986 research outputs found

    The potential role of ePortfolios in the Teaching Excellence Framework

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    Current debates on HE policy in the UK are dominated by the evolving Teaching Excellence Framework (TEF) which will soon involve the government establishing key metrics.  In this context, and seizing this valuable moment in policy formation, we here provide a brief foray into the multiple aspects of ‘teaching excellence’ (TE) as a basis to highlight both the complexity of identifying ways to measure it and the shortcomings of existing official developments.  In the absence of a clear conceptual understanding of the learning processes and the role of teaching which apparently underpins the TEF, we present a model of the learning process to which the indicators currently proposed by the authorities can be related.  We propose that ePortfolios can play a special role in the TEF in capturing the qualitative outcomes of learning processes which, importantly, reflect the student perspective in terms of goals, learning experiences and achievement.  These are both crucial yet missing elements of the proposals to date. Finally, we provide some examples of how information from ePortfolios could be used by HE institutions to enhance their institutional submissions to the TEF.

    Positive Changes in Regional Vegetation Cover in Patagonia Shown by MARAS Monitoring System

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    MARAS (Environmental monitoring of arid and semiarid lands) is a vegetation and soil monitoring system in Patagonia, a 700.000 km2 area in southern South America. Installed between 2008-2015 within INTA-Argentina and INIA-Chile national agricultural research institutes, it includes photographs, 500-point intercepts, 50-m canfield lines to detect patches, 10 land function observations and 0-10 cm soil samples in 458 ground sites. Data is centralized and freely accessible https://maras.inta.gob.ar. We analysed changes based in the first 255 reassessments made at 5-year intervals. At a regional scale significant changes (P \u3c 0.05 paired T test) were detected for: perennial vegetation cover, that was originally 42% and increased +3.1%. Plant species richness of 13.7 species/monitor increased +0.7, bare soil of 35% decreased -7.9%. Length of bare soil interpatches was 157 cm and decreased -42 cm. Land function indexes of Stability 46.2%, Infiltration 45.1% and Recycling 31.0% showed small non-significant changes (-1.3, +0.7 and +1.42 respectively). Significant changes in soils under vegetated patches were: conductivity 0.59 dS/m increased +0.49, and pH 7.3 +0.33. Organic matter was 2.0% and increased 0.35%, and sand was 73% and increased 3%. Finer soil particles decreased non-significantly. Bare soil interpatches had 1.4% organic matter and also increased 0.33%, and clay, that initially was 9.3% reduced -2.3%. The long-term ground sites provide a means to monitor slow changes in these rangelands in relation to global climatic change and regional grazing patterns. Patagonia has currently the lowest domestic stocking rates of the last century and vegetation seems to be slowly growing in perennial cover, with significant reductions in exposed bare soil, increase in biodiversity and soil organic carbon

    Rare top decay t-> c l+l- as a probe of new physics

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    The rare top decay t-> c l+l-, which involves flavor violation, is studied as a possible probe of new physics. This decay is analyzed with the simplest Standard Model extensions with additional gauge symmetry formalism. The considered extension is the Left-Right Symmetric Model, including a new neutral gauge boson Z' that allows to obtain the decay at tree level through Flavor Changing Neutral Currents (FCNC) couplings. The neutral gauge boson couplings are considered diagonal but family non-universal in order to induce these FCNC. We find the $BR(t-> c l+l-)~10^{-13} for a range 1 TeV < M_{Z'} < 3 TeV.Comment: 9 pages, 6 figure

    Neutrino mixing and masses in a left-right model with mirror fermions

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    In the framework of a left-right model containing mirror fermions with gauge group SU(3)CSU(2)LSU(2)RU(1)Y_{C} \otimes SU(2)_{L} \otimes SU(2)_{R} \otimes U(1)_{Y^\prime}, we estimate the neutrino masses, which are found to be consistent with their experimental bounds and hierarchy. We evaluate the decay rates of the Lepton Flavor Violation (LFV) processes μeγ\mu \rightarrow e \gamma, τμγ\tau \rightarrow \mu \gamma and τeγ\tau \rightarrow e\gamma. We obtain upper limits for the flavor-changing branching ratios in agreement with their present experimental bounds. We also estimate the decay rates of heavy Majorana neutrinos in the channels NW±lN \rightarrow W^{\pm} l^{\mp}, NZνlN \rightarrow Z \nu_{l} and NHνlN \rightarrow H \nu_{l}, which are roughly equal for large values of the heavy neutrino mass. Starting from the most general Majorana neutrino mass matrix, the smallness of active neutrino masses turns out from the interplay of the hierarchy of the involved scales and the double application of seesaw mechanism. An appropriate parameterization on the structure of the neutrino mass matrix imposing a symmetric mixing of electron neutrino with muon and tau neutrinos leads to Tri-bimaximal mixing matrix for light neutrinos.Comment: Accepted by European Physical Journal

    Ramsey numbers and adiabatic quantum computing

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    The graph-theoretic Ramsey numbers are notoriously difficult to calculate. In fact, for the two-color Ramsey numbers R(m,n)R(m,n) with m,n3m,n\geq 3, only nine are currently known. We present a quantum algorithm for the computation of the Ramsey numbers R(m,n)R(m,n). We show how the computation of R(m,n)R(m,n) can be mapped to a combinatorial optimization problem whose solution can be found using adiabatic quantum evolution. We numerically simulate this adiabatic quantum algorithm and show that it correctly determines the Ramsey numbers R(3,3) and R(2,s) for 5s75\leq s\leq 7. We then discuss the algorithm's experimental implementation, and close by showing that Ramsey number computation belongs to the quantum complexity class QMA.Comment: 4 pages, 1 table, no figures, published versio

    Microscopic Analysis of the Non-Dissipative Force on a Line Vortex in a Superconductor: Berry's Phase, Momentum Flows and the Magnus Force

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    A microscopic analysis of the non-dissipative force Fnd{\bf F}_{nd} acting on a line vortex in a type-II superconductor at T=0T=0 is given. We first examine the Berry phase induced in the true superconducting ground state by movement of the vortex and show how this induces a Wess-Zumino term in the hydrodynamic action ShydS_{hyd} of the superconducting condensate. Appropriate variation of ShydS_{hyd} gives Fnd{\bf F}_{nd} and variation of the Wess-Zumino term is seen to contribute the Magnus (lift) force of classical hydrodynamics to Fnd{\bf F}_ {nd}. This first calculation confirms and strengthens earlier work by Ao and Thouless which was based on an ansatz for the many-body ground state. We also determine Fnd{\bf F}_{nd} through a microscopic derivation of the continuity equation for the condensate linear momentum. This equation yields the acceleration equation for the superflow and shows that the vortex acts as a sink for the condensate linear momentum. The rate at which momentum is lost to the vortex determines Fnd{\bf F}_{nd} and the result obtained agrees with the Berry phase calculation. The Magnus force contribution to Fnd{\bf F}_{nd} is seen to be a consequence of the vortex topology. Preliminary remarks are made regarding finite temperature extensions, with emphasis on its relevance to the sign anomaly occurring in Hall effect experiments done in the flux flow regime.Comment: 40 pages, RevTex, UBCTP-94-00
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