93 research outputs found
Boom, slump, sudden stops, recovery, and policy options. Portugal and the Euro
Over the past 20 years, Portugal has gone through a boom, a slump, a sud- den stop, and now a recovery. Unemployment has decreased, but remains high, and output is still far below potential. Competitiveness has improved, but more is needed to keep the current account in check as the economy recovers. Private and public debt are high, both legacies of the boom, the slump and the sudden stop. Productiv- ity growth remains low. Because of high debt and low growth, the recovery remains fragile. We review the history and the main mechanisms at work. We then review a number of policy options, from fiscal consolidation to fiscal expansion, cleaning up of non-performing loans, labor market reforms, product market reforms, and euro exit. We argue that at this point, the main focus of macroeconomic policy should be twofold. The first is the treatment of non-performing loans, the second is product market reforms and reforms aimed at increasing micro-flexibility in the labor market. Symmetrically, we also argue that at this point, some policies would be undesirable, among them faster fiscal consolidation, measures aimed at decreasing nominal wages and prices, and euro exit.info:eu-repo/semantics/publishedVersio
LHC and lepton flavour violation phenomenology of a left-right extension of the MSSM
We study the phenomenology of a supersymmetric left-right model, assuming
minimal supergravity boundary conditions. Both left-right and (B-L) symmetries
are broken at an energy scale close to, but significantly below the GUT scale.
Neutrino data is explained via a seesaw mechanism. We calculate the RGEs for
superpotential and soft parameters complete at 2-loop order. At low energies
lepton flavour violation (LFV) and small, but potentially measurable mass
splittings in the charged scalar lepton sector appear, due to the RGE running.
Different from the supersymmetric 'pure seesaw' models, both, LFV and slepton
mass splittings, occur not only in the left- but also in the right slepton
sector. Especially, ratios of LFV slepton decays, such as Br()/Br() are sensitive to the
ratio of (B-L) and left-right symmetry breaking scales. Also the model predicts
a polarization asymmetry of the outgoing positrons in the decay , A ~ [0,1], which differs from the pure seesaw 'prediction' A=1$.
Observation of any of these signals allows to distinguish this model from any
of the three standard, pure (mSugra) seesaw setups.Comment: 43 pages, 17 figure
Supersymmetric mass spectra and the seesaw type-I scale
We calculate supersymmetric mass spectra with cMSSM boundary conditions and a
type-I seesaw mechanism added to explain current neutrino data. Using
published, estimated errors on SUSY mass observables for a combined LHC+ILC
analysis, we perform a theoretical analysis to identify parameter
regions where pure cMSSM and cMSSM plus seesaw type-I might be distinguishable
with LHC+ILC data. The most important observables are determined to be the
(left) smuon and selectron masses and the splitting between them, respectively.
Splitting in the (left) smuon and selectrons is tiny in most of cMSSM parameter
space, but can be quite sizeable for large values of the seesaw scale,
. Thus, for very roughly GeV hints for type-I
seesaw might appear in SUSY mass measurements. Since our numerical results
depend sensitively on forecasted error bars, we discuss in some detail the
accuracies, which need to be achieved, before a realistic analysis searching
for signs of type-I seesaw in SUSY spectra can be carried out.Comment: 17 pages, 7 figure
Enhancing studentsβ motivation to learn software engineering programming techniques: a collaborative and social interaction approach
To motivate students to study advanced programming techniques, including the use of architectural styles such as the modelβviewβcontroller pattern, we have con-ducted action research upon a project based-learning approach. In addition to collabo-ration, the approach includes studentsβ searching and analysis of scientific documents and their involvement in communities of practice outside academia. In this paper, we report the findings of second action research cycle, which took place throughout the fourth semester of a six-semester program. As with the previous cycle during the pre-vious academic year, students did not satisfactorily achieve expected learning out-comes. More groups completed the assigned activities, but results continue to reflect poor engagement in the communities of practice and very low performance in other learning tasks. From the collected data we have identified new approaches and recom-mendations for subsequent research.Fundação para a CiΓͺncia e Tecnologia (FCT), Portugal, for Ph.D. Grants SFRH/BD/91309/2012 and SFRH/BD/87815/201
Beyond the standard seesaw: neutrino masses from Kahler operators and broken supersymmetry
We investigate supersymmetric scenarios in which neutrino masses are
generated by effective d=6 operators in the Kahler potential, rather than by
the standard d=5 superpotential operator. First, we discuss some general
features of such effective operators, also including SUSY-breaking insertions,
and compute the relevant renormalization group equations. Contributions to
neutrino masses arise at low energy both at the tree level and through finite
threshold corrections. In the second part we present simple explicit
realizations in which those Kahler operators arise by integrating out heavy
SU(2)_W triplets, as in the type II seesaw. Distinct scenarios emerge,
depending on the mechanism and the scale of SUSY-breaking mediation. In
particular, we propose an appealing and economical picture in which the heavy
seesaw mediators are also messengers of SUSY breaking. In this case, strong
correlations exist among neutrino parameters, sparticle and Higgs masses, as
well as lepton flavour violating processes. Hence, this scenario can be tested
at high-energy colliders, such as the LHC, and at lower energy experiments that
measure neutrino parameters or search for rare lepton decays.Comment: LaTeX, 34 pages; some corrections in Section
Constrained SUSY seesaws with a 125 GeV Higgs
Motivated by the ATLAS and CMS discovery of a Higgs-like boson with a mass
around 125 GeV, and by the need of explaining neutrino masses, we analyse the
three canonical SUSY versions of the seesaw mechanism (type I, II and III) with
CMSSM boundary conditions. In type II and III cases, SUSY particles are lighter
than in the CMSSM (or the constrained type I seesaw), for the same set of input
parameters at the universality scale. Thus, to explain
at low energies, one is forced into regions of parameter space with very large
values of , or . We compare the squark and gluino masses
allowed by the ATLAS and CMS ranges for (extracted from the 2011-2012
data), and discuss the possibility of distinguishing seesaw models in view of
future results on SUSY searches. In particular, we briefly comment on the
discovery potential of LHC upgrades, for squark/gluino mass ranges required by
present Higgs mass constraints. A discrimination between different seesaw
models cannot rely on the Higgs mass data alone, therefore we also take into
account the MEG upper limit on BR and show that, in some
cases, this may help to restrict the SUSY parameter space, as well as to set
complementary limits on the seesaw scale.Comment: 28 pages, 7 figures. v2: comments and references added. Final version
to appear in JHE
The implications of three major new trials for the effect of water, sanitation and hygiene on childhood diarrhea and stunting: a consensus statement
BACKGROUND: Three large new trials of unprecedented scale and cost, which included novel factorial designs, have found no effect of basic water, sanitation and hygiene (WASH) interventions on childhood stunting, and only mixed effects on childhood diarrhea. Arriving at the inception of the United Nations' Sustainable Development Goals, and the bold new target of safely managed water, sanitation and hygiene for all by 2030, these results warrant the attention of researchers, policy-makers and practitioners. MAIN BODY: Here we report the conclusions of an expert meeting convened by the World Health Organization and the Bill and Melinda Gates Foundation to discuss these findings, and present five key consensus messages as a basis for wider discussion and debate in the WASH and nutrition sectors. We judge these trials to have high internal validity, constituting good evidence that these specific interventions had no effect on childhood linear growth, and mixed effects on childhood diarrhea. These results suggest that, in settings such as these, more comprehensive or ambitious WASH interventions may be needed to achieve a major impact on child health. CONCLUSION: These results are important because such basic interventions are often deployed in low-income rural settings with the expectation of improving child health, although this is rarely the sole justification. Our view is that these three new trials do not show that WASH in general cannot influence child linear growth, but they do demonstrate that these specific interventions had no influence in settings where stunting remains an important public health challenge. We support a call for transformative WASH, in so much as it encapsulates the guiding principle that - in any context - a comprehensive package of WASH interventions is needed that is tailored to address the local exposure landscape and enteric disease burden
The subchondral bone in articular cartilage repair: current problems in the surgical management
As the understanding of interactions between articular cartilage and subchondral bone continues to evolve, increased attention is being directed at treatment options for the entire osteochondral unit, rather than focusing on the articular surface only. It is becoming apparent that without support from an intact subchondral bed, any treatment of the surface chondral lesion is likely to fail. This article reviews issues affecting the entire osteochondral unit, such as subchondral changes after marrow-stimulation techniques and meniscectomy or large osteochondral defects created by prosthetic resurfacing techniques. Also discussed are surgical techniques designed to address these issues, including the use of osteochondral allografts, autologous bone grafting, next generation cell-based implants, as well as strategies after failed subchondral repair and problems specific to the ankle joint. Lastly, since this area remains in constant evolution, the requirements for prospective studies needed to evaluate these emerging technologies will be reviewed
Activity-Induced Remodeling of Olfactory Bulb Microcircuits Revealed by Monosynaptic Tracing
The continued addition of new neurons to mature olfactory circuits represents a remarkable mode of cellular and structural brain plasticity. However, the anatomical configuration of newly established circuits, the types and numbers of neurons that form new synaptic connections, and the effect of sensory experience on synaptic connectivity in the olfactory bulb remain poorly understood. Using in vivo electroporation and monosynaptic tracing, we show that postnatal-born granule cells form synaptic connections with centrifugal inputs and mitral/tufted cells in the mouse olfactory bulb. In addition, newly born granule cells receive extensive input from local inhibitory short axon cells, a poorly understood cell population. The connectivity of short axon cells shows clustered organization, and their synaptic input onto newborn granule cells dramatically and selectively expands with odor stimulation. Our findings suggest that sensory experience promotes the synaptic integration of new neurons into cell type-specific olfactory circuits
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