Modelling sediment supply and transport in the River Lugg: strategies for controlling sediment loads

The River Lugg has particular problems with high sediment loads that have resulted in detrimental impacts on ecology and fisheries. A new dynamic, process-based model of hydrology and sediments (INCA- SED) has been developed and applied to the River Lugg system using an extensive data set from 1995–2008. The model simulates sediment sources and sinks throughout the catchment and gives a good representation of the sediment response at 22 reaches along the River Lugg. A key question considered in using the model is the management of sediment sources so that concentrations and bed loads can be reduced in the river system. Altogether, five sediment management scenarios were selected for testing on the River Lugg, including land use change, contour tillage, hedging and buffer strips. Running the model with parameters altered to simulate these five scenarios produced some interesting results. All scenarios achieved some reduction in sediment levels, with the 40% land use change achieving the best result with a 19% reduction. The other scenarios also achieved significant reductions of between 7% and 9%. Buffer strips produce the best result at close to 9%. The results suggest that if hedge introduction, contour tillage and buffer strips were all applied, sediment reductions would total 24%, considerably improving the current sediment situation. We present a novel cost-effectiveness analysis of our results where we use percentage of land removed from production as our cost function. Given the minimal loss of land associated with contour tillage, hedges and buffer strips, we suggest that these management practices are the most cost-effective combination to reduce sediment loads

Modelling fixed plant and algal dynamics in rivers

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Delta Dynamic Integrated Emulator Model

The aim of the ESPA Deltas project was to provide policy makers with the knowledge and tools to enable them to evaluate the effects of policy decisions on ecosystem services and people&#39;s livelihoods. In another word, to link science to policy at the landscape scale. ESPA Deltas investigated the south-west coastal zone of Bangladesh through a transdisciplinary lens. The Delta Dynamic Integrated Emulator Model (&Delta;DIEM) is essentially a trans-disciplinary framework designed to analyse linkages between ecosystem services, livelihoods, well-being and governance in coastal Bangladesh. It is designed to support the delta planning in Bangladesh. It is a tightly coupled platform driven by climatic and environmental change, demographic changes, economic changes, household decisions and governance and estimating the resulting wellbeing and poverty of the coastal population. &Delta;DIEM has built-in water-based structural and policy interventions (e.g. embankment changes, new crops, subsidies, loan structures, etc.) that enables consistent model runs within a robust scenario framework. Thus, development trajectories and their trade-offs can be quantified.</span

Leptin gene (TTTC)n microsatellite polymorphism in pre-eclampsia and HELLP syndrome

Background: Leptin plays an important role in energy homeostasis. There is polymorphism on the leptin (LEP) gene. Our aim was to compare the tetranucleotide repeat (TTTC)n polymorphism in the 3′-flanking region in the LEP gene on DNA samples from patients with pre-eclampsia (PE), hemolysis, elevated liver enzymes, and low platelet (HELLP) syndrome and healthy pregnant controls. Methods: Blood samples were collected from healthy pregnant women (n=88), patients with PE (n=79) and HELLP (n=77) syndrome. Fluorescent PCR and DNA fragment analysis was performed from the isolated DNA for the detection of (TTTC) repeats. The electrophoretograms were evaluated and patients were assigned to two groups; class I low (&#60;190 bp) or class II high (≥190 bp) PCR fragments. Results: We observed similar distributions of the class I and class II (TTTC) alleles in the groups studied (class I allele: healthy pregnant 58.5%; severe pre-eclamptic 58.3%; HELLP syndrome 52.6%). We detected a higher frequency of the II/II genotype in HELLP syndrome patients (32.4%) compared to healthy controls (22.7%). However, the difference was not statistically significant. Conclusions: In an ethnically homogenous population, the LEP gene (TTTC) microsatellite polymorphism in the 3′-flanking region does not show a significant difference in the allele and genotype distribution in healthy pregnant, pre-eclamptic and HELLP syndrome patients. Furthermore, we recommend a new classification of the class I and class II alleles based on the distribution of the (TTTC) microsatellites. Clin Chem Lab Med 2009;47:1033–7.Peer Reviewe

Leptin gene (TTTC)n microsatellite polymorphism in pre-eclampsia and HELLP syndrome

Background: Leptin plays an important role in energyhomeostasis. There is polymorphism on the leptin(LEP) gene. Our aim was to compare the tetranucleo-tide repeat (TTTC)npolymorphism in the 39-flankingregion in theLEPgene on DNA samples from patientswith pre-eclampsia (PE), hemolysis, elevated liverenzymes, and low platelet (HELLP) syndrome andhealthy pregnant controls.Methods: Blood samples were collected from healthypregnant women (ns88), patients with PE (ns79) andHELLP (ns77) syndrome. Fluorescent PCR and DNAfragment analysis was performed from the isolatedDNA for the detection of (TTTC) repeats. The electro-phoretograms were evaluated and patients wereassigned to two groups; class I low (-190 bp) or classII high (G190 bp) PCR fragments.Results: We observed similar distributions of the classI and class II (TTTC) alleles in the groups studied(class I allele: healthy pregnant 58.5%; severe pre-eclamptic 58.3%; HELLP syndrome 52.6%). We detect-ed a higher frequency of the II/II genotype in HELLPsyndrome patients (32.4%) compared to healthy con-trols (22.7%). However, the difference was not statis-tically significant.Conclusions: In an ethnically homogenous popula-tion, the LEP gene (TTTC) microsatellite polymor-phism in the 3 9 -flanking region does not show asignificant difference in the allele and genotype dis-tribution in healthy pregnant, pre-eclamptic andHELLP syndrome patients. Furthermore, we recom-mend a new classification of the class I and class II alleles based on the distribution of the (TTTC) microsatellites