ORCID Profile
0000-0002-3465-8383
Current Organisation
The University of Edinburgh
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Publisher: Health Affairs (Project Hope)
Date: 03-2011
Publisher: International Global Health Society
Date: 15-02-2019
Publisher: Elsevier BV
Date: 02-2006
DOI: 10.1016/J.PHYTOCHEM.2005.11.027
Abstract: Adaptation to aridity is considered a major factor in the evolution of the genus Eucalyptus. For the first time, targeted metabolite profiling has uncovered a quantitative yet discrete phytochemical link with eucalypt taxonomy. The distribution of cyclitols among Eucalyptus species, and a range of other Australian tree genera, support their proposed functions in plant tissues and provide putative links with the acclimation of trees to arid environments.
Publisher: Informa UK Limited
Date: 07-2005
Publisher: International Global Health Society
Date: 02-04-2019
Publisher: Informa UK Limited
Date: 07-2005
DOI: 10.1080/09540120500120278
Abstract: The findings of the six independent studies on institutional forms of HIV discrimination in the Asia Pacific presented in this Special Issue of AIDS Care are integrated. At first glance, the general pattern of the results across the study sites suggests that discrimination is most pertinent in the domain of 'practice' rather than in the domains of law or institutional policy. On closer analysis, however, utilising the qualitative data, this conclusion does not take sufficient account of the cultural context within which the interpersonal interaction (practice) between the health carers and people living with HIV/AIDS occurs. Limitations on the use of anti-discrimination legislations and protective written policies for reducing discrimination in these contexts are discussed. The need for alternative approaches to thinking about discrimination intervention is raised and this is done through a consideration of the strategy of universal precautions.
Publisher: Elsevier BV
Date: 09-2007
Publisher: International Global Health Society
Date: 18-05-2016
Publisher: Springer Science and Business Media LLC
Date: 05-10-2007
Publisher: International Global Health Society
Date: 21-05-2016
Publisher: Health Affairs (Project Hope)
Date: 10-2015
DOI: 10.1377/HLTHAFF.2015.0074
Abstract: In 2009 China announced plans to reform provider payment methods at public hospitals by moving from fee-for-service (FFS) to prospective and aggregated payment methods that included the use of diagnosis-related groups (DRGs) to control health expenditures. In October 2011 health policy makers selected six Beijing hospitals to pioneer the first DRG payment system in China. We used hospital discharge data from the six pilot hospitals and eight other hospitals, which continued to use FFS and served as controls, from the period 2010-12 to evaluate the pilot's impact on cost containment through a difference-in-differences methods design. Our study found that DRG payment led to reductions of 6.2 percent and 10.5 percent, respectively, in health expenditures and out-of-pocket payments by patients per hospital admission. We did not find evidence of any increase in hospital readmission rates or cost shifting from cases eligible for DRG payment to ineligible cases. However, hospitals continued to use FFS payments for patients who were older and had more complications than other patients, which reduced the effectiveness of payment reform. Continuous evidence-based monitoring and evaluation linked with adequate management systems are necessary to enable China and other low- and middle-income countries to broadly implement DRGs and refine payment systems.
Publisher: International Global Health Society
Date: 03-09-2015
Publisher: Springer Science and Business Media LLC
Date: 2008
Publisher: International Global Health Society
Date: 12-2019
Publisher: Elsevier BV
Date: 12-2019
DOI: 10.1016/J.SOCSCIMED.2019.112590
Abstract: In 2012, China's first diagnosis-related group (DRG) payment system was piloted in Beijing. This study explored whether this payment pilot improved quality and reduced costs of acute myocardial infarction (AMI) care in hospitals implementing DRG payment as compared to control hospitals. A difference-in-difference study design was used with regression and considered several quality indicators including aspirin at arrival, aspirin at discharge, β-blocker at arrival, β-blocker at discharge, statin at discharge, in-hospital mortality, and 30-day readmission rates. DRG payment mechanisms without specific mechanisms to promote care quality did not improve quality of AMI care. Future studies should study the impact of cost control mechanisms together with quality improvement efforts to assess how quality of care may be improved within the Chinese healthcare system. These lessons would be helpful to share with lower-middle-income countries undergoing rapid development that are transitioning to a significantly higher burden of non-communicable diseases.
Publisher: Wiley
Date: 04-07-2006
Publisher: Springer Science and Business Media LLC
Date: 16-03-2008
DOI: 10.1007/S10461-007-9222-Y
Abstract: This paper analyzes the interrelationships between the stigma of HIV/AIDS stigma and the co-stigmas of commercial sex (CS) and injecting drug use (IDU). Students of a Bangkok nursing college (N=144) were presented with vignettes describing a person varying in the disease diagnoses (AIDS, leukemia, no disease) and co-characteristics (IDU, CS, blood transfusion, no co-characteristic). For each vignette, participants completed a social distance measure assessing their attitudes towards the hypothetical person portrayed. Multivariate analyses showed strong interactions between the stigmas of AIDS and IDU but not between AIDS and CS. Although AIDS was shown to be stigmatizing in and of itself, it was significantly less stigmatizing than IDU. The findings highlight the need to consider the non-disease-related stigmas associated with HIV as well as the actual stigma of HIV/AIDS in treatment and care settings. Methodological strengths and limitations were evaluated and implications for future research discussed.
Publisher: Wiley
Date: 10-2004
Publisher: Informa UK Limited
Date: 2003
Publisher: Wiley
Date: 16-03-2005
Publisher: Public Library of Science (PLoS)
Date: 10-03-2009
Publisher: Public Library of Science (PLoS)
Date: 27-09-2011
Publisher: EDP Sciences
Date: 2005
Publisher: Elsevier BV
Date: 1999
Abstract: A capillary gas chromatographic (GC) method for the simultaneous determination of organic acids, sugars, and sugar alcohols extracted from plant tissues is described. Plant leaves were extracted in 5% (w/v) perchloric acid and neutralized extracts were purified using C18 cartridges. Organic acids, sugars, and sugar alcohols in purified extracts were converted to their trimethylsilyl (TMS)/TMS-oxime derivatives prior to separation and detection by capillary GC with flame ionization detection (FID). Derivatization procedures were investigated in detail and the compounds of interest were readily converted to their TMS/TMS-oxime derivatives using hexamethyldisiazane reagent in acetonitrile solvent (1:6 v/v) at 100 degreesC for 60 min. The derivatives were sufficiently volatile and stable. The FID response to derivatized compounds was generally linear in the concentration range 30-300 microg ml-1, with detection limits in the order of 3-76 ng. The proposed method was demonstrated for the determination of organic acids, sugars, and sugar alcohols in leaf extracts of two native Australian plants.
Publisher: CSIRO Publishing
Date: 2000
DOI: 10.1071/SR99046
Abstract: The spatial heterogeneity of litter cover and bioavailability of nitrogen within a 9-year-old rehabilitated bauxite mine in south Western Australia was examined. Three replicate plots (6 m by 6 m) were each ided into 100 quadrats. Litter cover, vegetation distribution, and projected foliage cover were mapped, and litter (overstorey leaves, understorey leaves, and other assorted fractions) and soil (depth: 0–5, 5–10, and 10–30 cm) were s led from within each quadrat. Litter distribution reflected projected foliage cover, and accumulated within microtopographic depressions. Distribution of soil nitrate (NO3–) reflected the distribution of litter. The 15N natural abundance (d15N) values of soil (0–5 cm) and the understorey litter fraction were significantly correlated (R2 = 0.529, P 0.05), whereas carbon isotope composition (d13C) of soil (0–5 cm) was significantly correlated with the distribution of the assorted litter fraction (R2 = 0.296, P 0.05). It is concluded that site preparation practices that effect microtopography, such as contour ripping and revegetation along contours, will have a significant impact on nitrogen (N) distribution and bioavailability within rehabilitated mine sites.
Publisher: CSIRO Publishing
Date: 2000
DOI: 10.1071/SR99047
Abstract: Mine site rehabilitation should aim to establish quickly and maintain the processes of nutrient cycling at rates comparable with, or approaching, those of native forests. Current management strategies for rehabilitating bauxite mines and other mine sites in Australia usually include planting fast-growing understorey species at high densities and applying fertiliser. We provide the first detailed study of nitrogen (N) availability and N transformations (mineralisation/immobilisation) in such rehabilitated mine sites. Mean concentrations of NO3– (0–5 cm) in a chronosequence (7, 13, 22, and 27 years old) of rehabilitated mine sites ranged from 0.5 to 1.3 kg/ha, and NH4+ from 4.0 to 9.5 kg/ha. In burnt and unburnt native jarrah (E. marginata Donn ex. Smith) forests adjacent to the mine site, mean NO3– concentrations in surface soil (0–5 cm) were 0.8 kg/ha (burnt) and 1.1 kg/ha (unburnt), and mean NH4+ concentrations were 6.8 kg/ha (burnt) and 7.8 kg/ha (unburnt). Concentration of NH4+ at 0–5 cm was strongly related to soil water content (R2 = 0.69, P 0.05) in rehabilitation sites, but not at 5–10 cm depth. Rates of N mineralisation (0–5 cm) in rehabilitation sites ranged from 34 to 52 kg/ha.year, of the same order as rates in native forest soil. In all rehabilitation and native forest sites, rates of N mineralisation were significantly related to rates of N-uptake at both 0–5 and 5–10 cm depth (R2 0.63, P 0.05). Soil C/N ratios (0–5 cm) in rehabilitation sites ranged from 22.4 to 38.8, and in native forests from 35.6 (burnt) to 40.3 (unburnt). Soil C/N ratios increased with depth in both rehabilitation and native forest sites (ranged from 31.2 to 51.6). Availability of water was the major determinant of nitrogen availability in this strongly Mediterranean climate.
Publisher: Springer Science and Business Media LLC
Date: 28-07-2004
DOI: 10.1007/S00442-004-1655-7
Abstract: The Central Asian Taklamakan desert is characterized by a hyperarid climate with less than 50 mm annual precipitation but a permanent shallow groundwater table. The perched groundwater (2-16 m) could present a reliable and constant source of nitrogen throughout the growing season and help overcome temporal nitrogen limitations that are common in arid environments. We investigated the importance of groundwater and nitrogen fixation in the nitrogen metabolism of desert plants by assessing the possible forms and availability of soil N and atmospheric N and the seasonal variation in concentration as well as isotopic composition of plant N. Water availability was experimentally modified in the desert foreland through simulated flooding to estimate the contribution of surface water and temporally increased soil moisture for nutrient uptake and plant-water relations. The natural vegetation of the Taklamakan desert is dominated by plants with high foliar nitrogen concentrations (2-3% DM) and leaf nitrate reductase activity (NRA) (0.2-1 micromol NO2- g(-1) FW h(-1)). There is little evidence that nitrogen is a limiting resource as all perennial plants exhibited fast rates of growth. The extremely dry soil conditions preclude all but minor contributions of soil N to total plant N so that groundwater is suggested as the dominant source of N with concentrations of 100 microM NO3-. Flood irrigation had little beneficial effect on nitrogen metabolism and growth, further confirming the dependence on groundwater. Nitrogen fixation was determined by the 15N natural abundance method and was a significant component of the N-requirement of the legume Alhagi, the average contribution of biologically fixed nitrogen in Alhagi was 54.8%. But nitrogen fixing plants had little ecological advantage owing to the more or less constant supply of N available from groundwater. From our data we conclude that the perennial species investigated have adapted to the environmental conditions through development of root systems that access groundwater to satisfy demands for both water and nutrients. This is an ecologically favourable strategy since only groundwater is a predictable and stable resource.
Publisher: CSIRO Publishing
Date: 2005
DOI: 10.1071/FP05027
Abstract: Salt and water deficit stress elicited contrasting responses in seedlings of Eucalyptus spathulata (Hook.). Under salt stress, seedlings reduced osmotic potential by accumulating large quantities of inorganic ions in leaf tissues. Sodium concentrations reached 350 mm on a leaf water basis and total cellular osmolality reached ∼2000 mm. Under water deficit stress, maximum sodium concentrations were around 50 mm in leaf water and seedlings reduced osmotic potential through increasing concentrations of a range of constitutive solutes up to a total cellular osmolality of ∼1200 mm. We postulate that measured concentrations of the cyclic polyol, quercitol, of up to 200 mm leaf water, are the likely means of balancing accumulation of inorganic ions. Under the common assumption of localisation of inorganic ions to the vacuole and organic balancing solutes to the cytoplasm, the concentrations of cyclitol, and other carbohydrates were more than sufficient to balance osmotic potential across the tonoplast membrane. Results confirm other recent studies that suggest a range of putative roles for cyclitols in tissues and these are discussed in the larger context of plant responses to salt and water deficit stress.
Publisher: Elsevier BV
Date: 08-2008
Publisher: Oxford University Press (OUP)
Date: 19-09-2007
DOI: 10.1093/AOB/MCM234
Publisher: Informa UK Limited
Date: 05-2005
DOI: 10.1080/09540120412331319769
Abstract: HIV-related stigma is regarded as one of the major barriers in the development of effective prevention and care programs but the stigma associated with HIV stigma is not a singular entity. The stigma of the infection is layered with other stigmas, such as those associated with the routes of transmission (e.g., sex work and injecting drug use) and personal characteristics (e.g., race, religion, ethnicity and gender). In developing programs and policies to overcome HIV-related stigma, cognisance needs to be taken of all the sources of stigma, and how they may interact. A novel method is described for examining the layers of HIV/AIDS-related stigma, and secondary data are adapted to illustrate this. The importance of understanding the layering of stigma for the development of effective interventions is also discussed.
Publisher: Public Library of Science (PLoS)
Date: 31-10-2006
Publisher: Elsevier BV
Date: 07-2007
Publisher: Wiley
Date: 07-2003
Publisher: Elsevier BV
Date: 05-1999
Publisher: Oxford University Press (OUP)
Date: 02-2000
Publisher: Wiley
Date: 07-02-2008
Publisher: CSIRO Publishing
Date: 1999
DOI: 10.1071/EA98133
Abstract: The effect of phosphorus fertiliser on plant growth and the quality of leaf tissues for herbivores were investigated in field and glasshouse experiments. In the field, the relative abundance of ephemeral forb species was strongly affected by the seasonal variation in rainfall. In winter, C3 ephemeral forbs were abundant, whilst in summer, C4 ephemeral grasses dominated. During the dry months, growth of all species was poor. After rain, grasses to which phosphorus had been added increased growth significantly. Nutrient concentrations in ephemeral forbs were significantly greater than those in perennial or ephemeral grasses. Phosphorus concentrations were low in perennial and ephemeral grasses and declined during the dry months. The nitrogen : phosphorus ratio of ephemeral forbs and perennial shrubs suggested a deficiency of phosphorus, whilst that of ephemeral grasses suggested a deficiency of nitrogen. A glasshouse experiment investigated the response to phosphorus of 2 common and abundant ephemeral forbs – Ptilotus macrocephalus which responded to all treatments up to a maximum rate of 200 kg P/ha, and Ptilotus exaltatus which increased in growth up to a maximum rate of 100 kg P/ha. In both species, the concentration of phosphorus increased significantly with phosphorus supply, while that of nitrogen did not vary significantly among phosphorus treatments. Generalisations about growth and nitrogen and phosphorus nutrition of native species based on more mesic plant communities are not readily applied in the arid and chronically phosphorus-poor Pilbara environment. Instead, plant life-cycle and life form play major roles in determining nitrogen or phosphorus limitations and plant responses to added nutrients.
Publisher: International Global Health Society
Date: 12-2012
Publisher: Springer Science and Business Media LLC
Date: 23-04-2005
DOI: 10.1007/S00442-005-0092-6
Abstract: The present study examines relative growth rate (RGR) and its determinants in seedlings of nine Eucalyptus species. Species were selected from mesic (1,800 mm a(-1) rainfall) through to semi-arid habitats (300 mm a(-1)), and thus, notionally vary in "stress" tolerance. Seedlings were grown in a glasshouse during early summer and received between 33 mol and 41 mol PAR m(-2) day(-1) . The mean RGR varied among species-from a minimum of 66 mg g(-1) day(-1) in E. hypochlamydea to a maximum of 106 mg g(-1) day(-1) in E. delegatensis. RGR was positively related to rainfall at the sites of seed collection. Neither specific leaf area (SLA) nor net assimilation rate was related to rainfall or RGR. While the absence of relationships with SLA and net assimilation rate contrasts with other studies and species, we cannot rule out the effects of s le size (n=9 species) and modest ranges in SLA and RGR. The ratio of leaf mass to total mass (LMR) varied from 0.49+/-0.07 g g(-1) in E. socialis to 0.74+/-0.04 g g(-1) in E. delegatensis and was strongly positively related with rainfall (r2=0.77). Interspecific differences in RGR were strongly related to LMR (positive relationship, r2=0.50) and the rate of dry matter production per mol of leaf nitrogen (positive relationship, r2=0.64). Hence, the slow RGR of low-rainfall species was functionally related to a lower growth rate per mol of leaf nitrogen than high-rainfall species. Furthermore, slow RGR of low-rainfall species was related to greater allocation to roots at the expense of leaves. Increasing allocation to roots versus leaves is likely an adaptation to soil and atmospheric water deficits, but one that comes at the expense of a slow RGR.
Publisher: Wiley
Date: 08-11-2007
DOI: 10.1111/J.1469-8137.2007.02229.X
Abstract: Although only a small proportion of plant phosphorus (P) is used for photosynthesis, the relationships between P and photosynthesis can be strong. It was hypothesized, in this study, that variation in the allocation of orthophosphate (Pi) between active (cytoplasmic) and nonactive (vacuolar) pools would underpin differences in rates of photosynthesis in 4-month-old Eucalyptus globulus seedlings grown with a varying P supply. Photosynthetic biochemistry was assessed by the response of net photosynthesis to increasing intercellular [CO2]. Cytoplasmic Pi was sequestered as mannose 6-phosphate. Total P and the proportion of P as Pi were positively related to P supply. The ratios of active : stored Pi (10-24%) varied little over the range of treatments. Active Pi was positively related to P supply, as was photosynthesis (7 micromol CO2 m(-2) s(-1) with 0 mM P vs. 16 micromol CO2 m(-2) s(-1) with 0.32 mM P). Positive relationships between P supply and photosynthesis were explained best by leaf P content, not by active pools of Pi. The distribution of Pi between the vacuole and the cytoplasm had little impact on the photosynthetic phosphorus-use efficiency (PPUE), and reductions in cytoplasmic Pi had little effect on photosynthesis. Hence, PPUE is an unsuitable guide for assessing plant responses to increasingly unavailable P in the environment.
Publisher: Elsevier BV
Date: 03-2010
Publisher: International Global Health Society
Date: 12-2012
Publisher: International Society of Global Health
Date: 24-11-2016
Publisher: Springer Science and Business Media LLC
Date: 09-02-2005
Publisher: Informa UK Limited
Date: 06-2009
Publisher: International Global Health Society
Date: 12-2012
Publisher: Informa UK Limited
Date: 07-2005
DOI: 10.1080/09540120500120211
Abstract: The systematic measurement of HIV/AIDS-related discrimination is imperative within the current rhetoric that holds discrimination as one of the two 'biggest' barriers to HIV/AIDS pandemic intervention. This paper provides a methodological critique of the UNAIDS (2000b) Protocol for the Identification of Discrimination against People Living with HIV (the Protocol). Specifically, the paper focuses on the Protocol's capacity to accurately identify and measure institutional levels of HIV-related discrimination that allows data that are reliable and comparable across time and contexts. Conceptual issues including the Protocol's objective as an indicator versus a direct measure of discrimination and the role of the Protocol as a tool of research versus a tool of advocacy are explored. Design issues such as the operationalization of discrimination, appropriateness of indicator content, s ling and data collection strategies and issues of scoring are also evaluated. It is hoped that the matters outlined will provide readers with ways of critically reflecting and evaluating the findings of the research papers presented in this Special Issue, as well as pointing to ways of improving research design.
Publisher: International Global Health Society
Date: 06-2018
Publisher: Elsevier BV
Date: 05-2007
Publisher: Elsevier BV
Date: 04-1999
Publisher: Bentham Science Publishers Ltd.
Date: 11-2009
DOI: 10.2174/157016209789973655
Abstract: Stigma within health care settings poses a considerable barrier to the provision of treatment and care for patients with HIV/AIDS (PLWHA). Southern China is located in a region with one of the world's fastest growing HIV/AIDS epidemics. Attitudes towards PLWHA amongst health workers are currently under-researched in this region. This paper examines the inter-relationships between prejudicial attitudes among Chinese medical students towards HIV/AIDS and attitudes towards three risk behaviors: injecting drug use (IDU), commercial sex (CS) and commercial blood donation (CBD). Medical students (N = 352) in Guangzhou were presented with two random vignettes each describing a hypothetical male that was identical, except for the disease diagnosis (AIDS/leukemia) and the co-characteristic (IDU/CS/CBD/blood transfusion/no co-characteristic). After reading each vignette, participants completed a standard prejudicial scale. Univariate and multivariable analyses revealed significant levels of prejudice associated with AIDS, IDU and CS. Regardless of the disease, patients with IDU or CS were judged significantly worse than patients who had received a blood transfusion. No significant interactions were found between AIDS and the stigmatized co-characteristics. The findings suggest that prejudice towards PLWHA needs to be understood within the larger context of the stigma towards risk behaviors. Although non-significant interactions were found between AIDS and the stigmatized risk behaviors, the overlap between the local HIV/AIDS, IDU and CS populations suggests that addressing risk behavior-related prejudices could be critical for improving care and treatment for PLWHA.
Publisher: Elsevier BV
Date: 06-2018
DOI: 10.1016/J.JCLINEPI.2018.02.006
Abstract: To identify uses of WHO Model list of essential medicines (EMs) and summarize studies examining EM and national EM lists (NEMLs). In this scoping review, we searched PubMed, Scopus, WHO website and WHO Regional Databases for studies on NEMLs, reimbursement medicines lists, and WHO EML, with no date or language restrictions. Three thousand one hundred forty-four retrieved documents were independently screened by two reviewers 100 full-text documents were analyzed 37 contained data suitable for quantitative and qualitative analysis on EMs availability (11 documents), medicines for specific diseases (13 documents), and comparison of WHO EML and NEMLs (13 documents). From the latter, two documents analyzed the relevance of evidence from Cochrane systematic reviews for medicines that were on NEMLs but not on the WHO EML. EMs availability is still suboptimal in low-income countries. Availability of children formulations and EMs for specific diseases such as chronic, cancer, pain, and reproductive health is suboptimal even in middle-income countries. WHO EML can be used as a basic set of medicines for different settings. More evidence is needed into how NEMLs can contribute to better availability of children formulations, pain, and cancer medicines in developing countries.
Publisher: Public Library of Science (PLoS)
Date: 15-06-2015
Publisher: CSIRO Publishing
Date: 2008
DOI: 10.1071/FP08124
Abstract: Photoprotection, light harvesting and light utilisation were investigated as a function of variation in N supply and canopy position in 21-year-old Pinus radiata D. Don. Chlorophyll fluorescence, gas exchange and photoprotective compounds were measured on lower, middle and upper canopy needles in trees receiving N fertiliser and in control trees not receiving N fertiliser. Irrespective of canopy height, additional N increased the light-harvesting capacity through greater contents of chlorophyll, neoxanthin and lutein, but did not affect light-utilisation processes, such as effective quantum yield of PSII or rates of net CO2 assimilation. Additional N fertiliser did not affect the concentrations of the measured photoprotective carotenoids (violaxanthin, antheraxanthin, zeaxanthin, α-carotene and β-carotene) or antioxidants (ascorbic acid, glutathione and α-tocopherol) however, carotenoids and antioxidants were strongly affected by canopy height and increased in concentration with increasing canopy height. The present study found that pools of photoprotective carotenoids and antioxidants were not driven by imbalances in light-harvesting and light-utilisation processes, but rather by gradients in light.
Publisher: Wiley
Date: 06-2001
Publisher: Informa UK Limited
Date: 19-06-2014
DOI: 10.3109/15412555.2014.908834
Abstract: Chronic obstructive pulmonary disease (COPD) is among the leading causes of death globally, accounting for about 3 million deaths worldwide in 2011. We aimed to estimate the prevalence of COPD in Africa in the year 2010 to provide the information that could assist health policy in the region. We conducted a systematic review of Medline, EMBASE and Global Health for studies on COPD published between 1990 and 2012. We included original population based studies providing estimates of the prevalence of COPD. We considered the reported estimates in terms of the mean age of the s le, sex ratio, the year of study and the country of the study as possible covariates. RESULTS from two different types of studies, i.e., based on spirometric and non-spirometric diagnosis of COPD, were further compared. The United Nation Population Division's population figures were used to estimate the number of COPD cases in the year 2010. Our search returned 243 studies, from which only 13 met our selection criteria and only five were based on spirometry. The difference in the median prevalence of COPD in persons aged 40 years or older based on spirometry data (13.4% IQR: 9.4%-22.1%) and non-spirometry data (4.0% IQR: 2.1%-8.9%) was statistically significant (p = 0.001). There was no significant effect of the gender or the year of the study on the reported prevalence of COPD in either set of studies. The prevalence of COPD increased with age in spirometry-based studies (p = 0.017), which is a plausible finding suggesting internal consistency of spirometry-based estimates, while this trend was not observed in studies using other case definitions. When applied to the appropriate age group (40 years or more), which accounted for 196.4 million people in Africa in 2010, the estimated prevalence translates into 26.3 million (18.5-43.4 million) cases of COPD. Comparable figures for the year 2000 based on the same prevalence rates would amount to 20.0 million (14.1-33.1), suggesting an increase of 31.5% over a decade that is attributable to ageing of the African population alone. Our findings suggest that COPD is likely to already represent a very large public health problem in Africa. Moreover, rapidly ageing African population should expect a steady increase in the number of COPD cases in the next decade and beyond. The quantity and quality of available evidence does not match the size of the problem. There is a need for more research on COPD prevalence, but also incidence, mortality and risk factors in Africa. We hope this study will raise awareness of COPD in Africa and encourage further research.
Publisher: International Society of Global Health
Date: 06-2014
Publisher: Wiley
Date: 06-2001
Publisher: International Global Health Society
Date: 06-2018
Publisher: Elsevier BV
Date: 11-2008
Publisher: Croatian Medical Journals
Date: 12-2008
Publisher: Mary Ann Liebert Inc
Date: 10-2007
Abstract: There is currently a scarcity of research on the nature of HIV/AIDS stigma within the Thai health context. This is problematic given the negative role of stigma in hindering the provision of patient care and treatment. This study used a mixed-method approach to investigate the interrelationships between the stigma of HIV/AIDS and the stigmas relating to its various modes of disease transmission including injection drug use (IDU). Twenty interviews were conducted with trainees and qualified nurses from a Bangkok college. Participants were presented with vignettes describing a hypothetical person varying in disease diagnoses (AIDS, leukemia, no disease) and co-characteristics (IDU, commercial sex (CS), blood transfusion, no co-characteristic). Using a Q-sort task, participants arranged the vignettes along a bipolar scale according to their willingness to interact with the persons, and were asked to explain their decisions. Univariate and multivariate regression analyses showed that IDU, AIDS, and CS were all in idually stigmatizing. Strong interactions were found between the stigmas of HIV/AIDS, IDU, and CS. Interview data also showed clear biases toward patients according to their IDU and CS habits. The findings suggest that addressing these co-stigmas could be vital to the success of efforts aimed at reducing the disease stigma of HIV/AIDS.
Publisher: Elsevier BV
Date: 02-2000
Publisher: Public Library of Science (PLoS)
Date: 04-01-2011
Publisher: Springer Science and Business Media LLC
Date: 2006
Publisher: Springer Science and Business Media LLC
Date: 2001
Abstract: In previous work, we provided evidence from sap flow measurements that when root systems span soil layers of different moisture content, water is redistributed by roots in the direction of the difference in water potential. In addition to the phenomenon termed "hydraulic lift", where water is redistributed from depth to dry topsoil, the process of "hydraulic redistribution" includes downward transfer of water when the surface layers of soils with low permeability become wet after rainfall. In this paper, we support our previous findings with evidence from measurements of soil water and estimate the quantities of water transferred to depth following rain. Amounts of water stored at depth are not likely to be significant for drought avoidance by plants. However, downward transfer of water may be important to plant establishment and the reduction of waterlogging in certain soil types.
Publisher: CSIRO Publishing
Date: 2002
DOI: 10.1071/EA02012
Abstract: This paper examines the effect severing lateral tree roots (root pruning) has on crop and tree growth and soil water content at 2 sites in the south-west of Western Australia. Crop and tree growth and soil water content were assessed in a Pinus pinaster windbreak system growing on 0.45–1.00 m of sand over clay, and crop growth was assessed adjacent to Eucalyptus globulus windbreaks growing on 4–5 m of sand. Crop yield was depressed by 23–52% within 2.5 times the tree height (H) of unpruned pines and by 44% within 2.5 H of pruned eucalypts. Depressed yields made cropping uneconomical within 1.5 H of the eucalypts and 1 H of the pines. Root pruning most improved crop yields where lateral tree roots were confined close to the soil surface and decreased in effectiveness as the depth to confining layer (clay) increased. Crop losses within 2.5 H of the pines were reduced from 39 to 14% in the year the trees were root pruned and were 25% 1 year after root pruning. Subsequent root pruning of the eucalypts did not improve crop yield. While root pruning severed lateral pine roots, tree growth was not significantly reduced. The principal cause of reduced crop yield near the trees appeared to be reduced soil moisture in the area occupied by tree roots. Competition for nutrients and light appeared to have little effect on crop yield. Root pruning can spatially separate tree and crop roots where the tree roots are confined close to the surface, and significantly improve crop yields without reducing tree growth.
Publisher: Elsevier BV
Date: 02-2017
Publisher: Public Library of Science (PLoS)
Date: 11-01-2011
Publisher: Wiley
Date: 09-2000
Publisher: Springer Science and Business Media LLC
Date: 09-03-2006
DOI: 10.1007/S00425-006-0247-7
Abstract: In previous studies, water stress has induced variable and sometimes contradictory changes in respiration. We used isothermal calorimetry to measure the response of foliar respiration to water deficit in nine eucalypt genotypes. Specific growth rates (R(SG)) of shoots and leaves of variable age were measured independently, and the data were applied to both the growth-maintenance and enthalpy balance models. We calculated the oxidation state of respiratory substrate and the enthalpy change for the conversion of substrate carbon to biomass (DeltaH(B)). Moderate water stress reduced the R(SG) of shoots by 38% (P<0.01) and carbon conversion efficiency by 15% (P<0.05). The relationship between carbon conversion efficiency and R(SG) was not affected by water deficit for shoots, but was significantly altered for leaves. Water deficit increased maintenance respiration by about 23% (P<0.001). The growth coefficient of respiration was not significantly altered. However, changes in oxidation states of substrate and biomass suggest that the energy requirements of biosynthesis were increased under water stress. Our results confirm that carbohydrates are the major respiratory substrates in growing tissues, though mature leaves utilized a substantial component of more reduced substrate. Mature leaves had variable oxidation states for respiration substrate, which indicates a variable relationship between CO(2) evolution and ATP production. Measured DeltaH(B) in shoots and leaves were too small for reliable estimation of R(SG) by the enthalpy balance model. We also found significant effects of water stress on the oxidation state of substrate and DeltaH(B).
Publisher: Wiley
Date: 24-10-2006
Publisher: Wiley
Date: 21-08-2006
Publisher: Elsevier BV
Date: 2015
Publisher: International Society of Global Health
Date: 16-04-2018
Publisher: Wiley
Date: 16-06-2007
Publisher: Public Library of Science (PLoS)
Date: 22-09-2011
Publisher: Public Library of Science (PLoS)
Date: 03-09-2013
Publisher: Wiley
Date: 06-2015
DOI: 10.1002/WPS.20222
Publisher: Springer Science and Business Media LLC
Date: 12-2012
Abstract: There is, globally, an often observed inequality in the health services available in urban and rural areas. One strategy to overcome the inequality is to require urban doctors to spend time in rural hospitals. This approach was adopted by the Beijing Municipality (population of 20.19 million) to improve rural health services, but the approach has never been systematically evaluated. Drawing upon 1.6 million cases from 24 participating hospitals in Beijing (13 urban and 11 rural hospitals) from before and after the implementation of the policy, changes in the rural–urban hospital performance gap were examined. Hospital performance was assessed using changes in six indices over-time: Diagnosis Related Groups quantity, case-mix index (CMI), cost expenditure index (CEI), time expenditure index (TEI), and mortality rates of low- and high-risk diseases. Significant reductions in rural–urban gaps were observed in DRGs quantity and mortality rates for both high- and low-risk diseases. These results signify improvements of rural hospitals in terms of medical safety, and capacity to treat emergency cases and more erse illnesses. No changes in the rural–urban gap in CMI were observed. Post-implementation, cost and time efficiencies worsened for the rural hospitals but improved for urban hospitals, leading to a widening rural–urban gap in hospital efficiency. The strategy for reducing urban–rural gaps in health services adopted, by the Beijing Municipality shows some promise. Gains were not consistent, however, across all performance indicators, and further improvements will need to be tried and evaluated.
Publisher: International Global Health Society
Date: 12-2017
Publisher: International Global Health Society
Date: 12-2017
Publisher: Wiley
Date: 06-11-2008
DOI: 10.1111/J.1469-8137.2008.02601.X
Abstract: Correlation methods originating in the growth and maintenance paradigm (GMP) are traditionally used to calculate a 'growth coefficient' (g) or the 'growth potential' (1/g) of entire plants. The enthalpy balance approach is usually applied to plant organs and relies on determination of both CO(2) release and O(2) reduction to provide a measure of instantaneous rates of enthalpic growth (R(SG)DeltaH(B)). Aspects of both the approaches to explore physiological mechanisms that govern enthalpic growth (variation in rates of CO(2) release versus rates of O(2) reduction) were combined. Respiration and growth rates of apical buds of Pinus radiata were affected strongly by canopy position, and moderately by branching order. A linear relation between enthalpic growth and CO(2) respiration explained 69% of the observed variation. Despite faster rates of growth, enthalpic growth potential (1/g(H)) was comparatively low in the upper canopy. Low enthalpic growth potential entailed comparatively low enthalpy conversion efficiency (eta(H), ratio of R(SG)DeltaH(B) to R(CO(2)) DeltaH(CO(2)) proportional to CO(2):O(2) and to carbon conversion efficiency epsilon) at large R(SG)DeltaH(B). Maximizing enthalpic growth requires a large capacity for O(2) reduction. Relations between R(SG)DeltaH(B) and eta(H) could be described by hyperbolae using two parameters. One parameter, P(1), is equivalent to enthalpic growth potential (1/g(H)).
Publisher: Wiley
Date: 07-2001
DOI: 10.1055/S-2001-16454
Publisher: International Global Health Society
Date: 12-2017
Publisher: The Company of Biologists
Date: 2017
DOI: 10.1242/BIO.028605
Abstract: Fibroblast growth factor (FGF) morphogen signalling through the evolutionarily ancient Extracellular signaling Regulated Kinase/Mitogen Activated Protein Kinase (ERK/MAPK) pathway recurs in many neural and non-neural developmental contexts and understanding the mechanisms that regulate FGF/ERK function are correspondingly important. The glycosaminoglycan heparan sulphate (HS) binds to FGFs and exists in an enormous number of differentially sulphated forms produced by the action of HS modifying enzymes so has the potential to present an extremely large amount of information in FGF/ERK signalling. Although there have been many studies demonstrating that HS is an important regulator of FGF function, experimental evidence on the role of the different HS modifying enzymes on FGF gradient formation has been lacking until now. We challenged ex vivo developing mouse neural tissue in which HS had either been enzymatically removed by heparanase treatment or lacking either the HS modifying enzymes Hs2st (Hs2st−/− tissue) or Hs6st1 (Hs6st1−/− tissue) with exogenous Fgf8 to gain insight on how HS and the function of these two HS modifying enzymes impacts on Fgf8 gradient formation from an exogenously supplied source of Fgf8 protein. We discover that two different HS modifying enzymes, Hs2st and Hs6st1, indeed differentially modulate the properties of emerging Fgf8 protein concentration gradients and the Erk signalling output in response to Fgf8 in living tissue in ex vivo cultures. Both Hs2st and Hs6st1 are required for stable Fgf8 gradients to form as rapidly as they do in wild-type tissue while only Hs6st1 has a significant effect on suppressing the levels of Fgf8 protein in the gradient compared to wild-type. Next we show that Hs2st and Hs6st1 act to antagonise and agonise the Erk signalling in response to Fgf8 protein respectively in ex vivo cultures of living tissue. Examination of endogenous Fgf8 protein and Erk signalling outputs in Hs2st−/− and Hs6st1−/− embryos suggests that our ex vivo findings have physiological relevance in vivo. Our discovery identifies a new class of mechanism to tune Fgf8 function by regulated expression of Hs2st and Hs6st1 that is likely to have broader application to the & other signaling proteins that interact with HS and their function in neural development and disease.
Publisher: International Global Health Society
Date: 12-2017
Publisher: International Global Health Society
Date: 09-11-2018
Publisher: Wiley
Date: 23-09-2006
DOI: 10.1111/J.1365-3040.2005.01412.X
Abstract: Central paradigms of ecophysiology are that there are recognizable and even explicit and predictable patterns among species, genera, and life forms in the economics of water and nitrogen use in photosynthesis and in carbon isotope discrimination (delta). However most previous examinations have implicitly assumed an infinite internal conductance (gi) and/or that internal conductance scales with the biochemical capacity for photosynthesis. Examination of published data for 54 species and a detailed examination for three well-characterized species--Eucalyptus globulus, Pseudotsuga menziesii and Phaseolus vulgaris--show these assumptions to be incorrect. The reduction in concentration of CO2 between the substomatal cavity (Ci) and the site of carbon fixation (Cc) varies greatly among species. Photosynthesis does not scale perfectly with gi and there is a general trend for plants with low gi to have a larger draw-down from Ci to Cc, further confounding efforts to scale photosynthesis and other attributes with gi. Variation in the gi-photosynthesis relationship contributes to variation in photosynthetic 'use' efficiency of N (PNUE) and water (WUE). Delta is an information-rich signal, but for many species only about two-thirds of this information relates to A/gs with the remaining one-third related to A/gi. Using data for three well-studied species we demonstrate that at common WUE, delta may vary by up to 3 per thousand. This is as large or larger than is commonly reported in many interspecific comparisons of delta, and adds to previous warnings about simplistic interpretations of WUE based on delta. A priority for future research should be elucidation of relationships between gi and gs and how these vary in response to environmental conditions (e.g. soil water, leaf-to-air vapour pressure deficit, temperature) and among species.
Publisher: International Global Health Society
Date: 06-2016
Publisher: Elsevier BV
Date: 04-2007
Publisher: Elsevier BV
Date: 11-2000
Publisher: International Global Health Society
Date: 06-2016
Publisher: Elsevier BV
Date: 06-2004
Publisher: Informa UK Limited
Date: 07-2005
DOI: 10.1080/09540120500120195
Abstract: This paper outlines a six-country study of institutionalised forms of HIV/AIDS-related discrimination in the Asia-Pacific region. Although recognised as a barrier to disease prevention and treatment, very limited data are available on the effects of institutionalised HIV-related stigma and discrimination. Understanding the forms of discrimination within the institutions where they occur is the first step to identifying effective ways of promoting compassionate, non-discriminatory treatment of PLWHA. Thus, the goal of this research project was to document institutional discrimination against PLWHA, as guided by the UNAIDS Protocol for the Identification of Discrimination Against People Living with HIV (2000), in six Asian countries: India, Thailand, Philippines, China, Vietnam and Indonesia. As a precursor to the six in idual studies, this paper provides a brief overview of the literature on HIV discrimination, and then describes the UNAIDS Protocol and the shared methodological considerations relevant to all of the study sites. Commonalities in s ling, procedures and analysis are also discussed.
Publisher: Elsevier BV
Date: 11-1998
DOI: 10.1016/S0039-9140(98)00170-2
Abstract: A flow injection analysis of Ca(2+) and Mg(2+) using indirect potentiometric detection in natural waters is proposed, where Ca(2+) or Mg(2+) are injected into a buffer carrier containing phosphate, resulting in the formation of Ca(3)(PO(4))(2) or Mg(3)(PO(4))(2). The consequent reduction in free phosphate in the carrier solution is detected using a metallic cobalt wire electrode. Indirect electrode response was used and the experimental conditions affecting electrode response were optimized. Responses were linear in the concentration range 5x10(-4) to 5x10(-3) M with a detection limit of 1x10(-5) M in 20 mM phosphate buffer at pH 8.0. The relative standard derivation at 1 mM of Ca(2+) and Mg(2+) were 3.9 and 3.7% (n=10), respectively. EGTA and 8-hydroxyquinoline were used as the masking agents for Ca(2+) and Mg(2+), respectively. Concentrations of Ca(2+) and Mg(2+) in natural waters were successfully determined by the proposed method.
Publisher: Elsevier BV
Date: 11-2016
Publisher: Croatian Medical Journals
Date: 12-2013
Publisher: Public Library of Science (PLoS)
Date: 30-01-2007
Publisher: Elsevier BV
Date: 07-2010
Publisher: Canadian Science Publishing
Date: 04-2002
DOI: 10.1139/X01-225
Abstract: We investigated possible causes of slower growth of Pinus pinaster Ait. supplied with nitrate, as compared with ammonium or with ammonium nitrate mixtures. Six-month-old mycorrhizal seedlings of P. pinaster were grown in sand culture for 4 months at four concentrations of N (0.125, 0.5, 2.0, or 8.0 mM) as nitrate or ammonium or with an ammoniumnitrate mixture at 0.125 or 2.0 mM. After 4 months of nutrient addition, we measured light-saturated rates of photosynthesis (A max ), rates of ammonium and nitrate uptake, growth, macro- and micro-elements, and patterns of N allocation in needles. Dry mass was unaffected by N form at 0.125 or 0.5 mM N. In contrast, dry mass of seedlings supplied with ammonium or ammonium nitrate at 2.0 and 8.0 mM N, was approximately threefold greater than seedlings supplied with nitrate alone. Concentrations of N in foliage and A max were unaffected by the form or concentration of N supplied. Furthermore, concentrations of amino acid N were greater in seedlings supplied with nitrate, suggesting rates of uptake were not limiting growth. Foliage concentrations of zinc were low with nitrate supplied at a concentration of 0.5 mM or greater, and seedlings displayed symptoms typical of zinc deficiency when nitrate was supplied at 2.0 or 8.0 mM. Slower growth with nitrate could not be explained solely by either slower root uptake of nitrate N or lesser A max . Instead, aspects of N metabolism postuptake coupled with other factors such as nutrient deficiencies may limit growth with nitrate as the sole N source.
Publisher: Springer Science and Business Media LLC
Date: 05-2001
Abstract: The stable C isotope composition (δ
Publisher: International Global Health Society
Date: 13-10-2018
Publisher: Elsevier BV
Date: 2002
Publisher: International Global Health Society
Date: 15-11-2017
Publisher: Elsevier BV
Date: 06-2013
Publisher: Wiley
Date: 27-03-2008
DOI: 10.1111/J.1365-3040.2008.01808.X
Abstract: We showed that temperature responses of dark respiration for foliage of Pinus radiata could be approximated by Arrhenius kinetics, whereby E(0) determines shape of the exponential response and denotes overall activation energy of respiratory metabolism. Reproducible and predictable deviation from strict Arrhenius kinetics depended on foliage age, and differed between R(CO2) and R(O2). Inhibition of oxygen reduction (R(O2)) by cyanide (inhibiting COX) or SHAM (inhibiting AOX) resulted in reproducible changes of the temperature sensitivity for R(O2), but did not affect R(CO2). Enthalpic growth--preservation of electrons in anabolic products--could be approximated with knowledge of four variables: activation energies (E(0)) for both R(CO2) and R(O2), and basal rates of respiration at a low reference temperature (R(REF)). Rates of enthalpic growth by P. radiata needles were large in spring due to differences between R(REF) of oxidative decarboxylation and that of oxygen reduction, while overall activation energies for the two processes were similar. Later during needle development, enthalpic growth was dependent on differences between E(0) for R(CO2) as compared with R(O2), and increased E(0)(R(O2)) indicated greater contributions of cytochrome oxidase to accompany the switch from carbohydrate sink to source. Temperature-dependent increments in stored energy can be calculated as the difference between R(CO2)DeltaH(CO2) and R(O2)DeltaH(O2).
Publisher: International Global Health Society
Date: 12-2015
Publisher: Informa UK Limited
Date: 07-2005
DOI: 10.1080/09540120500119874
Abstract: This paper presents key findings of a situational analysis of institutional and structural levels of HIV/AIDS-related discrimination in Beijing, China, with a focus on the area of health care. Initially slow to respond to the presence of HIV, China has altered its approach and enacted strict legislative protection for people living with HIV/AIDS (PLWHA). In order to determine whether this has altered discrimination against PLWHA, this study examined existing legislation and policy, and interviewed key informants working in health care and PLWHA. The overall findings revealed that discrimination in its many forms continued to occur in practice despite China's generally strong legislative protection, and it is the actual practice that is hindering PLWHAs' access to health services. A number of legislative and policy gaps that allow discrimination to occur in practice were also identified and discussed. The paper concludes with a call to rectify specific gaps between legislation, policy and practice. An understanding of the underlying factors that drive discrimination will also be necessary for effective strategic interventions to be developed and implemented.
Publisher: Wiley
Date: 28-04-2006
Publisher: Wiley
Date: 19-07-2004
Publisher: Wiley
Date: 11-2007
DOI: 10.2134/JEQ2007.0175
Abstract: Managed forests and plantations are appropriate ecosystems for land-based treatment of effluent, but concerns remain regarding nutrient contamination of ground- and surface waters. Monthly NO3-N and NH4-N concentrations in soil water, accumulated soil N, and gross ammonification and nitrification rates were measured in the second year of a second rotation of an effluent irrigated Eucalyptus globulus plantation in southern Western Australia to investigate the separate and interactive effects of drip and sprinkler irrigation, effluent and water irrigation, irrigation rate, and harvest residues retention. Nitrate concentrations of soil water were greater under effluent irrigation than water irrigation but remained <15 mg L(-1) when irrigated at the normal rate (1.5-2.0 mm d(-1)), and there was little evidence of downward movement. In contrast, NH4-N concentrations of soil water at 30 and 100 cm were generally greater under effluent irrigation than water irrigation when irrigated at the normal rate because of direct effluent NH4-N input and indirect ammonification of soil organic N. Drip irrigation of effluent approximately doubled peak NO3-N and NH4-N concentrations in soil water. Harvest residue retention reduced concentrations of soil water NO3-N at 30 cm during active sprinkler irrigation, but after 1 yr of irrigation there was no significant difference in the amount of N stored in the soil system, although harvest residue retention did enhance the "nitrate flush" in the following spring. Gross mineralization rates without irrigation increased with harvest residue retention and further increased with water irrigation. Irrigation with effluent further increased gross nitrification to 3.1 mg N kg(-1) d(-1) when harvest residues were retained but had no effect on gross ammonification, which suggested the importance of heterotrophic nitrification. The downward movement of N under effluent irrigation was dominated by NH4-N rather than NO3-N. Improving the capacity of forest soils to store and transform N inputs through organic matter management must consider the dynamic equilibrium between N input, uptake, and immobilization according to soil C status, and the effect changing microbial processes and environmental conditions can have on this equilibrium.
Publisher: Canadian Science Publishing
Date: 08-2007
DOI: 10.1139/X06-314
Abstract: Respiration rate and efficiency in growing tissues are major determinants of plant growth. We measured apical shoot respiration and tree growth in 3-year-old clones of Eucalyptus camaldulensis Dehnhardt × Eucalyptus grandis W. Hill ex Maid. and Eucalyptus camaldulensis × Eucalyptus globulus Labill. Respiration was measured by isothermal calorimetry and the oxidation state of newly formed biomass was determined by elemental analysis. We found that the enthalpy change due to conversion of carbon substrate to biomass was too small for determining specific growth rate by an enthalpy balance model of respiration and growth. Negative phenotypic correlations were significant between respiration rate and basal area, height, volume, and volume growth. Genetic correlations between respiration rate and tree size or growth were mostly significant and estimates ranged from –0.55 to –1.02. Repeatability of the clone means was around 0.80 for respiration rate, 0.71–0.91 for summer growth, and in excess of 0.80 for tree size traits. The intraclass correlation for clones (within families) was 0.33 for rate of CO 2 evolution and 0.45 for rate of metabolic heat evolution. Our results suggest considerable potential for altering respiration rate in breeding populations by selection, although the mechanisms linking respiration with growth require further investigation.
Publisher: Springer Science and Business Media LLC
Date: 2004
Publisher: Wiley
Date: 09-12-2005
DOI: 10.1111/J.1469-8137.2004.01232.X
Abstract: Responses to simulated sunflecks were examined in upper canopy and coppice leaves of Nothofagus cunninghamii growing in an old-growth rainforest gully in Victoria, Australia. Shaded leaves were exposed to a sudden increase in irradiance from 20 to 1500 micromol m(-2) s(-1). Gas exchange and chlorophyll fluorescence were measured during a 10 min simulated sunfleck and, in the ensuing dark treatment, we examined the recovery of PS II efficiency and the conversion state of xanthophyll cycle pigments. Photosynthetic induction was rapid compared with tropical and northern hemisphere species. Stomatal conductance was relatively high in the shade and stomata did not directly control photosynthetic induction under these conditions. During simulated sunflecks, zeaxanthin was formed rapidly and photochemical efficiency was reduced. These processes were reversed within 30 min in coppice leaves, but this took longer in upper canopy leaves. Poor drought tolerance and achieving a positive carbon balance in a shaded canopy may be functionally related to high stomatal conductance in the shade in N. cunninghamii. The more persistent reduction in photochemical efficiency of upper canopy leaves, which means less efficient light use in subsequent shade periods, but stronger protection from high light, may be related to the generally higher irradiance and longer duration of sunflecks in the upper canopy, but potentially reduces carbon gain during shade periods by 30%.
Publisher: Elsevier BV
Date: 05-1998
Publisher: Elsevier BV
Date: 08-2000
Publisher: MDPI AG
Date: 21-11-2013
DOI: 10.3390/NU5114715
Publisher: Springer Science and Business Media LLC
Date: 18-07-2007
DOI: 10.1007/S00442-007-0803-2
Abstract: Two of the ways in which plants cope with water deficits are stomatal closure and "osmotic adjustment". We sought to assess the contributions of these processes to maintenance of leaf hydration in field-grown, 7-year-old Eucalyptus marginata. Plants were exposed to their normal summer drought (controls) or supplied with additional water (irrigated). Irrigation increased photosynthesis by 30% in E. marginata. These increases in photosynthesis were related to an 80% increase in g (s). However, there was no difference in substomatal CO(2) concentrations between treatments, or in chloroplast CO(2) concentrations, as indicated by carbon isotope composition of leaf soluble sugars. This suggests that impaired mesophyll metabolism may partially explain slower rates of photosynthesis in plants exposed to their normal summer drought. There was no difference in concentrations of solutes or osmotic potential between non-irrigated and irrigated in iduals, perhaps because relative water content was the same in non-irrigated and irrigated plants due to stomatal sensitivity to water deficits. Irrespective of the absence of osmotic adjustment, analysis of leaf solutes gave a clear indication of the major groups of compounds responsible for maintaining cell osmotic potential. Soluble sugars were three times as abundant as amino acids. Proline, a putatively osmotically active amino acid, contributed less than 1% of total solutes. These patterns of solutes in E. marginata are consistent with a growing body of literature arguing a greater role for carbohydrates and cyclitols and lesser role for amino acids in maintaining osmotic potential. Our data suggest the primary mechanism by which E. marginata coped with drought was partial stomatal closure however, we cannot discount the possibility of osmotic adjustment under more severe water deficits.
Publisher: Public Library of Science (PLoS)
Date: 07-05-2015
Publisher: Springer Science and Business Media LLC
Date: 05-0004
DOI: 10.1007/BF02467748
Publisher: CSIRO Publishing
Date: 2004
DOI: 10.1071/FP04115
Abstract: Species originating from xeric sites are characterised by slower rates of photosynthesis per unit nitrogen (PNUE) than species from mesic sites, but we lack mechanistic explanations for these interspecific differences. We examined N allocation to Rubisco and chlorophyll, and photosynthetic characteristics in seedlings of nine Eucalyptus species grown in a fully sunlit glasshouse with an optimal supply of nutrients. Species were selected from mesic (1800 mm year–1 rainfall) through to semi-arid habitats (300 mm year–1). All species were characterised by allocation of a large proportion of N to Rubisco (32–48%) with high in vivo specific activity. Intercellular CO2 concentration (Ci) varied between 260 and 300 μmol mol–1, and thus, stomatal limitations were low in all species. This combination of traits resulted in a PNUE (172–335 μmol mol–1 s–1) that was higher than is commonly observed in tree species and which may be related to the rapid growth, water-spender strategy of Eucalyptus seedlings. There were significant differences in photosynthetic parameters and N allocation among species, but these were only weakly related to rainfall at the site of seed origin. There were correlations of Ci with PNUE but a sensitivity analysis suggested that interspecific variation in Ci explained at most 7% of variation in PNUE. Photosynthesis and PNUE were also rather insensitive to large interspecific differences in RuBP-limited rate of electron transport per unit N (Jmax / N), because photosynthesis was primarily limited by the maximum rate of carboxylation (Vcmax). PNUE was most sensitive to changes in N allocation to Rubisco and Vcmax / Rubisco.
Publisher: Elsevier BV
Date: 06-1998
Abstract: The simultaneous determination of amino and organic acids in plant tissue extracts using capillary gas chromatography is described. Plant leaves were extracted in 5% (w/v) perchloric acid and neutralized extracts were purified using C18 cartridges. The amino and organic acids in purified extracts were then converted to tert-butyldimethylsilyl (TBDMS) derivatives prior to separation and detection by capillary gas chromatography (GC) with flame ionization detection. Conditions required for optimal derivatization were investigated. Amino and organic acids were readily converted to their TBDMS derivatives using N-methyl-N-tert-butyldimethylsilyltrifluoroacetamide in dimethylformamide solvent 1:6 (v/v) with an average recovery of 90% and a reproducibility of about 5%. The characteristic [M-57] and [M-159] fragment ion of the TBDMS derivatives was confirmed using GC-MS. The proposed method was demonstrated by the determination of amino and organic acids in extracts of Acacia and Eucalyptus leaves, where detection limits were 1-20 ng.
Publisher: Wiley
Date: 03-03-2006
Publisher: Elsevier BV
Date: 07-2001
Publisher: Health Affairs (Project Hope)
Date: 12-2010
DOI: 10.1377/HLTHAFF.2009.0989
Abstract: Reducing the gap in health outcomes between rural and urban areas in China has been a focus of the central government's health reform efforts since 2002. Drawing on national survey data from 2003 and 2008, this paper analyzes changes in the rural-urban gap for patients with chronic diseases. Overall, there were substantial improvements at the national level in insurance coverage and the use of hospital services for both urban and rural residents with chronic diseases. There was also an overall reduction in the rural-urban gap in the use of inpatient services. But the gains were uneven. For ex le, although rural Chinese with chronic disease could more easily start inpatient treatment in 2008 than they could in 2003, because of the higher hospital copayments required under insurance coverage for rural citizens, they were more than twice as likely to drop out of treatment as were Chinese in urban areas. The strongest evidence of the narrowing of the rural-urban gap came from central China, while the evidence is mixed for western and eastern China. Our analysis suggests that different approaches will be required to narrow the rural-urban health service gap in different regions of China.
Publisher: Wiley
Date: 2004
DOI: 10.1002/PCA.801
Abstract: Capillary electrophoresis methods are described for the analysis of the major inorganic anions (nitrite, nitrate, chloride, sulphate, phosphate), organic acids (oxalate, malate, citrate, succinate) and inorganic cations (ammonium, potassium, sodium, calcium, magnesium) in leaf extracts. Analytical performance was validated for extracts from leaves of four sclerophyllous species: Eucalyptus globulus, E. cladocalyx, E. nitens and Pinus radiata. Inorganic anions and organic acids were analysed in a single run within 5 min using a background electrolyte of 2,6-pyridinedicarboxylic acid (20 mM) and cetyltrimethylammonium bromide (0.5 mM). Cations were analysed in a separate run also within 5 min using imidazole (10 mM) and 18-crown-6 (2 mM) as background electrolyte. Replicate injections were highly repeatable when the capillary was rinsed between runs with hydrochloric acid (0.25 M) and background electrolyte, but not when the acid rinse was omitted or replaced by a rinse with sodium hydroxide (0.25 M). Standard curves for all analytes were linear over the range of 0.05-1 mm. Standard curves constructed by serial dilution of a leaf extract were also highly linear, and this, combined with the excellent recovery of added solutes in a spike and recovery test, suggests quantification was unaffected by the complex matrix that is present in un-purified, hot water extracts of leaves. There were significant differences in concentrations of the major anions and cations between the species studied.
Publisher: Elsevier
Date: 2008
Publisher: Wiley
Date: 10-08-2006
DOI: 10.1111/J.1365-3040.2006.01577.X
Abstract: In many tree species, physiological adaptations to drought include the accumulation of osmotically active substances and/or the presence of particular compatible solutes, among them cyclitols. Recently, the cyclitol quercitol was identified in species of Eucalyptus, a erse genus whose speciation is probably driven by adaptation to water availability. We subjected seedlings of 13 Eucalyptus species from different ecosystems ('mesic' and 'xeric') and different sub-generic taxonomic groups to 10 weeks of water deficit (WD) treatment. Pre-dawn water potentials (psi(pdwn)) and relative water content (RWC) were determined in shoots, and total osmolality, soluble low-molecular-weight carbohydrates and cyclitols were measured in leaves and roots. Responses to water deficit followed two distinct patterns: Eucalyptus species from 'mesic' environments adjusted concentrations of sucrose (through increased levels of sucrose and decreases in RWC) in response to water deficit, whereas 'xeric' species increased concentrations of quercitol (through reductions in RWC). In root tissues, only species from xeric environments contained high levels of quercitol and mannitol, increasing under WD conditions. We suggest that the former (mesic) strategy may be beneficial to respond to short-lasting drought conditions, because sucrose is easily metabolized, whereas the latter (xeric) strategy may relate to an effective acclimation to longer-lasting drought. These physiological response groups are also related to taxonomic groups within the genus.
Publisher: International Global Health Society
Date: 12-2019
Publisher: International Global Health Society
Date: 06-2017
Publisher: Elsevier BV
Date: 2003
Publisher: Oxford University Press (OUP)
Date: 12-02-2018
DOI: 10.1093/IJE/DYY007
Publisher: Wiley
Date: 27-03-2008
DOI: 10.1111/J.1365-3040.2008.01809.X
Abstract: Using an exponential model that relies on Arrhenius kinetics, we explored Type I, Type II and dynamic (e.g. declining Q(10) with increasing temperature) responses of respiration to temperature. Our Arrhenius model provides three parameters: R(REF) (the base of the exponential model, nmol g(-1) s(-1)), E(0) (the overall activation energy of oxygen reduction that dominates its temperature sensitivity, kJ mol(-1)) and delta (that describes dynamic responses of E(0) to measurement temperature, 10(3) K(2)). Two parameters, E(0) and delta, are tightly linked. Increases in overall activation energy at a reference temperature were inversely related to changes in delta. At an E(0) of ca. 45 kJ mol(-1), delta approached zero, and respiratory temperature response was strictly Arrhenius-like. Physiologically, these observations suggest that as contributions of AOX to combined oxygen reduction increase, E(0)(REF) decreases because of different temperature sensitivities for V(max), and delta increases because of different temperature sensitivities for K(1/2) of AOX and COX. The balance between COX and AOX activity helps regulate plant metabolism by adjusting the demand for ATP to that for reducing power and carbon skeleton intermediates. Our approach enables determination of respiratory capacity in vivo and opens a path to development of process-based models of plant respiration.
Publisher: Informa UK Limited
Date: 07-2005
DOI: 10.1080/09540120500120005
Abstract: There is scant research into HIV discrimination, particularly structural and institutional forms of it. This appears, in part, to arise from a prevailing view that the solutions to HIV discrimination are known a priori and in the absence of additional data. The six country studies into HIV discrimination presented in this AIDS Care supplement suggest that this is not the case. There needs to be an acceptance that if the issue of HIV discrimination is to be tackled successfully and based on evidence, then incremental and effortful steps need to be taken to develop that evidence base. This is discussed.
Publisher: Informa UK Limited
Date: 1999
Publisher: Elsevier BV
Date: 11-2009
Publisher: Elsevier BV
Date: 08-1998
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 2009
Publisher: Elsevier BV
Date: 04-2007
Publisher: International Global Health Society
Date: 29-11-2018
Publisher: Informa UK Limited
Date: 05-2009
DOI: 10.1080/13691050802621161
Abstract: This paper examines the culturally shaped meanings of AIDS and perceptions of accidental occupational exposure to HIV among a group of twenty nurses in Bangkok, Thailand. The findings are based on data collected as a part of a larger mixed-methods study that examined how perceptions of risk behaviours (including sexual promiscuity) shape health workers' perceptions of patients living with HIV/AIDS. Nurses' narratives revealed that despite acknowledgement of the low probability of occupational exposure to HIV, the fear of HIV infection remained and was largely driven by the enormity of the anticipated social (rather than the health) consequences of being HIV-positive. The perceived certainty of social ostracism was reinforced by participants' observations of the social rejection experienced by people living with HIV/AIDS both within and outside clinical settings. For female nurses, the dominant social perception that women living with HIV/AIDS were violators of gender norms, and thus 'guilty' victims, was an issue central to their self-identities. Ways of improving care for people living with HIV in the light of the nurses' concerns and future research are discussed.
Publisher: International Global Health Society
Date: 26-09-2018
Publisher: Wiley
Date: 05-11-2004
Location: United Kingdom of Great Britain and Northern Ireland
No related grants have been discovered for Kit Yee Chan.