FCNC decays of SM fermions into a dark photon

We analyze a new class of FCNC processes, the $f \to f^{\prime} \, \bar{\gamma}$ decays of a fermion $f$ into a lighter (same-charge) fermion $f^{\prime}$ plus a {\it massless} neutral vector boson, a {\it dark photon} $\bar{\gamma}$. A massless dark photon does not interact at tree level with observable fields, and the $f \!\to\! f^{\prime} \, \bar{\gamma}$ decay presents a characteristic signature where the final fermion $f^{\prime}$ is balanced by a {\it massless invisible} system. Models recently proposed to explain the exponential spread in the standard-model Yukawa couplings can indeed foresee an extra unbroken {\it dark} $U(1)$ gauge group, and the possibility to couple on-shell dark photons to standard-model fermions via one-loop magnetic-dipole kind of FCNC interactions. The latter are suppressed by the characteristic scale related to the mass of heavy messengers, connecting the standard model particles to the dark sector. We compute the corresponding decay rates for the top, bottom, and charm decays ($t\to c\, \bar{\gamma},u\, \bar{\gamma}$, $\;b\to s\, \bar{\gamma},d\, \bar{\gamma}$, and $c\to u \bar{\gamma}$), and for the charged-lepton decays ($\tau \to \mu\, \bar{\gamma}, e\, \bar{\gamma}$, and $\mu \to e \bar{\gamma}$) in terms of model parameters. We find that large branching ratios for both quark and lepton decays are allowed in case the messenger masses are in the discovery range of the LHC. Implications of these new decay channels at present and future collider experiments are briefly discussed.Comment: 44 pages, 9 figures, BBbar constraints and new references included, same version as the published on

INNOVATIVE MASS-DAMPING-BASED APPROACHES FOR SEISMIC DESIGN OF TALL BUILDINGS

Mass damping is a well known principle for the reduction of structural vibrations and applied in tall building design in a variety of configurations. With mass usually small (around 1% of building mass), the properly “tuned” mass damper (TMD) shows great effectiveness in reduc-ing wind vibrations, but minor advantages under earthquake excitations. The above limitation can be surpassed by utilizing relatively large mass TMD. For this pur-pose, two different solutions are here proposed. In both cases, the idea is to separate the building into two or more parts, thus allowing for a relative motion between them, and acti-vating the mass damping mechanism. In the first solution, the building is subdivided along elevation into an upper and a lower structure, separated by means of an intermediate isolation system (IIS). In the second solution, by revisiting the classical mega-frame typology, the exterior full-height structure provides the global strength and stiffness, and secondary structures, extending between two transfer levels, are physically detached from the main structure at each floor and isolated at transfer level. Simplified lumped-mass models are developed for illustrating the dynamic behaviour of the two solutions and carrying out parametric analyses. Procedures for deriving optimum values of design parameters are also proposed and compared to the parametric study

I Residui del trattamento di potabillizzazione delle acque come adsorbenti dell'arsenico in suoli contaminati

In this study we determined, at different pH values (pH 4, 7 and 9), the ability of a Fe- and an Al-based water treatment residues (WTRs) to accumulate As(V) from an aqueous solution and to define the mechanisms which regulate the sorption of this anion. The Fe-WTR showed a greater As(V) sorption capacity with respect to Al-WTR at all the pH values studied [e.g. 1.65 mmol•g-1 and 1.02 mmol•g-1 of As(V) sorbed at pH 4 respectively]. Sequential extraction of As(V)-WTR suggests that the main mechanism governing the sorption of As(V) likely involved the formation of inner-sphere surface complexes [Fe/Al–O–As]. The capacity of Fe- and Al-WTR to decrease the mobility and bioaccessibility of As in a polluted sub-acidic soil (~2267 mg•kg-1 d.m.) was also evaluated. The addition of both sorbents at two application rates (1 and 2% w/w) induced a shift of the labile As fractions towards different ones more strongly retained by the components of WTRs (particularly by the Fe/Al amorphous (hydr)oxides), with the consequent decrease of the As mobility. All the treatments favoured a decrease (even if not significantly) of As bioaccessibility, evaluated through the SBET (stomach phase extraction at pH 1.5) and the SBRCG (intestinal phase extraction at pH 7.0) analyses, which simulate the gastrointestinal processes. The results presented show that both WTRs can be useful at decreasing the mobility and bioaccessibility of As, so favouring a certain recovery of the functionality of polluted soil

Implantes Pterigóides: solução alternativa de reabilitação da maxila severamente atrófica

Substituir os dentes perdidos na maxila posterior é sempre um desafio para o Médico Implantologista, pois a maxila posterior apresenta numerosos obstáculos na forma de qualidade, quantidade, anatomia do seio maxilar e inacessibilidade. Para superar essas deficiências, vários procedimentos cirúrgicos, como aumento do seio, aumento do osso, implantes inclinados, implantes curtos, implantes pterigoides e implantes zigomáticos foram testados. A região pterigomaxillar fornece uma excelente área para colocação de implantes. Objectivo: Realizar uma análise detalhada sobre a alternativa cirúrgica de posicionamento dos implantes pterigóides. Partindo dos aspetos anatômicos fundamentais, que esta técnica exige conhecer, as condições em que o uso deste procedimento é indicado, até a explicação das características deste implante, o procedimento cirúrgico com o protocolo específico, enfatizando as vantagens e desvantagens desta abordagem. Materiais e métodos: extensa recolha bibliográfica, tendo sido efetuada uma pesquisa em livros, teses de mestrado e em revistas científicas na área da medicina. Procedeu-se a uma busca nas bases de dados bibliográficos em motores de pesquisa on-line da PubMed. Reuniram-se 62 artigos publicados entre os anos 1987 e 2017. Após a sua leitura e análise foram considerados 32 artigos que na nossa opinião apresentavam metodologia científica adequada para as conclusões neles enunciadas. Discussão: O implante pterigoide é uma alternativa para o grande aumento do seio maxilar e tem um comprimento médio de 16mm, inclinação de 45 ° no plano sagital e 15 ° no plano lateromedial, que a partir do tubérculo maxilar intercepta as lâminas ósseas da fossa pterigoide no osso esfenoide. A técnica consiste em utilizar um pilar de resistência do esqueleto facial, em que, fisiologicamente, as forças são descarregadas durante os ciclos de mastigação com dentes naturais. O implante, posicionado intraoralmente com o corpo e com o ápice no pilar, permite que as cargas sejam transferidas diretamente para o pilar, contornando os dentes e o osso alveolar. Implantes posicionados nesta região fornecem excelente suporte para os ossos posteriores sem necessidade de elevar o seio maxilar. Conclusão: Da literatura percebe-se que os implantes pterigóides têm alto índice de sucesso com mínimas complicaçõe

Hexagrid-Voronoi transition in structural patterns for tall buildings

In this paper, a first insight into the role that non-conventional structural patterns might play in the design of tall buildings is presented. The idea is to explore the mechanical properties of selected non-conventional structural patterns, in the form of both regular (Hexagrid) and irregular (Voronoi tessellation inspired) arrays, in order to assess their actual applicability in tall building design. For this aim, the concept of Representative Volume Element (RVE) and a classical homogenization-based micromechanical approach are employed for identifying the pattern units and deriving the relevant generalized stress-strain relationships. In the case of irregular patterns based on Voronoi diagrams, obtained by perturbing prescribed key geometrical features of hexagrids, a statistically significant sample of RVEs is defined on the basis of sensitivity analyses, and the related mechanical characterization is developed in statistical terms. Finally, a preliminary stiffness-based design procedure is proposed and applied to a tall building model with Voronoi exoskeleton. In conclusion, a discussion on the effectiveness of the design procedure and on the structural efficiency of the Voronoi patterns for tall buildings is presente

Percepción de control, frustración, anímica y valore

En el marco de un proyecto de investigación que explora en el Bienestar desde una perspectiva psicosocial, se presenta en este trabajo resultados obtenidos a partir de poner en relación la percepción de control con la sensación de frustración anómica y los valores de los participantes. Son muchos los aspectos subjetivos que condicionan el bienestar de las personas, entre ellas se destaca la satisfacción que perciben con su vida, que emerge de la avenencia entre el individuo y su entorno tanto micro como macrosocial.Eje temático: Psicología social, institucional y comunitariaFacultad de Psicologí

Well-being, emotional climate, social problems perception and trust

Desde una perspectiva psicosocial, el estudio del bienestar y de las emociones experimentadas en un determinado contexto social permiten integrar en el análisis elementos que obstruyen o facilitan la relación que las personas mantienen con su entorno. En este marco, se realizó un estudio empírico con el objetivo de poner en relación el bienestar psicológico y social con el clima emocional, la percepción de problemas sociales y la confianza institucional. La muestra es intencional, compuesta por 947 sujetos de varias ciudades de Argentina. Se observan buenos niveles de bienestar psicológico y social, una percepción de clima emocional negativo, de baja confianza institucional y de alta percepción de problemas sociales. Las mujeres muestran un bienestar más relacional y de más alto contexto que los hombres. El incremento en la edad se asocia a la vivencia de mayor autonomía y de mayor sensación de control, aunque también a una mirada más cínica del mundo.From a psycho-sociological perspective, well-being and culture framed emotional experiences study allow the integration of elements which obstacle or facilitate the relationships people maintain with social environment. In this frame, an empirical study was carried out in order to explore the relationship between psychological and social well-being with emotional climate, social problem's perception and institutional trust. A convenience sample was used composed by 947 participants from different argentines cities. Accurate levels of psychological and social well being are observed, but also high levels of a negative emotional climate, social problem's perception and institutional distrust. Females show a more relational and high context well-being in comparison with males. Age increasing seems associated with greater autonomy and sense of control but also with a more realistic or cynic view of social events.Fil: Zubieta, Elena Mercedes. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Psicología; ArgentinaFil: Muratori, Marcela. Universidad de Buenos Aires. Facultad de Psicología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Mele, Silvia Viviana. Universidad de Buenos Aires. Facultad de Psicología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Clima social emocional, confianza en las instituciones y percepción de problemas sociales

En el marco de una investigación que indaga distintas dimensiones del bienestar psicosocial los objetivos del presente trabajo son evaluar si existen relaciones entre los problemas sociales percibidos, la confianza que las personas tienen hacia las instituciones, el poder atribuido a ellas y el clima emocional social, evaluar sus niveles y probables diferencias en función de aspectos tales como el género, el auto-posicionamiento ideológico y el lugar de residencia.Eje temático: Psicología social, institucional y comunitariaFacultad de Psicologí

Clima social emocional, confianza en las instituciones y percepción de problemas sociales

En el marco de una investigación que indaga distintas dimensiones del bienestar psicosocial los objetivos del presente trabajo son evaluar si existen relaciones entre los problemas sociales percibidos, la confianza que las personas tienen hacia las instituciones, el poder atribuido a ellas y el clima emocional social, evaluar sus niveles y probables diferencias en función de aspectos tales como el género, el auto-posicionamiento ideológico y el lugar de residencia.Eje temático: Psicología social, institucional y comunitariaFacultad de Psicologí

In vivo longitudinal study of rodent skeletal muscle atrophy using ultrasonography

Muscle atrophy is a widespread ill condition occurring in many diseases, which can reduce quality of life and increase morbidity and mortality. We developed a new method using non-invasive ultrasonography to measure soleus and gastrocnemius lateralis muscle atrophy in the hindlimb-unloaded rat, a well-Accepted model of muscle disuse. Soleus and gastrocnemius volumes were calculated using the conventional truncated-cone method and a newly-designed sinusoidal method. For Soleus muscle, the ultrasonographic volume determined in vivo with either method was linearly correlated to the volume determined ex-vivo from excised muscles as muscle weight-To-density ratio. For both soleus and gastrocnemius muscles, a strong linear correlation was obtained between the ultrasonographic volume and the muscle fiber cross-sectional area determined ex-vivo on muscle cryosections. Thus ultrasonography allowed the longitudinal in vivo evaluation of muscle atrophy progression during hindlimb unloading. This study validates ultrasonography as a powerful method for the evaluation of rodent muscle atrophy in vivo, which would prove useful in disease models and therapeutic trials