2,822 research outputs found

    Social pedagogy versus social work in a Swedish context

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    In Sweden there are several different professions that work within the welfare sector. Two of these are social pedagogues and socionoms. This article examines the similarities and differences between these professional fields by exploring four areas in more detail: education, the history of ideas and theory, research and practice. The results show that there are not only many differences but also some similarities. In practical work, social pedagogues and socionoms often work side by side and perform similar tasks. They are located in the same areas and often use the same methods. When it comes to the differences in educational history and current educations, they are large although they can also be found in, for example, the history of ideas. Furthermore, research in the various areas differs. In social pedagogy the interest has to a greater extent been focused on an understanding of the discipline through studies of the history of ideas, while in social work today one often focuses on studies of professional methods. Today’s challenges in the welfare sector require new knowledge, ways of thinking and understanding. Here, social pedagogy with its philosophical roots and humanistic values can play an important role

    Deconvolving Instrumental and Intrinsic Broadening in Excited State X-ray Spectroscopies

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    Intrinsic and experimental mechanisms frequently lead to broadening of spectral features in excited-state spectroscopies. For example, intrinsic broadening occurs in x-ray absorption spectroscopy (XAS) measurements of heavy elements where the core-hole lifetime is very short. On the other hand, nonresonant x-ray Raman scattering (XRS) and other energy loss measurements are more limited by instrumental resolution. Here, we demonstrate that the Richardson-Lucy (RL) iterative algorithm provides a robust method for deconvolving instrumental and intrinsic resolutions from typical XAS and XRS data. For the K-edge XAS of Ag, we find nearly complete removal of ~9.3 eV FWHM broadening from the combined effects of the short core-hole lifetime and instrumental resolution. We are also able to remove nearly all instrumental broadening in an XRS measurement of diamond, with the resulting improved spectrum comparing favorably with prior soft x-ray XAS measurements. We present a practical methodology for implementing the RL algorithm to these problems, emphasizing the importance of testing for stability of the deconvolution process against noise amplification, perturbations in the initial spectra, and uncertainties in the core-hole lifetime.Comment: 35 pages, 13 figure

    Solid State Switch Application for the LHC Extraction Kicker Pulse Generator

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    A semiconductor solid state switch has been constructed and tested in the prototype extraction kicker pulse generator of CERN's Large Hadron Collider (LHC) [1]. The switch is made of 10 modified 4.5 kV, 66 mm symmetric GTO's (also called FHCT-Fast High Current Thyristor), connected in series. It holds off a d.c. voltage of 30 kV and conducts a 5 µs half-sine wave current of 20 kA with an initial di/dt of 10 kA/µs. Major advantages of the switch are the extremely low self-firing hazard, no power consumption during the ready-to-go status, instantaneous availability, simple condition control, very low noise emission during soft turn-on switching and easy maintenance. However, the inherent soft, relatively slow turn-on time is a non negligible part of the required rise time and this involves adaptation of generator components. A dynamic current range of 16 is achieved with variations in rise time, which stay within acceptable limits. Important generator improvements have been made with the series diodes and freewheel diodes. A more efficient droop compensation circuit is being studied. It is directly connected in series with the freewheel diode stack and maintains an acceptable flattop variation of 5% of the magnet current during 90 µs. This paper presents the complete generator, in particular the solid state switch and discusses related electrical measurements

    Carbon release by selective alloying of transition metal carbides

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    We have performed first principles density functional theory calculations on TiC alloyed on the Ti sublattice with 3d transition metals ranging from Sc to Zn. The theory is accompanied with experimental investigations, both as regards materials synthesis as well as characterization. Our results show that by dissolving a metal with a weak ability to form carbides, the stability of the alloy is lowered and a driving force for the release of carbon from the carbide is created. During thin film growth of a metal carbide this effect will favor the formation of a nanocomposite with carbide grains in a carbon matrix. The choice of alloying elements as well as their concentrations will affect the relative amount of carbon in the carbide and in the carbon matrix. This can be used to design the structure of nanocomposites and their physical and chemical properties. One example of applications is as low-friction coatings. Of the materials studied, we suggest the late 3d transition metals as the most promising elements for this phenomenon, at least when alloying with TiC.Comment: 9 pages, 6 figure

    Symptoms and Stereotypes: Perceptions and Responses to Covid-19 in Malawi and Zambia

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    A large literature documents Covid-19’s health and economic effects. We focus instead on its political impact and its potential to exacerbate identity divisions, in particular. Psychologists argue that contagious disease increases threat perceptions and provokes policing of group boundaries. We explore how insider-outsider status and symptoms of illness shape perceptions of infection, reported willingness to help, and desire to restrict free movement of an ailing neighbor using a phone-based survey experiment administered three times in two neighboring African countries during different stages of the pandemic: Malawi, from May 5 to June 2, 2020 (n = 4,641); Zambia, from July 2 to August 13, 2020 (n = 2,198); and Malawi again, from March 9 to May 1, 2021 (n = 4,356). We study identities that are salient in Malawi and Zambia but have not induced significant prior violence, making our study a relatively hard test of disease threat theories. We find that symptoms more strongly shape perceptions and projected behavior than insider-outsider status in both countries and across time, suggesting that there are limits to the ability of pandemics to independently provoke identity politics de novo

    Osseous differentiation of human fat tissue grafts: From tissue engineering to tissue differentiation

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    Conventional bone tissue engineering approaches require isolation and in vitro propagation of autologous cells, followed by seeding on a variety of scaffolds. Those protracted procedures impede the clinical applications. Here we report the transdifferentiation of human fat tissue fragments retrieved from subcutaneous fat into tissue with bone characteristics in vitro without prior cell isolation and propagation. 3D collagen-I cultures of human fat tissue were cultivated either in growth medium or in osteogenic medium (OM) with or without addition of Bone Morphogenetic Proteins (BMPs) BMP-2, BMP-7 or BMP-9. Ca2+ depositions were observed after two weeks of osteogenic induction which visibly increased when either type of BMP was added. mRNA levels of alkaline phosphatase (ALP) and osteocalcin (OCN) increased when cultured in OM alone but addition of BMP-2, BMP-7 or BMP-9 caused significantly higher expression levels of ALP and OCN. Immunofluorescent staining for OCN, osteopontin and sclerostin supported the observed real-time-PCR data. BMP-9 was the most effective osteogenic inducer in this system. Our findings reveal that tissue regeneration can be remarkably simplified by omitting prior cell isolation and propagation, therefore removing significant obstacles on the way to clinical applications of much needed regeneration treatments

    Elections in the time of covid-19: the triple crises around Malawi’s 2020 presidential elections

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    In June 2020, in the midst of the Covid-19 pandemic, Malawians went to the polls and voted to replace the incumbent government. Much like other natural disasters, the Covid-19 pandemic and accompanying economic and political shocks had the potential to shake voters’ confidence in the government, reduce turnout, and/or reduce support for the incumbent if voters associated them with the ills of the pandemic. In this paper, we examine the extent to which the Coronavirus pandemic influenced Malawi’s 2020 elections. We consider how fear of infection and economic distress affected citizens’ trust and confidence in President Mutharika’s government, their willingness to turn out to vote, and their choices at the polls using data collected pre- and post-Covid. We find that fears about the virus and its economic impact did influence trust and confidence in the government to handle Covid but had little to no effect on either abstention or vote choice

    Mechanistic target of rapamycin complex 1 signaling links hypoxia to increased igfbp-1 phosphorylation in primary human decidualized endometrial stromal cells

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    Insulin-like growth factor-1 (IGF-1) bioavailability in pregnancy is governed by IGF binding protein (IGFBP-1) and its phosphorylation, which enhances the affinity of IGFBP-1 for the growth factor. The decidua is the predominant source of maternal IGFBP-1; however, the mechanisms regulating decidual IGFBP-1 secretion/phosphorylation are poorly understood. Using decidualized primary human endometrial stromal cells (HESCs) from first-trimester placenta, we tested the hypothesis that mTORC1 signaling mechanistically links hypoxia to decidual IGFBP-1 secretion/phosphorylation. Hypoxia inhibited mechanistic target of rapamycin (mTORC1) (p-P70-S6K/Thr389, −47%, p = 0.038; p-4E-BP1/Thr70, −55%, p = 0.012) and increased IGFBP-1 (total, +35%, p = 0.005; phosphorylated, Ser101/+82%, p = 0.018; Ser119/+88%, p = 0.039; Ser 169/+157%, p = 0.019). Targeted parallel reaction monitoring-mass spectrometry (PRM-MS) additionally demonstrated markedly increased dual IGFBP-1 phosphorylation (pSer98+Ser101; pSer169+Ser174) in hypoxia. IGFBP-1 hyperphosphorylation inhibited IGF-1 receptor autophosphorylation/ Tyr1135 (−29%, p = 0.002). Furthermore, silencing of tuberous sclerosis complex 2 (TSC2) activated mTORC1 (p-P70-S6K/Thr389, +68%, p = 0.038; p-4E-BP1/Thr70, +30%, p = 0.002) and reduced total/site-specific IGFBP-1 phosphorylation. Importantly, TSC2 siRNA prevented inhibition of mTORC1 and the increase in secretion/site-specific IGFBP-1 phosphorylation in hypoxia. PRM-MS indicated concomitant changes in protein kinase autophosphorylation (CK2/Tyr182; PKC/Thr497; PKC/Ser657). Overall, mTORC1 signaling mechanistically links hypoxia to IGFBP-1 secretion/phosphorylation in primary HESC, implicating decidual mTORC1 inhibition as a novel mechanism linking uteroplacental hypoxia to fetal growth restriction
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