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  • 2101. Ahmadi, M.
    et al.
    Alves, B. X. R.
    Baker, C. J.
    Bertsche, W.
    Butler, E.
    Capra, A.
    Carruth, C.
    Cesar, C. L.
    Charlton, M.
    Cohen, S.
    Collister, R.
    Eriksson, S.
    Evans, A.
    Evetts, N.
    Fajans, J.
    Friesen, T.
    Fujiwara, M. C.
    Gill, D. R.
    Gutierrez, A.
    Hangst, J. S.
    Hardy, W. N.
    Hayden, M. E.
    Isaac, C. A.
    Ishida, A.
    Johnson, M. A.
    Jones, S. A.
    Jonsell, Svante
    Stockholm University, Faculty of Science, Department of Physics.
    Kurchaninov, L.
    Madsen, N.
    Mathers, M.
    Maxwell, D.
    McKenna, J. T. K.
    Menary, S.
    Michan, J. M.
    Momose, T.
    Munich, J. J.
    Nolan, P.
    Olchanski, K.
    Olin, A.
    Pusa, P.
    Rasmussen, C. Ø.
    Robicheaux, F.
    Sacramento, R. L.
    Sameed, M.
    Sarid, E.
    Silveira, D. M.
    Stracka, S.
    Stutter, G.
    So, C.
    Tharp, T. D.
    Thompson, J. E.
    Thompson, R. I.
    van der Werf, D. P.
    Wurtele, J. S.
    Antihydrogen accumulation for fundamental symmetry tests2017In: Nature Communications, ISSN 2041-1723, E-ISSN 2041-1723, Vol. 8, article id 681Article in journal (Refereed)
    Abstract [en]

    Antihydrogen, a positron bound to an antiproton, is the simplest anti-atom. Its structure and properties are expected to mirror those of the hydrogen atom. Prospects for precision comparisons of the two, as tests of fundamental symmetries, are driving a vibrant programme of research. In this regard, a limiting factor in most experiments is the availability of large numbers of cold ground state antihydrogen atoms. Here, we describe how an improved synthesis process results in a maximum rate of 10.5 +/- 0.6 atoms trapped and detected per cycle, corresponding to more than an order of magnitude improvement over previous work. Additionally, we demonstrate how detailed control of electron, positron and antiproton plasmas enables repeated formation and trapping of antihydrogen atoms, with the simultaneous retention of atoms produced in previous cycles. We report a record of 54 detected annihilation events from a single release of the trapped anti-atoms accumulated from five consecutive cycles.

  • 2102. Ahmadi, M.
    et al.
    Alves, B. X. R.
    Baker, C. J.
    Bertsche, W.
    Capra, A.
    Carruth, C.
    Cesar, C. L.
    Charlton, M.
    Cohen, S.
    Collister, R.
    Eriksson, S.
    Evans, A.
    Evetts, N.
    Fajans, J.
    Friesen, T.
    Fujiwara, M. C.
    Gill, D. R.
    Hangst, J. S.
    Hardy, W. N.
    Hayden, M. E.
    Hunter, E. D.
    Isaac, C. A.
    Johnson, M. A.
    Jones, J. M.
    Jones, S. A.
    Jonsell, Svante
    Stockholm University, Faculty of Science, Department of Physics.
    Khramov, A.
    Knapp, P.
    Kurchaninov, L.
    Madsen, N.
    Maxwell, D.
    McKenna, J. T. K.
    Menary, S.
    Michan, J. M.
    Momose, T.
    Munich, J. J.
    Olchanski, K.
    Olin, A.
    Pusa, P.
    Rasmussen, C. O.
    Robicheaux, F.
    Sacramento, R. L.
    Sameed, M.
    Sarid, E.
    Silveira, D. M.
    Starko, D. M.
    Stutter, G.
    So, C.
    Tharp, T. D.
    Thompson, R. I.
    van der Werf, D. P.
    Wurtele, J. S.
    Observation of the 1S-2P Lyman-alpha transition in antihydrogen2018In: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 561, no 7722, p. 211-217Article in journal (Refereed)
    Abstract [en]

    In 1906, Theodore Lyman discovered his eponymous series of transitions in the extreme-ultraviolet region of the atomic hydrogen spectrum(1,2). The patterns in the hydrogen spectrum helped to establish the emerging theory of quantum mechanics, which we now know governs the world at the atomic scale. Since then, studies involving the Lyman-alpha line-the 1S-2P transition at a wavelength of 121.6 nanometres-have played an important part in physics and astronomy, as one of the most fundamental atomic transitions in the Universe. For example, this transition has long been used by astronomers studying the intergalactic medium and testing cosmological models via the so-called 'Lyman-alpha forest('3) of absorption lines at different redshifts. Here we report the observation of the Lyman-alpha transition in the antihydrogen atom, the antimatter counterpart of hydrogen. Using narrow-line-width, nanosecond-pulsed laser radiation, the 1S-2P transition was excited in magnetically trapped antihydrogen. The transition frequency at a field of 1.033 tesla was determined to be 2,466,051.7 +/- 0.12 gigahertz (1 sigma uncertainty) and agrees with the prediction for hydrogen to a precision of 5 x 10(-8). Comparisons of the properties of antihydrogen with those of its well-studied matter equivalent allow precision tests of fundamental symmetries between matter ;and antimatter. Alongside the ground-state hyperfine(4,5) and 1S-2S transitions(6,7) recently observed in antihydrogen, the Lyman-alpha transition will permit laser cooling of antihydrogen(8,9), thus providing a cold and dense sample of anti-atoms for precision spectroscopy and gravity measurements(10). In addition to the observation of this fundamental transition, this work represents both a decisive technological step towards laser cooling of antihydrogen, and the extension of antimatter spectroscopy to quantum states possessing orbital angular momentum.

  • 2103. Ahmadi, M.
    et al.
    Alves, B. X. R.
    Baker, C. J.
    Bertsche, W.
    Capra, A.
    Carruth, C.
    Cesar, C. L.
    Charlton, M.
    Cohen, S.
    Collister, R.
    Eriksson, S.
    Evans, A.
    Evetts, N.
    Fajans, J.
    Friesen, T.
    Fujiwara, M. C.
    Gill, D. R.
    Hangst, J. S.
    Hardy, W. N.
    Hayden, M. E.
    Isaac, C. A.
    Johnson, M. A.
    Jones, J. M.
    Jones, S. A.
    Jonsell, Svante
    Stockholm University, Faculty of Science, Department of Physics.
    Khramov, A.
    Knapp, P.
    Kurchaninov, L.
    Madsen, N.
    Maxwell, D.
    McKenna, J. T. K.
    Menary, S.
    Momose, T.
    Munich, J. J.
    Olchanski, K.
    Olin, A.
    Pusa, P.
    Rasmussen, C. O.
    Robicheaux, F.
    Sacramento, R. L.
    Sameed, M.
    Sarid, E.
    Silveira, D. M.
    Stutter, G.
    So, C.
    Tharp, T. D.
    Thompson, R. I.
    van der Werf, D. P.
    Wurtele, J. S.
    Characterization of the 1S-2S transition in antihydrogen2018In: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 557, no 7703, p. 71-+Article in journal (Refereed)
    Abstract [en]

    In 1928, Dirac published an equation(1) that combined quantum mechanics and special relativity. Negative-energy solutions to this equation, rather than being unphysical as initially thought, represented a class of hitherto unobserved and unimagined particles-antimatter. The existence of particles of antimatter was confirmed with the discovery of the positron(2) (or anti-electron) by Anderson in 1932, but it is still unknown why matter, rather than antimatter, survived after the Big Bang. As a result, experimental studies of antimatter(3-7), including tests of fundamental symmetries such as charge-parity and charge-parity-time, and searches for evidence of primordial antimatter, such as antihelium nuclei, have high priority in contemporary physics research. The fundamental role of the hydrogen atom in the evolution of the Universe and in the historical development of our understanding of quantum physics makes its antimatter counterpart-the antihydrogen atom-of particular interest. Current standard-model physics requires that hydrogen and antihydrogen have the same energy levels and spectral lines. The laser-driven 1S-2S transition was recently observed(8) in antihydrogen. Here we characterize one of the hyperfine components of this transition using magnetically trapped atoms of antihydrogen and compare it to model calculations for hydrogen in our apparatus. We find that the shape of the spectral line agrees very well with that expected for hydrogen and that the resonance frequency agrees with that in hydrogen to about 5 kilohertz out of 2.5 x 10(15) hertz. This is consistent with charge-parity-time invariance at a relative precision of 2 x 10(-12)-two orders of magnitude more precise than the previous determination(8)-corresponding to an absolute energy sensitivity of 2 x 10(-20) GeV.

  • 2104. Ahmadi, M.
    et al.
    Alves, B. X. R.
    Baker, C. J.
    Bertsche, W.
    Capra, A.
    Carruth, C.
    Cesar, C. L.
    Charlton, M.
    Cohen, S.
    Collister, R.
    Eriksson, S.
    Evans, A.
    Evetts, N.
    Fajans, J.
    Friesen, T.
    Fujiwara, M. C.
    Gill, D. R.
    Hangst, J. S.
    Hardy, W. N.
    Hayden, M. E.
    Isaac, C. A.
    Johnson, M. A.
    Jones, S. A.
    Jonsell, Svante
    Stockholm University, Faculty of Science, Department of Physics.
    Kurchaninov, L.
    Madsen, N.
    Mathers, M.
    Maxwell, D.
    McKenna, J. T. K.
    Menary, S.
    Momose, T.
    Munich, J. J.
    Olchanski, K.
    Olin, A.
    Pusa, P.
    Rasmussen, C. O.
    Robicheaux, F.
    Sacramento, R. L.
    Sameed, M.
    Sarid, E.
    Silveira, D. M.
    So, C.
    Stutter, G.
    Tharp, T. D.
    Thompson, J. E.
    Thompson, R. I.
    van der Werf, D. P.
    Wurtele, J. S.
    Enhanced Control and Reproducibility of Non-Neutral Plasmas2018In: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 120, no 2, article id 025001Article in journal (Refereed)
    Abstract [en]

    The simultaneous control of the density and particle number of non-neutral plasmas confined in Penning-Malmberg traps is demonstrated. Control is achieved by setting the plasma's density by applying a rotating electric field while simultaneously fixing its axial potential via evaporative cooling. This novel method is particularly useful for stabilizing positron plasmas, as the procedures used to collect positrons from radioactive sources typically yield plasmas with variable densities and particle numbers; it also simplifies optimization studies that require plasma parameter scans. The reproducibility achieved by applying this technique to the positron and electron plasmas used by the ALPHA antihydrogen experiment at CERN, combined with other developments, contributed to a 10-fold increase in the antiatom trapping rate.

  • 2105. Ahmadi, M.
    et al.
    Baquero-Ruiz, M.
    Bertsche, W.
    Butler, E.
    Capra, A.
    Carruth, C.
    Cesar, C. L.
    Charlton, M.
    Charman, A. E.
    Eriksson, S.
    Evans, L. T.
    Evetts, N.
    Fajans, J.
    Friesen, T.
    Fujiwara, M. C.
    Gill, D. R.
    Gutierrez, A.
    Hangst, J. S.
    Hardy, W. N.
    Hayden, M. E.
    Isaac, C. A.
    Ishida, A.
    Jones, S. A.
    Jonsell, Svante
    Stockholm University, Faculty of Science, Department of Physics.
    Kurchaninov, L.
    Madsen, N.
    Maxwell, D.
    McKenna, J. T. K.
    Menary, S.
    Michan, J. M.
    Momose, T.
    Munich, J. J.
    Nolan, P.
    Olchanski, K.
    Olin, A.
    Povilus, A.
    Pusa, P.
    Rasmussen, C. O.
    Robicheaux, F.
    Sacramento, R. L.
    Sameed, M.
    Sarid, E.
    Silveira, D. M.
    So, C.
    Tharp, T. D.
    Thompson, R. I.
    van der Werf, D. P.
    Wurtele, J. S.
    Zhmoginov, A. I.
    An improved limit on the charge of antihydrogen from stochastic acceleration2016In: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 529, no 7586, p. 373-+Article in journal (Refereed)
    Abstract [en]

    Antimatter continues to intrigue physicists because of its apparent absence in the observable Universe. Current theory requires that matter and antimatter appeared in equal quantities after the Big Bang, but the Standard Model of particle physics offers no quantitative explanation for the apparent disappearance of half the Universe. It has recently become possible to study trapped atoms(1-4) of antihydrogen to search for possible, as yet unobserved, differences in the physical behaviour of matter and antimatter. Here we consider the charge neutrality of the antihydrogen atom. By applying stochastic acceleration to trapped antihydrogen atoms, we determine an experimental bound on the antihydrogen charge, Qe, of vertical bar Q vertical bar < 0.71 parts per billion (one standard deviation), in which e is the elementary charge. This bound is a factor of 20 less than that determined from the best previous measurement(5) of the antihydrogen charge. The electrical charge of atoms and molecules of normal matter is known(6) to be no greater than about 10(-21)e for a diverse range of species including H-2, He and SF6. Charge-parity-time symmetry and quantum anomaly cancellation(7) demand that the charge of antihydrogen be similarly small. Thus, our measurement constitutes an improved limit and a test of fundamental aspects of the Standard Model. If we assume charge superposition and use the best measured value of the antiproton charge(8), then we can place a new limit on the positron charge anomaly (the relative difference between the positron and elementary charge) of about one part per billion (one standard deviation), a 25-fold reduction compared to the current best measurement(8),(9).

  • 2106.
    Ahmadi, Mazaher
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry. Bu-Ali Sina University, Iran.
    Elmongy, Hatem
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Madrakian, Tayyebeh
    Abdel-Rehim, Mohamed
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Nanomaterials as sorbents for sample preparation in bioanalysis: A review2017In: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 958, p. 1-21Article, review/survey (Refereed)
    Abstract [en]

    In recent years, application of nanomaterials as sorbent has gained the attention of researchers in bioanalysis. Different nanomaterials have been utilized as the sorbent in extraction techniques such as solid phase extraction, dispersive solid phase extraction, magnetic solid phase extraction, microextraction by packed sorbent, solid phase microextraction, dispersive pt-solid phase extraction, and stir bar sorptive extraction. In the present review, different nanomaterials which have recently been utilized as sorbent for bioanalysis are classified into six main groups, namely metallic, metallic and mixed oxide, magnetic, carbonaceous, silicon, and polymer-based nanomaterials. Application of these nanomaterials in different extraction techniques for bioanalysis has been reviewed. This study shows that magnetic nanomaterials have gained significant attention owing to their magnetic separation ability. In addition, the present review shows that there is a lack in the application of nanomaterials for on-line analysis procedures, most probably due to some intrinsic properties of nanomaterials such as spontaneous agglomeration.

  • 2107. Ahmadi-Afzadi, Masoud
    et al.
    Orsel, Mathilde
    Pelletier, Sandra
    Bruneau, Maryline
    Proux-Wéra, Estelle
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics. Stockholm University, Science for Life Laboratory (SciLifeLab). Swedish University of Agricultural Sciences, Sweden.
    Nybom, Hilde
    Renou, Jean-Pierre
    Genome-wide expression analysis suggests a role for jasmonates in the resistance to blue mold in apple2018In: Plant growth regulation (Print), ISSN 0167-6903, E-ISSN 1573-5087, Vol. 85, no 3, p. 375-387Article in journal (Refereed)
    Abstract [en]

    Blue mold, caused by the necrotrophic fungal pathogen Penicillium expansum, causes serious postharvest losses in apple, and threatens human health through production of the potent mycotoxin patulin. Recent studies indicate a quantitative control of resistance against this disease in apple cultivars. A whole genome apple microarray covering 60k transcripts was used to identify gene(s) that appear to be differentially regulated between resistant and susceptible cultivars in P. expansum-infected fruits. A number of potential candidates was encountered among defense- and oxidative stress-related genes, cell wall modification and lignification genes, and genes related to localization and transport. Induction of one cell wall-related gene and three genes involved in the 'down-stream' flavonoid biosynthesis pathway, demonstrates the fundamental role of the cell wall as an important barrier, and suggests that fruit flavonoids are involved in the resistance to blue mold. Moreover, exogenous application of the plant hormone methyl jasmonate (MeJA) reduced the symptoms resulting from inoculating apples with P. expansum. This is the first report linking MeJA and activation of cell wall and flavonoid pathway genes to resistance against blue mold in a study comparing different cultivars of domesticated apple. Our results provide an initial categorization of genes that are potentially involved in the resistance mechanism, and should be useful for developing tools for gene marker-assisted breeding of apple cultivars with an improved resistance to blue mold.

  • 2108. Ahmed, Adamu
    et al.
    Adama, Onyanta
    Stockholm University, Faculty of Social Sciences, Department of Human Geography.
    Iliyasu, Idris
    Prospects and Retrospect: Insights from Children's participation in Informal Sector Solid Waste Management in Kaduna, Nigeria2017In: Dealing with waste: Resource Recovery and Entrepreneurship in Informal Sector Solid Waste Management in African Cities / [ed] Onyanta Adama, Tadischi Chidi Nzeadibe, Africa World Press, 2017, p. 137-150Chapter in book (Other academic)
  • 2109.
    Ahmed, Engy
    Stockholm University, Faculty of Science, Department of Geological Sciences.
    Microbe-mineral interactions in soil: Investigation of biogenic chelators, microenvironments and weathering processes2015Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The interplay between geology and biology has shaped the Earth during billions of years. Microbe-mineral interactions are prime examples of this interplay and underscore the importance of microorganisms in making Earth a suitable environment for all forms of life. The present thesis takes an interdisciplinary approach to obtain an integrated understanding of microbe-mineral interactions. More specifically it addresses how the composition and distribution of biogenic weathering agents (siderophores) differ with regard to soil horizon and mineral type in situ, what siderophore type soil microorganisms produces under laboratory conditions, what role microbial surface attachment plays in mineral weathering reactions and what central roles and applications siderophores have in the environment.

    Podzol, the third most abundant soil in Europe, and most abundant in Scandinavia, was chosen for a field experiment, where three minerals (apatite, biotite and oligoclase) were inserted in the organic, eluvial and upper illuvial soil horizons. The study started with an investigation of the siderophore composition in the bulk soil profile and on the mineral surfaces (paper I), which was followed by a study of the siderophore producing capabilities of microorganisms isolated from the soil profile under laboratory conditions (paper II). Subsequently, a study was done on the impact of microbial surface attachment on biotite dissolution (paper III). Finally, the roles of siderophores in nature and their potential applications were reviewed (paper IV).

    The major findings were that the concentration of hydroxamate siderophores in the soil attached to the mineral surfaces was greater than those in the surrounding bulk soil, indicating that the minerals stimulate the microbial communities attached to their surfaces to produce more siderophores than the microorganisms in the bulk soil. Each mineral had a unique assemblage of hydroxamate siderophores, that makes the mineral type one of the main factors affecting siderophore composition in the natural environment. Siderophore production varied between the microbial species originating from different soil horizons, suggesting that the metabolic properties of microbes in deep soil horizons function differently from those at upper soil horizons. Microbial surface attachment enhanced the biotite dissolution, showing that attached microbes has a greater influence on weathering reactions in soil than planktonic populations. In conclusion, our findings reflected that the complicated relationship between microorganisms and mineral surfaces reinforces the central theme of biogeochemistry that the mineral controls the biological activity in the natural environments. However, the importance of these relationships to the biogeochemical systems requires further investigation.

  • 2110.
    Ahmed, Engy
    Stockholm University, Faculty of Science, Department of Geological Sciences.
    The interaction between microbes, siderophores and minerals in podzol soil2013Licentiate thesis, comprehensive summary (Other academic)
  • 2111.
    Ahmed, Engy
    et al.
    Stockholm University, Faculty of Science, Department of Geological Sciences. Stockholm University, Science for Life Laboratory (SciLifeLab).
    Abdulla, Hesham M.
    Mohamed, Amy H.
    El-Bassuony, Ahmed D.
    Remediation and recycling of chromium from tannery wastewater using combined chemical-biological treatment system2016In: Process Safety and Environmental Protection, ISSN 0957-5820, E-ISSN 1744-3598, Vol. 104, p. 1-10Article in journal (Refereed)
    Abstract [en]

    Tannery wastewater containing chromium (Cr) is one of the most serious problems in leather industry. In order to develop an effective and eco-friendly treatment technology, a combined chemical-biological treatment system was performed for Cr remediation and recycling. The aim of the present study is to design a laboratory scale system using chemical precipitation of Cr(III) combined with biological removal of Cr(VI) from tannery wastewater, and to investigate the possibility of recycling the recovered Cr(III) in the tanning industry. Chemical precipitation of Cr(III) was carried out using lime and cement dust. The actinomycete strain Kitasatosporia sp. was used in microcosm studies for Cr(VI) bioremoval. Moreover, parameters such as type of porous medium, inoculum size, flow rate and culture conditions were investigated. The precipitated Cr(III) that was recovered from the chemical precipitation stage was recycled in the leather tanning industry. Our findings indicate that the maximum Cr(III) precipitation (98%) was achieved using 2 g/100 mL of lime and 2 h of settling rate. On the other hand, microcosm columns using sand that was inoculated with induced culture (OD600 = 2.43) and flow rate (2 mL/min) gave the maximum recovery (99%) of Cr(VI). The experimental Cr(III) was successfully recycled in the tanning process and the experimental leathers showed comparable properties as same as the leathers tanned with commercial Cr(III). Thus, we concluded that using combined chemical-biological treatment system for Cr remediation from tanning wastewater together with recycling process for the recovered Cr(III) is a promising strategy for economic and environmental friendly tanning industry.

  • 2112.
    Ahmed, Engy
    et al.
    Stockholm University, Faculty of Science, Department of Geological Sciences.
    Holmström, Sara
    Stockholm University, Faculty of Science, Department of Geological Sciences.
    Soil Microorganisms and Mineral Weathering: Mechanics of Biotite Dissolution2012Conference paper (Other academic)
    Abstract [en]

    Soil microorganisms play an important role in the environment by contributing to leach and release of essential elements from soil minerals that are required not only for their own nutrition but also for plants growth. This study aims to compare between the mechanisms of different fungal and bacterial species isolated from podzol soil in biotite dissolution. Microplate devices with 6 wells were used for the biological weathering experiments. All of the sterilized microplate wells were filled with 4g/l of biotite followed by 12 ml of an iron free diluted mineral liquid medium. In these conditions, biotite particles are the only source of the essential elements for the microorganisms. To characterize the mechanisms of biotite dissolution, we monitored siderophores production, microbial biomass, pH, exchangeable cations concentration and SEM analysis for mineral surface. There was a significant difference between the behavior of the fungal and bacterial species in dissolution of biotite. This difference may be due to the variation of these microorganisms in their mechanics of interaction with mineral surface. It was observed also that these microorganisms directly and indirectly induce biotite dissolution. Defining soil as a system driven by biological mechanisms rather than chemical processes has major implications for our understanding of how the system functions and how it will respond to changing conditions.

  • 2113.
    Ahmed, Engy
    et al.
    Stockholm University, Faculty of Science, Department of Geological Sciences.
    Holmström, Sara
    Stockholm University, Faculty of Science, Department of Geological Sciences.
    THE MICROBE-MINERAL INTERACTIONS IN THE ACIDIC PODZOL SOIL2013In: Mineralogical magazine, ISSN 0026-461X, E-ISSN 1471-8022, Vol. 77, no 5, p. 564-Article in journal (Other (popular science, discussion, etc.))
    Abstract [en]

    Iron is a key component of the chemical architecture of the biosphere. Due to the low bioavailability of iron in the environment, microorganisms have developed specific uptake strategies, like siderophores, which are operationally defined as low-molecular-mass biogenic Fe(III)-binding compounds, that can increase iron’s bioavailability by promoting the dissolution of iron-bearing minerals. In the present study, we aimed to investigate the composition of hydroxamate siderophores in the soil horizons of the acidic podzol, and study how they are affected by the presence of specific mineral types and microbial communities.

     Three different minerals (apatite, biotite and oligioclase) were inserted in the soil horizons (O (organic), E (eluvial), B (upper illuvial), and C (mineral)). After two years, soil samples were collected from both the bulk soil (next to the minerals) and from the soil attached to the mineral surfaces. The concentration of ten different fungal tri-hydroxamates and five bacterial ones were determined by high-performance liquid chromatography coupled to electrospray ionization mass spectrometry (HPLC-ESI-MS). In addition, total microbial composition and diversity were studied.

    Our field experiment succeeded in describing the relationship between the presence of siderophores, soil horizon and mineral type, in addition to understanding the interaction between mineral type and soil microbial composition. A wide range of fungal and bacterial hydroxamates were detected throughout the soil profile. On the other hand, the presence of the minerals completely altered the diversity of siderophores. In addition, each mineral had a unique interaction with hydroxamates in the different soil horizons. There were also a good relationship between the microbial diversity and the siderophore distribution. 

  • 2114.
    Ahmed, Engy
    et al.
    Stockholm University, Faculty of Science, Department of Geological Sciences.
    Holmström, Sara
    Stockholm University, Faculty of Science, Department of Geological Sciences.
    The Roles and Applications of Siderophores in Natural Environments2013Conference paper (Other academic)
    Abstract [en]

    Siderophores are organic compounds with low molecular mass that are produced by microorganisms growing under conditions of low iron. The primary function of these compounds is to chelate ferric iron from different terrestrial and aquatic habitats and thereby make it available for microbial cells.

    Siderophores have received much attention in recent years because of their potential roles and applications in various areas of environmental research. For instance, the production of siderophores can provide a quick identification of microbes to the species level that called “siderotyping”. On the other hand, siderophores could also function as biocontrol, biosensor, and bioremediation agents, in addition to their important role in mineral weathering and enhancing plant growth. In the present study, we aimed to investigate the composition of trihydroxamate siderophores in soil samples from different horizons (O (organic), E (eluvial), B (upper illuvial), and C (parent material)) of a podzol soil in Sweden, and study how they are affected by the presence of specific mineral types (apatite, biotite and oligioclase) that were inserted in the soil for two years in a field experiment.

    Our field experiment succeeded in describing the relationship between the presence of siderophores, soil horizons and mineral types. A wide range of fungal and bacterial hydroxamates were detected throughout the soil profile. On the other hand, the presence of the minerals completely altered the diversity of siderophores. In addition, each mineral had a unique interaction with hydroxamates in the different soil horizons. Our next step is to gain greater insight into the siderotyping to illustrate the relationship between the siderophore types that was found throughout the soil profile and on the different mineral surfaces and the microbial diversity by using metagenomic applications.

  • 2115.
    Ahmed, Engy
    et al.
    Stockholm University, Faculty of Science, Department of Geological Sciences.
    Holmström, Sara
    Stockholm University, Faculty of Science, Department of Geological Sciences.
    Brüchert, Volker
    Stockholm University, Faculty of Science, Department of Geological Sciences.
    Holm, Nils G.
    Stockholm University, Faculty of Science, Department of Geological Sciences.
    The Role of Microorganisms in the diversity and distribution of siderophores in Podzolic Forest Soil2013In: Mineralogical magazine, ISSN 0026-461X, E-ISSN 1471-8022, Vol. 77, no 2, p. 161--208(48)Article in journal (Other academic)
    Abstract [en]

    Iron is a key component of the chemical architecture of the biosphere. Due to the low bioavailability of iron in the environment, microorganisms have developed specific uptake strategies. The most important one is the production of siderophores, which are operationally defined as low-molecular-mass biogenic Fe (III)-binding compounds which may greatly increase bioavailability of Fe [1]. One of the primary biogeochemical functions of siderophores is therefore to increase Fe bioavailability by promoting the dissolution of iron-bearing minerals [2]. This study aims to understand the role of microorganisms in the chemical diversity and distribution of siderophores in podzol soil and how this diversity can contribute to the bioavailability of Fe in forest soil.Soil samples were collected from an experimental site in the area of Bispgården in central Sweden (63°07′N, 16°70′E) from the O (organic), E (eluvial), B1 (upper illuvial), and C (mineral) horizons. Concentration and chemical composition of dissolved and adsorbed siderophores in the soil samples were determined using colorimetric assays and high-performance liquid chromatography.The highest siderophore concentrations were found in the O layer and thereafter decreased by depth. Concentrations of dissolved hydroxamate, catecholate and carboxylate siderophores were up to 84, 17 and 0.2 nmol/ g soil, respectively. In contrast, concentrations of adsorbed hydroxamates, catecholates and carboxylates were only up to 1.8, 3 and 0.2 nmol/ g soil, respectively.Siderophore-producing microorganisms were isolated from the same soil samples. Viable fungi, bacteria and actinomycete counts ranged from 7 to 300, from 300 to 1800, and from 0 to 5 cfu/gm, respectively. The highest counts were found in the O and E layers. Only the E layer contained the three types of siderophore-producing microorganisms investigated in this study. Siderophores were extracted from culture filtrates of the isolated microorganisms when grown under iron-limited conditions. These extracts varied considerably in siderophore composition. Fungal isolates produced up to 183 μM of hydroxamates, especially those isolated from the O layer, whereas bacteria and actinomycete isolated from the O and E layers of the soil produced high amounts of carboxylate, catecholate and hydroxamate siderophores. Actinomycete produced up to 93 μM of hydroxamates and 47 μM of catecholates, while bacteria produced up to 34 μM of carboxylates and up to 14 μM of catecholates.The depth variability in concentration and chemical composition and the good correlation between abundance of siderophore-producing microorganisms and siderophore soil concentrations strongly suggest that these siderophore-producing microorganisms play an important role in the mobilization of iron in the podzol soil that may be important in iron availability to plants in forest environment.

    [1] Clay et al. (1981) Biochemistry 20, 2432-2436. [2] Duckworth et al. (2009) ChemGeol 260, 149-158.

  • 2116.
    Ahmed, Engy
    et al.
    Stockholm University, Faculty of Science, Department of Geological Sciences.
    Holmström, Sara J. M.
    Stockholm University, Faculty of Science, Department of Geological Sciences.
    Microbe-mineral interactions: The impact of surface attachment on mineral weathering and element selectivity by microorganisms2015In: Chemical Geology, ISSN 0009-2541, E-ISSN 1872-6836, Vol. 403, p. 13-23Article in journal (Refereed)
    Abstract [en]

    One of the major gaps within the field of biogeochemistry is the lack of a detailed and deep understanding of the mechanismbehind the microbial inducement of mineral dissolution. The association of microorganisms with the mineral surfaces is an important issue for understanding processes like mineral weathering, biomineralization, bioremediation and biofouling. The present study aims to investigate the performance of attached and unattached soil fungal and bacterial species in biotite weathering and in the selectivity of elements from biotite. Sterilized microplate devices were filled with biotite (>2 mm) followed by an iron limited liquid growth medium and were inoculated separately with six different microbial species isolated from podzol soil: Erwinia amylovora, Pseudomonas stutzeri, Pseudomonas mendocina, Streptomyces pilosus, Neurospora crassa and Penicillium melinii. The experiment was designed in two set-ups: 1) attached form, in which the microorganisms were inoculated directly to the biotite surface, and 2) unattached form, in which 0.4 mu m PET track etched devices were used to separate the microbial cells from the biotite surface. Our findings indicate that the surface attached microorganisms led to a greater dissolution of elements from biotite than the unattached microorganisms that was evidenced by 1) higher dissolution of Fe, Al and Si, 2) greater decrease in pH of the liquid growth medium, and 3) relatively higher production of siderophores. Furthermore, there was no significant difference in the capability of element selectivity between the attached and unattached microbial forms. The biotite dissolution was promoted initially by complexation processes and later by acidification processes for most of the attached and unattached microorganisms. Thus, we conclude that despite the mineral dissolution induced by microbial attachment on the mineral surface, the element composition of the biotite and nutritional need of the microorganisms were the main factors affecting the element selectivity.

  • 2117.
    Ahmed, Engy
    et al.
    Stockholm University, Faculty of Science, Department of Geological Sciences.
    Holmström, Sara J. M.
    Stockholm University, Faculty of Science, Department of Geological Sciences.
    Siderophore Production by Microorganisms Isolated From a Podzol Soil Profile2015In: Geomicrobiology Journal, ISSN 0149-0451, E-ISSN 1521-0529, Vol. 32, no 5, p. 397-411Article in journal (Refereed)
    Abstract [en]

    Siderophore-producing bacteria/actinobacteria and fungi were isolated from O- (organic), E- (eluvial), B- (upper illuvial), and C- (parent material) horizons of podzol soil. Siderophores were isolated and hydroxamate type siderophores were detected and quantitated by high-performance liquid chromatography coupled to electrospray ionization mass spectrometry. The molecular identification of siderophore-producing isolates showed that there was a high diversity of fungal and bacterial/actinobacterial species throughout the soil profile. The isolated bacteria/actinobacteria showed different abilities in the production of ferrioxamines (E, B, G and D). Moreover, the isolated fungal species showed great variety in the production of ferrichromes, coprogens and fusarinines.

  • 2118.
    Ahmed, Engy
    et al.
    Stockholm University, Faculty of Science, Department of Geological Sciences.
    Holmström, Sara J. M.
    Stockholm University, Faculty of Science, Department of Geological Sciences.
    Siderophores in environmental research: roles and applications2014In: Microbial Biotechnology, ISSN 1751-7907, E-ISSN 1751-7915, Vol. 7, no 3, p. 196-208Article, review/survey (Refereed)
    Abstract [en]

    Siderophores are organic compounds with low molecular masses that are produced by microorganisms and plants growing under low iron conditions. The primary function of these compounds is to chelate the ferric iron [Fe(III)] from different terrestrial and aquatic habitats and thereby make it available for microbial and plant cells. Siderophores have received much attention in recent years because of their potential roles and applications in various areas of environmental research. Their significance in these applications is because siderophores have the ability to bind a variety of metals in addition to iron, and they have a wide range of chemical structures and specific properties. For instance, siderophores function as biocontrols, biosensors, and bioremediation and chelation agents, in addition to their important role in weathering soil minerals and enhancing plant growth. The aim of this literature review is to outline and discuss the important roles and functions of siderophores in different environmental habitats and emphasize the significant roles that these small organic molecules could play in applied environmental processes.

  • 2119.
    Ahmed, Engy
    et al.
    Stockholm University, Faculty of Science, Department of Geological Sciences.
    Holmström, Sara J. M.
    Stockholm University, Faculty of Science, Department of Geological Sciences.
    The effect of soil horizon and mineral type on the distribution of siderophores in soil2014In: Geochimica et Cosmochimica Acta, ISSN 0016-7037, E-ISSN 1872-9533, Vol. 131, p. 184-195Article in journal (Refereed)
    Abstract [en]

    Iron is a key component of the chemical architecture of the biosphere. Due to the low bioavailability of iron in the environment, microorganisms have developed specific uptake strategies like production of siderophores. Siderophores are operationally defined as low-molecular-mass biogenic Fe(III)-binding compounds, that can increase the bioavailability of iron by promoting the dissolution of iron-bearing minerals. In the present study, we investigated the composition of dissolved and adsorbed siderophores of the hydroxamate family in the soil horizons of podzol and the effect of specific mineral types on siderophores. Three polished mineral specimens of 3 cm x 4 cm x 3 mm (apatite, biotite and oligioclase) were inserted in the soil horizons (O (organic), E (eluvial) and B (upper illuvial)). After two years, soil samples were collected from both the bulk soil of the whole profile and from the soil attached to the mineral surfaces. The concentration of ten different fungal tri-hydroxamates within ferrichromes, fusigen and coprogens families, and five bacterial hydroxamates within the ferrioxamine family were detected. All hydroxamate types were determined in both soil water (dissolved) and soil methanol (adsorbed) extracts along the whole soil profile by high-performance liquid chromatography coupled to electrospray ionization mass spectrometry (HPLC-ESI-MS); hence, the study is the most extensive of its kind. We found that coprogens and fusigen were present in much higher concentrations in bulk soil than were ferrioxamines and ferrichromes. On the other hand, the presence of the polished mineral completely altered the distribution of siderophores. In addition, each mineral had a unique interaction with the dissolved and adsorbed hydroxamates in the different soil horizons. Thus siderophore composition in the soil environment is controlled by the chemical, physical and biological characteristics of each soil horizon and also by the available mineral types.

  • 2120.
    Ahmed, Engy
    et al.
    Stockholm University, Faculty of Science, Department of Geological Sciences.
    Hugerth, Luisa W.
    Logue, Jurg B.
    Brüchert, Volker
    Stockholm University, Faculty of Science, Department of Geological Sciences.
    Andersson, Anders F.
    Holmström, Sara J. M.
    Stockholm University, Faculty of Science, Department of Geological Sciences.
    Mineral Type Structures Soil Microbial Communities2017In: Geomicrobiology Journal, ISSN 0149-0451, E-ISSN 1521-0529, Vol. 34, no 6, p. 538-545Article in journal (Refereed)
    Abstract [en]

    Soil microorganisms living in close contact with minerals play key roles in the biogeochemical cycling of elements, soil formation, and plant nutrition. Yet, the composition of microbial communities inhabiting the mineralosphere (i.e., the soil surrounding minerals) is poorly understood. Here, we explored the composition of soil microbial communities associated with different types of minerals in various soil horizons. To this effect, a field experiment was set up in which mineral specimens of apatite, biotite, and oligoclase were buried in the organic, eluvial, and upper illuvial horizons of a podzol soil. After an incubation period of two years, the soil attached to the mineral surfaces was collected, and microbial communities were analyzed by means of Illumina MiSeq sequencing of the 16S (prokaryotic) and 18S (eukaryotic) ribosomal RNA genes. We found that both composition and diversity of bacterial, archaeal, and fungal communities varied across the different mineral surfaces, and that mineral type had a greater influence on structuring microbial assemblages than soil horizon. Thus, our findings emphasize the importance of mineral surfaces as ecological niches in soils.

  • 2121.
    Ahmed, Engy
    et al.
    Stockholm University, Faculty of Science, Department of Geological Sciences. Stockholm University, Science for Life Laboratory (SciLifeLab).
    Parducci, Laura
    Unneberg, Per
    Ågren, Rasmus
    Schenk, Frederik
    Stockholm University, Faculty of Science, Department of Geological Sciences.
    Rattray, Jayne E.
    Stockholm University, Faculty of Science, Department of Geological Sciences.
    Han, Lu
    Muschitiello, Francesco
    Stockholm University, Faculty of Science, Department of Geological Sciences. Columbia University, USA.
    Pedersen, Mikkel W.
    Smittenberg, Rienk H.
    Stockholm University, Faculty of Science, Department of Geological Sciences.
    Afrifa Yamoah, Kweku
    Stockholm University, Faculty of Science, Department of Geological Sciences.
    Slotte, Tanja
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences. Stockholm University, Science for Life Laboratory (SciLifeLab).
    Wohlfarth, Barbara
    Stockholm University, Faculty of Science, Department of Geological Sciences.
    Archaeal community changes in Lateglacial lake sediments: Evidence from ancient DNA2018In: Quaternary Science Reviews, ISSN 0277-3791, E-ISSN 1873-457X, Vol. 181, p. 19-29Article in journal (Refereed)
    Abstract [en]

    The Lateglacial/early Holocene sediments from the ancient lake at Hasseldala Port, southern Sweden provide an important archive for the environmental and climatic shifts at the end of the last ice age and the transition into the present Interglacial. The existing multi-proxy data set highlights the complex interplay of physical and ecological changes in response to climatic shifts and lake status changes. Yet, it remains unclear how microorganisms, such as Archaea, which do not leave microscopic features in the sedimentary record, were affected by these climatic shifts. Here we present the metagenomic data set of Hasseldala Port with a special focus on the abundance and biodiversity of Archaea. This allows reconstructing for the first time the temporal succession of major Archaea groups between 13.9 and 10.8 ka BP by using ancient environmental DNA metagenomics and fossil archaeal cell membrane lipids. We then evaluate to which extent these findings reflect physical changes of the lake system, due to changes in lake-water summer temperature and seasonal lake-ice cover. We show that variations in archaeal composition and diversity were related to a variety of factors (e.g., changes in lake water temperature, duration of lake ice cover, rapid sediment infilling), which influenced bottom water conditions and the sediment-water interface. Methanogenic Archaea dominated during the Allerod and Younger Dryas pollen zones, when the ancient lake was likely stratified and anoxic for large parts of the year. The increase in archaeal diversity at the Younger Dryas/Holocene transition is explained by sediment infilling and formation of a mire/peatbog.

  • 2122.
    Ahmed, Ishtiaq
    Stockholm University, Faculty of Social Sciences, Department of Political Science.
    34 entries including on ideology, Islamic state, personalities, Muslim community, Islamic law and so on2012In: The Oxford Companion to Pakistani History / [ed] Ayesha Jalal, Karachi: Oxford University Press, 2012, , p. 558Chapter in book (Other academic)
  • 2123.
    Ahmed, Ishtiaq
    Stockholm University, Faculty of Social Sciences, Department of Political Science.
    Abdullahi An-Naim on Constitutional and Human Rights Issues1993In: Islamic Law Reform and Human Rights, Oslo: Nordic Human Rights Publications , 1993Chapter in book (Other academic)
  • 2124.
    Ahmed, Ishtiaq
    Stockholm University, Faculty of Social Sciences, Department of Political Science.
    Ethnicity abd Separatist Movements in South Asia1993In: Formation of Identity and Dynamics of Conflict in the 1990s, Göteborg: Nordnes , 1993Chapter in book (Other academic)
  • 2125.
    Ahmed, Ishtiaq
    Stockholm University, Faculty of Social Sciences, Department of Political Science.
    Exit, Voice and Citizenship1997In: International Migration, Immobility and Development: Multidisciplinary Perspectives, Oxford and New York: Berg Publishers , 1997Chapter in book (Other academic)
  • 2126.
    Ahmed, Ishtiaq
    Stockholm University, Faculty of Social Sciences.
    Globalisation and Human Rights in Pakistan2002In: Journal of Punjab Studies, Vol. 9, no 1, p. 57-89Article in journal (Refereed)
  • 2127.
    Ahmed, Ishtiaq
    Stockholm University, Faculty of Social Sciences, Department of Political Science.
    Group Representation in a Democracy?2007In: Utsikt mot utveckling: Equal Representation. A Challenge to Democracy and Democracy Promotion, no 29, p. 73-90Article in journal (Other academic)
  • 2128.
    Ahmed, Ishtiaq
    Stockholm University, Faculty of Social Sciences, Department of Political Science.
    Hamdard1995In: Encyclopedia of the Modern Islamic World, New York: Oxford University Press , 1995Chapter in book (Other academic)
  • 2129.
    Ahmed, Ishtiaq
    Stockholm University, Faculty of Social Sciences.
    Islam and Pan-Arabism in the Gulf Crisis1991Report (Other (popular science, discussion, etc.))
  • 2130.
    Ahmed, Ishtiaq
    Stockholm University, Faculty of Social Sciences.
    Looking backwards into the future: A Critique of Islamic Modernism2002In: Journal of Futures Studies, ISSN 1027-6084, Vol. 7, no 2, p. 75-96Article in journal (Refereed)
  • 2131.
    Ahmed, Ishtiaq
    Stockholm University, Faculty of Social Sciences.
    Pakistan's National Identity2008In: International Review of Modern Sociology, ISSN 0973-2047, Vol. 34, no 1, p. 47-59Article in journal (Refereed)
  • 2132.
    Ahmed, Ishtiaq
    Stockholm University, Faculty of Social Sciences, Department of Political Science.
    Politics of Ethncity, and the Rise of Separatist Movements in South Asia1992In: When Democracy Makes Sense, Uppsala: AKUT , 1992Chapter in book (Other academic)
  • 2133.
    Ahmed, Ishtiaq
    Stockholm University, Faculty of Social Sciences.
    Radicalization and De-Radicalization in Singapore and Pakistan: A Comparison2009In: Conflict and peace studies, ISSN 2072-0408, Vol. 2, no 3, p. 43-59Article in journal (Refereed)
  • 2134.
    Ahmed, Ishtiaq
    Stockholm University, Faculty of Social Sciences, Department of Political Science.
    Religious Nationalism and Sikhism1996In: Questioning the Secular State: The Worldwide Resurgence of Religion in Politics, London: Hurst & Company , 1996Chapter in book (Other academic)
  • 2135.
    Ahmed, Ishtiaq
    Stockholm University, Faculty of Social Sciences.
    SAARC social charter: a comparison of state and civil society standpoints on human security2010In: The emerging dimensions of SAARC / [ed] Sukh Deo Muni, New Delhi: Foundation Books , 2010, p. 132-153Chapter in book (Refereed)
  • 2136.
    Ahmed, Ishtiaq
    Stockholm University, Faculty of Social Sciences, Department of Political Science.
    Sikherna och sikhisk nationalism1994In: Stat, Nation och Nationalism i Asien, Uppsala: Sällskapet för asienstudier , 1994Chapter in book (Other academic)
  • 2137.
    Ahmed, Ishtiaq
    Stockholm University, Faculty of Social Sciences, Department of Political Science.
    South Asia1999In: Islam Outside the Arab World, Richmond: Curzon Press , 1999Chapter in book (Other academic)
  • 2138.
    Ahmed, Ishtiaq
    Stockholm University, Faculty of Social Sciences.
    State, nation and ethnicity in contemporary South Asia1996Book (Other academic)
  • 2139.
    Ahmed, Ishtiaq
    Stockholm University, Faculty of Social Sciences.
    State, nation and ethnicity in contemporary South Asia1998 (ed. New ed.)Book (Other academic)
  • 2140.
    Ahmed, Ishtiaq
    Stockholm University, Faculty of Social Sciences, Department of Political Science.
    Sydasiatisk islam: Konfronation mellan gamla värderingar och nya realitet1994In: Majoritetens Islam: Om Muslimer utanför Arabvärlden, Stockholm: Arena , 1994Chapter in book (Other academic)
  • 2141.
    Ahmed, Ishtiaq
    Stockholm University, Faculty of Social Sciences, Department of Political Science.
    The 1947 partition of Punjab: Arguments put forth before the Punjab Boundary Commission by the parties involved1999In: Region and partition: Bengal, Punjab and the partition of the subcontinent / [ed] Ian Talbot, Gurharpal Singh, Oxford: Oxford University Press, 1999, p. 116-167Chapter in book (Other academic)
  • 2142.
    Ahmed, Ishtiaq
    Stockholm University.
    The Concept of an Islamic State: An Analysis of the Ideological Controversy in Pakistan1985Doctoral thesis, monograph (Other academic)
  • 2143.
    Ahmed, Ishtiaq
    Stockholm University.
    The concept of an Islamic state: an analysis of the ideological controversy in Pakistan1987Book (Refereed)
  • 2144.
    Ahmed, Ishtiaq
    Stockholm University, Faculty of Social Sciences, Department of Political Science.
    The Cultural and Political Heritage of Sri Lanka2007In: Utsikt mot utveckling: Equal Representation. A Challenge to Democracy and Democracy Promotion, no 29, p. 119-130Article in journal (Other academic)
  • 2145.
    Ahmed, Ishtiaq
    Stockholm University, Faculty of Social Sciences, Department of Political Science.
    The India-Pakistan Imbroglio: Time to Change Course2012In: FPRC Journal, ISSN 2277-2464, no 9, p. 63-84Article in journal (Refereed)
  • 2146.
    Ahmed, Ishtiaq
    Stockholm University, Faculty of Social Sciences, Department of Political Science.
    The Kashmir Dispute: Is There an Important Hydropolitical Dimension to It?1998In: Hydropolitik och Demokrati, Uppsala: Sällskapet för asienstudier , 1998Chapter in book (Other academic)
  • 2147.
    Ahmed, Ishtiaq
    Stockholm University, Faculty of Social Sciences, Department of Political Science.
    The Lahore film industry: a historical sketch2012In: Travels of Bollywood cinema: from Bombay to LA / [ed] Anjali Gera Roy, Chua Beng Huat, New Delhi: Oxford University Press, 2012, p. 55-77Chapter in book (Refereed)
    Abstract [en]

    This chapter presents a sweeping historical overview of the flows between Lahore and Bombay before and after 1947. It shows how two major factors — Partition and the rise of Islam in Pakistan — led to the premature demise of a nascent film industry emerging around the Bhati Gate area in Lahore, despite the in-migration of Muslim talent from Bombay. It calls attention to the shared cultural memories that attest to the presence of Lahore in Bombay and Bombay in Lahore. It argues that in view of its pre-eminent position as the centre of Hindi /Urdu culture, Lahore would have emerged as a strong competitor to Bombay had Partition not occurred. However, it can still become a major production centre for Punjabi films that can cater to a transnational Punjabi population.

  • 2148.
    Ahmed, Ishtiaq
    Stockholm University, Faculty of Social Sciences, Department of Political Science.
    The Nature and Structure of Ethnic Conflict and Separatist Movements in South Asia1998In: People's Rights: Social Movements and the State in The Third World., New Delhi/Thousand Oaks/London: Sage Publications , 1998Chapter in book (Other academic)
  • 2149.
    Ahmed, Ishtiaq
    Stockholm University, Faculty of Social Sciences.
    The Pakistan Islamic state project: a secular critique2010In: State and secularism: perspectives from Asia / [ed] Michael Heng Siam-Heng and Ten Chin Liew, Hackensack, N.J.: World Scientific, 2010, p. 185-211Chapter in book (Refereed)
  • 2150.
    Ahmed, Ishtiaq
    Stockholm University, Faculty of Social Sciences.
    The politics of religion in South and Southeast Asia2011Collection (editor) (Refereed)
40414243444546 2101 - 2150 of 104469
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