1,740 research outputs found

    Outsourcing the State’s responsibilities? Third sector organizations supporting migrant families’ participation in schools in Catalonia and London

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    Based on two case studies of Third Sector Organizations (TSOs) working with schools and parents in Catalonia and London, this paper aims to discuss some of the implications of ‘participative’ programs aimed at involving those migrant families seen by schools as ‘hard to reach’. Firstly, we describe how an ambiguous notion of participation can shift responsibilities to families and leave internal school practices free from critical gaze. Secondly, we focus on the complexities and tensions involved in the process of partnering TSOs with schools, because of the bureaucratic nature of educational institutions and unresolved conflicts of interests and responsibilities. Finally, we argue that the potential of these initiatives were limited and diluted by being stand-alone and time-limited. Our analysis suggests that, in spite of their apparent success, they ended up being part of powerful authorizing narratives that justify the outsourcing of public services and the abdication of State’s responsibilities

    BME children in London: educational needs and the role of community organisations. (An evaluation of the education services of Day-Mer, Turkish and Kurdish Community Centre)

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    London’s diversity is reflected in its school population: almost 65% of pupils in primary and secondary schools are of ‘ethnic minority’ background. Over the years, research has shown that migrant and BME children and families face a number of obstacles, including limited English language, lack of knowledge of the British education system, racism and social exclusion. One of the consequences is the significant difference in terms of school achievement among pupils of certain backgrounds. Groups long considered underachievers include in particular Pakistani, Bangladeshi and Black Caribbean, although more recent studies have also identified similar educational problems among Somali and Turkish-speaking pupils. In this respect, the role played by community organisations - including supplementary classes, schools support and parental engagement programmes - is highly valued by both families and teachers. Despite limited systematic evidence, research suggests the impact of these organisations is highly significant and more should be done to encourage partnership work between mainstream schools and community groups. In the last few years, however, community organisations have faced a number of new challenges, including a dramatic reduction of public funding available and major changes in educational policy, such as the closure of the ‘Ethnic Minority Achievement Grant’ programme and the introduction of new models of schools increasingly independent from local authority control. In this new scenario it is more important than ever to learn from the experiences of these organisations in order to identify good practices and address issues of sustainability. This can inform policy makers and practitioners in ensuring that children from all ethnic backgrounds receive the educational support they need. In Spring 2011 - building on previous research conducted at Middlesex University - Day-Mer and the Social Policy Research Centre (SPRC) came together to work on a research project on the educational needs of Turkish and Kurdish families in North London. The project focuses on Day-Mer’s experience to evaluate the effectiveness of its services, but is also builds on this case study to discuss more broadly the role of community organisations in providing educational support

    Virtuous Disassembly: Material and Ethical Practice of a Global Electronic Waste Regime

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    International regulations have sought to curb illicit flows of electronic waste (e-waste) from Global North countries to Global South countries. At the same time, they provide a means for certified recyclers to imagine themselves as moral entrepreneurs with coherent industrial practices. Making the most value from discarded machines, however, is a process that requires careful attention to the indeterminate materiality of their supply. Used machines’ materiality is made indeterminate by the unpredictable amount of human wear on each machine. What this entails for the recycler is a process in negotiation with these unique conditions. Based on fieldwork and interviews with Euroamerican recyclers, brokers, auditors, and regulations staff, this thesis studies the moment a certified recycler decides how to process a discarded machine. It argues that the materiality of used electronics guides the production of ethical meanings and economic value

    Correlations between reflected and transmitted intensity patterns emerging from opaque disordered media

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    The propagation of monochromatic light through a scattering medium produces speckle patterns in reflection and transmission, and the apparent randomness of these patterns prevents direct imaging through thick turbid media. Yet, since elastic multiple scattering is fundamentally a linear and deterministic process, information is not lost but distributed among many degrees of freedom that can be resolved and manipulated. Here we demonstrate experimentally that the reflected and transmitted speckle patterns are correlated, even for opaque media with thickness much larger than the transport mean free path, proving that information survives the multiple scattering process and can be recovered. The existence of mutual information between the two sides of a scattering medium opens up new possibilities for the control of transmitted light without any feedback from the target side, but using only information gathered from the reflected speckle.Comment: 6 pages, 4 figure

    Nanostructural differences in pectic polymers isolated from strawberry fruits with low expression levels of pectate lyase or polygalacturonase genes

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    Our research group has obtained transgenic strawberry plants expressing antisense sequences of either a pectate lyase (APEL lines) [1] or a polygalacturonase gene (APG lines) [2]. Both genes encode ripening-specific endo-pectinases with a common target, deesterified homogalacturonans, but each enzyme act by a different mechanism and pH range. Ripe fruits from both transgenic genotypes were significantly firmer than control, being APG fruits on average 25% firmer than APEL fruits. Cell wall analysis of both transgenic genotypes indicated that pectin fractions extracted with CDTA and sodium carbonate were significantly modified in transgenic fruits [2,3]. To gain insight in the role of these pectinases in pectin disassembly during ripening, CDTA and Na2CO3 pectins have been analyzed by atomic force microscopy (AFM). APEL and APG CDTA pectins had similar contour lengths but both were significantly longer than control. Similarly, APG carbonate chains were longer than control, showing APEL carbonate chains an intermediate length. Furthermore, transgenic pectins displayed a more complex branching pattern and a higher number of micellar aggregates, especially in the sodium carbonate fractions of APG samples. Acid hydrolysis of carbonate pectins reduced the number of micellar aggregates. AFM analyses confirm that the inhibition of both pectinases reduces pectin disassembly, and also suggest that each pectinase acts on specific pectin domains. Particularly, polygalacturonase silencing induces more significant pectin modifications, nicely correlated with the firmer phenotype of APG fruits, than the down-regulation of pectate lyase

    Broadband telecom transparency of semiconductor-coated metal nanowires: more transparent than glass

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    Metallic nanowires (NW) coated with a high permittivity dielectric are proposed as means to strongly reduce the light scattering of the conducting NW, rendering them transparent at infrared wavelengths of interest in telecommunications. Based on a simple, universal law derived from electrostatics arguments, we find appropriate parameters to reduce the scattering efficiency of hybrid metal-dielectric NW by up to three orders of magnitude as compared with the scattering efficiency of the homogeneous metallic NW. We show that metal@dielectric structures are much more robust against fabrication imperfections than analogous dielectric@metal ones. The bandwidth of the transparent region entirely covers the near IR telecommunications range. Although this effect is optimum at normal incidence and for a given polarization, rigorous theoretical and numerical calculations reveal that transparency is robust against changes in polarization and angle of incidence, and also holds for relatively dense periodic or random arrangements. A wealth of applications based on metal-NWs may benefit from such invisibility

    Nanostructural changes in cell wall pectins during strawberry fruit ripening assessed by atomic force microscopy

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    Rapid loss of firmness occurs during strawberry (Fragaria × ananassa Duch) ripening, resulting in a short shelf life and high economic losses. The disassembly of cell walls is considered the main responsible for fruit softening, being pectins extensively modified during strawberry ripening (Paniagua et al. 2014). Atomic force microscopy allows the analysis of individual polymer chains at nanostructural level with a minimal sample preparation (Morris et al., 2001). The main objective of this research was to compare pectins of green and red ripe strawberry fruits at the nanostructural level to shed light on structural changes that could be related to softening. Cell walls from strawberry fruits were extracted and fractionated with different solvents to obtain fractions enriched in a specific component. The yield of cell wall material, as well as the amount of the different fractions, decreased in ripe fruits. CDTA and Na2CO3 fractions underwent the largest decrements, being these fractions enriched in pectins supposedly located in the middle lamella and primary cell wall, respectively. Uronic acid content also decreased significantly during ripening in both pectin fractions, but the amount of soluble pectins, those extracted with phenol:acetic acid:water (PAW) and water increased in ripe fruits. Monosaccharide composition in CDTA and Na2CO3 fractions was determined by gas chromatography. In both pectin fractions, the amount of Ara and Gal, the two most abundant carbohydrates, decreased in ripe fruits. The nanostructural characteristics of CDTA and Na2CO3 pectins were analyzed by AFM. Isolated pectic chains present in the CDTA fraction were significantly longer and more branched in samples from green fruits than those present in samples obtained from red fruit. In spite of slight differences in length distributions, Na2CO3 samples from unripe fruits displayed some longer chains at low frequency that were not detected in ripe fruits. Pectin aggregates were more frequently observed in green fruit samples from both fractions. These results support that pectic chain length and the nanostructural complexity of the pectins present in CDTA and Na2CO3 fractions diminish during strawberry fruit development, and these changes, jointly with the loss of neutral sugars, could contribute to the solubilization of pectins and fruit softening. Paniagua et al. (2014). Ann Bot, 114: 1375-1383 Morris et al. (2001). Food Sci Tech 34: 3-10 This research was supported by FEDER EU Funds and the Ministerio de Educación y Ciencia of Spain (grant reference AGL2011-24814)Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
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