A Rationale for Long-lived Quarks and Leptons at the LHC: Low Energy Flavour Theory

In the framework of gauged flavour symmetries, new fermions in parity symmetric representations of the standard model are generically needed for the compensation of mixed anomalies. The key point is that their masses are also protected by flavour symmetries and some of them are expected to lie way below the flavour symmetry breaking scale(s), which has to occur many orders of magnitude above the electroweak scale to be compatible with the available data from flavour changing neutral currents and CP violation experiments. We argue that, actually, some of these fermions would plausibly get masses within the LHC range. If they are taken to be heavy quarks and leptons, in (bi)-fundamental representations of the standard model symmetries, their mixings with the light ones are strongly constrained to be very small by electroweak precision data. The alternative chosen here is to exactly forbid such mixings by breaking of flavour symmetries into an exact discrete symmetry, the so-called proton-hexality, primarily suggested to avoid proton decay. As a consequence of the large value needed for the flavour breaking scale, those heavy particles are long-lived and rather appropriate for the current and future searches at the LHC for quasi-stable hadrons and leptons. In fact, the LHC experiments have already started to look for them.Comment: 10 pages, 1 figur

Quark flavour conserving violations of the lepton number

We study supersymmetric models of lepton and baryon number violation based on an abelian family gauge group. Due to possible lepton-Higgs mixing, the lepton violating couplings are related to the Yukawa couplings and may be generated by them even if they were absent in the original theory. Such terms may be dominant and are not given by the naive family charge counting rules. This enhancement mechanism can provide an alignment between lepton-number violating terms and Yukawa couplings: as a result they conserve quark flavour. A natural way of suppressing baryon number violation in this class of models is also proposed

Extraction of the x-dependence of the non-perturbative QCD b-quark fragmentation distribution component

Using recent measurements of the b-quark fragmentation distribution obtained in $e^+e^- \to b \bar{b}$ events registered at the Z pole, the non-perturbative QCD component of the distribution has been extracted independently of any hadronic physics modelling. This distribution depends only on the way the perturbative QCD component has been defined. When the perturbative QCD component is taken from a parton shower Monte-Carlo, the non-perturbative QCD component is rather similar with those obtained from the Lund or Bowler models. When the perturbative QCD component is the result of an analytic NLL computation, the non-perturbative QCD component has to be extended in a non-physical region and thus cannot be described by any hadronic modelling. In the two examples used to characterize these two situations, which are studied at present, it happens that the extracted non-perturbative QCD distribution has the same shape, being simply translated to higher-x values in the second approach, illustrating the ability of the analytic perturbative QCD approach to account for softer gluon radiation than with a parton shower generator.Comment: 13 page

Systematic Heuristic Evaluation of Computerized Consultation Order Templates: Clinicians’ and Human Factors Engineers’ Perspectives

We assessed the usability of consultation order templates and identified problems to prioritize in design efforts for improving referral communication. With a sample of 26 consultation order templates, three evaluators performed a usability heuristic evaluation. The evaluation used 14 domain-independent heuristics and the following three supplemental references: 1 new domain-specific heuristic, 6 usability goals, and coded clinicians’ statements regarding ease of use for 10 sampled templates. Evaluators found 201 violations, a mean of 7.7 violations per template. Minor violations outnumbered major violations almost twofold, 115 (57%) to 62 (31%). Approximately 68% of violations were linked to 5 heuristics: aesthetic and minimalist design (17%), error prevention (16%), consistency and standards (14%), recognition rather than recall (11%), and meet referrers’ information needs (10%). Severe violations were attributed mostly to meet referrers’ information needs and recognition rather than recall. Recorded violations yielded potential negative consequences for efficiency, effectiveness, safety, learnability, and utility. Evaluators and clinicians demonstrated 80% agreement in usability assessment. Based on frequency and severity of usability heuristic violations, the consultation order templates reviewed may impede clinical efficiency and risk patient safety. Results support the following design considerations: communicate consultants’ requirements, facilitate information seeking, and support communication. While the most frequent heuristic violations involved interaction design and presentation, the most severe violations lacked information desired by referring clinicians. Violations related to templates’ inability to support referring clinicians’ information needs had the greatest potential negative impact on efficiency and safety usability goals. Heuristics should be prioritized in future design efforts

Identidades, colonialismo e ensino de filosofia

Monografia (graduação)—Universidade de Brasília, Instituto de Ciências Humanas, Departamento de Filosofia, 2015.Uma discussão importante que deve ser levada em consideração quando pensamos sobre os conteúdos utilizados nas aulas ministradas de filosofia é se esses possuem uma compatibilidade com as vivências particulares e coletivas daquelas crianças e jovens que estão acolhendo esse ensinamento. A escola é uma das portas de entrada das cidadãs e cidadãos no mundo social, influenciando drasticamente no comportamento a ser exercido por estes. Por vezes, acabamos por caminhar pelo mesmo discurso do dominador, onde a diversidade e pluralidade acabam por serem suprimidas, vangloriando o discurso eurocêntrico em detrimento de outras doutrinas filosóficas que não estão compatibilizadas por essa sistematização europeia. Cabe a reflexão acerca das escolhas que a educadora e o educador irão fazer para contemplar e trabalhar com mais uma disciplina que irá auxiliar na construção das identidades de seus estudantes. É com este intuito que cabe a avaliação dos livros didáticos que são escolhidos pela escola, ou pela/pelo própria/próprio profissional que irá lecionar as aulas, visto que esses por vezes são a única ponte de comunicação entre a/o educadora/educador e a/o estudante. Nesse sentido, a construção desse trabalho levanta algumas questões sobre o material didático e o papel dos profissionais utilizando o material, problematizando o que nos foi imposto até aqui, apenas a utilização da filosofia europeia. ___________________________________________________________________________ ABSTRACTAn important discussion that should be taken in account when it comes to the contents teached in philosophy classes is if they are compatible with the individual and collective experiences of the students who are absorbing these teachings. Schools are one of the gateways for citizens into the social world, causing a drastic influence on the behavior engaged by them. Sometimes we end up preaching the Eurocentric thinking, in which diversity and plurality end up being suppressed, boasting the Eurocentric discourse over other philosophical doctrines that are not compatible with the European model. It is worth reflecting on the choices that teachers will make to analyze and work with another subject that will assist in the construction of their student’s identities. That is why the schoolbooks chosen by schools or by the professionals who will teach the classes should be evaluated, since, many times, the books are the only bridge of communication between teachers and students. In this sense, this work raises questions concerning the teaching materials and the role of professionals who use them, discussing what has been imposed upon us so far, which is the European philosophy

Reaction mechanism of trypsin-catalysed semisynthesis of human insulin studied by fast atom bombardment mass spectrometry

The production of semisynthetic human insulin for therapeutic purposes is of considerable importance. During trypsin-catalysed transformation of pig insulin into an ester of insulin of human sequence, the alanyl residue at position B30 is removed and replaced with an esterified residue of threonine. We have carried out this transformation in a medium enriched in 18OH2 and studied the product by MS. In contrast to a previous report, we find that incorporation of label into the B29−B30 peptide bond occurs during the transformation with threonine methyl ester in aqueous N, N-dimethylacetamide. Quantitative data are presented and the implications of these findings are discusse

Report of the GDR working group on the R-parity violation

This report summarizes the work of the "R-parity violation group" of the French Research Network (GDR) in Supersymmetry, concerning the physics of supersymmetric models without conservation of R-parity at HERA, LEP, Tevatron and LHC and limits on R-parity violating couplings from various processes. The report includes a discussion of the recent searches at the HERA experiment, prospects for new experiments, a review of the existing limits, and also theoretically motivated alternatives to R-parity and a brief discussion on the implications of R-parity violation on the neutrino masses.Comment: 60 pages, LaTeX, 22 figures, 2 table

Emergent productivity regimes of river networks

High-resolution data are improving our ability to resolve temporal patterns and controls on river productivity, but we still know little about the emergent patterns of primary production at river-network scales. Here, we estimate daily and annual river-network gross primary production (GPP) by applying characteristic temporal patterns of GPP (i.e., regimes) representing distinct river functional types to simulated river networks. A defined envelope of possible productivity regimes emerges at the network-scale, but the amount and timing of network GPP can vary widely within this range depending on watershed size, productivity in larger rivers, and reach-scale variation in light within headwater streams. Larger rivers become more influential on network-scale GPP as watershed size increases, but small streams with relatively low productivity disproportionately influence network GPP due to their large collective surface area. Our initial predictions of network-scale productivity provide mechanistic understanding of the factors that shape aquatic ecosystem function at broad scales

Abelian Flavour Symmetries in Supersymmetric Models

We propose a theory of flavour based on abelian horizontal gauge symmetries and modular invariances. We construct explicit supergravity models where the scale of the horizontal $U(1)$ symmetry breaking is fixed by the Green-Schwarz mechanism for anomaly cancellation. The supersymmetric spectrum is obtained in terms of the $U(1)$ charges which are determined by the Yukawa matrices.Comment: 30 pages, LaTeX, no figure