1,560 research outputs found

    Type I collagen limits VEGFR-2 signaling by a SHP2 protein-tyrosine phosphatase-dependent mechanism 1.

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    During angiogenesis, a combined action between newly secreted extracellular matrix proteins and the repertoire of integrins expressed by endothelial cells contributes in the regulation of their biological functions. Extracellular matrix-engaged integrins influence tyrosine kinase receptors, thus promoting a regulatory cross-talk between adhesive and soluble stimuli. For instance, vitronectin has been reported to positively regulate VEGFR-2. Here, we show that collagen I downregulates VEGF-A-mediated VEGFR-2 activation. This activity requires the tyrosine phosphatase SHP2, which is recruited to the activated VEGFR-2 when cells are plated on collagen I, but not on vitronectin. Constitutive expression of SHP2(C459S) mutant inhibits the negative role of collagen I on VEGFR-2 phosphorylation. VEGFR-2 undergoes internalisation, which is associated with dynamin II phosphorylation. Expression of SHP2(C459S) impairs receptor internalisation suggesting that SHP2-dependent dephosphorylation regulates this process. These findings demonstrate that collagen I in provisional extracellular matrix surrounding nascent capillaries triggers a signaling pathway that negatively regulates angiogenesis

    Participatory analysis for adaptation to climate change in Mediterranean agricultural systems: possible choices in process design (versão Pre Print)

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    There is an increasing call for local measures to adapt to climate change, based on foresight analyses in collaboration with actors. However, such analyses involve many challenges, particularly because the actors concerned may not consider climate change to be an urgent concern. This paper examines the methodological choices made by three research teams in the design and implementation of participatory foresight analyses to explore agricultural and water management options for adaptation to climate change. Case studies were conducted in coastal areas of France, Morocco, and Portugal where the groundwater is intensively used for irrigation, the aquifers are at risk or are currently overexploited, and a serious agricultural crisis is underway. When designing the participatory processes, the researchers had to address four main issues: whether to avoid or prepare dialogue between actors whose relations may be limited or tense; how to select participants and get them involved; how to facilitate discussion of issues that the actors may not initially consider to be of great concern; and finally, how to design and use scenarios. In each case, most of the invited actors responded and met to discuss and evaluate a series of scenarios. Strategies were discussed at different levels, from farming practices to aquifer management. It was shown that such participatory analyses can be implemented in situations which may initially appear to be unfavourable. This was made possible by the flexibility in the methodological choices, in particular the possibility of framing the climate change issue in a broader agenda for discussion with the actors

    Inter-basin transfers as a supply option: the end of an era?

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    International audienceThis chapter discusses the evolving role of interbasin transfers (IBT) in urban water management. After providing an historical overview of IBT development, the chapter describes how IBTs are challenged by a change in the technological and socio-economic context. The emergence of alternative technologies, such as desalination, wastewater reclamation and reuse, or managed artificial groundwater recharge is reducing the attractiveness of IBTs. Water utilities are also becoming increasingly aware that water conservation programs can save volumes of water at a much cheaper cost than IBT. Various international examples are used to show that IBTs trigger increasing concerns from communities involved or affected, in particular related to the environmental impact on donor and receiving river basins, the economic impact on donor regions, the impact on local cultures and livelihoods, how costs and benefits are distributed (social justice), and issues related to public participation. The chapter concludes by looking ahead at new and more efficient uses of existing IBTs. As conjunctive use management approaches gain support, IBTs will be operated in conjunction with aquifer storage and recovery schemes. They will probably also support the development of emerging water markets, in particular during drought years

    Uso de tiras reactivas en muestras de moco cérvico-vaginal de vacas con endometritis subclínica

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    La endometritis causa pérdidas productivas en la industria láctea. La endometritis subclínica (ES) se define por presencia de neutrófilos (PMN N) en la luz uterina en ausencia de signos clínicos y el diagnóstico se realiza por cytobrush (CB). El moco cérvico-vaginal (MCV) se obtiene rápidamente y es utilizado como fuente de información del tracto reproductor. El objetivo de este trabajo fue evaluar en MCV pH, actividad de enzima esterasa leucocitaria (LE) y utilidad de la misma como diagnóstico de endometritis ES. Se utilizaron 100 vacas Holando Argentino de dos tambos de la cuenca lechera sur Santa Fe, de 21–56 días postparto. Se clasificaron según tipo de MCV y CB (punto de corte ≥5% PMN N) en vacas con Endometritis Clínica (EC) (control positivo), Endometritis Subclínica y Estatus uterino sano (S) (control negativo). Se utilizaron tiras reactivas “Urine Strip Wiener lab” y para la lectura se usó como referencia la tabla otorgada por el fabricante. Se evaluó el % de PMN N para cada rango de LE 0(-), 0.5 (+/-), 1 (+), 2 (++) y 3 (+++). Los métodos estadísticos aplicados fueron t-test, ANOVA (p<0.05), prueba de sensibilidad (Sen) y especificidad (Esp). Lectura de LE: S 5% positivo, ES 86% positivo, EC 96% positivo. La prueba de esterasa leucocitaria reveló 86% Sen y 95% Esp, Likelihood Ratio (LR) 16.41 (utilidad altamente relevante) para el diagnóstico de ES y 96% Sen y 94% Esp, LR 18.21 para EC. Se encontraron diferencias entre el % PMN N para cada rango (p<0.0001), así como en el valor de pH (p=0.0026), siendo más alcalino en MCV de hembras con ES (8.5±0.5) versus S (8.2±0.6) y EC (7.9±0.6). En conclusión, las tiras reactivas de LE y pH son una herramienta complementaria prometedora para usar a campo en muestras de MCV para el diagnóstico de ES

    DOCUMENTATION FOR ENVIRONMENTAL RISK ASSESSMENT AND MITIGATION OF BUILT CULTURAL HERITAGE IN CENTRAL ASIA: THE ERAMCA PROJECT

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    The ERASMUS+ initiative funded, in 2019, a Capacity Building project named ERAMCA (Environmental Risk Assessment and Mitigation in Central Asia) to build up a study plan at the Master of Science level (120 ECTS in 2 academic years) open to Architects, Civil, Building, and Environmental Engineers to build-up a new generation of professionals able to work in a team with different specialities to document Cultural Heritage assets by considering environmental risks. These new professionals will be able to set up the helpful basic knowledge to plan future actions of preservation and enhancement by following the most recent development in the restoration field at the international level.The ERAMCA project started with a survey of the basic knowledge of architects and engineers in Uzbekistan and Tajikistan on the documentation of natural and anthropic risks.By considering the common knowledge, the Partners of the ERAMCA project (3 European Universities from Italy, Germany, and Croatia and 4 Universities from Uzbekistan and Tajikistan) realised a study plan by concentrating the teaching activity on the following disciplines: Geomatics, Restoration, Structure and Seismic Engineering, Hydrogeology and Geotechnics.ERAMCA project is in its last year of activity, and the final results can be presented and discussed among the Cultural Heritage Documentation community to offer possible suggestions for future actions to diffuse documentation strategies.</p

    Social-ecological features of set nets small-scale fisheries in the context of Mediterranean marine protected areas

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    The small-scale fisheries (SSF) sector has attracted considerable attention over the last decade due to its major importance in sustaining the livelihoods of coastal communities worldwide, poverty alleviation, food security, social wealth and traditions. Despite this importance, quantitative and qualitative information on SSF is still largely lacking and when available, it tends to be scattered or very localized. SSF are also among the very few professional extractive activities generally allowed within Marine Protected Areas (MPAs), and are therefore expected to acquire further momentum in the near future in light of the projected increase of protected marine surface area due to international commitments. However, SSF associated with areas including MPAs may differ from those operating in unprotected contexts with regard to a range of socio-ecological aspects, thus potentially making management strategies currently in force unsuitable, and requiring the development of ad hoc local and regional policies. Here, we assessed the socio-ecological dimension of SSF operating within and around 11 Mediterranean MPAs, in six EU countries, with the aim of identifying relevant patterns that could inform policy and management relative to this fishing sector in view of the forthcoming increase of the marine surface area under protection. To do so, we have adopted a collaborative approach with fishers and combined a photo-sampling survey of 1,292 set net (mainly trammel-nets) fishing operations at landing with 149 semi-structured interviews with fishers, to gather information on features and catches of SSF fleets (e.g. vessel characteristics, gears, catch composition, catch and revenue per unit of effort). Overall, results highlighted: 1) multiple shared features emerging at regional level (i.e. among the 11 study areas), such as the predominant use of set nets, the major contribution of a limited number of species to the overall catch and revenue, the occurrence in the catch of threatened species and/or undersized individuals; 2) a variety of distinctive socio-ecological features differentiating local SSF communities such as the species mainly contributing to catch and revenue, species size distribution and fleet characteristics. In addition to presenting elements to inform common policies and strategies for SSF management in the context of MPAs, our study provides guidance for the development of a standard methodology for the full documentation of SSF in the Mediterranean Sea

    Search for charginos in e+e- interactions at sqrt(s) = 189 GeV

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    An update of the searches for charginos and gravitinos is presented, based on a data sample corresponding to the 158 pb^{-1} recorded by the DELPHI detector in 1998, at a centre-of-mass energy of 189 GeV. No evidence for a signal was found. The lower mass limits are 4-5 GeV/c^2 higher than those obtained at a centre-of-mass energy of 183 GeV. The (\mu,M_2) MSSM domain excluded by combining the chargino searches with neutralino searches at the Z resonance implies a limit on the mass of the lightest neutralino which, for a heavy sneutrino, is constrained to be above 31.0 GeV/c^2 for tan(beta) \geq 1.Comment: 22 pages, 8 figure

    Hadronization properties of b quarks compared to light quarks in e+e- -> q qbar from 183 to 200 GeV

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    The DELPHI detector at LEP has collected 54 pb^{-1} of data at a centre-of-mass energy around 183 GeV during 1997, 158 pb^{-1} around 189 GeV during 1998, and 187 pb^{-1} between 192 and 200 GeV during 1999. These data were used to measure the average charged particle multiplicity in e+e- -> b bbar events, _{bb}, and the difference delta_{bl} between _{bb} and the multiplicity, _{ll}, in generic light quark (u,d,s) events: delta_{bl}(183 GeV) = 4.55 +/- 1.31 (stat) +/- 0.73 (syst) delta_{bl}(189 GeV) = 4.43 +/- 0.85 (stat) +/- 0.61 (syst) delta_{bl}(200 GeV) = 3.39 +/- 0.89 (stat) +/- 1.01 (syst). This result is consistent with QCD predictions, while it is inconsistent with calculations assuming that the multiplicity accompanying the decay of a heavy quark is independent of the mass of the quark itself.Comment: 13 pages, 2 figure

    Cell delivery systems using alginate : carrageenan hydrogel beads and fibers for regenerative medicine applications

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    The present work was focused on the development and characterization of new hydrogel systems based on natural origin polymers, namely, alginate and carrageenan, into different formats and with adequate properties to sustain the viability of encapsulated cells, envisioning their application as cell delivery vehicles for tissue regeneration. Different formulations of alginate and carrageenan hydrogels and different processing parameters were considered to determine the best conditions required to achieve the most adequate response in terms of the mechanical stability, cell viability, and functionality of the developed systems. The morphology, size, and structure of the hydrogels and their degradation behavior and mechanical properties were evaluated during this study. In addition to cytotoxicity studies, preliminary experiments were carried out to investigate the ability of alginate−carrageenan beads/fibers to encapsulate chondrocytes. The results obtained indicated that the different formulations, both in the form of beads and fibers, have considerable potential as cell-carrier materials for cell delivery in tissue engineering/ regenerative medicine applications.European NoE EXPERTISSUES - NMP3-CT-2004-500283Fundação para a Ciência e a Tecnologia (FCT) - SFRH/BD/64070/2009

    Search for composite and exotic fermions at LEP 2

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    A search for unstable heavy fermions with the DELPHI detector at LEP is reported. Sequential and non-canonical leptons, as well as excited leptons and quarks, are considered. The data analysed correspond to an integrated luminosity of about 48 pb^{-1} at an e^+e^- centre-of-mass energy of 183 GeV and about 20 pb^{-1} equally shared between the centre-of-mass energies of 172 GeV and 161 GeV. The search for pair-produced new leptons establishes 95% confidence level mass limits in the region between 70 GeV/c^2 and 90 GeV/c^2, depending on the channel. The search for singly produced excited leptons and quarks establishes upper limits on the ratio of the coupling of the excited fermio
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