801 results on '"David Hopkins"'
Search Results
202. Cardiovascular risk factors and metabolic syndrome in people with established psychotic illnesses: baseline data from the IMPaCT randomized controlled trial
- Author
-
Khalida Ismail, Fiona Gaughran, Ruth Ohlsen, Robin M. Murray, Kathryn Greenwood, S Smith, David Hopkins, Anita Patel, Catherine Fung, Poonam Gardner-Sood, IMPaCT team, John Lally, Anthony S. David, Evangelos Papanastasiou, Oluwadamilola Onagbesan, Jonas Eberhard, Conan O'Brien, Zerrin Atakan, A Keen, and Daniel Stahl
- Subjects
Gerontology ,medicine.medical_specialty ,Population ,Prevalence ,Type 2 diabetes ,law.invention ,Randomized controlled trial ,law ,Internal medicine ,Medicine ,education ,National Cholesterol Education Program ,Applied Psychology ,education.field_of_study ,business.industry ,Original Articles ,psychotic disorder ,severe mental illnesses ,medicine.disease ,Metabolic syndrome ,Obesity ,schizophrenia ,Psychiatry and Mental health ,business ,physical health ,Body mass index - Abstract
BackgroundThe aims of the study were to determine the prevalence of cardiometabolic risk factors and establish the proportion of people with psychosis meeting criteria for the metabolic syndrome (MetS). The study also aimed to identify the key lifestyle behaviours associated with increased risk of the MetS and to investigate whether the MetS is associated with illness severity and degree of functional impairment.MethodBaseline data were collected as part of a large randomized controlled trial (IMPaCT RCT). The study took place within community mental health teams in five Mental Health NHS Trusts in urban and rural locations across England. A total of 450 randomly selected out-patients, aged 18–65 years, with an established psychotic illness were recruited. We ascertained the prevalence rates of cardiometabolic risk factors, illness severity and functional impairment and calculated rates of the MetS, using International Diabetes Federation (IDF) and National Cholesterol Education Program Third Adult Treatment Panel criteria.ResultsHigh rates of cardiometabolic risk factors were found. Nearly all women and most men had waist circumference exceeding the IDF threshold for central obesity. Half the sample was obese (body mass index ≥ 30 kg/m2) and a fifth met the criteria for type 2 diabetes mellitus. Females were more likely to be obese than males (61% v. 42%, p < 0.001). Of the 308 patients with complete laboratory measures, 57% (n = 175) met the IDF criteria for the MetS.ConclusionsIn the UK, the prevalence of cardiometabolic risk factors in individuals with psychotic illnesses is much higher than that observed in national general population studies as well as in most international studies of patients with psychosis.
- Published
- 2015
- Full Text
- View/download PDF
203. BILL OVERTON, with ELAINE HOBBY and JAMES MCLAVERTY (eds). The Collected Verse of John, Lord Hervey (1696-1743)
- Author
-
David Hopkins
- Subjects
Linguistics and Language ,History ,Literature and Literary Theory ,Theology ,Hobby ,Language and Linguistics ,Classics - Published
- 2017
- Full Text
- View/download PDF
204. Inside interesting integrals by Paul J. Nahin, pp. 436, £28 (paperback), ISBN 978-1-49391-276-6, Springer Verlag (2015)
- Author
-
David Hopkins
- Subjects
General Mathematics - Published
- 2016
- Full Text
- View/download PDF
205. Intravitreal aflibercept compared with panretinal photocoagulation for proliferative diabetic retinopathy: the CLARITY non-inferiority RCT
- Author
-
Beverley White-Alao, Sobha Sivaprasad, Jayashree Ramu, David Hopkins, Joanna Kelly, Seow Tien Yeo, Caroline Murphy, Rhiannon Tudor Edwards, A Toby Prevost, James W B Bainbridge, Joana C. Vasconcelos, Amy Riddell, Philip Hykin, and National Institute for Health Research
- Subjects
medicine.medical_specialty ,education.field_of_study ,business.industry ,Cost effectiveness ,lcsh:R ,Population ,lcsh:Medicine ,Diabetic retinopathy ,medicine.disease ,law.invention ,03 medical and health sciences ,0302 clinical medicine ,Clinical research ,Randomized controlled trial ,Clinical trials unit ,law ,Pro re nata ,Internal medicine ,030221 ophthalmology & optometry ,medicine ,030212 general & internal medicine ,education ,business ,Aflibercept ,medicine.drug - Abstract
Background Panretinal photocoagulation (PRP) has been the standard of care for patients with proliferative diabetic retinopathy (PDR) for the last 40 years. It prevents severe visual loss in PDR but is also associated with adverse effects on visual functions. Objectives The clinical efficacy and mechanistic evaluation of aflibercept for proliferative diabetic retinopathy (CLARITY) trial evaluated the clinical efficacy, mechanisms and cost-effectiveness of intravitreal aflibercept (Eylea®, Regeneron, Tarrytown, NY, USA/Bayer Pharma AG, Berlin, Germany therapy for PDR. Design A multicentre, prospective, individually randomised, single-masked, active-controlled trial with concurrent economic evaluation that tested the non-inferiority of intravitreal aflibercept versus standard care PRP at 52 weeks. A subset of the participants enrolled in a mechanistic evaluation substudy. Setting 22 UK NHS clinical sites. Participants Patients aged at least 18 years having either treatment-naive PDR or active retinal neovascularisation (NV) despite prior PRP requiring treatment and best corrected visual acuity (BCVA) of 54 Early Treatment Diabetic Retinopathy Study (ETDRS) letters or better in the study eye were included. Eyes with evidence of macular oedema at baseline confirmed by central subfield thickness > 320 µm on spectral-domain optical coherence tomography were excluded. Intervention In the intervention arm, intravitreal aflibercept injections were given at baseline, 4 and 8 weeks and patients were subsequently reviewed every month and injected pro re nata based on the treatment response defined by degree of regression of retinal NV. In the comparator arm, PRP was completed in 2-weekly sessions and then supplemented if necessary at 8-weekly intervals. Main outcome measures The primary outcome was the mean change in BCVA at 52 weeks utilising a linear mixed-effects model incorporating data from both week 12 and week 52. Results A total of 232 participants (116 per arm) were recruited between August 2014 and November 2015. A total of 221 and 210 participants contributed to the intention-to-treat (ITT) model and per-protocol (PP) analysis, respectively. Economic evaluation was undertaken on 202 participants (101 per arm) with complete cost and outcome data. Aflibercept was non-inferior and superior to PRP in both the ITT population [mean BCVA difference 3.9 letters, 95% confidence interval (CI) 2.3 to 5.6 letters; p p Limitations This study is limited to 1 year of follow-up. Conclusions At an additional cost, the study shows that intravitreal aflibercept is an effective alternative treatment option for PDR in the first year. Future work Future research is needed to evaluate the long-term benefits of aflibercept in comparison with PRP and other anti-vascular endothelial growth factor agents for this condition. Trial registration Current Controlled Trials ISRCTN32207582. Funding This project was funded by the National Institute for Health Research (NIHR) Efficacy and Mechanistic Evaluation programme, a Medical Research Council and NIHR partnership. Aflibercept was supplied by Bayer Plc (Reading, UK). The study was sponsored by NIHR Moorfields Biomedical Research Centre and supported by the UK Clinical Research Network. The research was supported by the NIHR Biomedical Research Centre at Moorfields Eye Hospital NHS Foundation Trust and University College London Institute of Ophthalmology, the NIHR Moorfields Clinical Research Facility and the UK Clinical Reasearch Collaboration-registered King’s Clinical Trials Unit at King’s Health Partners, which is partly funded by the NIHR Biomedical Research Centre for Mental Health at South London and Maudsley NHS Foundation Trust and King’s College London.
- Published
- 2018
206. Responses to increases in temperature of heterotrophic micro-organisms in soils from the maritime Antarctic
- Author
-
Anthony G. O'Donnell, David Hopkins, Vito Armando Laudicina, Iain P. Hartley, Kevin K. Newsham, Steven Rushton, Paul G. Dennis, Luigi Badalucco, Sun Benhua, Laudicina, V., Benhua, S., Dennis, P., Badalucco, L., Rushton, S., Newsham, K., O’Donnell, A., Hartley, I., and Hopkins, D.
- Subjects
Soil organic matter ,Ecology ,Settore AGR/13 - Chimica Agraria ,Mineralization (soil science) ,Soil carbon ,Biology ,Soil respiration ,chemistry.chemical_compound ,Carbon dioxide ,Agricultural and Biological Sciences (all) ,chemistry ,Thermal ,Environmental chemistry ,Respiration ,Soil water ,sense organs ,General Agricultural and Biological Sciences ,Respiration rate ,Acclimation - Abstract
Understanding relationships between environmental changes and soil microbial respiration is critical for predicting changes in soil organic carbon (SOC) fluxes and content. The maritime Antarctic is experiencing one of the fastest rates of warming in the world and is therefore a key location to examine the effect of temperature on SOC mineralization by the respiration of soil micro-organisms. However, depletion of the labile substrates at higher temperatures relative to the total SOC and greater temperature sensitivity of recalcitrant components of the SOC confound simple interpretations of the effects of warming. We have addressed these issues by testing the hypothesis that respiration by heterotrophic soil micro-organisms is not down-regulated with increasing temperature by comparing the increase in biomass-specific respiration rate with temperature to the increase in respiration rate per unit SOC. We used five soils from the maritime Antarctic ranging in latitude and SOC content and measured the soil respiratory responses to temperatures ranging from 2 to 50 °C in laboratory incubations lasting up to 31 days. In all cases, soil respiration increased with temperature up to 50 °C, even though this exceeds the temperatures normally be experienced, indicating that the community contained sufficient physiological diversity to be able to respire over large temperature ranges. Both the biomass-specific respiration rate and the overall rate of SOC mineralization increased with temperature, which we interpret as respiration by soil micro-organisms not down-regulating relative to temperature.
- Published
- 2015
- Full Text
- View/download PDF
207. Relationship between 1:5 Soil/Water and Saturated Paste Extract Sodium Adsorption Ratios by Three Extraction Methods
- Author
-
David E. Clay, Yangbo He, David Hopkins, Douglas A. Wysocki, and Thomas M. DeSutter
- Subjects
Calcite ,chemistry.chemical_compound ,Adsorption ,Chromatography ,chemistry ,Sodium ,Environmental chemistry ,Extraction (chemistry) ,Soil water ,Soil Science ,chemistry.chemical_element ,Extraction methods - Published
- 2015
- Full Text
- View/download PDF
208. The Process of Adaptation Following a New Diagnosis of Type 1 Diabetes in Adulthood: A Meta-Synthesis
- Author
-
Mette Due-Christensen, David Hopkins, Vibeke Zoffmann, Angus Forbes, and Ingrid Willaing
- Subjects
Adult ,Adaptive strategies ,adulthood ,diagnosis ,Health Behavior ,030209 endocrinology & metabolism ,adaptation ,03 medical and health sciences ,0302 clinical medicine ,Orientation (mental) ,Diabetes mellitus ,Adaptation, Psychological ,medicine ,Habitus ,Humans ,030212 general & internal medicine ,Adaptation (computer science) ,Qualitative Research ,Type 1 diabetes ,meta-synthesis ,Public Health, Environmental and Occupational Health ,Middle Aged ,medicine.disease ,Europe ,Diabetes Mellitus, Type 1 ,North America ,qualitative ,lived experience ,Psychology ,Psychosocial ,qualitative research ,Clinical psychology ,Qualitative research - Abstract
While Type 1 diabetes (T1D) is generally associated with childhood, half of all cases occur in adulthood. The adaptive strategies individuals employ during the initial adaptive phase may have an important impact on their risk of future diabetes complications and their psychosocial well-being. We conducted a systematic review of six databases and included nine qualitative studies in a meta-synthesis, the aims of which were to develop a better understanding of how adults newly diagnosed with T1D experience the diagnosis and the phenomena associated with the early process of adaptation to life with diabetes. The meta-synthesis identified five constructs that shaped and influenced the early adaptive process: disruption, constructing a personal view of diabetes, reconstructing a view of self, learning to live with diabetes, and behavioral adaptations. The adaptive processes of adults to a diabetes diagnosis are highly referenced to prior life experiences, social habitus, and psychological orientation.
- Published
- 2017
- Full Text
- View/download PDF
209. Hyperprolactinaemia in first episode psychosis:A longitudinal assessment
- Author
-
Kathryn Greenwood, Marco Colizzi, Fiona Gaughran, Poonam Gardner-Sood, Sara Fraietta, Elena Carra, Zerrin Atakan, Oliver D. Howes, Olesya Ajnakina, John Lally, S Smith, Hugh R J Williams, David Taylor, David Hopkins, Valeria Mondelli, Khalida Ismail, Robin M. Murray, and Brendon Stubbs
- Subjects
Adult ,Male ,medicine.medical_specialty ,Psychosis ,endocrine system ,Time Factors ,Adolescent ,medicine.medical_treatment ,Stress ,03 medical and health sciences ,Young Adult ,0302 clinical medicine ,Internal medicine ,First episode psychosis (FEP) ,medicine ,Antipsychotics ,Hyperprolactinaemia ,Prolactin ,Schizophrenia ,Humans ,Amisulpride ,Longitudinal Studies ,Young adult ,Antipsychotic ,Biological Psychiatry ,Risperidone ,Psychopathology ,Middle Aged ,medicine.disease ,030227 psychiatry ,Antipsychotic Agents ,Female ,Hyperprolactinemia ,Psychotic Disorders ,Psychiatry and Mental health ,Endocrinology ,Psychology ,030217 neurology & neurosurgery ,hormones, hormone substitutes, and hormone antagonists ,medicine.drug - Abstract
Little is known about hyperprolactinaemia (HPL) in first episode psychosis (FEP) patients. We investigated longitudinal changes in serum prolactin in FEP, and the relationship between HPL, and antipsychotic medication and stress. Serum prolactin was recorded in FEP patients at recruitment and again, 3 and 12 months later. HPL was defined as a serum prolactin level > 410 mIU/L (~ 19.3 ng/ml) for males, and a serum prolactin level > 510 mIU/L (~ 24.1 ng/ml) for females. From a total of 174 people with serum prolactin measurements at study recruitment, 43% (n = 74) had HPL, whilst 27% (n = 21/78) and 27% (n = 26/95) had HPL at 3 and 12 months respectively. We observed higher serum prolactin levels in females versus males (p < 0.001), and in antipsychotic treated (n = 68) versus antipsychotic naïve patients (p < 0.0001). Prolactin levels were consistently raised in FEP patients taking risperidone, amisulpride and FGAs compared to other antipsychotics. No significant relationship was observed between perceived stress scores (β = 7.13, t = 0.21, df = 11, p = 0.0.84 95% CI − 72.91–87.16), or objective life stressors (β = − 21.74, t = − 0.31, df = 8, p = 0.77 95% CI − 218.57–175.09) and serum prolactin. Our study found elevated rates of HPL over the course of the first 12 months of illness. We found no evidence to support the notion that stress is related to elevated serum prolactin at the onset of psychosis.
- Published
- 2017
- Full Text
- View/download PDF
210. WITHDRAWN: Introduction
- Author
-
David Hopkins
- Subjects
Food Science - Published
- 2017
- Full Text
- View/download PDF
211. Carbon and macronutrient losses during accelerated erosion under different tillage and residue management
- Author
-
Martin J. Shipitalo, David Hopkins, F. S. Jones, Jennifer A.J. Dungait, Elizabeth A. Dayton, Joshua W. Beniston, A. Joynes, and Rattan Lal
- Subjects
Tillage ,No-till farming ,Crop residue ,Conventional tillage ,chemistry ,Agronomy ,Phosphorus ,Soil organic matter ,Erosion ,Soil Science ,Environmental science ,chemistry.chemical_element ,Soil carbon - Abstract
Summary There have been many studies on the effects of tillage on erosional losses from soil, but rarely have soil organic carbon (SOC), nitrogen (N) and phosphorus (P) losses been quantified simultaneously during a single erosion event. We applied a simulated rainfall event (70 mm hour−1) to plots within a gently sloping field (6%) in Ohio, USA, on which maize (C4) cultivation had replaced C3 vegetation several decades earlier. The plots were under different tillage management: (i) no till (NT100) for 42 years; (ii) NT100 plots from which 50% (NT50) or (iii) 100% (NT0) of crop residues were removed annually for 8 years; (iv) NT100 plots tilled 24 hours previously (TNT); and (v) conventional tillage (CT) for 28 years. Relationships between SOC, N and P concentrations and natural abundance 13C : 15N stable isotope values in the topsoils and sediments suggested that eroded SOC and TN were associated with the erosion of soil organic matter, whilst P losses were driven by the transport of the mineral fraction. Stable 13C isotope analyses revealed that tillage and residue removal both increased the proportion of older (C3), rather than new (C4, maize-derived), SOC in eroded sediments. This study therefore demonstrated that a single tillage event after 42 years of continuous no-till caused larger erosional fluxes than 8 years of continuous removal of all maize residues, and that long-term conventional tillage resulted in the loss of a greater amount of older (> 28 years) SOC in eroded sediments, compared with continuous NT management.
- Published
- 2014
- Full Text
- View/download PDF
212. David Quint. InsideParadise Lost: Reading the Designs of Milton's Epic. x + 329pp. Princeton, NJ and Oxford: Princeton UP, 2014. ISBN 13: 9780691161914 $95.00/£65.00 (cloth); ISBN 13: 9780691159744 $35.00/£24.95 (paper)
- Author
-
David Hopkins
- Subjects
History ,Paradise lost ,Literature and Literary Theory ,Reading (process) ,media_common.quotation_subject ,Art history ,EPIC ,media_common - Published
- 2014
- Full Text
- View/download PDF
213. The English Enlightenment Reads Ovid: Dryden and Jacob Tonson's 1717 ‘Metamorphoses’. By Richard Morton. Pp. xxix + 166. New York: AMS Press, 2013. Hb. $82.50. Ovid in English, 1480–1625, Part 1: ‘Metamorphoses’. Edited by Sarah Annes Brown and Andrew Taylor. (MHRA Tudor and Stuart Translations). Pp. xi + 238. London: Modern Humanities Research Association, 2013. Hb. £29.99, pb. £14.99
- Author
-
David Hopkins
- Subjects
Linguistics and Language ,Literature and Literary Theory ,Philosophy ,media_common.quotation_subject ,Enlightenment ,Language and Linguistics ,Classics ,media_common - Published
- 2014
- Full Text
- View/download PDF
214. Spatial mapping of evapotranspiration over Devils Lake basin with SEBAL: application to flood mitigation via irrigation of agricultural crops
- Author
-
R. Gautam, Byron Clark, David Hopkins, Dean D. Steele, Sheldon R. Tuscherer, and Bryan Thoreson
- Subjects
Hydrology ,Crop coefficient ,Center pivot irrigation ,Soil survey ,SEBAL ,Irrigation ,Evapotranspiration ,Irrigation scheduling ,Soil Science ,Environmental science ,Flood mitigation ,Agronomy and Crop Science ,Water Science and Technology - Abstract
Excessive precipitation since 1993 has produced extensive flooding in the Devils Lake basin in northeastern North Dakota, USA. Irrigation of agricultural crops has been proposed as a flood mitigation tool. Ten test fields were equipped with center pivot irrigation systems to compare test field evapotranspiration (ET) with ET for crops in the predominantly nonirrigated basin. An irrigation scheduling analysis indicated 2006 was a favorable year to estimate the maximum ET gains achievable via irrigation. An ET map for 2006 using the Surface Energy Balance Algorithm for Land (SEBAL) for 54 % of the basin, and land use and soil survey data, was used to compare ET estimates at the test fields with ET estimates across the study area. May–September ET was estimated by SEBAL as 394 mm for wheat and 435 mm for corn across the study area, while corn ET at irrigated test sites was 452 mm. Because the 17-mm ET advantage by irrigating corn was substantially smaller than the 41-mm ET advantage for corn versus wheat, we conclude widespread irrigation development to mitigate flooding is not justified. Coarse-textured soils exhibited some seasonal ET deficits, but their small areal extents and parcel sizes offer virtually no opportunity for flood mitigation.
- Published
- 2014
- Full Text
- View/download PDF
215. Temperature sensitivity of soil respiration rates enhanced by microbial community response
- Author
-
Jens-Arne Subke, Jennifer A.J. Dungait, Iain P. Hartley, Norma Salinas, Andrew T. Nottingham, Brajesh K. Singh, Göran Bergkvist, Philip A. Wookey, Maria-Teresa Sebastià, Kristiina Karhu, F. Gouriveau, Göran I. Ågren, Marc D. Auffret, James I. Prosser, Patrick Meir, and David Hopkins
- Subjects
010504 meteorology & atmospheric sciences ,Nitrogen ,Soil science ,Global Warming ,complex mixtures ,01 natural sciences ,Feedback ,Soil respiration ,Soil ,chemistry.chemical_compound ,Respiration ,Ecosystem ,Soil Microbiology ,0105 earth and related environmental sciences ,2. Zero hunger ,Tropical Climate ,Multidisciplinary ,Arctic Regions ,Climate-change ecology ,Temperature ,Soil chemistry ,04 agricultural and veterinary sciences ,Soil carbon ,Carbon Dioxide ,Biogeochemistry ,15. Life on land ,Cold Climate ,Carbon ,Oxygen ,chemistry ,Microbial population biology ,13. Climate action ,Environmental chemistry ,Carbon dioxide ,Soil water ,040103 agronomy & agriculture ,0401 agriculture, forestry, and fisheries ,Environmental science - Abstract
Soils store about four times as much carbon as plant biomass1, and soil microbial respiration releases about 60 petagrams of carbon per year to the atmosphere as carbon dioxide2. Short-term experiments have shown that soil microbial respiration increases exponentially with temperature3. This information has been incorporated into soil carbon and Earth-system models, which suggest that warming-induced increases in carbon dioxide release from soils represent an important positive feedback loop that could influence twenty-first-century climate change4. The magnitude of this feedback remains uncertain, however, not least because the response of soil microbial communities to changing temperatures has the potential to either decrease5,6,7 or increase8,9 warming-induced carbon losses substantially. Here we collect soils from different ecosystems along a climate gradient from the Arctic to the Amazon and investigate how microbial community-level responses control the temperature sensitivity of soil respiration. We find that the microbial community-level response more often enhances than reduces the mid- to long-term (90 days) temperature sensitivity of respiration. Furthermore, the strongest enhancing responses were observed in soils with high carbon-to-nitrogen ratios and in soils from cold climatic regions. After 90 days, microbial community responses increased the temperature sensitivity of respiration in high-latitude soils by a factor of 1.4 compared to the instantaneous temperature response. This suggests that the substantial carbon stores in Arctic and boreal soils could be more vulnerable to climate warming than currently predicted. This work was carried out with Natural Environment Research Council (NERC) funding (grant number NE/H022333/1). K.K. was supported by an Academy of Finland post-doctoral research grant while finalizing this manuscript. P.M. was supported by ARC FT110100457 and NERC NE/G018278/1, and B.K.S by the Grain Research and Development Corporation and ARC DP130104841.
- Published
- 2014
- Full Text
- View/download PDF
216. Long-term irrigation effects on soil organic matter under temperate grazed pasture
- Author
-
Leo M. Condron, David Hopkins, Steven A. Wakelin, Edward G. Gregorich, and Amanda Black
- Subjects
Irrigation ,geography ,geography.geographical_feature_category ,Agronomy ,Soil organic matter ,Soil water ,Bulk soil ,Soil Science ,Growing season ,Environmental science ,Soil carbon ,Water content ,Pasture - Abstract
Summary Irrigation of grazed pasture significantly increases plant and animal production, which may in turn increase soil organic carbon (SOC), depending on the balance between primary production and below-ground allocation of C on the one hand, and the decomposition and export of C from the soil on the other. To evaluate the effect of irrigation on SOC we sampled a grazed pasture field experiment maintained under different irrigation treatments for 62 years. The dry-land treatment in this experiment only received rainfall at an average of 740 mm year−1. The 10 and 20% irrigation treatments involved application of 100 mm of irrigation when the soil reached 10 and 20% gravimetric moisture content, respectively. The 10 and 20% irrigation treatments received average total annual irrigation inputs of 260 and 770 mm year−1, respectively. The 10 and 20% irrigation treatments increased pasture production by 44 and 74%, respectively, compared with that from the dry-land. Analysis of soils taken to 1-m depth revealed that amounts of SOC were not significantly different between the dry-land (125.5 Mg ha−1) and 10% irrigation (117.8 Mg ha−1) treatments, but these were significantly greater than the 20% irrigation treatment (93.0 Mg ha−1). At 50–100 cm, SOC was also less (34%) for the 20% irrigation treatment than for the 10% irrigation treatment. The relative quantities of carbon (C) and nitrogen (N) in the light fraction (LF) at all soil depths decreased successively from dry-land to the 20% irrigation treatment, suggesting that wetter soil conditions accelerated decomposition of the LF fraction, a comparatively labile SOC fraction. The C-to-N ratio of the bulk soil was also less for the 20% irrigation treatment, indicating more decomposed SOM in the irrigated than in the dry-land treatment. There were no significant differences in the microbial biomass between the three different irrigation treatments, but the respiration rate (CO2 production) of soil organisms in the 20% irrigation treatment was consistently greater than in the other two treatments. It was concluded that large increases in plant productivity as a result of irrigation had either no effect or significantly reduced SOC stocks under grazed pasture. The reduced SOC content observed in the 20% irrigation treatment was attributed to a combination of increased C losses in animal products and drainage associated with greater stocking, together with accelerated decomposition of organic C resulting from elevated soil moisture maintained throughout the growing season.
- Published
- 2014
- Full Text
- View/download PDF
217. Dr Leavis's Seventeenth Century
- Author
-
David Hopkins
- Subjects
Literature and Literary Theory ,Philosophy - Published
- 2014
- Full Text
- View/download PDF
218. Legacy Effects of Oil Road Reclamation on Soil Biology and Plant Community Composition
- Author
-
Amy C. Ganguli, David Hopkins, Laura F. Gentry, Eric M. Viall, and Peter D. Stahl
- Subjects
Ecology ,Soil biodiversity ,Soil biology ,Soil organic matter ,Plant community ,Nutrient ,Land reclamation ,Environmental protection ,Environmental science ,Soil fertility ,Energy source ,Ecology, Evolution, Behavior and Systematics ,Nature and Landscape Conservation - Abstract
Following the unprecedented oil drilling presently occurring in western North Dakota, thousands of kilometers of oil roads must be reclaimed to an acceptable post-extraction condition. This study assessed the soil biological and plant communities of nine decommissioned oil roads reclaimed during three periods between 1983 and 2002 in the Little Missouri National Grasslands of western North Dakota. We hypothesized that time-since-reclamation would positively affect soil biological and plant communities and, consequently, success of reclamation at older sites. To assess this hypothesis, we measured soil enzyme activity, soil microbial community composition, plant community composition, and soil physical and chemical properties along a gradient extending from road-center to adjacent native prairie for the nine roads. Time-since-reclamation did not affect soil and plant properties measured, indicating that older reclamations are not more similar to native prairie than reclamations occurring more recently. A strong gradient between samples from road-center and native prairie was identified with univariate and ordination analyses, indicating that soil and plant communities of reclaimed oil roads do not resemble those of the surrounding prairie. Soil organic matter (SOM) was identified as the most significantly affected soil property, being 30% lower on reclaimed roads than prairie. The relationship between SOM, microbial community, and plant community suggests that incorporating additional SOM could hasten reclamation as a result of improving the physical environment for plants and providing a labile carbon and energy source for the soil microbial community which, in turn, will enhance the nutrient and physical conditions for plant growth.
- Published
- 2014
- Full Text
- View/download PDF
219. Concise calculus by Sheng Gong, pp. 674, £48 (paper), ISBN 978-9-81429-149-1, World Scientific Publishing Co (2017)
- Author
-
David Hopkins
- Subjects
General Mathematics ,Philosophy ,Calculus ,medicine ,Scientific publishing ,medicine.disease ,Calculus (medicine) - Published
- 2018
- Full Text
- View/download PDF
220. A left-sided cerebrospinal fluid hydrothorax and a right ventricular-peritoneal shunt: a unique clinical case study
- Author
-
David Hopkins, Rhian Jones, Avinash Aujayeb, and Stewart Pattman
- Subjects
medicine.medical_specialty ,Pleural effusion ,Hydrothorax ,Conservative Treatment ,Ventriculoperitoneal Shunt ,Left sided ,Asymptomatic ,03 medical and health sciences ,0302 clinical medicine ,Cerebrospinal fluid ,Rare Disease ,Humans ,Medicine ,030212 general & internal medicine ,Aged, 80 and over ,Frailty ,business.industry ,General Medicine ,medicine.disease ,Shunt (medical) ,Pleural Effusion ,030228 respiratory system ,Effusion ,Female ,Radiology ,Neurosurgery ,medicine.symptom ,business - Abstract
We describe the case of a 84-year-old woman with a right ventricular-peritoneal shunt and a left-sided pleural effusion, the analysis of which was positive for cerebrospinal fluid. We consider the potential causative mechanisms. Our patient was managed conservatively due to her frailty, the effusion being asymptomatic and her preference not to pursue further invasive diagnostic testing. This case report is unique due to the contralateral nature of the effusion to the shunt, which has not been described before in the literature.
- Published
- 2019
- Full Text
- View/download PDF
221. Meat Quality : Genetic and Environmental Factors
- Author
-
PhD, Wieslaw Przybylski, PhD, David Hopkins, PhD, Wieslaw Przybylski, and PhD, David Hopkins
- Subjects
- Meat--Quality, Meat industry and trade--Quality
- Abstract
One of the biggest challenges faced by meat producers today is the requirement to improve the quality of meat while maintaining focus on efficiency and higher yields. Numerous studies have shown that consumers are willing to pay premiums for meat products with guaranteed eating quality. This book examines the complicated multistep process of produc
- Published
- 2016
222. Biogeochemical responses to nutrient, moisture and temperature manipulations of soil from Signy Island, South Orkney Islands in the Maritime Antarctic
- Author
-
Kevin K. Newsham, Paul G. Dennis, Stephen P Rushton, David Hopkins, V.J. Ord, Anthony G. O'Donnell, Sun Benhua, Vito Armando Laudicina, Sun, B, Dennis, PG, Laudicina, VA, Ord, VJ, Rushton, SP, O'Donnel, AG, Newsham, KK, and Hopkins, DW
- Subjects
Biogeochemical cycle ,Moisture ,Chemistry ,Settore AGR/13 - Chimica Agraria ,carbon mineralization, nitrogen mineralization, organic substrates, soil respiration, warming, water addition ,Geology ,Mineralization (soil science) ,Oceanography ,Soil respiration ,Nutrient ,Environmental chemistry ,Botany ,Respiration ,Cycling ,Nitrogen cycle ,Ecology, Evolution, Behavior and Systematics - Abstract
We have investigated how the microbially-driven processes of carbon (C) mineralization (respiration) and nitrogen (N) mineralization/immobilization in a soil from the northern Maritime Antarctic respond to differences in water availability (20% and 80% water-holding capacity) and temperature (5°C and 15°C) in the presence and absence of different organic substrates (2 mg C as either glucose, glycine or tryptone soy broth (TSB) powder (a complex microbial growth medium)) in a controlled laboratory experiment over 175 days. Soil respiration and N mineralization/immobilization in the presence of a C-rich substrate (glucose) increased with increases in water and temperature. These factors were influential individually and had an additive effect when applied together. For the N-rich substrates (glycine and TSB), microbial responses to increased water or temperature alone were weak or not significant, but these factors interacted to give significantly positive increases when applied together. These data indicate that under the expected changes in environmental conditions in the Maritime Antarctic, where temperature and the availability of water and organic substrates will probably increase, soil microbial activity will lead to more rapid C and N cycling and have a positive feedback on these biogeochemical processes, particularly where or when these factors increase concurrently.
- Published
- 2014
- Full Text
- View/download PDF
223. Microbial properties and nitrogen contents of arable soils under different tillage regimes
- Author
-
Benhua Sun, Paul G. Dennis, Tim J. Daniell, Sandra Caul, Paul D. Hallett, David Hopkins, and David Roberts
- Subjects
Biomass (ecology) ,Conventional tillage ,business.product_category ,Chemistry ,Soil Science ,Soil carbon ,Pollution ,Minimum tillage ,Plough ,Tillage ,No-till farming ,Agronomy ,Soil water ,business ,Agronomy and Crop Science - Abstract
Attention is being paid to the use of different tillage regimes as a means of retaining soil organic carbon (SOC) and sequestering more SOC. Alongside earlier measurements of total SOC stocks under different tillage regimes, we have examined the distribution of nitrogen (N), microbial activity and the structure of the soil bacterial community from differently tilled plots under continuous barley. The plots were established 5 yr before sampling and have been maintained annually under conventional tillage (CT; moldboard ploughing to 20 cm and disking), deep ploughing (DP; ploughing to 40 cm and disking), minimum tillage (MT; disking to 7 cm) or zero tillage (ZT). Our earlier work showed there was no difference in SOC contents down to 60-cm depth between the treatments, but now we report that there were significant differences in the total N and active microbial biomass (substrateinduced respiration) contents of the same soils. The N contents of the CT, DP and MT treatments were not significantly different, but the ZT contained significantly more N, indicating either greater N retention under the ZT treatment or preferential loss from the more intensively tilled treatments, or a combination of both. The microbial biomass content was greater for the CT and DP treatments than for the MT and ZT treatments, indicating greater sensitivity to treatment effects of the microbial biomass pool than the total C pool, consistent with its more dynamic nature. Terminal restriction fragment length polymorphism (T-RFLP) analyses of the soil bacteria DNA (a method of assessing the bacterial community structure) enabled the samples to be distinguished both according to SOC content, which is to be expected, and to tillage regime with the greatest differences in community structure occurring in the ZT treatment and the least in DP and CT treatments, reflecting the degree of homogenization or disturbance resulting from tillage.
- Published
- 2013
- Full Text
- View/download PDF
224. Simultaneous down-regulation of enzymes in the phenylpropanoid pathway of plants has aggregated effects on rhizosphere microbial communities
- Author
-
E. L. Tilston, David Hopkins, and Claire Halpin
- Subjects
chemistry.chemical_classification ,Rhizosphere ,Phenylpropanoid ,Cinnamyl-alcohol dehydrogenase ,fungi ,food and beverages ,Soil Science ,Biomass ,Fatty acid ,Biology ,Microbiology ,chemistry.chemical_compound ,Enzyme ,Microbial population biology ,chemistry ,Botany ,Caffeic acid ,Agronomy and Crop Science - Abstract
We have investigated the effects of genetic modifications to lignin biosynthesis in tobacco on the structural and functional characteristics of the microbial community in the rhizospheres of plants with down-regulations to cinnamyl alcohol dehydrogenase (CAD), caffeic acid O-methyltransferase (COMT) and cinnamoyl-CoA reductase (CCR) singly and in all the double and triple combinations, and corresponding unmodified plants. The mass of root produced was reduced by the down-regulation of enzymes in the phenylpropanoid pathway, but there were no differences in the microbial biomass in the rhizosphere per mass of roots. The composition of the rhizosphere microbial communities differed between modified and unmodified plants, with the modified plants having smaller proportions of fungal biomass as indicated by phospholipid fatty acid. Subtle changes to both root chemistry and rhizosphere microbial community function associated with down-regulation of CAD have the potential to modify carbon cycling processes.
- Published
- 2013
- Full Text
- View/download PDF
225. Acid hydrolysis to define a biologically-resistant pool is compromised by carbon loss and transformation
- Author
-
L.G. Greenfield, Leo M. Condron, C. van Kessel, H. Henry Janzen, Jeff Baldock, Michael H. Beare, Edward G. Gregorich, Peter W. Clinton, David Hopkins, Stefan J. Hill, and Sharon A. Billings
- Subjects
De novo synthesis ,Hydrolysis ,Chemistry ,Soil organic matter ,Soil water ,Soil Science ,Organic chemistry ,chemistry.chemical_element ,Fraction (chemistry) ,Acid hydrolysis ,Microbiology ,Carbon ,Incubation - Abstract
Biologically-resistant carbon (C) comprises the bulk of C in most soils and is often estimated from chemical separation of a soil organic matter (SOM) fraction that is not hydrolysed by strong acid, and exhibits an older radiocarbon age and slower turnover than the whole SOM. Here we examine the effects of acid hydrolysis – the method used to separate the nonhydrolysable C – on the quantity, structure and isotopic makeup of C in pure model carbohydrates and those contained in senescent maize that resemble C inputs to SOM. We demonstrate that significant alterations occur during hydrolysis resulting in C mass losses (up to 75% preferential loss of 13C) and de novo synthesis of nonhydrolysable, 13C-depleted material dominated by aromatic > alkyl > carbonyl moieties. We infer that similar losses, and transformations of 14C, would partly explain the greater ages attributed to the chemically resistant C, seriously impairing the use of acid hydrolysis to identify this pool of SOM and that de novo synthesis during hydrolysis has obfuscated the true chemical nature of the nonhydrolysable fraction of SOM.
- Published
- 2013
- Full Text
- View/download PDF
226. The age of CO2 released from soils in contrasting ecosystems during the arctic winter
- Author
-
Martin Sommerkorn, Philip A. Wookey, Iain P. Hartley, David Hopkins, and Mark H. Garnett
- Subjects
14CO2 ,Ecology ,food and beverages ,Soil Science ,Climate change ,tundra-heath ,tree-line ,Microbiology ,Tundra ,Soil respiration ,mountain birch ,Vegetation type ,Soil water ,radiocarbon ,Environmental science ,Ecosystem ,Arctic vegetation ,passive sampling ,Tree line ,winter respiration - Abstract
In arctic ecosystems, winter soil respiration can contribute substantially to annual CO2 release, yet the source of this C is not clear. We analysed the 14C content of C released from plant-free plots in mountain birch forest and tundra-heath. Winter-respired CO2 was found to be a similar age (tundra) or older (forest) than C released during the previous autumn. Overall, our study demonstrates that the decomposition of older C can continue during the winter, in these two contrasting arctic ecosystems.
- Published
- 2013
- Full Text
- View/download PDF
227. Microbial responses to the erosional redistribution of soil organic carbon in arable fields
- Author
-
Blair M. McKenzie, David Hopkins, Jennifer A.J. Dungait, John S. Rowan, Claire Ghee, Cathy Hawes, Elizabeth Dixon, and Eric Paterson
- Subjects
Nutrient ,Deposition (aerosol physics) ,Soil water ,Erosion ,Soil Science ,Sediment ,Environmental science ,Soil science ,Soil carbon ,Microbiology ,Nitrogen cycle ,Carbon cycle - Abstract
Quantifying the potential for eroding agricultural soils to act as sinks or sources of atmospheric carbon relies on accounting for the pools and fluxes of soil organic carbon (SOC) and nutrients, e.g. nitrogen (N), affected by erosion. Herein, we report the outcomes of an experiment where a C 4 maize ( Zea mays ) crop ( δ 13 C = −12.1‰) was cultivated and incorporated for 2 years to introduce a ‘pulse’ of 13 C-enriched SOC to a C 3 arable soil ( δ 13 C = −27.4‰). Soils were sampled at eroding (top slope and upper slope) and depositional (lower slope and slope foot) positions of an accelerated erosion pathway that were confirmed using 137 Cs measurements. The sand particle-sized fraction (63–2000 μm) was predominant and increased in the depositional slope positions due to selective loss of fine particles and preferential deposition of the coarsest fraction of transported sediment. There was a significant isometric relationship between the percentage SOC and total N: top slope > upper slope > lower slope, with similar values in the slope foot to the top slope. The δ 15 N values of the soils were enriched (7.3‰) at the slope foot, compared with the other slope positions (average 6.3‰), suggesting increased denitrification rates. The δ 13 C values of the soil microbial biomass C extracted from surface soils (0–5 cm) at each slope position showed that the proportion of maize C being incorporated into the soil microbial biomass declined in the downslope direction from 54% (top slope) to 43% (upper slope) to 18% (lower slope) in inverse proportion to the size of the soil microbial biomass, and increased to 41% at the slope foot. This suggests dynamic replacement of the SOC with crop C in the eroding slope positions and dilution of the transported C by C3-SOC in the depositional slope positions. This paper is evidence that erosional distribution of soil carbon leads to differential microbial utilisation of SOC between eroding and depositional sites.
- Published
- 2013
- Full Text
- View/download PDF
228. Sources of Vitamin A in the Diets of Pre-School Children in the Avon Longitudinal Study of Parents and Children (ALSPAC)
- Author
-
Kate Northstone, Victoria L. Cribb, David Hopkins, and Pauline M Emmett
- Subjects
Vitamin ,Adult ,Parents ,Longitudinal study ,030309 nutrition & dietetics ,nutrient-poor foods ,medicine.medical_treatment ,lcsh:TX341-641 ,core and non-core foods ,Diet Records ,Article ,vitamin A ,Nutrient density ,carotene ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Nutrient ,medicine ,nutrient-dense foods ,Humans ,030212 general & internal medicine ,Food science ,Longitudinal Studies ,2. Zero hunger ,0303 health sciences ,Nutrition and Dietetics ,business.industry ,Carotene ,pre-school children ,Retinol ,Feeding Behavior ,ALSPAC ,Carotenoids ,3. Good health ,Diet ,chemistry ,Quartile ,Child, Preschool ,Dietary Supplements ,business ,Energy Intake ,lcsh:Nutrition. Foods and food supply ,Food Science ,retinol - Abstract
Vitamin A is essential for growth and development. We investigated whether high consumption of energy-dense nutrient-poor foods in the diets of pre-school children is detrimental to diet quality with respect to vitamin A. Data were collected from 755 children at 18-months and 3½-years, from the Avon Longitudinal Study of Parents and Children, using 3-day unweighed dietary records completed by parents in 1994 and 1996, respectively. Energy, carotene and retinol intakes were calculated. The quality of the diet declined from 18-months to 3½-years with respect to vitamin A. Preformed retinol intakes decreased by −54 μg/day on average (p = 0.003). Carotene intakes were similar at each age although there was a 23% increase in energy intake by 3½-years. Longitudinally those in the highest quartile of intake at 18-months were twice as likely to remain in the highest quartile at 3½-years for retinol (OR 2.21 (95% CI 1.48–3.28)) and carotene (OR 1.66 (95% CI 1.11–2.50)) than to change quartiles. Nutrient-rich core foods provided decreasing amounts of carotene and preformed retinol over time (both p <, 0.001). Vegetables and milk contributed the highest proportion of carotene at both ages, but milk’s contribution decreased over time. Milk and liver were the largest sources of retinol. Nutrient-poor foods provided an increased proportion of energy (p <, 0.001) with low proportions of both nutrients, however fat spreads made an important contribution. It is recommended that pre-school children should take vitamin supplements, only 19% at 18-months did this, falling to 11% at 3½-years. Care should be taken to choose nutrient-rich foods and avoid energy-dense, nutrient-poor foods when feeding pre-school children.
- Published
- 2013
229. ARTS OF RESISTANCE AND REMEMBRANCE * Classics and Translation: Essays by D. S. Carne-Ross. Edited by KENNETH HAYNES
- Author
-
David Hopkins
- Subjects
History ,Literature and Literary Theory ,Political economy ,Art history ,Resistance (creativity) ,The arts - Published
- 2013
- Full Text
- View/download PDF
230. Evapotranspiration mapping with metric to evaluate effectiveness of irrigation in flood mitigation for the Devils Lake Basin
- Author
-
Sheldon R. Tuscherer, David Hopkins, Xinhua Jia, Dean D. Steele, Hakan Büyükcangaz, Uludağ Üniversitesi/Biyosistem Mühendisliği Bölümü., Büyükcangaz, Hakan, and AAH-2934-2021
- Subjects
Agricultural crops ,SEBAL ,Coefficients ,010504 meteorology & atmospheric sciences ,Mitigation ,0208 environmental biotechnology ,Agricultural engineering ,METRIC ,Effluents ,02 engineering and technology ,Eddy covariance ,Flood mitigation strategies ,01 natural sciences ,Landsat 5 ,Landsat-5 ,Water supply ,Agricultural land ,Evapotranspiration ,Flood mitigation ,Precipitation assessment ,Drainage ,Waterlogging ,Drainage network ,Devils lake ,Irrigation system ,Corn ,Satellite imagery ,Forestry ,Agriculture ,Remote sensing ,North dakota ,Fluxes ,Mapping ,Calibration ,Rainfed agriculture ,Waterlogging (agriculture) ,Medicago sativa ,Irrigation ,Remote Sensing ,Latent Heat Flux ,Crop Coefficient ,Biomedical Engineering ,Soil Science ,Crops ,Poorly drained soils ,Subsurface drainage ,Mean absolute error ,0105 earth and related environmental sciences ,Hydrology ,United states ,Groundwater flow ,Alfalfa ,Tm ,Evapotranspiration mapping ,Floods ,020801 environmental engineering ,Flood control ,Sebal model ,Lakes ,Land use ,Environmental science ,Soil moisture ,Energy balance algorithm ,Agronomy and Crop Science ,Food Science - Abstract
A period of excess precipitation since 1993 in the Devils Lake basin in northeastern North Dakota has caused extensive flooding of agricultural land and has raised the question of whether irrigation of agricultural crops to increase evapotranspiration (ET) might be an effective way to remove water from the basin. The objectives of this study were to compare ET estimates derived from application of the Mapping ET at High Resolution with Internalized Calibration (METRIC) algorithm for North Dakota conditions (METRICND) under irrigated and rainfed conditions and to assess the potential for irrigation to increase crop ET as a flood mitigation strategy. Weather data, land use maps, and Landsat 5 Thematic Mapper imagery from 2006, 2007, and 2008 were used as inputs to the METRICND model. The ET for irrigated crops (ETIrrigated) was estimated at five test sites from the Devils Lake Basin Water Utilization Test Project (DLBWUTP). The ET for the predominantly rainfed study area (ETRainfed) was estimated using land use maps to identify locations of the same crops as were present on the test sites. The METRICND model was compared to ET values derived from an eddy covariance (EC) system for approximately two months in 2007 at an irrigated alfalfa test site in the DLBWUTP; the mean absolute error between METRICND and the EC system for the comparison period was 0.51 mm d-1. Linear regression of ET (in mm) for the test sites and the larger study area yielded ETIrrigated = 1.23 × ETRainfed + 4.77 with R2 = 0.96, and a t-statistic indicated that the slope was greater than 0 at p = 0.001, indicating the potential for increased ET under irrigation. However, addition of large volumes of irrigation water to the predominantly poorly drained soils in the basin will cause waterlogging and trafficability problems. Installation of subsurface drainage may help alleviate waterlogging, improve crop productivity, and increase ET, but subsurface drainage brings its own complications of disposal of the drained water, salinity of the drainage effluent, and possible sodicity problems on some soils. Keywords: Drainage, Evapotranspiration mapping, Irrigation, METRIC, Landsat 5, Remote sensing, Satellite imagery, SEBAL.
- Published
- 2017
231. Global diversity of desert hypolithic cyanobacteria
- Author
-
Teruya Maki, Kimberley A. Warren-Rhodes, Stephen D. J. Archer, Maggie C. Y. Lau, Stephen B. Pointing, Asuncion de los Rios-Murillo, Donnabella C. Lacap-Bugler, Charles Kai-Wu Lee, Len N. Gillman, Christopher P. McKay, Kevin K. Lee, David Hopkins, John K. Perrott, and Sebastian Leuzinger
- Subjects
0301 basic medicine ,Microbiology (medical) ,endocrine system ,lcsh:QR1-502 ,Growing season ,dryland ,Cyanobacteria ,Microbiology ,cyanobacteria ,complex mixtures ,lcsh:Microbiology ,Dryland ,03 medical and health sciences ,Botany ,Chroococcidiopsis ,Desert ,biogeography ,desert ,Original Research ,hypolith ,biology ,Ecology ,fungi ,Hypolith ,biology.organism_classification ,Tundra ,Burkholderiales ,030104 developmental biology ,Arctic ,Biogeography ,Proteobacteria ,geographic locations ,Acidobacteria - Abstract
Global patterns in diversity were estimated for cyanobacteria-dominated hypolithic communities that colonize ventral surfaces of quartz stones and are common in desert environments. A total of 64 hypolithic communities were recovered from deserts on every continent plus a tropical moisture sufficient location. Community diversity was estimated using a combined t-RFLP fingerprinting and high throughput sequencing approach. The t-RFLP analysis revealed desert communities were different from the single non-desert location. A striking pattern also emerged where Antarctic desert communities were clearly distinct from all other deserts. Some overlap in community similarity occurred for hot, cold and tundra deserts. A further observation was that the producer-consumer ratio displayed a significant negative correlation with growing season, such that shorter growing seasons supported communities with greater abundance of producers, and this pattern was independent of macroclimate. High-throughput sequencing of 16S rRNA and nifH genes from four representative samples validated the t-RFLP study and revealed patterns of taxonomic and putative diazotrophic diversity for desert communities from the Taklimakan Desert, Tibetan Plateau, Canadian Arctic and Antarctic. All communities were dominated by cyanobacteria and among these 21 taxa were potentially endemic to any given desert location. Some others occurred in all but the most extreme hot and polar deserts suggesting they were relatively less well adapted to environmental stress. The t-RFLP and sequencing data revealed the two most abundant cyanobacterial taxa were Phormidium in Antarctic and Tibetan deserts and Chroococcidiopsis in hot and cold deserts. The Arctic tundra displayed a more heterogenous cyanobacterial assemblage and this was attributed to the maritime-influenced sampling location. The most abundant heterotrophic taxa were ubiquitous among samples and belonged to the Acidobacteria, Actinobacteria, Bacteroidetes, and Proteobacteria. Sequencing using nitrogenase gene-specific primers revealed all putative diazotrophs were Proteobacteria of the orders Burkholderiales, Rhizobiales, and Rhodospirillales. We envisage cyanobacterial carbon input to the system is accompanied by nitrogen fixation largely from non-cyanobacterial taxa. Overall the results indicate desert hypoliths worldwide are dominated by cyanobacteria and that growing season is a useful predictor of their abundance. Differences in cyanobacterial taxa encountered may reflect their adaptation to different moisture availability regimes in polar and non-polar deserts.
- Published
- 2017
232. DEPOSITIONAL FACIES INFLUENCE ON SHALLOW BURIAL DOLOMITIZATION, AND TRIASSIC DEDOLOMITIZATION, MIDDLE CAMBRIAN LEDGER FORMATION, YORK, PENNSYLVANIA
- Author
-
David Hopkins, Monica M. Arienzo, Carol B. De Wet, and Philip Dinterman
- Subjects
Depositional facies ,Ledger ,Geochemistry ,Dolomitization ,Geology - Published
- 2017
- Full Text
- View/download PDF
233. Type 1 diabetes structured education: what are the core self-management behaviours?
- Author
-
Debbie Cooke, S. Lucas, Julia Lawton, Marie Clark, Jackie Elliott, Simon Heller, L. Grant, David Hopkins, I. MacLellan, and Mark Davies
- Subjects
Endocrinology, Diabetes and Metabolism ,media_common.quotation_subject ,Health Behavior ,Guidelines as Topic ,State Medicine ,Diabetes Complications ,Carbohydrate counting ,Endocrinology ,Patient Education as Topic ,Surveys and Questionnaires ,Diet, Diabetic ,Health care ,Internal Medicine ,Humans ,Hypoglycemic Agents ,Insulin ,Medicine ,Group work ,Empowerment ,Goal setting ,Curriculum ,media_common ,Medical education ,Self-management ,business.industry ,Blood Glucose Self-Monitoring ,International Agencies ,Combined Modality Therapy ,Hypoglycemia ,United Kingdom ,Self Care ,Diabetes Mellitus, Type 1 ,Hyperglycemia ,Workforce ,Patient Compliance ,business - Abstract
Aims Study aims were to (1) describe and compare the way diabetes structured education courses have evolved in the UK, (2) identify and agree components of course curricula perceived as core across courses and (3) identify and classify self-care behaviours in order to develop a questionnaire assessment tool. Methods Structured education courses were selected through the Type 1 diabetes education network. Curricula from five courses were examined and nine educators from those courses were interviewed. Transcripts were analysed using framework analysis. Fourteen key stakeholders attended a consensus meeting, to identify and classify Type 1 diabetes self-care behaviours. Results Eighty-three courses were identified. Components of course curricula perceived as core by all diabetes educators were: carbohydrate counting and insulin dose adjustment, hypoglycaemia management, group work, goal setting and empowerment, confidence and control. The broad areas of self-management behaviour identified at the consensus meeting were carbohydrate counting and awareness, insulin dose adjustment, self-monitoring of blood glucose, managing hypoglycaemia, managing equipment and injection sites; and accessing health care. Specific self-care behaviours within each area were identified. Conclusions Planned future work will develop an updated questionnaire tool to access self-care behaviours. This will enable assessment of the effectiveness of existing structured education programmes at producing desired changes in behaviour. It will also help people with diabetes and their healthcare team identify areas where additional support is needed to initiate or maintain changes in behaviour. Provision of such support may improve glycaemia and reduce diabetes-related complications and severe hypoglycaemia.
- Published
- 2013
- Full Text
- View/download PDF
234. Slide rules, nomograms and additive functions
- Author
-
David Hopkins
- Subjects
Slide rule ,Variables ,Scale (ratio) ,Computer science ,General Mathematics ,Carry (arithmetic) ,media_common.quotation_subject ,Value (computer science) ,Division (mathematics) ,law.invention ,law ,Line (geometry) ,Multiplication ,Arithmetic ,media_common - Abstract
Older readers will remember using a slide rule to carry out multiplication and division in the days before calculators. There was also a graphical tool called a nomogram, which was used for evaluating certain functions. Although such devices have little practical use nowadays, I was interested in investigating which classes of functions with two independent variables could be calculated using this type of device.Figure 1 shows how a slide rule was used to multiply 3 by 4 (or equivalently to divide 12 by 4). To do this, you align the 1 on the upper scale with the 3 on the lower scale and then read off the value below the 4 on the upper scale to get 12 (or, for division, you line up the 4 above the 12 and read off the answer 3 on the lower scale).
- Published
- 2013
- Full Text
- View/download PDF
235. Biochar in bioenergy cropping systems: impacts on soil faunal communities and linked ecosystem processes
- Author
-
Adam J. Vanbergen, Nick Ostle, David Hopkins, Richard D. Bardgett, and Sarah A. McCormack
- Subjects
Renewable Energy, Sustainability and the Environment ,Agroforestry ,Soil biodiversity ,Soil biology ,Soil organic matter ,Forestry ,Soil carbon ,Soil quality ,Biochar ,Soil ecology ,Environmental science ,Soil fertility ,Waste Management and Disposal ,Agronomy and Crop Science - Abstract
Biochar amendment of soil and bioenergy cropping are two eco-engineering strategies at the forefront of attempts to offset anthropogenic carbon dioxide (CO2) emissions. Both utilize the ability of plants to assimilate atmospheric CO2, and are thus intrinsically linked with soil processes. Research to date has shown that biochar and bioenergy cropping change both aboveground and belowground carbon cycling and soil fertility. Little is known, however, about the form and function of soil food webs in these altered ecosystems, or of the consequences of biodiversity changes at higher trophic levels for soil carbon sequestration. Hitherto studies on this topic have been chiefly observational, and often report contrasting results, thus adding little mechanistic understanding of biochar and bioenergy cropping impacts on soil organisms and linked ecosystem processes. This means it is difficult to predict, or control for, changes in biotic carbon cycling arising from biochar and bioenergy cropping. In this study we explore the potential mechanisms by which soil communities might be affected by biochar, particularly in soils which support bioenergy cropping. We outline the abiotic (soil quality-mediated) and biotic (plant- and microbe-mediated) shifts in the soil environment, and implications for the abundance, diversity, and composition of soil faunal communities. We offer recommendations for promoting biologically diverse, fertile soil via biochar use in bioenergy crop systems, accompanied by specific future research priorities.
- Published
- 2013
- Full Text
- View/download PDF
236. First Defense : Anxiety and Instinct for Self-Protection
- Author
-
David Hopkins, PhD and David Hopkins, PhD
- Subjects
- Self-protective behavior, Self-preservation, Self-defense--Psychological aspects, Instinct, Intuition, Anxiety, Crime prevention--Psychological aspects, Fear of crime--Psychological aspects, Violence--Psychological aspects, Victims of crimes--Psychology
- Abstract
Next Generation Indie Book Award FINALIST - 2016USA Best Book Award FINALIST - 2015Anxiety is your built-in self-defense system. Use it. Anxiety happens whether you like it or not. It's your body's way of telling you “something is wrong here.” Learning how to use anxiety as a personal weapon for self-defense is the best way you can achieve awareness and avoidance, which are the first two steps learned in self-defense preparedness training. Everyone is born with an instinctual survival mechanism. In fact, it has kept humankind safe for millennia. Unfortunately, most of us have been conditioned to ignore it. That's dangerous. • Understand why your instincts are the key to making the right decisions. • Recognize how anxiety is the link between decision-making and instinct. • Learn how to be completely in the moment, so you can coordinate anxiety and instinct into a highly effective decision-making process. You will learn how to develop personal safety skills by doing thought exercises, both in your home and in public spaces. These important exercises will help you become more aware of your surroundings and empower you to make the right decision on what or who to avoid. First Defense should be read by most people, including • Parents • Seniors • College students • Martial artists (especially females) • Employees of midsize to large companies • Teachers “This book belongs in the library of any martial artist, law enforcement and military professional, close protection agent, and anyone interested in augmenting their warrior skills.” —Tomer Israel, chief of Israeli Tactical School
- Published
- 2015
237. Taxonomic and functional diversity of soil and hypolithic microbial communities in Miers Valley, McMurdo Dry Valleys, Antarctica
- Author
-
Tancredi Caruso, Jill M.Y. Chiu, Maggie C. Y. Lau, Subramanya Rao, Jizhong Zhou, Asunción de los Ríos, Colleen M. Higgins, Sean Ting-Shyang Wei, David Hopkins, Joy D. Van Nostrand, Stephen K. Archer, Donnabella C. Lacap-Bugler, and Stephen B. Pointing
- Subjects
0301 basic medicine ,Microbiology (medical) ,Geochip ,Environmental Science and Management ,lcsh:QR1-502 ,Biology ,Cyanobacteria ,cyanobacteria ,Microbiology ,lcsh:Microbiology ,Actinobacteria ,soil ,03 medical and health sciences ,Functional diversity ,Nutrient ,permafrost soils ,Original Research ,hypolith ,Ecology ,Hypolith ,respiratory system ,biology.organism_classification ,Substrate (marine biology) ,030104 developmental biology ,Soil water ,Soil Sciences ,GeoChip ,Antarctica ,Adaptation ,Dry Valleys ,human activities ,Polar desert - Abstract
The McMurdo Dry Valleys of Antarctica are an extreme polar desert. Mineral soils support subsurface microbial communities and translucent rocks support development of hypolithic communities on ventral surfaces in soil contact. Despite significant research attention, relatively little is known about taxonomic and functional diversity or their inter-relationships. Here we report a combined diversity and functional interrogation for soil and hypoliths of the Miers Valley in the McMurdo Dry Valleys of Antarctica. The study employed 16S rRNA fingerprinting and high throughput sequencing combined with the GeoChip functional microarray. The soil community was revealed as a highly diverse reservoir of bacterial diversity dominated by actinobacteria. Hypolithic communities were less diverse and dominated by cyanobacteria. Major differences in putative functionality were that soil communities displayed greater diversity in stress tolerance and recalcitrant substrate utilization pathways, whilst hypolithic communities supported greater diversity of nutrient limitation adaptation pathways. A relatively high level of functional redundancy in both soil and hypoliths may indicate adaptation of these communities to fluctuating environmental conditions.
- Published
- 2016
- Full Text
- View/download PDF
238. SVA‚ a tool for analysing shared−variable programms
- Author
-
A.W. Roscoe and David Hopkins
- Published
- 2016
239. Temporal dynamics of hot desert microbial communities reveal structural and functional responses to water input
- Author
-
Don A. Cowan, Thulani P. Makhalanyane, Mary Seely, Marla Trindade, Alacia Armstrong, Jean-Baptiste Ramond, David Hopkins, Janet K. Jansson, Thomas J. Aspray, Angel Valverde, National Research Foundation (South Africa), Research Council of Norway, University of Western Cape, Valverde Portal, Ángel, and Valverde Portal, Ángel [0000-0003-0439-9605]
- Subjects
0301 basic medicine ,Multidisciplinary ,Community ,Ecology ,Soil biology ,Arid ,complex mixtures ,Article ,03 medical and health sciences ,030104 developmental biology ,Microbial population biology ,Productivity (ecology) ,Environmental science ,Spatial variability ,Ecosystem ,Species richness - Abstract
8 páginas, 4 figuras. -- The first publication is available at https://www.nature.com, The temporal dynamics of desert soil microbial communities are poorly understood. Given the implications for ecosystem functioning under a global change scenario, a better understanding of desert microbial community stability is crucial. Here, we sampled soils in the central Namib Desert on sixteen different occasions over a one-year period. Using Illumina-based amplicon sequencing of the 16S rRNA gene, we found that α-diversity (richness) was more variable at a given sampling date (spatial variability) than over the course of one year (temporal variability). Community composition remained essentially unchanged across the first 10 months, indicating that spatial sampling might be more important than temporal sampling when assessing β-diversity patterns in desert soils. However, a major shift in microbial community composition was found following a single precipitation event. This shift in composition was associated with a rapid increase in CO2 respiration and productivity, supporting the view that desert soil microbial communities respond rapidly to re-wetting and that this response may be the result of both taxon-specific selection and changes in the availability or accessibility of organic substrates. Recovery to quasi pre-disturbance community composition was achieved within one month after rainfall., We gratefully acknowledge financial support from the National Research Foundation of South Africa (grant no.81779 and TTK2008052000003), the Research Council of Norway (grant No. 180352) and the University of the Western Cape. Partial support was also provided under the Laboratory Directed Research and Development Program at PNNL, a multiprogram national laboratory operated by Battelle for the U.S. Department of Energy under contract DE-AC05-76RL01830.
- Published
- 2016
240. The Role of Microbial Community Composition in Controlling Soil Respiration Responses to Temperature
- Author
-
Fiona Fraser, Kristiina Karhu, Amit N. Khachane, Philip A. Wookey, James I. Prosser, Jennifer A.J. Dungait, David Hopkins, Brajesh K. Singh, Thomas E. Freitag, Iain P. Hartley, and Marc D. Auffret
- Subjects
0301 basic medicine ,Time Factors ,Q10 ,lcsh:Medicine ,Forests ,Biochemistry ,Soil respiration ,Soil ,Biomass ,lcsh:Science ,2. Zero hunger ,Biomass (ecology) ,Multidisciplinary ,Ecology ,Chemistry ,Microbiota ,Temperature ,Soil chemistry ,04 agricultural and veterinary sciences ,Soil Ecology ,Terrestrial Environments ,Enzymes ,Community Ecology ,Fumigation ,Research Article ,Ecological Metrics ,Cell Respiration ,Biomass (Ecology) ,Soil Science ,Ecosystems ,03 medical and health sciences ,Q10 Temperature Coefficient ,Respiration ,Soil ecology ,Community Structure ,Soil organic matter ,lcsh:R ,Ecology and Environmental Sciences ,Organisms ,Fungi ,Biology and Life Sciences ,Proteins ,Sequence Analysis, DNA ,15. Life on land ,030104 developmental biology ,Microbial population biology ,Soil Respiration ,13. Climate action ,040103 agronomy & agriculture ,Linear Models ,Enzymology ,0401 agriculture, forestry, and fisheries ,lcsh:Q - Abstract
Rising global temperatures may increase the rates of soil organic matter decomposition by heterotrophic microorganisms, potentially accelerating climate change further by releasing additional carbon dioxide (CO2) to the atmosphere. However, the possibility that microbial community responses to prolonged warming may modify the temperature sensitivity of soil respiration creates large uncertainty in the strength of this positive feedback. Both compensatory responses (decreasing temperature sensitivity of soil respiration in the long-term) and enhancing responses (increasing temperature sensitivity) have been reported, but the mechanisms underlying these responses are poorly understood. In this study, microbial biomass, community structure and the activities of dehydrogenase and β-glucosidase enzymes were determined for 18 soils that had previously demonstrated either no response or varying magnitude of enhancing or compensatory responses of temperature sensitivity of heterotrophic microbial respiration to prolonged cooling. The soil cooling approach, in contrast to warming experiments, discriminates between microbial community responses and the consequences of substrate depletion, by minimising changes in substrate availability. The initial microbial community composition, determined by molecular analysis of soils showing contrasting respiration responses to cooling, provided evidence that the magnitude of enhancing responses was partly related to microbial community composition. There was also evidence that higher relative abundance of saprophytic Basidiomycota may explain the compensatory response observed in one soil, but neither microbial biomass nor enzymatic capacity were significantly affected by cooling. Our findings emphasise the key importance of soil microbial community responses for feedbacks to global change, but also highlight important areas where our understanding remains limited.
- Published
- 2016
241. Editorial
- Author
-
David Hopkins
- Subjects
Food Science - Published
- 2018
- Full Text
- View/download PDF
242. The time cost of access to food – Distance to the grocery store as measured in minutes
- Author
-
Emerit David Hopkins, David L. Hopkins, and Karen S. Hamrick
- Subjects
050210 logistics & transportation ,Grocery store ,Sociology and Political Science ,05 social sciences ,Economics, Econometrics and Finance (miscellaneous) ,Advertising ,Time cost ,Limited access ,Travel time ,03 medical and health sciences ,Travel behavior ,Time-use survey ,0302 clinical medicine ,0502 economics and business ,Food desert ,030212 general & internal medicine ,Business ,Marketing ,Grocery shopping - Abstract
Time use diaries are rich in information, including where and when respondents travel from place to place. Travel estimates, as well as variety of contextual information on travel, can be generated from time use data. However, using the data for travel analysis is difficult and involves detailed understanding of how the data are coded. Presented here is a methodology for estimating travel time using the time diaries from the 2003-07 Amer-ican Time Use Survey. As an illustration of the methodology, the authors estimate travel time to grocery shopping. These estimates are of interest as a policy concern in the United States is whether or not somepoor areas of the country have access to supermarkets that offer the variety of foods needed for a healthy diet, and in particular, fresh fruits and vegetables. Neighborhoods that have limited access to supermarkets are referred as “food deserts.” The authors found that individuals living in low-income areas with limited supermarket access spend significantly more time (an average of 19.5 minutes) traveling to grocery shopping than the national average (15minutes), and in addition, they grocery shop less frequently, and they are more likely to be accompanied by children during travel to grocery shopping.
- Published
- 2012
- Full Text
- View/download PDF
243. How many winners will there be?
- Author
-
David Hopkins
- Subjects
General Mathematics - Abstract
Some years ago I was invited to take part in a fund-raising competition, [1]. The rules had an interesting feature that led me to analyse the situation mathematically. This resulted in some interesting formulae and one inequality, which I will describe here.The competition offered a single prize and the entry form looked similar to the partially-completed example illustrated below.The form listed 40 categories similar to the ones shown. Participants were required to write down an ‘answer’ for each category, e.g. for ‘an animal’, you might choose DOG. No other indications were given, so each answer was a completely free choice.
- Published
- 2012
- Full Text
- View/download PDF
244. Stand-Alone Mass Media Campaigns to Increase Physical Activity
- Author
-
Leigh Ramsey Buchanan, Tina Lankford, David Hopkins, Jesus Soares, David R. Brown, C. Tracy Orleans, Jacqueline M. Epping, and Jana Wallace
- Subjects
Gerontology ,Population level ,Epidemiology ,business.industry ,Public Health, Environmental and Occupational Health ,Physical activity ,Context (language use) ,Percentage point ,Weight loss ,Interquartile range ,medicine ,medicine.symptom ,business ,Evidence synthesis ,Mass media - Abstract
Context: The goal of the systematic review described in this summary was to determine the effectiveness of stand-alone mass media campaigns to increase physical activity at the population level. This systematic review is an update of a Community Guide systematic review and Community Preventive Services Task Force recommendation completed in 2001. Evidence acquisition: Updated searches for literature published from 1980 to 2008 were con- ducted in 11 databases. Of 267 articles resulting from the literature search, 16 were selected for full abstraction, including the three studies from the original 2001 review. Standard Community Guide methods were used to conduct the systematic evidence review. Evidence synthesis: Physical activity outcomes were assessed using a variety of self-report mea- sures with duration intervals ranging from 6 weeks to 4 years. Ten studies using comparable outcome measures documented a median absolute increase of 3.4 percentage points (interquartile interval: 2.4 to 4.2 percentage points), and a median relative increase of 6.7% (interquartile interval: 3.0% to 14.1%), in self-reported physical activity levels. The remaining six studies used alternative outcome measures: three evaluated changes in self-reported time spent in physical activity (median relative change, 4.4%; range of values, 3.1%-18.2%); two studies used a single outcome measure and found that participants reported being more active after the campaign than before it; and one study found that a mass media weight-loss program led to a self-reported increase in physical activity. Conclusions: The findings of this updated systematic review show that intervention effects, based wholly on self-reported measures, were modest and inconsistent. These findings did not lead the Task Force to change its earlier conclusion of insufficient evidence to determine the effectiveness of stand-alone mass media campaigns to increase physical activity. This paper also discusses areas needing future research to strengthen the evidence base. Finally, studies published between 2009 and 2011, after the Task Force finding was reached, and briefly summarized here, are shown to support that finding.
- Published
- 2012
- Full Text
- View/download PDF
245. Microbial responses to carbon and nitrogen supplementation in an Antarctic dry valley soil
- Author
-
Edward G. Gregorich, Philip M. Novis, Paul G. Dennis, David Hopkins, Bo Elberling, Ashley D. Sparrow, and L.G. Greenfield
- Subjects
Total organic carbon ,Biogeochemical cycle ,Chemistry ,Ecology ,Soil organic matter ,chemistry.chemical_element ,Geology ,Soil carbon ,Oceanography ,Nitrogen ,Microbial population biology ,Environmental chemistry ,Soil water ,Dominance (ecology) ,Ecology, Evolution, Behavior and Systematics - Abstract
The soils of the McMurdo Dry Valleys are exposed to extremely dry and cold conditions. Nevertheless, they contain active biological communities that contribute to the biogeochemical processes. We have used ester-linked fatty acid (ELFA) analysis to investigate the effects of additions of carbon and nitrogen in glucose and ammonium chloride, respectively, on the soil microbial community in a field experiment lasting three years in the Garwood Valley. In the control treatment, the total ELFA concentration was small by comparison with temperate soils, but very large when expressed relative to the soil organic carbon concentration, indicating efficient conversion of soil organic carbon into microbial biomass and rapid turnover of soil organic carbon. The ELFA concentrations increased significantly in response to carbon additions, indicating that carbon supply was the main constraint to microbial activity. The large ELFA concentrations relative to soil organic carbon and the increases in ELFA response to organic carbon addition are both interpreted as evidence for the soil microbial community containing organisms with efficient scavenging mechanisms for carbon. The diversity of the ELFA profiles declined in response to organic carbon addition, suggesting the responses were driven by a portion of the community increasing in dominance whilst others declined.
- Published
- 2012
- Full Text
- View/download PDF
246. Evaluation of 1:5 soil to water extract electrical conductivity methods
- Author
-
Lyle Prunty, Yangbo He, David Hopkins, Thomas M. DeSutter, Douglas A. Wysocki, and Xinhua Jia
- Subjects
Salinity ,Hydrology ,Soil salinity ,North central ,Chemistry ,Electrical resistivity and conductivity ,Soil water ,Soil Science ,Soil science - Abstract
Conducting a 1:5 soil:water extract to measure electrical conductivity (EC) is an approach to assess salinity and has been the preferred method in Australia, but not commonly used in the United States where the 1:1 soil to water ratio is preferred. The objectives of this research were to 1) compare methods of agitation for determining EC 1:5 and 2) to determine optimal times for equilibration for each method across a range of salinity levels determined from EC values achieved from saturated paste extracts (EC e ). Soils evaluated for this study were from north central North Dakota (USA) and had EC e values ranging from 0.96 to 21.2 dS m − 1 . For each method, nine agitation times were used, up to 48 h. The three agitation methods were shaking plus centrifuging, shaking, and stirring. Agitation methods resulted in significantly different EC 1:5 values for 13 out of 20 soils across the three agitation methods, and shaking plus centrifuging was significantly different ( p = 0.05) from stirring for all soils. In addition, 75% of the shaking plus centrifuging soils were significantly different from shaking. Based on these results, methods were analyzed separately for optimal equilibration times. The agitation times required for the three methods to reach 95 and 98% of equilibration were a function of the level of soil salinity. For soils with EC e values below 4 dS m − 1 , over 24 h was needed to obtain both 95 and 98% of equilibration for the three methods. However, less than 3 and 8 h were needed to reach 95 and 98% equilibration, respectively, across methods for soils having EC e values greater than 4 dS m − 1 . These results indicate that investigating the effect of agitation methods and times is important to help reduce variations across EC 1:5 measurements.
- Published
- 2012
- Full Text
- View/download PDF
247. Soil fungal community composition does not alter along a latitudinal gradient through the maritime and sub-Antarctic
- Author
-
David Hopkins, V.J. Ord, Paul G. Dennis, Kevin K. Newsham, Tim J. Daniell, Steven Rushton, Vito A Lauducina, Anthony G. O'Donnell, Dennis, PG, Rushton, SP, Newsham, KK, Laudicina, VA, Ord, VJ, Daniell, TJ, O'Donnell, AG, and Hopkins, DW
- Subjects
Total organic carbon ,Antarctica C:N ratio Extreme environments Latitudinal gradient pH Soil fungal community composition ,0303 health sciences ,Ecology ,030306 microbiology ,Range (biology) ,Ecological Modeling ,Settore AGR/13 - Chimica Agraria ,Plant Science ,Mars Exploration Program ,15. Life on land ,Biology ,Latitude ,03 medical and health sciences ,Oceanography ,Community composition ,Soil pH ,Soil water ,Extreme environment ,14. Life underwater ,Ecology, Evolution, Behavior and Systematics ,030304 developmental biology - Abstract
We investigated the relationships between fungal community composition, latitude and a range of physicochemical parameters in 58 soils sampled from a 2370 km latitudinal gradient between South Georgia (54 S, 38 W) in the sub-Antarctic and Mars Oasis (72 S, 68 W) on Alexander Island in the southern maritime Antarctic. Our study, which is based on approximately ten times the number of samples used in previous similar studies, indicates that latitude and its associated environmental parameters are not related to fungal community composition. Significant changes in the composition of soil fungal communities were observed in relation to gradients of the ratio of total organic carbon to nitrogen, and, to a lesser extent, soil pH.
- Published
- 2012
- Full Text
- View/download PDF
248. How do enzymes catalysing soil nitrogen transformations respond to changing temperatures?
- Author
-
Philip A. Wookey, Iain P. Hartley, Paul D. Hallett, David Hopkins, and Fiona Fraser
- Subjects
Protease ,Urease ,biology ,Chemistry ,medicine.medical_treatment ,Soil Science ,Mineralization (soil science) ,Microbiology ,Amidase ,Carbon cycle ,Biochemistry ,Environmental chemistry ,Soil water ,Amidase activity ,medicine ,biology.protein ,Agronomy and Crop Science ,Nitrogen cycle - Abstract
Biological processes in soils are regulated in part by soil temperature, and there is currently considerable interest in obtaining robust information on the temperature sensitivity of carbon cycling process. However, very little comparable information exists on the temperature regulation of specific nitrogen cycling processes. This paper addresses this problem by measuring the temperature sensitivity of nitrogen cycling enzymes in soil. A grassland soil was incubated over a range of temperatures (−2 to 21 °C) reflecting 99 % of the soil temperature range during the previous 50 years at the site. After 7 and 14 days of incubation, potential activities of protease, amidase and urease were determined. Activities of protease and urease were positively related to temperature (activation energy; E a = 49.7 and 73.4 kJ mol−1, respectively, and Q 10 = 2.97 and 2.78, respectively). By contrast, amidase activity was relatively insensitive to temperature, but the activity was significantly increased after the addition of glucose. This indicated that there was a stoichiometric imbalance with amidase activity only being triggered when there was a supply of exogenous carbon. Thus, carbon supply was a greater constraint to amidase activity than temperature was in this particular soil.
- Published
- 2012
- Full Text
- View/download PDF
249. Decomposition of tobacco roots with modified phenylpropanoid content by fungi with contrasting lignocellulose degradation strategies
- Author
-
Claire Halpin, E. L. Tilston, and David Hopkins
- Subjects
Chaetomium globosum ,Phenylpropanoid ,Soil Science ,Biology ,biology.organism_classification ,complex mixtures ,Microbiology ,Decomposition ,Decomposer ,chemistry.chemical_compound ,chemistry ,Microbial population biology ,Botany ,Lignin ,Phanerochaete ,Agronomy and Crop Science ,Chrysosporium - Abstract
The decomposition of tobacco roots with genetic modifications to lignin biosynthesis by the ligninolytic fungus Phanerochaete chrysosporium, by the cellulolytic fungus Chaetomium globosum, and by microbial communities in soil were examined to determine whether the rates of decomposition of the modified and unmodified roots decomposed at different rates, whether the order of colonization by P. chrysosporium and C. globosum facilitated decomposition, and whether the microbial community in soil was conditioned by exposure to roots subsequently so that the subsequent decomposition of the roots was increased. Both P. chrysosporium and C. globosum decomposed the modified roots more rapidly, at least initially, than the unmodified roots. Colonization by P. chrysosporium facilitated the subsequent decomposition by C. globosum, presumably because by degrading lignin, P. chrysosporium increased the susceptibility of the polysaccharide component of root material to attack by C. globosum. Selection of the soil microbial community by exposure to the modified residues accelerated subsequent decomposition of the root modified. Although demonstrating effects of the lignin modification on decomposition, they are relatively subtle and in most cases short-lived (less than 40 days) ones to which the microbial community is able to adapt, and therefore, we conclude that there are unlikely to be any persistent effects of the modified lignin on the soil decomposer community.
- Published
- 2012
- Full Text
- View/download PDF
250. Improved Biomedical and Psychological Outcomes 1 Year After Structured Education in Flexible Insulin Therapy for People With Type 1 Diabetes
- Author
-
Simon Heller, Peter Mansell, G. Thompson, IG Lawrence, Stephanie A. Amiel, Michael J. Campbell, and David Hopkins
- Subjects
Research design ,Adult ,Male ,medicine.medical_specialty ,Endocrinology, Diabetes and Metabolism ,Hypoglycemia ,Anxiety ,Hospital Anxiety and Depression Scale ,law.invention ,Randomized controlled trial ,Patient Education as Topic ,law ,Surveys and Questionnaires ,Internal Medicine ,medicine ,Humans ,Insulin ,Depression (differential diagnoses) ,Original Research ,Advanced and Specialized Nursing ,Glycated Hemoglobin ,Type 1 diabetes ,business.industry ,Depression ,Clinical Care/Education/Nutrition/Psychosocial Research ,Middle Aged ,medicine.disease ,Diabetes Mellitus, Type 1 ,Treatment Outcome ,Physical therapy ,DAFNE ,Female ,medicine.symptom ,business - Abstract
OBJECTIVE DAFNE (Dose Adjustment For Normal Eating), a structured education program in flexible insulin therapy, has been widely adopted in the U.K. after validation in a randomized trial. To determine benefits in routine practice, we collected biomedical and psychological data from all participants attending during a 12-month period. RESEARCH DESIGN AND METHODS HbA1c, weight, self-reported hypoglycemia awareness, severe hypoglycemia frequency, PAID (Problem Areas In Diabetes), HADS (Hospital Anxiety and Depression Scale), and EuroQol Group 5-Dimension Self-Report Questionnaire scores were recorded prior to DAFNE and after 1 year. RESULTS Complete baseline and follow-up HbA1c data were available for 639 (54.9%) of 1,163 attendees. HbA1c fell from 8.51 ± 1.41 (mean ± SD) to 8.24 ± 1.29% (difference 0.27 [95% CI 0.16–0.38]; P < 0.001), with a greater mean fall of 0.44% from baseline HbA1c >8.5%. Severe hypoglycemia rate fell from 1.7 ± 8.5 to 0.6 ± 3.7 episodes per person per year (1.1 [0.7–1.4]) and hypoglycemia recognition improved in 43% of those reporting unawareness. Baseline psychological distress was evident, with a PAID score of 25.2 and HADS scores of 5.3 (anxiety) and 4.8 (depression), falling to 16.7 (8.5 [6.6–10.4]), 4.6 (0.7 [0.4–1.0]), and 4.2 (0.6 [0.3–0.8]), respectively (all P < 0.001 at 1 year). Clinically relevant anxiety and depression (HADS ≥8) fell from 24.4 to 18.0% and 20.9 to 15.5%, respectively. CONCLUSIONS A structured education program delivered in routine clinical practice not only improves HbA1c while reducing severe hypoglycemia rate and restoring hypoglycemia awareness but also reduces psychological distress and improves perceived well-being.
- Published
- 2012
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.