title: The engineers that time forgot

authors: Scott, Jonathan B.

subjects: engineering

abstract: You and I, dear reader of IEEE Microwave Magazine, are set to become more valuable day by day. Let me see if I can paint a picture of why.

text: The engineers that time forgot You and I, dear reader of IEEE Microwave Magazine, are set to become more valuable day by day. Let me see if I can paint a picture of why.

year: 2010

title: Does bispectral analysis of the electroencephalogram add anything but complexity?

authors: Miller, A.

subjects: anaesthesia

abstract: Background: Analysis of the bispectrum of EEG waveforms is a component of the proprietary BIS index—a commonly used commercial monitor of depth of anaesthesia. Does the use of the bispectrum give more information about depth of anaesthesia than the power spectrum? Methods: We collected and analysed EEG waveforms during induction of general anaesthesia in 39 patients, comparing the changes in bispectral parameter (SynchFastSlow), with an analogous power spectrum-based parameter (PowerFastSlow). Both compare the logarithmic ratio of high frequency components (40–47 Hz) with the total (1–47 Hz). Because the changes in bispectrum are affected by signal amplitude, we also calculated a third parameter (SFSbicoh) from the bicoherence, which is an amplitude-independent statistic. Results: The SynchFastSlow and PowerFastSlow were correlated (r=0.84) and neither was superior in predicting the awake or anaesthetized state (area under receiver operating characteristic curves = 0.85 vs 0.93). There was no change in the SFSbicoh over the induction period, and it did not correlate with SynchFastSlow (r=0.07). Conclusions: We could not show that bispectral analysis gave more information than power spectral-based analysis. Most of the changes in the bispectral values result from decreases in the relative high frequency content of the EEG caused by anaesthesia.

text: Does bispectral analysis of the electroencephalogram add anything but complexity? Background: Analysis of the bispectrum of EEG waveforms is a component of the proprietary BIS index—a commonly used commercial monitor of depth of anaesthesia. Does the use of the bispectrum give more information about depth of anaesthesia than the power spectrum? Methods: We collected and analysed EEG waveforms during induction of general anaesthesia in 39 patients, comparing the changes in bispectral parameter (SynchFastSlow), with an analogous power spectrum-based parameter (PowerFastSlow). Both compare the logarithmic ratio of high frequency components (40–47 Hz) with the total (1–47 Hz). Because the changes in bispectrum are affected by signal amplitude, we also calculated a third parameter (SFSbicoh) from the bicoherence, which is an amplitude-independent statistic. Results: The SynchFastSlow and PowerFastSlow were correlated (r=0.84) and neither was superior in predicting the awake or anaesthetized state (area under receiver operating characteristic curves = 0.85 vs 0.93). There was no change in the SFSbicoh over the induction period, and it did not correlate with SynchFastSlow (r=0.07). Conclusions: We could not show that bispectral analysis gave more information than power spectral-based analysis. Most of the changes in the bispectral values result from decreases in the relative high frequency content of the EEG caused by anaesthesia.

year: 2004

title: Piri Pāua: Mātauranga Māori and marine science approach to growth rate and length at maturity of pāua in the Bay of Plenty 2022-2024

authors: Paul-Burke, Kura

abstract: Pāua is a highly regarded taonga (culturally important) species. Mai i ngā Kurī ā Whārei ki Tihirau (the Bay of Plenty Regional Iwi Customary Fisheries Forum) raised concerns about the current state of pāua in Te Moana-a-Toi (Bay of Plenty). This project utilised localised intergenerational observations of population dynamics in traditional harvesting areas to assess pāua productivity in the Tauranga Moana Mātaitai Reserve in Tauranga and Te Rohe Moana o Ngāti Awa in Whakatāne. The project combined mātauranga Māori alongside marine science field methods.

Results were compared with previous iwi-led research at Tauranga in 2013 and Whakatāne in 2010. The pāua population in 2023 had declined by almost half in Tauranga but remained relatively consistent across all sites in Whakatāne. However, pāua were small sized in both locations, with less than 1% of individuals reaching the Minimum Legal Size (125 mm) for harvesting. Growth rate surveys were conducted in the wild at both locations from June 2023 to the end of May 2024 and identified pāua as slow growing and, as a result, sexually mature at smaller sizes than in other regions of Aotearoa New Zealand.

text: Piri Pāua: Mātauranga Māori and marine science approach to growth rate and length at maturity of pāua in the Bay of Plenty 2022-2024 Pāua is a highly regarded taonga (culturally important) species. Mai i ngā Kurī ā Whārei ki Tihirau (the Bay of Plenty Regional Iwi Customary Fisheries Forum) raised concerns about the current state of pāua in Te Moana-a-Toi (Bay of Plenty). This project utilised localised intergenerational observations of population dynamics in traditional harvesting areas to assess pāua productivity in the Tauranga Moana Mātaitai Reserve in Tauranga and Te Rohe Moana o Ngāti Awa in Whakatāne. The project combined mātauranga Māori alongside marine science field methods.

Results were compared with previous iwi-led research at Tauranga in 2013 and Whakatāne in 2010. The pāua population in 2023 had declined by almost half in Tauranga but remained relatively consistent across all sites in Whakatāne. However, pāua were small sized in both locations, with less than 1% of individuals reaching the Minimum Legal Size (125 mm) for harvesting. Growth rate surveys were conducted in the wild at both locations from June 2023 to the end of May 2024 and identified pāua as slow growing and, as a result, sexually mature at smaller sizes than in other regions of Aotearoa New Zealand.

year: 2025