1,708 research outputs found

    Leptonic CP phases near the μ−τ\mu-\tau symmetric limit

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    The neutrino masses and mixings indicated by current neutrino oscillation experiments suggest that the neutrino mass matrix possesses an approximate μ−τ\mu-\tau exchange symmetry. In this study, we explore the neutrino parameter space and show that if a small μ−τ\mu-\tau symmetry breaking is considered, the Majorana CPCP phases must be unequal and non-zero independently of the neutrino mass scale. Moreover, a small μ−τ\mu-\tau symmetry breaking favors quasi-degenerate masses. We also show that Majorana phases are strongly correlated with the Dirac CPCP violating phase. Within this framework, we obtain robust predictions for the values of the Majorana phases when the experimental indications for the Dirac CPCP phase are used.Comment: 13 pages, 3 figures. Version accepted for publication in PL

    Moths fight back: arms race in the cloud forest

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    Moths and bats engage in a coevolutionary arm race, where the same signals bats use to find moths are being used by moths to avoid bats. Moths evolve not only behavioral but acoustic responses to avoid predation by bats. This research examines one small component of a complex, multispecies arm race between moths and bats. In this study we found that the moth Amastus hyalina displayed both flight and acoustic responses to ultrasonic stimuli. In tethered flight the tiger moth Amastus hyalina (Arctiinae) exhibits a complex array of reactions to ultrasonic tones that includes changes in flight and production of ultrasonic clicks. The changes in flight included change in wing beat frequency, amplitude of the stroke, a rotation of the wings, and deflection of the abdomen, legs, and antennae. The changes in flight displayed by moths reduce the cues that bats use for prey capture including the amplitude modulation of echoes from wingbeats. Moths produce the biggest returning echoes for frequencies between 20 to 35 kHz, which coincides with the frequencies used by most insectivorous bats in the location. The species of tiger moth that we studied is but one of many species at our field site, but we believe that similar antipredator mechanisms are widespread among tiger moths, and may also be found in other families of moths that have tympanic organs

    Remapping the U.S. Southwest : Early Mexican American Literature and the Production of Transnational Counterspaces, 1885-1958

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    This dissertation brings to light a legacy of Mexican American spatial resilience that troubles Anglo-centric constructions of the Southwest, its history, and cultural formation as a byproduct of westward expansionism. This project argues that early Mexican American writers offer an alternative paradigm of transnationalism for understanding the literature, culture, and geography of the U.S. Southwest as it has been imagined in Anglo American cultural production about the region. For early Mexican American writers, the Southwest was not a quaint literary region but a space of historic transnational zones of contact, commerce, and cultural geography where they maintained degrees of agency. I examine the writings of María Amparo Ruiz de Burton, Fray Angélico Chávez, Federico Ronstadt, and Américo Paredes for their transnational counterspaces. I use this term, which draws from spatial theories by Henri Lefebvre and Edward Soja, to describe their vocalizations of the Southwest produced in the face of their respective Anglo counterparts such as Willa Cather and other members of the Santa Fe and Taos writers colonies, Walter Noble Burns, J. Frank Dobie, and Walter Prescott Webb. I take an interdisciplinary approach dialoging with Chicano/a, borderlands, and American literary studies within a historical framework to chart how early Mexican American writings reclaim the region by mapping transnational heritages belonging to Mexican American and Chicano/a communities

    Remembering Hurricane Beulah: An Interview With Conjunto Legend Gilberto Perez On Hurricane Beulah Corridos, Commercialisim and Culture

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    An Interview with Conjunto music legend Gilberto Perez is presented, who has a prestigious career as a singer and accordionist. He talks about his experience of performing concerts, his band Gilberto Perez y Sus Compadres and band members and the significance of his corrido Las Crecientes de Beulah which is a narration of his experience at the time when a destructive hurricane Beulah had hit Rio Grande Valley in Texas, causing displacement of Mexicans as refugees

    Prevalencia de algunas enfermedades infecciosas reproductivas en bovinos de los resguardos indígenas San Francisco, Toribío Y Tacueyó (Cauca)

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    Determinar la prevalencia de algunas enfermedades infecciosas de carácter reproductivo en el ganado bovino en los resguardos indígenas San Francisco, Toribio y Tacueyó (Cauca). Materiales y métodos. Se recolectaron muestras sanguíneas en 30 vacas para determinar la prevalencia de Neospora caninum, Brucella abortus., Leptospira prajidno, Leptospira bovis, Leptospira pomona, virus de la diarrea viral bovina (BVDV) y el herpes virus bovino tipo 1 (BoHV-1). Las pruebas se realizaron por medio de ensayos de inmunoabsorción ligado a enzimas (ELISA), rosa de bengala y aglutinación microscópica (MAT). A partir de los datos recolectados se realizó un análisis descriptivo inicial y se estimaron las frecuencias de cada una de las enfermedades con sus respectivos intervalos de confianza del 95%. También, se estimaron las co-infecciones entre enfermedades y se realizó un modelo de regresión logística para determinar el efecto del hato, el resguardo, el componente racial, el grupo etario, el número de animales y el tamaño de la finca sobre la positividad a cada una de las enfermedades. Finalmente, a partir de los factores de riesgo significativos se calculó el odds ratio de cada uno de ellos. Todos los análisis se realizaron mediante el softwar

    neoliberalization and inequality in Medellín’s urban waterscape

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    Over the past two decades, Colombia has witnessed a significant shift in the overall legal and policy domain in the water sector in order to adjust to the demands imposed by neoliberal economic reforms. Particularly in urban areas, this reform model has been deeply contested as it failed to provide low-income population with access to affordable and adequate water supply services. This paper explores how the implementation of market-driven reforms in the water supply sector has become a key factor in reproducing patterns of unequal access to water. By drawing upon case-study research conducted in Medellín, Colombia, this study investigates the causal interconnection between the commercialization and transnationalization of the city’s public multi-utility company as a strategy to be competitive in a globalized environment on the one hand, and the increasing number of households disconnected from the formal water supply networks particularly in low-income areas for non-payment of bills, on the other hand. By bringing together work on urban political ecology and neoliberalization of nature, this paper illustrates how inequalities in access to water in Medellín’s waterscape are facilitated by governance structures which are articulated to neoliberal strategies, whose social power relations are simultaneously sustained by an intertwined set of socioeconomic mechanisms, discursive practices as well as technological infrastructures
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