title: Interhemispheric gradient of atmospheric radiocarbon reveals natural variability of Southern Ocean winds

authors: Rodgers, K.B.

subjects: Δ¹⁴C

abstract: Tree ring Δ¹⁴C data (Reimer et al., 2004; McCormac et al., 2004) indicate that atmospheric Δ¹⁴C varied on multi-decadal to centennial timescales, in both hemispheres, over the pre-industrial period AD 950–1830. Although the Northern and Southern Hemispheric Δ¹⁴C records display similar variability, it is difficult from these data alone to distinguish between variations driven by ¹⁴CO₂ production in the upper atmosphere (Stuiver, 1980) and exchanges between carbon reservoirs (Siegenthaler, 1980). Here we consider rather the Interhemispheric Gradient in atmospheric Δ¹⁴C as revealing of the background pre-bomb air-sea Disequilbrium Flux between 14CO₂ and CO₂. As the global maximum of the Disequilibrium Flux is squarely centered in the open ocean regions of the Southern Ocean, relatively modest perturbations to the winds over this region drive significant perturbations to the Interhemispheric Gradient. The analysis presented here implies that changes to Southern Ocean windspeeds are likely a main driver of the observed variability in the Interhemispheric Gradient over 950–1830, and further, that this variability may be larger than the Southern Ocean wind trends that have been reported for recent decades (notably 1980–2004). This interpretation also implies a significant weakening of the winds over the Southern Ocean within a few decades of AD 1375, associated with the transition between the Medieval Climate Anomaly and the Little Ice Age. The driving forces that could have produced such a shift in the winds remain unkown.

text: Interhemispheric gradient of atmospheric radiocarbon reveals natural variability of Southern Ocean winds Tree ring Δ¹⁴C data (Reimer et al., 2004; McCormac et al., 2004) indicate that atmospheric Δ¹⁴C varied on multi-decadal to centennial timescales, in both hemispheres, over the pre-industrial period AD 950–1830. Although the Northern and Southern Hemispheric Δ¹⁴C records display similar variability, it is difficult from these data alone to distinguish between variations driven by ¹⁴CO₂ production in the upper atmosphere (Stuiver, 1980) and exchanges between carbon reservoirs (Siegenthaler, 1980). Here we consider rather the Interhemispheric Gradient in atmospheric Δ¹⁴C as revealing of the background pre-bomb air-sea Disequilbrium Flux between 14CO₂ and CO₂. As the global maximum of the Disequilibrium Flux is squarely centered in the open ocean regions of the Southern Ocean, relatively modest perturbations to the winds over this region drive significant perturbations to the Interhemispheric Gradient. The analysis presented here implies that changes to Southern Ocean windspeeds are likely a main driver of the observed variability in the Interhemispheric Gradient over 950–1830, and further, that this variability may be larger than the Southern Ocean wind trends that have been reported for recent decades (notably 1980–2004). This interpretation also implies a significant weakening of the winds over the Southern Ocean within a few decades of AD 1375, associated with the transition between the Medieval Climate Anomaly and the Little Ice Age. The driving forces that could have produced such a shift in the winds remain unkown.

year: 2011

title: Acoustic tamper detection sensor with very low false alarm rate

authors: Muijlwijk, Lawrence

subjects: false alarms

abstract: We describe a device designed to detect interference (vandalism or tampering) by acoustic means. The design employs both a piezoelectric vibration transducer and a common microphone in a novel mechanical arrangement. In contrast to conventional acoustic sensors that simply respond to vibrations above a threshold, this design analyses the outputs of the two to trigger an alarm. The method confers a near-zero susceptibility to triggering by external loud noises. No complex calculations are required so that only a low-cost, embedded microcontroller is required and the whole sensor can be very cheap. Extreme sensitivity can be achieved with little risk of false alarms.

text: Acoustic tamper detection sensor with very low false alarm rate We describe a device designed to detect interference (vandalism or tampering) by acoustic means. The design employs both a piezoelectric vibration transducer and a common microphone in a novel mechanical arrangement. In contrast to conventional acoustic sensors that simply respond to vibrations above a threshold, this design analyses the outputs of the two to trigger an alarm. The method confers a near-zero susceptibility to triggering by external loud noises. No complex calculations are required so that only a low-cost, embedded microcontroller is required and the whole sensor can be very cheap. Extreme sensitivity can be achieved with little risk of false alarms.

year: 2008

title: Investigating the understanding and implementation of Ka Hikitia, in a New Zealand primary school

authors: Evans, Mary

subjects: Ka Hikitia

abstract: In New Zealand, the education system has underserved Māori learners for many years, with various factors contributing to this underperformance.  Many of these factors stem from racism and bias, conscious or unconscious, inherent in our system (Ministry of Education, 2019b).  Ka Hikitia Accelerating Success 2013 - 2017 (Ministry of Education, 2013a) set about to make transformative change in schools.  This research presents an investigation into the understanding and implementation of Ka Hikitia, in a New Zealand primary school.  
The research was guided by culturally responsive methodologies, bringing together both kaupapa Māori and critical theories (Berryman, 2013b).  Participants’ understandings and how these understandings transferred into their practice was determined through a case study.  The rich information generated within the case was analysed using grounded theory.  The main source of information came from interviewing the management team and teaching staff members.  As an insider/outsider researcher and also a participant, some of my information came from my own observations and knowledge of the school. Some attendance and achievement data held by the school also informed the case.  
The Office of the Auditor-General (2016b) contended that Ka Hikitia was a well-worded policy but, due to a lack of understanding of the policy in many schools, it was poorly implemented nationwide.  In this school, despite the good leadership and hard-working teachers, staff had difficulty fully understanding and therefore implementing the Ka Hikitia strategy as it was intended.  Strong relationships between teachers and students were evident throughout the study, however, stronger relationships were needed between the school and the wider Māori community.  The research shows that, despite the good intentions of the teachers, to fully implement the intent of Ka Hikitia, educators need to be committed to te ao Māori.  
The Ministry of Education plans to relaunch a further iteration of Ka Hikitia this year, supported by another initiative, Te Hurihanganui.  For this iteration to be successful, more effective implementation systems are required that will enable Māori students to enjoy and achieve educational success as Māori.

text: Investigating the understanding and implementation of Ka Hikitia, in a New Zealand primary school In New Zealand, the education system has underserved Māori learners for many years, with various factors contributing to this underperformance.  Many of these factors stem from racism and bias, conscious or unconscious, inherent in our system (Ministry of Education, 2019b).  Ka Hikitia Accelerating Success 2013 - 2017 (Ministry of Education, 2013a) set about to make transformative change in schools.  This research presents an investigation into the understanding and implementation of Ka Hikitia, in a New Zealand primary school.  
The research was guided by culturally responsive methodologies, bringing together both kaupapa Māori and critical theories (Berryman, 2013b).  Participants’ understandings and how these understandings transferred into their practice was determined through a case study.  The rich information generated within the case was analysed using grounded theory.  The main source of information came from interviewing the management team and teaching staff members.  As an insider/outsider researcher and also a participant, some of my information came from my own observations and knowledge of the school. Some attendance and achievement data held by the school also informed the case.  
The Office of the Auditor-General (2016b) contended that Ka Hikitia was a well-worded policy but, due to a lack of understanding of the policy in many schools, it was poorly implemented nationwide.  In this school, despite the good leadership and hard-working teachers, staff had difficulty fully understanding and therefore implementing the Ka Hikitia strategy as it was intended.  Strong relationships between teachers and students were evident throughout the study, however, stronger relationships were needed between the school and the wider Māori community.  The research shows that, despite the good intentions of the teachers, to fully implement the intent of Ka Hikitia, educators need to be committed to te ao Māori.  
The Ministry of Education plans to relaunch a further iteration of Ka Hikitia this year, supported by another initiative, Te Hurihanganui.  For this iteration to be successful, more effective implementation systems are required that will enable Māori students to enjoy and achieve educational success as Māori.

year: 2020