566 research outputs found
La riunificazione in mostra. Musei ed esposizioni a Berlino dopo il 1989
No full textL’articolo analizza come i musei di Berlino presentano i temi della rivoluzione pacifica (il processo che condusse al crollo del Muro di Berlino e alla fine della DDR) e della successiva riunificazione tedesca. L’articolo concentra la sua attenzione su quattro differenti musei storici (Deutsches Historisches Museum, DDR-Museum, Mauer-Museum, Stasi-Museum) e analizza inoltre due mostre temporanee («Wir sind das Volk!» e «1990: der Weg zur Einheit»), tenutesi a Berlino nel 2009/2010, in occasione delle celebrazioni del ventennale della rivoluzione pacifica e della riunificazione. Analizzando le diverse strategie espositive e le interpretazioni storiche offerte, l’autore mette in evidenza come i musei e le esposizioni prese in esame vadano a comporre una narrazione articolata ed eterogenea degli eventi dell’89/90. A guidare l’analisi è la consapevolezza del ruolo che i musei giocano nella costruzione della memoria pubblica, aspetto che si cerca di approfondire proprio attraverso questa ricerca.The article aim is to analyze how Berlin museums display the peaceful revolution (the movement that caused the fall of the Berlin Wall and the end of GDR) and the following German reunification. The article focuses on four different historical-museums (Deutsches Historisches Museum, DDR-Museum, Mauer-Museum, Stasi-Museum). Furthermore it examines two temporary exhibitions («Wir sind das Volk!» and «1990: der Weg zur Einheit»), that took place in Berlin in 2009/2010. Looking at the different exhibition strategy and at the slightly different historical interpretations the museums offer, the author underlines how museums and exhibitions develop heterogeneous depiction of the 1989/90 events. The museums role in building the public memory is the key-concept of the article, and this inquiry wants to represent a way to analyze it
Expression of cell-cycle-dependent genes in phytohemagglutinin-stimulated human lymphocytes.
No full textWe have investigated the expression of certain cell-cycle-dependent genes in human peripheral blood mononuclear cells (PBMC) stimulated by phytohemagglutinin (PHA). The genes studied had been previously identified as cell-cycle dependent in other cell types from different species and were induced by different mitogens. One of these genes (2F1) and the gene for the interleukin 2 receptor were induced by PHA even in cultures partially depleted of accessory cells where the lymphocytes grew in size but failed to enter S phase. The other genes (c-myc, 4F1, JE-3, and KC-1) were induced only in complete cultures of PBMC stimulated by PHA. These results confirm the dissociation between growth in size and cell DNA replication that can occur during cell-cycle progression. Moreover, the time course of appearance of detectable levels of RNA for these genes suggests that they may be used as markers of cell-cycle progression in the transition of lymphocytes from G0 to S phase
Effect of interleukin-2 on the expression of cell cycle genes in human T lymphocytes.
No full textWe have studied the expression of seven cell cycle-dependent genes in phytohemagglutinin (PHA)-stimulated peripheral blood mononuclear cells, in macrophage-depleted cultures and in macrophage-depleted cultures plus Interleukin-2 (IL-2). The expression of all seven genes is increased in PHA stimulated peripheral cells. Only two (2F1 and the IL-2 receptor) are increased in PHA-stimulated macrophage depleted cultures. Addition of IL-2 to these cultures increased the RNA levels of four genes (KC-1, c-myc, beta-actin and IL-2R), but has no effect on three others (4F1, 2F1, and JE-3). The results indicate that the expression of these cell cycle genes is regulated by different components of the mitogenic stimulus
Finite element analysis of horizontal axis wind turbines performance
No full textThis paper presents an aeroelastic formulation based on the Finite Element Method (FEM) to predict the performance of an isolated horizontal axis wind turbine. Hamilton's principle is applied to derive the equations of blade(s) aeroelasticity, based on a nonlinear beam model coupled with Beddoes-Leishman unsteady sectional aerodynamics. A devoted fifteen-degrees of freedom finite element, able to accurately model the kinematics and elastic behavior of rotating blades, is introduced and the spatial discretization of the aeroelastic equations is carried-out yielding a set of coupled nonlinear ordinary differential equations that are then solved by a time-marching algorithm. The proposed formulation may be enhanced to face the analysis of advanced blade shapes, including the presence of the tower, and represents the first step of an ongoing activity on wind energy based on a FEM approach. Due to similarities between wind turbine and helicopter rotor blades aeroelasticity, validation results firstly concern with the aeroelastic response of a helicopter rotor in hovering. Next, the performance of a wind turbine in terms of blade elastic response and delivered power are predicted and compared with available literature data
Representations of spectral coordinates in FITS
No full textGreisen & Calabretta (2002, A&A, 395, 1061) describe a generalized
method for specifying the coordinates of FITS data samples. Following
that general method, Calabretta & Greisen (2002, A&A, 395, 1077) describe
detailed conventions for defining celestial coordinates as they are
projected onto a two-dimensional plane. The present paper extends the
discussion to the spectral coordinates of wavelength, frequency, and
velocity. World coordinate functions are defined for spectral axes
sampled linearly in wavelength, frequency, or velocity, linearly in
the logarithm of wavelength or frequency, as projected by ideal
dispersing elements, and as specified by a lookup table
Introduction. Sayad and Migrants’ Descendants: A Renewed Gaze
No full textDespitebeing widely known and cited, Abdelmalek Sayad remains an author subject to divergent representations and interpretations and frequently reduced to a superficial use of some of his most famous concepts. Contrary to this simplifying reading, Sayad’s work crosses different fields of study and is characterised by a particular reflexive depth. Through migration, the author is able to analyse the dynamics of social and symbolic inclusion and exclusion, the construction and modification of social hierarchies at both local and international levels, and social change and conflict at large. In this sense, Sayad also offers important and little explored keys to understanding the experiencesand trajectories of the children of migration. This introductory contribution aims to draw attention to the way Sayad has studied migrants’descendants, highlighting how his approach is helpful for the renewal of this field of study. The contribution concludes with a presentation of the papers that are part of this Special Issue
Monte Carlo simulation to evaluate the contamination in an energy modulated carbon ion beam for hadron therapy delivered by cyclotron
No full textProtons and carbon ion beams for hadron therapy can be delivered by cyclotrons with a fixed energy. In order to treat patients, an energy degrader along the beam line will be used to match the particle range with the target depth. Fragmentation reactions of carbon ions inside the degrader material could introduce a small amount of unwanted contaminants to the beam, giving additional dose to the patient out of the target volume. A simulation study using the FLUKA Monte Carlo code has been carried out by considering three different materials as the degrader. Two situations have been studied: a realistic one, lowering the carbon beam energy from 300 MeV/n to 220 MeV/n, corresponding to a range of 10 cm in water, and the worst possible case, lowering the carbon energy to 50 MeV/n, corresponding to the millimeter range. The main component of the contaminant is represented by alpha particles and protons, with a typical momentum after the degrader greater than that of the primary beam, and can be eliminated by the action of a momentum analyzing system and slits, and by a second thin absorber. The residual component of fragments reaching the patient is negligible with respect to the fragment quantity generated by the primary beam inside the patient before arriving at the end of the target volume
The Jun family members, c-Jun and JunD, transactivate the human c-myb promoter via an Ap1-like element.
No full textThe c-myb protooncogene, which is preferentially expressed in hematopoietic cells at the G1/S boundary of the cell cycle, encodes a transcriptional activator that functions via DNA binding. The regulatory mechanisms governing this specific pattern of expression are not fully understood, although human c-myb expression appears to be positively autoregulated via myb-binding sites in the 5'-flanking region of the c-myb gene (Nicolaides, N. C., Gualdi, R., Casadevall, C., Manzella, L., and Calabretta, B. (1991) Mol. Cell. Biol. 11, 6166-6176). To determine the contribution of other transcription regulators such as JUN family members in the control of c-myb expression, transient expression assays were carried out which revealed a 6- to a 15-fold enhancement by c-Jun and JunD, but not JunB, in chloramphenicol acetyltransferase reporter gene expression driven by different segments of the human c-myb 5'-flanking region. An Ap1-like element located at nucleotide -149 from the c-myb initiation site appears to be required for this transactivation upon binding to a nuclear protein complex containing c-Jun and JunD, since site-directed mutations of this Ap1-like element abolished c-Jun and JunD binding and transactivation. Exposure of phytohemagglutinin-stimulated peripheral blood mononuclear cells to c-jun and junD antisense oligodeoxynucleotides resulted in a 46 and 43% inhibition of T-lymphocyte proliferation that was accompanied by a decrease in c-myb mRNA levels as compared with sense-treated cultures. Because T-lymphocytes induced to proliferate express c-jun and junD before c-myb, these data suggest a mechanism whereby c-Jun and JunD contribute to the transcriptional activation of c-myb that, in turn, is maintained at the G1/S transition and during S phase by positive autoregulation
Cell cycle analysis of human peripheral blood T lymphocytes in long-term culture.
No full textWe have studied the cell cycle of resting T lymphocytes from long-term (LT) cultures following stimulation with phytohemagglutinin (PHA) and recombinant Interleukin 2 (IL-2). We examined the kinetics of entry into S phase by autoradiography, the accumulation of cellular RNA by microfluorometric techniques, and ultrastructural morphology by electron microscopy. In addition, we examined the expression at the mRNA level of six cell cycle-dependent growth-regulated genes (c-fos, c-myc, KC-1, JE-3, vimentin, and histone H3). We show that T lymphocytes of LT cultures respond differently to mitogenic stimulation than the T lymphocytes of freshly isolated peripheral blood mononuclear cell cultures. At the ultrastructural, biochemical, and molecular levels, resting T lymphocytes of LT cultures can be distinguished from physiological (G0) lymphocytes of peripheral blood
Gene-targeted specific inhibition of chronic myeloid leukemia cell growth by BCR-ABL antisense oligodeoxynucleotides.
No full textPhiladelphia-chromosome positive chronic myeloid leukemia cells in chronic phase (CML-CP) or blast crisis (CML-BC) and normal bone marrow cells (NBMC) were incubated in vitro with antisense oligonucleotide specific against the BCR/ABL breakpoint junction to examine the possibility of selective inhibition of leukemia growth. Growth capability was determined in vitro by colony assay in semisolid medium in the presence of interleukin 3 (IL-3) and granulocyte-macrophage colony stimulating factor (GM-CSF). The 18-mer antisense directed against the specific BCR/ABL mRNA breakpoint region diminished the colony formation by CML-CP and CML-BC cells, but not by NBMC. Scrambled oligomer did not affect significantly the growth of leukemic and normal cells. If CML-BC cells were mixed with NMBC and incubated with specific BCR/ABL antisense oligomer, leukemic colonies were selectively inhibited, as was shown by reverse, transcriptase-polymerase chain reaction (RT-PCR) performed to detect BCR/ABL mRNA in single colonies. These results confirm the possibility of selective inhibition of leukemia cells by antisense treatment
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