Generalized CP Invariance and the Yukawa sector of Two-Higgs Models

We analyze generalized CP symmetries of two-Higgs doublet models, extending them from the scalar to the fermion sector of the theory. We show that, with a single exception, those symmetries imply massless fermions. The single model which accommodates a fermionic mass spectrum compatible with experimental data possesses a remarkable feature. It displays a new type of spontaneous CP violation, which occurs not in the scalar sector responsible for the symmetry breaking mechanism but, rather, in the fermion sector.Comment: RevTex, 4 pages, no figures Version2: Remarkable additional conclusion => title & text changes; section adde

Evidence for non-Gaussianity in the COBE DMR Four Year Sky Maps

We introduce and study the distribution of an estimator for the normalized bispectrum of the Cosmic Microwave Background (CMB) anisotropy. We use it to construct a goodness of fit statistic to test the coadded 53 and 90 GHz COBE-DMR 4 year maps for non-Gaussianity. Our results indicate that Gaussianity is ruled out at the confidence level in excess of 98%. This value is a lower bound, given all the investigated systematics. The dominant non-Gaussian contribution is found near the multipole of order $\ell=16$. Our attempts to explain this effect as caused by the diffuse foreground emission from the Galaxy have failed. We conclude that unless there exists a microwave foreground emission which spatially correlates neither with the DIRBE nor Haslam maps, the cosmological CMB anisotropy is genuinely non-Gaussian.Comment: 16 pages, 3 figs uses aasms4.tex, revised and accepted to Ap. J. Let

Where is the COBE maps' non-Gaussianity?

We review our recent claim that there is evidence of non-Gaussianity in the 4 Year COBE DMR data. We present some new results concerning the effect of the galactic cut upon the non-Gaussian signal. These findings imply a localization of the non-Gaussian signal on the Northern galactic hemisphere.Comment: Proceedings of COSMO98 Asiloma

Implications of the LHC two-photon signal for two-Higgs-doublet models

We study the implications for Two Higgs Doublet Models of the recent announcement at the LHC giving a tantalizing hint for a Higgs boson of mass 125 GeV decaying into two photons. We require that the experimental result be within a factor of two of the theoretical Standard Model prediction, and analyze the type I and type II models as well as the lepton-specific and flipped models, subject to this requirement. It is assumed that there is no new physics other than two Higgs doublets. In all of the models, we display the allowed region of parameter space taking the recent LHC announcement at face value, and we analyze the $W^+W^-$, $ZZ$, $\bar{b}b$ and $\tau^+\tau^-$ expectations in these allowed regions. Throughout the entire range of parameter space allowed by the $\gamma\gamma$ constraint, the number of events for Higgs decays into $WW$, $ZZ$ and $b \bar b$ are not changed from the Standard Model by more than a factor of two. In contrast, in the Lepton Specific model, decays to $\tau^+ \tau^-$ are very sensitive across the entire $\gamma \gamma$-allowed region.Comment: Latex, 6 pages, 4 figures; v2 - added 2 reference

Mass-degenerate Higgs bosons at 125 GeV in the Two-Higgs-Doublet Model

The analysis of the Higgs boson data by the ATLAS and CMS Collaborations appears to exhibit an excess of h --> gamma\gamma events above the Standard Model (SM) expectations; whereas no significant excess is observed in h --> ZZ* --> {four lepton} events, albeit with large statistical uncertainty due to the small data sample. These results (assuming they persist with further data) could be explained by a pair of nearly mass-degenerate scalars, one of which is a SM-like Higgs boson and the other is a scalar with suppressed couplings to W+W- and ZZ. In the two Higgs doublet model, the observed \gamma\gamma and ZZ* --> {four lepton} data can be reproduced by an approximately degenerate CP-even (h) and CP-odd (A) Higgs boson for values of \sin(\beta-\alpha) near unity and 0.7 < \tan\beta < 1. An enhanced \gamma\gamma signal can also arise in cases where m_h ~ m_H, m_H ~ m_A, or m_h ~ m_H ~ m_A. Since the ZZ* --> {four lepton} signal derives primarily from a SM-like Higgs boson whereas the \gamma\gamma signal receives contributions from two (or more) nearly mass-degenerate states, one would expect a slightly different invariant mass peak in the ZZ* --> {four lepton} and \gamma\gamma channels. The phenomenological consequences of such models can be tested with additional Higgs data that will be collected at the LHC in the near future.Comment: 18 pages, 19 pdf figures, v2: references added, v3&v4: added refs and explanation

Team-Based Learning in Chemistry Courses with Laboratory Sessions

[EN] The implementation of Team-Based Learning (TBL, http://www.teambasedlearning.org) in one-semester undergraduate courses of chemistry offered to first year students is reported. TBL is an active learning instructional strategy heavily relying on small group interaction. Teaching lab classes in a TBL context presented a specific challenge, as decisions were required about their role in the global framework and the possibility of incorporating lab activities as “teamwork”. The design of lab sessions as TBL team application activities is here also illustrated, both for a course of General Chemistry and a course of Organic Chemistry. TBL dramatically improved students class attendance and participation. Its implementation has provided a unique opportunity for the pedagogical development of teaching staff. A moderate number of students reported discomfort with TBL: the requirement of individual preparation before classes and the impact of team participation in the final grade is indeed a new ground for most students, often perceived as a troubling deviation from the common social paradigm of the learning process. The role of the instructor as a facilitator of individual and team work, and the clear explanation of the method are thus of utmost relevance.The authors thank Faculdade de Ciências e Tecnologia (Universidade Nova de Lisboa) for financial supportAires-De-Sousa, J.; Cardoso, MM.; Ferreira, L.; Lima, J.; Noronha, J.; Nunes, A.; Ponte, M. (2017). Team-Based Learning in Chemistry Courses with Laboratory Sessions. En Proceedings of the 3rd International Conference on Higher Education Advances. Editorial Universitat Politècnica de València. 1213-1218. https://doi.org/10.4995/HEAD17.2017.5559OCS1213121

Concise Review: Salivary Gland Regeneration: Therapeutic Approaches from Stem Cells to Tissue Organoids

The human salivary gland (SG) has an elegant architecture of epithelial acini, connecting ductal branching structures, vascular and neuronal networks that together function to produce and secrete saliva. This review focuses on the translation of cell‐ and tissue‐based research toward therapies for patients suffering from SG hypofunction and related dry mouth syndrome (xerostomia), as a consequence of radiation therapy or systemic disease. We will broadly review the recent literature and discuss the clinical prospects of stem/progenitor cell and tissue‐based therapies for SG repair and/or regeneration. Thus far, several strategies have been proposed for the purpose of restoring SG function: (1) transplanting autologous SG‐derived epithelial stem/progenitor cells; (2) exploiting non‐epithelial cells and/or their bioactive lysates; and (3) tissue engineering approaches using 3D (three‐dimensional) biomaterials loaded with SG cells and/or bioactive cues to mimic in vivo SGs. We predict that further scientific improvement in each of these areas will translate to effective therapies toward the repair of damaged glands and the development of miniature SG organoids for the fundamental restoration of saliva secretion. Stem Cells 2017;35:97–105Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/135510/1/stem2455.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/135510/2/stem2455_am.pd

Adapting and adopting River Habitat Survey : problems and solutions for fluvial hydromorphological assessment in Portugal

The Water Framework Directive (WFD), which established the use of hydromorphological quality elements to assess the ecological status of water bodies, has influenced the purpose and content of several European methods for characterizing physical structure and assessing habitat quality in rivers. The River Habitat Survey (RHS) is a WFD compliant method developed in the UK and follows rapid and simple survey procedures using a standardised approach to characterize the physical habitat and evaluate hydromorphological quality. In Portugal, RHS was adopted for WFD purposes due to its successful long term application across the UK and other European countries. Even so, an effort was made to adapt the RHS to Portuguese regional and river characteristics, in order to accurately record habitat features, assess habitat quality and comply with legal requirements. This paper describes the constraints, adaptations, state of the art and way forward for a successful RHS implementation in Portugal. Constraints concerning the application of RHS to Mediterranean rivers are strongly related to natural hydromorphological processes, namely annual and inter-annual flow variability, which is a potential source of covariance with anthropogenic pressures. This leads to difficulties in recognizing and accurately recording some RHS features. Adaptations to RHS were introduced for survey guidelines, recording procedures and improved definitions of habitat features. Additional modifications were prepared in different sections of RHS field form to reflect Portuguese river features and incorporate components required by the WFD.La Directiva Marco del Agua (DMA), que estableció el uso de indicadores de calidad hidromorfológicos para evaluar el estado ecológico de las masas de agua, ha influido en la finalidad y el contenido de varios métodos europeos para la caracterización de la estructura física y la evaluación de la calidad del h'abitat en los ríos. El River Habitat Survey (RHS) es un método compatible con la DMA desarrollado en el Reino Unido y sigue los procedimientos de encuesta rápida y sencilla utilizando un método estándar para caracterizar el hábitat físico y evaluar la calidad hidromorfológa. En Portugal, el RHS fue adoptado a efectos de la DMA debido a su exitosa aplicación a largo plazo en el Reino Unido y otros países europeos. Aun así, se hizo un esfuerzo para adaptar el RHS a las características regionales y de los ríos de Portugal, con el fin de registrar con precisión las características del hábitat, evaluar la calidad del hábitat y cumplir con los requisitos legales. Este artículo describe las limitaciones, las adaptaciones, el estado de implementacion y la manera para una implementación exitosa de RHS en Portugal. Las restricciones relativas a la aplicación de RHS a los ríos del Mediterráneo están fuertemente relacionadas con procesos hidromorfológicos naturales, como es la variabilidad del flujo anual e interanual, la cual es una fuente potencial de covarianza con presiones antropogénicas. Esto lleva a dificultades para reconocer y registrar con precisión algunas de las caracter'ısticas del RHS. Se han introducido adaptaciones al RHS en las directrices de muestreo, en los procedimientos de registro y se han mejorado algunas definiciones de ciertas características del hábitat. Otras modificaciones adicionales se han realizado en diferentes secciones del formulario de campo del RHS para reflejar las características de los ríos por tugueses y ciertas componentes requeridas por la DMA

Strecker degradation of amino acids promoted by a camphor-derived sulfonamide

A camphor-derived sulfonimine with a conjugated carbonyl group, oxoimine 1 (O2SNC10H13O), reacts with amino acids (glycine, L-alanine, L-phenylalanine, L-leucine) to form a compound O2SNC10H13NC10H14NSO2 (2) which was characterized by spectroscopic means (MS and NMR) and supported by DFT calculations. The product, a single diastereoisomer, contains two oxoimine units connected by a –N= bridge, and thus has a structural analogy to the colored product Ruhemann´s purple obtained by the ninhydrin reaction with amino acids. A plausible reaction mechanism that involves zwitterions, a Strecker degradation of an intermediate imine and water-catalyzed tautomerizations was developed by means of DFT calculations on potential transition states