Lucas Marshall - Academia.edu (original) (raw)
Papers by Lucas Marshall
The Canadian public, as well as professional providers and administrators, have retained a favour... more The Canadian public, as well as professional providers and administrators, have retained a favourable impression of the quality of health care over the last two decades, as measured in serial Health Care in Canada (HCIC) surveys. This is despite a growing perception the prevalence of excellent, or very good, health among the population has decreased; and, the reality that our aging population has a concomitantly increasing prevalence of chronic diseases, led by cardiovascular, arthritic and mental disorders. The most important contemporary care issue cited by both public and professionals is lack of timely patient access, which is also the public’s most highly rated factor in determining a sense of patient centricity in health care. To improve care, enhanced use of e-health technology, especially via the internet and electronic health records (EHR), is increasingly supported in the opinions of the majority of the public and health professionals. And, e-health implementation has a hi...
This paper reports results of the 2013-2014 Health Care in Canada survey of public (n=1000), phys... more This paper reports results of the 2013-2014 Health Care in Canada survey of public (n=1000), physician (n=101), nurse (n=100), pharmacist (n=100) and administrator (n=104) perceptions of national health, prevalence and care of chronic illnesses, compares data with previous results, and identifies preferred innovations to make future care better. We conclude the general health of the nation is decreasing; and, the burden of chronic illness is increasing. Timely access to care remains a top-of-mind issue. However, key improvement opportunities beckon, driven by pan-stakeholder valuing of increased communication, home, community and patient selfmanagement programs; and team-oriented, patient-centred care. Things can be better. Beginning in the last decade of the 20th century, the Health Care in Canada survey (HCIC) partners have repeatedly sampled public and professional perceptions around the outstanding issues and opportunities in the Canadian health universe. Principal foci of previ...
Drawing on data from 11 iterations of the Health Care in Canada (HCIC) surveys between 1998 and 2... more Drawing on data from 11 iterations of the Health Care in Canada (HCIC) surveys between 1998 and 2014, this paper summarizes trends in citizens’, physicians’, nurses’, pharmacists’ and administrators’ perceptions of the quality, access and affordability of health care in Canada, as well as innovative priorities to improve future care and predictions for its success. We found that timely access to, and affordability of, care have become the leading causes of concern in recent years among the public and health professionals alike, displacing inadequate funding and lack of professional staff, the leading causes of concern at the turn of the last century. Moreover, these issues are predicted, by all stakeholders, to likely worsen in the ensuing five years. Nonetheless, the perception among the majority of public and all professional stakeholders of the overall quality of our health system has remained relatively unchanged. In terms of priorities to improve care, increasing professional s...
Introduction Anthropogenic contaminants in surface waters have increased in complexity as the use... more Introduction Anthropogenic contaminants in surface waters have increased in complexity as the use of chemicals in all sectors of society has grown [1]. Water scarcity and quality issues will require robust, low-cost, and sustainable solutions. Biochars are particularly compelling as adsorptive solids because they repurpose wastes [2, 3] from other industries and are often carbon neutral, if not carbon negative. Cotton is the most common cellulosic fiber on the global fiber market, and as such, a significant contributor to municipal waste streams [4]. This research investigates the use of undyed, unbleached, 100% cotton muslin fabric as the fuel for making biochar to determine the feasibility of sourcing cotton fabric waste as biochar feedstock.
Journal of Addiction Medicine, 2021
OBJECTIVES The illicit drug market continuously evolves, with new substances introduced to mimic ... more OBJECTIVES The illicit drug market continuously evolves, with new substances introduced to mimic prescription or other illicit drugs while evading detection by routine drug testing. The objective was to determine if designer benzodiazepines would be present in urine samples collected from patients in various healthcare settings. METHODS Samples for which providers ordered testing for prescription benzodiazepines during the study period were diluted, subjected to enzymatic hydrolysis, and analyzed using liquid chromatography-tandem mass spectrometry. In addition to prescription benzodiazepines, samples were also analyzed for presence of any of the following designer benzodiazepines: etizolam, diclazepam, delorazepam, lormetazepam, flubromazepam, flubromazolam, and phenazepam. RESULTS Of 38,073 samples tested, 40 samples contained a designer benzodiazepine and/or a metabolite. Of the 40 samples, 19 (47.5%) also tested positive for a prescription benzodiazepine. Twenty-one samples (52.5%) did not test positive for a prescription benzodiazepine, which would result in undetected benzodiazepine use had only traditional definitive testing methods been employed. Thirty-three (82.5%) samples contained an opioid, including 22 (55%) positive for buprenorphine and/or methadone. CONCLUSIONS The potential harms from the use of designer benzodiazepines are widely unknown due to the lack of traditional pharmacokinetic studies and good manufacturing processes. Our analysis shows that when a designer benzodiazepine was present, over 80% of samples also contained an opioid or a prescription benzodiazepine, which may increase the risk of a drug interaction or adverse drug event. Providers may benefit from knowledge of their patients' designer benzodiazepine use when formulating risk mitigation strategies as part of a treatment plan.
Healthcare Quarterly, 2016
Healthcare Quarterly, 2015
Healthcare Quarterly, 2014
Precambrian Research, 2008
... Author , Kristen M. Butera a , Michael J. Rubenach a , Lucas J. Marshall a , 1 , James S. Cle... more ... Author , Kristen M. Butera a , Michael J. Rubenach a , Lucas J. Marshall a , 1 , James S. Cleverley a , b , Geordie Mark c ... 1530 Ma WilliamsNaraku Batholith in hydrothermal ore genesis, these intrusions came at the culmination of protracted metal reorganization in the crust, not ...
A paradox exists between food insecurity and obesity. Childhood obesity has tripled in the past t... more A paradox exists between food insecurity and obesity. Childhood obesity has tripled in the past three decades. This study aimed to understand the relationships between food insecurity, poverty income ratio, food stamps usage, perceived diet quality, and weight status in children. A child’s weight status is determined by many different factors and this study investigated several of these aspects. It
Geological Fieldwork, 1999
Precambrian Research, 2008
... Mark et al., 2000 G. Mark, NHS Oliver, PJ Williams, RK Valenta and RA Crookes, The evolution ... more ... Mark et al., 2000 G. Mark, NHS Oliver, PJ Williams, RK Valenta and RA Crookes, The evolution of the Ernest Henry Fe-oxide ... Brecciation within the Mary Kathleen Group of the Eastern Succession, Mt Isa Block, Australia: implications of district-scale structural and metasomatic ...
Mineralium Deposita, 2006
The source of metasomatic fluids in iron-oxidecopper-gold districts is contentious with models fo... more The source of metasomatic fluids in iron-oxidecopper-gold districts is contentious with models for magmatic and other fluid sources having been proposed. For this study, δ 18 O and δ 13 C ratios were measured from carbonate mineral separates in the Proterozoic eastern Mt Isa Block of Northwest Queensland, Australia. Isotopic analyses are supported by petrography, mineral chemistry and cathodoluminescence imagery. Marine meta-carbonate rocks (ca. 20.5‰ δ 18 O and 0.5‰ δ 13 C calcite) and graphitic meta-sedimentary rocks (ca. 14‰ δ 18 O and −18‰ δ 13 C calcite) are the main supracrustal reservoirs of carbon and oxygen in the district. The isotopic ratios for calcite from the cores of Na-(Ca) alteration systems strongly cluster around 11‰ δ 18 O and −7‰ δ 13 C, with shifts towards higher δ 18 O values and higher and lower δ 13 C values, reflecting interaction with different hostrocks. Na-(Ca)-rich assemblages are out of isotopic equilibrium with their metamorphic hostrocks, and isotopic values are consistent with fluids derived from or equilibrated with igneous rocks. However, igneous rocks in the eastern Mt Isa Block contain negligible carbon and are incapable of buffering the δ 13 C signatures of CO 2-rich metasomatic fluids associated with Na-(Ca) alteration. In contrast, plutons in the eastern Mt Isa Block have been documented as having exsolved saline CO 2-rich fluids and represent the most probable fluid source for Na-(Ca) alteration. Intrusion-proximal, skarn-like Cu-Au orebodies that lack significant K and Fe enrichment (e.g. Mt Elliott) display isotopic ratios that cluster around values of 11‰ δ 18 O and −7‰ δ 13 C (calcite), indicating an isotopically similar fluid source as for Na-(Ca) alteration and that significant fluidwallrock interaction was not required in the genesis of these deposits. In contrast, K-and Fe-rich, intrusion-distal deposits (e.g. Ernest Henry) record significant shifts in δ 18 O and δ 13 C towards values characteristic of the broader hostrocks to the deposits, reflecting fluid-wallrock equilibration before mineralisation. Low temperature, low salinity, low δ 18 O (<10‰ calcite) and CO 2-poor fluids are documented in retrograde metasomatic assemblages, but these fluids are paragenetically late and have not contributed significantly to the mass budgets of Cu-Au mineralisation.
Journal of Geochemical Exploration, 2003
Abrupt pore pressure changes accompanying faulting can compete with, or locally predominate over,... more Abrupt pore pressure changes accompanying faulting can compete with, or locally predominate over, thermal gradients, in their capacity to transfer mass in deep hydrothermal systems. Differential mass transfer at 1-to >1000-m scales in the mesothermal Cloncurry Fe oxide-Cu-Au district of northern Australia was apparently controlled by pore pressure cycling around dilatant parts of shear and fault zones. Geochemical reaction modelling of pore pressure drops in fluids initially equilibrated with altered wallrocks in the Cloncurry district produces model vein assemblages that mimic those observed in the field, whereas temperature-drop scenarios fail to replicate these veins.
The Canadian public, as well as professional providers and administrators, have retained a favour... more The Canadian public, as well as professional providers and administrators, have retained a favourable impression of the quality of health care over the last two decades, as measured in serial Health Care in Canada (HCIC) surveys. This is despite a growing perception the prevalence of excellent, or very good, health among the population has decreased; and, the reality that our aging population has a concomitantly increasing prevalence of chronic diseases, led by cardiovascular, arthritic and mental disorders. The most important contemporary care issue cited by both public and professionals is lack of timely patient access, which is also the public’s most highly rated factor in determining a sense of patient centricity in health care. To improve care, enhanced use of e-health technology, especially via the internet and electronic health records (EHR), is increasingly supported in the opinions of the majority of the public and health professionals. And, e-health implementation has a hi...
This paper reports results of the 2013-2014 Health Care in Canada survey of public (n=1000), phys... more This paper reports results of the 2013-2014 Health Care in Canada survey of public (n=1000), physician (n=101), nurse (n=100), pharmacist (n=100) and administrator (n=104) perceptions of national health, prevalence and care of chronic illnesses, compares data with previous results, and identifies preferred innovations to make future care better. We conclude the general health of the nation is decreasing; and, the burden of chronic illness is increasing. Timely access to care remains a top-of-mind issue. However, key improvement opportunities beckon, driven by pan-stakeholder valuing of increased communication, home, community and patient selfmanagement programs; and team-oriented, patient-centred care. Things can be better. Beginning in the last decade of the 20th century, the Health Care in Canada survey (HCIC) partners have repeatedly sampled public and professional perceptions around the outstanding issues and opportunities in the Canadian health universe. Principal foci of previ...
Drawing on data from 11 iterations of the Health Care in Canada (HCIC) surveys between 1998 and 2... more Drawing on data from 11 iterations of the Health Care in Canada (HCIC) surveys between 1998 and 2014, this paper summarizes trends in citizens’, physicians’, nurses’, pharmacists’ and administrators’ perceptions of the quality, access and affordability of health care in Canada, as well as innovative priorities to improve future care and predictions for its success. We found that timely access to, and affordability of, care have become the leading causes of concern in recent years among the public and health professionals alike, displacing inadequate funding and lack of professional staff, the leading causes of concern at the turn of the last century. Moreover, these issues are predicted, by all stakeholders, to likely worsen in the ensuing five years. Nonetheless, the perception among the majority of public and all professional stakeholders of the overall quality of our health system has remained relatively unchanged. In terms of priorities to improve care, increasing professional s...
Introduction Anthropogenic contaminants in surface waters have increased in complexity as the use... more Introduction Anthropogenic contaminants in surface waters have increased in complexity as the use of chemicals in all sectors of society has grown [1]. Water scarcity and quality issues will require robust, low-cost, and sustainable solutions. Biochars are particularly compelling as adsorptive solids because they repurpose wastes [2, 3] from other industries and are often carbon neutral, if not carbon negative. Cotton is the most common cellulosic fiber on the global fiber market, and as such, a significant contributor to municipal waste streams [4]. This research investigates the use of undyed, unbleached, 100% cotton muslin fabric as the fuel for making biochar to determine the feasibility of sourcing cotton fabric waste as biochar feedstock.
Journal of Addiction Medicine, 2021
OBJECTIVES The illicit drug market continuously evolves, with new substances introduced to mimic ... more OBJECTIVES The illicit drug market continuously evolves, with new substances introduced to mimic prescription or other illicit drugs while evading detection by routine drug testing. The objective was to determine if designer benzodiazepines would be present in urine samples collected from patients in various healthcare settings. METHODS Samples for which providers ordered testing for prescription benzodiazepines during the study period were diluted, subjected to enzymatic hydrolysis, and analyzed using liquid chromatography-tandem mass spectrometry. In addition to prescription benzodiazepines, samples were also analyzed for presence of any of the following designer benzodiazepines: etizolam, diclazepam, delorazepam, lormetazepam, flubromazepam, flubromazolam, and phenazepam. RESULTS Of 38,073 samples tested, 40 samples contained a designer benzodiazepine and/or a metabolite. Of the 40 samples, 19 (47.5%) also tested positive for a prescription benzodiazepine. Twenty-one samples (52.5%) did not test positive for a prescription benzodiazepine, which would result in undetected benzodiazepine use had only traditional definitive testing methods been employed. Thirty-three (82.5%) samples contained an opioid, including 22 (55%) positive for buprenorphine and/or methadone. CONCLUSIONS The potential harms from the use of designer benzodiazepines are widely unknown due to the lack of traditional pharmacokinetic studies and good manufacturing processes. Our analysis shows that when a designer benzodiazepine was present, over 80% of samples also contained an opioid or a prescription benzodiazepine, which may increase the risk of a drug interaction or adverse drug event. Providers may benefit from knowledge of their patients' designer benzodiazepine use when formulating risk mitigation strategies as part of a treatment plan.
Healthcare Quarterly, 2016
Healthcare Quarterly, 2015
Healthcare Quarterly, 2014
Precambrian Research, 2008
... Author , Kristen M. Butera a , Michael J. Rubenach a , Lucas J. Marshall a , 1 , James S. Cle... more ... Author , Kristen M. Butera a , Michael J. Rubenach a , Lucas J. Marshall a , 1 , James S. Cleverley a , b , Geordie Mark c ... 1530 Ma WilliamsNaraku Batholith in hydrothermal ore genesis, these intrusions came at the culmination of protracted metal reorganization in the crust, not ...
A paradox exists between food insecurity and obesity. Childhood obesity has tripled in the past t... more A paradox exists between food insecurity and obesity. Childhood obesity has tripled in the past three decades. This study aimed to understand the relationships between food insecurity, poverty income ratio, food stamps usage, perceived diet quality, and weight status in children. A child’s weight status is determined by many different factors and this study investigated several of these aspects. It
Geological Fieldwork, 1999
Precambrian Research, 2008
... Mark et al., 2000 G. Mark, NHS Oliver, PJ Williams, RK Valenta and RA Crookes, The evolution ... more ... Mark et al., 2000 G. Mark, NHS Oliver, PJ Williams, RK Valenta and RA Crookes, The evolution of the Ernest Henry Fe-oxide ... Brecciation within the Mary Kathleen Group of the Eastern Succession, Mt Isa Block, Australia: implications of district-scale structural and metasomatic ...
Mineralium Deposita, 2006
The source of metasomatic fluids in iron-oxidecopper-gold districts is contentious with models fo... more The source of metasomatic fluids in iron-oxidecopper-gold districts is contentious with models for magmatic and other fluid sources having been proposed. For this study, δ 18 O and δ 13 C ratios were measured from carbonate mineral separates in the Proterozoic eastern Mt Isa Block of Northwest Queensland, Australia. Isotopic analyses are supported by petrography, mineral chemistry and cathodoluminescence imagery. Marine meta-carbonate rocks (ca. 20.5‰ δ 18 O and 0.5‰ δ 13 C calcite) and graphitic meta-sedimentary rocks (ca. 14‰ δ 18 O and −18‰ δ 13 C calcite) are the main supracrustal reservoirs of carbon and oxygen in the district. The isotopic ratios for calcite from the cores of Na-(Ca) alteration systems strongly cluster around 11‰ δ 18 O and −7‰ δ 13 C, with shifts towards higher δ 18 O values and higher and lower δ 13 C values, reflecting interaction with different hostrocks. Na-(Ca)-rich assemblages are out of isotopic equilibrium with their metamorphic hostrocks, and isotopic values are consistent with fluids derived from or equilibrated with igneous rocks. However, igneous rocks in the eastern Mt Isa Block contain negligible carbon and are incapable of buffering the δ 13 C signatures of CO 2-rich metasomatic fluids associated with Na-(Ca) alteration. In contrast, plutons in the eastern Mt Isa Block have been documented as having exsolved saline CO 2-rich fluids and represent the most probable fluid source for Na-(Ca) alteration. Intrusion-proximal, skarn-like Cu-Au orebodies that lack significant K and Fe enrichment (e.g. Mt Elliott) display isotopic ratios that cluster around values of 11‰ δ 18 O and −7‰ δ 13 C (calcite), indicating an isotopically similar fluid source as for Na-(Ca) alteration and that significant fluidwallrock interaction was not required in the genesis of these deposits. In contrast, K-and Fe-rich, intrusion-distal deposits (e.g. Ernest Henry) record significant shifts in δ 18 O and δ 13 C towards values characteristic of the broader hostrocks to the deposits, reflecting fluid-wallrock equilibration before mineralisation. Low temperature, low salinity, low δ 18 O (<10‰ calcite) and CO 2-poor fluids are documented in retrograde metasomatic assemblages, but these fluids are paragenetically late and have not contributed significantly to the mass budgets of Cu-Au mineralisation.
Journal of Geochemical Exploration, 2003
Abrupt pore pressure changes accompanying faulting can compete with, or locally predominate over,... more Abrupt pore pressure changes accompanying faulting can compete with, or locally predominate over, thermal gradients, in their capacity to transfer mass in deep hydrothermal systems. Differential mass transfer at 1-to >1000-m scales in the mesothermal Cloncurry Fe oxide-Cu-Au district of northern Australia was apparently controlled by pore pressure cycling around dilatant parts of shear and fault zones. Geochemical reaction modelling of pore pressure drops in fluids initially equilibrated with altered wallrocks in the Cloncurry district produces model vein assemblages that mimic those observed in the field, whereas temperature-drop scenarios fail to replicate these veins.