title: Enzyme activity down to −100°C

authors: Bragger, J.M.

subjects: Alkaline phosphatise

abstract: The activities of two enzymes, beef liver catalase (EC 1.11.1.6) and calf intestine alkaline phosphatase (EC 3.1.3.1), have been measured down to −97°C and −100°C, respectively. Enzyme activity has not previously been measured at such low temperatures. For catalase, the cryosolvents used were methanol:ethylene glycol:water (70:10:20) and DMSO:ethylene glycol:water (60:20:20). For alkaline phosphatase, methanol:ethylene glycol:water (70:10:20) was used. All of the Arrhenius plots were linear over the whole of the temperature range examined. Since the lowest temperatures at which activity was measured are well below the dynamic transition observed for proteins, the results indicate that the motions which cease below the dynamic transition are not essential for enzyme activity. In all cases the use of cryosolvent led to substantial increases in Arrhenius activation energies, and this imposed practical limitations on the measurement of enzyme activity below −100°C. At even lower temperatures, enzyme activity may be limited by the effect of solvent fluidity on substrate/product diffusion, but overall there is no evidence that any intrinsic enzyme property imposes a lower temperature limit for enzyme activity.

text: Enzyme activity down to −100°C The activities of two enzymes, beef liver catalase (EC 1.11.1.6) and calf intestine alkaline phosphatase (EC 3.1.3.1), have been measured down to −97°C and −100°C, respectively. Enzyme activity has not previously been measured at such low temperatures. For catalase, the cryosolvents used were methanol:ethylene glycol:water (70:10:20) and DMSO:ethylene glycol:water (60:20:20). For alkaline phosphatase, methanol:ethylene glycol:water (70:10:20) was used. All of the Arrhenius plots were linear over the whole of the temperature range examined. Since the lowest temperatures at which activity was measured are well below the dynamic transition observed for proteins, the results indicate that the motions which cease below the dynamic transition are not essential for enzyme activity. In all cases the use of cryosolvent led to substantial increases in Arrhenius activation energies, and this imposed practical limitations on the measurement of enzyme activity below −100°C. At even lower temperatures, enzyme activity may be limited by the effect of solvent fluidity on substrate/product diffusion, but overall there is no evidence that any intrinsic enzyme property imposes a lower temperature limit for enzyme activity.

year: 2000

title: The development of teacher self and collective efficacy through a research practice partnership project

authors: Edwards, Frances

abstract: This paper outlines the affordances provided through teacher engagement in an educational research partnership project for the development of teacher self-efficacy and collective teacher efficacy. Six teachers, previously involved in a successful two-year project, chose to commit to continuing to research and develop their practice. They agreed to focus on whole class teaching which was an area of interest for their community of schools. This qualitative study utilised audio recordings of workshops, and artefacts produced by these teachers. Data was analysed thematically. Findings show there was clear evidence of growing individual and collective teacher efficacy as teachers used common language and shared and analysed student data over time. The teachers also became more prominent in their role as teacher leaders and proactive and engaged in planning for student improvement within and across their schools. Factors that contributed to teacher self-efficacy and collective efficacy were identified. Implications for teachers and schools are discussed.

text: The development of teacher self and collective efficacy through a research practice partnership project This paper outlines the affordances provided through teacher engagement in an educational research partnership project for the development of teacher self-efficacy and collective teacher efficacy. Six teachers, previously involved in a successful two-year project, chose to commit to continuing to research and develop their practice. They agreed to focus on whole class teaching which was an area of interest for their community of schools. This qualitative study utilised audio recordings of workshops, and artefacts produced by these teachers. Data was analysed thematically. Findings show there was clear evidence of growing individual and collective teacher efficacy as teachers used common language and shared and analysed student data over time. The teachers also became more prominent in their role as teacher leaders and proactive and engaged in planning for student improvement within and across their schools. Factors that contributed to teacher self-efficacy and collective efficacy were identified. Implications for teachers and schools are discussed.

year: 2025

title: Māori medical student and physician exposure to racism, discrimination, harassment, and bullying

authors: Cormack, Donna

abstract: IMPORTANCE: Discrimination, bullying, and harassment in medicine have been reported internationally, but exposures for Indigenous medical students and physicians, and for racism
specifically, remain less examined.
OBJECTIVE: To examine the prevalence of racism, discrimination, bullying, and harassment for Māori medical students and physicians in New Zealand and associations with demographic and clinical
characteristics.
DESIGN, SETTING, AND PARTICIPANTS: This cross-sectional study used data from an anonymous national survey of Māori medical students and physicians in New Zealand in late 2021 and early 2022.
Data were analyzed from March 2022 to April 2024.
EXPOSURES: Age, gender, marginalized status (ie, in addition to being Māori, belonging to other groups traditionally marginalized or underrepresented in medicine), year of medical school, year of
graduation, and main work role.
MAIN OUTCOMES AND MEASURES: Direct and witnessed racism, discrimination, bullying, and harassment were measured as any experience in the last year and ever. Any exposure to negative
comments about social groups and witnessing discriminatory treatment toward Māori patients or whānau (extended family). Considering leaving medicine, including because of mistreatment, was
measured.
RESULTS: Overall, 205 Māori medical students (median [IQR] age, 23.1 [21.6-24.3] years; 137 [67.2%] women) and 200 physicians (median [IQR] age, 36.6 [30.1-45.3] years; 123 [62.8%] women)
responded. Direct and witnessed exposure to racism (184 students [91.5%]; 176 physicians [90.7%]) and discrimination (176 students [85.9%]; 179 physicians [89.5%]) ever in medical education,
training, or work environments was common. Ever exposure to witnessed and direct bullying (123 students [66.5%]; 150 physicians [89.3%]) and harassment (73 students [39.5%]; 112 physicians
[66.7%]) was also common. Most respondents reported witnessing Māori patients or their whānau being treated badly in clinical settings, in direct interactions (67 students [57.8%]; 112 physicians
[58.9%]) or behind their backs (87 students [75.0%]; 138 physicians [72.6%]). One-quarter of Māori medical students (45 students), and 37.0%of physicians (61 physicians) had considered leaving or taken a break from medicine because of these experiences. Additional marginalized statuses were significantly associated with any direct experience of mistreatment in the last year for students and physicians. Exposure to some forms of mistreatment were also significantly associated with higher likelihood of thinking about leaving or taking a break from medicine for physicians.
CONCLUSIONS AND RELEVANCE: In this study, Māori medical students and physicians reported high exposure to multiple forms of racism, discrimination, bullying, and harassment in medical
education, training, and work environments, requiring an urgent response from medical institutions.

text: Māori medical student and physician exposure to racism, discrimination, harassment, and bullying IMPORTANCE: Discrimination, bullying, and harassment in medicine have been reported internationally, but exposures for Indigenous medical students and physicians, and for racism
specifically, remain less examined.
OBJECTIVE: To examine the prevalence of racism, discrimination, bullying, and harassment for Māori medical students and physicians in New Zealand and associations with demographic and clinical
characteristics.
DESIGN, SETTING, AND PARTICIPANTS: This cross-sectional study used data from an anonymous national survey of Māori medical students and physicians in New Zealand in late 2021 and early 2022.
Data were analyzed from March 2022 to April 2024.
EXPOSURES: Age, gender, marginalized status (ie, in addition to being Māori, belonging to other groups traditionally marginalized or underrepresented in medicine), year of medical school, year of
graduation, and main work role.
MAIN OUTCOMES AND MEASURES: Direct and witnessed racism, discrimination, bullying, and harassment were measured as any experience in the last year and ever. Any exposure to negative
comments about social groups and witnessing discriminatory treatment toward Māori patients or whānau (extended family). Considering leaving medicine, including because of mistreatment, was
measured.
RESULTS: Overall, 205 Māori medical students (median [IQR] age, 23.1 [21.6-24.3] years; 137 [67.2%] women) and 200 physicians (median [IQR] age, 36.6 [30.1-45.3] years; 123 [62.8%] women)
responded. Direct and witnessed exposure to racism (184 students [91.5%]; 176 physicians [90.7%]) and discrimination (176 students [85.9%]; 179 physicians [89.5%]) ever in medical education,
training, or work environments was common. Ever exposure to witnessed and direct bullying (123 students [66.5%]; 150 physicians [89.3%]) and harassment (73 students [39.5%]; 112 physicians
[66.7%]) was also common. Most respondents reported witnessing Māori patients or their whānau being treated badly in clinical settings, in direct interactions (67 students [57.8%]; 112 physicians
[58.9%]) or behind their backs (87 students [75.0%]; 138 physicians [72.6%]). One-quarter of Māori medical students (45 students), and 37.0%of physicians (61 physicians) had considered leaving or taken a break from medicine because of these experiences. Additional marginalized statuses were significantly associated with any direct experience of mistreatment in the last year for students and physicians. Exposure to some forms of mistreatment were also significantly associated with higher likelihood of thinking about leaving or taking a break from medicine for physicians.
CONCLUSIONS AND RELEVANCE: In this study, Māori medical students and physicians reported high exposure to multiple forms of racism, discrimination, bullying, and harassment in medical
education, training, and work environments, requiring an urgent response from medical institutions.

year: 0202-07-01