19 research outputs found

    The techno-ecological practice as the politics of ontological coalitions

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    The paper focuses on the art projects aimed at visualizing (grasping) the physical or biological phenomena through interfaces and / or installations designed specifically for such purpose. Such works often mirror the post-­digital condition of our time where the digital technologies constitute the common background for everyday activities, no longer having the allure of "new" and "exciting" (Berry, Dieter et al., 2015). In this process, both the networked technologies of wireless communication and the act of crossing the boundaries between the digital and the physical play the crucial role as the post-­digital networked imagery increasingly becomes directly connected to the physical environment. I would like to ponder on the questions of processuality and relationality involved in such instances where the complexity of the hybrid works of art clearly transgresses the paradigm of representationalism (Thrift, 2008;; Anderson and Harrison, 2010;; Kember and Zylinska, 2012). The particular attention is given to the fact that such artworks bond different ontological realms (discursive, physical, digital) and different agents (human and non-­human, carbon-­based and software-­based) forging “ontological coalitions” (Malafouris, 2013). Throughout the article the mutlirealist and relational perspective is offered, inspired by the propositions of Gilbert Simondon and Etienne Souriau. Based on the research project supported by National Science Centre Poland ("The aesthetics of post-­digital imagery: between new materialism and object-­oriented philosophy", 2016/21/B/HS2/00746)

    Adaptative Potential of the Lactococcus Lactis IL594 Strain Encoded in Its 7 Plasmids

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    The extrachromosomal gene pool plays a significant role both in evolution and in the environmental adaptation of bacteria. The L. lactis subsp. lactis IL594 strain contains seven plasmids, named pIL1 to pIL7, and is the parental strain of the plasmid-free L. lactis IL1403, which is one of the best characterized lactococcal strains of LAB. Complete nucleotide sequences of pIL1 (6,382 bp), pIL2 (8,277 bp), pIL3 (19,244 bp), pIL4 (48,979), pIL5 (23,395), pIL6 (28,435 bp) and pIL7 (28,546) were established and deposited in the generally accessible database (GeneBank). Nine highly homologous repB-containing replicons, belonging to the lactococcal theta-type replicons, have been identified on the seven plasmids. Moreover, a putative region involved in conjugative plasmid mobilization was found on four plasmids, through identification of the presence of mob genes and/or oriT sequences. Detailed bioinformatic analysis of the plasmid nucleotide sequences provided new insight into the repertoire of plasmid-encoded functions in L. lactis, and indicated that plasmid genes from IL594 strain can be important for L. lactis adaptation to specific environmental conditions (e.g. genes coding for proteins involved in DNA repair or cold shock response) as well as for technological processes (e.g. genes encoding citrate and lactose utilization, oligopeptide transport, restriction-modification system). Moreover, global gene analysis indicated cooperation between plasmid- and chromosome-encoded metabolic pathways

    Biodegradable fixation plates for veterinary medicine

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    Niniejsza praca stanowi próbę opracowania nowych biowchłanialnych płytek zespalających dla potrzeb weterynarii dedykowanych szczególnie psom ras miniaturowych. Tego typu płytki mogą stanowić alternatywę dla implantów metalicznych. Do największych zalet proponowanych konstrukcji można zaliczyć brak konieczności usuwania ich z organizmu po wyleczeniu złamanej kości oraz ułatwioną, w porównaniu do implantów metalicznych, ocenę radiologiczną procesu gojenia ze względu na przepuszczalność zastosowanego materiału dla promieni X. Ograniczeniem stosowania płytek wykonanych z czystych polimerów resorbowalnych np. polilaktydu (PLA) są stosunkowo słabe właściwości mechaniczne. W związku z tym, w ramach poniższej pracy, zaproponowano cztery sposoby modyfikacji parametrów wytrzymałościowych i użytkowych czystego polimeru resorbowalnego. Do matrycy polimerowej z czystego PLA wprowadzono cztery rodzaje wzmocnienia: włókna węglowe, włókna poliakrylonitrylowe, drut ze stali chirurgicznej i drut magnezowy. Płytki proste sześciootworowe wykonano metodą wtrysku. Fazę wzmacniającą w postaci włókien lub drutu formowano w kształt odpowiadający obrysowi zewnętrznemu płytki. Tak przygotowane pętle umieszczano w formie wtryskowej, a następnie obtryskiwano ciśnieniowo polimerem w temp. 165-170°C. Gotowe płytki zespalające poddano badaniom wytrzymałościowym. W tym celu przygotowano krótkie drewniane wałki, do których metalowymi wkrętami przykręcano płytki (dwa wałki imitujące złamaną kość łączono jedną płytką). Następnie taki układ symulujący zespolenie kostne poddawano testom jednoosiowego rozciągania na maszynie wytrzymałościowej. Równocześnie przeprowadzono badania in vitro w środowisku wodnym. Określono zmiany pH, przewodności elektrycznej oraz zmiany masy i wytrzymałości po 6 tygodniowej inkubacji. Spośród badanych materiałów najlepsze właściwości mechaniczne uzyskano w przypadku modyfikacji polimeru fazą włóknistą. Dodatkowo wprowadzenie włókien pozwoliło uzyskać korzystniejszy rozkład naprężeń i odkształceń w obrębie otworów mocujących oraz wynikający z tego efektywniejszy sposób przenoszenia obciążeń podczas jednoosiowego rozciągania.This article is an attempt to develop a new concept of biodegradable fixating miniplates for veterinary medicine, specially for toy breed dogs. Polymer-based composite fixation system can be a good alternative for widely used metallic implants because there is no removal operation needed after the bone is recovered. Moreover, the radiological evaluation of a fracture healing process is much easier and more precise due to the fact that polymers are transparent for X-rays. Low mechanical properties of pure biodegradable polymers e.g.: polylactide (PLA) is one of the biggest drawbacks. For the development of implants with better mechanical and practical properties (compared to pure polymer PLA) four types of composite materials were proposed. Polylactide matrix was reinforced with: carbon fibres, polyacrylonitrile fibres, surgical steel wire and magnesium wire. Injection moulding process was applied to fabricate a six-hole I-shaped miniplates. Firstly, reinforcing phases (fibres or wires) were shaped to copy a contour of a miniplate. Then a “loop” of a fibre bundle or a wire was placed in the mould. Plastified PLA (T = 165-170°C) was injected into the mould under a high pressure filling it and covering reinforcing phase. For mechanical testing of fabricated implants a special system was prepared to simulate “real work conditions”. Short wooden rods were used to imitate the broken bone. Two rods were linked together with a composite miniplate fixed with metallic screws and tested in uniaxial tensile strength machine. Simultaneously in vitro tests were carried out. Degradation in water environment was verified. During six-weeks incubation process changes in pH values, electrical conductivity, mass loss and mechanical properties were monitored. The performed research demonstrated that the most desirable results were recorded for the polymer modified with the fibrous phase

    Evaluation of repair of osteochondral defects in rabbits using new composite biomaterials during three-month observation

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    In this work nanocomposite porous pins were implanted into rabbit knees. The pins were made of biodegradable synthetic poly-L/DL-lactide (80:20) which was modified with nanometric hydroksyapatite particles (HAp) and covered with biopolymer layer of sodium alginate (NA). In vivo experiments were conducted on a 4-element group of the New Zealand rabbits. Osteogenesis was observed using scanning electron microscope (SEM/EDS) after 12 weeks of implantation

    Evaluation of repair of osteochondral defects in rabbits using new composite biomaterials during three-month observation

    No full text
    In this work nanocomposite porous pins were implanted into rabbit knees. The pins were made of biodegradable synthetic poly-L/DL-lactide (80:20) which was modified with nanometric hydroksyapatite particles (HAp) and covered with biopolymer layer of sodium alginate (NA). In vivo experiments were conducted on a 4-element group of the New Zealand rabbits. Osteogenesis was observed using scanning electron microscope (SEM/EDS) after 12 weeks of implantation
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