203 research outputs found
Muon cooling: Longitudinal compression
No full textA 10 MeV/c positive muon beam was stopped in helium gas of a few mbar in a magnetic field of 5 T. The muon "swarm" has been efficiently compressed from a length of 16 cm down to a few mm along the magnetic field axis (longitudinal compression) using electrostatic fields. The simulation reproduces the low energy interactions of slow muons in helium gas. Phase space compression occurs on the order of microseconds, compatible with the muon lifetime of 2 mu s. This paves the way for the preparation of a high-quality low-energy muon beam, with an increase in phase space density relative to a standard surface muon beam of 10(7). The achievable phase space compression by using only the longitudinal stage presented here is of the order of 10(4)
muCool: a next step towards efficient muon beam compression
No full textA novel device to compress the phase space of a muon beam by a factor of with a efficiency is under development. A surface muon beam is stopped in a helium gas target consisting of several compression stages, wherein strong electric and magnetic fields are applied. The spatial extent of the stopped muon swarm is decreased by means of these fields until muons with eV energy are extracted into vacuum through a small orifice. It was observed that a 20 cm long muon stop distribution can be compressed in the longitudinal direction to a sub-mm extent within 2~\upmu \hbox {s}. Additionally, a drift perpendicular to the magnetic field of the compressed low-energy muon swarm was successfully demonstrated, paving the way towards extraction from the gas and re-acceleration of the muons
Teoria agresji Darwina według Freuda i chrześcijańska miłość bliźniego. Die Aggressionstheorie Darwins nach Freud und die christliche Nachstenliebe.
No full textAccording to Charles Darwin\u27s theory of evolution, aggression is an indispensable factor of development, since the stronger eliminates the weaker. This behavior works on the plane of lower living beings and proceeds through environmentally conditioned selection. In the case of beings driven by instinct, human beings included, such a selection is effected by means of aggression. The theory has moral implications and they are the focus of the present paper. The author discusses the practical implementations of this theory in "the age wolves", as he calls the time of Hitler\u27s and Stalin\u27s dictatorships, and also in the "futuristic manifesto" - the aftermath of the French Revolution, as well as in the framework of Freud\u27s psychoanalysis, where one of the basic thesis claims that renouncement of the sexual drive leads to aggression. According to the author such beliefs are relevant to the contemporary phenomena of robotics, genetic technology and nanotechnology. The author enters into polemics with those beliefs by referring to the basic contents of the Christian faith, mainly to the perspective of the love of neighbor.Zgodnie z teorią ewolucji Ch. Darwina, agresja stanowi niezbędny faktor rozwoju, gdyż silniejszy eliminuje słabszego. Dzieje się to na płaszczyźnie niższych istot żywych na drodze selekcji uwarunkowanej środowiskiem. W przypadku istot kierujących się instynktem, w tym także u człowieka, dokonuje się to na drodze agresji. Teoria ta ma swoje implikacje moralne, co jest przedmiotem niniejszego artykułu. Autor omawia w nim zarówno praktyczne zastosowanie założeń tej teorii w ,,wieku wilków", jak nazywa czas dyktatur hitlerowskiej i stalinowskiej, ale także w ,,futurystycznym manifeście" będącym pokłosiem Rewolucji Francuskiej czy w ramach psychoanalizy Z. Freuda, którego jedna z podstawowych tez głosi, że rezygnacja z popędu prowadzi do agresji. W przekonaniu autora, z przekonaniami tymi wiążą się współczesne zjawiska robotyki, techniki genetycznej i nanotechnologii. Z tymi poglądami autor polemizuje, odwołując się do podstawowych treści wiary chrześcijańskiej, głównie zaś do perspektywy miłości bliźniego
Functional characterisation of neurovascular components in physiological and pathological conditions
No full textPericytes, which are embedded in the basement membrane of the capillary wall, play important roles in many processes in the brain including blood brain barrier maintenance and angiogenesis. However, there is considerable confusion about the role of pericytes in blood flow regulation due to the lack of a uniform pericyte definition. Increased knowledge of pericyte function will be critical for further understanding of their role in neurovascular coupling and diseases. The aim of this thesis was to identify signalling mechanisms of human brain pericytes since so far the majority of studies described pericytes from other organs and species. In addition, in vivo two-photon imaging of the mouse brain was to be established to study the cells in their native environment. Calcium imaging and patch-clamping were applied to functionally characterise the cells regarding Ca2+ dynamics and electrophysiological properties. The expression pattern of various cell-specific markers, G protein-coupled receptors (GPCRs) and ion channels was measured via RNA-sequencing. Finally, in vivo two-photon imaging was used to visualise pericytes in the mouse brain. The cells responded to GPCR agonists that are known to raise Ca2+ in pericytes with a variety of Ca2+ dynamics. Furthermore, we establish the expression and function of GPCR agonists that have not been linked to pericytes before. The patch-clamp experiments revealed the resting membrane potential, resistance and capacitance of human brain pericytes. The cells expressed a limited number of ion channels conducting small currents, but they seem to play a role in the intracellular Ca2+ signalling cascade. The lack of response to a number of well-established agonists made us sceptical about the identity of the human CNS pericytes. The transcriptomic analysis revealed their real identity and the expression of yet untested GPCRs and ion channels. Finally, different pericyte labelling techniques were established to investigate the location and morphology of pericytes in the mouse brain. Overall, this work contributes to our understanding of Ca2+ signalling dynamics and electrophysiological properties of human vascular cells. We provide evidence that the human CNS pericytes used in this thesis are likely a different vascular-associated cell type, which was recently found in the mouse brain. Lastly, the in vivo imaging technique builds the basis for future studies in the lab investigating the mouse brain microvasculature in health and disease
Reliability exercise for the polymyalgia rheumatica classification criteria study : the Oranjewoud ultrasound substudy
No full textObjective. A study supported by the EULAR and the ACR being conducted to establish classification criteria for polymyalgia rheumatica (PMR) will include ultrasound examination of the shoulders and hips. Ultrasound (US) depicts glenohumeral joint effusion, biceps tenosynovitis, subdeltoid bursitis, hip joint synovitis, and trochanteric bursitis in PMR. These findings may aid in distinguishing PMR from other diseases. The purpose of this study was to assess standards and US interreader agreement of participants in the PMR classification criteria study. Methods. Sixteen physicians in four groups examined shoulders and hips of 4 patients and 4 healthy adults with ultrasound. Overall agreement and interobserver agreement were calculated. Results. The overall agreement (OA) between groups was 87%. The OA for healthy shoulders was 88.8%, for healthy hips 100%, for shoulders with pathology 85.2%, and 74.3% for hips with pathology, respectively. Conclusion. There was a high degree of agreement found for the examination of healthy shoulders and pathologic hips. Agreement was moderate for pathologic shoulders and perfect for healthy hips. US of shoulder and hips performed by different examiners is a reliable and feasible tool for assessment of PMR related disease pathology and can be incorporated into a classification criteria study
A Ramsey apparatus for proton spins in flowing water
No full textWe present an apparatus that applies Ramsey's method of separated oscillatory
fields to proton spins in water molecules. The setup consists of a water
circuit, a spin polarizer, a magnetically shielded interaction region with
various radio frequency elements, and a nuclear magnetic resonance system to
measure the spin polarization. We show that this apparatus can be used for Rabi
resonance measurements and to investigate magnetic and pseudomagnetic field
effects in Ramsey-type precision measurements with a sensitivity below 100 pT
Market entry of an innovative technology : the example of a new app on the brazilian tourism market
No full textThe Brazilian start-up Local Wander plans to enter the tourism sector with a mobile application aiming to enable a new form of travel research. A web-based survey has been sent out to the start-up’s target audience (n: 236) in order to gain further relevant information for the designing of Local Wander’s market entry strategy. By applying the diffusion of innovation theory, this thesis could detect five different adopter categories, originally described by Rogers (1962), among Local Wander’s target audience based on their adoption intention. The Early Market was observed to be significantly bigger than the theory predicted. Research revealed four char-acteristics to be of significant impact on the adoption intention: Relative Perceived Product Advantage, Perceived Product Complexity, Compatibility with digital travel research sources, and the adopter’s Innovativeness towards mobile applications. Specific characteristics in order to identify Local Wander’s early users, the so called Innovators, were detected giving indica-tions for further necessary company market research. Findings showed that the diffusion of innovation framework is a helpful tool for start-ups’ prospective decision making and market entry strategy planning.A Start-up Brasileira Local Wander planeja entrar no setor de turismo através de um aplicativo para telefone celular, com o objetivo de oferecer um novo serviço de pesquisa para viajantes. Uma pesquisa, via internet, foi enviada a 236 pessoas identificadas como público-alvo para a Start-up a fim de obter mais informações relevantes para a criação da estratégia de entrada no mercado. Ao aplicar a teoria da difusão da inovação, esta dissertação pôde identificar cinco diferentes categorias de adotantes, como descrito originalmente por Rogers (1962), entre o pú-blico-alvo da Local Wander com base na sua intenção de adoção. O Mercado Inicial foi obser-vado significativamente maior do que a teoria previu. A pesquisa, acima citada, revelou quatro características de forte impacto sobre a intenção de adoção do produto: Vantagem relativa do produto percebida pelo público-alvo, complexidade percebida, compatibilidade com recursos digitais de pesquisa de viagem e o quão inovador são os adotantes em relação aos aplicativos para celular. Características específicas para identificar os primeiros usuários do Local Wander, chamados de inovadores, foram detectados dando indicações para futuras pesquisas que sejam necessárias para a empresa. Os resultados encontrados mostram que a teoria da difusão da ino-vação é uma ferramenta extremamente útil para a tomada de decisão em Start-ups e para o desenvolvimento de estratégia para entrada no mercado
Market entry of an innovative technology: the example of a new app on the Brazilian tourism market
No full textThe Brazilian start-up Local Wander plans to enter the tourism sector with a mobile application aiming to enable a new form of travel research. A web-based survey has been sent out to the start-up’s target audience (n: 236) in order to gain further relevant information for the designing of Local Wander’s market entry strategy. By applying the diffusion of innovation theory, this thesis could detect five different adopter categories, originally described by Rogers (1962), among Local Wander’s target audience based on their adoption intention. The Early Market was observed to be significantly bigger than the theory predicted. Research revealed four characteristics to be of significant impact on the adoption intention: Relative Perceived Product Advantage, Perceived Product Complexity, Compatibility with digital travel research sources, and the adopter’s Innovativeness towards mobile applications. Specific characteristics in order to identify Local Wander’s early users, the so called Innovators, were detected giving indications for further necessary company market research. Findings showed that the diffusion of innovation framework is a helpful tool for start-ups’ prospective decision making and market entry strategy planning.A Start-up Brasileira Local Wander planeja entrar no setor de turismo através de um aplicativo para telefone celular, com o objetivo de oferecer um novo serviço de pesquisa para viajantes. Uma pesquisa, via internet, foi enviada a 236 pessoas identificadas como público-alvo para a Start-up a fim de obter mais informações relevantes para a criação da estratégia de entrada no mercado. Ao aplicar a teoria da difusão da inovação, esta dissertação pôde identificar cinco diferentes categorias de adotantes, como descrito originalmente por Rogers (1962), entre o pú- blico-alvo da Local Wander com base na sua intenção de adoção. O Mercado Inicial foi observado significativamente maior do que a teoria previu. A pesquisa, acima citada, revelou quatro características de forte impacto sobre a intenção de adoção do produto: Vantagem relativa do produto percebida pelo público-alvo, complexidade percebida, compatibilidade com recursos digitais de pesquisa de viagem e o quão inovador são os adotantes em relação aos aplicativos para celular. Características específicas para identificar os primeiros usuários do Local Wander, chamados de inovadores, foram detectados dando indicações para futuras pesquisas que sejam necessárias para a empresa. Os resultados encontrados mostram que a teoria da difusão da inovação é uma ferramenta extremamente útil para a tomada de decisão em Start-ups e para o desenvolvimento de estratégia para entrada no mercado
Remény és félelem
No full textHope and fearNorbert SzanyiAccording to Joachim Piegsa hope and fear are connected strongly to one another. Through them we can strengthen or even lose our courage for life. Hope is the way we relate to our future: through hope we envision a future, where our desires become real. Hope helps us to cope with the difficulties of life
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