3,062 research outputs found
Quark masses without Yukawa hierarchies
A model based on the local gauge group SU(3)_c x SU(3)_L x U(1)_X without
particles with exotic electric charges is shown to be able to provide the quark
mass spectrum and their mixing, by means of universal see-saw mechanisms,
avoiding a hierarchy in the Yukawa coupling constants.Comment: 7 pages, 1 eps figure. Published in Europhysics Letter
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Trump-induced anxiety among Latina/os
During the 2016 election, Donald Trump castigated unauthorized immigrants as “murderers and rapists.” During his presidency, he continued the use of this rhetoric, explicitly linking unauthorized migrants to threatening narratives. Here, we consider three questions: Did Donald Trump and his immigration positions serve as an “anxiety trigger” for Latina/os? Are individuals with contextually stigmatized attributes especially sensitive to Trump and his policy proposals? Is Spanish language itself, an attribute negatively stigmatized in the context of the immigration issue, sufficient to increase deportation anxiety? Utilizing survey experiments of Latina/os, we demonstrate that exposure to a Trump immigration cue is sufficient to increase anxiety about deportation. We also demonstrate that stigmatized attributes predict anxiety, but do not moderate the effect of the Trump cue. Lastly, we provide evidence that survey language affects anxiety among Latina/os. In Studies 1 (n = 736) and 2 (n = 1,040), we show that exposure to information about Trump’s immigration agenda significantly increases reports about deportation anxiety. In Study 3 (n = 1,734), we show that the Trump exposure condition induces heightened anxiety but that Latina/o attributes (language proficiency and use, immigration status, assessed phenotype) and identity strength have an independent effect on deportation anxiety. In Study 4 (n = 775), we randomized bilingual respondents into Spanish or English language survey protocols and found that comparable bilinguals exposed to Spanish language report higher levels of anxiety compared to English-language survey takers
On Charge Quantization and Abelian Gauge Horizontal Symmetries
Under the assumption that there exists a local gauge horizontal symmetry
wich allows only for a top quark mass at tree level, we look for the
constraints that charge quatization and the family structure of the standard
model imposes on that symmetry.Comment: 13 pages, LaTeX, Acepted in Physics Letters
Light propagation through optical media using metric contact geometry
In this work, we show that the orthogonality between rays and fronts of light
propagation in a medium is expressed in terms of a suitable metric contact
structure of the optical medium without boundaries. Moreover, we show that
considering interfaces (modeled as boundaries) orthogonality is no longer
fulfilled, leading to optical aberrations and in some cases total internal
reflection. We present some illustrative examples of this latter point.Comment: 8 pages, 7 figure
Participatory Militias: An Analysis of an Armed Movement's Online Audience
Armed groups of civilians known as "self-defense forces" have ousted the
powerful Knights Templar drug cartel from several towns in Michoacan. This
militia uprising has unfolded on social media, particularly in the "VXM"
("Valor por Michoacan," Spanish for "Courage for Michoacan") Facebook page,
gathering more than 170,000 fans. Previous work on the Drug War has documented
the use of social media for real-time reports of violent clashes. However, VXM
goes one step further by taking on a pro-militia propagandist role, engaging in
two-way communication with its audience. This paper presents a descriptive
analysis of VXM and its audience. We examined nine months of posts, from VXM's
inception until May 2014, totaling 6,000 posts by VXM administrators and more
than 108,000 comments from its audience. We describe the main conversation
themes, post frequency and relationships with offline events and public
figures. We also characterize the behavior of VXM's most active audience
members. Our work illustrates VXM's online mobilization strategies, and how its
audience takes part in defining the narrative of this armed conflict. We
conclude by discussing possible applications of our findings for the design of
future communication technologies.Comment: Participatory Militias: An Analysis of an Armed Movement's Online
Audience. Saiph Savage, Andres Monroy-Hernandez. CSCW: ACM Conference on
Computer-Supported Cooperative Work 201
Degradación de la Clorofila Presente en (Spirogyra spp.) como Indicator Socio Ambiental de la Presencia de Plaguicidas organofosforados
En la presente investigación se estudió la alteración de la clorofila presente en Spirogyra spp. como indicador de la presencia de tres plaguicidas organofosforados: Curacrón, Malatión y Acefato, a través de ensayos realizados a diferentes concentraciones de los plaguicidas durante un lapso de 72 horas de exposición. Transcurrida la etapa experimental se pudo observar la pérdida de la coloración verde de las algas como resultado de la alteración de su pigmentación natural. El análisis de varianza realizado a los resultados de la medición de la absorbancia de las muestras demuestra una disminución de la concentración de clorofila, en comparación con las muestras testigo de los ensayos. La sensibilidad de las algas al ser expuestas a los plaguicidas organofosforados es una manifestación del alto potencial bioindicador de Spirogyra spp. Este estudio brinda a los agricultores de la comunidad de San Antonio la posibilidad de detectar de manera temprana la presencia de plaguicidas en sus fuentes de agua y abre las puertas a la investigación para posteriores aplicaciones. The alteration of the chlorophyll present in Spirogyra spp. was studied as an indicator of the presence of three organophosphorus pesticides, Curacron, Malathion and Acephate, with tests carried out at different concentrations of the pesticides during a period of 72 hours of exposure. After the experimental stage, it was possible to observe the loss of the green coloration of the algae as a result of the alteration of their natural pigmentation. The analysis of variance based on the results of the measurement of the absorbance of the samples demonstrated a decrease in the concentration of chlorophyll compared to the control samples from the trials. The sensitivity of algae to being exposed to organophosphorus pesticides is a manifestation of the high bioindicator potential of Spirogyra spp., which provides farmers in the community of San Antonio the possibility of early detection of the presence of pesticides in their sources of water, and it also opens the doors to research for subsequent applications
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