156 research outputs found

    The Power of Participatory Photography in ICTD Programs: Freedom to Explore beyond Images

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    We discuss the contribution of participatory photography as a method to elicit lived experiences from the perspectives of participants, a valuable tool in ICTD research. Building on a participatory photography research project with Latino migrants in Seattle, Washington (USA) and at the US-Mexico border, we analyze the differences between descriptive accounts and interpretations of photographs offered by participants. By opening new possibilities for self-expression, participatory photography offers a powerful tool that allows participants to add not just description but also context, representations, meanings, feelings and memories, among other interpretations. Different effects of the participants’ photographs are also analyzed, to encourage further exploration of participatory photography in ICTD research

    Intersectoral and spatial spill-overs of firms’ bankruptcy in Spain

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    This paper employs provincial data to study the spatial and intersectoral spill-overs in aggregate failure rates in Spain, by using an Integrated Nested Laplace Approximation. The analysis is based on NUTS3 data over the time span 2005Q1-2013Q4. By speculating on the effects of the Spanish financial crisis, we document empirical evidence of the presence of spatial spill-overs among neighboring counties. Furthermore, some intersectoral spill-overs are also detected: we observe that Industry and Agriculture exhibit a positive impact on the Service sector. These results can be useful to design proper policy rules to better manage the spread of bankruptcies over time and space

    Experimental features affecting the transparency of YAG materials

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    The important role played by the processing on the transparency of ceramic materials is often underestimated. In the literature a high level of transparency has been reported by many authors that for years focused their research on the development of polycrystalline YAG for laser applications,but the description of the experimental process is seldom thoroughly described. A detailed description of the powder treatment and shaping and of other important information that are necessary to reproduce the described results, is often missing. In order to be transparent a ceramic material must exhibit a very low concentration of defects such as secondary or grain boundary phases and residual pores. In order to fulfill this requirement specific experimental conditions must be combined together. Powders need to be nanometric or at least sub-micrometric and extremely pure. On the other hand, nanometric powders aggregate easily and the poor packing that may derived can lead to residual porosity. In addition, very fine powders are difficult to handle and tend to absorb water on the surface. Finally, the powder manipulation (weighting operations, solvent removal, spray drying, shaping, etc), easily introduces impurities. In case of transparent materials all these features must be controlled because they lead to the formation of defects that works as light scattering sources thus decreasing the transparency. This work describes the results obtained with YAG based ceramics under different experimental conditions of powder treatment and shaping. Commercial powders are used for the reactive sintering in a clean atmosphere and under high vacuum of YAG materials doped with Nd, Yb or Er. These dopants have been selected as the more appropriate for high power lasers. The powder treatment (ball milling duration and speed, suspension concentration, solvent/powder ratio, type and amount of dispersant) the solvent removal technique (spray drying conditions, rotavapor temperature, etc.) are described in detail as well as the conditions adopted during shaping. The influence of the powder process on the powder packing during shaping by pressing is also reported. Finally, the influence of the pre-sintering and sintering cycles is also described

    Circulating tumour cells in colorectal cancer

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    Abstract Background The detection of circulating tumour cells (CTC) in blood sample in patients with early or advanced colorectal cancer has a potential prognostic value. Methods The challenge of CTC detection is related to the requirement of high sensitivity combined with high specificity method. CTCs detection can be distinguished between indirect and direct methods. The former ones are based on the recognition of tissue-, organ- or tumour-specific markers by immuno-histochemistry (indirect immuno-mediated methods) or (real-time) RT-PCR (indirect molecular methods), whilst the latter are related to CTCs selection based on the physical properties of density and sizes. Ongoing and future isolation by size of epithelial tumour cells (ISET) developments concerning automated image analysis on the filter and transmission of high definition images through the web for 'on line' cytopathological consultations are aimed to speed up the work of cytopathologists on CTC/ circulating tumour microemboli (CTM) detection. Conclusions CTC detection in colorectal cancer (CRC) correlates with pathological stage and clinical outcome in particular in those patients with advanced disease. CRC CTC level before and after CT are an independent prognostic factor for progression-free and overall survival. The positive prognostic value of complete clearance CTC after surgery may be useful to select patients for adjuvant chemotherapy

    Current status of the research on transparent YAG ceramics as laser hosts from an Italian network

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    This work describes the results obtained using two different processing systems for the production of YAG based ceramics. One involves the use of commercially available oxide powders (Yb2O3, Y2O3, Al2O3) The other involves the use of Yb-doped Y2O3 (Yb, 9.8%) powders obtained by microwave assisted co-precipitation from salts solution and a commercial alumina (Al2O3). Both systems are processed by wet mechanical mixing of starting oxides and reactive sintering of the obtained mixtur

    Study of molecular mechanisms of pro-apoptotic activity of NCX 4040, a novel nitric oxide-releasing aspirin, in colon cancer cell lines

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    <p>Abstract</p> <p>Background</p> <p>Despite numerous studies aimed at verifying the antitumor activity of nitric oxide-releasing nonsteroidal antiflammatory drugs (NO-NSAIDs), little is known about the molecular targets responsible for their antineoplastic properties. In the present study, we investigated the mechanisms underlying the cytotoxicity of NCX 4040, a novel NO-aspirin with promising antineoplastic action, in <it>in vitro </it>human colon cancer models.</p> <p>Methods</p> <p>The effect on tumor growth was evaluated in four human colon cancer cell lines (LoVo, LRWZ, WiDr and LoVo Dx) by sulforhodamine B assay, oxidative stress by immunohistochemistry, apoptosis by laddering assay, mitochondrial membrane potential (ΔΨ<sub>m</sub>) by flow cytometry, and apoptosis- and chemoresistance-related markers by western-blot and real-time method, respectively. Prostaglandin E<sub>2 </sub>levels were determined by ELISA.</p> <p>Results</p> <p>NCX 4040 produced a higher cytotoxic effect in all the cell lines than that produced by other NO donors tested. In particular, in LoVo and LRWZ cells, NCX 4040 induced a cytocidal effect and apoptosis through p53 and NAG-1 expression, an early ΔΨ<sub>m </sub>collapse, and a sequential release of cytoplasmatic cytochrome c and caspase -9 and -3 active forms. 8-hydroxyguanine lesions, indicative of oxidative stress, were also observed. Conversely, in WiDr line, the drug caused a cytocidal effect, albeit not through apoptosis, and a concomitant increase in COX-2 activity. In LoVo Dx line, characterized by high levels drug resistance and DNA repair-related markers, only a cytostatic effect was observed, again in concomitance with the increase in COX-2 enzyme activity.</p> <p>Conclusion</p> <p>This study highlights the multiplicity of mechanisms involved in sensitivity or resistance to NCX 4040 and could provide useful indications for tailored therapy by identifying potentially drug-responsive tumors.</p

    Evaluation of the activity of natural phenolic antioxidants, extracted from industrial coffee residues, on the stability of poly(1,4‐butylene succinate) formulations

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    In this work, the evaluation of the antioxidant activity of natural phenolic compounds is performed and compared to that of a conventional antioxidative agent. Phenolic molecules, extracted from industrial processing coffee residues, are added to a matrix of poly(1,4-butylene succinate) (PBS). The apparent activation energy (Ea) of the thermo-oxidative degradation is calculated by employing different methods like Kissinger-Akahira-Sunose, Flynn-Wall-Ozawa and Friedman. The results are compared with the antioxidant activity evaluation obtained through the ABTS radical scavenging assay. From the average activation energies, it is observed that the addition of the natural antioxidants led to an increase in the activation energy of the degradation process as a function of the phenolic compound content. This trend is confirmed by the results of the ABTS assay. Hence, this study proves that the active molecules extracted from agri-food waste could be employed to improve the antioxidant capacity of the biopolymer, even if the composition of the extract must be evaluated in order to mitigate the effects of other components

    The role of activity in synaptic degeneration in a protein misfolding disease, prion disease

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    In chronic neurodegenerative diseases associated with aggregates of misfolded proteins (such as Alzheimer's, Parkinson's and prion disease), there is an early degeneration of presynaptic terminals prior to the loss of the neuronal somata. Identifying the mechanisms that govern synapse degeneration is of paramount importance, as cognitive decline is strongly correlated with loss of presynaptic terminals in these disorders. However, very little is known about the processes that link the presence of a misfolded protein to the degeneration of synapses. It has been suggested that the process follows a simple linear sequence in which terminals that become dysfunctional are targeted for death, but there is also evidence that high levels of activity can speed up degeneration. To dissect the role of activity in synapse degeneration, we infused the synaptic blocker botulinum neurotoxin A (BoNT/A) into the hippocampus of mice with prion disease and assessed synapse loss at the electron microscopy level. We found that injection of BoNT/A in naïve mice caused a significant enlargement of excitatory presynaptic terminals in the hippocampus, indicating transmission impairment. Long-lasting blockade of activity by BoNT/A caused only minimal synaptic pathology and no significant activation of microglia. In mice with prion disease infused with BoNT/A, rates of synaptic degeneration were indistinguishable from those observed in control diseased mice. We conclude that silencing synaptic activity neither prevents nor enhances the degree of synapse degeneration in prion disease. These results challenge the idea that dysfunction of synaptic terminals dictates their elimination during prion-induced neurodegeneration

    Longitudinal Bottom-Up Proteomics of Serum, Serum Extracellular Vesicles, and Cerebrospinal Fluid Reveals Candidate Biomarkers for Early Detection of Glioblastoma in a Murine Model

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    Glioblastoma Multiforme (GBM) is a brain tumor with a poor prognosis and low survival rates. GBM is diagnosed at an advanced stage, so little information is available on the early stage of the disease and few improvements have been made for earlier diagnosis. Longitudinal murine models are a promising platform for biomarker discovery as they allow access to the early stages of the disease. Nevertheless, their use in proteomics has been limited owing to the low sample amount that can be collected at each longitudinal time point. Here we used optimized microproteomics workflows to investigate longitudinal changes in the protein profile of serum, serum small extracellular vesicles (sEVs), and cerebrospinal fluid (CSF) in a GBM murine model. Baseline, pre-symptomatic, and symptomatic tumor stages were determined using non-invasive motor tests. Forty-four proteins displayed significant differences in signal intensities during GBM progression. Dysregulated proteins are involved in cell motility, cell growth, and angiogenesis. Most of the dysregulated proteins already exhibited a difference from baseline at the pre-symptomatic stage of the disease, suggesting that early effects of GBM might be detectable before symptom onset
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