855 research outputs found
Brave Forms of Mentoring Supported by Technology in Teacher Education
Indexación: Web of ScienceQuality education is undoubtedly a global concern, tied closely to preoccupations with economic and social development. Increasingly, the adoption and effective use of current technology tools are being recognized as visible signs of that quality. Scholars are providing increasing evidence of the kinds of empowered teacher identities that will adopt the effective use of technology tools in teaching. Less is being discussed about how technology can support the processes needed to mediate such identities. The context of Teacher Education is a strategic place to begin to initiate such processes. Our aim in this article is twofold: 1) to describe two recent examples of innovative, technology - supported mentoring processes that were conducted in the context of an EFL Teacher Education program in Chile; 2) to revisit the findings of these studies in light of new evidence from participants who have moved on in their careers. This evidence is viewed in the framework of recent scholarship on the responsibilities that Teacher Education plays in their development. The first 16-month study examined the influences of a guided reading program involving e-readers on the identities and literacy skills of pre-service teachers. The second was a student-conceived study. That inquiry sought to determine the influence of upper year students' peer mentoring, made available partly through a social media site (SMS), on the identities and investment in learning of 12 firs-year students in the pedagogy program. The initial evidence from ethnographic tools used in both studies indicated that the participants were struggling with confidence and doubting themselves as knowledgeable, effective future teachers - not predictive of a potential for quality teaching. Positive signs at the end of both studies and more recent reports from participants suggest that the mentoring had longitudinal benefits for some, although not uniformly. The potential of apprenticeship and mentoring in a technology-supported environment requires rethinking Teacher Education mandates if we are to empower emerging teachers to be quality teachers.http://www.ejel.org/issue/download.html?idArticle=48
SO(10) SUSY GUT for Fermion Masses : Lepton Flavor and CP Violation
We discuss the results of a global analysis of a simple SO(10) SUSY
GUT with family symmetry and low energy R parity. The model describes
fermion mass matrices with 14 parameters and gives excellent fits to 20
observable masses and mixing angles in both quark and lepton sectors, giving 6
predictions. Bi-large neutrino mixing is obtained with hierarchical quark and
lepton Yukawa matrices; thus avoiding the possibility of large lepton flavor
violation. The model naturally predicts small 1-3 neutrino mixing, with . In this paper we evaluate the predictions for
the lepton flavor violating processes, , and and also the electric dipole moment of the
electron, , muon and tau, assuming universal squark and slepton masses,
, and a universal soft SUSY breaking A parameter, , at the GUT
scale. We find is naturally below present bounds, but
may be observable by MEG. Similarly, is below present bounds; but is
within the range of future experiments. We also give predictions for the light
Higgs mass (using FeynHiggs). We find an upper bound given by
GeV, with an estimated GeV theoretical uncertainty. Finally we present
predictions for SUSY particle masses in the favored region of parameter space.Comment: 25 pages, 18 figures, several typos in captions of tables 2 and 3
corrected, acknowledgments adde
A solution to the mu problem in the presence of a heavy gluino LSP
In this paper we present a solution to the problem in an SO(10)
supersymmetric grand unified model with gauge mediated and D-term supersymmetry
breaking. A Peccei-Quinn symmetry is broken at the messenger scale GeV and enables the generation of the term. The boundary
conditions defined at lead to a phenomenologically acceptable version of
the minimal supersymmetric standard model with novel particle phenomenology.
Either the gluino or the gravitino is the lightest supersymmetric particle
(LSP). If the gravitino is the LSP, then the gluino is the next-to-LSP (NLSP)
with a lifetime on the order of one month or longer. In either case this heavy
gluino, with mass in the range 25 - 35 GeV, can be treated as a stable particle
with respect to experiments at high energy accelerators. Given the extensive
phenomenological constraints we show that the model can only survive in a
narrow region of parameter space resulting in a light neutral Higgs with mass
GeV and . In addition the lightest stop
and neutralino have mass GeV and GeV,
respectively. Thus the model will soon be tested. Finally, the invisible axion
resulting from PQ symmetry breaking is a cold dark matter candidate.Comment: 30 pages, 9 figure
Can multi-TeV (top and other) squarks be natural in gauge mediation?
We investigate whether multi-TeV (1-3 TeV) squarks can be natural in models
of gauge mediated SUSY breaking. The idea is that for some boundary condition
of the scalar (Higgs and stop) masses, the Higgs (mass), evaluated at the
renormalization scale GeV, is not very sensitive to (boundary
values of) the scalar masses (this has been called ``focussing'' in recent
literature). Then, the stop masses can be multi-TeV without leading to
fine-tuning in electroweak symmetry breaking. {\em Minimal} gauge mediation
does {\em not} lead to this focussing (for all values of and the
messenger scale): the (boundary value of) the Higgs mass is too small compared
to the stop masses. Also, in minimal gauge mediation, the gaugino masses are of
the same order as the scalar masses so that multi-TeV scalars implies multi-TeV
gauginos (especially gluino) leading to fine-tuning. We discuss ideas to {\em
increase} the Higgs mass relative to the stop masses (so that focussing can be
achieved) and also to {\em suppress} gaugino masses relative to scalar masses
(or to modify the gaugino mass relations) in {\em non-minimal} models of gauge
mediation -- then multi-TeV (top and other) squarks can be natural. Specific
models of gauge mediation which incorporate these ideas and thus have squarks
(and in some cases, the gluino) heavier than a TeV without resulting in
fine-tuning are also studied and their collider signals are contrasted with
those of other models which have multi-TeV squarks.Comment: LaTeX, 29 pages, 9 eps figures. Replacing an earlier version. In
version 3, some references and a minor comment have been added and typos have
been correcte
String-derived D4 flavor symmetry and phenomenological implications
In this paper we show how some flavor symmetries may be derived from the
heterotic string, when compactified on a 6D orbifold. In the body of the paper
we focus on the family symmetry, recently obtained in
orbifold constructions. We show how this flavor symmetry constrains fermion
masses, as well as the soft SUSY breaking mass terms. Flavor symmetry breaking
can generate the hierarchy of fermion masses and at the same time the flavor
symmetry suppresses large flavor changing neutral current processes.Comment: 17 pages, no figur
Patterns of Dynamical Gauge Symmetry Breaking
We construct and analyze theories with a gauge symmetry in the ultraviolet of
the form , in which the vectorial, asymptotically free
gauge interaction becomes strongly coupled at a scale where the interaction
is weakly coupled and produces bilinear fermion condensates that dynamically
break the symmetry. Comparisons are given between Higgs and dynamical
symmetry breaking mechanisms for various models.Comment: 14 pages, late
Color Superconductivity from Supersymmetry
A supersymmetric composite model of color superconductivity is proposed.
Quarks and diquarks are dynamically generated as composite fields by a newly
introduced strong gauge dynamics. It is shown that the condensation of the
scalar component of the diquark supermultiplet occurs when the chemical
potential becomes larger than some critical value. We believe that the model
well captures aspects of the diquark condensate behavior and helps our
understanding of the diquark dynamics in real QCD. The results obtained here
might be useful when we consider a theory composed of quarks and diquarks.Comment: 4 pages, 2 figures, An error in Eq.(10) correcte
Trouble for MAC
We show that the next-to-leading corrections to the kernel of the gap
equation can be large and of opposite sign to the lowest order kernel, in the
presence of a gauge boson mass. This calls into question the reliability of the
Most Attractive Channel hypothesis.Comment: 8 pages, 1 figure, LaTe
Probing the nature of the seesaw in renormalizable SO(10)
We study the nature of the see-saw mechanism in the context of renormalizable
SO(10) with Higgs fields in the 10-plets and 126-plet representations, paying
special attention to the supersymmetric case. We discuss analytically the
situation for the second and third generations of fermions ignoring any CP
violating phase. It is shown that b-tau unification and large atmospheric
mixing angle strongly disfavor the dominance of the type I see-saw.Comment: 12 page
Heterotic Cosmic Strings
We show that all three conditions for the cosmological relevance of heterotic
cosmic strings, the right tension, stability and a production mechanism at the
end of inflation, can be met in the strongly coupled M-theory regime. Whereas
cosmic strings generated from weakly coupled heterotic strings have the well
known problems posed by Witten in 1985, we show that strings arising from
M5-branes wrapped around 4-cycles (divisors) of a Calabi-Yau in heterotic
M-theory compactifications, solve these problems in an elegant fashion.Comment: 25 pages, v2: section and references adde
- …