3,337 research outputs found
Postnatal development of articular cartilage
No full textArticular cartilage (AC) is the thin layer of tissue that covers the ends of the bones in the synovial joints in mammals. Functional adult AC has depth-dependent mechanical properties that are not yet present at birth. These depth-dependent mechanical properties in adult life are the result of a depth-dependent composition and structure that develops in postnatal life. Our knowledge on how postnatal AC remodelling proceeds, and how the functional depth-dependent mechanical properties develop in postnatal life is still limited. In this thesis, we investigated the properties of the postnatal collagen network in AC, and the contribution of postnatal collagen network remodelling to the adult depth-dependent mechanical properties of AC. We used horses and (mostly) sheep as experimental animals to obtain measurements on three parameters of the postnatal collagen network (predominant collagen fibril orientation, collagen densities and collagen network anisotropy). We used a composition-based finite element model for computational analysis of the role of this collagen network in the postnatal development of depth-dependent mechanical properties. We first investigated how collagen structure in AC affects the parameters that are measured by quantitative polarised light microscopy (qPLM), because qPLM is the most popular technique to investigate properties of the collagen network in AC. We quantified the contributions of the three collagen network parameters (orientation, density and anisotropy) to the measured predominant fibril orientation and the measured total tissue birefringence (retardance), and showed that collagen network anisotropy can be quantified when the retardance from polarised light microscopy is corrected for collagen densities. In the study on horses, we investigated differences in predominant collagen orientation for equine articular cartilage in stillborn and adult animals with scanning electron microscopy and quantitative polarised light microscopy (qPLM). In the study on sheep, we first investigated the predominant collagen orientation in animals divided over ten sample points between birth and maturity (72 weeks) with qPLM. Both studies confirmed the remark by Archer et al. [Archer2003] that the collagen fibrils in perinatal animals lie predominantly parallel to the articular surface, and we confirmed and quantified the adult 'Benninghoff' structure in the mature animals in both studies. We further observed a transitional layer with weak fibril anisotropy in the perinatal animals that is not correlated to changes in predominant collagen fibril orientation as in the adult Benninghoff structure. To investigate the contribution of collagen reorientation to the development of depth-dependent mechanical properties, we implemented the results on postnatal predominant collagen fibril orientation in the sheep in a composition-based finite element model. We described the interactions between collagen orientation, free swelling strains, osmotic pressures and effective AC stiffness in confined compression. Based on the results, we hypothesised that collagen densities increase most in the deep tissue due to increased collagen fibril strains that result from postnatal collagen fibril reorientation. In sheep, we measured collagen densities with Fourier transform infrared micro-spectroscopy. Collagen density increased in postnatal life, and they increased most in the deep tissue (near the bone), which supported our earlier hypothesis. Perinatal animals showed a valley in collagen densities near the articular surface, i.e. at the position of the transitional layer. We showed that this valley disappears in early postnatal life. We corrected the qPLM retardance from our sheep data with the collagen densities from the sheep data to assess collagen network anisotropy. The results showed that anisotropy is relatively constant in the deep tissue, and that anisotropy is stronger in the transitional layer of perinatal animals compared with the transitional layer of adult animals. To investigate interactions in postnatal collagen network remodelling, we implemented the three collagen network parameters (orientation, density and anisotropy) that we obtained from the sheep in the finite element model. Based on the results, we suggested different functional roles for the three collagen network parameters: collagen fibril reorientation contributes most to the development of depth-dependent mechanical properties, collagen density increases appear to equalise collagen fibril strains, and the weak anisotropy in the transitional layer appears to smooth gradients in the mechanical state of the tissue in adult animals. <br/
Report of Governor Johan Rising, 1655, on New Sweden
No full textGovernor Johan Rising reports to the Swedish government and royalty on the status of New Sweden (present-day New Jersey). He also reports on other Swedish colonies in the area. He asks that single women and skilled tradesmen be sent to the colonies. Rising also reports that attacks from neighboring Indian tribes are increasing. He has found some protection by forming an alliance with English settlers, but the cost is high, and his colony owes the English money and supplies. Rising asks that Sweden send them money so that they can pay off their debts, build ships that would establish a trading dominance with the West Indies, and cultivate land and crops to gain more profit. Reports from New World governors were sent back to their native countries via ships. Rising sent this report in June of 1655, but Sweden did not recieve the report until November of 1655. This article is part of a Primary Source Material collection compiled by the New Sweden Commemorative Commission in 1988
Report of Governor Johan Printz, 1647, on New Sweden
No full textGovern Johan Printz, the governor of New Sweden (later to become New Jersey), reports on the status of the colony and the settlers. Many freemen have arrived to settle in New Sweden, but the criminals and military men who were conscripted to the colony want to return to Sweden. Of the freemen, very few are skilled, so Governor Printz asks that blacksmiths, tanners, tailors, carpenters, and butchers be sent to the colony. Additionally, he asks for single women. Printz also reports on two new Swedish colonies that have been established along the Delaware River. However, Dutch settlers have become very aggressive by re-purchasing land from the Indians that the Swedish had already bought. They are also interrupting trade between the Swedes and the Indians, as well as instigating the Indians to attack the Swedes. Printz directed the construction of some storage houses along common trade routes to win back trade from the Indians. However, fighting has erupted between different Native tribes as each tries to establish dominance in trading with the colonies. This article is part of a Primary Source Material collection compiled by the New Sweden Commemorative Commission in 1988
Relation of the surrender of New Sweden, by Governor Johan Clason Rising, 1655
No full textGovernor Johan Rising of New Sweden reports to Sweden on the August 1655 Dutch attack on New Sweden's Fort Christina. The Dutch traveled from New Amsterdam (present-day New York) and easily captured a New Sweden outpost. Rising sent men to the outpost to fend of the Dutch, but the Dutch defeated them and took them as prisoners, leaving Fort Christina without fighting men and supplies. The Dutch then put the Fort under seige. A few days later, Rising surrendered the Fort. He and the Swedish colonists were ordered to either return to Sweden, or to remain in the New World in service to the Dutch. This article is part of a Primary Source Material collection compiled by the New Sweden Commemorative Commission in 1988
The past, present and future of social media in project management
No full textGreen Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Integral Design & Managemen
Musketry : the Anglo-Boer War experience
No full textCITATION: Ellis, J. 2000. Musketry : the Anglo-Boer War experience. Historia, Historia, 45(2).The original publication is available at https://upjournals.up.ac.zaThe conflict between the Zuid-Afrikaanse Republic (ZAR) and Great Britain was not the first experience the British had of Boer tactics and musketry. The British had the opportunity to study the military system and approach to warfare as practised by the Boers for almost a hundred years. Still, they suffered severe losses against a "lesser" enemy who understood better the employment of the new smokeless magazine rifles. In order to understand the imbalance in the effectiveness of British and Boer firepower, the background of both the British and Boer soldiers opposing each other on the battlefields of southern Africa is illustrated. In doing so the author draws a comparison between the British soldier and his Boer opponent.Publisher's versio
An operationalization of Stevenson’s conceptualization of entrepreneurship as opportunity-based firm behavior
No full textThis is the author-version of article published as: Brown, Terrence and Davidsson, Per and Wiklund, Johan (2001) An operationalization of Stevenson’s conceptualization of entrepreneurship as opportunity-based firm behavior. Strategi
Enhanced financial mechanisms for post 2012 mitigation
No full textDespite the many calls to reform the CDM, its conceptual underpinnings are strong and it will most likely survive in the post-2012 climate regime. Some modifications may be considered in the short term to strengthen the effectiveness and transparency of the mechanism without modifying the Marrakesh Accords. In the medium term substantially increased mitigation efforts in developing countries may require a combination of three possible financial mechanisms: the current activity-based CDM albeit improved, a second market mechanism that would seek to improve the long term emission trends of developing countries by promoting broad based emission reduction programs primarily in the private sector, and a third financial mechanism outside of the market which would be an incentive for the adoption of policy changes leading to a low carbon path, but where emission reductions would not be used as international offsets.Environmental Economics&Policies,Carbon Policy and Trading,Montreal Protocol,Energy and Environment,Environment and Energy Efficiency
Social media for improving metro rail project operations
No full textGreen Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Integral Design & Managemen
The social challenges of low carbon development
No full textThis book explores the social implications and challenges of low-carbon development. The argument of the book is that a broad understanding of low-carbon development is essential for mitigating climate change and enabling development in a carbon-constrained world, but there are risks that low-carbon development might come at a price that is both social and economic. These risks need to be carefully assessed and reduced. The main aim of the book is to explore, critically analyse and propose different ways of understanding low-carbon development from a social perspective in both developed and developing countries. The author uses concepts such as low-carbon development, social policy, sustainable development and environmental justice to understand the social implications of low-carbon development projects. The book first elaborates the need to understand the social issues and challenges of low-carbon development in both developed and developing countries. It then discusses five contemporary challenges of low-carbon development: * the social consequences of Chinese hydropower dams in the Mekong region; * the cost of the transition to renewable energies such as wind energy in Germany; * the challenges of carbon offsetting in Brazil; * the nexus of fuel-inefficient housing and fuel poverty in England; * solar power for refugees in Africa. The book fills a crucial gap for researchers, postgraduates, practitioners and policy-makers in the fields of climate change, development and social policy. Johan Nordensvard is a Lecturer in Social Policy at the University of Southampton, UK
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