2,075 research outputs found

    Developing transferable management skills through Action Learning

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    There has been increasing criticism of the relevance of the Master of Business Administration (MBA) in developing skills and competencies. Action learning, devised to address problem-solving in the workplace, offers a potential response to such criticism. This paper offers an insight into one university’s attempt to integrate action learning into the curriculum. Sixty-five part-time students were questioned at two points in their final year about their action learning experience and the enhancement of relevant skills and competencies. Results showed a mixed picture. Strong confirmation of the importance of selected skills and competencies contrasted with weaker agreement about the extent to which these were developed by action learning. There was, nonetheless, a firm belief in the positive impact on the learning process. The paper concludes that action learning is not a panacea but has an important role in a repertoire of educational approaches to develop relevant skills and competencies

    A cyclopentadienyl functionalized silylene-a flexible ligand for Si- And C-coordination

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    The synthesis of a 1,2,3,4-tetramethylcyclopentadienyl (Cp4^{4}) substituted four-membered N-heterocyclic silylene [{PhC(NtBu) 2_{2}}Si(C5_{5}Me4_{4}H)] is reported first. Then, selected reactions with transition metal and a calcium precursor are shown. The proton of the Cp4_{4}-unit is labile. This results in two different reaction pathways: (1) deprotonation and (2) rearrangement reactions. Deprotonation was achieved by the reaction of [{PhC(NtBu) 2_{2}}Si(C5_{5}Me4_{4}H)] with suitable zinc precursors. Rearrangement to [{PhC(NtBu) 2_{2}}(C5_{5}Me4_{4})SiH], featuring a formally tetravalent silicon R2_{2}CSi(R′)-H unit, was observed when the proton of the Cp4^{4} ring was shifted from the Cp4^{4}-ring to the silylene in the presence of a Lewis acid. This allows for the coordination of the Cp4^{4}-ring to a calcium compound. Furthermore, upon reaction with transition metal dimers [MCl(cod)] 2_{2} (M = Rh, Ir; cod = 1,5-cyclooctadiene) the proton stays at the Cp4^{4}-ring and the silylene reacts as a sigma donor, which breaks the dimeric structure of the precursors

    Mitochondrial nucleoids maintain genetic autonomy but allow for functional complementation

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    Mitochondrial DNA (mtDNA) is packaged into DNA-protein assemblies called nucleoids, but the mode of mtDNA propagation via the nucleoid remains controversial. Two mechanisms have been proposed: nucleoids may consistently maintain their mtDNA content faithfully, or nucleoids may exchange mtDNAs dynamically. To test these models directly, two cell lines were fused, each homoplasmic for a partially deleted mtDNA in which the deletions were nonoverlapping and each deficient in mitochondrial protein synthesis, thus allowing the first unequivocal visualization of two mtDNAs at the nucleoid level. The two mtDNAs transcomplemented to restore mitochondrial protein synthesis but were consistently maintained in discrete nucleoids that did not intermix stably. These results indicate that mitochondrial nucleoids tightly regulate their genetic content rather than freely exchanging mtDNAs. This genetic autonomy provides a molecular mechanism to explain patterns of mitochondrial genetic inheritance, in addition to facilitating therapeutic methods to eliminate deleterious mtDNA mutations

    Fracton pairing mechanism for "strange" superconductors: Self-assembling organic polymers and copper-oxide compounds

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    Self-assembling organic polymers and copper-oxide compounds are two classes of "strange" superconductors, whose challenging behavior does not comply with the traditional picture of Bardeen, Cooper, and Schrieffer (BCS) superconductivity in regular crystals. In this paper, we propose a theoretical model that accounts for the strange superconducting properties of either class of the materials. These properties are considered as interconnected manifestations of the same phenomenon: We argue that superconductivity occurs in the both cases because the charge carriers (i.e., electrons or holes) exchange {\it fracton excitations}, quantum oscillations of fractal lattices that mimic the complex microscopic organization of the strange superconductors. For the copper oxides, the superconducting transition temperature TcT_c as predicted by the fracton mechanism is of the order of ∼150\sim 150 K. We suggest that the marginal ingredient of the high-temperature superconducting phase is provided by fracton coupled holes that condensate in the conducting copper-oxygen planes owing to the intrinsic field-effect-transistor configuration of the cuprate compounds. For the gate-induced superconducting phase in the electron-doped polymers, we simultaneously find a rather modest transition temperature of ∼(2−3)\sim (2-3) K owing to the limitations imposed by the electron tunneling processes on a fractal geometry. We speculate that hole-type superconductivity observes larger onset temperatures when compared to its electron-type counterpart. This promises an intriguing possibility of the high-temperature superconducting states in hole-doped complex materials. A specific prediction of the present study is universality of ac conduction for T≳TcT\gtrsim T_c.Comment: 12 pages (including separate abstract page), no figure

    Optical absorption and photoluminescence spectroscopy of the growth of silver nanoparticles

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    Results obtained from the optical absorption and photoluminescence (PL) spectroscopy experiments have shown the formation of excitons in the silver-exchanged glass samples. These findings are reported here for the first time. Further, we investigate the dramatic changes in the photoemission properties of the silver-exchanged glass samples as a function of postannealing temperature. Observed changes are thought to be due to the structural rearrangements of silver and oxygen bonding during the heat treatments of the glass matrix. In fact, photoelectron spectroscopy does reveal these chemical transformations of silver-exchanged soda glass samples caused by the thermal effects of annealing in a high vacuum atmosphere. An important correlation between temperature-induced changes of the PL intensity and thermal growth of the silver nanoparticles has been established in this Letter through precise spectroscopic studies.Comment: 15 pages,4 figures,PDF fil

    Dynamics of Quantum Phase Transition in an Array of Josephson Junctions

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    We study the dynamics of the Mott insulator-superfluid quantum phase transition in a periodic 1D array of Josephson junctions. We show that crossing the critical point diabatically i.e. at a finite rate with a quench time τQ\tau_Q induces finite quantum fluctuations of the current around the loop proportional to τQ−1/6\tau_Q^{-1/6}. This scaling could be experimentally verified with in array of weakly coupled Bose-Einstein condensates or superconducting grains.Comment: 4 pages in RevTex, 3 .eps figures; 2 references added; accepted for publication in Phys.Rev.Let

    Reflectionless tunneling in ballistic normal-metal--superconductor junctions

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    We investigate the phenomenon of reflectionless tunneling in ballistic normal-metal--superconductor (NS) structures, using a semiclassical formalism. It is shown that applied magnetic field and superconducting phase difference both impair the constructive interference leading to this effect, but in a qualitatively different way. This is manifested both in the conductance and in the shot noise properties of the system considered. Unlike diffusive systems, the features of the conductance are sharp, and enable fine spatial control of the current, as well as single channel manipulations. We discuss the possibility of conducting experiments in ballistic semiconductor-superconductor structures with smooth interfaces and some of the phenomena, specific to such structures, that could be measured. A general criterion for the barrier at NS interfaces, though large, to be effectively transparent to pair current is obtained.Comment: published versio

    Interweaving in hybrid methodologies

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    The paper will consider instances of the interweaving of theory and practice within drawing research, in order to suggest potential approaches to the development of hybrid methodologies in fine art practice-led research. The paper is written from the position of two current supervisors and creative research collaborators: Deborah Harty and Phil Sawdon (aka humhyphenhum from 2007), who historically were supervisee/supervisor. The paper will make reference to Harty's experience as a Ph.D. researcher undertaking practice-led research within a fine art context (completed 2010) and supervised by Sawdon. A discussion of Harty's hybrid methodology: action theoria, will provide an instance of the interweaving of theory and practice. Action theoria incorporates the cyclical and iterative process of action research – intention; action; review – with a process of theoria – the dialogue of both practice and theory's relationship to a given subject matter. Following this, the paper will discuss the interweaving of action theoria into humhyphenhum's collaborative research methodology: meaningful play. This interwoven methodology evolved during collaborative practice-led research projects from 2005 to the present. The paper will make reference to several of humhyphenhum's projects as a means to identify the interweaving of theory and practice within collaborative research. As current supervisors (2015), the paper will conclude with a discussion of how reflection on these experiences has informed our position as supervisors. We will consider, for example, how this has impacted on our ability, as individual supervisors, to offer insights into the interweaving of theory and practice, without defaulting to the position of compelling our supervisees to adopt our methodology

    Survey on Traditional Mangrove Crab Identification Methods of Filipino Fishermen

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    The Philippines is one of the largest producers of mangrove crabs in the industry, but only three of the four Scylla species exist in the country. As one of the largest mangrove crab exporters, Filipino crab farmers must distinguish their harvest before catching them for crab farming since the growth and needs of crabs depend heavily on their species group. To determine the accuracy of widely used local traditional methods, survey questions were distributed to 34 respondents around the Philippines through selected online platforms. Data gathered included local methods for identifying mangrove crabs based on traditional ecological knowledge and experiences of the local fishers interviewed. The study found that 70.58% of those polled identify the species of crabs by looking at their claws and 55.88% observe the color of the crabs. Furthermore, 41.17% of respondents consider the width and size of the shell, while 11.76% examine the crabs\u27 carapace. Unique methods to certain regions were reported, including observation of minor features and behavior of the crabs and reliance on texture, weight, and season. Difficulty in species identification of juvenile crabs has been reported but was also possible when the crabs turn 2-3 months old or grow to the size of a 5-peso coin or 5 centimeters. Feeding schedules and consistent pond management are also said as crucial tasks in growing mangrove crabs. The fishermen voiced out concerns and opinions regarding the technology development and government policies in the crab industry

    Double Field Theory Formulation of Heterotic Strings

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    We extend the recently constructed double field theory formulation of the low-energy theory of the closed bosonic string to the heterotic string. The action can be written in terms of a generalized metric that is a covariant tensor under O(D,D+n), where n denotes the number of gauge vectors, and n additional coordinates are introduced together with a covariant constraint that locally removes these new coordinates. For the abelian subsector, the action takes the same structural form as for the bosonic string, but based on the enlarged generalized metric, thereby featuring a global O(D,D+n) symmetry. After turning on non-abelian gauge couplings, this global symmetry is broken, but the action can still be written in a fully O(D,D+n) covariant fashion, in analogy to similar constructions in gauged supergravities.Comment: 28 pages, v2: minor changes, version published in JHE
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