Chapter 7: Wetlands

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Oral health status of 12-year-old school children in Khartoum state, the Sudan; a school-based survey

<p>Abstract</p> <p>Background</p> <p>Few studies have investigated the prevalence of dental caries among school children in the past decades in Sudan rendering it difficult to understand the status and pattern of oral health.</p> <p>Methods</p> <p>A school-based survey was conducted using stratified random cluster sampling in Khartoum state, Sudan. Data was collected through interviews and clinical examination by a single examiner. DMFT was measured according to WHO criteria. Gingival index (GI) of Loe & Silness and Plaque index (PI) of Silness & Loe were used.</p> <p>Results</p> <p>The mean DMFT for 12-year-olds was found to be 0.42 with a significant caries index (SiC) of 1.4. Private school attendees had significantly higher DMFT (0.57) when compared to public school attendees (0.4). The untreated caries prevalence was 30.5%. In multivariate analysis caries experience (DMFT > 0) was found to be significantly and directly associated with socioeconomic status. The mean GI for the six index teeth was found to be 1.05 (CI 1.03 – 1.07) and the mean PI was 1.30 (CI 1.22 – 1.38).</p> <p>Conclusion</p> <p>The prevalence of caries was found to be low. The school children with the higher socioeconomic status formed the high risk group.</p

Comparative LCA technology improvement opportunities for a 1.5 MW wind turbine in the context of an offshore wind farm

Wind energy is playing an increasingly important role in the development of cleaner and more efficient energy technologies leading to projections in reliability and performance of future wind turbine designs. This paper presents life cycle assessment (LCA) results of design variations for a 1.5 MW wind turbine due to the potential for advances in technology to improve the performance of a 1.5 MW wind turbine. Five LCAs have been conducted for design variants of a 1.5 MW wind turbine. The objective is to evaluate potential environmental impacts per kilowatt hour of electricity generated for a 114 MW onshore wind farm. Results for the baseline turbine show that higher contributions to impacts were obtained in the categories Ozone Depletion Potential, Marine Aquatic Eco-toxicity Potential, Human Toxicity Potential and Terrestrial Eco-toxicity Potential compared to Technology Improvement Opportunities (TIOs) 1 to 4. Compared to the baseline turbine, TIO 1 showed increased impact contributions to Abiotic Depletion Potential, Acidification Potential, Eutrophication Potential, Global Warming Potential and Photochemical Ozone Creation Potential, and TIO 2 showed an increase in contributions to Abiotic Depletion Potential, Acidification Potential and Global Warming Potential. Additionally, lower contributions to all the environmental categories were observed for TIO 3 while increased contributions towards Abiotic Depletion Potential and Global Warming Potential were noted for TIO 4. A comparative LCA study of wind turbine design variations for a particular power rating has not been explored in the literature. This study presents new insight into the environmental implications related with projected wind turbine design advancements

Energy return on investment (EROI) of mini-hydro and solar PV systems designed for a mini-grid

With dramatic cost declines and performance improvements, both mini-hydropower and solar photovoltaics (PV) now serve as core options to meet the growing demand for electricity in underserved regions worldwide. We compare the net energy return on energy invested (EROI) of mini-hydropower and solar electricity using five existing mini-hydropower installations in northern Thailand with grid-connected solar PV simulations. Both assessments use a life cycle perspective to estimate the EROI. We find that distributed mini-grids with penetrations of solar PV up to 50% of annual generation can exceed the EROI of some fossil-based traditional centralized grid systems. The analysis will help planners and engineers optimize mini-grids for energy payback and utilize local resources in their design. The results suggest higher EROI ratios for mini-hydropower plants than solar PV, though mini-hydropower plants typically yield lower EROI ratios than their large-scale hydropower counterparts

Prevention of early childhood caries

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/97473/1/j.1600-0528.1988.tb02094.x.pd

Transposing lessons between different forms of consequential greenhouse gas accounting: lessons for consequential life cycle assessment, project-level accounting, and policy-level accounting

AbstractGreenhouse gas accounting has developed in a number of semi-isolated fields of practice and there appears to be considerable opportunity for transposing methodological innovations and lessons between these different fields. This research paper identifies three consequential forms of greenhouse gas accounting: consequential life cycle assessment; project-level accounting; and policy-level accounting. These methods are described in detail and then compared in order to identify the key methodological differences and the potential lessons that can be transposed between them. Analysis of the substantive methodological differences suggests that consequential life cycle assessment could be enhanced by adopting the same structure used in project and policy-level accounting, which provides a time-series of impacts, aggregate level analysis, and a transparent specification of the baseline and decision scenarios. There is a case for conceptualising a unified form of consequential time-series assessment, of which project, policy and product assessments would be sub-types

Seal or Varnish? A randomised controlled trial to determine the relative cost and effectiveness of pit and fissure sealant and fluoride varnish in preventing dental decay

Background Fissure sealant (FS) and fluoride varnish (FV) have been shown to be effective in preventing dental caries when tested against a no-treatment control. However, the relative clinical effectiveness and cost-effectiveness of these interventions is unknown. Objective To compare the clinical effectiveness and cost-effectiveness of FS and FV in preventing dental caries in first permanent molars (FPMs) in 6- and 7-year-olds and to determine their acceptability. Design A randomised controlled allocation-blinded clinical trial with two parallel arms. Setting A targeted population programme using mobile dental clinics (MDCs) in schools located in areas of high social and economic deprivation in South Wales. Participants In total, 1016 children were randomised, but one parent subsequently withdrew permission and so the analysis was based on 1015 children. The randomisation of participants was stratified by school and balanced for sex and primary dentition baseline caries levels using minimisation in a 1 : 1 ratio for treatments. A random component was added to the minimisation algorithm, such that it was not completely deterministic. Of the participants, 514 were randomised to receive FS and 502 were randomised to receive FV. Interventions Resin-based FS was applied to caries-free FPMs and maintained at 6-monthly intervals. FV was applied at baseline and at 6-month intervals over the course of 3 years. Main outcome measures The proportion of children developing caries into dentine (decayed, missing, filled teeth in permanent dentition, i.e. D4–6MFT) on any one of up to four treated FPMs after 36 months. The assessors were blinded to treatment allocation; however, the presence or absence of FS at assessment would obviously indicate the probable treatment received. Economic measures established the costs and budget impact of FS and FV and the relative cost-effectiveness of these technologies. Qualitative interviews determined the acceptability of the interventions. Results At 36 months, 835 (82%) children remained in the trial: 417 in the FS arm and 418 in the FV arm. The proportion of children who developed caries into dentine on a least one FPM was lower in the FV arm (73; 17.5%) than in the FS arm (82, 19.6%) [odds ratio (OR) 0.84, 95% confidence interval (CI) 0.59 to 1.21; p = 0.35] but the difference was not statistically significant. The results were similar when the numbers of newly decayed teeth (OR 0.86, 95% CI 0.60 to 1.22) and tooth surfaces (OR 0.85, 95% CI 0.59 to 1.21) were examined. Trial fidelity was high: 95% of participants received five or six of the six scheduled treatments. Between 74% and 93% of sealants (upper and lower teeth) were intact at 36 months. The costs of the two technologies showed a small but statistically significant difference; the mean cost to the NHS (including intervention costs) per child was £500 for FS, compared with £432 for FV, a difference of £68.13 (95% CI £5.63 to £130.63; p = 0.033) in favour of FV. The budget impact analysis suggests that there is a cost saving of £68.13 (95% CI £5.63 to £130.63; p = 0.033) per child treated if using FV compared with the application of FS over this time period. An acceptability score completed by the children immediately after treatment and subsequent interviews demonstrated that both interventions were acceptable to the children. No adverse effects were reported. Limitations There are no important limitations to this study. Conclusions In a community oral health programme utilising MDCs and targeted at children with high caries risk, the twice-yearly application of FV resulted in caries prevention that is not significantly different from that obtained by applying and maintaining FSs after 36 months. FV proved less expensive. Future work The clinical effectiveness and cost-effectiveness of FS and FV following the cessation of active intervention merits investigation

Iranske oppfatninger av verdensorden

Denne bacheloroppgaven analyserer den iranske grunnloven og offentlige uttalelser fra Ayatollah Ali Khamenei, med forskningsspørsmålet: «Hvilke oppfatninger om verdensorden er sentrale i Iran?» Analysens hovedfunn er en iransk oppfatning der den islamske verden er i en konstant konflikt med den ikke-islamske vesten. I denne kampen for islamsk ekspansjon har Iran tatt rollen som revolusjonens lederstat, og plikter å støtte den islamske kampen overalt på kloden. Det finnes også en oppfatning av den vestlige verden og USA som en moderne imperialistisk kraft, som både materielt og kulturelt forsøker å øve innflytelse på Iran, og utnytte og svekke den islamske republikken. Resultatet er en iransk forståelse av den rådende verdensordenen som en der den vestlige verden dominerer resten av kloden, heller enn som et felleskap av liberale, demokratiske og suverene stater som samarbeider til alles felles nytte. Jeg diskuterer også et tilsynelatende avvik mellom iransk ordensoppfatning og utenrikspolitisk handling, og benytter meg av et realismeperspektiv for å argumentere for at denne utenrikspolitiske linjen kan være rasjonell og i tråd med et langsiktig mål om å styrte den gjeldende verdensordenen