macroalgae cellulose, which as a by-product of wastewater treatment, provides an alternative and sustainable source of cellulose with potential future applications in biocomposites.

The final chapter details the development of biocomposite films using poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) reinforced with cellulose nanofibers derived from a naturally co-existing mixed algae culture of Cladophora sp. and Rhizoclonium sp. The production and characterization of 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO)-oxidized Cellulose NanoFibre (CNF) from these macroalgae was accessed. Additionally, PHBV polymer biocomposite films incorporating either commercially available plant-derived CNF, unmodified algae cellulose, or TEMPO-oxidized CNF were compared. The films were comprehensively characterized, with a focus on their mechanical and thermal properties. The results demonstrated the potential of these biocomposite films for use in applications such as packaging materials, highlighting their environmental and functional benefits.

Overall, this thesis demonstrates significant advancements in the utilization of algae grown in wastewater for the successful extraction of bioproducts. It investigated the efficient recovery and application of macroalgae-derived cellulose and also highlighted the potential of these bio-based materials in enhancing the properties of the PHBV polymer, thus contributing to the development of sustainable biocomposite materials.

year: 2024-07-17

title: Comparative fish abundance in the shallow Waikato lakes Whangape and Hakanoa

authors: Hicks, Brendan J.

abstract: The Waikato-Tainui College for Research and Development contracted the University of Waikato to conduct boat electrofishing estimates of the fish abundance in lakes Whangape and Hakanoa; both are shallow, riverine lakes in the lower Waikato River floodplain and are about 2,000 years old. Lake Whangape (latitude 37.46853°S, longitude 175.05120°W) is a large (1,450 ha), shallow (maximum depth 2.7 m) lake to the west of the Waikato River; Lake Hakanoa (latitude 37.55258°S, longitude 175.16859°W) is a 52-ha lake in suburban Huntly with a maximum depth of 2.5 m.
We fished 10 sites for 10 mins in both lakes Whangape and Lake Hakanoa; sites fished were 253-609 m long (1,012-2,436 m² in area) in Lake Whangape and 125-276 m long (500-1,104 m² in area) in Lake Hakanoa.
No submerged aquatic macrophytes were seen in either lake. Fishing was conducted close to the water's edge in Lake Hakanoa, but the shallow margins in Lake Whangape restricted fishing at most sites to 30-70 m from the shoreline. The shoreline was much more accessible in Lake Hakanoa, and was dominated by raupo (Typha orientalis) with willows (Salix spp.) in places. Submerged tree trunks and logs in Lake Hakanoa made navigation difficult in parts of the lake margins.
We caught a total of 118 fish in Lake Whangape, where shortfin eels (Anguilla australis) were the most abundant fish, and 594 fish in Lake Hakanoa, where gambusia (Gambusia affinis) the most abundant species. In Lake Whangape, shortfin eels comprised the greatest total biomass (12.4 kg), with koi carp (Cyprinus carpio) almost equally abundant (11.4 kg). In Lake Hakanoa, koi carp were most abundant (74.4 kg), followed by shortfin eels (22.1 kg).
Fish were unevenly spread among sites in Lake Whangape and koi carp were relatively sparsely among sites. In Lake Hakanoa, in contrast, fish were more evenly spread among sites, but with higher concentrations of catfish (Ameiurus nebulosus) and goldfish (Carassius auratus) at a few sites. Biomass of fish caught in each of the ten 10-min fishing shots reflected the numerical distributions, with some wide variations between sites. Fish densities were generally lower in Lake Whangape than in Lake Hakanoa; however, common smelt (Retropinna retropinna) and grey mullet (Mugil cephalus) occurred in Whangape but not in Hakanoa. Areal fish biomass was dominated by shortfin eels and koi carp in Lake Whangape, but koi carp dominated the fish biomass in Lake Hakanoa, despite the smaller number of carp than eels. This was because of the large mean weight of koi carp (about 1,000 g) compared to the smaller shortfin eels (mean weight about 200 g in both lakes).

text: Comparative fish abundance in the shallow Waikato lakes Whangape and Hakanoa The Waikato-Tainui College for Research and Development contracted the University of Waikato to conduct boat electrofishing estimates of the fish abundance in lakes Whangape and Hakanoa; both are shallow, riverine lakes in the lower Waikato River floodplain and are about 2,000 years old. Lake Whangape (latitude 37.46853°S, longitude 175.05120°W) is a large (1,450 ha), shallow (maximum depth 2.7 m) lake to the west of the Waikato River; Lake Hakanoa (latitude 37.55258°S, longitude 175.16859°W) is a 52-ha lake in suburban Huntly with a maximum depth of 2.5 m.
We fished 10 sites for 10 mins in both lakes Whangape and Lake Hakanoa; sites fished were 253-609 m long (1,012-2,436 m² in area) in Lake Whangape and 125-276 m long (500-1,104 m² in area) in Lake Hakanoa.
No submerged aquatic macrophytes were seen in either lake. Fishing was conducted close to the water's edge in Lake Hakanoa, but the shallow margins in Lake Whangape restricted fishing at most sites to 30-70 m from the shoreline. The shoreline was much more accessible in Lake Hakanoa, and was dominated by raupo (Typha orientalis) with willows (Salix spp.) in places. Submerged tree trunks and logs in Lake Hakanoa made navigation difficult in parts of the lake margins.
We caught a total of 118 fish in Lake Whangape, where shortfin eels (Anguilla australis) were the most abundant fish, and 594 fish in Lake Hakanoa, where gambusia (Gambusia affinis) the most abundant species. In Lake Whangape, shortfin eels comprised the greatest total biomass (12.4 kg), with koi carp (Cyprinus carpio) almost equally abundant (11.4 kg). In Lake Hakanoa, koi carp were most abundant (74.4 kg), followed by shortfin eels (22.1 kg).
Fish were unevenly spread among sites in Lake Whangape and koi carp were relatively sparsely among sites. In Lake Hakanoa, in contrast, fish were more evenly spread among sites, but with higher concentrations of catfish (Ameiurus nebulosus) and goldfish (Carassius auratus) at a few sites. Biomass of fish caught in each of the ten 10-min fishing shots reflected the numerical distributions, with some wide variations between sites. Fish densities were generally lower in Lake Whangape than in Lake Hakanoa; however, common smelt (Retropinna retropinna) and grey mullet (Mugil cephalus) occurred in Whangape but not in Hakanoa. Areal fish biomass was dominated by shortfin eels and koi carp in Lake Whangape, but koi carp dominated the fish biomass in Lake Hakanoa, despite the smaller number of carp than eels. This was because of the large mean weight of koi carp (about 1,000 g) compared to the smaller shortfin eels (mean weight about 200 g in both lakes).

year: 2016