title: Virtual numbers for virtual machines?

authors: Tan, Alan Y.S.

subjects: cloud computing

abstract: Knowing the number of virtual machines (VMs) that a cloud physical hardware can (further) support is critical as it has implications on provisioning and hardware procurement. However, current methods for estimating the maximum number of VMs possible on a given hardware is usually the ratio of the specifications of a VM to the underlying cloud hardware’s specifications. Such naive and linear estimation methods mostly yield impractical limits as to how many VMs the hardware can actually support. It was found that if we base on the naive division method, user experience on VMs at those limits would be severely degraded. In this paper, we demonstrate through experimental results, the significant gap between the limits derived using the estimation method mentioned above and the actual situation. We believe for a more practicable estimation of the limits of the underlying infrastructure,

text: Virtual numbers for virtual machines? Knowing the number of virtual machines (VMs) that a cloud physical hardware can (further) support is critical as it has implications on provisioning and hardware procurement. However, current methods for estimating the maximum number of VMs possible on a given hardware is usually the ratio of the specifications of a VM to the underlying cloud hardware’s specifications. Such naive and linear estimation methods mostly yield impractical limits as to how many VMs the hardware can actually support. It was found that if we base on the naive division method, user experience on VMs at those limits would be severely degraded. In this paper, we demonstrate through experimental results, the significant gap between the limits derived using the estimation method mentioned above and the actual situation. We believe for a more practicable estimation of the limits of the underlying infrastructure,

year: 2014

title: Effects of macrofauna diversity on porewater nutrient concentrations following enrichment

authors: Hines, Laura Veronica

subjects: Macrofauna diversity

abstract: Macrofauna play a key role in the functioning of soft sediment intertidal ecosystems via bioturbation and feeding habits which modify sediment biogeochemistry and influence nutrient cycling. Eutrophication is a naturally occurring phenomenon; however, enrichment due to anthropogenic inputs has increased in frequency with largely unknown consequences to benthic macrofaunal assemblages. A decline in infaunal biodiversity is thought to result in the loss of ecosystem function due to increased disturbance in the form of enhanced nutrient addition. This is increasingly important to estuarine habitats, as benthic macrofauna play an important role in controlling sediment porewater nutrient concentrations, nutrient flux to the overlying water column and ultimately ecosystem function. Sediment modification by macrofauna behaviours (e.g. bioturbation) stimulate nutrient regeneration and influence denitrification rate. Thus understanding the responses of macrofauna to enhanced nutrient levels is vital for the understanding and subsequent management of benthic assemblages to estuarine eutrophication. The aim of this thesis was to stress the intertidal sediment of the Kaipara Harbour by the addition of slow-release fertiliser in order to identify key macrofaunal diversity responses and the influence this has in the overall nutrient processing ability. I also examined whether fertiliser addition influenced primary producers, microphytobenthos biomass and the percent coverage of seagrass. 

To gain a better understanding of porewater nutrient elevation and subsequent impacts to macrofaunal diversity, 28 site locations were selected based on high and low functional macrofaunal diversity and abundance characteristics previously identified within Tapora Bank, Kaipara Harbour (Greenfield 2013). Known amounts (1400g m⁻² (high treatment) and 600g m⁻² (medium treatment)) of 70-day slow-release fertiliser (42 % N) was added to the intertidal sediment across a gradient in macrofaunal diversity. Porewater and sediment properties were measured 28 and 47 days after enrichment, with macrofaunal diversity determined on day 47.

The fertiliser enriched plots significantly elevated porewater ammonium concentrations in both treatments in upper (0-2 cm) and lower (5-7 cm) sediment depths. Lower sampling depths had greater concentrations of porewater ammonium than the upper sediments. This elevation resulted a decline in the overall macrofaunal abundance in both addition treatments however, only the decline in key functional species Macomona liliana was significant. The number of functional individuals and number of M. liliana were identified as significant factors controlling the variation in porewater ammonium concentration in ambient sediments. A switch was observed after fertiliser elevation where mud become the sole driver of porewater ammonium concentration in plots of high fertiliser addition. Normalisation treatment porewater ammonium concentration by the control plot values identified both the number of species and number of functional species as important drivers of porewater ammonium processing. No effect of fertiliser enrichment to seagrass percent coverage was observed. 

These results demonstrate that the elevation of porewater ammonium within intertidal sediments may have implications to the diversity and the subsequent functioning of intertidal benthic communities. In particularly, our study highlights the potential loss of functioning related to the decline of key species such as M. liliana; given their role as ecosystem engineers, their loss could reinforce the effects of eutrophication stress on the system and lead to further degradation.

text: Effects of macrofauna diversity on porewater nutrient concentrations following enrichment Macrofauna play a key role in the functioning of soft sediment intertidal ecosystems via bioturbation and feeding habits which modify sediment biogeochemistry and influence nutrient cycling. Eutrophication is a naturally occurring phenomenon; however, enrichment due to anthropogenic inputs has increased in frequency with largely unknown consequences to benthic macrofaunal assemblages. A decline in infaunal biodiversity is thought to result in the loss of ecosystem function due to increased disturbance in the form of enhanced nutrient addition. This is increasingly important to estuarine habitats, as benthic macrofauna play an important role in controlling sediment porewater nutrient concentrations, nutrient flux to the overlying water column and ultimately ecosystem function. Sediment modification by macrofauna behaviours (e.g. bioturbation) stimulate nutrient regeneration and influence denitrification rate. Thus understanding the responses of macrofauna to enhanced nutrient levels is vital for the understanding and subsequent management of benthic assemblages to estuarine eutrophication. The aim of this thesis was to stress the intertidal sediment of the Kaipara Harbour by the addition of slow-release fertiliser in order to identify key macrofaunal diversity responses and the influence this has in the overall nutrient processing ability. I also examined whether fertiliser addition influenced primary producers, microphytobenthos biomass and the percent coverage of seagrass. 

To gain a better understanding of porewater nutrient elevation and subsequent impacts to macrofaunal diversity, 28 site locations were selected based on high and low functional macrofaunal diversity and abundance characteristics previously identified within Tapora Bank, Kaipara Harbour (Greenfield 2013). Known amounts (1400g m⁻² (high treatment) and 600g m⁻² (medium treatment)) of 70-day slow-release fertiliser (42 % N) was added to the intertidal sediment across a gradient in macrofaunal diversity. Porewater and sediment properties were measured 28 and 47 days after enrichment, with macrofaunal diversity determined on day 47.

The fertiliser enriched plots significantly elevated porewater ammonium concentrations in both treatments in upper (0-2 cm) and lower (5-7 cm) sediment depths. Lower sampling depths had greater concentrations of porewater ammonium than the upper sediments. This elevation resulted a decline in the overall macrofaunal abundance in both addition treatments however, only the decline in key functional species Macomona liliana was significant. The number of functional individuals and number of M. liliana were identified as significant factors controlling the variation in porewater ammonium concentration in ambient sediments. A switch was observed after fertiliser elevation where mud become the sole driver of porewater ammonium concentration in plots of high fertiliser addition. Normalisation treatment porewater ammonium concentration by the control plot values identified both the number of species and number of functional species as important drivers of porewater ammonium processing. No effect of fertiliser enrichment to seagrass percent coverage was observed. 

These results demonstrate that the elevation of porewater ammonium within intertidal sediments may have implications to the diversity and the subsequent functioning of intertidal benthic communities. In particularly, our study highlights the potential loss of functioning related to the decline of key species such as M. liliana; given their role as ecosystem engineers, their loss could reinforce the effects of eutrophication stress on the system and lead to further degradation.

year: 2015

title: “It’s becoming part of their knowing”: a study of bicultural development in an early childhood teacher education setting in Aotearoa/New Zealand

authors: Ritchie, Jenny

abstract: This study is an exploration of the implementation of bicultural development within a university-based early childhood teacher education programme in Aotearoa/New Zealand, which can be considered to be a bicultural country (Walker, 1987, p. 221). Bicultural development is a process in line with obligations contained within the Te Tiriti o Waitangi/The Treaty of Waitangi, which are reflected within the New Zealand Ministry of Education’s Revised Statement of Desirable Objectives and Practices (Ministry of Education, 1996a) and the early childhood curriculum, Te Whāriki (Ministry of Education, 1996b). The study adopts a critical, transformative theoretical paradigm, and employed an eclectic and emergent qualitative methodological approach, that reflected aspects from ethnographic, narrative and grounded theory methodologies. Interviews with university lecturers, early childhood care and education teachers, and professional development facilitators within the early childhood field; observations within early childhood care and education centres; audio taping of university class discussions; samples of university student assignments; and a written survey of graduates of the university teacher education programme provide the sources of data for the study. Central to the methodological process is a commitment to ethical care for participants, which involves attentive accountability to the interpretations that they place on the material that they contribute to the study and to the overall theorising of the significance of the findings. 

Key research questions of the study were to define ‘bicultural development’ in the context of early childhood care and education in this country; to identify key components of the bicultural development implementation process employed within the university teacher early childhood education programme; to distinguish some useful ‘indicators’ of bicultural development within early childhood centres; and to consider the implications for the teacher education programme in terms of preparing graduates to facilitate bicultural development within their future work in early childhood education. 

A significant finding of the study was the identification of a range of strategies for implementing bicultural development in early childhood education teacher education and care and education settings. The key strategies include Tiriti-based partnership models of teaching whereby Māori and Pākehā work alongside each other, enabling the paralleling of Māori and Western perspectives within both university teacher education and early childhood care and education programmes. It was considered essential that universities employ Māori lecturers to enable Māori content within the teacher education programme to be adequately provisioned. Since there are few Māori educators employed in mainstream early childhood services, it was suggested that teachers might seek to employ a “whanaungatanga” approach. This involves the early childhood centre staff creating a climate and environment in which Māori families/whānau are comfortable to participate fully in programme planning, implementation, and evaluation, which will enable all children attending to access Māori perspectives alongside the Western curriculum content. This approach is consistent with Article Two of Te Tiriti o Waitangi, which guaranteed to Māori their tino rangatiratanga, or self-determination. 

An implication for management and staff of early childhood teacher education programmes in Aotearoa/New Zealand is the need to equip graduates with the knowledge bases and commitment that will enable them to implement bicultural development, ideally through adopting, a whanaungatanga approach. This involves facilitating teacher education students to move beyond the dysconscious racism (King, 1994) that is deeply embedded in mainstream Pākehā culture in this country, to the position where they are able to adopt a critical, transformative stance that is humble, respectful and responsive to cultural difference. This stance includes valuing the inclusion of te reo me ōna tikanga throughout early childhood programmes, in a partnership initiated by teachers, but one in which whānau Māori are then able to take the lead in determining the nature and application of Māori content.

text: “It’s becoming part of their knowing”: a study of bicultural development in an early childhood teacher education setting in Aotearoa/New Zealand This study is an exploration of the implementation of bicultural development within a university-based early childhood teacher education programme in Aotearoa/New Zealand, which can be considered to be a bicultural country (Walker, 1987, p. 221). Bicultural development is a process in line with obligations contained within the Te Tiriti o Waitangi/The Treaty of Waitangi, which are reflected within the New Zealand Ministry of Education’s Revised Statement of Desirable Objectives and Practices (Ministry of Education, 1996a) and the early childhood curriculum, Te Whāriki (Ministry of Education, 1996b). The study adopts a critical, transformative theoretical paradigm, and employed an eclectic and emergent qualitative methodological approach, that reflected aspects from ethnographic, narrative and grounded theory methodologies. Interviews with university lecturers, early childhood care and education teachers, and professional development facilitators within the early childhood field; observations within early childhood care and education centres; audio taping of university class discussions; samples of university student assignments; and a written survey of graduates of the university teacher education programme provide the sources of data for the study. Central to the methodological process is a commitment to ethical care for participants, which involves attentive accountability to the interpretations that they place on the material that they contribute to the study and to the overall theorising of the significance of the findings. 

Key research questions of the study were to define ‘bicultural development’ in the context of early childhood care and education in this country; to identify key components of the bicultural development implementation process employed within the university teacher early childhood education programme; to distinguish some useful ‘indicators’ of bicultural development within early childhood centres; and to consider the implications for the teacher education programme in terms of preparing graduates to facilitate bicultural development within their future work in early childhood education. 

A significant finding of the study was the identification of a range of strategies for implementing bicultural development in early childhood education teacher education and care and education settings. The key strategies include Tiriti-based partnership models of teaching whereby Māori and Pākehā work alongside each other, enabling the paralleling of Māori and Western perspectives within both university teacher education and early childhood care and education programmes. It was considered essential that universities employ Māori lecturers to enable Māori content within the teacher education programme to be adequately provisioned. Since there are few Māori educators employed in mainstream early childhood services, it was suggested that teachers might seek to employ a “whanaungatanga” approach. This involves the early childhood centre staff creating a climate and environment in which Māori families/whānau are comfortable to participate fully in programme planning, implementation, and evaluation, which will enable all children attending to access Māori perspectives alongside the Western curriculum content. This approach is consistent with Article Two of Te Tiriti o Waitangi, which guaranteed to Māori their tino rangatiratanga, or self-determination. 

An implication for management and staff of early childhood teacher education programmes in Aotearoa/New Zealand is the need to equip graduates with the knowledge bases and commitment that will enable them to implement bicultural development, ideally through adopting, a whanaungatanga approach. This involves facilitating teacher education students to move beyond the dysconscious racism (King, 1994) that is deeply embedded in mainstream Pākehā culture in this country, to the position where they are able to adopt a critical, transformative stance that is humble, respectful and responsive to cultural difference. This stance includes valuing the inclusion of te reo me ōna tikanga throughout early childhood programmes, in a partnership initiated by teachers, but one in which whānau Māori are then able to take the lead in determining the nature and application of Māori content.

year: 2002