title: Comparison of changes in electroencephalographic measures during induction of general anaesthesia: influence of the gamma frequency band and electromyogram signal

authors: Sleigh, James W.

subjects: monitoring

abstract: Recent research has shown that high-frequency, gamma-band electroencephalographic (EEG) oscillations (40–60 Hz) may be an important marker of the conscious state. We compared the ability of the bispectral index (BIS) to distinguish the awake and anaesthetized states during the induction of general anaesthesia with: (i) components of the BIS (BetaRatio, SynchFastSlow); (ii) a new EEG variable—the median frequency of the first time derivative of the EEG signal (SE50d); and (iii) the SE50d derived from an EEG signal that has had the frequencies above 30 Hz removed (SE50d30Hz). Two groups of subjects were studied: (i) nine volunteers undergoing a short propofol infusion until loss of response to verbal command, and (ii) 84 patients undergoing routine anaesthesia for a variety of surgical procedures. In the volunteer group, the changes in the BetaRatio and SE50d were comparable with changes in the BIS. The changes in the SE50d30Hz were less consistent. In the patient group, the BIS components were equivalent to the BIS in separating the awake from the surgically anaesthetized states (area under receiver operating curve: BIS 0.95, SE50d 0.95, BetaRatio 0.96). Using the submental electromyogram (EMG) signal to estimate the frontalis EMG (30–47 Hz) signal, the changes in EMG signal were, on average, about one-tenth the magnitude of the EEG. We conclude that: (i) there exist simpler derived EEG variables that are similar in accuracy to the BIS; (ii) it is important to avoid filtering out the EEG frequencies above 30 Hz; and (iii) in most patients the confounding effects of the frontalis EMG on the EEG are minimal.

text: Comparison of changes in electroencephalographic measures during induction of general anaesthesia: influence of the gamma frequency band and electromyogram signal Recent research has shown that high-frequency, gamma-band electroencephalographic (EEG) oscillations (40–60 Hz) may be an important marker of the conscious state. We compared the ability of the bispectral index (BIS) to distinguish the awake and anaesthetized states during the induction of general anaesthesia with: (i) components of the BIS (BetaRatio, SynchFastSlow); (ii) a new EEG variable—the median frequency of the first time derivative of the EEG signal (SE50d); and (iii) the SE50d derived from an EEG signal that has had the frequencies above 30 Hz removed (SE50d30Hz). Two groups of subjects were studied: (i) nine volunteers undergoing a short propofol infusion until loss of response to verbal command, and (ii) 84 patients undergoing routine anaesthesia for a variety of surgical procedures. In the volunteer group, the changes in the BetaRatio and SE50d were comparable with changes in the BIS. The changes in the SE50d30Hz were less consistent. In the patient group, the BIS components were equivalent to the BIS in separating the awake from the surgically anaesthetized states (area under receiver operating curve: BIS 0.95, SE50d 0.95, BetaRatio 0.96). Using the submental electromyogram (EMG) signal to estimate the frontalis EMG (30–47 Hz) signal, the changes in EMG signal were, on average, about one-tenth the magnitude of the EEG. We conclude that: (i) there exist simpler derived EEG variables that are similar in accuracy to the BIS; (ii) it is important to avoid filtering out the EEG frequencies above 30 Hz; and (iii) in most patients the confounding effects of the frontalis EMG on the EEG are minimal.

year: 2001

title: Characterization of synthetic and commercial trisiloxane surfactant materials

authors: Bonnington, L. S.

subjects: organosilicone surfactant

abstract: The organosilicone surfactant Silwet L-77® (L-77), used as an agrochemical adjuvant, is a mixture comprised predominantly of [(CH₃)₃SiO]₂ (CH₃)Si (CH₂)₃ (OCH₂CH₂)n OCH₃ oligomers (n = 3-16, average n  7.5). The commercially available L-77 mixture was purified by reversed-phase high-performance liquid chromatography (HPLC) to obtain individual trisiloxane surfactant components. Pure oligomers (n = 3, 6 and 9) were also synthesized. Synthesis was achieved by hydrosilylation of monomeric ethoxylate monomethyl ether starting reagents. Pure hexa- and nona-ethylene glycols were produced by condensation of smaller oligomers. Atmospheric-pressure ionization mass spectrometry (MS) methods were used to characterize fully the commercial L-77 product and synthesized or isolated components. The application of Fourier-transform ion cyclotron resonance MS and online HPLC-electrospray ionization MS techniques to the analysis of this surfactant are described here. The application of these analytical techniques also enabled elucidation of the synthetic by-products present in the commercial formulation.

text: Characterization of synthetic and commercial trisiloxane surfactant materials The organosilicone surfactant Silwet L-77® (L-77), used as an agrochemical adjuvant, is a mixture comprised predominantly of [(CH₃)₃SiO]₂ (CH₃)Si (CH₂)₃ (OCH₂CH₂)n OCH₃ oligomers (n = 3-16, average n  7.5). The commercially available L-77 mixture was purified by reversed-phase high-performance liquid chromatography (HPLC) to obtain individual trisiloxane surfactant components. Pure oligomers (n = 3, 6 and 9) were also synthesized. Synthesis was achieved by hydrosilylation of monomeric ethoxylate monomethyl ether starting reagents. Pure hexa- and nona-ethylene glycols were produced by condensation of smaller oligomers. Atmospheric-pressure ionization mass spectrometry (MS) methods were used to characterize fully the commercial L-77 product and synthesized or isolated components. The application of Fourier-transform ion cyclotron resonance MS and online HPLC-electrospray ionization MS techniques to the analysis of this surfactant are described here. The application of these analytical techniques also enabled elucidation of the synthetic by-products present in the commercial formulation.

year: 2004

title: Taonga maioha: (Born this way) The in-depth stories of three Māori, Pasifika, and Indigenous Queens

authors: Tamuera Ariki, Paikea

abstract: Who else has the right to define these, Queens? 

This thesis provides a vital platform for the voices of three Māori, Pasifika, and Indigenous Queens, allowing them to share their transformation stories in their own words. Their experiences and feelings about in their words “being born into the wrong bodies” highlight the complex realities of identity and the struggle for acceptance by others. 

These Queens are unified in their desire for dignity and respect. Dignity and respect underscore a fundamental human right. They seek recognition in all areas of their lives, from healthcare to education, housing, employment, and beyond. By articulating their needs, they advocate for themselves and all marginalized individuals, seeking fairness and understanding within systems that often overlook them. 

Focusing on their lived experiences is crucial for fostering empathy and promoting systemic change, as it brings attention to the disparities they face and the importance of inclusivity in society. By sharing their truths, these Queens contribute to a broader dialogue about identity, respect, and the pursuit of equality for all. 

This thesis aims to illuminate the transformation stories or pūrākau of ten Māori and Pasifika Queens, to foster understanding of their unique experiences. The focus on those who identify as wahine despite being born biologically male allows the reader to highlight the rich diversity of gender identity within these cultures and groups. 

The Māori Ethics Committee granted ethics approval for the study, thereby paving the way for the Queens to tell their stories or pūrākau from their truths and perspectives. 

Taonga Maioha details the in-depth transformation stories of three Māori-Pasifika Queens aged 60 plus, supported by a contextual and cultural analysis of their generation. The voices and stories of the Queens are central to this thesis. These stories are thematically analyzed to unpack the cultural and generational influences impacting their identities. The core identity constructs of whakapapa, tinana, hinengaro, and wairua are used to frame and organize their transformation stories according to their instructions. Above all, this thesis is anchored in their rights to define themselves on the premise that they have the mana to define themselves irrespective of others who define them from the sidelines of their lives. Their definitions are theirs alone. The storytellers call themselves Queen, Wahine, or women. This is based on the assertion that it is their right to be called a Queen. In certain contexts, they may refer to themselves as takatāpui and transgender for the sake of acceptance by others. This thesis is written to enhance the mana of the storytellers. These are their stories and their truths. 

The late Dame Georgina Beyer, was one of the original participants in this thesis. Many interviews were conducted with her. Instructed by Georgina before her passing to publish elements of her story as part of this thesis. Unfortunately, the Ethics Committee at Waikato University did not accept this due to her passing. Hence, the reason ‘First Lady’ was introduced, where Liz Roberts gives exclusive details of her change, both legally and physically.

text: Taonga maioha: (Born this way) The in-depth stories of three Māori, Pasifika, and Indigenous Queens Who else has the right to define these, Queens? 

This thesis provides a vital platform for the voices of three Māori, Pasifika, and Indigenous Queens, allowing them to share their transformation stories in their own words. Their experiences and feelings about in their words “being born into the wrong bodies” highlight the complex realities of identity and the struggle for acceptance by others. 

These Queens are unified in their desire for dignity and respect. Dignity and respect underscore a fundamental human right. They seek recognition in all areas of their lives, from healthcare to education, housing, employment, and beyond. By articulating their needs, they advocate for themselves and all marginalized individuals, seeking fairness and understanding within systems that often overlook them. 

Focusing on their lived experiences is crucial for fostering empathy and promoting systemic change, as it brings attention to the disparities they face and the importance of inclusivity in society. By sharing their truths, these Queens contribute to a broader dialogue about identity, respect, and the pursuit of equality for all. 

This thesis aims to illuminate the transformation stories or pūrākau of ten Māori and Pasifika Queens, to foster understanding of their unique experiences. The focus on those who identify as wahine despite being born biologically male allows the reader to highlight the rich diversity of gender identity within these cultures and groups. 

The Māori Ethics Committee granted ethics approval for the study, thereby paving the way for the Queens to tell their stories or pūrākau from their truths and perspectives. 

Taonga Maioha details the in-depth transformation stories of three Māori-Pasifika Queens aged 60 plus, supported by a contextual and cultural analysis of their generation. The voices and stories of the Queens are central to this thesis. These stories are thematically analyzed to unpack the cultural and generational influences impacting their identities. The core identity constructs of whakapapa, tinana, hinengaro, and wairua are used to frame and organize their transformation stories according to their instructions. Above all, this thesis is anchored in their rights to define themselves on the premise that they have the mana to define themselves irrespective of others who define them from the sidelines of their lives. Their definitions are theirs alone. The storytellers call themselves Queen, Wahine, or women. This is based on the assertion that it is their right to be called a Queen. In certain contexts, they may refer to themselves as takatāpui and transgender for the sake of acceptance by others. This thesis is written to enhance the mana of the storytellers. These are their stories and their truths. 

The late Dame Georgina Beyer, was one of the original participants in this thesis. Many interviews were conducted with her. Instructed by Georgina before her passing to publish elements of her story as part of this thesis. Unfortunately, the Ethics Committee at Waikato University did not accept this due to her passing. Hence, the reason ‘First Lady’ was introduced, where Liz Roberts gives exclusive details of her change, both legally and physically.

year: 2024