title: The ecological dichotomy of ammonia-oxidizing archaea and bacteria in the hyper-arid soils of the Antarctic Dry Valleys

authors: Magalhães, Catarina M.

subjects: archaea

abstract: The McMurdo Dry Valleys of Antarctica are considered to be one of the most physically and chemically extreme terrestrial environments on the Earth. However, little is known about the organisms involved in nitrogen transformations in these environments. In this study, we investigated the diversity and abundance of ammonia-oxidizing archaea (AOA) and bacteria (AOB) in four McMurdo Dry Valleys with highly variable soil geochemical properties and climatic conditions: Miers Valley, Upper Wright Valley, Beacon Valley and Battleship Promontory. The bacterial communities of these four Dry Valleys have been examined previously, and the results suggested that the extremely localized bacterial diversities are likely driven by the disparate physicochemical conditions associated with these locations. Here we showed that AOB and AOA amoA gene diversity was generally low; only four AOA and three AOB operational taxonomic units (OTUs) were identified from a total of 420 AOA and AOB amoA clones. Quantitative PCR analysis of amoA genes revealed clear differences in the relative abundances of AOA and AOB amoA genes among samples from the four dry valleys. Although AOB amoA gene dominated the ammonia-oxidizing community in soils from Miers Valley and Battleship Promontory, AOA amoA gene were more abundant in samples from Upper Wright and Beacon Valleys, where the environmental conditions are considerably harsher (e.g., extremely low soil C/N ratios and much higher soil electrical conductivity). Correlations between environmental variables and amoA genes copy numbers, as examined by redundancy analysis (RDA), revealed that higher AOA/AOB ratios were closely related to soils with high salts and Cu contents and low pH. Our findings hint at a dichotomized distribution of AOA and AOB within the Dry Valleys, potentially driven by environmental constraints.

text: The ecological dichotomy of ammonia-oxidizing archaea and bacteria in the hyper-arid soils of the Antarctic Dry Valleys The McMurdo Dry Valleys of Antarctica are considered to be one of the most physically and chemically extreme terrestrial environments on the Earth. However, little is known about the organisms involved in nitrogen transformations in these environments. In this study, we investigated the diversity and abundance of ammonia-oxidizing archaea (AOA) and bacteria (AOB) in four McMurdo Dry Valleys with highly variable soil geochemical properties and climatic conditions: Miers Valley, Upper Wright Valley, Beacon Valley and Battleship Promontory. The bacterial communities of these four Dry Valleys have been examined previously, and the results suggested that the extremely localized bacterial diversities are likely driven by the disparate physicochemical conditions associated with these locations. Here we showed that AOB and AOA amoA gene diversity was generally low; only four AOA and three AOB operational taxonomic units (OTUs) were identified from a total of 420 AOA and AOB amoA clones. Quantitative PCR analysis of amoA genes revealed clear differences in the relative abundances of AOA and AOB amoA genes among samples from the four dry valleys. Although AOB amoA gene dominated the ammonia-oxidizing community in soils from Miers Valley and Battleship Promontory, AOA amoA gene were more abundant in samples from Upper Wright and Beacon Valleys, where the environmental conditions are considerably harsher (e.g., extremely low soil C/N ratios and much higher soil electrical conductivity). Correlations between environmental variables and amoA genes copy numbers, as examined by redundancy analysis (RDA), revealed that higher AOA/AOB ratios were closely related to soils with high salts and Cu contents and low pH. Our findings hint at a dichotomized distribution of AOA and AOB within the Dry Valleys, potentially driven by environmental constraints.

year: 2014-09-30

title: Improving the Training of Pre-Service Physics Teachers in Malaysia using Didaktik Analysis

authors: Ishak, Mohd. Zaki

subjects: Physics Education

abstract: The research in this thesis examined the use of a didaktik-based approach to thinking about teaching and learning to the training of pre-service physics teachers in a Malaysian teacher training programme. The process of developing a specific content knowledge (real or true physics) was done through a didaktik analysis of specific physics content, to develop physics content knowledge suitable for schooling, in a particular educational context. Didaktik analysis used as intervention in this study involved: analysing specific physics content as contained in the curriculum specifications and textbooks; analysis of literature on students' alternative conceptions; developing a lesson plan; developing teaching sequences that involve teaching and learning activities, enacting lesson plans and teaching sequence in the microteaching and practicum, and subsequent reflection.
Klafki's (2000) model of didaktik analysis was used as the basis of an intervention employed in a physics teaching methods course (TT4133) at the School of Education, University of Malaysia Sabah (UMS). The intervention consisted of the 14 week course: first seven weeks on theoretical aspects of teaching methods, followed the usual course synopsis, but with modifications in content resulting from didaktik analysis, and the remainder dealt with microteaching; and 8 weeks practicum.  To illustrate the use of didaktik analysis in the training programme, the specific physics content in the areas of force and motion was provided as an example, showing how this was presented to the pre-service physics teachers in the programme. The researcher began with a conceptual analysis of force and motion as presented in the Malaysian secondary physics curriculum specifications and textbooks. This was followed by analysis of the science education literature on students' alternative conceptions involving force and motion, analysis of textbooks presentations of force and motion, and importantly a synopsis of the history of scientific thinking about force and motion. Subsequently, the pre-service teachers were required to prepare lesson plans aided by the researcher based on the above tasks, and this was followed by the development of a teaching sequence which was intended to be implemented in teaching practice with peers (called microteaching in Malaysia), and after further refinement in the practicum in a real classroom (under supervision). 
Participants were third year (15 males and 20 females) and fourth year (18 males and 60 females) pre-service physics teachers in their final year of undergraduate studies. The third year cohort consisted of experienced primary school teachers seeking to become secondary school physics teachers via a three-year conversion course. The fourth year cohort had no prior teaching experience, but held degree-level qualifications in physics. Quantitative data were gathered through two tests of conceptual understanding, The Test of Understanding Graph in Kinematics, TUG-K and The Force and Motion Conceptual Evaluation, FMCE tests, and a purpose-designed instrument the Beliefs About Physics Teaching, BAPT questionnaire. Qualitative data were constructed through the inspection of self-written reports about prior physics learning experiences, inspection of assignments on the didaktik analysis of physics, and individual lesson plans. Video recording and field notes made during observations of microteaching and the practicum, examination of 'written reflections' done in the middle of the methods course, during the practicum, and in the final examinations, and interviews and field notes made by the researcher during meetings with the pre-service physics teachers, completed the data corpus. 
The research findings indicate that generally both cohorts had difficulty understanding kinematics graphs, and weak conceptual understanding of Newtonian concepts. These findings support the findings from the BAPT questionnaire and interviews, which point to perceptions of lack of ability to teach physics, negative attitudes towards teaching specific physics topics at the secondary level, and overall low physics teaching self-efficacy. Overall the findings from the BAPT questionnaire and interviews, before the intervention based on didaktik analysis of physics suggest that these pre-service physics teachers' attitude toward, and beliefs about, physics teaching were based on career interest in teaching, and not on any intrinsic interest in physics or physics teaching as a profession.
After the didaktik analysis intervention it seems that the pre-service physics teachers' teaching practices were shaped by their beliefs about, and experiences of, the physics teaching methods course generally, and the didaktik analysis experience in particular. Overall, it seems this part of methods course helped to improve pre-service physics teachers' understanding of specific physics content, improved their attitude-toward-physics and teaching, helped them to identify problems with students' learning of physics concepts, and helped their teaching practice, subsequently making them more confident about teaching secondary school physics.
The pre-service physics teachers commented on the value of didaktik analysis and this was evident in the microteaching, but not in lesson plans and teaching sequence used in the practicum. It seems this was as a result of a limited amount and a drive by schools to adhere to curriculum specifications. Overall it seems the introduction of didaktik-based analysis intervention increased participants' confidence to teach secondary school physics and that these pre-service physics teachers have gone some way in developing into reflective practitioners in terms of their experiences of: their own secondary physics learning; their physics methods course, both of which led to a better and deeper understanding of physics and methods course content; and the teaching practices in the microteaching and practicum, both of which gave confidence to teach secondary school physics.
Three recommendations are made from this thesis. First, the introduction of a didaktik analysis-based intervention in physics teaching methods courses such as the one in this study, necessitates identification in advance of pre-service physics teachers' attitude toward, and beliefs about physics teaching, along with their attitude-toward-physics and learning, their physics teaching self-efficacy beliefs, and their conceptual understanding of specific physics content. Second, didaktik analysis involving other specific physics content, with other cohorts of pre-service physics teachers, experienced secondary physics teachers, and physicists, is worthy of consideration. Third, the success of the use of a didaktik-based analysis in a physics teaching methods courses requires scaffolding of the teaching sequences employed, and strong support from associate/mentor teachers during the practicum, if didaktik-based teaching is to be realized in the classroom.

text: Improving the Training of Pre-Service Physics Teachers in Malaysia using Didaktik Analysis The research in this thesis examined the use of a didaktik-based approach to thinking about teaching and learning to the training of pre-service physics teachers in a Malaysian teacher training programme. The process of developing a specific content knowledge (real or true physics) was done through a didaktik analysis of specific physics content, to develop physics content knowledge suitable for schooling, in a particular educational context. Didaktik analysis used as intervention in this study involved: analysing specific physics content as contained in the curriculum specifications and textbooks; analysis of literature on students' alternative conceptions; developing a lesson plan; developing teaching sequences that involve teaching and learning activities, enacting lesson plans and teaching sequence in the microteaching and practicum, and subsequent reflection.
Klafki's (2000) model of didaktik analysis was used as the basis of an intervention employed in a physics teaching methods course (TT4133) at the School of Education, University of Malaysia Sabah (UMS). The intervention consisted of the 14 week course: first seven weeks on theoretical aspects of teaching methods, followed the usual course synopsis, but with modifications in content resulting from didaktik analysis, and the remainder dealt with microteaching; and 8 weeks practicum.  To illustrate the use of didaktik analysis in the training programme, the specific physics content in the areas of force and motion was provided as an example, showing how this was presented to the pre-service physics teachers in the programme. The researcher began with a conceptual analysis of force and motion as presented in the Malaysian secondary physics curriculum specifications and textbooks. This was followed by analysis of the science education literature on students' alternative conceptions involving force and motion, analysis of textbooks presentations of force and motion, and importantly a synopsis of the history of scientific thinking about force and motion. Subsequently, the pre-service teachers were required to prepare lesson plans aided by the researcher based on the above tasks, and this was followed by the development of a teaching sequence which was intended to be implemented in teaching practice with peers (called microteaching in Malaysia), and after further refinement in the practicum in a real classroom (under supervision). 
Participants were third year (15 males and 20 females) and fourth year (18 males and 60 females) pre-service physics teachers in their final year of undergraduate studies. The third year cohort consisted of experienced primary school teachers seeking to become secondary school physics teachers via a three-year conversion course. The fourth year cohort had no prior teaching experience, but held degree-level qualifications in physics. Quantitative data were gathered through two tests of conceptual understanding, The Test of Understanding Graph in Kinematics, TUG-K and The Force and Motion Conceptual Evaluation, FMCE tests, and a purpose-designed instrument the Beliefs About Physics Teaching, BAPT questionnaire. Qualitative data were constructed through the inspection of self-written reports about prior physics learning experiences, inspection of assignments on the didaktik analysis of physics, and individual lesson plans. Video recording and field notes made during observations of microteaching and the practicum, examination of 'written reflections' done in the middle of the methods course, during the practicum, and in the final examinations, and interviews and field notes made by the researcher during meetings with the pre-service physics teachers, completed the data corpus. 
The research findings indicate that generally both cohorts had difficulty understanding kinematics graphs, and weak conceptual understanding of Newtonian concepts. These findings support the findings from the BAPT questionnaire and interviews, which point to perceptions of lack of ability to teach physics, negative attitudes towards teaching specific physics topics at the secondary level, and overall low physics teaching self-efficacy. Overall the findings from the BAPT questionnaire and interviews, before the intervention based on didaktik analysis of physics suggest that these pre-service physics teachers' attitude toward, and beliefs about, physics teaching were based on career interest in teaching, and not on any intrinsic interest in physics or physics teaching as a profession.
After the didaktik analysis intervention it seems that the pre-service physics teachers' teaching practices were shaped by their beliefs about, and experiences of, the physics teaching methods course generally, and the didaktik analysis experience in particular. Overall, it seems this part of methods course helped to improve pre-service physics teachers' understanding of specific physics content, improved their attitude-toward-physics and teaching, helped them to identify problems with students' learning of physics concepts, and helped their teaching practice, subsequently making them more confident about teaching secondary school physics.
The pre-service physics teachers commented on the value of didaktik analysis and this was evident in the microteaching, but not in lesson plans and teaching sequence used in the practicum. It seems this was as a result of a limited amount and a drive by schools to adhere to curriculum specifications. Overall it seems the introduction of didaktik-based analysis intervention increased participants' confidence to teach secondary school physics and that these pre-service physics teachers have gone some way in developing into reflective practitioners in terms of their experiences of: their own secondary physics learning; their physics methods course, both of which led to a better and deeper understanding of physics and methods course content; and the teaching practices in the microteaching and practicum, both of which gave confidence to teach secondary school physics.
Three recommendations are made from this thesis. First, the introduction of a didaktik analysis-based intervention in physics teaching methods courses such as the one in this study, necessitates identification in advance of pre-service physics teachers' attitude toward, and beliefs about physics teaching, along with their attitude-toward-physics and learning, their physics teaching self-efficacy beliefs, and their conceptual understanding of specific physics content. Second, didaktik analysis involving other specific physics content, with other cohorts of pre-service physics teachers, experienced secondary physics teachers, and physicists, is worthy of consideration. Third, the success of the use of a didaktik-based analysis in a physics teaching methods courses requires scaffolding of the teaching sequences employed, and strong support from associate/mentor teachers during the practicum, if didaktik-based teaching is to be realized in the classroom.

year: 2008

title: Nobody knows me even though I’m always there: Why Māori men do exist - in all the wrong places

authors: Stanley, Paul

subjects: Maori

abstract: In the study of psychology, Māori men are often only seen as the perpetrators of the problems. There is very little focus on finding solutions for Māori men, with Māori men. In the top eight causes of death for Māori males aged 15 to 24 are car crashes, homicide, and suicide. With respect to car crashes, there is a close link between alcohol-related car crashes and suicide. As a nation, we should be concerned with all of the above issues, as each of them is preventable. Invariably, we fail see the deaths of these young men as warning signs of much wider issues about why they wanted to die, or why they felt the need to kill someone close to themselves. The argument tendered in this paper is that the same way in which Māori as a group have been researched, as being “the problem”, equally applies to the way in which Māori men have continued to be have been researched: Māori men are only ever portrayed as “the problem” and are never portrayed as part of a solution subjected to this process as well. The lyrics of a well known song by UB40, One in Ten, exemplify this notion of being unknown, even though Māori men do exist in Aotearoa.

text: Nobody knows me even though I’m always there: Why Māori men do exist - in all the wrong places In the study of psychology, Māori men are often only seen as the perpetrators of the problems. There is very little focus on finding solutions for Māori men, with Māori men. In the top eight causes of death for Māori males aged 15 to 24 are car crashes, homicide, and suicide. With respect to car crashes, there is a close link between alcohol-related car crashes and suicide. As a nation, we should be concerned with all of the above issues, as each of them is preventable. Invariably, we fail see the deaths of these young men as warning signs of much wider issues about why they wanted to die, or why they felt the need to kill someone close to themselves. The argument tendered in this paper is that the same way in which Māori as a group have been researched, as being “the problem”, equally applies to the way in which Māori men have continued to be have been researched: Māori men are only ever portrayed as “the problem” and are never portrayed as part of a solution subjected to this process as well. The lyrics of a well known song by UB40, One in Ten, exemplify this notion of being unknown, even though Māori men do exist in Aotearoa.

year: 2003