The Use of Layered Freeform Fabrication Technologies to Produce Tissue Engineering Scaffolds for Skull Patches

Congenital skull defects in infants are difficult to correct using metal plates due to the growth of the skull. Tissue engineering of bone patches could be the answer to help such patients. Custom scaffolds have been designed based on Computed Tomography (CT) images of the patient’s skull. An in-house developed single screw extruder, casting and a commercial laser cutter has been evaluated in the fabrication of pure polycaprolactone (PCL) scaffolds as well as PCL mixed with hydroxyapatite (HA) scaffolds. Evaluation criteria for each process included the ability to maintain an optimal pore size for cells to proliferate, inclusion of micro surface properties for cell adhesion, incorporation of hydroxyapatite, and ability to maintain desired shape. The mechanical properties of the fabricated scaffolds will be presented in this paper as well as initial cell seeding results with human adipose-derived adult stem (hADAS) cells.Mechanical Engineerin

Synchronization in systems with linear, yet nonreciprocal interactions

Synchronization of oscillatory subsystems is a widespread phenomenon in science. It is argued that the presence of nonlinearities is a necessary prerequisite for synchronization. Here, we study synchronization in complex plasmas consisting of microparticles in addition to the plasma. The particles can form 2D crystalline structures. They can melt via mode-coupling instability (MCI), which is a consequence of the effective nonreciprocal interactions. Synchronized particle motion during MCI-melting of 2D plasma crystal was reported in [1]. To disentangle the effects of nonlinearity and nonreciprocity on the emergence of synchronization, we solved numerically the nonlinear and the linearized system. Analyzing the synchronization with a new order parameter [2] reveals that a linearized version of the interaction model exhibits the same synchronization patterns as the full, nonlinear one. Further, theoretical considerations show that nonreciprocal interactions among particles generally provide a mechanism for the selection of dominant wave modes causing the system to show synchronized motion. Thus, we demonstrate numerically and analytically that also linear systems can synchronize and that the nonreciprocity of the interaction is the more decisive property for a n-body system to synchronize. [1] L. Couëdel et al., Phys. Rev. E, 89, 053108 (2014) [2] I. Laut et al., EPL, 110, 65001 (2015

Infinite improbabilities

Die Arbeit untersucht das Zusammenspiel von Science Fiction und Parodie im Werk von Douglas Adams, um zu beweisen, dass verschiedene parodistische Mechanismen in den Romanen operieren, die jeweils verschiedene Zielgruppen ansprechen können. Dies geschieht zunächst durch theoretische Bemerkungen zu Parodie und Science Fiction, welche dann auf die Primärtexte angewendet werden. Dabei lassen sich zwei Hauptformen der Parodie in Adams' Werk gesondert erwähnen, nämlich die genre parody (Genreparodie) und die discourse parody (Diskursparodie). Adams' Romane sind einerseits klar Parodien des Science Fiction- Genres, andererseits wird an zahlreichen Stellen in den Romanen auch Parodie mit Science Fiction verknüpft, um einen stärkeren humoristisch-kritischen Effekt zu erzeugen.This paper analyses the interaction of science fiction and parody in the work of Douglas Adams in order to proof that various parodic mechanisms operate within the narrative that have as their targets different groups of readers. This is done firstly via a discussion of SF and parody in theory and then applying this theory to the primary texts. In doing this, two main forms of parody can be observed in Adams' writing, namely genre parody and discourse parody. Adams' novels are clearly parodies of the science fiction genre. However, there are numerous instances in the novels in which the parody is combined with science fiction in order to strengthen its humorous and critical effects

Hydrogeologic Analysis of a Complex Aquifer System and Impacts of Changes in Agricultural Practices on Nitrate Concentrations in a Municipal Well Field: Woodstock, Ontario

The Thornton Well Field, located in an area of dominantly (~80%) agricultural land-use, produces ~50% of the drinking water for the city of Woodstock. Since the mid 1990?s nitrate concentrations in some of the supply wells are above the Maximum Allowable Concentration (MAC) of 10mg-N/L. The source of the nitrate is believed to be from agricultural fertilizing practices. As response to this problem, the County of Oxford purchased 111 hectares of farmland within the capture zone of the Thornton Well Field. This land is rented back to farmers with restrictions placed on the amount of nitrate fertilizer that can be applied in an attempt to sustainably reduce the nitrate concentrations in the ThorntonWell Field below MAC. The objective of this thesis is to improve the site conceptual hydrogeologic model, both at a spatial scale suitable for numerical analysis through regional groundwater flow modelling (representative distance ~9km) and at a smaller scale (representative distance ~2km) for nitrate transport modelling in the vicinity of the Thornton Well Field and the purchased land. Field investigations aimed to support the site hydrogeologic model involved drilling, geologic logging, and instrumentation of a 72m deep borehole completed to bedrock in the center of the nitrate plume, at the border of the farmland under consideration. The shallow subsurface features encountered during this initial drilling operation were tracked below the farm fields with geophysical tools and additional drilling and core logging throughout the field site. Transient hydraulic head observations in combination with on-site precipitation measurements were used to indicate where a hydraulic connection between ground surface and deeper layers exists, which allow rapid infiltration to occur into a glaciofluvial outwash channel which was identified as one important pathway for nitrate transport to the Thornton Well Field. One receptor at the end of that pathway, the screen of the supply Well 01, was depth-discrete profiled for water inflow and nitrate concentrations to obtain better characteristics of the receptor. A method was developed to estimate the nitrate mass stored in the unsaturated zone below Parcel B, permitting an estimation of the time frame required for flushing the nitrate out of this zone, and the anticipated effects on nitrate concentrations in the supply wells. The spatial distribution of nitrate concentrations in the unsaturated zone and in the aquifer units was analyzed. It was found that the nitrate concentration within the unsaturated zone below Parcel B is ~16mg-N/L, resulting in a total nitrogen mass of ~20t within that zone. It was shown that significant reductions (~10%) in nitrate concentrations in the supply wells of the Thornton Well Field can be achieved, assuming zero nitrate mass influx into the domain from Parcel B. A comprehensive data base was developed to organize, manage, and analyze all site measured data for that purpose, and regional hydrogeologic data from the MOE Water Well Record Database. The contents of this database in conjunction with the MOE Water Well Record Database were used to construct a three-dimensional digital representation of the hydrostratigraphic units at a regional and at a local scale. This three-dimensional hydrostratigraphic unit spatial distribution along with surface watershed information and potentiometric surfaces of the various aquifer units will be used to define a suitable spatial domain and associated boundary conditions for future modelling efforts. This hydrostratigraphic model will serve as basis for predicting the effects of agricultural land-use changes within the capture zone of the Thornton Well Field (Parcel B) on the nitrate concentrations in the supply wells of the Thornton Well Field

Assessing smart locations – the MORECO project

A main criterion of intelligent and smart locations is the fact that they support a resource-saving way of life of the residents. Beside other aspects, the mobility of the residents is a very big part of this lifestyle. In big agglomerations the level of motorization is already decreasing, but in rural regions there is often a lack of public transport options which can be used from the inhabitants instead of their own car. The European co-funded Alpine Space project “MORECO Mobility and residential costs” aims to improve sustainable mobility and to foster better accessibilities by supporting an optimized polycentric settlement development. The mainly addressed target groups are private households, planners, and mobility actors as well as politicians and decision makers. To fit all different needs, special tools were arranged and developed for each target group during the MORECO project. These provided tools within the MORECO tool kit are generally possible to be used in every region or municipality to be a part of an overall and strategic mobility management. The adaption level of the tools can be fitted to all local framework conditions as far as the necessary data is available. In regions where the mobility behavior is mainly car-oriented the tools can be helpful and motivating to improve sustainable mobility offers, especially because there is mostly no possibility to stop directly future urban sprawl according to law. The practical results out of the project can be an incentive for other European regions and municipalities which also prioritize an improvement in the field of sustainable mobility

Übungsaufgaben zu Öffentliche Finanzen

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Gene expression of catabolic inflammatory cytokines peak before anabolic inflammatory cytokines after ACL injury in a preclinical model

Background: The response of the joint to anterior cruciate ligament (ACL) injury has not been fully characterized. In particular, the characterization of both catabolic factors, including interleukin-6 (IL-6), interleukin-8 (IL-8), and markers of ongoing tissue damage (CRP), and anabolic factors, including vascular endothelial growth factor (VEGF), transforming growth factor β-induced (TGFβI), and the presence of CD163+ macrophages, have not been well defined. In this study, we hypothesized ACL injury would catalyze both catabolic and anabolic processes and that these would have different temporal profiles of expression. Methods: Adolescent Yucatan minipigs were subjected to ACL transection. Within the joint, gene expression levels of IL-6, IL-8, VEGF, and TGFβI were quantified in the synovium, ligament, and provisional scaffold located between the torn ligament ends at days 1, 5, 9, and 14 post-injury. Macrophage infiltration was also assessed in the joint tissues over the two week period. Serum C-reactive protein (CRP) levels were measured at multiple time points between 1 hour to 14 days after injury. Results: Increases in IL-6 and IL-8 gene expression peaked at day 1 after injury in the synovium and ligament. CRP levels were significantly increased at day 3 before returning to pre-injury levels. VEGF and TGFβI gene expression did not significantly increase until day 9 in the synovium and were unchanged in the other tissues. CD163+ macrophages increased in the ligament and synovium until day 9. Conclusion: Taken together, these results suggest that the response within the joint is primarily catabolic in the first three days after injury, switching to a more anabolic phase by nine days after injury. The effect of medications which alter these processes may thus depend on the timing of administration after injury

Life stage-specific hydropeaking flow rules

ReviewPeak-operating hydropower plants are usually the energy grid’s backbone by providing flexible energy production. At the same time, hydropeaking operations are considered one of the most adverse impacts on rivers, whereby aquatic organisms and their life-history stages can be affected in many ways. Therefore, we propose specific seasonal regulations to protect ecologically sensitive life cycle stages. By reviewing hydropeaking literature, we establish a framework for hydrological mitigation based on life-history stages of salmonid fish and their relationship with key parameters of the hydrograph. During migration and spawning, flows should be kept relatively stable, and a flow cap should be implemented to prevent the dewatering of spawning grounds during intragravel life stages. While eggs may be comparably tolerant to dewatering, post-hatch stages are very vulnerable, which calls for minimizing or eliminating the duration of drawdown situations and providing adequate minimum flows. Especially emerging fry are extremely sensitive to flow fluctuations. As fish then grow in size, they become less vulnerable. Therefore, an ‘emergence window’, where stringent thresholds on ramping rates are enforced, is proposed. Furthermore, time of day, morphology, and temperature changes must be considered as they may interact with hydropeaking. We conclude that the presented mitigation framework can aid the environmental enhancement of hydropeaking rivers while maintaining flexible energy productioninfo:eu-repo/semantics/publishedVersio