title: Trust and reputation in dynamic scientific communities

authors: Rana, Omer F.

subjects: computer science

abstract: The formation of collaboration networks (or communities) is an important latent effect in many computational science undertakings. Generally, collaboration networks bring together participants who wish to achieve some common goal or outcome (often over short time frames). Increasingly, scientific collaborations are becoming interdisciplinary, and scientists are working in informal collaborations to solve complex problems that require multiple types of skills. Such networks generally might consist of participants with complementary or similar skills, who might decide to collaborate to solve more efficiently a single large problem. We argue that, given the diverse skills that such collaborations involve, deciding which partners to cooperate with is both critical and difficult. Two particularly important factors in this process are trust and reputation.

text: Trust and reputation in dynamic scientific communities The formation of collaboration networks (or communities) is an important latent effect in many computational science undertakings. Generally, collaboration networks bring together participants who wish to achieve some common goal or outcome (often over short time frames). Increasingly, scientific collaborations are becoming interdisciplinary, and scientists are working in informal collaborations to solve complex problems that require multiple types of skills. Such networks generally might consist of participants with complementary or similar skills, who might decide to collaborate to solve more efficiently a single large problem. We argue that, given the diverse skills that such collaborations involve, deciding which partners to cooperate with is both critical and difficult. Two particularly important factors in this process are trust and reputation.

year: 2004

title: Hypsometric and geometric controls on hydrodynamics, tidal asymmetry, and sediment connectivity in shallow estuarine systems

authors: de Ruiter, Peter Jaap

subjects: Oceanography

abstract: Estuaries and tidal basins are highly dynamic coastal systems that serve as a transition zone between the river and the ocean. The morphological evolution of these diverse environments is modulated by non-linear feedbacks between tides, meteorological forcing, and sediment transport processes. This thesis focuses on the fundamental links between these physical processes, and the geomorphologic characteristics of shallow estuarine systems, specifically: (i) how shallow basin geometries and hypsometries affect hydrodynamics and tidal asymmetry, (ii) how wind-induced currents modify velocity asymmetry in shallow basins, and (iii) defining the relationships between geometry, hypsometry, and sediment connectivity inside shallow estuarine systems. 

Linking geomorphological characteristics and tidal processes in shallow tidal basins
The links between tidal basin geometry and hypsometry, bed shear stress patterns, tidal velocity- and slack water asymmetry, and hypsometric profile shapes were explored for six shallow microtidal basins of Tauranga Harbour, New Zealand. Model results, obtained from a depth-averaged numerical model developed in Delft3D for the full estuarine system, indicated that tidal distortion increases with distance from basin entrance. A simple ratio between tidal basin width and entrance width was defined to describe the planform shape of the basin. This metric, termed the ‘basin dilation factor’ indicates whether a basin can be designated as a divergent or convergent geometry. Shallow basins with a constricted geometry and relatively deep entrance channels were found to be associated with small bed shear stress values and high rates of flood-directed tidal velocity asymmetry in the sheltered basin centres. These results suggest substantial potential for sediment deposition of larger particles. Moreover, slack water asymmetry within these basins was weakly ebb-directed, indicating a small potential for export of fine sediments. These divergent, depositional basins were found to be characterized by convex hypsometric profiles with elevated intertidal regions. Conversely, unconstricted, convergent basins were associated with larger bed shear stress values and more ebb-directed tidal velocity asymmetry within basin centres. Consequently, there was limited potential for overall sediment deposition inside these basins. The slack water asymmetry was weakly flood-dominant, suggesting limited potential for fine sediment input. The comparatively high-energy conditions within these exposed tidal basins were associated with a less convex hypsometric intertidal profile. This study highlights the impacts of specific geomorphologic basin characteristics on tidal processes in shallow estuarine systems. The ability to predict the links between tidal asymmetry and morphological changes in tide-dominated systems is beneficial for coastal management, as the morphological evolution of estuarine systems affects coastal ecosystem functioning, port and estuary navigability, and potential for coastal protection. 

Understanding the effects of wind-driven currents on velocity asymmetry in shallow tidal basins
Numerical modelling experiments were conducted for a series of idealized basins in which planform shape and bathymetry were varied. The model results were used to examine how wind-generated currents modulate horizontal velocity asymmetry patterns in shallow tidal basins. This study revealed that wind-driven currents primarily influence mean and peak flow velocities inside the basins, with a limited effect on tidal harmonics. Faster wind speeds led to more extreme horizontal velocity asymmetry (larger velocity asymmetry values), without substantially modifying overall spatial patterns of velocity asymmetry. The velocity asymmetry was found to be strongly depth-dependent, with changes to asymmetry patterns being most evident for wind speeds of 6 m/s and greater, and for wind directions parallel to the main axes of the tidal channels in the basins. Shallow intertidal regions inside the basins were characterized by a downwind-directed increase in velocity asymmetry, whereas deeper subtidal channels experienced asymmetry changes in the opposite direction. Wind event duration and timing were also found to influence the velocity asymmetry patterns. The differences between the relative size of the peak flood- and ebb directed currents were most evident for wind events with a duration of 6 hours or less that coincide with flooding tides. The results of this study highlight that hydrodynamics, sediment transport, and morphological evolution in shallow estuaries are modulated by tidal processes as well as meteorological forcing. Since anthropogenically induced climate change is expected to increase the intensity of extreme meteorological events, the ability to predict future pathways of morphological change in shallow estuarine systems, based on specific meteorological conditions as well as well-defined local tidal regimes, is vital for the management of these dynamic systems. 

An examination of sediment connectivity in a shallow estuarine system
The sediment connectivity framework was used to examine links between hydrodynamics, sediment transport pathways, and local hypsometry inside a shallow estuarine system (Tauranga Harbour, New Zealand). The estuary was divided into twenty geomorphic cells, representing tidal channels, intertidal flats, and shallow sub-basins. Depth-averaged numerical modelling simulations were carried out to quantify tide-driven sediment connectivity between the cells for five sediment grainsize classes. Connectivity matrices were developed for the different grainsize classes, based on modelled sediment mass loads. Sediment connectivity inside the estuary was found to be modulated by tidal energy, estuarine morphology (depth), sub-basin hypsometry and geometry (planform shape), and sediment characteristics. The connectivity matrices, combined with metrics such as link density and cell strength, illustrated that sediment mass loads, and hence connectivity, were largest in the high-energy environments of the deep tidal channels located in the main estuary. In the more sheltered upper estuary, and inside the shallow sub-basins, connectivity was reduced. For fine sediments (< 125 μm) connectivity was found to be substantial throughout the shallow estuarine system, with estuary-level connectivity (link density) being greater than 50%. Link density for coarser sediments (> 275 μm) was found to be ~20%, with transport pathways primarily confined to the deeper regions of the estuary. An in-depth analysis of sediment transport pathways between the shallow sub-basins emphasized that flood-dominant, divergent basins with a convex-shaped hypsometric profile mainly function as sediment sinks, whereas ebb-dominant convergent basins act as sediment sources. 
This thesis highlights the substantial dependence of tidal asymmetry, morphology, sediment transport and connectivity on hypsometry, geometry, and grainsize characteristics inside shallow estuaries. Additionally, the effects of wind-driven currents on the non-linear physical processes inside these highly dynamic environments are described. Overall, this work provides a novel elucidation of some of the relationships between geometric parameters and forcing mechanisms applicable to many shallow coastal systems.

text: Hypsometric and geometric controls on hydrodynamics, tidal asymmetry, and sediment connectivity in shallow estuarine systems Estuaries and tidal basins are highly dynamic coastal systems that serve as a transition zone between the river and the ocean. The morphological evolution of these diverse environments is modulated by non-linear feedbacks between tides, meteorological forcing, and sediment transport processes. This thesis focuses on the fundamental links between these physical processes, and the geomorphologic characteristics of shallow estuarine systems, specifically: (i) how shallow basin geometries and hypsometries affect hydrodynamics and tidal asymmetry, (ii) how wind-induced currents modify velocity asymmetry in shallow basins, and (iii) defining the relationships between geometry, hypsometry, and sediment connectivity inside shallow estuarine systems. 

Linking geomorphological characteristics and tidal processes in shallow tidal basins
The links between tidal basin geometry and hypsometry, bed shear stress patterns, tidal velocity- and slack water asymmetry, and hypsometric profile shapes were explored for six shallow microtidal basins of Tauranga Harbour, New Zealand. Model results, obtained from a depth-averaged numerical model developed in Delft3D for the full estuarine system, indicated that tidal distortion increases with distance from basin entrance. A simple ratio between tidal basin width and entrance width was defined to describe the planform shape of the basin. This metric, termed the ‘basin dilation factor’ indicates whether a basin can be designated as a divergent or convergent geometry. Shallow basins with a constricted geometry and relatively deep entrance channels were found to be associated with small bed shear stress values and high rates of flood-directed tidal velocity asymmetry in the sheltered basin centres. These results suggest substantial potential for sediment deposition of larger particles. Moreover, slack water asymmetry within these basins was weakly ebb-directed, indicating a small potential for export of fine sediments. These divergent, depositional basins were found to be characterized by convex hypsometric profiles with elevated intertidal regions. Conversely, unconstricted, convergent basins were associated with larger bed shear stress values and more ebb-directed tidal velocity asymmetry within basin centres. Consequently, there was limited potential for overall sediment deposition inside these basins. The slack water asymmetry was weakly flood-dominant, suggesting limited potential for fine sediment input. The comparatively high-energy conditions within these exposed tidal basins were associated with a less convex hypsometric intertidal profile. This study highlights the impacts of specific geomorphologic basin characteristics on tidal processes in shallow estuarine systems. The ability to predict the links between tidal asymmetry and morphological changes in tide-dominated systems is beneficial for coastal management, as the morphological evolution of estuarine systems affects coastal ecosystem functioning, port and estuary navigability, and potential for coastal protection. 

Understanding the effects of wind-driven currents on velocity asymmetry in shallow tidal basins
Numerical modelling experiments were conducted for a series of idealized basins in which planform shape and bathymetry were varied. The model results were used to examine how wind-generated currents modulate horizontal velocity asymmetry patterns in shallow tidal basins. This study revealed that wind-driven currents primarily influence mean and peak flow velocities inside the basins, with a limited effect on tidal harmonics. Faster wind speeds led to more extreme horizontal velocity asymmetry (larger velocity asymmetry values), without substantially modifying overall spatial patterns of velocity asymmetry. The velocity asymmetry was found to be strongly depth-dependent, with changes to asymmetry patterns being most evident for wind speeds of 6 m/s and greater, and for wind directions parallel to the main axes of the tidal channels in the basins. Shallow intertidal regions inside the basins were characterized by a downwind-directed increase in velocity asymmetry, whereas deeper subtidal channels experienced asymmetry changes in the opposite direction. Wind event duration and timing were also found to influence the velocity asymmetry patterns. The differences between the relative size of the peak flood- and ebb directed currents were most evident for wind events with a duration of 6 hours or less that coincide with flooding tides. The results of this study highlight that hydrodynamics, sediment transport, and morphological evolution in shallow estuaries are modulated by tidal processes as well as meteorological forcing. Since anthropogenically induced climate change is expected to increase the intensity of extreme meteorological events, the ability to predict future pathways of morphological change in shallow estuarine systems, based on specific meteorological conditions as well as well-defined local tidal regimes, is vital for the management of these dynamic systems. 

An examination of sediment connectivity in a shallow estuarine system
The sediment connectivity framework was used to examine links between hydrodynamics, sediment transport pathways, and local hypsometry inside a shallow estuarine system (Tauranga Harbour, New Zealand). The estuary was divided into twenty geomorphic cells, representing tidal channels, intertidal flats, and shallow sub-basins. Depth-averaged numerical modelling simulations were carried out to quantify tide-driven sediment connectivity between the cells for five sediment grainsize classes. Connectivity matrices were developed for the different grainsize classes, based on modelled sediment mass loads. Sediment connectivity inside the estuary was found to be modulated by tidal energy, estuarine morphology (depth), sub-basin hypsometry and geometry (planform shape), and sediment characteristics. The connectivity matrices, combined with metrics such as link density and cell strength, illustrated that sediment mass loads, and hence connectivity, were largest in the high-energy environments of the deep tidal channels located in the main estuary. In the more sheltered upper estuary, and inside the shallow sub-basins, connectivity was reduced. For fine sediments (< 125 μm) connectivity was found to be substantial throughout the shallow estuarine system, with estuary-level connectivity (link density) being greater than 50%. Link density for coarser sediments (> 275 μm) was found to be ~20%, with transport pathways primarily confined to the deeper regions of the estuary. An in-depth analysis of sediment transport pathways between the shallow sub-basins emphasized that flood-dominant, divergent basins with a convex-shaped hypsometric profile mainly function as sediment sinks, whereas ebb-dominant convergent basins act as sediment sources. 
This thesis highlights the substantial dependence of tidal asymmetry, morphology, sediment transport and connectivity on hypsometry, geometry, and grainsize characteristics inside shallow estuaries. Additionally, the effects of wind-driven currents on the non-linear physical processes inside these highly dynamic environments are described. Overall, this work provides a novel elucidation of some of the relationships between geometric parameters and forcing mechanisms applicable to many shallow coastal systems.

year: 2022

title: Mouri Tu, Mouri Moko, Mouri Ora! Moko as a wellbeing strategy

authors: Penehira, Mera

subjects: Maori

abstract: This research has been undertaken within the Health Research Council funded International Collaborative Indigenous Health Research Partnership (ICIHRP) program, “The role of resiliency in responding to blood borne viral and sexually transmitted infections in Indigenous communities”. Some Indigenous communities in Australia, New Zealand and Canada have been shown to experience higher rates of blood borne viral infections. There are a number of categories of health intervention that have been shown to be effective in prevention and enhancing access to treatment for blood borne viral infections, including various forms of health promotion, enhanced diagnostic and treatment services, and harm reduction measures related to injecting drug use. The present research was undertaken with the understanding that development of effective responses of this kind among Indigenous people would benefit from a better understanding of the social and cultural factors that might protect against these infections and their consequences. It is argued that such factors are linked in various ways to Indigenous resistance and resiliency, which is described as the means by which people choose to make use of individual and community strengths to protect themselves against adverse health outcomes and enhance their health and wellbeing.

In this thesis I explore how people and their identity are affected when you are part of a marginalised or vulnerable population – namely, Māori women who have contracted the Hepatitis C Virus (HCV). I argue that traditional knowledge and healing practices are central to Māori getting well and keeping well, and that the use of cultural frameworks and practices have potentially restorative, therapeutic and healing values that are not yet researched or understood by the health field. I argue that a Māori framework of wellbeing, namely ‘Mana Kaitiakitanga’, provides the context in which tā moko (Māori traditional tattoo) fits naturally as a healing intervention. I share the stories of Māori women with HCV who have applied this (tā moko and other forms of tattoo) in their lives and in their journeys back to wellness. Tā moko is a process that penetrates the flesh and marks the skin; it is a process that involves both blood and pain, which may seem incongruous with healing. It is argued however that through pain comes understanding; through pain comes a RE-membering of strength; through pain comes joy; and finally through marking comes identity of who we are and how well we have been and can be again.

Issues and intersections of identity, marginalisation, gender, health, and wellbeing are at the forefront of this research story and of the journeys of the three women whose case studies are presented in this thesis. What makes this thesis unique is that it researches all three of these potential cornerstones of health: identity; wellbeing (spiritual and emotional), and physical wellbeing, in relation to a specific health problem, namely HCV. It is intended that this work will add power to what might be viewed as a particularly Indigenous solution to a virus that disproportionately affects our Indigenous population. This is not about rejecting Western health solutions, but it is about recognising and returning to Indigenous health solutions.

text: Mouri Tu, Mouri Moko, Mouri Ora! Moko as a wellbeing strategy This research has been undertaken within the Health Research Council funded International Collaborative Indigenous Health Research Partnership (ICIHRP) program, “The role of resiliency in responding to blood borne viral and sexually transmitted infections in Indigenous communities”. Some Indigenous communities in Australia, New Zealand and Canada have been shown to experience higher rates of blood borne viral infections. There are a number of categories of health intervention that have been shown to be effective in prevention and enhancing access to treatment for blood borne viral infections, including various forms of health promotion, enhanced diagnostic and treatment services, and harm reduction measures related to injecting drug use. The present research was undertaken with the understanding that development of effective responses of this kind among Indigenous people would benefit from a better understanding of the social and cultural factors that might protect against these infections and their consequences. It is argued that such factors are linked in various ways to Indigenous resistance and resiliency, which is described as the means by which people choose to make use of individual and community strengths to protect themselves against adverse health outcomes and enhance their health and wellbeing.

In this thesis I explore how people and their identity are affected when you are part of a marginalised or vulnerable population – namely, Māori women who have contracted the Hepatitis C Virus (HCV). I argue that traditional knowledge and healing practices are central to Māori getting well and keeping well, and that the use of cultural frameworks and practices have potentially restorative, therapeutic and healing values that are not yet researched or understood by the health field. I argue that a Māori framework of wellbeing, namely ‘Mana Kaitiakitanga’, provides the context in which tā moko (Māori traditional tattoo) fits naturally as a healing intervention. I share the stories of Māori women with HCV who have applied this (tā moko and other forms of tattoo) in their lives and in their journeys back to wellness. Tā moko is a process that penetrates the flesh and marks the skin; it is a process that involves both blood and pain, which may seem incongruous with healing. It is argued however that through pain comes understanding; through pain comes a RE-membering of strength; through pain comes joy; and finally through marking comes identity of who we are and how well we have been and can be again.

Issues and intersections of identity, marginalisation, gender, health, and wellbeing are at the forefront of this research story and of the journeys of the three women whose case studies are presented in this thesis. What makes this thesis unique is that it researches all three of these potential cornerstones of health: identity; wellbeing (spiritual and emotional), and physical wellbeing, in relation to a specific health problem, namely HCV. It is intended that this work will add power to what might be viewed as a particularly Indigenous solution to a virus that disproportionately affects our Indigenous population. This is not about rejecting Western health solutions, but it is about recognising and returning to Indigenous health solutions.

year: 2011