SUSY Soft Breaking Terms from String Scenarios

The general SUSY soft breaking terms for a large class of phenomenologically relevant string scenarios (symmetric orbifolds) are given. They show a certain lack of universality, but not dangerous for flavor changing neutral currents. To get more quantitative results a specific SUSY breaking mechanism has to be considered, namely gaugino condensation in the hidden sector. Then, it turns out that squark and slepton masses tend to be much larger than scalar masses ($m_{\phi} > 10 M_a$), which probably is a quite general fact. Experimental bounds and the requirement of a successful electroweak breaking without fine tuning impose further restrictions on the soft breaking terms. As a consequence the gluino and chargino masses should be quite close to their present experimental limits, whereas squark and slepton masses should be much higher (> 1 TeV).Comment: (Talk presented at the SUSY-93 Conference, Boston, March 29 - April 2, 1993), 11 pages, CERN--TH.6922/9

Probabilistic metrology or how some measurement outcomes render ultra-precise estimates

We show on theoretical grounds that, even in the presence of noise, probabilistic measurement strategies (which have a certain probability of failure or abstention) can provide, upon a heralded successful outcome, estimates with a precision that exceeds the deterministic bounds for the average precision. This establishes a new ultimate bound on the phase estimation precision of particular measurement outcomes (or sequence of outcomes). For probe systems subject to local dephasing, we quantify such precision limit as a function of the probability of failure that can be tolerated. Our results show that the possibility of abstaining can set back the detrimental effects of noise.Comment: Improved version of arXiv:1407.6910 with an extended introduction where we clarify our approach to metrology, and probabilistic metrology in particular. Changed titl

Gender Gap and School Differential Effects in Mathematics in Chilean Primary Schools

Despite the systematic recognition of large gender gaps against girls in mathematics performance in Chile, the role of schools in explaining this gap has been comparatively unexplored. This paper analyses a longitudinal dataset to explore within and between school variation of Chilean primary schools in promoting attainment and progress of girls and boys. In order to reflect the hierarchical nature of the educational data, Multilevel modelling is used, with 163,044 students, nested within 3,355 schools, within 310 Municipalities to fit Raw, Contextualised Attainment and Value-Added models. The results indicate a small but significant gender differential school effect in progress in Chilean primary schools. Moreover, differences in effectiveness played a significant role, as girls over performed boys in less effective schools, but the opposite was true in more effective schools. Finally, the study concludes that the Chilean gender gap needs to be addressed within, but mainly beyond schools

Agregar o no agregar valor contextual en lenguaje: un estudio de caso instrumental en dos establecimientos chilenos de educación media

Este artículo reporta un estudio de caso cualitativo (Stake, 1995) en dos establecimientos secundarios chilenos orientado a examinar los procesos y/o dimensiones que pueden explicar las diferencias observadas en las puntuaciones de Valor Agregado Contextual (VAC) en el sector de lenguaje, ámbito poco estudiado en Chile y más ligado a la efectividad general que las matemáticas (Sammons, Thomas & Mortimore, 1997). Tras el análisis estadístico multinivel (Goldstein, 1995) de una muestra longitudinal de una cohorte de 176.896 estudiantes anidados en 2.283 establecimientos que rindieron el SIMCE en 8º básico y 2º medio en 2004-2006 y sus respectivos cuestionarios familiares, se utilizaron las puntuaciones del VAC para seleccionar un establecimiento que agregó valor y otro que no. Complementando un marco analítico-conceptual preexistente (Scheerens, Glas, & Thomas, 2003), el estudio identificó 11 dimensiones diferentes y 5 similarmente problemáticas en los establecimientos. Estas dimensiones complementan y extienden las conclusiones de un estudio seminal de escuelas efectivas en Chile (Belleï, Muñoz-Stuardo, Pérez, & Raczynski, 2004). Esta nueva evidencia, tentativa y exploratoria, inscribe las características de los establecimientos secundarios chilenos dentro de la literatura más amplia sobre efectividad educacional, buscando contribuir al nuevo marco de evaluación vigente en Chile con el potencial de informar y mejorar las políticas y prácticas educativas

Girl protagonists of Chilean dictatorship novels for the young

Narratives for children about Augusto Pinochet's dictatorship in Chile (1973–89) written by the sons and daughters of that era constitute a recognised genre. For the most part the genre features boy characters who not only have voice and choice, but also unrealistically win the fight against the oppressors. This paper examines two of the rare works with girl protagonists, paying attention to how their voices are constructed: Mariana Osorio Gumá's Tal vez vuelvan los pájaros [Maybe the birds will return] (Mexico, 2013) and Matilde by Carola Martínez Arroyo (Argentina, 2016). I apply Deleuze's theories about the gaze to girls to identify patterns that afford the construction of ‘lucid’ protagonists in terms of recurring modes of language production (silence, ordered discourse, invention), giving rise to inquisitive girls. Through the construction of a girl's lucid gaze, which can withstand and narrate the horrors of the dictatorship, these novels offer young audiences a powerful space for historic and collective memory

Unfolding Rates for the Diffusion-Collision Model

In the diffusion-collision model, the unfolding rates are given by the likelihood of secondary structural cluster dissociation. In this work, we introduce an unfolding rate calculation for proteins whose secondary structural elements are $\alpha$-helices, modeled from thermal escape over a barrier which arises from the free energy in buried hydrophobic residues. Our results are in good agreement with currently accepted values for the attempt rate.Comment: Shorter version of cond-mat/0011024 accepted for publication in PR

TikTok’s influence on Generation Z’s Buying Habits and Behavior

As the digital era progresses, we continue to see how certain platforms capture the interest of various generations. Back then, Myspace rapidly appealed to millennials, and Facebook did the same with baby boomers. Today, TikTok is following their steps as it gains the interest of Generation Z in technologically advanced ways. In addition to providing entertainment, this short-video platform is now the go-to place to look for reviews of products or services. Due to this, the platform may be transforming how this age group behaves as a consumer. The overall purpose of this project was to further examine the impact this platform has on this generation and the reasons why they favor it over other social networking sites. This project will provide a general overview of TikTok, make comparisons to other social media platforms, and explain how and why it might be valuable for those in the marketing, advertising, or public relations fields

Effect of spin-orbit interaction on a magnetic impurity in the vicinity of a surface

We propose a new mechanism for surface-induced magnetic anisotropy to explain the thickness-dependence of the Kondo resistivity of thin films of dilute magnetic alloys. The surface anisotropy energy, generated by spin-orbit coupling on the magnetic impurity itself, is an oscillating function of the distance d from the surface and decays as 1/d^2. Numerical estimates based on simple models suggest that this mechanism, unlike its alternatives, gives rise to an effect of the desired order of magnitude.Comment: 4 pages, 4 figure