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Appropriate load-bearing function of soft connective tissues is provided by their nonlinear and often anisotropic mechanical properties. Recapitulating this complex mechanical behaviour in tissue-engineered structures is particularly crucial, as deviation from normal native tissue mechanics can trigger pathological biomechanical pathways, leading to adverse tissue remodelling and dysfunction. Here we report a novel method combining computational modelling, melt electrowriting (MEW), and design of experiments (DOE) to generate scaffolds composed of sinusoidal fibres with prescribed biaxial tensile mechanical properties, recapitulating the distinct nonlinear, anisotropic stress-strain behaviour of three model soft connective tissues: adult aortic valve, pediatric pulmonary valve, and pediatric pericardium. The fibrous scaffolds were fabricated using MEW of polycaprolactone, and their architectures were optimized using DOE and regression models for superior control over scaffold architecture to yield prescribed mechanics. Cell-laden fibrin hydrogel was cast within the fibrous scaffolds to generate hybrid tissue sheets, suitable for connective tissue engineering. The composition of the cell-laden hydrogel and its cell density were optimized to cause minimal contraction, support high cell viability and growth, and minimally contribute to the hybrid tissue biaxial mechanical properties, which were governed by the prescribed MEW scaffold architecture. This high-fidelity approach recapitulates biaxial mechanical properties over a broad range of mechanical nonlinearity and anisotropy and is generalizable for programmed fabrication in a variety of textile, biomaterial, and tissue engineering applications.

Since the first stoma appeared about 400 million years ago, moisture exchange between lands and the atmosphere extends into the root zone. However, due to its invisibility from the surface, root distribution and its temporal variation are difficult to estimate, which greatly hinders investigation of root zone moisture dynamics, soil-plant water relations, and transpiration modelling. Plant water potential reflects dynamic water condition in vegetation, which is determined by moisture supply in the root zone, atmospheric demand, and plant physiological control. Thus, dynamic water potential can provide a “periscope” to observe root zone hydraulic conditions. Based on this hydraulic connection in the soil-plant-atmosphere continuum (SPAC), plant individuals work very likely as “observation wells” to the whole root zone at predawn, and as “pumping test wells” in daytime. Meanwhile, stable isotopic composition of water in plant xylem approximately reflects the isotopic signature of bulk root accessible moisture. These hydraulic and isotopic root-zone periscopes provide information to estimate root-zone and plant hydraulic states and their dynamics, and hydraulic properties. In this presentation, we will show how this root-zone periscope concept, based on continuous monitoring of plant water potential, sapflow, and/or isotopic composition of xylem water, has been successfully applied in SPAC model development, root water uptake model improvement, transpiration model parameterisation, as well as investigation of ecohydrological separation.

Bacteria that migrate (extravasate) out of the bloodstream during vascular dissemination can cause secondary infections in many tissues and organs, including the brain, heart, liver, joints, and bone with clinically serious and sometimes fatal outcomes. The mechanisms by which bacteria extravasate through endothelial barriers in the face of blood flow-induced shear stress are poorly understood, in part because individual bacteria are rarely observed traversing endothelia in vivo, and in vitro model systems inadequately mimic the vascular environment. To enable the study of bacterial extravasation mechanisms, we developed a transmembrane microfluidics device mimicking human blood vessels. Fast, quantitative, three-dimensional live cell imaging in this system permitted single-cell resolution measurement of the Lyme disease bacterium Borrelia burgdorferi transmigrating through monolayers of primary human endothelial cells under physiological shear stress. This cost-effective, flexible method was 10,000 times more sensitive than conventional plate reader-based methods for measuring transendothelial migration. Validation studies confirmed that B. burgdorferi transmigrate actively and strikingly do so at similar rates under static and physiological flow conditions. This method has significant potential for future studies of B. burgdorferi extravasation mechanisms, as well as the transendothelial migration mechanisms of other disseminating bloodborne pathogens.

This paper aims to contribute to the ongoing debate on the use of resource accounting tools in regional policy-making. The Northern Limits project applied material flow analysis (MFA) and ecological footprinting (EF) to regional policy-making in Northern Ireland over a number of years. The early phase of the research informed the regions first sustainable development strategy which was published in 2006 with key targets relating to the EF and improving the resource efficiency of the economy. Phase II identified the next steps required to address data availability and quality and the use of MFA and EF in providing a measurement and monitoring framework for the strategy and the development of the strategy implementation plan. The use of MFA and EF in sustainable regional policy-making and the monitoring of its implementation is an ongoing process which has raised a number of research issues which can inform the ongoing application and development of these and other resource accounting tools to within Northe...

The Newark Island Layered Intrusion (NILI) is a Middle Proterozoic (1305 ± 5 Ma; U-Pb zircon) mafic pluton on the eastern edge of the Nain Anorthosite Complex, Labrador. The NILI has been subdivided by Wiebe (1988) into a stratigraphically lower, earlier, layered series (LS) and a later hybrid series (HS). Although grossly similar in mineralogy, the REE and Sr isotope systematics of the LS and HS cumulates differ dramatically. All but one of the LS cumulates exhibit low total REE (La = 5 to 8 X chondrites) and a large positive Eu anomaly, indicative of an adcumulus to mesocumulus origin, with plagioclase and olivine as the expected major cumulus phases. Analyzed HS cumulates and other nonchilled rocks also contain principally olivine and plagioclase as cumulus phases, yet exhibit much higher abundances of the REE (La = 40 to 90 X chondrites), are LREE enriched ((Ce/Sm)n = 1.78), and show only a small positive Eu anomaly that diminishes with increasing REE abundances. No assemblage of mafic minerals alone ...