title: Findings from an in-depth annual tree-ring radiocarbon intercomparison

authors: Wacker, L.

subjects: annual tree rings

abstract: The radiocarbon (¹⁴C) calibration curve so far contains annually resolved data only for a short period of time. With accelerator mass spectrometry (AMS) matching the precision of decay counting, it is now possible to efficiently produce large datasets of annual resolution for calibration purposes using small amounts of wood. The radiocarbon intercomparison on single-year tree-ring samples presented here is the first to investigate specifically possible offsets between AMS laboratories at high precision. The results show that AMS laboratories are capable of measuring samples of Holocene age with an accuracy and precision that is comparable or even goes beyond what is possible with decay counting, even though they require a thousand times less wood. It also shows that not all AMS laboratories always produce results that are consistent with their stated uncertainties. The long-term benefits of studies of this kind are more accurate radiocarbon measurements with, in the future, better quantified uncertainties.

text: Findings from an in-depth annual tree-ring radiocarbon intercomparison The radiocarbon (¹⁴C) calibration curve so far contains annually resolved data only for a short period of time. With accelerator mass spectrometry (AMS) matching the precision of decay counting, it is now possible to efficiently produce large datasets of annual resolution for calibration purposes using small amounts of wood. The radiocarbon intercomparison on single-year tree-ring samples presented here is the first to investigate specifically possible offsets between AMS laboratories at high precision. The results show that AMS laboratories are capable of measuring samples of Holocene age with an accuracy and precision that is comparable or even goes beyond what is possible with decay counting, even though they require a thousand times less wood. It also shows that not all AMS laboratories always produce results that are consistent with their stated uncertainties. The long-term benefits of studies of this kind are more accurate radiocarbon measurements with, in the future, better quantified uncertainties.

year: 2020

title: The relationship between physiological and performance variables during a hot/humid international rugby sevens tournament

authors: Fenemor, Stephen Paul

subjects: Science & Technology

abstract: Purpose: To characterise core temperature (Tc) along with predictors of Tc during an international rugby sevens tournament played in hot/humid conditions. 

Methods: Tc was collected from 11 elite men’s rugby sevens athletes (age 24 ± 3 years) competing in the Oceania sevens tournament in Suva, Fiji. Game specific external load data [playing minutes, total running distance, high speed running distance (HSD)], psychrometric wet bulb temperature (WBTp) and exertional heat illness (EHI) symptoms were also collected. Cohen’s effect sizes (d) were used to assess differences in Tc across measurement periods was, while linear regression was used to assess the effect of external load and post warm-up Tc on peak game Tc.
 
Results: Compared to baseline on both tournament days, mean Tc was higher at all subsequent time-points, including between games (all d > 1.30). On both tournament days, eight athletes (~73%) reached a peak game Tc > 39.0 °C. with several athletes reaching > 39.0 °C during warm-ups. The final game of the tournament recorded the highest mean peak Tc (39.1 ± 0.3 °C). Mean Tc was related to playing minutes, total running distance, HSD, and post warm-up Tc (all p < 0.01). 

Conclusions: Tc during warm-ups and games regularly exceeded those demonstrated to be detrimental to repeated sprint performance (> 39 °C). Warm-up Tc represents the easiest predictor of game peak Tc to control via the use of appropriate pre- and per-cooling strategies. Practitioners should be prepared to modulate warm-ups and other heat preparation strategies based on likely environmental conditions faced in these tournaments.

text: The relationship between physiological and performance variables during a hot/humid international rugby sevens tournament Purpose: To characterise core temperature (Tc) along with predictors of Tc during an international rugby sevens tournament played in hot/humid conditions. 

Methods: Tc was collected from 11 elite men’s rugby sevens athletes (age 24 ± 3 years) competing in the Oceania sevens tournament in Suva, Fiji. Game specific external load data [playing minutes, total running distance, high speed running distance (HSD)], psychrometric wet bulb temperature (WBTp) and exertional heat illness (EHI) symptoms were also collected. Cohen’s effect sizes (d) were used to assess differences in Tc across measurement periods was, while linear regression was used to assess the effect of external load and post warm-up Tc on peak game Tc.
 
Results: Compared to baseline on both tournament days, mean Tc was higher at all subsequent time-points, including between games (all d > 1.30). On both tournament days, eight athletes (~73%) reached a peak game Tc > 39.0 °C. with several athletes reaching > 39.0 °C during warm-ups. The final game of the tournament recorded the highest mean peak Tc (39.1 ± 0.3 °C). Mean Tc was related to playing minutes, total running distance, HSD, and post warm-up Tc (all p < 0.01). 

Conclusions: Tc during warm-ups and games regularly exceeded those demonstrated to be detrimental to repeated sprint performance (> 39 °C). Warm-up Tc represents the easiest predictor of game peak Tc to control via the use of appropriate pre- and per-cooling strategies. Practitioners should be prepared to modulate warm-ups and other heat preparation strategies based on likely environmental conditions faced in these tournaments.

year: 2021-09-22

title: ‘He reka te wai o te hua pango: The darker the berry the sweeter the juice.' The experiences of Māori women in educational leadership in mainstream secondary schools.

authors: Taukamo, Trudy

subjects: New Zealand leadership

abstract: Although there has been a growing interest in Māori women in educational leadership, the research base in New Zealand is still limited. This study provides insights into the challenges and experiences of four Māori women who occupy a formal leadership position in a mainstream secondary school. It used a qualitative kaupapa Māori research framework. Data were collected using semi-structured one-on-one interview with open-ended questions. The four women were selected from Māori women who currently hold a formal leadership position at a senior management level in a mainstream secondary school and who identify as Māori. The reason for the purposive sample was the critical under-representation of Māori women in formal educational leadership roles. This study revealed three important aspects. Firstly, a person’s upbringing and background has a significant impact on the principles and values which underpin leadership. Secondly, it was evident that a support system whether personal or professional was crucial in a leadership position. Finally, the influences of opportunities and appointments to leadership were important in educational leadership. Clearly, the findings point to a need for a stronger mentoring programme and effective networking of Māori women. Tertiary studies and leadership programs can aid the career pathways for aspiring leaders. However, what is clear is the need for more research specific to the New Zealand context and Māori women.

text: ‘He reka te wai o te hua pango: The darker the berry the sweeter the juice.' The experiences of Māori women in educational leadership in mainstream secondary schools. Although there has been a growing interest in Māori women in educational leadership, the research base in New Zealand is still limited. This study provides insights into the challenges and experiences of four Māori women who occupy a formal leadership position in a mainstream secondary school. It used a qualitative kaupapa Māori research framework. Data were collected using semi-structured one-on-one interview with open-ended questions. The four women were selected from Māori women who currently hold a formal leadership position at a senior management level in a mainstream secondary school and who identify as Māori. The reason for the purposive sample was the critical under-representation of Māori women in formal educational leadership roles. This study revealed three important aspects. Firstly, a person’s upbringing and background has a significant impact on the principles and values which underpin leadership. Secondly, it was evident that a support system whether personal or professional was crucial in a leadership position. Finally, the influences of opportunities and appointments to leadership were important in educational leadership. Clearly, the findings point to a need for a stronger mentoring programme and effective networking of Māori women. Tertiary studies and leadership programs can aid the career pathways for aspiring leaders. However, what is clear is the need for more research specific to the New Zealand context and Māori women.

year: 2011