title: Spatial variation in functional group diversity in a sandflat benthic community: implications for ecosystem resilience

authors: Greenfield, Barry Leon

abstract: The resilience of macrobenthic communities to environmental stress depends upon the vulnerability, adaptability and connectivity of species. Recent studies suggest that the function(s) species perform may be more influential in driving community response to change than the more traditional measures of abundance and occurrence. Species that perform similar functions within a community theoretically give rise to redundancy, an important attribute of resilience. This thesis assesses the potential for functional redundancy in coastal macrobenthic communities by comparing the degree of sharing of specific functional traits, patterns of abundance and spatial distribution to provide insight into the potential for resilience. The research is focused on the functional diversity of a species rich macrobenthic community from a large intertidal area in the Kaipara Harbour, New Zealand. 400 macrofaunal and 360 sediment cores were collected using a newly developed hierarchical sampling grid covering an area of 300,000 m². This resulted in a data set consisting of 115 taxa and 23,682 individuals and 360 observations of sediment grain size and chlorophyll a. Linking species attributes such as body type, size, feeding mode, and living depth, produced 26 species functional groups that characterised important functional attributes of the macrobenthic community. These attributes relate to ecosystem functions associated with sediment biogeochemistry, stability and resilience to disturbance. Redundancy was assessed within these functional groups (ranging from 1-13 species per functional group) considering both occurrence and abundance in their spatial distribution. Various levels of redundancy were identified for different functional groups, for example, functional groups characterised by small deposit-feeding polychaetes encompassed high redundancy, whilst functional groups consisting of large suspension-feeding, highly mobile bivalves maintained low redundancy. Nevertheless, the latter functional group does contribute considerably to abundance despite its low redundancy. The spatial patterns exhibited by different functional groups (identified by correlograms using Moran’s I) were used to provide insights to connectivity and exposure of the functional group to localised disturbance.  A range of spatial patterns were apparent, reflecting small-scale homogeneity to large-scale heterogeneity with spatial arrangements including gradients and distinct patches. Density maps showed that some functional groups, such as tube worms and large mobile suspension-feeding bivalves, showed strong and opposing spatial distributions, separated by clear boundaries. Canonical correspondence analyses indicated that the measured environmental variables were not important drivers of the spatial distribution of functional groups. Thus, either biological interactions between functional groups are the driving force of spatial diversity or this sampling strategy failed to measure relevant environmental parameters. These findings emphasise a role for spatial variation in functional diversity and species redundancy in structuring community resilience. Understanding the functional roles of species, the diversity of these functions and associated biological interactions, is essential for evaluating biodiversity and resilience.

text: Spatial variation in functional group diversity in a sandflat benthic community: implications for ecosystem resilience The resilience of macrobenthic communities to environmental stress depends upon the vulnerability, adaptability and connectivity of species. Recent studies suggest that the function(s) species perform may be more influential in driving community response to change than the more traditional measures of abundance and occurrence. Species that perform similar functions within a community theoretically give rise to redundancy, an important attribute of resilience. This thesis assesses the potential for functional redundancy in coastal macrobenthic communities by comparing the degree of sharing of specific functional traits, patterns of abundance and spatial distribution to provide insight into the potential for resilience. The research is focused on the functional diversity of a species rich macrobenthic community from a large intertidal area in the Kaipara Harbour, New Zealand. 400 macrofaunal and 360 sediment cores were collected using a newly developed hierarchical sampling grid covering an area of 300,000 m². This resulted in a data set consisting of 115 taxa and 23,682 individuals and 360 observations of sediment grain size and chlorophyll a. Linking species attributes such as body type, size, feeding mode, and living depth, produced 26 species functional groups that characterised important functional attributes of the macrobenthic community. These attributes relate to ecosystem functions associated with sediment biogeochemistry, stability and resilience to disturbance. Redundancy was assessed within these functional groups (ranging from 1-13 species per functional group) considering both occurrence and abundance in their spatial distribution. Various levels of redundancy were identified for different functional groups, for example, functional groups characterised by small deposit-feeding polychaetes encompassed high redundancy, whilst functional groups consisting of large suspension-feeding, highly mobile bivalves maintained low redundancy. Nevertheless, the latter functional group does contribute considerably to abundance despite its low redundancy. The spatial patterns exhibited by different functional groups (identified by correlograms using Moran’s I) were used to provide insights to connectivity and exposure of the functional group to localised disturbance.  A range of spatial patterns were apparent, reflecting small-scale homogeneity to large-scale heterogeneity with spatial arrangements including gradients and distinct patches. Density maps showed that some functional groups, such as tube worms and large mobile suspension-feeding bivalves, showed strong and opposing spatial distributions, separated by clear boundaries. Canonical correspondence analyses indicated that the measured environmental variables were not important drivers of the spatial distribution of functional groups. Thus, either biological interactions between functional groups are the driving force of spatial diversity or this sampling strategy failed to measure relevant environmental parameters. These findings emphasise a role for spatial variation in functional diversity and species redundancy in structuring community resilience. Understanding the functional roles of species, the diversity of these functions and associated biological interactions, is essential for evaluating biodiversity and resilience.

year: 2013

title: Biosensing by Learning: Cancer Detection as Iterative optimization.

authors: Chen, Yifan

subjects: Algorithms

abstract: We propose a novel cancer detection procedure (CDP) based on an iterative optimization method. The global minimum of a tumor-induced biological cost function indicates the tumor location, the domain of the cost function is the tissue region at high risk of malignancy, and the time-variant guess input is a swarm of externally controllable and trackable nanorobots for tumor sensing. We consider the spatial distrib-ution of fibrin as the cost function; the fibrin is formed during the coagulation cascade activated by tumor-targeted signalling modules (nanoparticles) and recruits clot-targeted receiving modules (nanorobots) towards the site of disease. Subsequently, the CDP can be interpreted from the iterative optimization perspective: the guess input (i.e., a swarm of nanorobots) is continuously updated according to the gradient of the cost function in order to find the optimum (i.e., cancer) by moving through the domain (i.e., tissue under screening). Along this line of thought, we consider the gradient descent (GD) iterative method, and propose the GD-inspired CDP, which takes into account the realistic in vivo propagation scenario of nanorobots. Finally, we present numerical examples to demonstrate the features of the GD-inspired CDP.

text: Biosensing by Learning: Cancer Detection as Iterative optimization. We propose a novel cancer detection procedure (CDP) based on an iterative optimization method. The global minimum of a tumor-induced biological cost function indicates the tumor location, the domain of the cost function is the tissue region at high risk of malignancy, and the time-variant guess input is a swarm of externally controllable and trackable nanorobots for tumor sensing. We consider the spatial distrib-ution of fibrin as the cost function; the fibrin is formed during the coagulation cascade activated by tumor-targeted signalling modules (nanoparticles) and recruits clot-targeted receiving modules (nanorobots) towards the site of disease. Subsequently, the CDP can be interpreted from the iterative optimization perspective: the guess input (i.e., a swarm of nanorobots) is continuously updated according to the gradient of the cost function in order to find the optimum (i.e., cancer) by moving through the domain (i.e., tissue under screening). Along this line of thought, we consider the gradient descent (GD) iterative method, and propose the GD-inspired CDP, which takes into account the realistic in vivo propagation scenario of nanorobots. Finally, we present numerical examples to demonstrate the features of the GD-inspired CDP.

year: 2018

title: Te Whakaruruhau Transition and Wellbeing programme: An implementation evaluation

authors: Robins, Kathryn

subjects: Maori

abstract: Based on the recognition that many women who come into refuge have few options
but to return to the sort of environment in which they have been abused, the
Transition and Wellbeing programme aims to provide medium to long term housing
for families as they re‐establish themselves in the community.
Data for the evaluation of the programme was collected from two main sources; the
women on the programme and key informants at Te Whakaruruhau. Five women,
two of whom are housed in transitional accommodation were interviewed
individually, while focus groups were conducted with middle and senior management
teams.
The completion of the interviews enabled the development of a programme logic,
which describes the ‘theory’ of the programme. The model details the activities or
what the programme does. These activities include linking women to programmes
and resources, providing practical support, addressing specific cultural needs and the
availability of quality advocates. These activities are built on foundational values, such
as, whanaungatanga, manaakitanga and wairuatanga. The programme is only made
possible with internal and external inputs. Of the external inputs, funding
contributions are considered vital to the functioning of the programme.
The women’s perspectives identified varying outcomes from their participation in the
programme. The logic model details the intended outcomes in the short, medium and
long‐term, reflecting personal, relational and community wellbeing. Short term
outcomes include improved communication, improved self‐esteem, improved
confidence and personal growth. Medium outcomes saw (re)engagement in training,
education and for some, (re)entry into the workforce. Long term outcomes related to
the establishment of a sustainable life style free from violence.
The participants did not see a need to modify the programme in any significant way.
Some did think that it could be usefully extended by adding to the existing activities a
hands on, artistic approach. Programme developers may consider more creative ways
in which to assess and measure the impact of the programme. Finally, it is suggested
that the programme could benefit from a more systemic assessment process to
determine whether women are “ready” to enter it.

text: Te Whakaruruhau Transition and Wellbeing programme: An implementation evaluation Based on the recognition that many women who come into refuge have few options
but to return to the sort of environment in which they have been abused, the
Transition and Wellbeing programme aims to provide medium to long term housing
for families as they re‐establish themselves in the community.
Data for the evaluation of the programme was collected from two main sources; the
women on the programme and key informants at Te Whakaruruhau. Five women,
two of whom are housed in transitional accommodation were interviewed
individually, while focus groups were conducted with middle and senior management
teams.
The completion of the interviews enabled the development of a programme logic,
which describes the ‘theory’ of the programme. The model details the activities or
what the programme does. These activities include linking women to programmes
and resources, providing practical support, addressing specific cultural needs and the
availability of quality advocates. These activities are built on foundational values, such
as, whanaungatanga, manaakitanga and wairuatanga. The programme is only made
possible with internal and external inputs. Of the external inputs, funding
contributions are considered vital to the functioning of the programme.
The women’s perspectives identified varying outcomes from their participation in the
programme. The logic model details the intended outcomes in the short, medium and
long‐term, reflecting personal, relational and community wellbeing. Short term
outcomes include improved communication, improved self‐esteem, improved
confidence and personal growth. Medium outcomes saw (re)engagement in training,
education and for some, (re)entry into the workforce. Long term outcomes related to
the establishment of a sustainable life style free from violence.
The participants did not see a need to modify the programme in any significant way.
Some did think that it could be usefully extended by adding to the existing activities a
hands on, artistic approach. Programme developers may consider more creative ways
in which to assess and measure the impact of the programme. Finally, it is suggested
that the programme could benefit from a more systemic assessment process to
determine whether women are “ready” to enter it.

year: 2008-06-26