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result(s) for
"Hodgson, Chris J."
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Scale appropriate modelling of diffuse microbial pollution from agriculture
by
Oliver, David M.
,
Winter, Michael
,
Chadwick, Dave R.
in
Agricultural development
,
Agricultural pollution
,
Agriculture
2009
The prediction of microbial concentrations and loads in receiving waters is a key requirement for informing policy decisions in order to safeguard human health. However, modelling the fate and transfer dynamics of faecally derived microorganisms at different spatial scales poses a considerable challenge to the research and policy community. The objective of this paper is to critically evaluate the complexities and associated uncertainties attributed to the development of models for assessing agriculturally derived microbial pollution of watercourses. A series of key issues with respect to scale appropriate modelling of diffuse microbial pollution from agriculture is presented, and these include: (1) appreciating inadequacies in baseline sampling to underpin model development; (2) uncertainty in the magnitudes of microbial pollutants attributed to different faecal sources; (3) continued development of the empirical evidence base in line with other agricultural pollutants; (4) acknowledging the value of interdisciplinary working; and (5) beginning to account for economics in model development. It is argued that uncertainty in model predictions produces a space for meaningful scrutiny of the nature of evidence and assumptions underpinning model applications around which pathways towards more effective model development may ultimately emerge.
Journal Article
Are some prepupae and pupae of male mealybugs and root mealybugs (Hemiptera, Coccoidea, Pseudococcidae and Rhizoecidae) mobile?
2013
It is hypothesised here that some mealybug (Pseudococcidae) and root mealybug (Rhizoecidae) prepupae and pupae are mobile. The prepupa and pupa of the mealybug Promyrmococcus dilli Williams and the prepupa of the root mealybug Ripersiella malschae (Williams) are described and illustrated and their probable mobility is discussed. It is also suggested that the prepupae and pupae of the mealybug Macrocepicoccus loranthi Morrison can move rapidly on the leaves when disturbed.
Journal Article
Candidate biomarkers of PARP inhibitor sensitivity in ovarian cancer beyond the BRCA genes
2018
BackgroundOlaparib (Lynparza™) is a PARP inhibitor approved for advanced BRCA-mutated (BRCAm) ovarian cancer. PARP inhibitors may benefit patients whose tumours are dysfunctional in DNA repair mechanisms unrelated to BRCA1/2. We report exploratory analyses, including the long-term outcome of candidate biomarkers of sensitivity to olaparib in BRCA wild-type (BRCAwt) tumours.MethodsTumour samples from an olaparib maintenance monotherapy trial (Study 19, D0810C00019; NCT00753545) were analysed. Analyses included classification of mutations in genes involved in homologous recombination repair (HRR), BRCA1 promoter methylation status, measurement of BRCA1 protein and Myriad HRD score.ResultsPatients with BRCAm tumours gained most benefit from olaparib; a similar treatment benefit was also observed in 21/95 patients whose tumours were BRCAwt but had loss-of-function HRR mutations compared to patients with no detectable HRR mutations (58/95). A higher median Myriad MyChoice® HRD score was observed in BRCAm and BRCAwt tumours with BRCA1 methylation. Patients without BRCAm tumours derived benefit from olaparib treatment vs placebo although to a lesser extent than BRCAm patients.ConclusionsOvarian cancer patients with tumours harbouring loss-of-function mutations in HRR genes other than BRCA1/2 may constitute a small, molecularly identifiable and clinically relevant population who derive treatment benefit from olaparib similar to patients with BRCAm.
Journal Article
Zoledronic Acid and Clinical Fractures and Mortality after Hip Fracture
by
Mesenbrink, Peter
,
Pieper, Carl F
,
Nordsletten, Lars
in
Aged
,
Aged, 80 and over
,
Biological and medical sciences
2007
Mortality is increased in the year after a hip fracture, and strategies that improve the outcome are needed. This randomized, double-blind, placebo-controlled trial compared yearly intravenous zoledronic acid with placebo first administered within 90 days after surgical repair of a hip fracture in patients who were unable or unwilling to take oral bisphosphonates. Zoledronic acid was associated with a reduced relative risk of a new clinical fracture and a reduction in mortality from all causes.
This trial compared yearly zoledronic acid with placebo after surgical repair of a hip fracture. Zoledronate was associated with a reduced relative risk of a new clinical fracture and a reduction in mortality from all causes.
Hip fractures are associated with increased morbidity, functional decline, and death in older adults, as well as increased use of health care services.
1
,
2
Mortality is increased in the year after hip fracture, with reported rates of 15 to 25% and an estimated 9 excess deaths per 100 patients among women 70 years of age or older.
2
–
10
One source of the excess morbidity and cost incurred by patients with hip fractures is new osteoporotic fractures. Such fractures occur at a rate of 10.4 per 100 patients per year, which is 2.5 times as high as the rate in age-matched . . .
Journal Article
Habitat area, quality and connectivity: striking the balance for efficient conservation
by
Hodgson, Jenny A.
,
Thomas, Chris D.
,
Moilanen, Atte
in
aggregation
,
Animal populations
,
Animal, plant and microbial ecology
2011
1. Population viability can depend on habitat area, habitat quality, the spatial arrangement of habitats (aggregations and connections) and the properties of the intervening non-breeding (matrix) land. Hodgson et al. [Journal of Applied Ecology 46 (2009) 964] and Doerr, Barrett & Doerr (Journal of Applied Ecology, 2011) disagree on the relative importance of these landscape attributes in enabling species to persist and change their distributions in response to climate change. 2. A brief review of published evidence suggests that variations in habitat area and quality have bigger effects than variations in spatial arrangement of habitats or properties of the intervening land. Even if structural features in the matrix have a measurable effect on dispersal rates, this does not necessarily lead to significant increases in population viability. 3. Large and high-quality habitats provide source populations and locations for colonisation, so they are the main determinants of the capacity of species to shift their distributions in response to climate change because populations must be established successively in each new region. 4. Synthesis and applications. Retaining as much high quality natural and semi-natural habitat as possible should remain the key focus for conservation, especially during a period of climate change.
Journal Article
The Speed of Range Shifts in Fragmented Landscapes
2012
Species may be driven extinct by climate change, unless their populations are able to shift fast enough to track regions of suitable climate. Shifting will be faster as the proportion of suitable habitat in the landscape increases. However, it is not known how the spatial arrangement of habitat will affect the speed of range advance, especially when habitat is scarce, as is the case for many specialist species. We develop methods for calculating the speed of advance that are appropriate for highly fragmented, stochastic systems. We reveal that spatial aggregation of habitat tends to reduce the speed of advance throughout a wide range of species parameters: different dispersal distances and dispersal kernel shapes, and high and low extinction probabilities. In contrast, aggregation increases the steady-state proportion of habitat that is occupied (without climate change). Nonetheless, we find that it is possible to achieve both rapid advance and relatively high patch occupancy when the habitat has a \"channeled\" pattern, resembling corridors or chains of stepping stones. We adapt techniques from electrical circuit theory to predict the rate of advance efficiently for complex, realistic landscape patterns, whereas the rate cannot be predicted by any simple statistic of aggregation or fragmentation. Conservationists are already advocating corridors and stepping stones as important conservation tools under climate change, but they are vaguely defined and have so far lacked a convincing basis in fundamental population biology. Our work shows how to discriminate properties of a landscape's spatial pattern that affect the speed of colonization (including, but not limited to, patterns like corridors and chains of stepping stones), and properties that affect a species' probability of persistence once established. We can therefore point the way to better land use planning approaches, which will provide functional habitat linkages and also maintain local population viability.
Journal Article
Conservative or liberal oxygen targets in patients on venoarterial extracorporeal membrane oxygenation
by
Totaro, Richard
,
Walsham, James
,
Totaro, Richard J
in
Extracorporeal membrane oxygenation
,
Membranes
,
Mortality
2024
PurposePatients receiving venoarterial extracorporeal membrane oxygenation (VA-ECMO) frequently develop arterial hyperoxaemia, which may be harmful. However, lower oxygen saturation targets may also lead to harmful episodes of hypoxaemia.MethodsIn this registry-embedded, multicentre trial, we randomly assigned adult patients receiving VA-ECMO in an intensive care unit (ICU) to either a conservative (target SaO2 92–96%) or to a liberal oxygen strategy (target SaO2 97–100%) through controlled oxygen administration via the ventilator and ECMO gas blender. The primary outcome was the number of ICU-free days to day 28. Secondary outcomes included ICU-free days to day 60, mortality, ECMO and ventilation duration, ICU and hospital lengths of stay, and functional outcomes at 6 months.ResultsFrom September 2019 through June 2023, 934 patients who received VA-ECMO were reported to the EXCEL registry, of whom 300 (192 cardiogenic shock, 108 refractory cardiac arrest) were recruited. We randomised 149 to a conservative and 151 to a liberal oxygen strategy. The median number of ICU-free days to day 28 was similar in both groups (conservative: 0 days [interquartile range (IQR) 0–13.7] versus liberal: 0 days [IQR 0–13.3], median treatment effect: 0 days [95% confidence interval (CI) – 3.1 to 3.1]). Mortality at day 28 (59/149 [39.6%] vs 59/151 [39.1%]) and at day 60 (64/149 [43%] vs 62/151 [41.1%] were similar in conservative and liberal groups, as were all other secondary outcomes and adverse events. The conservative group experienced 44 (29.5%) major protocol deviations compared to 2 (1.3%) in the liberal oxygen group (P < 0.001).ConclusionsIn adults receiving VA-ECMO in ICU, a conservative compared to a liberal oxygen strategy, did not affect the number of ICU-free days to day 28.
Journal Article
Climate change, connectivity and conservation decision making: back to basics
by
Hodgson, Jenny A.
,
Thomas, Chris D.
,
Moilanen, Atte
in
adaptation
,
Animal, plant and microbial ecology
,
anthropogenic activities
2009
1. The challenge of climate change forces us to re-examine the assumptions underlying conservation planning. 2. Increasing 'connectivity' has emerged as the most favoured option for conservation in the face of climate change. 3. We argue that the importance of connectivity is being overemphasized: quantifying the benefits of connectivity per se is plagued with uncertainty, and connectivity can be co-incidentally improved by targeting more concrete metrics: habitat area and habitat quality. 4. Synthesis and applications. Before investing in connectivity projects, conservation practitioners should analyse the benefits expected to arise from increasing connectivity and compare them with alternative investments, to ensure as much biodiversity conservation and resilience to climate change as possible within their budget. Strategies that we expect to remain robust in the face of climate change include maintaining and increasing the area of high quality habitats, prioritizing areas that have high environmental heterogeneity and controlling other anthropogenic threatening processes.
Journal Article
Long-term resistance to simulated climate change in an infertile grassland
by
Thompson, Ken
,
Hodgson, John G
,
Bennett, Chris R
in
Acclimatization
,
air temperature
,
Animal populations
2008
Climate shifts over this century are widely expected to alter the structure and functioning of temperate plant communities. However, long-term climate experiments in natural vegetation are rare and largely confined to systems with the capacity for rapid compositional change. In unproductive, grazed grassland at Buxton in northern England (U.K.), one of the longest running experimental manipulations of temperature and rainfall reveals vegetation highly resistant to climate shifts maintained over 13 yr. Here we document this resistance in the form of: (i) constancy in the relative abundance of growth forms and maintained dominance by long-lived, slow-growing grasses, sedges, and small forbs; (ii) immediate but minor shifts in the abundance of several species that have remained stable over the course of the experiment; (iii) no change in productivity in response to climate treatments with the exception of reduction from chronic summer drought; and (iv) only minor species losses in response to drought and winter heating. Overall, compositional changes induced by 13-yr exposure to climate regime change were less than short-term fluctuations in species abundances driven by interannual climate fluctuations. The lack of progressive compositional change, coupled with the long-term historical persistence of unproductive grasslands in northern England, suggests the community at Buxton possesses a stabilizing capacity that leads to long-term persistence of dominant species. Unproductive ecosystems provide a refuge for many threatened plants and animals and perform a diversity of ecosystem services. Our results support the view that changing land use and overexploitation rather than climate change per se constitute the primary threats to these fragile ecosystems.
Journal Article
Chronic obstructive pulmonary disease upper airway microbiome is associated with select clinical characteristics
2019
Chronic obstructive pulmonary disease (COPD) is an inflammatory lung disorder associated with lung microbiome dysbiosis. Although the upper airway microbiome is the source of the lung microbiome, the relationships between the oral, nasal, and sputum microbiota are incompletely understood. Our objective was to determine features that differentiate the oral, nasal, and sputum microbiome among subjects with stable COPD.
We recruited 15 current or former smokers to provide oral and sputum samples on day 1. On day 2, another oral sample and a nasal sample were obtained. Each sample and control underwent DNA extraction, 16S V4 rRNA amplification, 16S V4 sequencing, and qPCR of 16S rRNA. Data were analyzed using dada2 and R.
Most (14 of 15) subjects were male with a mean age of 65.2. One subject had no pulmonary obstruction, while 5 had mild COPD, 7 had moderate COPD, and 2 had severe COPD. Three subjects (20%) were current tobacco users and 2 subjects (13%) used inhaled corticosteroids (ICS). Subjects had a mean of 49.1 pack-years of tobacco exposure. Bacterial biomass was associated with anatomic site, but no differences in biomass were observed with age, FEV1 percent predicted (FEV1pp), ICS use, smoking status, or edentulous state. Shannon index was associated with site (lower nasal diversity than oral and sputum diversity, p<0.001), but not age, ICS use, FEV1pp, tobacco use, or edentulous state. β-diversity was illustrated by principal coordinate analysis using Bray-Curtis dissimilarity and PERMANOVA analyses, showing sample clustering by anatomic site (p = 0.001) with nasal samples forming a cluster separate from the combined oral wash samples and sputum samples. Clustering was also observed with ICS use (p = 0.029) and edentulous state (p = 0.019), while FEV1pp and current tobacco use were not significant. In an amplicon sequencing variant (ASV)-level analysis of oral samples using a linear regression model with Benjamini-Hochberg correction at an FDR<0.10, 10 ASVs were associated with age while no ASVs were associated with FEV1pp or smoking status. Sputum sample analysis demonstrated that 51 ASVs (25 unique genera) were associated with age, 61 ASVs (32 genera) were associated with FEV1pp, and no ASVs were associated with smoking status. In a combined dataset, the frequent exacerbator phenotype, rather than ICS use, was associated with decreased sputum Shannon diversity.
Among the upper airway microbiota of COPD subjects, anatomic site was associated with bacterial biomass, Shannon diversity, and β-diversity. ICS use and edentulous state were both associated with β-diversity. Age was associated with taxa relative abundance in oral and sputum samples, while FEV1pp was associated with taxa relative abundance in sputum samples only.
Journal Article