title: Hemicellulolytic and cellulolytic functions of the domains of a β-mannanase cloned from Caldicellosiruptor saccharolyticus

authors: Frangos, Tracy

subjects: mannanase

abstract: Various combinations of the four domains of the multifunctional mannanase from Caldicellosiruptor saccharolyticus have been cloned and expressed in Escherichia coli. The four domains comprise two catalytic domains (1 and 4), and two putative cellulose binding domains (2 and 3). Each of the six gene products (Man1, Man123, Man1234, Man23, Man234 and Man4) was partially purified by heat treatment.
The enzymes Man1234, Man123 and Man1 exhibited activity on mannans, and Man1234, Man234 and Man4 exhibited activity on xylan and carboxymethylcellulose (CMC). For the complete enzyme (Man1234) all activities were of the same order of magnitude. Activities were additive against a mixture of mannan and xylan or mannan and CMC (but not xylan and CMC). The expression product Man23 exhibited activity on none of the substrates tested, nor did its presence influence thermostability or significantly reduce the Km value for any of the substrates. However, when expressed in combination with domains 1 or 4 it greatly increased their activity.
We conclude that domain 1 catalyses mannan hydrolysis and domain 4 catalyses xylan and CMC hydrolysis at the same active site: domains 2 and 3 have no obvious function, since they do not reduce substrate Km nor affect thermostability. However, their effect on rates of substrate hydrolysis may indicate a role influencing the conformation of the adjacent catalytic domains.

text: Hemicellulolytic and cellulolytic functions of the domains of a β-mannanase cloned from Caldicellosiruptor saccharolyticus Various combinations of the four domains of the multifunctional mannanase from Caldicellosiruptor saccharolyticus have been cloned and expressed in Escherichia coli. The four domains comprise two catalytic domains (1 and 4), and two putative cellulose binding domains (2 and 3). Each of the six gene products (Man1, Man123, Man1234, Man23, Man234 and Man4) was partially purified by heat treatment.
The enzymes Man1234, Man123 and Man1 exhibited activity on mannans, and Man1234, Man234 and Man4 exhibited activity on xylan and carboxymethylcellulose (CMC). For the complete enzyme (Man1234) all activities were of the same order of magnitude. Activities were additive against a mixture of mannan and xylan or mannan and CMC (but not xylan and CMC). The expression product Man23 exhibited activity on none of the substrates tested, nor did its presence influence thermostability or significantly reduce the Km value for any of the substrates. However, when expressed in combination with domains 1 or 4 it greatly increased their activity.
We conclude that domain 1 catalyses mannan hydrolysis and domain 4 catalyses xylan and CMC hydrolysis at the same active site: domains 2 and 3 have no obvious function, since they do not reduce substrate Km nor affect thermostability. However, their effect on rates of substrate hydrolysis may indicate a role influencing the conformation of the adjacent catalytic domains.

year: 1999-08

title: Utilising risk analysis to predict post-earthquake functionality of critical healthcare facilities

authors: Boston, Megan

abstract: Hospitals, particularly emergency departments, are vital to a community’s resilience and earthquake recovery by providing emergent and ongoing critical care. Building standards and codes have higher structural requirements for hospital structures to help ensure continued functionality; nevertheless, hospitals are often damaged, evacuated or closed following design-level earthquakes. While post-earthquake hospital functionality has been the focus of recent research, it remains challenging to predict hospital functionality in a relevant and meaningful manner. Existing methods to quantify functionality are based on patient wait time, bed count, or available services. This work focuses on improving existing hospital functionality frameworks to predict various levels of hospital functionality using a combination of fault and event trees to provide a probabilistic prediction of different levels of functionality based on available services and bed counts for hospital emergency departments and whole hospitals. Fault and event trees were created using published data on hospital damage, evacuations, and operations following earthquakes and combined with international guidelines on hospital requirements and local hospital emergency procedures. The fault and event trees relate physical damage, staff shortages, and equipment failures to various hospital and emergency room functionality levels. Event trees provide a sequence of events (availability of critical staff, structural damage, and non-structural damage) leading to various levels of hospital functionality (full, partial, or not functional). Each event has an associated probability of occurring determined by a developed fault tree specific to that event failure. The methodology was validated using an additional hospital dataset to hindcast the functionality of the hospital facility. The hindcasted results match the published functionality data, indicating that this method provides a way to predict levels of functionality, which can indicate what types of services and space will be available for treatment following an earthquake.

text: Utilising risk analysis to predict post-earthquake functionality of critical healthcare facilities Hospitals, particularly emergency departments, are vital to a community’s resilience and earthquake recovery by providing emergent and ongoing critical care. Building standards and codes have higher structural requirements for hospital structures to help ensure continued functionality; nevertheless, hospitals are often damaged, evacuated or closed following design-level earthquakes. While post-earthquake hospital functionality has been the focus of recent research, it remains challenging to predict hospital functionality in a relevant and meaningful manner. Existing methods to quantify functionality are based on patient wait time, bed count, or available services. This work focuses on improving existing hospital functionality frameworks to predict various levels of hospital functionality using a combination of fault and event trees to provide a probabilistic prediction of different levels of functionality based on available services and bed counts for hospital emergency departments and whole hospitals. Fault and event trees were created using published data on hospital damage, evacuations, and operations following earthquakes and combined with international guidelines on hospital requirements and local hospital emergency procedures. The fault and event trees relate physical damage, staff shortages, and equipment failures to various hospital and emergency room functionality levels. Event trees provide a sequence of events (availability of critical staff, structural damage, and non-structural damage) leading to various levels of hospital functionality (full, partial, or not functional). Each event has an associated probability of occurring determined by a developed fault tree specific to that event failure. The methodology was validated using an additional hospital dataset to hindcast the functionality of the hospital facility. The hindcasted results match the published functionality data, indicating that this method provides a way to predict levels of functionality, which can indicate what types of services and space will be available for treatment following an earthquake.

year: 2024

title: The Digital Divide in New Zealand: The position of Māori and Pacific peoples

authors: Gibson, John

subjects: Māori digital access

abstract: Information and communication technology plays an ever-growing role in economic, political and social life and those who are unable to access such technologies are increasingly disadvantaged. Hence, what has come to be known as the ‘digital divide’ is of considerable significance. Here, indicators of that divide as it affects Māori and Pacific Islands peoples in Aotearoa/New Zealand are presented and discussed.

text: The Digital Divide in New Zealand: The position of Māori and Pacific peoples Information and communication technology plays an ever-growing role in economic, political and social life and those who are unable to access such technologies are increasingly disadvantaged. Hence, what has come to be known as the ‘digital divide’ is of considerable significance. Here, indicators of that divide as it affects Māori and Pacific Islands peoples in Aotearoa/New Zealand are presented and discussed.

year: 2002-09