12 research outputs found
Hierarchical multiple peeling simulations
No full textThe phenomenon of the exceptional dry adhesion achieved by some natural biological materials has been widely investigated in recent years. In particular, the analysis of the terminal elements of gecko pads and their specific structure and topology has led to the development of bioinspired synthetic fibrillar adhesives, including mushroom-shaped tips. To model the expected adhesion and detachment behaviour of multiple contacts, only recently the last author has derived a theory of multiple peeling, extending the pioneering energy-based single peeling theory of Kendall, including large deformations and pre-stretching. In this contribution, we study the problem of the adhesion of single and multiple contacts using finite element analysis, with the aim of studying complex peeling geometries. Both non-hierarchical tape-like and hierarchical geometries are considered, and the adhesive properties are compared, showing a marked improvement in the latter case. Results are promising and the numerical approach can be exploited in future attempts to determine optimal configurations and improve the adhesion of artificial bioinspired structures
Emerging topics in nanophononics and elastic, acoustic, and mechanical metamaterials: an overview
No full textThis broad review summarizes recent advances and "hot"research topics in nanophononics and elastic, acoustic, and mechanical metamaterials based on results presented by the authors at the EUROMECH 610 Colloquium held on April 25-27, 2022 in Benicássim, Spain. The key goal of the colloquium was to highlight important developments in these areas, particularly new results that emerged during the last two years. This work thus presents a "snapshot"of the state-of-the-art of different nanophononics- and metamaterial-related topics rather than a historical view on these subjects, in contrast to a conventional review article. The introduction of basic definitions for each topic is followed by an outline of design strategies for the media under consideration, recently developed analysis and implementation techniques, and discussions of current challenges and promising applications. This review, while not comprehensive, will be helpful especially for early-career researchers, among others, as it offers a broad view of the current state-of-the-art and highlights some unique and flourishing research in the mentioned fields, providing insight into multiple exciting research directions. Computational Design and MechanicsBiomaterials & Tissue Biomechanic
„Cywilizacja? Puste słowo”. Antycywilizacjonizm w polskim podróżopisarstwie międzywojennym
No full textThe article discusses the criticism of civilization presented in the interwar travel literature. The author points out that the critical attitude towards European civilization is directly related to the modernist paradigm. Interwar writers-travellers express their views using existing rhetorical figures, treating the modern city as a metonymy of civilization. Therefore, they use simple contrasts, such as culture-nature, disease-health, old age-youth, dirt-cleanliness, etc. They seek escape from civilization on
the city outskirts or in places perceived as exotic. Tadeusz Dębicki and Kazimierz Nowak combine anti-civilization attitudes with anti-colonial views, unlike Ferdynand Ossendowski, who, while critical of the situation in Europe, simultaneously expresses his enthusiasm for the actions of the [email protected]ł Filologii Polskiej i Klasycznej, Uniwersytet im. Adama Mickiewicza w PoznaniuBalawelder Romuald (1939), Bug zaprasza na przygody, Warszawa: Księgarnia W. Michalak.Cembrzyńska Patrycja (2012), Wieża Babel. Nowoczesny projekt porządkowania świata i jego dekonstrukcja, Kraków: Universitas.Ciechanowiecka Ludwika (1933), W sercu Sahary. Algier – Mzab – Tidikelt – Hoggar, Warszawa: Wydawnictwo Księgarni Szylinga.Dębicki Tadeusz (2016), Moienzi Nzadi. U wrót Konga, wstęp: O. Stanisławska, wyd. 2, Warszawa: Wydawnictwo Dowody na Istnienie.Fik Ignacy (1939), 20 lat literatury polskiej (1918–1938), Kraków: Spółdzielnia Wydawnicza „Czytelnik".Gazda Grzegorz (1972), Funkcja prymitywizmu i egzotyki w literaturze międzywojennej, w: Problemy literatury polskiej lat 1890–1939. Seria 1., red. H. Kirchner, Z. Żabicki,
M.R. Pragłowska, Wrocław: Zakład Narodowy im. Ossolińskich, s. 365–394.Glensk Urszula (2018), Historia słabych. Reportaż i życie w Dwudziestoleciu (1918–1939), Kraków: Universitas.Głowiński Michał (1990), Labirynt, przestrzeń obcości, w: M. Głowiński, Mity przebrane, Kraków: Wydawnictwo Literackie, s. 129–216.Grądzka Natalia (2009), Wokół Kazimierza Nowaka. Od podróży po koloniach do postkolonizowania Polski, „Panoptikum”, nr 8, s. 221–234.Juszkiewicz Piotr (2022), Utopia sprawczości, w: Nowy początek. Modernizm w II RP, red. P. Juszkiewicz, A. Szczerski, Kraków: Muzeum Narodowe w Krakowie, s. 39–62.Kopeć Zbigniew (2021), Ferdynanda Antoniego Ossendowskiego (niektóre) przypadki, w: Zapisane. Reportaż międzywojenny interpretowany przez pisarzy i historyków literatury, red. U. Glensk, I. Grin, Kraków: EMG, s. 237–250.Koss Tadeusz (1933), Pieszo przez pustynię. Wrażenia z wycieczki po Tunisji, Warszawa: Księgarnia Wydawnicza „Polska Zjednoczona”.Kowalski Marek Arpad (2010), Dyskurs kolonialny w Drugiej Rzeczypospolitej, Warszawa: Wydawnictwo DiG.Kowalewscy Anna i Tadeusz (1937), Nasza eskapada po Pilicy. Reportaż z włóczęgi kajakowej, Warszawa: : Gebethner i Wolff.Ligęza Wojciech (1998), Jerozolima i Babilon. Miasta poetów emigracyjnych, Kraków: Wydawnictwo Baran i Suszczyński.MacCannell Dean (2005), Turysta. Nowa teoria klasy próżniaczej, przeł. E. Klekot, A. Wieczorkiewicz, Warszawa: Warszawskie Wydawnictwo Literackie MUZA.Marcinkowski Adam (1937), Od Dźwiny po Dniestr, Wilno: nakładem autora.Michałowski Witold (2004), Wielkie safari Antoniego O. Kim był Antoni Ferdynand Ossendowski, Warszawa: Wydawnictwo Iskry.Miłaszewska Wanda (1931), Czarna Hańcza, Poznań: Księgarnia św. Wojciecha.Nowacki Marek (2010), Autentyczność atrakcji a autentyczność doświadczeń turystycznych, „Folia Turistica”, nr 23, s. 7–21.Nowak Kazimierz (2008), Rowerem i pieszo przez Czarny Ląd. Listy z podróży afrykańskiej z lat 1931–1936, wyd. 3. rozsz., oprac. Ł. Wierzbicki, Poznań: Sorus.Ossendowski Ferdynand Antoni (1926), Czarny czarownik. Relacja z wyprawy do Afryki 1926 r., Warszawa: Towarzystwo Wydawnicze „Rój”.Ossendowski Ferdynand Antoni (1927), Wśród czarnych, Lwów–Warszawa–Kraków: Zakład Narodowy im. Ossolińskich.Paczkowski Mikołaj (2018), Poetyka antykolonialna w reportażu Tadeusza Dębickiego „Moienzi Nzadi. U wrót Konga”, „Forum Poetyki”, nr 11–12, s. 128–135.Podhorska-Okołów Maria (1935), Kajakiem z Warszawy, Warszawa: Główna Księgarnia Wojskowa.Rowiński Cezary (2011), Rozważania na temat egzotyzmu w literaturze, w: Orient w litera turze i kulturze modernizmu, red. E. Łoch, Lublin: Wydawnictwo UMCS, s. 93–100.Rybicka Elżbieta (2003), Modernizowanie miasta. Zarys problematyki urbanistycznej w najnowszej literaturze polskiej, Kraków: Universitas.Salvadori Roberto (2004), Mitologia nowoczesności, przeł. H. Kralowa, Warszawa: Fundacja Zeszytów Literackich.Sienkiewicz Barbara (2002), Miasto Przybosia (w poezji międzywojnia), w: Stulecie Przy bosia, red. S. Balbus, E. Balcerzan, Poznań: Wydawnictwo Naukowe UAM,
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Exploring the Role of Topoisomerase II Beta in Macrophage Maturation and Pro-inflammatory Cytokine Production
No full textAlthough it is known that DNA topo IIβis required for the regulation of transcription during neural development and differentiation, it is not clear whether the enzyme is required during differentiation of human monocytes into macrophages and/or the subsequent transcription of
cytokine genes. To test this, a robust model of differentiation of monocyte-like cells into macrophage-like cells using U937 and HL-60 cells treated with phorbol 12-myristate 13-acetate (PMA) and Lipopolysaccharide (LPS) was validated. Differentiation was determined by morphological and growth characteristics and CD11b surface antigen expression as determined by flow cytometry. qRT-PCR was also used to measure mRNA transcript levels of key genes known to be up-regulated during monocyte differentiation and the secretion of pro-inflammatory cytokines produced by differentiated cells were measured using ELISA.
siRNA topo IIβknockdown did not hinder monocyte-like cells from undergoing differentiation, however experiments revealed a correlation between topo IIβknockdown and secreted TNFα, with the latter decreasing when topo IIβwas reduced. This pattern was also noted when measuring IL-1βsecretion. Similar results were seen using a Murine transgenic fibroblast cell line lacking topo IIβ, which when stimulated with LPS secreted significantly lower levels of IL-6 compared to the wild type cells. Thus topo IIβexpression is necessary for
secretion of normal levels of the cytokines, TNFα, IL-1βand IL-6 in response to LPS at certain time points. In addition in the macrophage-like state of the two cell lines, the relative levels of the βisoform (mRNA and protein) were shown to be significantly increased
compared to α, further outlining the importance of topo IIβin the differentiated state. Chromatin immuno-precipitation followed by qPCR showed however that topo IIβwas not associated at three defined proximal promoter regions of either the TNFαand IL-1βgenes, although further studies are required to rule out a direct association of topo IIβwith these and other regions of the genes.
Down regulation of topo IIβprotein using the inhibitor ICRF-193 did not hinder monocyte-like cells from undergoing differentiation either. However, contrary to the knockdown results, a 6 h pre-treatment with 1 nM ICRF-193 increased TNFαlevels in these cells, both at the
mRNA and the protein level, along with a slight increase in secreted TNFα. NF-κB, EGR2, TLR4 and TLR2 transcript levels were also increased under these conditions. Thus further studies are required to determine if these increases are due to additional cellular effects of the
drug or whether topo IIβmay play an inhibitory effect on transcription.
Thus it is clear that topo IIβplays an important role in expression of cytokines and understanding the exact nature of this requires further research that may yield potential new avenues for treatment of disease
Motivos y justificaciones que condicionan la práctica de compras de prendas de vestir de moda en jóvenes universitarios
No full textEl objetivo original de la investigación, fue estudiar las explicaciones de autores en publicaciones indexadas que hablaran sobre el consumismo en jóvenes universitarios. Es una investigación de tipo documental, de naturaleza cualitativa que se apoyó en fuentes primarias y secundarias, y se contrasta con un ejercicio de campo entrevistando jóvenes universitarios. La población de autores fue de 50 y se escogieron 3 autores. Respecto a las entrevistas la población fueron los estudiantes universitarios entre 18 y 23 años y la muestra por conveniencia fue de 24 hombres y 24 mujeres. En cuanto a la compra frecuente de productos innecesarios se puede evidenciar que 31,3% de los jóvenes pocas veces adquieren productos innecesarios, mientras que otro 31,3 % indican que frecuentemente adquieren productos innecesarios, como también el 6,3% indica que a diario lo hacen, y porcentajes entre 12,5 y 6,3% indican que solo cuando tienen dinero, o simplemente no lo hacen. Por otra parte respecto al atractivo que les impulsa a comprar se puede evidenciar que para el 25% de los estudiantes universitarios de la Universidad Cooperativa de Colombia, el atractivo que los lleva a comprar son todas aquellas cosas que esa de “última moda” y el 18,8% los atrae la ropa que les gusta. Mientras que para el 56,2% los atrae; tener cosas nuevas, marcas reconocidas, vanidad, estar a la moda, necesidad y artículos como relojes, gorras, zapatos. Entre valores como 12,5% y 6,3%.
En conclusión, las causas más comunes que llevan a que se presente este tipo de problemas es la falta de identidad, inseguridad y apoyo emocional. Generando así que el exceso de compras y mal manejo de estas.Por otra parte el hecho de que haya un exceso de compras y mal manejo de estas, genera cierta seguridad y respaldo al momento de obtener algún producto que siempre ha anhelado, pero al pasar los días esa seguridad desaparece, causando la necesidad de comprar.The original objective of the research was to study the explanations of authors in indexed publications that talked about consumerism in university students. It is a documentary research of a qualitative nature that relied on primary and secondary sources, and is contrasted with a field exercise interviewing university students. The author population was 50 and 3 authors were chosen. Regarding the interviews, the population was university students between 18 and 28 years old and the convenience sample was 24 men and 24 women.
Regarding the frequent purchase of unnecessary products, it can be shown that 31.3% of young people rarely acquire unnecessary products, while another 31.3% indicate that they frequently acquire unnecessary products, as also 6.3% indicate that Everyday they do it, and percentages between 12.5 and 6.3% indicate that only when they have money, or simply do not. On the other hand, regarding the attraction that drives them to buy, it can be seen that for 25% of the university students of the Universidad Cooperativa de Colombia, the attraction that leads them to buy are all those things that are the "latest fashion" and the 18.8% are attracted by the clothes they like. While for 56.2% it attracts them; have new things, recognized brands, vanity, be in fashion, need and items such as watches, caps, shoes.
Between values such as 12.5% and 6.3%.
In conclusion, the most common causes that lead to this type of problem is the lack of identity, security and emotional support. Generating that excess of purchases and mishandling of these. On the other hand, the fact that there is an excess of purchases and mismanagement of these, generates some security and support at the time of obtaining a product that has always been desired, but as the days go by that security disappears, causing the need to [email protected]@[email protected]
Gravitational wave burst search in the Virgo C7 data
No full textA search for gravitational wave burst events has been performed with the Virgo C7 commissioning run data that have been acquired in September 2005 over 5 days. It focused on unmodeled short duration signals in the frequency range 150 Hz to 2 kHz. A search aimed at detecting the GW emission from the merger and ring-down phases of binary black hole coalescences was also carried out. An extensive understanding of the data was required to be able to handle a burst search using the output of only one detector. A 90% confidence level upper limit on the number of expected events given the Virgo C7 sensitivity curve has been derived as a function of the signal strength, for unmodeled gravitational wave searches. The sensitivity of the analysis presented is, in terms of the root sum square strain amplitude, h_rss sime 10−20 Hz−1/2. This can be interpreted in terms of a frequentist upper limit on the rate {\cal{R}}_{90\%} of detectable gravitational wave bursts at the level of 1.1 events per day at a 90% confidence level. From the binary black hole search, we obtained the distance reach at 50% and 90% efficiency as a function of the total mass of the final black hole. The maximal detection distance for non-spinning high and equal mass black hole binary system obtained by this analysis in C7 data is sime2.9 ± 0.1 Mpc for a detection efficiency of 50% for a binary of total mass 80 Modot
Joint searches for gravitational waves and high-energy neutrinos
No full textMany of the astrophysical sources and violent phenomena observed in our Universe are potential joint emitters of gravitational waves and high-energy cosmic radiation, in the form of photons, hadrons, and also neutrinos. This has triggered a collaborative analysis project between gravitational wave detectors and high-energy neutrino telescopes. In this article, we review some of the motivations for having pursuing science jointly and present the effort’s status
