title: Cyanolichens can have both cyanobacteria and green algae in a common layer as major contributors to photosynthesis

authors: Henskens, Frieda L.

subjects: green algae

abstract: BACKGROUND AND AIMS:
Cyanolichens are usually stated to be bipartite (mycobiont plus cyanobacterial photobiont). Analyses revealed green algal carbohydrates in supposedly cyanobacterial lichens (in the genera Pseudocyphellaria, Sticta and Peltigera). Investigations were carried out to determine if both cyanobacteria and green algae were present in these lichens and, if so, what were their roles.
METHODS:
The types of photobiont present were determined by light and fluorescence microscopy. Small carbohydrates were analysed to detect the presence of green algal metabolites. Thalli were treated with selected strengths of Zn²⁺ solutions that stop cyanobacterial but not green algal photosynthesis. CO₂ exchange was measured before and after treatment to determine the contribution of each photobiont to total thallus photosynthesis. Heterocyst frequencies were determined to clarify whether the cyanobacteria were modified for increased nitrogen fixation (high heterocyst frequencies) or were normal, vegetative cells.
KEY RESULTS:
Several cyanobacterial lichens had green algae present in the photosynthetic layer of the thallus. The presence of the green algal transfer carbohydrate (ribitol) and the incomplete inhibition of thallus photosynthesis upon treatment with Zn²⁺ solutions showed that both photobionts contributed to the photosynthesis of the lichen thallus. Low heterocyst frequencies showed that, despite the presence of adjacent green algae, the cyanobacteria were not altered to increase nitrogen fixation.
CONCLUSIONS:
These cyanobacterial lichens are a tripartite lichen symbiont combination in which the mycobiont has two primarily photosynthetic photobionts, 'co-primary photobionts', a cyanobacterium (dominant) and a green alga. This demonstrates high flexibility in photobiont choice by the mycobiont in the Peltigerales. Overall thallus appearance does not change whether one or two photobionts are present in the cyanobacterial thallus. This suggests that, if there is a photobiont effect on thallus structure, it is not specific to one or the other photobiont.

text: Cyanolichens can have both cyanobacteria and green algae in a common layer as major contributors to photosynthesis BACKGROUND AND AIMS:
Cyanolichens are usually stated to be bipartite (mycobiont plus cyanobacterial photobiont). Analyses revealed green algal carbohydrates in supposedly cyanobacterial lichens (in the genera Pseudocyphellaria, Sticta and Peltigera). Investigations were carried out to determine if both cyanobacteria and green algae were present in these lichens and, if so, what were their roles.
METHODS:
The types of photobiont present were determined by light and fluorescence microscopy. Small carbohydrates were analysed to detect the presence of green algal metabolites. Thalli were treated with selected strengths of Zn²⁺ solutions that stop cyanobacterial but not green algal photosynthesis. CO₂ exchange was measured before and after treatment to determine the contribution of each photobiont to total thallus photosynthesis. Heterocyst frequencies were determined to clarify whether the cyanobacteria were modified for increased nitrogen fixation (high heterocyst frequencies) or were normal, vegetative cells.
KEY RESULTS:
Several cyanobacterial lichens had green algae present in the photosynthetic layer of the thallus. The presence of the green algal transfer carbohydrate (ribitol) and the incomplete inhibition of thallus photosynthesis upon treatment with Zn²⁺ solutions showed that both photobionts contributed to the photosynthesis of the lichen thallus. Low heterocyst frequencies showed that, despite the presence of adjacent green algae, the cyanobacteria were not altered to increase nitrogen fixation.
CONCLUSIONS:
These cyanobacterial lichens are a tripartite lichen symbiont combination in which the mycobiont has two primarily photosynthetic photobionts, 'co-primary photobionts', a cyanobacterium (dominant) and a green alga. This demonstrates high flexibility in photobiont choice by the mycobiont in the Peltigerales. Overall thallus appearance does not change whether one or two photobionts are present in the cyanobacterial thallus. This suggests that, if there is a photobiont effect on thallus structure, it is not specific to one or the other photobiont.

year: 2012

title: Assessment for learning in primary technology classrooms

authors: Moreland, Judy

subjects: primary

abstract: Emerging international research suggests that enhancing teacher student assessment for learning (AfL) interactions is a key to enhancing student learning. Planning frameworks that make explicit the multiple dimensions of technology can be used to extend teacher knowledge and focus interaction. Effective AfL interactions in technology encompass the multidimensional nature of technology, help students build continuity and coherence between ideas and actions over time, and are multimodal. AfL in primary technology classrooms is complex. Yet in this complexity there are rich opportunities for effective AfL interactions that contribute to students’ technology
learning.

text: Assessment for learning in primary technology classrooms Emerging international research suggests that enhancing teacher student assessment for learning (AfL) interactions is a key to enhancing student learning. Planning frameworks that make explicit the multiple dimensions of technology can be used to extend teacher knowledge and focus interaction. Effective AfL interactions in technology encompass the multidimensional nature of technology, help students build continuity and coherence between ideas and actions over time, and are multimodal. AfL in primary technology classrooms is complex. Yet in this complexity there are rich opportunities for effective AfL interactions that contribute to students’ technology
learning.

year: 2007

title: Faith, politics and reconciliation: the Roman Catholic Church, New Zealand Maori and indigenous Australians

authors: O'Sullivan, Dominic

abstract: The Roman Catholic Church claims from Jesus Christ a mission to teach consistently religious ideals in accordance with its understanding of God’s constant truth. These ideals include the belief that human creation in the image and likeness of God establishes rights to dignity, to culture, to religious freedom, to self-determination and a share in the common good. These ideals form the basis of the unique contribution to human affairs which the Church claims it can make. Although these are religious goals for the Church, they require political realisation, which means that the Church cannot but be alert to the formation of alliances of common intellectual aspiration around concrete political issues so that secular expression and context can be given to the magisterium (the Church’s body of teaching). At the same time the Catholic hierarchy is conscious of a need for caution in how it responds to political events lest that religious mission be compromised by a perception of it as a partisan political lobby group, thus lessening its capacity to make its unique contribution to human affairs. 

The Second Vatican Council reaffirmed that the Church’s religious objectives do not exist in isolation from the political order because human law, which is developed through the secular political process, should conform to the religious natural law. Prior to the Council’s reaffirmation the Australian and New Zealand Churches generally, but not exclusively, understated or misunderstood this relationship and became impotent in challenging secular objectives inconsistent with religious aspiration. In contrast when the Church has accepted the relationship, as it has since the Second Vatican Council, it has positioned itself to identify opportunities to give secular context and expression to religious thought. Such opportunities increased from the 1960s onwards as political developments in both Australia and New Zealand saw a secular questioning of racism and a broadening of the parameters of secular political debate to the extent that established Catholic thought was shifted from the fringes to the widening mainstream of public opinion on indigenous policy. 

Although the Second Vatican Council required attention to the relationship between religious ends and political means, the changing secular environment was a significant factor in encouraging public advocacy in support of indigenous aspiration, which peaked in Australia in the 1990s with substantial Church interest in the native title debate and with the Church playing a leading role in the entrenchment of reconciliation - a religious concept - on the Australian political landscape. In New Zealand there has been an equal but less vocal interest in reconciliation because the political process itself established the Treaty of Waitangi as a political context for reconciliation and a context around which the Church has been able to focus its interest in the advancement of Maori aspiration. Yet, while the Treaty of Waitangi and the associated bicultural discourse have provided contexts for the expression of religious principle, they have also detracted from the Church’s use of its own magisterium as the moral authority for the articulation of its aspirations for Maori.

text: Faith, politics and reconciliation: the Roman Catholic Church, New Zealand Maori and indigenous Australians The Roman Catholic Church claims from Jesus Christ a mission to teach consistently religious ideals in accordance with its understanding of God’s constant truth. These ideals include the belief that human creation in the image and likeness of God establishes rights to dignity, to culture, to religious freedom, to self-determination and a share in the common good. These ideals form the basis of the unique contribution to human affairs which the Church claims it can make. Although these are religious goals for the Church, they require political realisation, which means that the Church cannot but be alert to the formation of alliances of common intellectual aspiration around concrete political issues so that secular expression and context can be given to the magisterium (the Church’s body of teaching). At the same time the Catholic hierarchy is conscious of a need for caution in how it responds to political events lest that religious mission be compromised by a perception of it as a partisan political lobby group, thus lessening its capacity to make its unique contribution to human affairs. 

The Second Vatican Council reaffirmed that the Church’s religious objectives do not exist in isolation from the political order because human law, which is developed through the secular political process, should conform to the religious natural law. Prior to the Council’s reaffirmation the Australian and New Zealand Churches generally, but not exclusively, understated or misunderstood this relationship and became impotent in challenging secular objectives inconsistent with religious aspiration. In contrast when the Church has accepted the relationship, as it has since the Second Vatican Council, it has positioned itself to identify opportunities to give secular context and expression to religious thought. Such opportunities increased from the 1960s onwards as political developments in both Australia and New Zealand saw a secular questioning of racism and a broadening of the parameters of secular political debate to the extent that established Catholic thought was shifted from the fringes to the widening mainstream of public opinion on indigenous policy. 

Although the Second Vatican Council required attention to the relationship between religious ends and political means, the changing secular environment was a significant factor in encouraging public advocacy in support of indigenous aspiration, which peaked in Australia in the 1990s with substantial Church interest in the native title debate and with the Church playing a leading role in the entrenchment of reconciliation - a religious concept - on the Australian political landscape. In New Zealand there has been an equal but less vocal interest in reconciliation because the political process itself established the Treaty of Waitangi as a political context for reconciliation and a context around which the Church has been able to focus its interest in the advancement of Maori aspiration. Yet, while the Treaty of Waitangi and the associated bicultural discourse have provided contexts for the expression of religious principle, they have also detracted from the Church’s use of its own magisterium as the moral authority for the articulation of its aspirations for Maori.

year: 2003