title: Compression and explanation using hierarchical grammars

authors: Nevill-Manning, Craig G.

subjects: computer science

abstract: Data compression is an eminently pragmatic pursuit: by removing redundancy, storage can be utilised more efficiently. Identifying redundancy also serves a less prosaic purpose-it provides cues for detecting structure, and the recognition of structure coincides with one of the goals of artificial intelligence: to make sense of the world by algorithmic means. This paper describes an algorithm that excels at both data compression and structural inference. This algorithm is implemented in a system call SEQUITUR that efficiently deals with sequences containing millions of symbols.

text: Compression and explanation using hierarchical grammars Data compression is an eminently pragmatic pursuit: by removing redundancy, storage can be utilised more efficiently. Identifying redundancy also serves a less prosaic purpose-it provides cues for detecting structure, and the recognition of structure coincides with one of the goals of artificial intelligence: to make sense of the world by algorithmic means. This paper describes an algorithm that excels at both data compression and structural inference. This algorithm is implemented in a system call SEQUITUR that efficiently deals with sequences containing millions of symbols.

year: 1996-07

title: Iron(III) complexes of the metalloligand [Pt2(μ-S)2(PPh3)4]

authors: Henderson, William

subjects: Crystal structure

abstract: Reaction of [Pt₂(μ-S)₂(PPh₃) ₄] with (NH₄)₂SO₄•FeSO ₄•6H₂O and 2 mol equivalents of picolinic acid (HPic) or 8-hydroxyquinoline (HQ) and trimethylamine base gives iron(III) adducts [Pt₂(μ-S)₂(PPh₃) ₄FePic2]+ and [Pt₂(μ-S) ₂(PPh₃)₄FeQ₂]+, isolated as hexafluorophosphate salts; these complexes are the first isolated iron(III) derivatives of [Pt₂(μ-S)₂(PPh₃) ₄]. The X-ray structure of [Pt₂(μ-S) ₂(PPh₃)₄FePic2]PF6 shows the presence of a rare distorted trigonal prismatic coordination geometry while magnetic measurements confirm the presence of high-spin iron(III) centres in the complexes.

text: Iron(III) complexes of the metalloligand [Pt2(μ-S)2(PPh3)4] Reaction of [Pt₂(μ-S)₂(PPh₃) ₄] with (NH₄)₂SO₄•FeSO ₄•6H₂O and 2 mol equivalents of picolinic acid (HPic) or 8-hydroxyquinoline (HQ) and trimethylamine base gives iron(III) adducts [Pt₂(μ-S)₂(PPh₃) ₄FePic2]+ and [Pt₂(μ-S) ₂(PPh₃)₄FeQ₂]+, isolated as hexafluorophosphate salts; these complexes are the first isolated iron(III) derivatives of [Pt₂(μ-S)₂(PPh₃) ₄]. The X-ray structure of [Pt₂(μ-S) ₂(PPh₃)₄FePic2]PF6 shows the presence of a rare distorted trigonal prismatic coordination geometry while magnetic measurements confirm the presence of high-spin iron(III) centres in the complexes.

year: 2013

title: Will access to COVID-19 vaccine in Aotearoa be equitable for priority populations?

authors: Whitehead, Jesse

abstract: AIM: This research examines the equity implications of the geographic distribution of COVID-19 vaccine delivery locations in Aotearoa New Zealand under five potential scenarios: (1) stadium mega-clinics; (2) Community Based Assessment Centres; (3) GP clinics; (4) community pharmacies; and (5) schools.
METHOD: We mapped the distribution of Aotearoa New Zealand’s population and the location of potential vaccine delivery facilities under each scenario. Geostatistical techniques identified population clusters for Māori, Pacific peoples and people aged 65 years and over. We calculated travel times between all potential facilities and each Statistical Area 1 in the country. Descriptive statistics indicate the size and proportion of populations that could face significant travel barriers when accessing COVID-19 vaccinations.
RESULTS: Several areas with significant travel times to potential vaccine delivery sites were also communities identified as having an elevated risk of COVID-19 disease and severity. All potential scenarios for vaccine delivery, with the exception of schools, resulted in travel barriers for a substantial proportion of the population. Overall, these travel time barriers disproportionately burden Māori, older communities and people living in areas of high socioeconomic deprivation.
CONCLUSION: The equitable delivery of COVID-19 vaccines is key to an elimination strategy. However, if current health services and facilities are used without well-designed and supported outreach services, then access to vaccination is likely to be inequitable.

text: Will access to COVID-19 vaccine in Aotearoa be equitable for priority populations? AIM: This research examines the equity implications of the geographic distribution of COVID-19 vaccine delivery locations in Aotearoa New Zealand under five potential scenarios: (1) stadium mega-clinics; (2) Community Based Assessment Centres; (3) GP clinics; (4) community pharmacies; and (5) schools.
METHOD: We mapped the distribution of Aotearoa New Zealand’s population and the location of potential vaccine delivery facilities under each scenario. Geostatistical techniques identified population clusters for Māori, Pacific peoples and people aged 65 years and over. We calculated travel times between all potential facilities and each Statistical Area 1 in the country. Descriptive statistics indicate the size and proportion of populations that could face significant travel barriers when accessing COVID-19 vaccinations.
RESULTS: Several areas with significant travel times to potential vaccine delivery sites were also communities identified as having an elevated risk of COVID-19 disease and severity. All potential scenarios for vaccine delivery, with the exception of schools, resulted in travel barriers for a substantial proportion of the population. Overall, these travel time barriers disproportionately burden Māori, older communities and people living in areas of high socioeconomic deprivation.
CONCLUSION: The equitable delivery of COVID-19 vaccines is key to an elimination strategy. However, if current health services and facilities are used without well-designed and supported outreach services, then access to vaccination is likely to be inequitable.

year: 2021