2,943 research outputs found
Growth and apoptosis pathways in human cutaneous melanoma: in vitro and in vivo studies by using biological and proteomics approaches
Purpose. Melanoma is the most aggressive cutaneous cancer without effective treatment. Diagnosis is achieved very often too late and prognosis is poor. Aim of this work is to identify proteomic pathways potentially involved in melanoma aggressiveness.
Materials and Methods. We analyzed 5 human metastatic melanoma cell lines and human keratinocyte and melanocyte cell lines as a control. Their proliferation and apoptotic behaviors under serum stimulation and starvation were analyzed in order to identify the most aggressive one. Melanoma cell proteome from the most aggressive cell line (A375), compared to the less aggressive one (SK mel 28), was analyzed by means of two complementary approaches: 1) multiplexed assay to measure the levels of 27 cytokines both in cell extracts and in conditioned media; 2) proteomic study through LC-MS/MS analysis of cell extracts. Data obtained were analyzed using bioinformatic analysis.
Results. A375 cells were found to possess the highest growth rate both under serum stimulation and under serum starvation, while SK mel 28 cells under similar conditions were significantly less aggressive, confirmed also by invasion assays. The effect was markedly cell-density dependent, suggesting that cell-cell interaction and/or secretory signals dependent phenomena are important. Proteome analyses indicated that several proteins are differentially expressed and possibly related the aggressiveness. Some of these proteins have been identified as transport and proteasome components. The Bio-Plex analysis of the melanoma cell lines under study indicated that melanoma cells contain significantly (p<0.001) different levels of some inflammatory cytokines and angiogenic growth factors: the most significantly modified factors were IL-6, Il-7, RANTES and VEGF, suggesting a novel interesting viewpoint to explain melanoma cell aggressiveness.
Conclusions. The reported results show that transport, proteasome components and an altered cytokine balance may be responsible for human melanoma aggressiveness
A test for the too big to fail hypothesis for european banks during the financial crisis
Motivated by the theoretical prediction of
the opportunistic behaviour of large banks that face expected public intervention, we test a
fulland a partial form of the too-big-to-fail (TBTF) hypothesis. The full form of the hypo
thesis implies the increase in the risk undertakings and profitability of banks that exceed a certain dimension; the partial form of the hypothesis implies only an augmented risk appetite of large banks compared to their smaller counterparts. The examined area is the European banking industry, whose behaviour is observed over the first wave of the present financial crisis (2007-2009). The estimation of a quadratic fit that links change in a bank’s credit risk
profile and profitability retention rates with a
bank’s size suggests the existence of a partial
form of the TBTF hypothesis. However, a more precise, local rolling - window estimation of the size sensitivities reveals that large banks whose liabilities exceed approximately 2% of the country of origin’s GDP (15% of our sample), and an increase in credit risk profile show, vis-à-
vis their smaller counterparts, a superior capability of retaining higher ROA scores. With the caveats of our investigation, we interpret these results as evidence of a full form of the TBTF hypothesis.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
An efficiency analysis of banking systems: a comparison of European and United States large commercial banks using different functional forms.
This paper aims at investigation the efficiency of European and U.S. commercial banks. Scale and scope economies indicators, as well as a measurement of X-efficiency are derived from three cost functions: Fourier flexible form, translog and Box-Cox. This allows checking the stability and the robustness of the evidence across the different specifications. Our results over the period 1995-98 show that overall the average cost curve is relatively flat with some evidence of scale efficiency gains. More puzzling are the results on the presence of scope economies.
Innovative interventions in support of innovation networks. A complex system perspective to public innovation policy and private technology brokering
The linear model of innovation has been superseded by a variety of theoretical models that view the innovation process as systemic, complex, multi-level, multi-temporal, involving a plurality of heterogeneous economic agents. Accordingly, the emphasis of the policy discourse has shifted over time. It has gone from a focus on direct public funding of basic research as an engine of innovation, to the creation of markets for knowledge goods, to, eventually, the acknowledgement that knowledge transfer very often requires direct interactions among innovating actors. In most cases, these interventions attempt to facilitate the match between “demand” and “supply” of the knowledge needed to innovate. A complexity perspective calls for a different framing, one focused on the fostering of process characterized by multiple agency levels, multiple temporal scales, ontological uncertainty and emergent outcomes. The article explores what it means to design interventions in support of innovation processes inspired by a complex systems perspective. It does so by analyzing two different examples of coordinated interventions: an innovative public policy funding networks of innovating firms, and a private initiative supporting innovation in the mechanical engineering industry thanks to the set up of a technology broker. Relying on two unique datasets recording the interactions of the various organizations involved in these interventions, the article combines social network analysis and qualitative research in order to investigate the dynamics of the networks and the roles and actions of specific actors in fostering innovation processes. Building upon this comparative analysis, some general implications for the design of coordinated interventions supporting innovation in a complexity perspective are derived.Innovation policy; local development policies; regional development policies; evaluation management
Oscillatory dynamics in nanocavities with noninstantaneous Kerr response
We investigate the impact of a finite response time of Kerr nonlinearities
over the onset of spontaneous oscillations (self-pulsing) occurring in a
nanocavity. The complete characterization of the underlying Hopf bifurcation in
the full parameter space allows us to show the existence of a critical value of
the response time and to envisage different regimes of competition with
bistability. The transition from a stable oscillatory state to chaos is found
to occur only in cavities which are detuned far off-resonance, which turns out
to be mutually exclusive with the region where the cavity can operate as a
bistable switch
Eimeria legionensis and Eimeria kofoidi (Apicomplexa: Eimeriidae) infection and associated lesions in naturally infected red-legged partridges (alectoris rufa)
With the aim to identify the Eimeria species responsible for coccidiosis in 50 deceased red-legged partridges (Alectoris rufa), individual faecal samples were collected, dissolved in 2.5% K2Cr2O7 solution and maintained at room temperature to allow sporulation of the oocysts. Morphology and dimensions of sporulated oocysts were microscopically evaluated. To assess Eimeria intestinal localisation, faecal samples and scrapings taken from the different intestinal segments of each deceased animal were examined by fresh smears and flotation test, while the intestines were examined for gross lesions, then fixed in 10% formalin and processed for histopathological analysis. From scrapings and morphological analysis, Eimeria kofoidi and Eimeria legionensis were identified in the small intestine and in the caecum and colon, respectively. Histopathological analysis confirmed the presence of two distinct Eimeria species. In particular, E. kofoidi macrogamonts were found in epithelial cells of jejunum and ileum, between the basal lamina and the nucleus of the infected intestinal cells. This latter was flattened and displaced above. E. legionensis macrogamonts were instead found localised between the nucleus and the luminal surface of the infected caeca and colonic cells and these macrogamonts were larger than those of E. kofoidi. Chronic enteritis and severe displacement of the deep crypts of the small intestine, large areas of caeca and colonic epithelial necrosis associated to thickened wall and mononuclear cells infiltration diffused in a transmural manner, were the main histopathological lesions
Enargite by XPS
X-ray photoelectron spectroscopy was used for characterizing the enargite surface. Freshly cleaved samples were analyzed at liquid nitrogen temperature. Enargite is a copper arsenic sulfide of formula Cu3AsS4; it is used as a minor ore of copper. Enargite is a potential source of arsenic and may create environmental problems through the release of toxic elements upon oxidatio
First report on egg-parasitoids of the Asian planthopper Ricania speculum
The first findings of egg-parasitoids of the invasive planthopper Ricania speculum (Walker) (Hemiptera Ricaniidae) are presented.
Aprostocetus (Ootetrastichus) crino (Walker) (Hymenoptera Eulophidae), a native species until now only associated with Oecanthus
spp. (Orthoptera Oecanthidae) eggs, was the most common. Chaetostricha similis (Silvestri) (Hymenoptera Trichogrammatidae)
and Polynema sp. (Hymenoptera Mymaridae), which also emerged from R. speculum egg clusters, should be confirmed as
parasitoids of this planthopper
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