929 research outputs found

    Religieus eklekticisme

    Get PDF
    Rectorale oratie Vrije Universiteit 191

    Interactions and metabolic potential of groundwater microorganisms

    Get PDF
    In oligotrophic environments like groundwater, microorganisms can adapt to the nutrient limited conditions through the development of cooperative or antagonistic interactions, or through the general adaptation and regulation of their metabolism. Microbial communities in groundwater are highly complex and often dominated by microorganisms that lack cultivated representatives, including members of the Candidate Phyla Radiation (CPR). These ultra-small sized bacteria have streamlined genomes that lack metabolic functions thought to be essential for life, suggesting that they depend on other microorganisms for these cellular components. This lifestyle hampers the cultivation of CPR, which traditionally relies upon the isolation of single microorganisms. Thus, understanding the repertoire of interaction mechanisms and the metabolic potential of groundwater bacteria is limited to laboratory investigations of a few isolates or based exclusively on genome-derived information. Collectively, the findings presented within this dissertation demonstrate how groundwater microbial communities are structured and influenced by species interactions as well as by the metabolic potential of individual members. While the predicted role of key players like Cand. Roizmanbacterium ADI133 has significantly contributed to the understanding of groundwater ecology, this dissertation further highlights the importance of trophic interactions in the terrestrial subsurface. However, novel cultivation strategies are needed to learn more about the role of yet uncultivated microorganisms, including the CPR

    Contribution of Postmortem Muscle Biochemistry to the Delivery of Consistent Meat Quality with Particular Focus on the Calpain System

    Get PDF
    Tenderness has been repeatedly reported as the most important quality aspect of meat. However, a number of studies have shown that a significant portion of retail meat can be considered tough. As a consequence, a significant consumer segment is willing to pay a premium for guaranteed tender meat. However, apart from measuring the shear force, there is no reliable method to predict tenderness. Most of the branded meat programs therefore attempt to ensure eating quality by controlling some of the factors that affect tenderness. Meat tenderness is determined by the amount and solubility of connective tissue, sarcomere shortening during rigor development, and postmortem proteolysis of myofibrillar and myofibrillar-associated proteins. Given the effect of postmortem proteolysis on the muscle ultrastructure, titin and desmin are likely key substrates that determine meat tenderness. A large number of studies have shown that the calpain proteolytic system plays a central role in postmortem proteolysis and tenderization. In skeletal muscle, the calpain system consists of at least three proteases, µ-calpain, m-calpain and calpain 3, and an inhibitor of µ- and m-calpain, calpastatin. When activated by calcium, the calpains not only degrade subtrates, but also autolyze, leading to loss of activity. m-Calpain does not autolyze in postmortem muscle and is therefore not involved in postmortem tenderization. Results from a number of studies, including a study on calpain 3 knockout mice, have shown that calpain 3 is also not involved in postmortem proteolysis. However, a large number of studies, including a study on µ-calpain knockout mice, have shown that l-calpain is largely, if not solely, responsible for postmortem tenderization. Research efforts in this area should, therefore, focus on elucidation of regulation of lcalpain activity in postmortem muscle. Discovering the mechanisms of µ-calpain activity regulation and methods to promote µ-calpain activity should have a dramatic effect on the ability of researchers to develop reliable methods to predict meat tenderness and on the meat industry to produce a consistently tender product

    Contribution of Postmortem Muscle Biochemistry to the Delivery of Consistent Meat Quality with Particular Focus on the Calpain System

    Get PDF
    Tenderness has been repeatedly reported as the most important quality aspect of meat. However, a number of studies have shown that a significant portion of retail meat can be considered tough. As a consequence, a significant consumer segment is willing to pay a premium for guaranteed tender meat. However, apart from measuring the shear force, there is no reliable method to predict tenderness. Most of the branded meat programs therefore attempt to ensure eating quality by controlling some of the factors that affect tenderness. Meat tenderness is determined by the amount and solubility of connective tissue, sarcomere shortening during rigor development, and postmortem proteolysis of myofibrillar and myofibrillar-associated proteins. Given the effect of postmortem proteolysis on the muscle ultrastructure, titin and desmin are likely key substrates that determine meat tenderness. A large number of studies have shown that the calpain proteolytic system plays a central role in postmortem proteolysis and tenderization. In skeletal muscle, the calpain system consists of at least three proteases, µ-calpain, m-calpain and calpain 3, and an inhibitor of µ- and m-calpain, calpastatin. When activated by calcium, the calpains not only degrade subtrates, but also autolyze, leading to loss of activity. m-Calpain does not autolyze in postmortem muscle and is therefore not involved in postmortem tenderization. Results from a number of studies, including a study on calpain 3 knockout mice, have shown that calpain 3 is also not involved in postmortem proteolysis. However, a large number of studies, including a study on µ-calpain knockout mice, have shown that l-calpain is largely, if not solely, responsible for postmortem tenderization. Research efforts in this area should, therefore, focus on elucidation of regulation of lcalpain activity in postmortem muscle. Discovering the mechanisms of µ-calpain activity regulation and methods to promote µ-calpain activity should have a dramatic effect on the ability of researchers to develop reliable methods to predict meat tenderness and on the meat industry to produce a consistently tender product

    Hydroxyl-apatite coated hip implants

    Get PDF

    Consciousness in the Universe is Scale Invariant and Implies an Event Horizon of the Human Brain

    Get PDF
    Our brain is not a "stand alone" information processing organ: it acts as a central part of our integral nervous system with recurrent information exchange with the entire organism and the cosmos. In this study, the brain is conceived to be embedded in a holographic structured field that interacts with resonant sensitive structures in the various cell types in our body. In order to explain earlier reported ultra-rapid brain responses and effective operation of the meta-stable neural system, a field-receptive mental workspace is proposed to be communicating with the brain. Our integral nervous system is seen as a dedicated neural transmission and multi-cavity network that, in a non-dual manner, interacts with the proposed supervening meta-cognitive domain. Among others, it is integrating discrete patterns of eigen-frequencies of photonic/solitonic waves, thereby continuously updating a time-symmetric global memory space of the individual. Its toroidal organization allows the coupling of gravitational, dark energy, zero-point energy field (ZPE) as well as earth magnetic fields energies and transmits wave information into brain tissue, that thereby is instrumental in high speed conscious and sub-conscious information processing. We propose that the supposed field-receptive workspace, in a mutual interaction with the whole nervous system, generates self-consciousness and is conceived as operating from a 4th spatial dimension (hyper-sphere). Its functional structure is adequately defined by the geometry of the torus, that is envisioned as a basic unit (operator) of space-time. The latter is instrumental in collecting the pattern of discrete soliton frequencies that provided an algorithm for coherent life processes, as earlier identified by us. It is postulated that consciousness in the entire universe arises through, scale invariant, nested toroidal coupling of various energy fields, that may include quantum error correction. In the brain of the human species, this takes the form of the proposed holographic workspace, that collects active information in a "brain event horizon", representing an internal and fully integral model of the self. This brain-supervening workspace is equipped to convert integrated coherent wave energies into attractor type/standing waves that guide the related cortical template to a higher coordination of reflection and action as well as network synchronicity, as required for conscious states. In relation to its scale-invariant global character, we find support for a universal information matrix, that was extensively described earlier, as a supposed implicate order as well as in a spectrum of space-time theories in current physics. The presence of a field-receptive resonant workspace, associated with, but not reducible to, our brain, may provide an interpretation framework for widely reported, but poorly understood transpersonal conscious states and algorithmic origin of life. It also points out the deep connection of mankind with the cosmos and our major responsibility for the future of our planet.</p

    Bewogen Zorg

    Get PDF

    Risk regulation of tissue engineering in the EU : a political economy of medicine

    Get PDF
    Tissue engineering is an emerging biomedical innovation surrounded by potentiality and risk. Based on documentary analysis and expert interviews, this study discusses different constructions of risk according to main constituencies (scientists, clinicians and manufacturers), the way they prioritise and balance these risks, and how issues are framed as problematic or not. Complexity and uncertainty are the main drivers in this exercise, interpreted in terms of boundary drawing around contested risk domains. This is followed by a discussion of the translation of risk into regulatory policy, by focusing on two recent legislative initiatives by the European Commission: one to control the quality and safety aspects of human tissues and cells (DG SANCO Directive) and the other to facilitate the marketing of tissue engineered products in the EU (DG Enterprise Regulation). These two legislative initiatives aim to overcome the current regulatory lag in Europe, where tissue engineered applications are either unregulated or subject to a broad variety in national controls. This situation is problematic for manufacturers wanting to market their products in Europe, for regulators in evaluating the risks of these technologies and defining an appropriate approval route, and for patients in terms of unequal access to potentially beneficial therapies across the continent. Firmly rooted in ambitions to make the EU a techno-scientific and bio-economic powerhouse, regulation of this domain is troubled by competing agendas of promoting trade versus protecting public health. Social and ethical considerations about the impact of tissue engineering technology allow a reconsideration of the bio-society as alternative model, taking into account the technological as well as social character of innovation.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

    Risk regulation of tissue engineering in the EU: A political economy of medicine

    Get PDF
    Tissue engineering is an emerging biomedical innovation surrounded by potentiality and risk. Based on documentary analysis and expert interviews, this study discusses different constructions of risk according to main constituencies (scientists, clinicians and manufacturers), the way they prioritise and balance these risks, and how issues are framed as problematic or not. Complexity and uncertainty are the main drivers in this exercise, interpreted in terms of boundary drawing around contested risk domains. This is followed by a discussion of the translation of risk into regulatory policy, by focusing on two recent legislative initiatives by the European Commission: one to control the quality and safety aspects of human tissues and cells (DG SANCO Directive) and the other to facilitate the marketing of tissue engineered products in the EU (DG Enterprise Regulation). These two legislative initiatives aim to overcome the current regulatory lag in Europe, where tissue engineered applications are either unregulated or subject to a broad variety in national controls. This situation is problematic for manufacturers wanting to market their products in Europe, for regulators in evaluating the risks of these technologies and defining an appropriate approval route, and for patients in terms of unequal access to potentially beneficial therapies across the continent. Firmly rooted in ambitions to make the EU a techno-scientific and bio-economic powerhouse, regulation of this domain is troubled by competing agendas of promoting trade versus protecting public health. Social and ethical considerations about the impact of tissue engineering technology allow a reconsideration of the bio-society as alternative model, taking into account the technological as well as social character of innovation
    corecore