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  • 251. Abdollahi, Abbas
    et al.
    Carlbring, Per
    Stockholm University, Faculty of Social Sciences, Department of Psychology, Clinical psychology.
    Khanbani, Mehdi
    Abdollahi Ghahfarokhi, Shahyar
    Emotional intelligence moderates perceived stress and suicidal ideation among depressed adolescent inpatients2016In: Personality and Individual Differences, ISSN 0191-8869, E-ISSN 1873-3549, Vol. 102, p. 223-228Article in journal (Refereed)
    Abstract [en]

    Because it remains one of the third leading causes of death among adolescents around the world, suicide is a major public health concern. This study was designed in response to this concern by examining the relationships among perceived stress, emotional intelligence, and suicidal ideation and to test the moderating role of emotional intelligence in the relationship between perceived stress and suicidal ideation. A sample of depressed adolescents (n = 202) was recruited from five hospitals in Tehran, Iran, and then asked to complete measures of patient health, suicidal ideation, perceived stress, and emotional intelligence. Structural Equation Modeling showed that depressed adolescent in-patients with high levels of perceived stress and low levels of emotional intelligence were more likely to report suicidal ideation. Multi-group analysis indicated that depressed in-patients high in both perceived stress and emotional intelligence had less suicidal ideation than others. The findings support the notion that perceived stress acts as a vulnerability factor that increase suicidal ideation among depressed inpatients. Suicidal history moderated the relationship between emotional intelligence and suicidal ideation. These findings also highlight the importance of emotional intelligence as a buffer in the relationship between perceived stress and suicidal ideation.

  • 252. Abdollahi, Abbas
    et al.
    Carlbring, Per
    Stockholm University, Faculty of Social Sciences, Department of Psychology, Clinical psychology.
    Vaez, Elham
    Abdollahi Ghahfarokhi, Shahyar
    Perfectionism and Test Anxiety among High-School Students: the Moderating Role of Academic Hardiness2018In: Current psychology (New Brunswick, N.J.), ISSN 1046-1310, E-ISSN 1936-4733, Vol. 37, no 3, p. 632-639Article in journal (Refereed)
    Abstract [en]

    Recent evidence suggests that test anxiety is increasing among students; however, relatively little is known regarding the related factors of test anxiety. The purpose of this study was to (1) examine the relationships between two forms of perfectionism, academic hardiness, and test anxiety, and (2) examine the moderating role of academic hardiness on the association between two types of perfectionism and test anxiety. This study included 520 students ranging from 15 to 21 years of age from eight high schools in Tehran, Iran completed the self-administered questionnaires. The results of Structural Equation Modelling (SEM) revealed that students with high levels of personal standards perfectionism and high levels of academic hardiness were less likely to experience test anxiety, while students with high levels of evaluative concerns perfectionism were more likely to experience test anxiety. A multi-group analysis revealed that academic hardiness moderated the relationship between evaluative concerns perfectionism and test anxiety. These findings enhance existing literature by revealing moderating processes that explain how perfectionism effects test anxiety.

  • 253. Abdollahi, Abbas
    et al.
    Hosseinian, Simin
    Beh-Pajooh, Ahmad
    Carlbring, Per
    Stockholm University, Faculty of Social Sciences, Department of Psychology, Clinical psychology.
    Self-Concealment Mediates the Relationship Between Perfectionism and Attitudes Toward Seeking Psychological Help Among Adolescents2017In: Psychological Reports, ISSN 0033-2941, E-ISSN 1558-691X, Vol. 120, no 6, p. 1019-1036Article in journal (Refereed)
    Abstract [en]

    One of the biggest barriers in treating adolescents with mental health problems is their refusing to seek psychological help. This study was designed to examine the relationships between two forms of perfectionism, self-concealment and attitudes toward seeking psychological help and to test the mediating role of self-concealment in the relationship between perfectionism and attitudes toward seeking psychological help among Malaysian high school students. The participants were 475 Malaysian high school students from four high schools in Kuala Lumpur, Malaysia. Structural equation modelling results indicated that high school students with high levels of socially prescribed perfectionism, high levels of self-concealment, and low levels of self-oriented perfectionism reported negative attitudes toward seeking psychological help. Bootstrapping analysis showed that self-concealment emerged as a significant, full mediator in the link between socially prescribed perfectionism and attitudes toward seeking psychological help. Moderated mediation analysis also examined whether the results generalized across men and women. The results revealed that male students with socially prescribed perfectionism are more likely to engage in self-concealment, which in turn, leads to negative attitudes toward seeking psychological help more than their female counterparts. The results suggested that students high in socially prescribed perfectionism were more likely to engage in self-concealment and be less inclined to seek psychological help.

  • 254. Abdollahi, Abbas
    et al.
    Hosseinian, Simin
    Zamanshoar, Elham
    Beh-Pajooh, Ahmad
    Carlbring, Per
    Stockholm University, Faculty of Social Sciences, Department of Psychology, Clinical psychology.
    The Moderating Effect of Hardiness on the Relationships between Problem-Solving Skills and Perceived Stress with Suicidal Ideation in Nursing Students2018In: Studia psychologica (Bratislava), ISSN 0039-3320, Vol. 60, no 1, p. 30-41Article in journal (Refereed)
    Abstract [en]

    Recent evidence indicates an elevated risk of suicidal ideation for undergraduate nursing students. This research was designed to enhance the understanding of suicidal ideation in nursing students by investigating the relationships between problem-solving skills, perceived stress, hardiness, and suicidal ideation, with the possibility of hardiness acting as a moderator in the relationships between problem-solving skills appraisal and perceived stress with suicidal ideation. A multi-stage cluster random sample of Malaysian nursing undergraduate students (N = 204) completed self-report questionnaires. The results of structural equation modeling revealed that poor problem-solving skills, greater levels of perceived stress, and low levels of hardiness predicted greater levels of suicidal ideation. Also, hardiness emerged as a moderator in the links between problem-solving skills appraisal and perceived stress with suicidal ideation. The findings incrementally improve our understanding about the importance of hardiness as a moderator in explaining how problem-solving skills and perceived stress affect suicidal ideation. The results of this study are obtained from Malaysian nursing students and possible generalization to other populations should be verified by further studies.

  • 255. Abdollahi, Abbas
    et al.
    LeBouthillier, Daniel M.
    Najafi, Mahmoud
    Asmundson, Gordon J. G.
    Hosseinian, Simin
    Shahidi, Shahriar
    Carlbring, Per
    Stockholm University, Faculty of Social Sciences, Department of Psychology, Clinical psychology.
    Kalhori, Atefeh
    Sadeghi, Hassan
    Jalili, Marzieh
    Effect of exercise augmentation of cognitive behavioural therapy for the treatment of suicidal ideation and depression2017In: Journal of Affective Disorders, ISSN 0165-0327, E-ISSN 1573-2517, Vol. 219, p. 58-63Article in journal (Refereed)
    Abstract [en]

    Background: Suicidal ideation and depression are prevalent and costly conditions that reduce quality of life. This study was designed to determine the efficacy of exercise as an adjunct to cognitive behavioural therapy (CBT) for suicidal ideation and depression among depressed individuals.

    Methods: In a randomized clinical trial, 54 mildly to moderately depressed patients (54% female, mean age=48.25) were assigned to a combined CBT and exercise group or to a CBT only group. Both groups received one weekly session of therapy for 12 weeks, while the combined group also completed exercise three times weekly over the same period. Self-reported suicidal ideation, depression, and activities of daily living were measured at the beginning and the end of treatment.

    Results: Multilevel modelling revealed greater improvements in suicidal ideation, depression, and activities of daily living in the combined CBT and exercise group, compared to the CBT only group.

    Limitations: No follow-up data were collected, so the long-term effects (i.e., maintenance of gains) is unclear.

    Conclusions: The findings revealed that exercise adjunct to CBT effectively decreases both depressive symptoms and suicidal ideation in mildly to moderately depressed individuals.

  • 256. Abdollahi, S.
    et al.
    Ackermann, M.
    Ajello, M.
    Albert, A.
    Baldini, L.
    Ballet, J.
    Barbiellini, G.
    Bastieri, D.
    Becerra Gonzalez, J.
    Bellazzini, R.
    Bissaldi, E.
    Blandford, R. D.
    Bloom, E. D.
    Bonino, R.
    Bottacini, E.
    Bregeon, J.
    Bruel, P.
    Buehler, R.
    Buson, S.
    Cameron, R. A.
    Caragiulo, M.
    Caraveo, P. A.
    Cavazzuti, E.
    Cecchi, C.
    Chekhtman, A.
    Cheung, C. C.
    Chiaro, G.
    Ciprini, S.
    Conrad, Jan
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Costantin, D.
    Costanza, F.
    Cutini, S.
    D'Ammando, F.
    de Palma, F.
    Desai, A.
    Desiante, R.
    Digel, S. W.
    Di Lalla, N.
    Di Mauro, M.
    Di Venere, L.
    Donaggio, B.
    Drell, P. S.
    Favuzzi, C.
    Fegan, S. J.
    Ferrara, E. C.
    Focke, W. B.
    Franckowiak, A.
    Fukazawa, Y.
    Funk, S.
    Fusco, P.
    Gargano, F.
    Gasparrini, D.
    Giglietto, N.
    Giomi, M.
    Giordano, F.
    Giroletti, M.
    Glanzman, T.
    Green, D.
    Grenier, I. A.
    Grove, J. E.
    Guillemot, L.
    Guiriec, S.
    Hays, E.
    Horan, D.
    Jogler, T.
    Johannesson, G.
    Johnson, A. S.
    Kocevski, D.
    Kuss, M.
    La Mura, G.
    Larsson, S.
    Latronico, L.
    Li, J.
    Longo, F.
    Loparco, F.
    Lovellette, M. N.
    Lubrano, P.
    Magill, J. D.
    Maldera, S.
    Manfreda, A.
    Mayer, M.
    Mazziotta, M. N.
    Michelson, P. F.
    Mitthumsiri, W.
    Mizuno, T.
    Monzani, M. E.
    Morselli, A.
    Moskalenko, I. V.
    Negro, M.
    Nuss, E.
    Ohsugi, T.
    Omodei, N.
    Orienti, M.
    Orlando, E.
    Paliya, V. S.
    Paneque, D.
    Perkins, J. S.
    Persic, M.
    Pesce-Rollins, M.
    Petrosian, V.
    Piron, F.
    Porter, T. A.
    Principe, G.
    Raino, S.
    Rando, R.
    Razzano, M.
    Razzaque, S.
    Reimer, A.
    Reimer, O.
    Sgro, C.
    Simone, D.
    Siskind, E. J.
    Spada, F.
    Spandre, G.
    Spinelli, P.
    Stawarz, L.
    Suson, D. J.
    Takahashi, M.
    Tanaka, K.
    Thayer, J. B.
    Thompson, D. J.
    Torres, D. F.
    Torresi, E.
    Tosti, G.
    Troja, E.
    Vianello, G.
    Wood, K. S.
    The Second Catalog of Flaring Gamma-Ray Sources from the Fermi All-sky Variability Analysis2017In: Astrophysical Journal, ISSN 0004-637X, E-ISSN 1538-4357, Vol. 846, no 1, article id 34Article in journal (Refereed)
    Abstract [en]

    We present the second catalog of flaring gamma-ray sources (2FAV) detected with the Fermi All-sky Variability Analysis (FAVA), a tool that blindly searches for transients over the entire sky observed by the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope. With respect to the first FAVA catalog, this catalog benefits from a larger data set, the latest LAT data release (Pass 8), as well as from an improved analysis that includes likelihood techniques for a more precise localization of the transients. Applying this analysis to the first 7.4 years of Fermi observations, and in two separate energy bands 0.1-0.8 GeV and 0.8-300 GeV, a total of 4547 flares were detected with significance greater than 6s (before trials), on the timescale of one week. Through spatial clustering of these flares, 518 variable gamma-ray sources were identified. Based on positional coincidence, likely counterparts have been found for 441 sources, mostly among the blazar class of active galactic nuclei. For 77 2FAV sources, no likely gamma-ray counterpart has been found. For each source in the catalog, we provide the time, location, and spectrum of each flaring episode. Studying the spectra of the flares, we observe a harder-when-brighter behavior for flares associated with blazars, with the exception of BL Lac flares detected in the low-energy band. The photon indexes of the flares are never significantly smaller than 1.5. For a leptonic model, and under the assumption of isotropy, this limit suggests that the spectrum of freshly accelerated electrons is never harder than p similar to 2.

  • 257. Abdollahi, S.
    et al.
    Ackermann, M.
    Ajello, M.
    Atwood, W. B.
    Baldini, L.
    Ballet, J.
    Barbiellini, G.
    Bastieri, D.
    Gonzalez, J. Becerra
    Bellazzini, R.
    Bissaldi, E.
    Blandford, R. D.
    Bloom, E. D.
    Bonino, R.
    Bottacini, E.
    Buson, S.
    Bregeon, J.
    Bruel, P.
    Buehler, R.
    Cameron, R. A.
    Caputo, R.
    Caraveo, P. A.
    Cavazzuti, E.
    Charles, E.
    Chen, S.
    Cheung, C. C.
    Chiaro, G.
    Ciprini, S.
    Cohen-Tanugi, J.
    Cominsky, L. R.
    Conrad, Jan
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Costantin, D.
    Cutini, S.
    D'Ammando, F.
    de Palma, F.
    Desai, A.
    Digel, S. W.
    Di Lalla, N.
    Di Mauro, M.
    Di Venere, L.
    Dominguez, A.
    Favuzzi, C.
    Fegan, S. J.
    Finke, J.
    Franckowiak, A.
    Fukazawa, Y.
    Funk, S.
    Fusco, P.
    Romero, G. Gallardo
    Gargano, F.
    Gasparrini, D.
    Giglietto, N.
    Giordano, F.
    Giroletti, M.
    Green, D.
    Grenier, I. A.
    Guillemot, L.
    Guiriec, S.
    Hartmann, D. H.
    Hays, E.
    Helgason, K.
    Horan, D.
    Johannesson, G.
    Kocevski, D.
    Kuss, M.
    Larsson, S.
    Latronico, L.
    Li, J.
    Longo, F.
    Loparco, F.
    Lott, B.
    Lovellette, M. N.
    Lubrano, P.
    Madejski, G. M.
    Magill, J. D.
    Maldera, S.
    Manfreda, A.
    Marcotulli, L.
    Mazziotta, M. N.
    McEnery, J. E.
    Meyer, M.
    Michelson, P. F.
    Mizuno, T.
    Monzani, M. E.
    Morselli, A.
    Moskalenko, I. V.
    Negro, M.
    Nuss, E.
    Ojha, R.
    Omodei, N.
    Orienti, M.
    Orlando, E.
    Ormes, J. F.
    Palatiello, M.
    Paliya, V. S.
    Paneque, D.
    Perkins, J. S.
    Persic, M.
    Pesce-Rollins, M.
    Petrosian, V.
    Piron, F.
    Porter, T. A.
    Primack, J. R.
    Principe, G.
    Raino, S.
    Rando, R.
    Razzano, M.
    Razzaque, S.
    Reimer, A.
    Reimer, O.
    Parkinson, P. M. Saz
    Sgro, C.
    Siskind, E. J.
    Spandre, G.
    Spinelli, P.
    Suson, D. J.
    Tajima, H.
    Takahashi, M.
    Thayer, J. B.
    Tibaldo, L.
    Torres, D. F.
    Torresi, E.
    Tosti, G.
    Tramacere, A.
    Troja, E.
    Valverde, J.
    Vianello, G.
    Vogel, M.
    Wood, K.
    Zaharijas, G.
    A gamma-ray determination of the Universe's star formation history2018In: Science, ISSN 0036-8075, E-ISSN 1095-9203, Vol. 362, no 6418, p. 1031-1034Article in journal (Refereed)
    Abstract [en]

    The light emitted by all galaxies over the history of the Universe produces the extragalactic background light (EBL) at ultraviolet, optical, and infrared wavelengths. The EBL is a source of opacity for gamma rays via photon-photon interactions, leaving an imprint in the spectra of distant gamma-ray sources. We measured this attenuation using 739 active galaxies and one gamma-ray burst detected by the Fermi Large Area Telescope. This allowed us to reconstruct the evolution of the EBL and determine the star formation history of the Universe over 90% of cosmic time. Our star formation history is consistent with independent measurements from galaxy surveys, peaking at redshift z similar to 2. Upper limits of the EBL at the epoch of reionization suggest a turnover in the abundance of faint galaxies at z similar to 6.

  • 258.
    Abdollahian Barough, Somaje
    Stockholm University, Faculty of Humanities, Department of English.
    Event conceptualisation and aspect in L2 English and Persian: An application of the Heidelberg–Paris model2019Doctoral thesis, monograph (Other academic)
    Abstract [en]

    The present project investigates the impact of the grammaticalised progressive on event conceptualisation in English and Persian. It applies the Heidelberg–Paris framework using single event descriptions for analysis at the sentence level and story re-narrations at the discourse level. The empirical data test the hypothesis that the progressive has an impact on information selection and discourse structuring in event conceptualisation in terms of infrequent endpoint encodings and language-specific patterns of perspective-taking in structuring discourse. Languages lacking the grammaticalised progressive clearly show different effects.

    There are system-based similarities/differences in aspect between English and Persian. They have the progressive in common but differ with respect to the imperfective-perfective distinction. This difference is manifested as an increase in the use of the progressive in English. In contrast, the Persian system with two aspectual non-past forms which are possible for expressions of ongoingness leads to decreased use of the particular dāštan-progressive.

    The key finding for the single, motion event descriptions is that the dāštan-progressive in Persian shows less frequent endpoint encodings, like in English, as compared to languages lacking the progressive. However, the imperfective bare mi-form is associated with frequent endpoints while English shows no such association because the progressive must always be used.

    In narratives, differences emerge again due to the different typology. When the uses of the progressives in re-narrations are differentiated for clause type, the progressive in English is used equally in main and sub-clauses, though more dominantly in sub-clauses in Persian. These sub-results speak about differences in perspective-taking between these L1s.

    The analysis of the complexities involved in aspect establishes that the bare mi-form in Persian can denote ongoingness in cases where the progressive is obligatory in English as it has no optional verb form. Consequently, the typological difference of the absence/presence of the imperfective-perfective categories leads to a significant increase in the use of the progressive in English, which results in a cross-linguistically different, and L1-specific, patterns of perspective-taking in the narrative discourse in English and Persian. Thus, despite the fact that the L1s have the progressive aspect, their principles of use differ as they are dependent on the relevant aspectual system.

    Relating the results to linguistic relativity and cross-linguistic influence, the study shows that owing to the grammatical category of the progressive in common, event conceptualisation is similar in English and Persian in terms of infrequent endpoint encodings in single motion event descriptions, despite the overall typological difference. However, L1-related influence on the principles of use of the progressive in L2 English is considerable in the narrative discourse of the advanced L2 users of English as they seemingly proceed from the principles of use in L1 Persian towards those in L1 English.

  • 259.
    Abdollahian Barough, Somaje
    Stockholm University, Faculty of Humanities, Department of English.
    Reflections on Persian Grammar Developments in Persian Linguistic Scholarship I2017Other (Other academic)
  • 260.
    Abdollahian, Somaje
    Stockholm University, Faculty of Humanities, Department of English.
    Perspectivation in narratives in Persian L2 English2011In: EUROSLA 21, 21st Annual Conference of the European Second Language Association, Stockholm University, 8-10 September 2011: Book of Abstracts, 2011, p. 216-216Conference paper (Refereed)
  • 261. Abdou, Y.
    et al.
    Becker, K. -H
    Berdermann, J.
    Bissok, M.
    Bohm, Christian
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Boeser, S.
    Bothe, M.
    Carson, M.
    Descamps, F.
    Fischer-Wolfarth, J. -H
    Gustafsson, L.
    Hallgren, A.
    Heinen, D.
    Helbing, K.
    Heller, R.
    Hundertmark, S.
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Karg, T.
    Krieger, K.
    Laihem, K.
    Meures, T.
    Nahnhauer, R.
    Naumann, U.
    Oberson, F.
    Paul, L.
    Pohl, M.
    Price, B.
    Ribordy, M.
    Ryckbosch, D.
    Schunck, M.
    Semburg, B.
    Stegmaier, J.
    Sulanke, K. -H
    Tosi, D.
    Vandenbroucke, J.
    Wiebusch, C.
    Design and performance of the South Pole Acoustic Test Setup2012In: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, ISSN 0168-9002, E-ISSN 1872-9576, Vol. 683, p. 78-90Article in journal (Refereed)
    Abstract [en]

    The South Pole Acoustic Test Setup (SPATS) was built to evaluate the acoustic characteristics of the South Pole ice in the 10-100 kHz frequency range, for the purpose of assessing the feasibility of an acoustic neutrino detection array at the South Pole. The SPATS hardware consists of four vertical strings deployed in the upper 500 m of the South Pole ice cap. The strings form a trapezoidal array with a maximum baseline of 543 m. Each string has seven stages equipped with one transmitter and one sensor module (glaciophone). Sound is detected or generated by piezoelectric ceramic elements inside the modules. Analogue signals are sent to the surface on electric cables where they are digitized by a PC-based data acquisition system. The data from all strings are collected on a central computer in the IceCube Laboratory from where they are sent to a central data storage facility via a satellite link or stored locally on tape. A technical overview of SPATS and its performance is presented.

  • 262.
    Abdul Baten, Mohammed
    Stockholm University, Stockholm Resilience Centre.
    Property rights in mangroves: A case study of the Mahakam Delta, East Kalimantan, Indonesia2009Independent thesis Advanced level (degree of Master (Two Years)), 40 credits / 60 HE creditsStudent thesis
    Abstract [en]

    Mangroves represent an important source of livelihood for many poor people acrossthe world. However, insufficient policy responses relating to mangrove conservation,combined with the lack of clearly defined property rights contribute extensively to theconversion of mangroves to alternative uses, in particular shrimp aquaculture. On thebasis of relevant theoretical perspectives on property rights, this Master’s thesisanalyses various formal and informal institutions and existing governancemechanisms that determine natural resources management in the Mahakam delta, EastKalimantan, Indonesia. By employing a qualitative participatory research approachthe case study explores how different institutions in Indonesia shape the local propertyrights regime in mangroves. The results show that the interplay between formal andinformal institutions involved in defining property rights, along with the lack ofcoordination among responsible government agencies, has resulted in the clearing ofone of the largest Nypah forests in the world for shrimp pond construction withinthree decades. Moreover, the study suggests that the current problem of mangrovedestruction will not be solved merely by declaring the Mahakam delta as a protectedarea or by assigning full ownership rights to the local people. On the contrary, thestudy suggests that the coordination and enforcement mechanisms should be enhancedin such ways that they simultaneously address both local peoples’ needs as well asecosystem integrity.

  • 263.
    Abdul Nabi, Sarmad
    Stockholm University, Faculty of Law, Department of Law.
    Smart Contracts som ersättare för formalavtal2019Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Formkrav i svensk avtalsrätt innebär bl.a. att vissa avtal måste tecknas i skriftlig form och att de ska undertecknas på papper. I och med digitaliseringen har dock elektroniska medel för ingående av avtal blivit mer och mer av en norm. Smart Contracts är avtal som med tekniska medel syftar till automatisera parternas avtalsprestationer och därmed göra det säkrare för parter att ingå avtal. Detta arbete syftar därmed till att utvärdera huruvida användandet av avtal som ingås via den tekniska företeelsen Smart Contracts kan ersätta användandet av formalavtal.

  • 264.
    Abdulahi, Adan
    Stockholm University, Faculty of Social Sciences, School of Business.
    Invandrarföretagares möjlighet till ekonomiskt stöd från statliga institutioner2005Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Vid slutet av 80-talet ökade invandringen till Sverige samtidigt som dess karaktär förändrades. Idag pratar man om flyktinginvandring till skillnad från 80-talet då arbetskraftsinvandring dominerade de invandrare som fanns i Sverige. Det har blivit svårare för invandrare som kom till Sverige som flyktingar att integrera sig eftersom det råder hög arbetslöshet.

  • 265.
    Abduljebar, Semiha
    Stockholm University, Faculty of Social Sciences, Department of Child and Youth Studies.
    Matematik i förskolan: En studie om yngre barns matematik utifrån ett sociokulturellt perspektiv2017Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
  • 266.
    Abdulla, Alli
    Stockholm University, Faculty of Law, Department of Law.
    Expertskatt: en problemorienterad genomgång2014Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
  • 267.
    Abdulla, Tavga
    Stockholm University, Faculty of Science, Department of Mathematics and Science Education.
    Nyanlända elevers svårigheter i algebra: En studie om nyanlända elevers uppfattningar om undervisning i algebra samt textuppgifter inom algebra i introduktionsprogram2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Syftet med denna studie är att undersöka vilka matematiska och språkliga svårigheter nyanlända gymnasieelever har när de arbetar med algebra, både deras uppfattningar om undervisning i algebra och hur de löser textuppgifter inom algebra. Samtliga elever i studien är nyanlända och går ett introduktionsprogram och de har ett annat modersmål än svenska.

    Flera studier visar på att elever som har ett annat modersmålspråk än svenska har svårare att klara matematik i skolan och därmed presterar sämre i matematikundervisningen än andra elever som har svenska som modersmål (Malmer, 2002). I denna studie undersöks vad detta beror på och hur undervisningen kan anpassas för att bättre gynna den berörda elevgruppen.

    För att besvara frågeställningarna gjordes elevintervjuer med åtta elever samt ett test i algebra med eleverna som deltog i intervjuerna. Resultaten i denna studie visar på att eleverna hade språkliga svårigheter som påverkade deras problemlösningsförmåga i algebra. En orsak till detta är språkliga svårigheter och detta kan delvis bero på bristfälliga svenskkunskaper som leder till svårigheter att förstå textuppgifter och svårigheter att uttrycka sig när man kommunicerar inom matematik.

  • 268.
    Abdulla, Trifa
    Stockholm University, Faculty of Humanities, Department of Media Studies.
    De som avvek och en som gick in2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    I mitt reportage De som avvek och en som gick in berättar krigsvägraren William Males, desertören Steve David Kinnaman och veteranen Bill Ray i porträttform om hur de på olika sätt undkom kriget som rasade i Vietnam mellan åren 1955-1975.

    En vägrade i initialt skede att delta i kriget. En var halvvägs till Vietnam innan han avvek. Den tredje upplevde krigets fasor och överlevde. Gemensamt för dem alla är att Sverige blev deras andra hem från 1960-talet och framåt, en fristad undan kriget och hemlandet USAs politiska förföljelser.

    Utifrån ett dussin intervjuer, arkivmaterial, facklitteratur, gamla tidningsdokument, fotografier, ljudsnuttar, filmer och digitala källor har jag skrivit reportaget i tre självständiga porträtt. Tillsammans med nytagna porträttbilder av intervjupersonerna och privata fotografier från deras ungdomstid, flyktväg, krigsminnen och familjer har jag försökt skapa en så levande bild av deras liv som möjligt.

  • 269. Abdullah, Ailin
    et al.
    Berglund, Jenny
    Stockholm University, Faculty of Humanities, Department of Humanities and Social Sciences Education.
    State Neutrality and Islamic Education in Sweden2018In: European Perspectives on Islamic education and Public Schooling / [ed] Jenny Berglund, Sheffield, UK: Equinox Publishing, 2018, p. 312-334Chapter in book (Refereed)
    Abstract [en]

    Public debate about Islam and Muslims often focuses on contradictions, conflicts, and contrasting value systems. Since 9/11, the bombings in Madrid and London and the recent rise of ISIS this debate has to a large extent included a fear that Muslim immigrants will be disloyal to their new Western countries, and thus requires increased surveillance and control. Conversely, others argue that Muslim populations in the West have wrongly suffered from the increasing intolerance and suspicion resulting from terrorist acts committed by a small number of radicals. Such voices point to a need to safeguard religious freedom and the right to equal treatment regardless of a group’s ethnic, cultural, linguistic, or religious background. In many European countries, these discussions have directed attention toward places of Islamic education such as Muslim schools, mosques, and Islamic organizations, focusing on the sometimes controversial manner in which they have been depicted in the media, public discourse, and, within Muslim communities themselves (Aslan 2009; Birt 2006). Religious education is both an essential and a challenging objective for minorities since the “transmission” of religious tradition to future generations is crucial to the survival of any religion. In Sweden as elsewhere in Europe many Muslim children and teenagers and even adults attend privately-run, extra-curricular Islamic classes. Some attend Islamic schools or are taught at home. Publically funded Islamic education options provided by the state are an emergent option in several European countries. These classes lie not only at the heart of debates over religious freedom, equal rights to education, and integration, but are also connected to matters of securitization and the state control of Islam. This paper will present an overview of publicly funded, mainly pre-university Islamic education in Sweden, a European Western secular Christian majority country with a Muslim minority population. Firstly, I will establish a definition of Islamic education and a description of the state funding of education and religion in general. Then, the paper will move on to describe different types of Islamic education that are available in Sweden.

  • 270.
    Abdullah, Anas
    Stockholm University, Faculty of Social Sciences, Department of Social Work.
    PRO i Österåkers kommun: en studie över PRO: s roll inom äldreomsorgen2005Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Syftet med denna c-uppsats har varit att kartlägga Pensionärernas riksorganisations (PRO) roll inom äldreomsorgen i Österåkers kommun. I vilket avseende PRO är ett komplement eller en ersättning till kommunens verksamhet. Den här studien faller under kvalitativ forskning och bygger enbart på skriftligt underlag. Materialet är PRO: s mål, handlingsprogram på riksnivå och verksamhetsberättelse 2004 för Österåkers kommun och kommunens mål, riktlinjer och verksamhetsberättelse 2004. Studien har visat att frivilliga organisationer i nästan alla under-sökningar man har gjort har haft en stark roll inom den offentliga sektorn. Även från politiskt håll har man också velat att dessa organisationer ska sköta en del av kommunens verksamhet. Studien har också visat genom resultatet och analysen att PRO som frivilligorganisation i Ös-teråkers kommun varken är ett komplement eller en ersättning till kommunens verksamhet. Däremot har PRO en roll som kooptering d.v.s. att de kan påverka beslut som berör äldre människor genom sin plats i pensionärsrådet.

  • 271. Abdullah, Omed Gh.
    et al.
    Tahir, Dana A.
    Kadir, K.
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK). Kurdistan Institution for Strategic Studies and Scientific Research, Iraq.
    Optical and structural investigation of synthesized PVA/PbS nanocomposites2015In: Journal of materials science. Materials in electronics, ISSN 0957-4522, E-ISSN 1573-482X, Vol. 26, no 9, p. 6939-6944Article in journal (Refereed)
    Abstract [en]

    Polymer nanocomposite based on polyvinyl alcohol (PVA) and lead sulfide (PbS) in the average radius of (1.88-2.23) nm, have been synthesized using the chemical reduction rote and solution casting technique for different concentrations of PbS. The characterization of the polymer nanocomposite films were carried out using UV-visible spectroscopy, SEM, and XRD. The effect of various concentration of PbS NP on the optical properties of the composite has been studied to understand the optimum conditions for the synthesis process. The nanocomposite film shows high UV and visible light absorptions in the wavelength range of (200-500) nm, which correspond to the characteristics of the PbS NPs. The significant decreasing trend of the direct allowed band gap of the nanocomposite was observed upon increasing the Pb source concentration, from (6.27 eV) for pure PVA to (2.34 eV) for 0.04 M PbS concentration, which is much higher than the energy gap of bulk PbS value (0.41 eV). The calculated values of the static refractive index of Cauchy dispersion model were in the range of (1.09-1.20). X-ray diffraction analysis confirmed the cubic nanocrystalline PbS phase formation.

  • 272.
    Abdulrahim, Jihan
    Stockholm University, Faculty of Social Sciences, Department of Sociology.
    Kvinnors politiska deltagande i irakiska Kurdistan: en kvantitativ studie2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Syftet med denna studie är att undersöka kvinnors politiska deltagande i irakiska Kurdistan. utifrån syftet undersökt sex frågeställningar: Hur stor andel av kvinnorna i irakiska Kurdistan röstade i förra valet, är medlemmar i ett politiskt parti, arbetar i ett politiskt parti, har kontaktat en politiker eller deltagit i en manifestation, vad kvinnor själva anser vara vilka faktorer som hindrar deras politiska deltagande samt om det finns ett samband mellan utbildning och kvinnors politiska deltagande. En enkätundersökning genomfördes i irakiska Kurdistan. Arbil, Dohuk och slemaniya, sammanlagt mottogs 200 enkäter. Resultaten visar att det politiska deltagande är högt bland de undersökta kvinnorna i alla deltagandeformerna. Det finns inget samband mellan utbildning och kvinnors politiska deltagande i urvalet. Få av kvinnorna uppgav att kulturella eller religiösa normer är ett hinder för deras politiska deltagande. Den vanligaste rapporterade orsaken till att inte delta var ointresse för att engagera sig i politiken eller otillräckligt kunskap. Dessa resultat skiljer sig från forskning som har visat att kvinnor i Mellanöstern deltar i politiken i liten utsträckning. 

  • 273.
    Abebaw, Tilahun
    Stockholm University, Faculty of Science, Department of Mathematics. Matematik.
    On the decomposition of D-modules over a hyperplane arrangement2007Licentiate thesis, monograph (Other academic)
  • 274.
    Abebaw, Tilahun
    et al.
    Stockholm University, Faculty of Science, Department of Mathematics.
    Bogvad, Rikard
    Stockholm University, Faculty of Science, Department of Mathematics.
    Decomposition of D-modules over a hyperplane arrangement in the plane2010In: Arkiv för matematik, ISSN 0004-2080, E-ISSN 1871-2487, Vol. 48, no 2, p. 211-229Article in journal (Refereed)
    Abstract [en]

    Let alpha(1), alpha(2),..., alpha(m) be linear forms defined on C-n and X = C-n\boolean OR(m)(i=1) V(alpha(i)), where V(alpha(i))={p is an element of C-n : alpha(i)(p)=0}. The coordinate ring O-X of X is a holonomic A(n)-module, where A(n) is the nth Weyl algebra and since holonomic A(n)-modules have finite length, O-X has finite length. We consider a "" twisted"" variant of this An- module which is also holonomic. Define M-alpha(beta) to be the free rank-1 C[x](alpha)-module on the generator alpha(beta) (thought of as a multivalued function), where alpha(beta)=alpha(beta 1)(1),..., alpha(beta m)(m) and the multi-index beta=(beta(1),...,beta(m))is an element of C-m. Our main result is the computation of the number of decomposition factors of M-alpha(beta) and their description when n-2.

  • 275.
    Abebaw, Tilahun
    et al.
    Stockholm University, Faculty of Science, Department of Mathematics. Addis Ababa University, Ethiopia.
    Bøgvad, Rikard
    Stockholm University, Faculty of Science, Department of Mathematics.
    Decomposition factors of D-modules on hyperplane configurations in general position2012In: Proceedings of the American Mathematical Society, ISSN 0002-9939, E-ISSN 1088-6826, Vol. 140, no 8, p. 2699-2711Article in journal (Refereed)
    Abstract [en]

    Let alpha(1), ... , alpha(m) be linear functions on C-n and X = C-n \ V(alpha), where alpha = Pi(m)(i=1) alpha(i) and V(alpha) = {p is an element of C-n : alpha(p) = 0}. The coordinate ring O-X = C[x](alpha) of X is a holonomic A(n)-module, where A(n) is the n-th Weyl algebra, and since holonomic A(n)-modules have finite length, O-X has finite length. We consider a twisted variant of this A(n)-module which is also holonomic. Define M-alpha(beta) to be the free rank 1 C[x](alpha)-module on the generator alpha(beta) (thought of as a multivalued function), where alpha(beta) = alpha(beta 1)(1) ... alpha(beta m)(m) and the multi-index beta = (beta(1), ... , beta(m)) is an element of C-m. It is straightforward to describe the decomposition factors of M-alpha(beta), when the linear functions alpha(1), ... , alpha(m) define a normal crossing hyperplane configuration, and we use this to give a sufficient criterion on beta for the irreducibility of M-alpha(beta), in terms of numerical data for a resolution of the singularities of V(alpha).

  • 276.
    Abebe, Mihret
    et al.
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Hedin, Niklas
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Bacsik, Zoltan
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Spherical and Porous Particles of Calcium Carbonate Synthesized with Food Friendly Polymer Additives2015In: Crystal Growth & Design, ISSN 1528-7483, E-ISSN 1528-7505, Vol. 15, no 8, p. 3609-3616Article in journal (Refereed)
    Abstract [en]

    Porous calcium carbonate particles were synthesized by adding solutions of Ca2+ to solutions of CO32- containing polymeric additives. Under optimized conditions well-defined aggregates of the anhydrous polymorph vaterite formed. A typical sample of these micrometer-sized aggregates had: a pore volume of 0.1 cm(3)/g, a pore width of similar to 10 nm, and a specific surface area of similar to 25-30 m(2)/ g. Only one mixing Order (calcium to carbonate) allowed the formation of vaterite, which was ascribed to the buffering capacity and relatively high pH of the CO32- solution. Rapid addition of the calcium chloride solution and rapid stirring promoted the formation of vaterite, due to the high supersaturation levels achieved. With xanthan gum, porous and micrometer-sized vaterite aggregates could be synthesized over a wide range of synthetic conditions. For the Other food grade polymers, hydroxypropyl methylcellulose (HPMC), methylcellulose (MC), and sodium carboxyl methylcellulose, several intensive and extensive synthetic parameters had to be optimized to obtain pure vaterite and porous aggregates. HPMC and MC allowed well-defined spherical micrometer-sited particles to form. We expect that these spherical and porous particles of vaterite could be relevant to model studies as well as a controlled delivery of particularly large molecules.

  • 277.
    Abed, Sarah
    Stockholm University, Faculty of Humanities, Department of English.
    Teachers’ perceptions of peer review on written assignment in English: A qualitative study of six teachers at two junior high schools in Stockholm2018Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Peer review is aan interestingwell-researched  topic, with much research focusing on the students’' own perceptions of peer review/assessment as well as benefits and challenges with the method. However, little research has been conducted on teachers’ perceptions of students’ peer review of written assignments in English, with a general focus on junior high school level in a Swedish school. Thus, this study was aimed at examining six English teachers’´ perceptions and their usage of peer review of written assignments in English at two junior high schools in Stockholm. A qualitative method was applied, with semi-structured interviews which were analysed using content analysis. The findings revealed that the teachers used different strategies during peer review depending on students’ knowledge level, social competence and the challenges and opportunities that the method offered. Despite a lack of knowledge about the English language and other variables such as different personalities and lack of self-confidence causing difficulties for students to implement peer review as intended, teachers still had positive attitudes towards peer review on written assignments in English. In order to enhance the implementation of peer review, both teachers and students need to become familiar with the practical implementation of the method. Future classroom research within the Swedish education system will help engender favourable conditions that move learning forward.

  • 278.
    Abedi Valugerdi, Natasha
    Stockholm University, Faculty of Law, Department of Law.
    Parallel trade of pharmaceutical drugs within the European Union: a competition law perspective2017Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
  • 279.
    Abedi-Valugerdi, Manuchehr
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
    Mercury and silver induce B cell activation and anti-nucleolar autoantibody production in outbred mouse stocks: are environmental factors more important than the susceptibility genes in connection with autoimmunity?2009In: Clinical and Experimental Immunology, ISSN 0009-9104, E-ISSN 1365-2249, Vol. 155, no 1, p. 117-124Article in journal (Refereed)
    Abstract [en]

    Environmental and predisposing genetic factors are known to play a crucial role in the development of systemic autoimmune diseases. With respect to the role of environmental factors, it is not known how and to what extent they contribute to the initiation and exacerbation of systemic autoimmunity. In the present study, I considered this issue and asked if environmental factors can induce autoimmunity in the absence of specific susceptible genes. The development of genetically controlled mercury- and silver-induced B cell activation and anti-nucleolar autoantibodies (ANolA) production in genetically heterozygous outbred Institute of Cancer Research (ICR), Naval Medical Research Institute (NMRI) and Black Swiss mouse stocks were analysed. Four weeks of treatment with both mercury and silver induced a strong B cell activation characterized by increased numbers of splenic antibody-secreting cells of at least one or more immunoglobulin (Ig) isotype(s) in all treated stocks. The three stocks also exhibited a marked increase in the serum IgE levels in response to mercury, but not silver. More importantly, in response to mercury a large numbers of ICR (88%), NMRI (96%) and Black Swiss (100%) mice produced different levels of IgG1 and IgG2a ANolA (a characteristic which is linked strictly to the H-2 genes). Similarly, but at lower magnitudes, treatment with silver also induced the production of IgG1 and IgG2a ANolA in 60% of ICR, 75% of NMRI and 100% of Black Swiss mice. Thus, the findings of this study suggest that long-term exposure to certain environmental factors can activate the immune system to produce autoimmunity per se, without requiring specific susceptible genes.

  • 280. Abedi-Valugerdi, Manuchehr
    et al.
    Hansson, Monika
    Stockholm University, Faculty of Science, Wenner-Gren Institute for Experimental Biology.
    Möller, Göran
    Genetic control of resistance to mercury-induced immune/autoimmune activation2001In: Scandinavian Journal of Immunology, Vol. 54, no Jul-Aug, p. 190-197Article in journal (Refereed)
  • 281.
    Abejón, Matilde
    Stockholm University, Faculty of Law, Department of Law.
    Särskild granskning enligt aktiebolagslagen: en analys av rättsinstitutets ändamålsenlighet som minoritetsskydd2017Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
  • 282.
    Abel Green, Rebecka
    Stockholm University, Faculty of Social Sciences, Department of Child and Youth Studies.
    Avancerade appars samhandling med yngre barn i en förskolepraktik: En kvalitativ studie om ett- och tvååringars möte med appar utifrån posthumanistiska teorier2016Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Studien utgår ifrån posthumanistiska teorier som ser på mänsklig och icke-mänsklig materia som agentiska aktörer. Studien undersöker vad som uppstår emellan yngre barn och appar i förskolan. Utifrån utvalda videosekvenser där ett- och tvååriga barn samhandlar med avancerade appar i en förskolepraktik analyseras sekvenserna utifrån posthumanistiska begrepp och ANT-analys. Resultatet belyser mycket täta, intensiva och komplexa möten där varje intra-aktion förändrar och transformerar de innefattande aktörerna i nätverk. Fokus ligger på kommunikativa relationer av transdisciplinära tillblivelseprocesser av barns och avancerade appars möten.

  • 283.
    Abel Green, Rebecka
    Stockholm University, Faculty of Social Sciences, Department of Child and Youth Studies.
    Avancerade appars samhandling med yngre barn i en förskolepraktik: En kvalitativ studie om ett- och tvååringars möte med appar utifrån posthumanistiska teorier2016Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Studien utgår ifrån posthumanistiska teorier som ser på mänsklig och icke-mänsklig materia som agentiska aktörer. Studien undersöker vad som uppstår emellan yngre barn och appar i förskolan. Utifrån utvalda videosekvenser där ett- och tvååriga barn samhandlar med avancerade appar i en förskolepraktik analyseras sekvenserna utifrån posthumanistiska begrepp och ANT-analys. Resultatet belyser mycket täta, intensiva och komplexa möten där varje intra-aktion förändrar och transformerar de innefattande aktörerna i nätverk. Fokus ligger på kommunikativa relationer av transdisciplinära tillblivelseprocesser av barns och avancerade appars möten.

  • 284. Abel, Sebastian
    et al.
    Nybom, Inna
    Maenpaa, Kimmo
    Hale, Sarah E.
    Cornelissen, Gerard
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry. Norwegian Geotechnical Institute, Norway; Norwegian University of Life Sciences, Norway.
    Akkanen, Jarkko
    Mixing and capping techniques for activated carbon based sediment remediation Efficiency and adverse effects for Lumbriculus variegatus2017In: Water Research, ISSN 0043-1354, E-ISSN 1879-2448, Vol. 114, p. 104-112Article in journal (Refereed)
    Abstract [en]

    Activated carbon (AC) has been proven to be highly effective for the in-situ remediation of sediments contaminated with a wide range of hydrophobic organic contaminants (HOCs). However, adverse biological effects, especially to benthic organisms, can accompany this promising remediation potential. In this study, we compare both the remediation potential and the biological effects of several AC materials for two application methods: mixing with sediment (MIX) at doses of 0.1 and 1.0% based on sediment dw and thin layer capping (TLC) with 0.6 and 1.2 kg AC/m(2). Significant dose dependent reductions in PCB bioaccumulation in Lumbriculus variegatus of 35-93% in MIX treatments were observed. Contaminant uptake in TLC treatments was reduced by up to 78% and differences between the two applied doses were small. Correspondingly, significant adverse effects were observed for L. variegatus whenever AC was present in the sediment. The lowest application dose of 0.1% AC in the MIX system reduced L variegatus growth, and 1.0% AC led to a net loss of organism biomass. All TLC treatments let to a loss of biomass in the test organism. Furthermore, mortality was observed with 1.2 kg ACim(2) doses of pure AC for the TLC treatment. The addition of clay (Kaolinite) to the TLC treatments prevented mortality, but did not decrease the loss in biomass. While TLC treatments pose a less laborious alternative for AC amendments in the field, the results of this study show that it has lower remediation potential and could be more harmful to the benthic fauna.

  • 285.
    Abel, Ulf
    Stockholm University.
    Carl Milles: form, idé, medaljkonst = Carl Milles : form, idea, medallic art1980Doctoral thesis, monograph (Other academic)
  • 286.
    Abelein, Axel
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
    Modulation of Alzheimer's amyloid β peptide self-assembly: Insights into molecular mechanisms of peptide aggregation associated with Alzheimer's disease2015Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Misfolding of proteins and peptides is closely linked to several neurodegenerative disorders, among them Alzheimer's disease (AD), the most prominent example of brain diseases. The self-assembly of the amyloid β peptide (Aβ) into amyloid fibrils is one histologic hallmark of AD. A detailed knowledge about the underlying mechanism(s) of Aβ aggregation is crucial for advances toward a fundamental understanding of the disease, which may promote the search for and design of efficient therapeutics. The work presented in this thesis deals with modulation of the aggregation process by various compounds, i.e. small organic molecules (e.g. lacmoid and Congo red), surfactants and metal ions. These results provide insight into the molecular mechanism of modulator interactions and interference with Aβ and its aggregation pathways. Applying a combination of kinetic and dynamic studies as well as structural investigations we characterized the molecular interactions between Aβ and aggregation modulators in terms of microscopic rate constants, conformational preferences and thermodynamics. An important conclusion is that these modulators form highly dynamic complexes with Aβ, with life-times on the timescale of milliseconds. Despite the similar exchange dynamics, the effect on peptide aggregation is modulator-specific and fibril formation can be accelerated, retarded or inhibited by their interactions. In summary, Aβ self-assembly is governed by microscopic kinetic and dynamic processes that can be altered by aggregation modulators. Further elucidation of these mechanisms is beneficial for the understanding and therapeutic intervention of amyloid diseases.

  • 287.
    Abelein, Axel
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
    Modulation of amyloid β peptide self-assembly: Aggregation mechanisms associated with Alzheimer's disease2013Licentiate thesis, comprehensive summary (Other academic)
  • 288.
    Abelein, Axel
    et al.
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
    Abrahams, Jan Pieter
    Danielsson, Jens
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
    Gräslund, Astrid
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
    Jarvet, Juri
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics. National Institute of Chemical Physics and Biophysics, Estonia.
    Luo, Jinghui
    Tiiman, Ann
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
    Wärmländer, Sebastian K. T. S.
    The hairpin conformation of the amyloid beta peptide is an important structural motif along the aggregation pathway2014In: Journal of Biological Inorganic Chemistry, ISSN 0949-8257, E-ISSN 1432-1327, Vol. 19, no 4-5, p. 623-634Article, review/survey (Refereed)
    Abstract [en]

    The amyloid beta (A beta) peptides are 39-42 residue-long peptides found in the senile plaques in the brains of Alzheimer's disease (AD) patients. These peptides self-aggregate in aqueous solution, going from soluble and mainly unstructured monomers to insoluble ordered fibrils. The aggregation process(es) are strongly influenced by environmental conditions. Several lines of evidence indicate that the neurotoxic species are the intermediate oligomeric states appearing along the aggregation pathways. This minireview summarizes recent findings, mainly based on solution and solid-state NMR experiments and electron microscopy, which investigate the molecular structures and characteristics of the A beta peptides at different stages along the aggregation pathways. We conclude that a hairpin-like conformation constitutes a common motif for the A beta peptides in most of the described structures. There are certain variations in different hairpin conformations, for example regarding H-bonding partners, which could be one reason for the molecular heterogeneity observed in the aggregated systems. Interacting hairpins are the building blocks of the insoluble fibrils, again with variations in how hairpins are organized in the cross-section of the fibril, perpendicular to the fibril axis. The secondary structure propensities can be seen already in peptide monomers in solution. Unfortunately, detailed structural information about the intermediate oligomeric states is presently not available. In the review, special attention is given to metal ion interactions, particularly the binding constants and ligand structures of A beta complexes with Cu(II) and Zn(II), since these ions affect the aggregation process(es) and are considered to be involved in the molecular mechanisms underlying AD pathology.

  • 289.
    Abelein, Axel
    et al.
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
    Bolognesi, Benedetta
    Dobson, Christopher M.
    Gräslund, Astrid
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
    Lendel, Christofer
    Hydrophobicity and conformational change as mechanistic determinants for nonspecific modulators of amyloid β self-assembly2012In: Biochemistry, ISSN 0006-2960, E-ISSN 1520-4995, Vol. 51, no 1, p. 126-137Article in journal (Refereed)
    Abstract [en]

    The link between many neurodegenerative disorders, including Alzheimer's and Parkinson's diseases, and the aberrant folding and aggregation of proteins has prompted a comprehensive search for small organic molecules that have the potential to inhibit such processes. Although many compounds have been reported to affect the formation of amyloid fibrils and/or other types of protein aggregates, the mechanisms by which they act are not well understood. A large number of compounds appear to act in a nonspecific way affecting several different amyloidogenic proteins. We describe here a detailed study of the mechanism of action of one representative compound, lacmoid, in the context of the inhibition of the aggregation of the amyloid β-peptide (Aβ) associated with Alzheimer's disease. We show that lacmoid binds Aβ(1-40) in a surfactant-like manner and counteracts the formation of all types of Aβ(1-40) and Aβ(1-42) aggregates. On the basis of these and previous findings, we are able to rationalize the molecular mechanisms of action of nonspecific modulators of protein self-assembly in terms of hydrophobic attraction and the conformational preferences of the polypeptide.

  • 290.
    Abelein, Axel
    et al.
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
    Gräslund, Astrid
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
    Danielsson, Jens
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
    The zinc ion – a minimal chaperone mimicking agent forretardation of amyloid β peptide fibril formationManuscript (preprint) (Other academic)
  • 291.
    Abelein, Axel
    et al.
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
    Gräslund, Astrid
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
    Danielsson, Jens
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
    Zinc as chaperone-mimicking agent for retardation of amyloid beta peptide fibril formation2015In: Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424, E-ISSN 1091-6490, Vol. 112, no 17, p. 5407-5412Article in journal (Refereed)
    Abstract [en]

    Metal ions have emerged to play a key role in the aggregation process of amyloid beta (A beta) peptide that is closely related to the pathogenesis of Alzheimer's disease. A detailed understanding of the underlying mechanistic process of peptide-metal interactions, however, has been challenging to obtain. By applying a combination of NMR relaxation dispersion and fluorescence kinetics methods we have investigated quantitatively the thermodynamic A beta-Zn2+ binding features as well as how Zn2+ modulates the nucleation mechanism of the aggregation process. Our results show that, under near-physiological conditions, substoichiometric amounts of Zn2+ effectively retard the generation of amyloid fibrils. A global kinetic profile analysis reveals that in the absence of zinc A beta(40) aggregation is driven by a monomer-dependent secondary nucleation process in addition to fibril-end elongation. In the presence of Zn2+, the elongation rate is reduced, resulting in reduction of the aggregation rate, but not a complete inhibition of amyloid formation. We show that Zn2+ transiently binds to residues in the N terminus of the monomeric peptide. A thermodynamic analysis supports a model where the N terminus is folded around the Zn2+ ion, forming a marginally stable, short-lived folded A beta(40) species. This conformation is highly dynamic and only a few percent of the peptide molecules adopt this structure at any given time point. Our findings suggest that the folded A beta(40)-Zn2+ complex modulates the fibril ends, where elongation takes place, which efficiently retards fibril formation. In this conceptual framework we propose that zinc adopts the role of a minimal antiaggregation chaperone for A beta(40).

  • 292.
    Abelein, Axel
    et al.
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
    Jarvet, Jüri
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics. The National Institute of Chemical Physics and Biophysics, Estonia.
    Barth, Andreas
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
    Gräslund, Astrid
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
    Danielsson, Jens
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
    Ionic Strength Modulation of the Free Energy Landscape of A beta(40) Peptide Fibril Formation2016In: Journal of the American Chemical Society, ISSN 0002-7863, E-ISSN 1520-5126, Vol. 138, no 21, p. 6893-6902Article in journal (Refereed)
    Abstract [en]

    Protein misfolding and formation of cross-beta structured amyloid fibrils are linked to, many neurodegenerative disorders. Although recently developed,quantitative approaches have started to reveal the molecular nature of self-assembly and fibril formation of proteins and peptides, it is yet unclear how these self-organization events are precisely modulated by microenvironmental factors, which are known to strongly affect the macroscopic aggregation properties. Here, we characterize the explicit effect of ionic strength on the microscopic aggregation rates of amyloid beta peptide (A beta 40) self-association, implicated in Alzheimer's disease. We found that physiological ionic strength accelerates A beta 40 aggregation kinetics by promoting surface-catalyzed secondary nucleation reactions. This promoted catalytic effect can be assigned to shielding of electrostatic repulsion between Monomers on the fibril surface or between the fibril surface itself and monomeric peptides. Furthermore, we observe the formation of two different beta-structured states with =similar but distinct spectroscopic features, which can be assigned to an off-pathway immature state (F-beta*) and a mature stable State (F-beta), where salt favors formation of the F-beta fibril morphology. Addition of salt to preformed F-beta* accelerates transition to F-beta, underlining the dynamic nature of A beta 40 fibrils in solution. On the basis of,these results we suggest a model where salt decreases the free-energy barrier for A beta 40 folding to the F-beta state, favoring the buildup of the mature fibril morphology while omitting competing, energetically less favorable structural states.

  • 293.
    Abelein, Axel
    et al.
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
    Kaspersen, Jørn Døvling
    Nielsen, Søren Bang
    Jensen, Grethe Vestergaard
    Christiansen, Gunna
    Pedersen, Jan Skov
    Danielsson, Jens
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
    Otzen, Daniel E.
    Gräslund, Astrid
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
    Formation of dynamic soluble surfactant-induced amyloid β peptide aggregation intermediates2013In: Journal of Biological Chemistry, ISSN 0021-9258, E-ISSN 1083-351X, Vol. 288, no 32, p. 23518-23528Article in journal (Refereed)
    Abstract [en]

    Intermediate amyloidogenic states along the amyloid β peptide (Aβ) aggregation pathway have been shown to be linked to neurotoxicity. To shed more light on the different structures that may arise during Aβ aggregation, we here investigate surfactant-induced Aβ aggregation. This process leads to co-aggregates featuring a β-structure motif that is characteristic for mature amyloid-like structures. Surfactants induce secondary structure in Aβ in a concentration-dependent manner, from predominantly random coil at low surfactant concentration, via β-structure to the fully formed α-helical state at high surfactant concentration. The β-rich state is the most aggregation-prone as monitored by thioflavin T fluorescence. Small angle x-ray scattering reveals initial globular structures of surfactant-Aβ co-aggregated oligomers and formation of elongated fibrils during a slow aggregation process. Alongside this slow (minutes to hours time scale) fibrillation process, much faster dynamic exchange (k(ex) ∼1100 s(-1)) takes place between free and co-aggregate-bound peptide. The two hydrophobic segments of the peptide are directly involved in the chemical exchange and interact with the hydrophobic part of the co-aggregates. Our findings suggest a model for surfactant-induced aggregation where free peptide and surfactant initially co-aggregate to dynamic globular oligomers and eventually form elongated fibrils. When interacting with β-structure promoting substances, such as surfactants, Aβ is kinetically driven toward an aggregation-prone state.

  • 294.
    Abelein, Axel
    et al.
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
    Lang, Lisa
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
    Lendel, Christofer
    Gräslund, Astrid
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
    Danielsson, Jens
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
    Corrigendum to “Transient small molecule interactions kinetically modulate amyloid β peptide self-assembly” [FEBS Lett. 586 (2012) 3991–3995]2013In: FEBS Letters, ISSN 0014-5793, E-ISSN 1873-3468, Vol. 587, no 9, p. 1452-1452Article in journal (Other academic)
  • 295.
    Abelein, Axel
    et al.
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
    Lang, Lisa
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
    Lendel, Christofer
    Gräslund, Astrid
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
    Danielsson, Jens
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
    Transient small molecule interactions kinetically modulate amyloid beta peptide self-assembly2012In: FEBS Letters, ISSN 0014-5793, E-ISSN 1873-3468, Vol. 586, no 22, p. 3991-3995Article in journal (Refereed)
    Abstract [en]

    Small organic molecules, like Congo red and lacmoid, have been shown to modulate the self-assembly of the amyloid beta peptide (A beta). Here, we show that A beta forms NMR invisible non-toxic co-aggregates together with lacmoid as well as Congo red. We find that the interaction involves two distinct kinetic processes and at every given time point only a small fraction of A beta is in the co-aggregate. These weak transient interactions kinetically redirect the aggregation prone A beta from self-assembling into amyloid fibrils. These findings suggest that even such weak binders might be effective as therapeutics against pathogenic protein aggregation.

  • 296.
    Abelin, Matthias
    Stockholm University, Faculty of Social Sciences, School of Business.
    Processorientering och lärande organisation på Huddinge Universitetssjukhus AB - En beskrivning av ett pågående förändringsarbete inom sjukvården2000Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    En beskrivning och kategorisering av ett arbete med att processorientera och skapa en lärande organisation på Huddinge Universitetssjukhus AB, som pågått sedan 1996. En observation är att metodik förknippad med pragmatism och lärande organisation vid organisationsförändring kan minska risken pga större flexibilitet och lyhördhet för organisationskulturen och det specifika för en viss verksamhet.

  • 297. Abelin, Åsa
    et al.
    Zetterholm, Elisabeth
    Stockholm University, Faculty of Humanities, Department of Language Education.
    Spanish accented Swedish – when the neighbor becomes a fir-tree2019In: Comunicación Social: Lingüística, Medios Masivos, Arte, Etnología, Folclor y otras ciencias afines / [ed] María Rosa Álvarez Silva, Alex Muñoz Alvarado, Leonel Ruiz Miyares, Santiago de Cuba: Ediciones Centro de Lingüística Aplicada , 2019Conference paper (Refereed)
  • 298. Abellán, F. J.
    et al.
    Indebetouw, R.
    Marcaide, J. M.
    Gabler, M.
    Fransson, Claes
    Stockholm University, Faculty of Science, Department of Astronomy. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Spyromilio, J.
    Burrows, D. N.
    Chevalier, R.
    Cigan, P.
    Gaensler, B. M.
    Gomez, H. L.
    Janka, H. -Th.
    Kirshner, R.
    Larsson, J.
    Lundqvist, Peter
    Stockholm University, Faculty of Science, Department of Astronomy. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Matsuura, M.
    McCray, R.
    Ng, C. -Y.
    Park, S.
    Roche, P.
    Staveley-Smith, L.
    van Loon, J. Th.
    Wheeler, J. C.
    Woosley, S. E.
    Very Deep inside the SN 1987A Core Ejecta: Molecular Structures Seen in 3D2017In: Astrophysical Journal Letters, ISSN 2041-8205, E-ISSN 2041-8213, Vol. 842, no 2, article id L24Article in journal (Refereed)
    Abstract [en]

    Most massive stars end their lives in core-collapse supernova explosions and enrich the interstellar medium with explosively nucleosynthesized elements. Following core collapse, the explosion is subject to instabilities as the shock propagates outward through the progenitor star. Observations of the composition and structure of the innermost regions of a core-collapse supernova provide a direct probe of the instabilities and nucleosynthetic products. SN 1987A in the Large Magellanic Cloud is one of very few supernovae for which the inner ejecta can be spatially resolved but are not yet strongly affected by interaction with the surroundings. Our observations of SN 1987A with the Atacama Large Millimeter/submillimeter Array are of the highest resolution to date and reveal the detailed morphology of cold molecular gas in the innermost regions of the remnant. The 3D distributions of carbon and silicon monoxide (CO and SiO) emission differ, but both have a central deficit, or torus-like distribution, possibly a result of radioactive heating during the first weeks (nickel heating). The size scales of the clumpy distribution are compared quantitatively to models, demonstrating how progenitor and explosion physics can be constrained.

  • 299. Abel-Ollo, K.
    et al.
    Rahu, M.
    Rajaleid, K.
    Stockholm University, Faculty of Social Sciences, Centre for Health Equity Studies (CHESS).
    Talu, A.
    Ruutel, K.
    Platt, L.
    Bobrova, N.
    Rhodes, T.
    Uuskula, A.
    Knowledge of HIV serostatus and risk behaviour among injecting drug users in Estonia2009In: AIDS Care, ISSN 0954-0121, E-ISSN 1360-0451, Vol. 21, no 7, p. 851-857Article in journal (Refereed)
    Abstract [en]

    We used the findings from two, cross-sectional studies of HIV serostatus and risk behaviours to assess the effects of knowledge of HIV serostatus and risk behaviours (relating to sex and injection drug use) among injecting drug users (IDUs). Respondent-driven sampling was used simultaneously at two sites in Estonia (the capital Tallinn, and the second-largest city of Ida-Virumaa County, Kohtla-Järve). The research tool was an interviewer-administered survey. Biological samples were collected for HIV testing. Participants were categorised into three groups based on HIV testing results and self-report on HIV serostatus: HIV-negative (n=133); HIV-positive unaware of their serostatus (n=75); and HIV-positive aware of their serostatus (n=168). In total, 65% of the participants tested positive for HIV. Of those 69% were aware of their positive serostatus. HIV-positive IDUs aware of their serostatus exhibited more risk behaviours than their HIV-positive counterparts unaware of their serostatus or HIV-negative IDUs. Effective prevention of HIV among IDUs should therefore, include programmes to reduce high-risk sexual and drug use behaviours at the public health scale and enhanced prevention efforts focusing on HIV-infected individuals.

  • 300. Aben, Ralf C. H.
    et al.
    Barros, Nathan
    van Donk, Ellen
    Frenken, Thijs
    Hilt, Sabine
    Kazanjian, Garabet
    Lamers, Leon P. M.
    Peeters, Edwin T. H. M.
    Roelofs, Jan G. M.
    de Senerpont Domis, Lisette N.
    Stephan, Susanne
    Velthuis, Mandy
    Van de Waal, Dedmer B.
    Wik, Martin
    Stockholm University, Faculty of Science, Department of Geological Sciences.
    Thornton, Brett F.
    Stockholm University, Faculty of Science, Department of Geological Sciences.
    Wilkinson, Jeremy
    DelSontro, Tonya
    Kosten, Sarian
    Cross continental increase in methane ebullition under climate change2017In: Nature Communications, ISSN 2041-1723, E-ISSN 2041-1723, Vol. 8, article id 1682Article in journal (Refereed)
    Abstract [en]

    Methane (CH4) strongly contributes to observed global warming. As natural CH4 emissions mainly originate from wet ecosystems, it is important to unravel how climate change may affect these emissions. This is especially true for ebullition (bubble flux from sediments), a pathway that has long been underestimated but generally dominates emissions. Here we show a remarkably strong relationship between CH4 ebullition and temperature across a wide range of freshwater ecosystems on different continents using multi-seasonal CH4 ebullition data from the literature. As these temperature-ebullition relationships may have been affected by seasonal variation in organic matter availability, we also conducted a controlled year-round mesocosm experiment. Here 4 degrees C warming led to 51% higher total annual CH4 ebullition, while diffusion was not affected. Our combined findings suggest that global warming will strongly enhance freshwater CH4 emissions through a disproportional increase in ebullition (6-20% per 1 degrees C increase), contributing to global warming.

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