524 research outputs found
Molecular and Cellular Analysis of the Nematostella vectensis Cnidom
Cnidaria is the sister group of Bilateria and thus phylogenetically at the base of the Metazoa. The characteristic trait of the phylum is the presence of nematocysts or cnidae. These unique extrusive organelles are used for prey capture, feeding, defense and partly locomotion. Cnidae or nematocysts consist of a capsule wall, a tubule with or without spines, and an opercular structure. They are produced in specialized cells (nematocytes) as secretory products in a giant post-Golgi vesicle. These stinging organelles can resist extremely high pressure and their discharge is one of the fastest mechanisms in animal kingdom. In the last decade the sea anemone Nematostella vectensis (Anthozoa) became an emerging model organism alongside Hydra (Hydrozoa) for developmental and evolutionary biology. Nevertheless basic data on histology and the nematocyst repertoire (cnidom) of Nematostella vectensis are still missing. In my thesis, I characterized the Nematostella vectensis cnidom based on morphological classification. For that matter an isolation technique for intact capsules was established and the different nematocysts were analyzed using electron and light microscopy. The three capsule types (basitrichous haplonema, microbasic mastigophores and spirocysts) were quantitatively analyzed along the body axis and in the different developmental stages. Besides the morphological characterization, three molecular capsule components, minicollagen 1, 3 and 4 were isolated and in situ hybridization was performed to see their expression patterns. Antibody stainings revealed a partly abundant and partly nematocyst specific patterns of the minicollagens. The second part of the work was focused on the cellular identification of nematocysts in Nematostella vectensis. Thus, all cell types were characterized qualitatively and a cell cycle analysis was performed. Nematocytes were identified to be cuboidal epithelial cells using antibody stainings on macerates. Hence, the nematocysts in Nematostella vectensis have an epithelial origin and not as in Hydra a neuronal
Über Wahrheit und Lüge im politischen Sinn. Arendts Konzept der Meinungsbildung
Arendts Essay irritiert in Zeiten von Fake-News mit der These, dass der Anspruch aufWahrheit im Kontext der Politik abzuweisen sei. In der Tat leistet Arendt mit ihren Überlegungen einen Beitrag zur fälligen Rehabilitierung der Meinungen in ihrer praktischen, handlungsleitenden Funktion gerade durch die Abgrenzung von Meinungen gegenüber dem in politischen Verhältnissen unangemessen Anspruch auf unbedingte Wahrheit. Im Horizont von Meinungen erschließen sich die Möglichkeiten des Handelns. Vernunftwahrheiten erweisen sich dagegen auf dem Feld des Politischen, das sich für Arendt durch den Pluralismus der Meinungen konstituiert, als tyrannisch.Aus dieser Perspektive ergibt sich eine analytisch schärfere Diagnose der politischen Lüge, als es die auf Moral abgestellten Invektiven zu leisten vermögen. Lüge unterminiert,für alle Beteiligten, die Orientierungsfunktion der öffentlichen Meinung.Arendt's essay irritates in times of fake news with the thesis that the claim to truth in the context of politics must be rejected. In fact, Arendt's reflections contribute to the due rehabilitation of opinions in their practical, action-guiding function precisely through the differentiation of opinions from the claim to absolute truth that is inappropriate in political circumstances. In the horizon of opinions the possibilities of action open up. In contrast, truths of reason prove to be tyrannical in the field of the political, which for Arendt is constituted by the pluralism of opinions.From this perspective, an analytically sharper diagnosis of the political lie emerges than the invectives based on morality can provide. Lies undermine, for all participants, the orientation function of public opinion
The effect of beam curvature on bending properties of sandwich structures
Sandwich composites are well known for many years and its place among the construction materials have they deserved mainly due to very good mechanical properties related to their weight. These materials have been a subject for many researches, but very few of them were focused on the behavior of curved constructions in bend with respect to their specific shape (curvature). With increasing number of new materials and resulting possible material combinations, it is necessary to characterize performance of new prepared structures and also evaluate the effect of a shape on the behavior of sandwich constructions with regard to their material composition. Presented paper deals with an investigation of flat and curved beams of sandwich structures, which correspond by their material composition to those, used in transport industry. Specifically, the influence of curvature size on a change of bending properties of structures with specific material composition compared to flat constructions is evaluated. This influence is also investigated in terms of specimen clamping and type of bending test. Obtained results showed that properties of sandwich structures are dependent not only on size of curvature, bud also on core thickness. Moreover, these results can help designers, constructers or technologists with design, dimensioning or production of these materials for specific applications. © 2016. Published by Manufacturing Technology
Ett grönt möte mellan eklandskapet och en ny stadsdel i Linköping
The purpose of this essay is to analyze and show possibilities how a city can grow into the scenery of a oak dominated landscape and how this encounter can add values to the city.
The city in focus is Linköping, a city that is approaching one of Sweden's largest oak dominated cultural landscapes. To this landscape high ecological and cultural values are connected. The recreational values are also of importance especially because of its urban location also because the city is mainly surrounded by flat agricultural land.
Djurgården is the district that is going to be established in the fringe of the oak landscape. In the comprehensive plan the municipality gives guidelines for the structure of this new urban area. Some of the analyzes in this essay starts from this proposed plan. The aim for this work is not to give a absolute solution, but more to give inspirations and ideas for the encounter between the city of Linköping and the oak dominated landscape.
The focus of the work is to define characteristics of the landscape, qualities that could be valuable in a city.
Climate changes and increased frequency of natural disasters shows the importance of our respect and adjustment to the nature. The protection of nature is encouraged when nature becomes a part of our everyday life, when we give nature a place in our consciousness.
The landscape show different characters as wooded meadow, broadleaf forest and pasture land. The different environments all have in common the openness and light with a rich fauna and flora. This kind of environments demands grazing or cultivation to last.
Djurgården is a part of the oak landscape, a landscape that shows a pattern of islands arising above flat agricultural field surface. The islands are overgrown with vegetation dominated by oak trees.
This essay shows how a framework of a green city web could be achieved when these islands are tied together into paths and connect to existing urban green areas. A web that let the cultural landscape spread in between the blocks of the city. The web strengthens the biological values and the accessibility out in the landscape. The surrounding landscape become a part of the future Djurgården when integrate urban functions with the pattern of the oak landscape. Urban places in our everyday life could be designed with characters and values that is connected and interplays with the oak landscape. The visual contact between the places is of great importance, otherwise they will become isolated and no part of the matrix.
"The deferens between living in the countryside and in the city is that there are living animals in the countryside, but in the city people are living." Translated from the book Gamla tanter lägger inte ägg, (Levengood, 2003).
Maybe the difference between the city and the nature doesn't need to be so dramatically. Djurgården has the opportunity to demonstrate a city plan where the connection to the surrounding landscape is noticeable and taken care of also inside the area.Syftet med detta examensarbete är att analysera och
visualisera möjligheter för hur en stad kan växa ut
mot och möta ett eklandskap och hur landskapet kan
tillföra positiva värden i staden.
Staden ifråga är Linköping som närmar sig ett
möte med ett av landets största sammanhängande
ekdominerade odlingslandskap. Till detta landskap är
stora biologiska och kulturella värden knutet. Även
ur rekreationssynpunkt är området mycket viktigt
framförallt med hänsyn till det stadsnära läget och att
staden i övrigt till stora delar omges av östgötaslättens
storskaliga jordbrukslandskap.
I översiktplan och områdesprogram har kommunen
tagit fram riktlinjer och övergripande struktur för
Djurgården, den stadsdel som ska etableras i en del av
eklandskapet. Delar av examensarbetets analyser sker
med utgångspunkt från denna plan. Avsikten med
arbete är inte att komma med färdiga lösningar utan
snarare att ge inspiration och idéer med principiella
förslag på mötet mellan eklandskapet och Linköping.
Tyngdpunkten i mitt arbete ligger i att definiera
eklandskapets egenskaper. Karaktärer och kvalitéer
som kan användas och fortleva i staden.
Klimatförändringar och en ökad frekvens av
naturkatastrofer visar att vi måste ta hänsyn till och
anpassa oss till naturen. Skyddet av naturen stärks när
vi knyter naturen till vår vardagliga livsmiljö och ger
den en plats i vårt medvetande.
Eklandskapet visar upp flera karaktärer och mönster
med ängar, lövskogar och betesmarker, gemensamt
för dem är att de är ljusa miljöer med en rik flora och
fauna och att de kräver hävd för att bestå.
Arbetets utmaning blev att visa på hur man
övergripande kan låta eklandskapet flyta in i staden
och uppnå en samhörighet. Metoden var att använda
mig av landskapsekologins rumsliga strukturer och
binda samman Djurgårdens spridda värdekärnor
till stråk. Stråken ansluter till grönytor i staden och
skapar stommen till en grön stadsväv. En väv som
stärker biologisk mångfald och tillgänglighet ut i
landskapet. I Djurgårdens framtida stadskvarter knyts
det omgivande landskapet till de boende genom att
integrera stadens funktioner med eklandskapets ömönster.
Urbana samlingsplatser som används i vår
vardag utformas med tydlig karaktär och kvaliteter
som signalerar en tillhörighet och ett samspel
med eklandskapet. Den visuella kontakten mellan
miljöerna är en nyckel till att platserna inte upplevs
som isolerade element utan ingår i en helhet.
”Skillnaden mellan att bo på landet och i stan är att man har
levande djur på landet. Men i stan är människorna levande”
Ole 6 år , citat ur boken Gamla tanter lägger inte ägg
(Levengood, 2003).
Kanske behöver inte skillnaden mellan stad och
land vara så dramatisk. Djurgården har möjligheten
att uppvisa en stadsplanering där samhörigheten till
omgivande landskapet speglas även inne i området
Сравнительная клинико-гормональная характеристика состояния здоровья и качество жизни женщин с хирургической и естественной менопаузой
ГОРМОНЫДЕПРЕССИЯЖЕНЩИНЫКАЧЕСТВО ЖИЗНИМЕНОПАУЗАПОСТМЕНОПАУЗ
Multifunctional Carbon Fiber Composites: A Structural, Energy Harvesting, Strain-Sensing Material
Multifunctional structural materials are capable of reducing system level mass and increasing efficiency in load carrying structures. Materials that are capable of harvesting energy from the surrounding environment are advantageous for autonomous electrically powered systems. However, most energy harvesting materials are non-structural and add parasitic mass, reducing structural efficiency. Here, we show a structural energy harvesting composite material consisting of two carbon fiber (CF) layers embedded in a structural battery electrolyte (SBE) with a longitudinal modulus of 100 GPa-almost on par with commercial CF pre-pregs. Energy is harvested through mechanical deformations using the piezo-electrochemical transducer (PECT) effect in lithiated CFs. The PECT effect creates a voltage difference between the two CF layers, driving a current when deformed. A specific power output of 18 nW/g is achieved. The PECT effect in the lithiated CFs is observed in tension and compression and can be used for strain sensing, enabling structural health monitoring with low added mass. The same material has previously been shown capable of shape morphing. The two additional functionalities presented here result in a material capable of four functions, further demonstrating the diverse possibilities for CF/SBE composites in multifunctional applications in the future
Conceptual design framework for laminated structural battery composites
The structural battery composite is a class of composite materials with ability to provide mechanical integrity in a structural system while simultaneously store electrical energy (i.e. work as a battery). In this paper a framework to estimate the mechanical and electrical performance of laminated structural battery composites is proposed. The mechanical performance of the battery composite laminate is assessed by estimating the in-plane elastic properties of the laminate using Classical Laminate Theory. The electrical performance is assessed estimating the specific capacity and energy density of the component. The developed framework is applied on an A4 sized structural battery composite demonstrator, as part of the Clean Sky 2 project SORCERER [1] to demonstrate the capabilities of the framework. The design process for the demonstrator is presented and mechanical and electrical performance metrics are estimated for three laminate configurations, one promoting structural performance, one promoting electrical performance and one intermediate. As the material provides both load carrying and electrical energy storage capabilities, the laminate configuration can be alternated to provide suitable performance based on the purpose of the component
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