1,158 research outputs found
The Maine State House: A Brief History and Guide
This is a building for all the people of Maine, which also welcomes visitors to the state who wish to share in this expression of our heritage.https://digitalcommons.usm.maine.edu/mhpc-docs/1005/thumbnail.jp
A generalized approach for computation of near field radiation pattern of an antenna
A generalized procedure in the form of an analytical formulation for the determination of radiation pattern of an antenna at any arbitrary distance which covers the near field as well as far field is presented in this paper. With the prior knowledge of either the current or field distribution on the radiating aperture, the proposed near field analysis is generic and can be applied for wide variety of antenna elements. The underlying principle of the generalized procedure is tantamount to considering the radiating aperture as an array of point electric and magnetic dipoles. The validity and novelty of the proposed new approach have been substantiated considering an open ended circular cylindrical waveguide and a conical horn as case studies and treating the far field as a special case of near field with pertinent distance criterion. The effect of change in the distance of observation ranging from reactive near field to far field on the radiation patterns of these antennas has also been discussed. The simulation studies reveal that the depicted normalized phase patterns of both the circular waveguide and conical horn follow the changes in the profile of the corresponding amplitude patterns
Vascular endothelial growth factor can signal through platelet-derived growth factor receptors
Vascular endothelial growth factor (VEGF-A) is a crucial stimulator of vascular cell migration and proliferation. Using bone marrow–derived human adult mesenchymal stem cells (MSCs) that did not express VEGF receptors, we provide evidence that VEGF-A can stimulate platelet-derived growth factor receptors (PDGFRs), thereby regulating MSC migration and proliferation. VEGF-A binds to both PDGFRα and PDGFRβ and induces tyrosine phosphorylation that, when inhibited, results in attenuation of VEGF-A–induced MSC migration and proliferation. This mechanism was also shown to mediate human dermal fibroblast (HDF) migration. VEGF-A/PDGFR signaling has the potential to regulate vascular cell recruitment and proliferation during tissue regeneration and disease
Broaching the brook : daylighting, community and the ‘stickiness’ of water
Over the last century, under the modern hydraulic model, waterways across the world have been heavily canalized and culverted, driven into underground pipes, drains and sewers. This hydraulic approach has hardwired an isolated water network into the urban fabric, fragmenting erstwhile patterns and dynamics of life, both human and nonhuman. Ecologically, it has been hugely damaging, reducing water quality and biotic diversity, but also socially, disconnecting citizens from the waterways that service and characterize the city. Consequently, since the 1990s, waterway restoration has become widespread as a design solution to degraded rivers and streams, reinstating compromised hydrological, geomorphological and ecological processes. Deculverting or ‘daylighting’, the focus of this paper, is a radical form of restoration, opening up subterranean, culverted waterways often forgotten by communities above ground. Yet, as this paper emphasizes, waterway restoration has tended to privilege ecological over social objectives, while public engagement in project conceptualization has been limited, conducted ‘downstream’ subsequent to planning and design stages. Restoration schemes have therefore tended to reflect the concerns of professionals rather than communities, overlooking their potential for social renewal and change. Drawing on workshop data collected through participatory mapping exercises, this paper explores the case for daylighting a culverted brook in Urmston, Greater Manchester, focusing in particular on the preferences, concerns and knowledge of local residents. The paper compares professional and community perspectives on the preferred scheme design and potential benefits of daylighting, drawing out differences and tensions between them, temporarily ‘unblackboxing’ the brook. It is ventured that daylighting can unleash the social ‘stickiness’ of water, its proclivity to draw and bind together, to revitalize the park, enhancing connection to wildness, attachment to place and sense of community. This is particularly crucial in the face of decreased local authority funding and related crises in park management
Megaloblastic anaemia, diabetes and deafness in a two-year old child
Megaloblastic anaemia in childhood usually occurs as a result of dietary folate deficiency or, rarely, congenital disorders of vitamin B12 metabolism. We present a 2-year-old girl with megaloblastic anaemia and insulin-dependent diabetes mellitus, both of which proved responsive to pharmacological doses of thiamine. She was also found to have sensorineural hearing loss. Also known as Rogers’ syndrome, thiamine-responsive megaloblastic anaemia is the result of inactivating mutations in a gene encoding a thiamine transporter. A clinical diagnosis is supported by characteristic bone marrow findings and can be confirmed by demonstrating apoptosis in skin fibroblasts cultured in thiamine-depleted medium. Where available, DNA sequencing is definitive. There is rapid reticulocytosis after thiamine administration. We recommend a trial of therapy for megaloblastic anaemia not responding to folate and vitamin B12, especially in a deaf and/or diabetic child
Megaloblastic anaemia, diabetes and deafness in a 2-year old child
Megaloblastic anaemia in childhood usually occurs as a result of dietary folate deficiency or, rarely, congenital disorders of vitamin B12 metabolism. We present a 2-year-old girl with megaloblastic anaemia and insulin-dependent diabetes mellitus, both of which proved responsive to pharmacological doses of thiamine. She was also found to have sensorineural hearing loss. Also known as Rogers’ syndrome, thiamine-responsive megaloblastic anaemia is the result of inactivating mutations in a gene encoding a thiamine transporter. A clinical diagnosis is supported by characteristic bone marrow findings and can be confirmed by demonstrating apoptosis in skin fibroblasts cultured in thiamine-depleted medium. Where available, DNA sequencing is definitive. There is rapid reticulocytosis after thiamine administration. We recommend a trial of therapy for megaloblastic anaemia not responding to folate and vitamin B12, especially in a deaf and/or diabetic child
2-Pyridyl substituents enhance the activity of palladium-phospha-adamantane catalysts for the methoxycarbonylation of phenylacetylene
The pyridyl-N in Pt and Pd complexes of CgP(2-py) can be protonated or can coordinate to form a P,N-chelate; these features are linked with the carbonylation catalysis results.</p
The flux and provenance of dust delivered to the SW Pacific during the last glacial maximum
The funding for the TAN1106 voyage was from the Coasts and Oceans Physical Resources program awarded to the National Institute of Water and Atmospheric Research, New Zealand. This work was funded by NERC studentship NE/L002531/1 to R.S. and NERC grant NE/J021075/1 to G.L.F. R.G. and A.B. were supported by NERC grant NE/M004619/1 awarded to A.B.Atmospheric dust is a primary source of iron (Fe) to the open ocean, and its flux is particularly important in the high nutrient, low chlorophyll (HNLC) Southern Ocean where Fe currently limits productivity. Alleviation of this Fe limitation in the Subantarctic Zone of the Atlantic by increased dust-borne Fe supply during glacial periods has been shown to increase primary productivity. However, previous work has found no such increase in productivity in the Pacific sector. In order to constrain the relative importance of Southern Ocean Fe fertilization on glacial-interglacial carbon cycles, records of dust fluxes outside of the Atlantic sector of the Southern Ocean at the Last Glacial Maximum (LGM) are required. Here we use grain size and U-series analyses to reconstruct lithogenic and CaCO3 fluxes, and Nd, Sr and Pb isotopes to ascertain the provenance of terrigenous material delivered to four deep-water cores in the SW Pacific Ocean over the last ~30kyr. We find evidence for an increase in the relative proportion of fine-grained (0.5-12 ?m) terrigenous sediment and higher detrital fluxes during the LGM compared to the Holocene. The provenance of the LGM dust varied spatially, with an older, more "continental" signature (low εNd, high 87Sr/86Sr) sourced from Australia in the northern cores, and a younger, more volcanogenic source in the southern cores (high εNd, low 87Sr/86Sr), likely sourced locally from New Zealand. Given this increase in lithogenic flux to the HNLC subantarctic Pacific Southern Ocean during the LGM, factors besides Fe-supply must have regulated the biological productivity here.Publisher PDFPeer reviewe
Cell-matrix biology in vascular tissue engineering
We are developing biocompatible small-calibre vascular substitutes based on polymeric scaffolds that incorporate cell-matrix signals to enhance vascular cell attachment and function. Our graft scaffold comprises an outer electrostatically spun porous polyurethane layer seeded with smooth muscle cells, and a luminal polycaprolactone layer for endothelial cell attachment. Vascular cell adhesion properties of three vascular elastic fibre molecules, tropoelastin, fibrillin-1 and fibulin-5, have been defined, and adhesion fragments optimized. These fragments are being used to coat the scaffolds to enhance luminal endothelial cell attachment, and to regulate smooth muscle cell attachment and function. Tropoelastin-based cell seeding materials are also being developed. In this way, vascular cell-matrix biology is enhancing graft design
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