175 research outputs found
Money market mutual funds : a reaction to government regulations or a lasting financial innovation?
An abstract for this article is not availableMutual funds
Money market mutual funds and other short-term investment pools
Mutual funds ; Money market
Automated classification metrics for energy modelling of residential buildings in the UK with open algorithms
Estimating residential building energy use across large spatial extents is vital for identifying and testing effective strategies to reduce carbon emissions and improve urban sustainability. This task is underpinned by the availability of accurate models of building stock from which appropriate parameters may be extracted. For example, the form of a building, such as whether it is detached, semi-detached, terraced etc and its shape may be used as part of a typology for defining its likely energy use. When these details are combined with information on building construction materials or glazing ratio, it can be used to infer the heat transfer characteristics of different properties. However, these data are not readily available for energy modelling or urban simulation. Although this is not a problem when the geographic scope corresponds to a small area and can be hand-collected, such manual approaches cannot be easily applied at the city or national scale. In this paper, we demonstrate an approach that can automatically extract this information at the city scale using off-the-shelf products supplied by a National Mapping Agency. We present two novel techniques to create this knowledge directly from input geometry. The first technique is used to identify built form based upon the physical relationships between buildings. The second technique is used to determine a more refined internal/external wall measurement and ratio. The second technique has greater metric accuracy and can also be used to address problems identified in extracting the built form. A case study is presented for the City of Nottingham in the United Kingdom using two data products provided by the Ordnance Survey of Great Britain (OSGB): MasterMap and AddressBase. This is followed by a discussion of a new categorisation approach for housing form for urban energy assessment
Conditional Ablation of Macrophages Halts Progression of Crescentic Glomerulonephritis
The presence of macrophages in inflamed glomeruli of rat kidney correlates with proliferation and apoptosis of resident glomerular mesangial cells. We assessed the contribution of inflammatory macrophages to progressive renal injury in murine crescentic glomerulonephritis (GN). Using a novel transgenic mouse (CD11b-DTR) in which tissue macrophages can be specifically and selectively ablated by minute injections of diphtheria toxin, we depleted renal inflammatory macrophages through days 15 and 20 of progressive crescentic GN. Macrophage depletion reduced the number of glomerular crescents, improved renal function, and reduced proteinuria. Morphometric analysis of renal tubules and interstitium revealed a marked attenuation of tubular injury that was associated with reduced proliferation and apoptosis of tubular cells. The population of interstitial myofibroblasts decreased after macrophage depletion and interstitial fibrosis also decreased. In the presence of macrophages, interstitial myofibroblasts exhibited increased levels of both proliferation and apoptosis, suggesting that macrophages act to support a population of renal myofibroblasts in a high turnover state and in matrix deposition. Finally, deletion of macrophages reduced CD4 T cells in the diseased kidney. This study demonstrates that macrophages are key effectors of disease progression in crescentic GN, acting to regulate parenchymal cell populations by modulating both cell proliferation and apoptosis
Identification of Novel Fibrosis Modifiers by InĀ Vivo siRNA Silencing.
Fibrotic diseases contribute to 45% of deaths in the industrialized world, and therefore a better understanding of the pathophysiological mechanisms underlying tissue fibrosis is sorely needed. We aimed to identify novel modifiers of tissue fibrosis expressed by myofibroblasts and their progenitors in their disease microenvironment through RNA silencing inĀ vivo. We leveraged novel biology, targeting genes upregulated during liver and kidney fibrosis in this cell lineage, and employed small interfering RNA (siRNA)-formulated lipid nanoparticles technology to silence these genes in carbon-tetrachloride-induced liver fibrosis in mice. We identified five genes, Egr2, Atp1a2, Fkbp10, Fstl1, and Has2, which modified fibrogenesis based on their silencing, resulting in reduced Col1a1 mRNA levels and collagen accumulation in the liver. These genes fell intoĀ different groups based on the effects of their silencing on a transcriptional mini-array and histological outcomes. Silencing of Egr2 had the broadest effects inĀ vivo and also reduced fibrogenic gene expression in a human fibroblast cell line. Prior to our study, Egr2, Atp1a2, and Fkbp10 had not been functionally validated in fibrosis inĀ vivo. Thus, our results provide a major advance over the existing knowledge of fibrogenic pathways. Our study is the first example of a targeted siRNA assay to identify novel fibrosis modifiers inĀ vivo
Intrinsic Epithelial Cells Repair the Kidney after Injury
SummaryUnderstanding the mechanisms of nephron repair is critical for the design of new therapeutic approaches to treat kidney disease. The kidney can repair after even a severe insult, but whether adult stem or progenitor cells contribute to epithelial renewal after injury and the cellular origin of regenerating cells remain controversial. Using genetic fate-mapping techniques, we generated transgenic mice in which 94%ā95% of tubular epithelial cells, but no interstitial cells, were labeled with either Ī²-galactosidase (lacZ) or red fluorescent protein (RFP). Two days after ischemia-reperfusion injury (IRI), 50.5% of outer medullary epithelial cells coexpress Ki67 and RFP, indicating that differentiated epithelial cells that survived injury undergo proliferative expansion. After repair was complete, 66.9% of epithelial cells had incorporated BrdU, compared to only 3.5% of cells in the uninjured kidney. Despite this extensive cell proliferation, no dilution of either cell-fate marker was observed after repair. These results indicate that regeneration by surviving tubular epithelial cells is the predominant mechanism of repair after ischemic tubular injury in the adult mammalian kidney
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TLR-2/TLR-4 TREM-1 Signaling Pathway Is Dispensable in Inflammatory Myeloid Cells during Sterile Kidney Injury
Inflammatory macrophages are abundant in kidney disease, stimulating repair, or driving chronic inflammation and fibrosis. Damage associated molecules (DAMPs), released from injured cells engage pattern recognition receptors (PRRs) on macrophages, contributing to activation. Understanding mechanisms of macrophage activation during kidney injury may lead to strategies to alleviate chronic disease. We identified Triggering-Receptor-in-Myeloid-cells (TREM)-1, a regulator of TLR signaling, as highly upregulated in kidney inflammatory macrophages and tested the roles of these receptors in macrophage activation and kidney disease. Kidney DAMPs activated macrophages in vitro, independently of TREM-1, but partially dependent on TLR-2/ā4, MyD88. In two models of progressive interstitial kidney disease, TREM-1 blockade had no impact on disease or macrophage activation in vivo, but TLR-2/ā4, or MyD88 deficiency was anti-inflammatory and anti-fibrotic. When MyD88 was mutated only in the myeloid lineage, however, there was no bearing on macrophage activation or disease progression. Instead, TLR-2/ā4 or MyD88 deficiency reduced activation of mesenchyme lineage cells resulting in reduced inflammation and fibrosis, indicating that these pathways play dominant roles in activation of myofibroblasts but not macrophages. To conclude, TREM-1, TLR2/4 and MyD88 signaling pathways are redundant in myeloid cell activation in kidney injury, but the latter appear to regulate activation of mesenchymal cells
Inhibition of Ī±vĪ²5 Integrin Attenuates Vascular Permeability and Protects against Renal Ischemia-Reperfusion Injury
Ischemia-reperfusion injury (IRI) is a leading cause of AKI. This common clinical complication lacks effective therapies and can lead to the development of CKD. The Ī±vĪ²5 integrin may have an important role in acute injury, including septic shock and acute lung injury. To examine its function in AKI, we utilized a specific function-blocking antibody to inhibit Ī±vĪ²5 in a rat model of renal IRI. Pretreatment with this anti-Ī±vĪ²5 antibody significantly reduced serum creatinine levels, diminished renal damage detected by histopathologic evaluation, and decreased levels of injury biomarkers. Notably, therapeutic treatment with the Ī±vĪ²5 antibody 8 hours after IRI also provided protection from injury. Global gene expression profiling of post-ischemic kidneys showed that Ī±vĪ²5 inhibition affected established injury markers and induced pathway alterations previously shown to be protective. Intravital imaging of post-ischemic kidneys revealed reduced vascular leak with Ī±vĪ²5 antibody treatment. Immunostaining for Ī±vĪ²5 in the kidney detected evident expression in perivascular cells, with negligible expression in the endothelium. Studies in a three-dimensional microfluidics system identified a pericyte-dependent role for Ī±vĪ²5 in modulating vascular leak. Additional studies showed Ī±vĪ²5 functions in the adhesion and migration of kidney pericytes in vitro Initial studies monitoring renal blood flow after IRI did not find significant effects with Ī±vĪ²5 inhibition; however, future studies should explore the contribution of vasomotor effects. These studies identify a role for Ī±vĪ²5 in modulating injury-induced renal vascular leak, possibly through effects on pericyte adhesion and migration, and reveal Ī±vĪ²5 inhibition as a promising therapeutic strategy for AKI
Livestock Raiding Among the Pastoral Turkana of Kenya:
Summaries The long?persisting and erroneous conception of famine among the pastoral Turkana of Kenya as an essentially ādrought?drivenā event has given way to growing recognition today of the key role which livestock raiding plays in the breakdown of coping strategies. However, this article argues that the phenomenon of cattle raids per se is not the problem. Rather it is the fashion in which raiding has been transformed over the years, from a quasi?cultural practice with important livelihood?enhancing functions, into more predatory forms driven by an economic logic and modern forms of violence. This article seeks to understand predatory raiding and its effects in terms of the changing functions which raiding serves within pastoral society and, increasingly, outside it. The article uses a model of armed conflict and livelihood vulnerability to illustrate how violence and the threat of violence interact with drought to undermine the coping strategies of herders
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