121 research outputs found

    The fate of endocrine disrupting chemicals during activated sludge treatment

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    A significant route for Endocrine disrupting chemicals (EDCs) such as natural and synthetic estrogens and nonylphenolics to enter the environment is via sewage treatment. Nanogram per litre levels of these compounds have been demonstrated to cause feminisation of aquatic organisms. The utilisation of treatments such as advanced oxidation and activated carbon could remove these compounds from effluent; however these technologies are expensive and energy intensive. Determining which operating parameters control the biodegradation of EDCs during activated sludge treatment, removal could be more sustainable. This study investigates which process parameters are responsible for controlling biodegradation of estrogens and nonylphenolics during activated sludge treatment. The role ammonia oxidising bacteria upon the breakdown of estrogens was also investigated. Field-based sampling campaigns were undertaken at three activated sludge plants and pilot-scale porous pot bioreactors were utilised to further examine the individual influences of loading, hydraulic retention time (HRT) and sludge retention time (SRT) upon EDC biodegradation.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

    Combined knockout of collecting duct endothelin A and B receptors causes hypertension and sodium retention

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    The collecting duct (CD) endothelin (ET) system regulates blood pressure (BP) and Na excretion. CD-specific knockout (KO) of ET-1 causes hypertension, CD-specific KO of the ETA receptor does not alter BP, while CD-specific KO of the ETB receptor increases BP to a lesser extent than CD ET-1 KO. These findings suggest a paracrine role for CD-derived ET-1; however, they do not exclude compensation for the loss of one ET receptor by the other. To examine this, mice with CD-specific KO of both ETA and ETB receptors were generated (CD ETA/B KO). CD ETA/B KO mice excreted less urinary Na than controls during acute or chronic Na loading. Urinary aldosterone excretion and plasma renin concentration were similar during Na intake and both fell comparably during Na loading. On a normal sodium diet, CD ETA/B KO mice had increased BP, which increased further with high salt intake. The degree of BP elevation during normal Na intake was similar to CD ET-1 KO mice and higher than CD ETB KO animals. During 1 wk of Na loading, CD ETA/B KO mice had higher BPs than CD ETB KO, while BP was less than CD ET-1 KOs until the latter days of Na loading. These studies suggest that 1) CD ETA/B deficiency causes salt-sensitive hypertension, 2) CD ETA/B KO-associated Na retention is associated with failure to suppress the renin-angiotensin-aldosterone system, and 3) CD ETA and ETB receptors exerts a combined hypotensive effect that exceeds that of either receptor alone

    The Optimized-String Dynamic Photovoltaic Array

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    This paper presents a novel system for producing the optimum power output from photovoltaic (PV) arrays using dynamic cell reconfiguration. The proposed approach is the first in the literature that creates strings using individual substrings that have been characterized and categorized ensuring maximum power extraction for a given irradiance profile. This optimized and decentralized PV architecture can produce significantly more power than a static equivalent (by an average of 22.6%) and also outperforms the sophisticated alternative known as an irradiance equalized dynamic photovoltaic array (IEq-DPVA) by an average of 13.7% for the relevant tests carried out. This paper identifies the hardware requirements to produce such a system and it describes an algorithm that performs the optimized-string reconfiguration strategy. Finally, a simulator programmed in MATLAB is used to compare the performance of the optimized-string DPVA against an IEq-DPVA in a series of flexibility tests

    The International Research Society of Spinal Deformities (IRSSD) and its contribution to science

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    From the time of its initial, informal meetings starting in 1980 to its formal creation in 1990, the IRSSD has met on a bi-annual basis to discuss all aspects of the spine and associated deformities. It has encouraged open discussion on all topics and, in particular, has tried to be the seed-bed for new ideas. The members are spread around the world and include people from all areas of academia as well as the most important people, the patients themselves. Most notably, application of the ideas and results of the research has always been at the forefront of the discussions. This paper was conceived with the idea of evaluating the impact made by the IRSSD over the last 30 years in the various areas and is intended to create discussion for the upcoming meeting in Montreal regarding future focus: "We are lost over the Atlantic Ocean but we are making good time.

    Integration of kinase and calcium signaling at the level of chromatin underlies inducible gene activation in T cells

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    TCR signaling pathways cooperate to activate the inducible transcription factors NF-κB, NFAT, and AP-1. In this study, using the calcium ionophore ionomycin and/or PMA on Jurkat T cells, we show that the gene expression program associated with activation of TCR signaling is closely related to specific chromatin landscapes. We find that calcium and kinase signaling cooperate to induce chromatin remodeling at ∼2100 chromatin regions, which demonstrate enriched binding motifs for inducible factors and correlate with target gene expression. We found that these regions typically function as inducible enhancers. Many of these elements contain composite NFAT/AP-1 sites, which typically support cooperative binding, thus further reinforcing the need for cooperation between calcium and kinase signaling in the activation of genes in T cells. In contrast, treatment with PMA or ionomycin alone induces chromatin remodeling at far fewer regions (∼600 and ∼350, respectively), which mostly represent a subset of those induced by costimulation. This suggests that the integration of TCR signaling largely occurs at the level of chromatin, which we propose plays a crucial role in regulating T cell activation

    The clock gene <i>Bmal1</i> inhibits macrophage motility, phagocytosis, and impairs defense against pneumonia

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    The circadian clock regulates many aspects of immunity. Bacterial infections are affected by time of day, but the mechanisms involved remain undefined. Here we show that loss of the core clock protein BMAL1 in macrophages confers protection against pneumococcal pneumonia. Infected mice show both reduced weight loss and lower bacterial burden in circulating blood. In vivo studies of macrophage phagocytosis reveal increased bacterial ingestion following Bmal1 deletion, which was also seen in vitro. BMAL1−/− macrophages exhibited marked differences in actin cytoskeletal organization, a phosphoproteome enriched for cytoskeletal changes, with reduced phosphocofilin and increased active RhoA. Further analysis of the BMAL1−/− macrophages identified altered cell morphology and increased motility. Mechanistically, BMAL1 regulated a network of cell movement genes, 148 of which were within 100 kb of high-confidence BMAL1 binding sites. Links to RhoA function were identified, with 29 genes impacting RhoA expression or activation. RhoA inhibition restored the phagocytic phenotype to that seen in control macrophages. In summary, we identify a surprising gain of antibacterial function due to loss of BMAL1 in macrophages, associated with a RhoA-dependent cytoskeletal change, an increase in cell motility, and gain of phagocytic function

    The circadian clock protein REVERBα inhibits pulmonary fibrosis development

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    Pulmonary inflammatory responses lie under circadian control; however, the importance of circadian mechanisms in the underlying fibrotic phenotype is not understood. Here, we identify a striking change to these mechanisms resulting in a gain of amplitude and lack of synchrony within pulmonary fibrotic tissue. These changes result from an infiltration of mesenchymal cells, an important cell type in the pathogenesis of pulmonary fibrosis. Mutation of the core clock protein REVERBα in these cells exacerbated the development of bleomycin-induced fibrosis, whereas mutation of REVERBα in club or myeloid cells had no effect on the bleomycin phenotype. Knockdown of REVERBα revealed regulation of the little-understood transcription factor TBPL1. Both REVERBα and TBPL1 altered integrinβ1 focal-adhesion formation, resulting in increased myofibroblast activation. The translational importance of our findings was established through analysis of 2 human cohorts. In the UK Biobank, circadian strain markers (sleep length, chronotype, and shift work) are associated with pulmonary fibrosis, making them risk factors. In a separate cohort, REVERBα expression was increased in human idiopathic pulmonary fibrosis (IPF) lung tissue. Pharmacological targeting of REVERBα inhibited myofibroblast activation in IPF fibroblasts and collagen secretion in organotypic cultures from IPF patients, thus suggesting that targeting of REVERBα could be a viable therapeutic approach
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