As the importance of fecal sludge management (FSM) is increasingly being realized, the need for adequately designed and functioning fecal sludge (FS) treatment plants is also increasing. Research to fill this gap is only emerging and dewatering is a key challenge for developing sustainable treatment solutions. This study evaluated the effect of extracellular polymeric substances (EPS) on dewaterability of FS, and how EPS and dewaterability change during anaerobic storage (as a proxy for time in onsite containment).
View Article and Find Full Text PDFThe characteristics of fecal sludge delivered to treatment plants are highly variable. Adapting treatment process operations accordingly is challenging due to a lack of analytical capacity for characterization and monitoring at many treatment plants. Cost-efficient and simple field measurements such as photographs and probe readings could be proxies for process control parameters that normally require laboratory analysis.
View Article and Find Full Text PDFFaecal sludge dewatering is often a necessary step in many treatment and reuse processes, and it can decrease costs of transporting large volumes of high water content sludge. Common dewatering methods such as settling-thickening tanks and drying beds are not feasible in space-constrained areas such as urban informal settlements, therefore innovative dewatering methods are needed. This study evaluated permeable membranes as a dewatering method for a transfer station operated by Sanergy in Nairobi, Kenya.
View Article and Find Full Text PDFUnpredictable dewatering performance is a barrier to the effective management and treatment of faecal sludge. While mechanisms of dewatering in sludges from wastewater treatment are well understood, it is not clear how dewatering of faecal sludge fits into the framework of existing knowledge. We evaluate physical-chemical parameters, including EPS and cations, and demographic (source), environmental (microbial community), and technical factors (residence time) as possible predictors of dewatering performance in faecal sludge, and make comparisons to the existing conceptual model for wastewater sludge.
View Article and Find Full Text PDFIn many low-income cities, a high proportion of fecal sludge, the excreta and blackwater collected from onsite sanitation systems such as pit latrines, is not safely managed. This constitutes a major danger to environmental and human health. The water, sanitation, and hygiene sector has recognized that valorization of treated fecal sludge could offset the upfront cost of treatment by using it as a fuel source.
View Article and Find Full Text PDFSanitation access in urban areas of low-income countries is provided through unstandardized onsite technologies containing accumulated faecal sludge. The demand for infrastructure to manage faecal sludge is increasing, however, no reliable method exists to estimate total accumulated quantities and qualities (Q&Q) This proposed approach averages out complexities to estimate conditions at a centralized to semi-centralized scale required for management and treatment technology solutions, as opposed to previous approaches evaluating what happens in individual containments. Empirical data, demographic data, and questionnaires were used in Kampala, Uganda to estimate total faecal sludge accumulation in the city, resulting in 270 L/cap∙year for pit latrines and 280 L/cap∙year for septic tanks.
View Article and Find Full Text PDFInvestigations involving human faeces and faecal sludge are of great importance for urban sanitation, such as operation and maintenance of sewer systems, or implementation of faecal sludge management. However, working with real faecal matter is difficult as it not only involves working with a pathogenic, malodorous material but also individual faeces and faecal sludge samples are highly variable, making it difficult to execute repeatable experiments. Synthetic faeces and faecal sludge can provide consistently reproducible substrate and alleviate these challenges.
View Article and Find Full Text PDFThe developing world faces dual crises of escalating energy demand and lack of urban sanitation infrastructure that pose significant burdens on the environment. This article presents results of a study evaluating the feasibility of using human feces-derived char as a solid fuel for heating and cooking and a potential way to address both crises. The study determined the energy content and the elemental composition of chars pyrolyzed at 300, 450, and 750 °C.
View Article and Find Full Text PDFBackground: We conducted a population-based human exposure study in response to concerns among the population of Midland and Saginaw counties, Michigan, that discharges by the Dow Chemical Company of dioxin-like compounds into the nearby river and air had led to an increase in residents' body burdens of polychlorinated dibenzofurans (PCDDs), polychlorinated dibenzofurans (PCDFs), and dioxin-like polychlorinated biphenyls (PCBs), here collectively referred to as "dioxins."
Objectives: We sought to identify factors that explained variation in serum dioxin concentrations among the residents of Midland and Saginaw counties. Exposures to dioxins in soil, river sediments, household dust, historic emissions, and contaminated fish and game were of primary interest.
Background: The University of Michigan Dioxin Exposure Study was undertaken to address concerns that the discharge of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzo furans (PCDFs) from the Dow Chemical Company in the Midland, Michigan, area had resulted in contamination of soils in the Tittabawassee River floodplain and the city of Midland, leading to an increase in residents' body burdens of these compounds.
Objective: In this article we present descriptive statistics from the resident survey and sampling of human serum, household dust, and soil and compare them with other published values.
Methods: From a multistage random sample of populations in four areas of Midland and Saginaw counties and from a distant referent population, we interviewed 946 adults, who also donated blood for analysis of PCDDs, PCDFs, and polychlorinated biphenyls (PCBs).
Background: The University of Michigan Dioxin Exposure Study (UMDES) was undertaken in response to concerns that the discharge of dioxin-like compounds from the Dow Chemical Company facilities in Midland, Michigan, resulted in contamination of soils in the Tittabawassee River floodplain and areas of the city of Midland, leading to an increase in residents' body burdens of polychlorinated dibenzodioxins and polychlorinated dibenzofurans.
Objectives: The UMDES is a hypothesis-driven study designed to answer important questions about human exposure to dioxins in the environment of Midland, where the Dow Chemical Company has operated for > 100 years, and in neighboring Saginaw, Michigan. In addition, the UMDES includes a referent population from an area of Michigan in which there are no unusual sources of dioxin exposure and from which inferences regarding the general Michigan population can be derived.
Objective: We previously showed that ischemia, induced by interrupting vascular flow, reduced cardiac capillary caliber. This was accomplished by a reduction in endothelial cell dimensions which was sensitive to Rho kinase (ROK) inhibition and stabilization of the actin cytoskeleton. Here, we investigated whether similar changes in endothelial cells, in situ, could be elicited in the presence of flow through the capillary bed.
View Article and Find Full Text PDFUnlabelled: The utility of breast magnetic resonance imaging in patients receiving neoadjuvant chemotherapy is not well defined. We compared serial magnetic resonance imaging examinations with histologic posttreatment examinations in patients treated with primary chemotherapy for locally advanced breast cancer.
Patients And Methods: Eligible patients with locally advanced breast cancer received doxorubicin 60 mg/m(2) and docetaxel 60 mg/m(2) (with granulocyte colony stimulating factor support) every 14 days for a maximum of six cycles.
Historical data suggested that a soluble protein, since identified as annexin-A1 (Anx-A1) was released from macrophages following glucocorticoid stimulation and could modulate eicosanoid production and other functions of these cells. Here, we review some recent findings using a line of Anx-A1(-/-) mice to explore the impact of Anx-A1 gene deletion on macrophage biology. The absence of Anx-A1 selectively alters phagocytic capacity of rodent resident peritoneal macrophages apparently through changes in surface adhesion molecule expression.
View Article and Find Full Text PDFRecent research has suggested that an increased (n-3) fatty acid intake and/or increased (n-3)/(n-6) polyunsaturated fatty acid (PUFA) ratio in the diet is associated with a lower breast cancer risk. This case-control study investigated the association between intake of (n-3) and other fatty acids and the (n-3)/(n-6) PUFA ratio and breast cancer risk. After combining data from two related case-control studies in Connecticut, we had information available on a total of 1119 women (565 cases and 554 controls).
View Article and Find Full Text PDFThe Ca(2+)- and phospholipid-binding protein Anx-A1 (annexin 1; lipocortin 1) has been described both as an inhibitor of phospholipase A(2) (PLA(2)) activity and as a mediator of glucocorticoid-regulated cell growth and eicosanoid generation. Here we show that, when compared with Anx-A1(+/+) cells, lung fibroblast cell lines derived from the Anx-A1(-/-) mouse exhibit an altered morphology characterized by a spindle-shaped appearance and an accumulation of intracellular organelles. Unlike their wild-type counterparts, Anx-A1(-/-) cells also overexpress cyclo-oxygenase 2 (COX 2), cytosolic PLA(2) and secretory PLA(2) and in response to fetal calf serum, exhibit an exaggerated release of eicosanoids, which is insensitive to dexamethasone (10(-8)- 10(-6) M) inhibition.
View Article and Find Full Text PDFObjective: We have previously demonstrated that ischaemia and reperfusion of the myocardium alter capillary dimensions and endothelial cell shape and that these changes are likely to be effected by the actomyosin contractile system in endothelial cells. Rho GTPases are involved in the regulation of cytoskeletal re-organization and in cell contraction. Rho-associated kinase regulates the sensitivity of myosin light chain to Ca(2+) in smooth muscle but not in cardiac or skeletal muscle myocytes.
View Article and Find Full Text PDFReperfusion of the ischemic myocardium results in structural changes in the capillary bed, which may contribute to decreased microcirculatory flow ("no reflow"). This study was designed to correlate the endothelial cell shape changes with both oxidative stress and lipid peroxidation and to evaluate the beneficial potential of Trolox (a hydrophilic analogue of alpha-tocopherol) and ascorbic acid. Isolated buffer-perfused rat hearts were made ischemic for 45 min and then reperfused with 100 microM Trolox and/or 100 microM ascorbic acid.
View Article and Find Full Text PDFThe recovery of any tissue following a period of ischaemia is dependent on a patent microvasculature to restore blood flow. In the ischaemic myocardium, a reduction in capillary cross-sectional dimensions occurs, which is likely to contribute to "no-reflow" injury. Clinical and experimental evidence indicates that the retina is able to tolerate moderate periods of ischaemia without significant loss of function.
View Article and Find Full Text PDFBackground: Management of early-stage breast cancer in young women with mutations in BRCA1 or BRCA2 remains controversial. This study assessed the long-term risks of ipsilateral and contralateral breast cancer in a cohort of young women who underwent breast-conserving surgery followed by radiotherapy.
Methods: Between 1975 and 1998, 290 women with breast cancer diagnosed at age 42 years or younger underwent lumpectomy followed by radiotherapy at our hospital.
A reduction in capillary dimensions has been demonstrated in postischaemic reperfusion in the heart. The aim of this study was to demonstrate that in ischaemia and ischaemia followed by reperfusion, the change in shape of the constituent endothelial cells can be inhibited by phalloidin which stabilises the actin microfilament system. Isolated, perfused rat hearts were made globally ischaemic both with and without reperfusion and in the presence or absence of phalloidin.
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