Publications by authors named "Michael Storey"

21 Publications

  • Page 1 of 1

Experiments on the influence of spot fire and topography interaction on fire rate of spread.

PLoS One 2021 7;16(1):e0245132. Epub 2021 Jan 7.

School of Physical, Environmental and Mathematical Sciences, University of New South Wales (UNSW), Canberra, ACT, Australia.

Spotting is thought to increase wildfire rate of spread (ROS) and in some cases become the main mechanism for spread. The role of spotting in wildfire spread is controlled by many factors including fire intensity, number of and distance between spot fires, weather, fuel characteristics and topography. Through a set of 30 laboratory fire experiments on a 3 m x 4 m fuel bed, subject to air flow, we explored the influence of manually ignited spot fires (0, 1 or 2), the presence or absence of a model hill and their interaction on combined fire ROS (i.e. ROS incorporating main fire and merged spot fires). During experiments conducted on a flat fuel bed, spot fires (whether 1 or 2) had only a small influence on combined ROS. Slowest combined ROS was recorded when a hill was present and no spot fires were ignited, because the fires crept very slowly downslope and downwind of the hill. This was up to, depending on measurement interval, 5 times slower than ROS in the flat fuel bed experiments. However, ignition of 1 or 2 spot fires (with hill present) greatly increased combined ROS to similar levels as those recorded in the flat fuel bed experiments (depending on spread interval). The effect was strongest on the head fire, where spot fires merged directly with the main fire, but significant increases in off-centre ROS were also detected. Our findings suggest that under certain topographic conditions, spot fires can allow a fire to overcome the low spread potential of downslopes. Current models may underestimate wildfire ROS and fire arrival time in hilly terrain if the influence of spot fires on ROS is not incorporated into predictions.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0245132PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7790231PMC
January 2021

Cabozantinib for relapsed neuroblastoma: Single institution case series.

Pediatr Blood Cancer 2020 07 28;67(7):e28317. Epub 2020 Apr 28.

Division of Hematology/Oncology/Bone Marrow Transplant, Nationwide Children's Hospital, Columbus, Ohio.

Relapsed high-risk neuroblastoma has few effective therapies currently available or in development. Cabozantinib is an Food and Drug Administration approved multitargeted tyrosine kinase inhibitor for select adult malignancies with preclinical data suggesting efficacy against neuroblastoma. A safe and tolerable dose has been identified for children, but its efficacy remains unknown. We describe four children with relapsed metastatic neuroblastoma treated with cabozantinib. All four patients had extended disease control (two complete responsesfor >12 months, 2 stable disease >6 months) with manageable predictable toxicities requiring dose reduction in two patients. We discuss the potential for the use of cabozantinib in neuroblastoma.
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http://dx.doi.org/10.1002/pbc.28317DOI Listing
July 2020

Last appearance of Homo erectus at Ngandong, Java, 117,000-108,000 years ago.

Nature 2020 01 18;577(7790):381-385. Epub 2019 Dec 18.

Department of Anthropology and Museum of Natural History, University of Iowa, Iowa City, IA, USA.

Homo erectus is the founding early hominin species of Island Southeast Asia, and reached Java (Indonesia) more than 1.5 million years ago. Twelve H. erectus calvaria (skull caps) and two tibiae (lower leg bones) were discovered from a bone bed located about 20 m above the Solo River at Ngandong (Central Java) between 1931 and 1933, and are of the youngest, most-advanced form of H. erectus. Despite the importance of the Ngandong fossils, the relationship between the fossils, terrace fill and ages have been heavily debated. Here, to resolve the age of the Ngandong evidence, we use Bayesian modelling of 52 radiometric age estimates to establish-to our knowledge-the first robust chronology at regional, valley and local scales. We used uranium-series dating of speleothems to constrain regional landscape evolution; luminescence, argon/argon (Ar/Ar) and uranium-series dating to constrain the sequence of terrace evolution; and applied uranium-series and uranium series-electron-spin resonance (US-ESR) dating to non-human fossils to directly date our re-excavation of Ngandong. We show that at least by 500 thousand years ago (ka) the Solo River was diverted into the Kendeng Hills, and that it formed the Solo terrace sequence between 316 and 31 ka and the Ngandong terrace between about 140 and 92 ka. Non-human fossils recovered during the re-excavation of Ngandong date to between 109 and 106 ka (uranium-series minimum) and 134 and 118 ka (US-ESR), with modelled ages of 117 to 108 thousand years (kyr) for the H. erectus bone bed, which accumulated during flood conditions. These results negate the extreme ages that have been proposed for the site and solidify Ngandong as the last known occurrence of this long-lived species.
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http://dx.doi.org/10.1038/s41586-019-1863-2DOI Listing
January 2020

Gene Replacement Therapy: A Primer for the Health-system Pharmacist.

J Pharm Pract 2020 Dec 27;33(6):846-855. Epub 2019 Jun 27.

Department of Pharmacy, Nationwide Children's Hospital, Columbus, OH, USA.

Purpose: Comprehensive review of gene replacement therapy with guidance and expert opinion on handling and administration for pharmacists.

Summary: There are currently ∼2600 gene therapy clinical trials worldwide and 4 Food and Drug Administration (FDA)-approved gene therapy products available in the United States. Gene therapy and its handling are different from other drugs; however, there is a lack of guidance from the National Institutes of Health (NIH), FDA, Centers for Disease Control and Prevention (CDC), World Health Organization (WHO), and professional associations regarding their pharmaceutical application. Although the NIH stratifies the backbone biologicals of viral vectors in gene therapies into risk groups, incomplete information regarding minimization of exposure and reduction of risk exists. In the absence of defined guidance, individual institutions develop their own policies and procedures, which often differ and are often outdated. This review provides expert opinion on the role of pharmacists in institutional preparedness, as well as gene therapy handling and administration. A suggested infrastructural model for gene replacement therapy handling is described, including requisite equipment acquisition and standard operating procedure development. Personnel, patient, and caregiver education and training are discussed.

Conclusion: Pharmacists have a key role in the proper handling and general management of gene replacement therapies, identifying risk level, establishing infrastructure, and developing adequate policies and protocols, particularly in the absence of consensus guidelines for the handling and transport of gene replacement therapies.
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http://dx.doi.org/10.1177/0897190019854962DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7675776PMC
December 2020

Increasing optimal coagulation factor dosing in the paediatric emergency department: A quality improvement study.

Haemophilia 2019 Mar 12;25(2):258-263. Epub 2019 Feb 12.

Division of Hematology/Oncology/BMT, Nationwide Children's Hospital, Columbus, Ohio.

Introduction: Haemophilia is a disorder complicated by bleeding episodes that require emergent medical evaluation. Factor replacement dosing can present challenges for emergency department (ED) care.

Aims: We aimed to reduce out-of-range factor dosing in the ED. Specifically, we sought to increase the number of haemophilia ED patient visits between encounters where sub-optimal factor dosing was administered from a baseline of 4-15 encounters.

Methods: A chart review was completed on all patients with haemophilia A (HA) or B (HB) seen in the ED for injuries requiring factor concentrate from September 2015 to August 2016. Injuries were classified as minor-requiring a 50% factor correction or major-requiring a 100% factor correction. Optimal dosing range was defined as 90%-120% of the institutional guideline goal for the degree of injury. The predicted optimal dose range for each patient was compared to the actual dose administered.

Results: Baseline data demonstrated optimal dosing range in 70% of encounters. There was no difference between patients with HA or HB in frequency of out-of-range dosing (P = 0.15). There was no difference in frequency of out-of-range dosing between types of clotting factor concentrate used. After initiation of quality improvement (QI) interventions, we achieved 16 encounters between out-of-range dosing, exceeding our goal of 15. However, this success was not sustained.

Conclusion: Optimal coagulation factor dosing is important for patient care and resource management. QI interventions promoted increased accuracy of factor dosing for patients with haemophilia seen in the ED.
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http://dx.doi.org/10.1111/hae.13693DOI Listing
March 2019

Evidence for extremely rapid magma ocean crystallization and crust formation on Mars.

Nature 2018 06 27;558(7711):586-589. Epub 2018 Jun 27.

Centre for Star and Planet Formation and Natural History Museum of Denmark, University of Copenhagen, Copenhagen, Denmark.

The formation of a primordial crust is a critical step in the evolution of terrestrial planets but the timing of this process is poorly understood. The mineral zircon is a powerful tool for constraining crust formation because it can be accurately dated with the uranium-to-lead (U-Pb) isotopic decay system and is resistant to subsequent alteration. Moreover, given the high concentration of hafnium in zircon, the lutetium-to-hafnium (Lu-Hf) isotopic decay system can be used to determine the nature and formation timescale of its source reservoir. Ancient igneous zircons with crystallization ages of around 4,430 million years (Myr) have been reported in Martian meteorites that are believed to represent regolith breccias from the southern highlands of Mars. These zircons are present in evolved lithologies interpreted to reflect re-melted primary Martian crust , thereby potentially providing insight into early crustal evolution on Mars. Here, we report concomitant high-precision U-Pb ages and Hf-isotope compositions of ancient zircons from the NWA 7034 Martian regolith breccia. Seven zircons with mostly concordant U-Pb ages define Pb/Pb dates ranging from 4,476.3 ± 0.9 Myr ago to 4,429.7 ± 1.0 Myr ago, including the oldest directly dated material from Mars. All zircons record unradiogenic initial Hf-isotope compositions inherited from an enriched, andesitic-like crust extracted from a primitive mantle no later than 4,547 Myr ago. Thus, a primordial crust existed on Mars by this time and survived for around 100 Myr before it was reworked, possibly by impacts, to produce magmas from which the zircons crystallized. Given that formation of a stable primordial crust is the end product of planetary differentiation, our data require that the accretion, core formation and magma ocean crystallization on Mars were completed less than 20 Myr after the formation of the Solar System. These timescales support models that suggest extremely rapid magma ocean crystallization leading to a gravitationally unstable stratified mantle, which subsequently overturns, resulting in decompression melting of rising cumulates and production of a primordial basaltic to andesitic crust.
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http://dx.doi.org/10.1038/s41586-018-0222-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6107064PMC
June 2018

Age and context of the oldest known hominin fossils from Flores.

Nature 2016 06;534(7606):249-53

Centre for Archaeological Science, School of Earth &Environmental Sciences, University of Wollongong, Wollongong, New South Wales 2522, Australia.

Recent excavations at the early Middle Pleistocene site of Mata Menge in the So'a Basin of central Flores, Indonesia, have yielded hominin fossils attributed to a population ancestral to Late Pleistocene Homo floresiensis. Here we describe the age and context of the Mata Menge hominin specimens and associated archaeological findings. The fluvial sandstone layer from which the in situ fossils were excavated in 2014 was deposited in a small valley stream around 700 thousand years ago, as indicated by (40)Ar/(39)Ar and fission track dates on stratigraphically bracketing volcanic ash and pyroclastic density current deposits, in combination with coupled uranium-series and electron spin resonance dating of fossil teeth. Palaeoenvironmental data indicate a relatively dry climate in the So'a Basin during the early Middle Pleistocene, while various lines of evidence suggest the hominins inhabited a savannah-like open grassland habitat with a wetland component. The hominin fossils occur alongside the remains of an insular fauna and a simple stone technology that is markedly similar to that associated with Late Pleistocene H. floresiensis.
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http://dx.doi.org/10.1038/nature17663DOI Listing
June 2016

Revised stratigraphy and chronology for Homo floresiensis at Liang Bua in Indonesia.

Nature 2016 Apr 30;532(7599):366-9. Epub 2016 Mar 30.

Centre for Archaeological Science, School of Earth and Environmental Sciences, University of Wollongong, Wollongong, New South Wales 2522, Australia.

Homo floresiensis, a primitive hominin species discovered in Late Pleistocene sediments at Liang Bua (Flores, Indonesia), has generated wide interest and scientific debate. A major reason this taxon is controversial is because the H. floresiensis-bearing deposits, which include associated stone artefacts and remains of other extinct endemic fauna, were dated to between about 95 and 12 thousand calendar years (kyr) ago. These ages suggested that H. floresiensis survived until long after modern humans reached Australia by ~50 kyr ago. Here we report new stratigraphic and chronological evidence from Liang Bua that does not support the ages inferred previously for the H. floresiensis holotype (LB1), ~18 thousand calibrated radiocarbon years before present (kyr cal. BP), or the time of last appearance of this species (about 17 or 13-11 kyr cal. BP). Instead, the skeletal remains of H. floresiensis and the deposits containing them are dated to between about 100 and 60 kyr ago, whereas stone artefacts attributable to this species range from about 190 to 50 kyr in age. Whether H. floresiensis survived after 50 kyr ago--potentially encountering modern humans on Flores or other hominins dispersing through southeast Asia, such as Denisovans--is an open question.
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http://dx.doi.org/10.1038/nature17179DOI Listing
April 2016

Earliest hominin occupation of Sulawesi, Indonesia.

Nature 2016 Jan;529(7585):208-11

Centre for Archaeological Science, School of Earth &Environmental Sciences, University of Wollongong, Wollongong, New South Wales 2522, Australia.

Sulawesi is the largest and oldest island within Wallacea, a vast zone of oceanic islands separating continental Asia from the Pleistocene landmass of Australia and Papua (Sahul). By one million years ago an unknown hominin lineage had colonized Flores immediately to the south, and by about 50 thousand years ago, modern humans (Homo sapiens) had crossed to Sahul. On the basis of position, oceanic currents and biogeographical context, Sulawesi probably played a pivotal part in these dispersals. Uranium-series dating of speleothem deposits associated with rock art in the limestone karst region of Maros in southwest Sulawesi has revealed that humans were living on the island at least 40 thousand years ago (ref. 5). Here we report new excavations at Talepu in the Walanae Basin northeast of Maros, where in situ stone artefacts associated with fossil remains of megafauna (Bubalus sp., Stegodon and Celebochoerus) have been recovered from stratified deposits that accumulated from before 200 thousand years ago until about 100 thousand years ago. Our findings suggest that Sulawesi, like Flores, was host to a long-established population of archaic hominins, the ancestral origins and taxonomic status of which remain elusive.
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http://dx.doi.org/10.1038/nature16448DOI Listing
January 2016

Evaluation of Parenteral Nutrition Errors in an Era of Drug Shortages.

Nutr Clin Pract 2016 Apr 27;31(2):211-7. Epub 2015 Oct 27.

College of Pharmacy, The Ohio State University, Columbus, Ohio

Background: Ingredient shortages have forced many organizations to change practices or use unfamiliar ingredients, which creates potential for error. Parenteral nutrition (PN) has been significantly affected, as every ingredient in PN has been impacted in recent years.

Materials And Methods: Ingredient errors involving PN that were reported to the national anonymous MedMARx database between May 2009 and April 2011 were reviewed. Errors were categorized by ingredient, node, and severity. Categorization was validated by experts in medication safety and PN. A timeline of PN ingredient shortages was developed and compared with the PN errors to determine if events correlated with an ingredient shortage. This information was used to determine the prevalence and change in harmful PN errors during periods of shortage, elucidating whether a statistically significant difference exists in errors during shortage as compared with a control period (ie, no shortage).

Results: There were 1311 errors identified. Nineteen errors were associated with harm. Fat emulsions and electrolytes were the PN ingredients most frequently associated with error. Insulin was the ingredient most often associated with patient harm. On individual error review, PN shortages were described in 13 errors, most of which were associated with intravenous fat emulsions; none were associated with harm. There was no correlation of drug shortages with the frequency of PN errors.

Conclusion: Despite the significant impact that shortages have had on the PN use system, no adverse impact on patient safety could be identified from these reported PN errors.
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http://dx.doi.org/10.1177/0884533615608820DOI Listing
April 2016

Astronomically calibrated 40Ar/39Ar age for the Toba supereruption and global synchronization of late Quaternary records.

Proc Natl Acad Sci U S A 2012 Nov 29;109(46):18684-8. Epub 2012 Oct 29.

Quaternary Dating Laboratory, Department of Environmental, Social and Spatial Change, Roskilde University, DK-4000 Roskilde, Denmark.

The Toba supereruption in Sumatra, ∼74 thousand years (ka) ago, was the largest terrestrial volcanic event of the Quaternary. Ash and sulfate aerosols were deposited in both hemispheres, forming a time-marker horizon that can be used to synchronize late Quaternary records globally. A precise numerical age for this event has proved elusive, with dating uncertainties larger than the millennial-scale climate cycles that characterized this period. We report an astronomically calibrated (40)Ar/(39)Ar age of 73.88 ± 0.32 ka (1σ, full external errors) for sanidine crystals extracted from Toba deposits in the Lenggong Valley, Malaysia, 350 km from the eruption source and 6 km from an archaeological site with stone artifacts buried by ash. If these artifacts were made by Homo sapiens, as has been suggested, then our age indicates that modern humans had reached Southeast Asia by ∼74 ka ago. Our (40)Ar/(39)Ar age is an order-of-magnitude more precise than previous estimates, resolving the timing of the eruption to the middle of the cold interval between Dansgaard-Oeschger events 20 and 19, when a peak in sulfate concentration occurred as registered by Greenland ice cores. This peak is followed by a ∼10 °C drop in the Greenland surface temperature over ∼150 y, revealing the possible climatic impact of the eruption. Our (40)Ar/(39)Ar age also provides a high-precision calibration point for other ice, marine, and terrestrial archives containing Toba sulfates and ash, facilitating their global synchronization at unprecedented resolution for a critical period in Earth and human history beyond the range of (14)C dating.
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http://dx.doi.org/10.1073/pnas.1208178109DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3503200PMC
November 2012

Advances in on-line drinking water quality monitoring and early warning systems.

Water Res 2011 Jan 6;45(2):741-7. Epub 2010 Sep 6.

Customer Strategy and Planning, Sydney Water, Parramatta, NSW, Australia.

Significant advances have been made in recent years in technologies to monitor drinking water quality for source water protection, treatment operations, and distribution system management, in the event of accidental (or deliberate) contamination. Reports prepared through the Global Water Research Coalition (GWRC) and United States Environment Protection Agency (USEPA) agree that while many emerging technologies show promise, they are still some years from being deployed on a large scale. Further underpinning their viability is a need to interpret data in real time and implement a management strategy in response. This review presents the findings of an international study into the state of the art in this field. These results are based on visits to leading water utilities, research organisations and technology providers throughout Europe, the United States and Singapore involved in the development and deployment of on-line monitoring technology for the detection of contaminants in water.
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http://dx.doi.org/10.1016/j.watres.2010.08.049DOI Listing
January 2011

Hominins on Flores, Indonesia, by one million years ago.

Nature 2010 Apr 17;464(7289):748-52. Epub 2010 Mar 17.

Centre for Archaeological Science, School of Earth and Environmental Sciences, University of Wollongong, Wollongong, New South Wales 2522, Australia.

Previous excavations at Mata Menge and Boa Lesa in the Soa Basin of Flores, Indonesia, recovered stone artefacts in association with fossilized remains of the large-bodied Stegodon florensis florensis. Zircon fission-track ages from these sites indicated that hominins had colonized the island by 0.88 +/- 0.07 million years (Myr) ago. Here we describe the contents, context and age of Wolo Sege, a recently discovered archaeological site in the Soa Basin that has in situ stone artefacts and that lies stratigraphically below Mata Menge and immediately above the basement breccias of the basin. We show using (40)Ar/(39)Ar dating that an ignimbrite overlying the artefact layers at Wolo Sege was erupted 1.02 +/- 0.02 Myr ago, providing a new minimum age for hominins on Flores. This predates the disappearance from the Soa Basin of 'pygmy' Stegodon sondaari and Geochelone spp. (giant tortoise), as evident at the nearby site of Tangi Talo, which has been dated to 0.90 +/- 0.07 Myr ago. It now seems that this extirpation or possible extinction event and the associated faunal turnover were the result of natural processes rather than the arrival of hominins. It also appears that the volcanic and fluvio-lacustrine deposits infilling the Soa Basin may not be old enough to register the initial arrival of hominins on the island.
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http://dx.doi.org/10.1038/nature08844DOI Listing
April 2010

Nitric oxide-mediated dispersal in single- and multi-species biofilms of clinically and industrially relevant microorganisms.

Microb Biotechnol 2009 May 13;2(3):370-8. Epub 2009 Mar 13.

School of Biotechnology and Biomolecular Sciences and Centre for Marine Bio-Innovation, University of New South Wales, Sydney, NSW 2052, Australia.

Strategies to induce biofilm dispersal are of interest due to their potential to prevent biofilm formation and biofilm-related infections. Nitric oxide (NO), an important messenger molecule in biological systems, was previously identified as a signal for dispersal in biofilms of the model organism Pseudomonas aeruginosa. In the present study, the use of NO as an anti-biofilm agent more broadly was assessed. Various NO donors, at concentrations estimated to generate NO levels in the picomolar and low nanomolar range, were tested on single-species biofilms of relevant microorganisms and on multi-species biofilms from water distribution and treatment systems. Nitric oxide-induced dispersal was observed in all biofilms assessed, and the average reduction of total biofilm surface was 63%. Moreover, biofilms exposed to low doses of NO were more susceptible to antimicrobial treatments than untreated biofilms. For example, the efficacy of conventional chlorine treatments at removing multi-species biofilms from water systems was increased by 20-fold in biofilms treated with NO compared with untreated biofilms. These data suggest that combined treatments with NO may allow for novel and improved strategies to control biofilms and have widespread applications in many environmental, industrial and clinical settings.
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http://dx.doi.org/10.1111/j.1751-7915.2009.00098.xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3815757PMC
May 2009

The effects of UV disinfection on distribution pipe biofilm growth and pathogen incidence within the greater Stockholm area, Sweden.

Water Res 2007 Aug 1;41(15):3327-36. Epub 2007 May 1.

Department of Parasitology, Mycology, Water and Environmental Microbiology, Swedish Institute for Infectious Disease Control, SE-171 82 Solna, Sweden.

An assessment of the effects of the transition from conventional chlorination to UV disinfection on potable water biofilm growth and pathogen incidence was made. Two hydraulic systems were tested, one a 1.0 km polyethylene pilot-scale system within the Lovö waterworks, Stockholm, Sweden, as well as Hässelby and Nockeby municipal distribution systems within the greater Stockholm area. Biofilms were propagated on coupons and the amount of biomass analysed by standard culture and molecular methods. There was no measurable difference in biofilm biomass or pathogen incidence in the transition from conventional chlorination to UV-treatment in any system examined. With the exception of aeromonads, frank (salmonellae, enterobacteria) and opportunistic (legionellae) pathogens as well as indicator bacteria (E. coli, coliforms, enterococci) could not be detected within biofilms in either the pilot-scale or large-scale municipal system. Free-living protozoa were detected almost ubiquitously in biofilm samples in either experimental system though their exact significance and impact remains unknown and warrants further investigation.
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http://dx.doi.org/10.1016/j.watres.2007.04.024DOI Listing
August 2007

Paleocene-Eocene thermal maximum and the opening of the Northeast Atlantic.

Science 2007 Apr;316(5824):587-9

Quaternary Dating Laboratory, Department of Environment, Society and Spatial Change, Roskilde University Centre, Post Office Box 260, 4000 Roskilde, Denmark.

The Paleocene-Eocene thermal maximum (PETM) has been attributed to a sudden release of carbon dioxide and/or methane. 40Ar/39Ar age determinations show that the Danish Ash-17 deposit, which overlies the PETM by about 450,000 years in the Atlantic, and the Skraenterne Formation Tuff, representing the end of 1 +/- 0.5 million years of massive volcanism in East Greenland, are coeval. The relative age of Danish Ash-17 thus places the PETM onset after the beginning of massive flood basalt volcanism at 56.1 +/- 0.4 million years ago but within error of the estimated continental breakup time of 55.5 +/- 0.3 million years ago, marked by the eruption of mid-ocean ridge basalt-like flows. These correlations support the view that the PETM was triggered by greenhouse gas release during magma interaction with basin-filling carbon-rich sedimentary rocks proximal to the embryonic plate boundary between Greenland and Europe.
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http://dx.doi.org/10.1126/science.1135274DOI Listing
April 2007

Glycaemic index values for commercially available potatoes in Great Britain.

Br J Nutr 2005 Dec;94(6):917-21

Nutrition and Food Science Group, School of Biological and Molecular Sciences, Oxford Brookes University, Gipsy Lane Campus, Headington, Oxford OX3 0BP, UK.

The glycaemic response to eight potato varieties commercially available in Great Britain was compared against a glucose standard in a non-blind, randomised, repeated measure, crossover design trial. Seventeen healthy subjects (three males, fourteen females), mean age 32 (sd 13) years and mean BMI 22.3 (sd 3.6) kg/m2, were recruited to the study. Subjects were served portions of eight potato varieties and a standard food (glucose), on separate occasions, each containing 50 g carbohydrate. Capillary blood glucose was measured from finger-prick samples in fasted subjects (0 min) and at 15, 30, 45, 60, 90 and 120 min after the consumption of each test food. For each potato variety, the glycaemic index (GI) value was calculated geometrically by expressing the incremental area under the blood glucose curve (IAUC) as a percentage of each subject's average IAUC for the standard food. The eight potato varieties exhibited a wide range in GI values from 56 to 94. A trend was seen whereby potatoes with waxy textures produced medium GI values, whilst floury potatoes had high GI values. Considering the widespread consumption of potatoes in Great Britain (933-1086 g per person per week), this information could be used to help lower the overall GI and glycaemic load of the diets of the British population.
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http://dx.doi.org/10.1079/bjn20051571DOI Listing
December 2005

Accumulation and fate of microorganisms and microspheres in biofilms formed in a pilot-scale water distribution system.

Appl Environ Microbiol 2005 Feb;71(2):706-12

Department of Parasitology, Mycology and Water Microbiology, Swedish Institute for Infectious Disease Control, SE-171 82 Solna, Sweden.

The accumulation and fate of model microbial "pathogens" within a drinking-water distribution system was investigated in naturally grown biofilms formed in a novel pilot-scale water distribution system provided with chlorinated and UV-treated water. Biofilms were exposed to 1-mum hydrophilic and hydrophobic microspheres, Salmonella bacteriophages 28B, and Legionella pneumophila bacteria, and their fate was monitored over a 38-day period. The accumulation of model pathogens was generally independent of the biofilm cell density and was shown to be dependent on particle surface properties, where hydrophilic spheres accumulated to a larger extent than hydrophobic ones. A higher accumulation of culturable legionellae was measured in the chlorinated system compared to the UV-treated system with increasing residence time. The fate of spheres and fluorescence in situ hybridization-positive legionellae was similar and independent of the primary disinfectant applied and water residence time. The more rapid loss of culturable legionellae compared to the fluorescence in situ hybridization-positive legionellae was attributed to a loss in culturability rather than physical desorption. Loss of bacteriophage 28B plaque-forming ability together with erosion may have affected their fate within biofilms in the pilot-scale distribution system. The current study has demonstrated that desorption was one of the primary mechanisms affecting the loss of microspheres, legionellae, and bacteriophage from biofilms within a pilot-scale distribution system as well as disinfection and biological grazing. In general, two primary disinfection regimens (chlorination and UV treatment) were not shown to have a measurable impact on the accumulation and fate of model microbial pathogens within a water distribution system.
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http://dx.doi.org/10.1128/AEM.71.2.706-712.2005DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC546826PMC
February 2005

The efficacy of heat and chlorine treatment against thermotolerant Acanthamoebae and Legionellae.

Scand J Infect Dis 2004 ;36(9):656-62

Department of Parasitology, Mycology and Water Microbiology, Swedish Institute for Infectious Disease Control, SE-171 82 Solna, Sweden.

Free-living amoebae and Acanthamoebae are known to harbour a range of opportunistic microbial pathogens such as Legionellae, sequestering them from antimicrobial agents as well as environmental stresses. Less is known however of the interaction between the thermotolerant free-living amoebae and Legionellae. In the current study, such phenomena were investigated between an environmental and clinical thermotolerant Acanthamoebae isolate and 6 Legionellae; L. anisa, L. birminghamiensis, L. bozemanii, L. dumoffii, L. erythra and L. pneumophila. All Legionellae could be located within either Acanthamoeba isolate, with L. erythra, and L. pneumophila found located within vacuoles. At concentrations exceeding 2 mg/l, free chlorine was a better disinfectant than combined chlorine against Acanthamoebae-bound Legionellae, though thermal treatment was the most effective of the treatment types investigated. While the interaction with free-living Acanthamoebae increased the resistance of Legionellae to thermal treatment, it increased the sensitivity of Legionellae to free and combined chlorine. Interaction with biofilms did not affect the sensitivity of sessile and intracellular Legionellae to disinfection, caused in part by the thin coverage of biofilm on coupon surfaces. Acanthamoebae cysts remained viable after treatment with 100 mg/l chlorine (free and combined) for 10 min, as well as 80 degrees C, implying that conventional hyper-disinfection may be insufficient for long-term control of Acanthamoebae-bound Legionellae in water distribution systems.
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http://dx.doi.org/10.1080/00365540410020785DOI Listing
December 2004

Artificial groundwater treatment: biofilm activity and organic carbon removal performance.

Water Res 2004 Feb;38(3):740-8

Department of Water and Environmental Microbiology, Swedish Institute for Infectious Disease Control, Solna, S-171 82, Sweden.

The artificial recharge of sand aquifers with raw source waters is a means both explored and utilised by many water utilities to meet the future potable water demands for increasing urban populations. The microbial ecology within these systems is however, poorly understood, as is the role that microbial biofilms play in the quality of finished water. Knowledge of the ability of biofilm bacteria to metabolise natural organic matter (NOM) is limited, particularly in respect to the degradation of normally recalcitrant hydrophilic and hydrophobic humic acid fractions by sessile and planktonic microbial consortia within sand aquifer systems. To simulate the artificial recharge of sand aquifers that were proposed for the Greater Stockholm Area, four separate 4 m deep sand columns were fed raw lake water and examined over a 45-week study period. The simulated aquifer system (hydraulic retention time 9-16 h) demonstrated the removal of total organic carbon (TOC) (10+/-5%), direct total counts (DTC) of bacteria (74+/-11%), heterotrophic plate count (HPC) bacteria (87+/-5%) and assimilable organic carbon (AOC) (87+/-5%), thereby fulfilling an important barrier function, except for the removal of TOC. Hydrophilic humic acid fractions were more readily metabolised by microbiota (HPC and EUB338-positive cells) harvested from the raw source water (SSM-W), whilst hydrophobic humic acid fractions promoted higher activity by microbiota harvested from the sand matrix (SSM-S). The apparent low activity demonstrated by biofilm microbiota (approximately 40% and 25% of DTC were positive to EUB338 probing for sand matrix and slide biofilms, respectively) could be attributed to the highly recalcitrant nature of the organic loads, whilst at the same time explain the poor removal of TOC. Following nutrient activation (by the PAC assay) nonetheless, a 3-fold increase in the percentage of EUB-positive bacteria was observed on glass slides. Furthermore, the incubation of SSM-S with R2A increased probe-active cells from 57+/-8% to 75+/-7% of DTC and at the same time increased SSM-W from 38+/-8% to 50+/-10%. Whilst these results may imply a good potential for the biological treatment of water by shallow sand aquifers, further work should address the poor removal of TOC observed in this study.
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http://dx.doi.org/10.1016/j.watres.2003.10.021DOI Listing
February 2004