Lower urinary tract dysfunction in children with chronic kidney disease: before an after renal transplantation

Chronic kidney disease (CKD) in children is a complex condition with the risk of progression to end-stage renal disease (ESRD) requiring dialysis or renal transplantation. Children with CKD and pediatric renal transplant recipients face a variety of complications, such as side effects of the treatment and concerns about deterioration of graft function. Urinary tract infections (UTIs) are common complications that may harm renal function. In the general population lower urinary tract (LUT) dysfunction is a major risk factor for UTI, but less is known about LUT dysfunction in children with CKD or a renal transplant. The overall aim of this thesis was to evaluate LUT function in children with CKD before and after renal transplantation, and to study the role of LUT dysfunction in relation to UTIs. An additional aim was to gain knowledge about associations between LUT dysfunction and health related quality of life (HRQoL) in children with CKD before and after transplantation. All studies were cross-sectional and included 40 children with CKD stages 3–5 (Studies III and IV), 68 children with a renal transplant (Studies I and II), and 59 children (Study V) with CKD stage 3–5 (n=23), or with a renal transplant (n=36). The documents and investigations used to evaluate LUT function were bladder diaries/questionnaires, uroflowmetry, bladder ultrasound (for measuring post-void residual urine), and, in Study IV, cystometry. The glomerular filtration rate (GFR) was assessed by the renal clearance of inulin or iohexol, or estimated by the plasma level of cystatin C. The history of UTI was obtained by reviewing the medical records. Two questionnaires, the Kidscreen-27 and Disabkids-37, were used for self-ratings of HRQoL and the modified Symptom Inventory for assessing associated subjective symptoms (Study V). One or more signs of LUT dysfunction were found in 72.5% of children with CKD and in 72% of those with a renal transplant. Signs of LUT dysfunction were observed in all (100%) of the children with CKD along with underlying urological disorders and in 59% with non-urological disorders (p = 0.0074). Regarding LUT function in children with a renal transplant, no significant difference was found in groups with and without urinary tract malformations (74% vs. 71%, NS). In children with CKD, 47.5% had a bladder capacity larger than expected and the large bladder was often combined with reduced bladder sensation. A discontinuous urinary flow was found in 20% and 15% had residual urine. Corresponding figures in children with a renal transplant were 26%, 50% (17.6%, with a tower pattern excluded), and 32%. UTIs were more common in children with CKD and signs of LUT dysfunction than in those without (55% vs. 0%, p = 0.0012). In children with a renal transplant, recurrent UTIs were equally common in children with and without LUT dysfunction (35% vs. 42%, NS). Recurrent UTIs were, however, associated with a faster deterioration of GFR than in those without UTIs (p = 0.02). Children with CKD or a renal transplant with or without signs of LUT dysfunction reported a similar HRQoL, except those with incontinence, who reported lower HRQoL. Girls and older children rated well-being lower, as did those with a renal transplant. The entire study population perceived poorer well-being than healthy children, but similar to those with chronic conditions other than CKD. In conclusion, LUT dysfunction is common in children with CKD stages 3–5 and pediatric renal transplant recipients, not only in children with urological disorders but also in those with non- urological disorders. Earlier UTIs and LUT dysfunction seem to correlate in children before, but not after a renal transplantation. The findings in this thesis contribute to our knowledge about LUT dysfunction in children with CKD stage 3–5 and pediatric renal transplant recipients, but also to our knowledge about the association between HRQoL and LUT dysfunction as well as possible impact of CKD status, sex and age. Further research is needed before general recommendations for possible interventions can be given

Agroforestry's contribution to livelihoods and carbon sequestration in East Africa: A systematic review

Agroforestry is a powerful practice for sustainable and regenerative intensification because it promotes multifunctional landscapes that deliver ecological functions that contribute to livelihoods, land productivity, biodiversity conservation, and other ecosystem services. Despite a large body of literature on agroforestry in East Africa, a systematic understanding of its livelihood benefits and contribution to carbon sequestration is still lacking. A systematic review was used to provide a quantitative and qualitative synthesis of available evidence and knowledge gap from 185 publications that met the selection criteria regarding the contribution of agroforestry to livelihoods (n = 152) and carbon sequestration (n = 43) in East Africa. The main livelihood benefits include fodder, food, firewood and income, reported in over 70, 63, 56 and 40 publications, respectively. These and other benefits diversify livelihoods of rural communities and act as safety nets in times of climate shocks. Agroforestry systems in East Africa stock an average of 24.2 +/- 2.8 Mg C ha-1 in biomass and 98.8 +/- 12.2 Mg C ha-1 in the soil. Much of the aboveground carbon is held in homegardens (34.3 +/- 7.9 Mg C ha-1), perennial treecrop systems (29.9 +/- 12.7 Mg C ha-1) and trees on boundaries (26.7 +/- 14.1 Mg C ha-1). Empirical studies are needed for better understanding of belowground carbon in agroforestry and emission of greenhouse gases in different agroforestry practices. A smaller number of studies reported income from sale of carbon credits, suggesting a gap in the development of science regarding carbon rights, land tenure, tree tenure rights, and the potential impact of climate change on the growing niches of tree species in the region. The results show that agroforestry is a powerful climate adaptation and mitigation solution as it can increase household resilience and sequesters significant amounts of carbon dioxide from the atmosphere

Climate change awareness and adaptation strategies by smallholder farmers in semi-arid areas of Zimbabwe

Agricultural production, food, nutrition and income security of smallholder farmers in sub-Saharan Africa are threatened by extreme weather events, such as increased frequency of mid-season dry spells and increased temperatures. Their impacts are exacerbated by the prevalence of sandy soils, characterized by limited water and nutrient retention capacity leading to low crop productivity. In this study, we aimed at assessing farmers' awareness of extreme weather events, identify adaptation strategies and evaluate maize yield from different soil fertility and water management practices. A household survey including 245 smallholder farmers in Marange, Zimbabwe was carried out. The results revealed that farmers were aware of and had experienced extreme weather events. Among adaptation strategies used were soil water-harvesting, use of improved varieties, mulching and planting trees. Maize yield remains significantly low, averaging 0.62 t ha-1 among farmers using some forms of soil fertility and water management strategies. To further understand the reason for low maize yields and improve climate change related adaptation strategies, more research is needed to quantify and confirm management practices applied by farmers, such as fertilizer use and rates, water and nutrient management, use of improved varieties as well as socio-economic factors

Waste recovered by-products can increase growth of grass-clover mixtures in low fertility soils and alter botanical and mineral nutrient composition

The effectiveness of four by-products (biogas digestate, pot ale, rockdust and wood ash) as fertilisers of a perennial ryegrass (Lolium perenne)-red clover (Trifolium pratense) mixture in terms of biomass production, botanical composition and macro- and micronutrient concentrations was tested in an outdoor pot trial. This was carried out over two growing seasons using two inherently low-fertility soils used for forage production. Macro- and micronutrients (N, P, K, Ca, Mg, Co, Cu, Mn, Mo and Zn) relevant for crops and livestock were determined in soils and plants. All the by-products increased overall biomass production and affected nutrient concentrations of the individual plant species to varying degrees. In addition the competitive balance between grass and clover was altered leading to different botanical composition in the different treatments and consequently differences in the nutrient concentrations of the species mixture. Changes were due to the nutrients applied in the by-products per se and/or to changes in the soil chemistry caused by the by-products. The results suggest a potential to enhance agricultural productivity through improved production and quality of forage on less fertile land by matching of by-products and soil properties

Effect of short-term perennial leys on life cycle environmental performance of cropping systems: An assessment based on data from a long-term field experiment

Modern agriculture's dependence on the intensive use of inputs, such as chemical fertiliser and pesticides, leads to high environmental impacts and, possibly, vulnerability in food security, since most of these inputs are im-ported from other countries. This calls for more sustainable and resilient agricultural practices. Diversification of crop rotations, e.g. by including perennial leys, enhances provision of ecosystem services, leading to healthier crops and increased yields. Perennial crops also increase soil organic carbon (SOC) stocks, which is interesting from a global warming mitigation perspective. In addition, legume-rich leys can utilise atmospheric nitrogen (N) through symbiotic association with N2-fixing bacteria. However, few studies have evaluated the effects of short-term perennial leys in rotation on cropping system performance over long periods and under different conditions. In this study, we used data from three sites in a long-term experiment in Sweden (initiated in the 1960 s), in combination with Life Cycle Assessment methodology, to assess the environmental and yield effect of including ley in crop rotations. Two N fertiliser regimes (High, Low) in combination with three six-year crop rotations, consisting of either i) two-year mixed grass-legume ley, ii) two-year pure grass ley or iii) annual crops without ley, were compared. Environmental impacts (climate impact, energy resource depletion, eutrophication poten-tial) of the different combinations were quantified per kg harvested crop (expressed in cereal units, CU) and per hectare. The lowest environmental impact, at all sites, was found for the crop rotation with two-year mixed ley under the Low N regime. On average, this combination resulted in 329 g lower GHG emissions per kg CU than the crop rotation without ley and Low N, primarily due to lower input of chemical N fertiliser, which reduced the impact from fertiliser production and soil N2O emissions. Comparison of mean SOC change over the study period revealed reduced SOC stocks for all rotations and all sites, especially in the rotation without ley. Therefore, including short-term perennial leys, especially leys containing legume species, in crop rotations can be a useful tool in meeting policy targets on reducing the environmental impacts of agriculture, and in reducing the dependence on purchased agricultural commodities. However, despite the potential benefits of rotational leys, the market demand for the produced ley biomass may be insufficient. Hence, incentives to increase demand are necessary to promote large-scale adoption, for example, for use in bioenergy production and feed

Appraisal of world reference base for soil resources - from a nordic point of view

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