1,058 research outputs found
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
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
Knowledge representation for culturally competent personal robots: requirements, design principles, implementation, and assessment
Culture, intended as the set of beliefs, values, ideas, language, norms and customs which compose a person’s life, is an essential element to know by any robot for personal assistance. Culture, intended as that person’s background, can be an invaluable source of information to drive and speed up the process of discovering and adapting to the person’s habits, preferences and needs. This article discusses the requirements posed by cultural competence on the knowledge management system of a robot. We propose a framework for cultural knowledge representation that relies on (i) a three layer ontology for storing concepts of relevance, culture specific information and statistics, person-specific information and preferences; (ii) an algorithm for the acquisition of person-specific knowledge, which uses culture specific knowledge to drive the search; (iii) a Bayesian Network for speeding up the adaptation to the person by propagating the effects of acquiring one specific information onto interconnected concepts. We have conducted a preliminary evaluation of the framework involving 159 Italian and German volunteers and considering 122 among habits, attitudes and social norms
Interplay of LFV and slepton mass splittings at the LHC as a probe of the SUSY seesaw
We study the impact of a type-I SUSY seesaw concerning lepton flavour
violation (LFV) both at low-energies and at the LHC. The study of the di-lepton
invariant mass distribution at the LHC allows to reconstruct some of the masses
of the different sparticles involved in a decay chain. In particular, the
combination with other observables renders feasible the reconstruction of the
masses of the intermediate sleptons involved in decays. Slepton mass splittings can be either
interpreted as a signal of non-universality in the SUSY soft breaking-terms
(signalling a deviation from constrained scenarios as the cMSSM) or as being
due to the violation of lepton flavour. In the latter case, in addition to
these high-energy processes, one expects further low-energy manifestations of
LFV such as radiative and three-body lepton decays. Under the assumption of a
type-I seesaw as the source of neutrino masses and mixings, all these LFV
observables are related. Working in the framework of the cMSSM extended by
three right-handed neutrino superfields, we conduct a systematic analysis
addressing the simultaneous implications of the SUSY seesaw for both high- and
low-energy lepton flavour violation. We discuss how the confrontation of
slepton mass splittings as observed at the LHC and low-energy LFV observables
may provide important information about the underlying mechanism of LFV.Comment: 50 pages, 42 eps Figures, typos correcte
Proton MR spectroscopy of the foramen of Monro region in patients with tuberous sclerosis complex
Doppler and birth weight Z score: predictors for adverse neonatal outcome in severe fetal compromise
BACKGROUND: An adequate placental perfusion is crucial for the normal growth and well being of the fetus and newborn. The blood flow through the placenta can be compromised in a variety of clinical situations, always causing important damage to the gestation. Our objective is to identify significant predictors for adverse neonatal outcome in severe fetal compromise. METHODS: Consecutive premature fetuses at between 25 and 32 weeks with severe placental insufficiency were examined prospectively. Inclusion criteria were: (i) singletons (ii) normal anatomy; (iii) abnormal umbilical artery Doppler pulsatility index (PI); (iv) abnormal cerebroplacental ratio; (v) middle cerebral artery (MCA) PI < - 2SD ("brain sparing"); (vi) last Doppler examination performed within 24 hours prior to delivery. All 46 patients that met criteria and started the study were followed to the end. We considered as independent potential predicting variables: absent or reversed end diastolic flow in umbilical artery, abnormal ductus venosus S/A ratio, absent or reversed flow during atrial contraction in the ductus venosus and birth weight Z score. Outcome parameters were: neonatal mortality and severe neonatal morbidity. RESULTS: Backward stepwise logistic regression analysis was used to determine the optimal model for the prediction of neonatal mortality and severe neonatal morbidity. In this analysis birth weight Z score index showed the strongest association OR = 1,87 [1,17-2,99] with all neonatal outcome, all other independent variables were excluded for the optimal model. There was no mortality for the group with normal birth weight Z score. CONCLUSION: Our study suggests that birth weight Z score is the strongest predictor of adverse neonatal outcome in severe placental insufficiencies. Such use of Z scores, allowing to get rid of gestational age or sex covariates could be extended to estimated fetal weight and might help in making important decisions in the management of compromised pregnancies
Intraspecific crosses resulting in the first occurrence of eight and nine B chromosomes in Prochilodus lineatus (Characiformes, Prochilodontidae)
B chromosomes are supernumerary elements present in about 15% of eukaryotic species and are most frequently heterochromatic, behave parasitically, show a transmission rate higher than standard (A) chromosomes, and can provoke harmful effects on carriers. In the current work, Prochilodus lineatus individuals carrying eight and nine B chromosomes were obtained by induced crossing performed involving breeders with different B chromosome numbers in their cells. The high B chromosome numbers found in the offspring were recorded for the first time in this species. The use of cytogenetic techniques applied in the present study revealed that regardless of the increase in number of B chromosomes in the genome of these individuals, those elements did not presented active genes, and showed their normal heterochromatic characteristic
Associação do reflexo vermelho em recém-nascidos com variáveis neonatais
Objetivou-se investigar o resultado do teste do reflexo vermelho, conhecido como teste do olhinho, e associar as impressões do reflexo com variáveis neonatais. Este é um estudo descritivo, quantitativo, realizado com 190 recém-nascidos de uma maternidade pública, dos quais 187 apresentaram resultado não alterado e três suspeitos. Observaram-se diferentes nuances de coloração do reflexo: em 50 (26,3%) a coloração do reflexo apresentou-se vermelha; 34 (17,9%) laranja-avermelhado; 92 (48,4%) alaranjado; 11 (5,8%) amarelo claro e três (1,6%) com manchas esbranquiçadas. Encontraram-se associações estatisticamente significantes entre o instrumento gradiente de cores e variáveis neonatais: peso (p=0,03), idade gestacional (p=0,019) e oxigenoterapia (p=0,024). Enfermeiros capacitados para prática e avaliação desse teste podem se tornar profissionais em potencial para a prevenção da cegueira infantil.The aim of this study was to investigate the results of the red reflex test and to associate these results with neonatal variables. This descriptive study was conducted with 190 newborns in a public maternity hospital. A total of 187 infants presented no alteration and three presented suspect results. Different shades of reflex color were observed: 50 (26.3%) presented red; 34 (17.9%) orange-red, 92 (48.4%) orange, 11 (5.8%) light yellow and three (1.6%) milky white spots. Statistically significant associations between the color gradient instrument and neonatal variables were found: weight (p=0.03), gestational age (p=0.019) and oxygen therapy (p=0.024). Nurses trained to practice and evaluate this test may become professionals in the potential for the prevention of childhood blindness.Se objetivó investigar el resultado de la prueba del reflejo rojo, conocido como prueba del ojito, y asociar las impresiones del reflejo con variables neonatales. Se trata de un estudio descriptivo, cuantitativo, realizado con 190 recién nacidos de una maternidad pública; de los cuales 187 presentaron resultados no alterados y tres sospechosos. Se observaron diferentes matices de coloración del reflejo: en 50 (26,3%) se presentó rojo; 34 (17,9%) naranja rojizo; 92 (48,4%) anaranjado; 11 (5,8%) amarillo claro y tres (1,6%) con manchas blanquecinas. Se encontraron asociaciones estadísticamente significativas entre el instrumento gradiente de colores y las variables neonatales: peso (p=0,03), edad de gestación (p=0,019) y oxigenoterapia (p=0,024). Enfermeros capacitados para la práctica y evaluación de esa prueba pueden tornarse profesionales en potencial para la prevención de la ceguera infantil
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