338 research outputs found
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Standardization of procurement: National or international?
The ISO has issued a Draft International Standard on construction procurement and the British Standards Institute is drafting a standard based upon this for use in the UK. Three questions arise from these observations. First, what kind of consultation processes would be adequate to ensure that such a standard meets the requirements of an industry as diverse as construction? Second, why would an international standard be inappropriate for use in a country like UK? Third, what sort of issues should such a standard seek to cover? There are strong precedents for process standards, such as quality assurance, design management and workmanship on building sites. So the idea of a standard on procurement is not unusual. Moreover, there are many differences in tendering and procurement practice that are wasteful and even collusive or illegal. These issues are explored with a view to offering insights and suggestions for guidance based on the experiences in UK. The research method is first-hand observation of the drafting committee who are dealing with the British Standard. As an example to test and inform the standardization concept, six different standard guidance documents on tendering procedures are compared. This reveals a significant degree of diversity, and based on this, nine stages for implementing a tendering procedure are derived
Synthesis, analysis and biological evaluation of novel indolquinonecryptolepine analogues as potential anti-tumour agents.
A small library of cryptolepine analogues were synthesised incorporating halogens and/or nitrogen containing side chains to optimise their interaction with the sugar-phosphate backbone of DNA to give improved binding, interfering with topoisomerase II hence enhancing cytotoxicity. Cell viability, DNA binding and Topoisomerase II inhibition is discussed for these compounds. Fluorescence microscopy was used to investigate the uptake of the synthesised cryptolepines into the nucleus. We report the synthesis and anti-cancer biological evaluation of nine novel cryptolepine analogues, which have greater cytotoxicity than the parent compound and are important lead compounds in the development of novel potent and selective indoloquinone anti-neoplastic agents
Discrete element modelling of scaled railway ballast under triaxial conditions
The aim of this study is to demonstrate the use of tetrahedral clumps to model scaled railway ballast using the discrete element method (DEM). In experimental triaxial tests, the peak friction angles for scaled ballast are less sensitive to the confining pressure when compared to full-sized ballast. This is presumed to be due to the size effect on particle strength, whereby smaller particles are statistically stronger and exhibit less abrasion. To investigate this in DEM, the ballast is modelled using clumps with breakable asperities to produce the correct volumetric deformation. The effects of the quantity and properties of these asperities are investigated, and it is shown that the strength affects the macroscopic shear strength at both high and low confining pressures, while the effects of the number of asperities diminishes with increasing confining pressure due to asperity breakage. It is also shown that changing the number of asperities only affects the peak friction angle but not the ultimate friction angle by comparing the angles of repose of samples with different numbers of asperities
Influence of Method of Residue Application and Moisture Content on Water Soluble Nitrogen in a RhodicKandiustalf Amended with Different Fallow Plant Materials
Use of plant residues as nutrient sources presents a viable option to resource poor farmers who sparsely use mineral fertilizer in crop production. A study was conducted to gain an insight into how different application methods of residues from different fallow management systems under two moisture regimes would affect soluble N release in a Rhodic Kandiustalf. Three residue types viz, elephant grass from a natural fallow (T1) and another as a fallow following a previously fertilized maize (T2) and a fallow legume (T3) were surface applied and incorporated in a Rhodic Kandiustalf at both field capacity (FC) and 60% field capacity over a sixteen-week period. Incorporation of mucuna residues and elephant grass from previously fertilized maize fallow released similar soluble N levels which were higher than levels from the natural elephant grass amendments. At 60% FC, both mucuna and elephant grass from the fertilized maize fields that were surface applied had slower N releases than the grass from the natural fallow, suggesting the elephant grass from the natural fallow field could be used as an N source amidst light watering to avoid leaching in the dry season
Stakeholders' role in improving Ghana's construction safety
Health and safety (H&S) management has traditionally been the responsibility of the contractor. Most often, contractors are blamed for the accidents and other ill health that occur on their construction sites. H&S performance is, however, enhanced when there is effective collaboration between those involved in the construction process. This paper therefore explores the role of stakeholders in promoting construction H&S in Ghana through public works procurement. The four main stakeholders identified and evaluated in this study are the government, the client (employer), the contractor and the employee(s). Seven interviewees (comprising procurement managers, consultants and quantity surveyors) from public institutions in Ghana participated in the research. Data were collected using semi-structured interviews and were thematically analysed. Results indicate a conflict in the perceived functions and relation of these stakeholders in the construction process. To address the constraint to improving construction H&S, certain recommendations are offered. These include the identification of specific individuals responsible for supervision and employee training, the development of H&S policies by the government and contracts that clearly outline the contractual obligations of all parties involved. Additionally, the specific roles and involvements of other stakeholders in the procurement process in improving construction H&S are also outlined
Count every newborn; a measurement improvement roadmap for coverage data.
BACKGROUND: The Every Newborn Action Plan (ENAP), launched in 2014, aims to end preventable newborn deaths and stillbirths, with national targets of ≤12 neonatal deaths per 1000 live births and ≤12 stillbirths per 1000 total births by 2030. This requires ambitious improvement of the data on care at birth and of small and sick newborns, particularly to track coverage, quality and equity. METHODS: In a multistage process, a matrix of 70 indicators were assessed by the Every Newborn steering group. Indicators were graded based on their availability and importance to ENAP, resulting in 10 core and 10 additional indicators. A consultation process was undertaken to assess the status of each ENAP core indicator definition, data availability and measurement feasibility. Coverage indicators for the specific ENAP treatment interventions were assigned task teams and given priority as they were identified as requiring the most technical work. Consultations were held throughout. RESULTS: ENAP published 10 core indicators plus 10 additional indicators. Three core impact indicators (neonatal mortality rate, maternal mortality ratio, stillbirth rate) are well defined, with future efforts needed to focus on improving data quantity and quality. Three core indicators on coverage of care for all mothers and newborns (intrapartum/skilled birth attendance, early postnatal care, essential newborn care) have defined contact points, but gaps exist in measuring content and quality of the interventions. Four core (antenatal corticosteroids, neonatal resuscitation, treatment of serious neonatal infections, kangaroo mother care) and one additional coverage indicator for newborns at risk or with complications (chlorhexidine cord cleansing) lack indicator definitions or data, especially for denominators (population in need). To address these gaps, feasible coverage indicator definitions are presented for validity testing. Measurable process indicators to help monitor health service readiness are also presented. A major measurement gap exists to monitor care of small and sick babies, yet signal functions could be tracked similarly to emergency obstetric care. CONCLUSIONS: The ENAP Measurement Improvement Roadmap (2015-2020) outlines tools to be developed (e.g., improved birth and death registration, audit, and minimum perinatal dataset) and actions to test, validate and institutionalise proposed coverage indicators. The roadmap presents a unique opportunity to strengthen routine health information systems, crosslinking these data with civil registration and vital statistics and population-based surveys. Real measurement change requires intentional transfer of leadership to countries with the greatest disease burden and will be achieved by working with centres of excellence and existing networks
Tillage methods related to soil and water conservation in south Asia
Research on different tillage systems and their role in soil and water conservation in south Asia is reviewed. Tillage has shown marked influence on soil hydraulic characteristics and to some extent on soil chemical and biological properties particularly organic matter cycling. The importance of conservation tillage in reducing runoff, soil loss and in ensuring sustainable agricultural production in the region is emphasized. The role of other tillage practices, for example contour cultivation, contour bunding, terraces and tied ridging, in increasing the profile water storage is discusse
Gaseous emissions during concurrent combustion of biomass and non-recyclable municipal solid waste
Background: Biomass and municipal solid waste offer sustainable sources of
energy; for example to meet heat and electricity demand in the form of combined
cooling, heat and power. Combustion of biomass has a lesser impact than solid
fossil fuels (e. g. coal) upon gas pollutant emissions, whilst energy recovery
from municipal solid waste is a beneficial component of an integrated,
sustainable waste management programme. Concurrent combustion of these fuels
using a fluidised bed combustor may be a successful method of overcoming some of
the disadvantages of biomass (high fuel supply and distribution costs,
combustion characteristics) and characteristics of municipal solid waste
(heterogeneous content, conflict with materials recycling). It should be
considered that combustion of municipal solid waste may be a financially
attractive disposal route if a 'gate fee' value exists for accepting waste for
combustion, which will reduce the net cost of utilising relatively more
expensive biomass fuels. Results: Emissions of nitrogen monoxide and sulphur
dioxide for combustion of biomass are suppressed after substitution of biomass
for municipal solid waste materials as the input fuel mixture. Interactions
between these and other pollutants such as hydrogen chloride, nitrous oxide and
carbon monoxide indicate complex, competing reactions occur between
intermediates of these compounds to determine final resultant emissions.
Conclusions: Fluidised bed concurrent combustion is an appropriate technique to
exploit biomass and municipal solid waste resources, without the use of fossil
fuels. The addition of municipal solid waste to biomass combustion has the
effect of reducing emissions of some gaseous pollutants
Global, regional, and national comparative risk assessment of 84 behavioural, environmental and occupational, and metabolic risks or clusters of risks for 195 countries and territories, 1990–2017 : a systematic analysis for the Global Burden of Disease Study 2017
Background: The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2017 comparative risk assessment (CRA) is a comprehensive approach to risk factor quantification that offers a useful tool for synthesising evidence on risks and risk outcome associations. With each annual GBD study, we update the GBD CRA to incorporate improved methods, new risks and risk outcome pairs, and new data on risk exposure levels and risk outcome associations.
Methods: We used the CRA framework developed for previous iterations of GBD to estimate levels and trends in exposure, attributable deaths, and attributable disability-adjusted life-years (DALYs), by age group, sex, year, and location for 84 behavioural, environmental and occupational, and metabolic risks or groups of risks from 1990 to 2017. This study included 476 risk outcome pairs that met the GBD study criteria for convincing or probable evidence of causation. We extracted relative risk and exposure estimates from 46 749 randomised controlled trials, cohort studies, household surveys, census data, satellite data, and other sources. We used statistical models to pool data, adjust for bias, and incorporate covariates. Using the counterfactual scenario of theoretical minimum risk exposure level (TMREL), we estimated the portion of deaths and DALYs that could be attributed to a given risk. We explored the relationship between development and risk exposure by modelling the relationship between the Socio-demographic Index (SDI) and risk-weighted exposure prevalence and estimated expected levels of exposure and risk-attributable burden by SDI. Finally, we explored temporal changes in risk-attributable DALYs by decomposing those changes into six main component drivers of change as follows: (1) population growth; (2) changes in population age structures; (3) changes in exposure to environmental and occupational risks; (4) changes in exposure to behavioural risks; (5) changes in exposure to metabolic risks; and (6) changes due to all other factors, approximated as the risk-deleted death and DALY rates, where the risk-deleted rate is the rate that would be observed had we reduced the exposure levels to the TMREL for all risk factors included in GBD 2017.
Findings: In 2017,34.1 million (95% uncertainty interval [UI] 33.3-35.0) deaths and 121 billion (144-1.28) DALYs were attributable to GBD risk factors. Globally, 61.0% (59.6-62.4) of deaths and 48.3% (46.3-50.2) of DALYs were attributed to the GBD 2017 risk factors. When ranked by risk-attributable DALYs, high systolic blood pressure (SBP) was the leading risk factor, accounting for 10.4 million (9.39-11.5) deaths and 218 million (198-237) DALYs, followed by smoking (7.10 million [6.83-7.37] deaths and 182 million [173-193] DALYs), high fasting plasma glucose (6.53 million [5.23-8.23] deaths and 171 million [144-201] DALYs), high body-mass index (BMI; 4.72 million [2.99-6.70] deaths and 148 million [98.6-202] DALYs), and short gestation for birthweight (1.43 million [1.36-1.51] deaths and 139 million [131-147] DALYs). In total, risk-attributable DALYs declined by 4.9% (3.3-6.5) between 2007 and 2017. In the absence of demographic changes (ie, population growth and ageing), changes in risk exposure and risk-deleted DALYs would have led to a 23.5% decline in DALYs during that period. Conversely, in the absence of changes in risk exposure and risk-deleted DALYs, demographic changes would have led to an 18.6% increase in DALYs during that period. The ratios of observed risk exposure levels to exposure levels expected based on SDI (O/E ratios) increased globally for unsafe drinking water and household air pollution between 1990 and 2017. This result suggests that development is occurring more rapidly than are changes in the underlying risk structure in a population. Conversely, nearly universal declines in O/E ratios for smoking and alcohol use indicate that, for a given SDI, exposure to these risks is declining. In 2017, the leading Level 4 risk factor for age-standardised DALY rates was high SBP in four super-regions: central Europe, eastern Europe, and central Asia; north Africa and Middle East; south Asia; and southeast Asia, east Asia, and Oceania. The leading risk factor in the high-income super-region was smoking, in Latin America and Caribbean was high BMI, and in sub-Saharan Africa was unsafe sex. O/E ratios for unsafe sex in sub-Saharan Africa were notably high, and those for alcohol use in north Africa and the Middle East were notably low.
Interpretation: By quantifying levels and trends in exposures to risk factors and the resulting disease burden, this assessment offers insight into where past policy and programme efforts might have been successful and highlights current priorities for public health action. Decreases in behavioural, environmental, and occupational risks have largely offset the effects of population growth and ageing, in relation to trends in absolute burden. Conversely, the combination of increasing metabolic risks and population ageing will probably continue to drive the increasing trends in non-communicable diseases at the global level, which presents both a public health challenge and opportunity. We see considerable spatiotemporal heterogeneity in levels of risk exposure and risk-attributable burden. Although levels of development underlie some of this heterogeneity, O/E ratios show risks for which countries are overperforming or underperforming relative to their level of development. As such, these ratios provide a benchmarking tool to help to focus local decision making. Our findings reinforce the importance of both risk exposure monitoring and epidemiological research to assess causal connections between risks and health outcomes, and they highlight the usefulness of the GBD study in synthesising data to draw comprehensive and robust conclusions that help to inform good policy and strategic health planning
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