509 research outputs found
A Critical Analysis of the Media Representations of Venezuelan Immigrants, Refugees, and Asylum-Seekers (Venezuelan IRAS) in Peru
The Venezuelan migration phenomenon is currently the second-largest external displacement crisis worldwide. As the number of Venezuelans leaving their country has risen, migration policies in Latin American countries have become more restrictive. In Peru, the second-largest recipient of Venezuelans and the largest host of Venezuelan asylum-seekers worldwide, the securitization of migration policies started in August 2018 with a passport requirement for Venezuelans, and intensified in June 2019 with another, yet virtually unreachable requirement: the Humanitarian Visa. Utilizing media-framing theory and Critical Discourse Analysis (CDA), this study analyzed the media discourse built by El Comercio newspaper between April 1 and June 30, 2019. CDA was performed on a total of 63 news stories of different journalistic genres, and findings are consistent with the academic literature pertaining to the media representations of immigrants, refugees, and asylum-seekers around the globe. Overall, there is a tendency to frame Venezuelans negatively, portraying them as threats and accusing them of Peru’s structural flaws. In addition, specific findings suggest a lack of rigour in the journalistic practices of El Comercio as well as larger discursive strategies involving political purposes
"Las representaciones del 'Caso Conga' en la prensa escrita peruana" : análisis crítico e interpretación de los discursos periodísticos de portada de los diarios El Comercio y La República durante los primeros meses del conflicto socioambiental en torno al proyecto minero Conga
El ‘Caso Conga’ es parte de los numerosos conflictos socioambientales que se han concentrado en torno a los grandes proyectos extractivos en el Perú, los que, a su vez, bajo el concepto del desarrollo de tipo neoliberal, son concebidos como las bases fundamentales del éxito económico nacional.
El Caso tiene lugar en Cajamarca —que, desde 1991, es una de las principales regiones productoras de oro en Perú— y ha sido cubierto por medios masivos y alternativos de comunicación desde setiembre de 2011 hasta la actualidad, con una mayor presencia en los años 2011 y 2012.
En esta tesis nos enfocamos en medios masivos, pues consideramos que estos actúan como sistemas de transmisión de mensajes y símbolos para el ciudadano medio. Entre sus funciones se encuentra, por ejemplo, el inculcar al individuo valores, creencias y códigos de comportamiento —representaciones— que le harán integrarse en las estructuras institucionales de la sociedad (Chomsky y Herman 1995: 21). En una sociedad donde la riqueza se concentra en un pequeño grupo de poder, estas representaciones tienen un trasfondo ideológico que busca satisfacer los intereses de este grupo.
Es por ello que los objetivos de esta tesis son el análisis crítico y la interpretación de los discursos periodísticos, como representaciones que construyen una realidad, sobre este conflicto y sus actores. Para ello, analizamos las portadas de El Comercio y La República, diarios con una elevada lectoría, prestigio, líneas editoriales generalmente opuestas y que pertenecen a la “gran prensa” nacional, concentrando el poder económico del sector.
Partimos de la hipótesis de que estos diarios construyen discursos del Caso con el fin de mantener el statu quo de su grupo mediático y, por ende, de defender intereses empresariales y políticos. Así, encontramos que los diarios, a través de ciertas estrategias discursivas, perpetúan, entre otros esquemas ideológicos, la polarización entre el ‘Nosotros’ y los ‘Otros’, el ‘Mito del diálogo’ y la ‘Criminalización de la protesta’. Además, validamos la teoría del framing —que tiene como fin el poner en evidencia las representaciones de la realidad que construyen los medios a través de sus encuadres— como recurso periodístico y como sustento del discurso ideológico.Tesi
Nonlinear Supersymmetric (Darboux) Covariance of the Ermakov-Milne-Pinney Equation
It is shown that the nonlinear Ermakov-Milne-Pinney equation
obeys the property of covariance under
a class of transformations of its coefficient function. This property is
derived by using supersymmetric, or Darboux, transformations. The general
solution of the transformed equation is expressed in terms of the solution of
the original one. Both iterations of these transformations and irreducible
transformations of second order in derivatives are considered to obtain the
chain of mutually related Ermakov-Milne-Pinney equations. The behaviour of the
Lewis invariant and the quantum number function for bound states is
investigated. This construction is illustrated by the simple example of an
infinite square well.Comment: 8 page
Ermakov-Lewis angles for one-parameter supersymmetric families of Newtonian free damping modes
We apply the Ermakov-Lewis procedure to the one-parameter damped modes
\tilde{y} recently introduced by Rosu and Reyes, which are related to the
common Newtonian free damping modes y by the general Riccati solution [H.C.
Rosu and M. Reyes, Phys. Rev. E 57, 4850 (1998), physics/9707019]. In
particular, we calculate and plot the angle quantities of this approach that
can help to distinguish these modes from the common y modesComment: 6 pages, twocolumn, 18 figs embedded, only first 9 publishe
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Phosphorylation of Shox2 Is Required for Its Function to Control Sinoatrial Node Formation
Background: Inactivation of Shox2, a member of the short‐stature homeobox gene family, leads to defective development of multiple organs and embryonic lethality as a result of cardiovascular defects, including bradycardia and severe hypoplastic sinoatrial node (SAN) and sinus valves, in mice. It has been demonstrated that Shox2 regulates a genetic network through the repression of Nkx2.5 to maintain the fate of the SAN cells. However, the functional mechanism of Shox2 protein as a transcriptional repressor on Nkx2.5 expression remains completely unknown. Methods and Results: A specific interaction between the B56δ regulatory subunit of PP2A and Shox2a, the isoform that is expressed in the developing heart, was demonstrated by yeast 2‐hybrid screen and coimmunoprecipitation. Western blotting and immunohistochemical assays further confirmed the presence of phosphorylated Shox2a (p‐Shox2a) in cell culture as well as in the developing mouse and human SAN. Site‐directed mutagenesis and in vitro kinase assays identified Ser92 and Ser110 as true phosphorylation sites and substrates of extracellular signal‐regulated kinase 1 and 2. Despite that Shox2a and its phosphorylation mutants possessed similar transcriptional repressive activities in cell cultures when fused with Gal4 protein, the mutant forms exhibited a compromised repressive effect on the activity of the mouse Nkx2.5 promoter in cell cultures, indicating that phosphorylation is required for Shox2a to repress Nkx2.5 expression specifically. Transgenic expression of Shox2a, but not Shox2a‐S92AS110A, mutant in the developing heart resulted in down‐regulation of Nkx2.5 in wild‐type mice and rescued the SAN defects in the Shox2 mutant background. Last, we demonstrated that elimination of both phosphorylation sites on Shox2a did not alter its nuclear location and dimerization, but depleted its capability to bind to the consensus sequences within the Nkx2.5 promoter region. Conclusions: Our studies reveal that phosphorylation is essential for Shox2a to repress Nkx2.5 expression during SAN development and differentiation
Alcohol, Brain Derived Neurotrophic Factor and Obesity among People Living with HIV
Introduction In an expanding HAART era, obesity has become a health problem among persons living with HIV (PLWH). Whereas the rising level of obesity has been largely attributed to poor nutrition and exercise habits, differences in biological factors may explain why some individuals gain more weight than others. Thus, our main goal is to prospectively determine in PLWH whether plasma brain-derived neurotrophic factor (BDNF), and hazardous alcohol use (HAU), two overlooked but highly prevalent conditions among PLWH, correlate with an adverse anthropometric profile. Also to test whether these relationships varied in men and women Methods The Platelets mediating Alcohol and HIV Damage Study (PADS) is an ongoing multiethnic study of 400 PLWH receiving regular medical care in South Florida (37% females and 63% males). Semi-annual visits consisted of a medical exam, including anthropometrics to assess both general (body mass index: BMI) and central obesity (waist and hip circumferences). Participants also completed health history questionnaires, and provided a fasting blood sample to obtain BDNF and immune and biochemical assessments. Results A sizable proportion of participants met the National Institutes of Health definition of overweight (BMI = 25?29.9 kg/m2; 26%) and obese (BMI ? 30 kg/m2; 35%). Women were more likely to be obese than men (OR=4.9, 95% CI=2.9?8.2, p=0.0001). Compared to men, women also exhibited the highest mean plasma BDNF levels (9,959 ± 6,578 vs. 7,470 ± 6,068 pg/ml, p=0.0001). Additional analyses indicated that HAU, particularly heavy drinkers, had the smallest waist and hip circumferences if they were males, but the opposite if they were females. High BDNF levels were positively correlated with BMI. Linear regression analysis revealed that gender, BDNF, and HAU were the best predictors of BMI. Conclusion In summary, our findings offer novel insights into the relationships between BDNF, and alcohol use among overweight and obese PLWH. Our results also suggest that these relationships may be inherently different by gender
Latitudinal Asymmetry in the Dayside Atmosphere of WASP-43b
We present two-dimensional near-infrared temperature maps of the canonical hot Jupiter WASP-43b using a phase-curve observation with JWST NIRSpec/G395H. From the white-light planetary transit, we improve constraints on the planet’s orbital parameters and measure a planet-to-star radius ratio of 0.15883−0.00053+0.00056 . Using the white-light phase curve, we measure a longitude of maximum brightness of 6.9−0.°5+0.°5 east of the substellar point and a phase-curve offset of 10.0−0.°8+0.°8 . We also find a ≈4σ detection of a latitudinal hotspot offset of −13.4−1.°7+3.°2 , the first significant detection of a nonequatorial hotspot in an exoplanet atmosphere. We show that this detection is robust to variations within planetary parameter uncertainties, but only if the transit is used to improve constraints, showing the importance of transit observations to eclipse mapping. Maps retrieved from the NRS1 and NRS2 detectors are similar, with hotspot locations consistent between the two detectors at the 1σ level. Our JWST data show brighter (hotter) nightsides and a dimmer (colder) dayside at the shorter wavelengths relative to fits to Spitzer 3.6 and 4.5 μm phase curves. Through comparison between our phase curves and a set of general circulation models, we find evidence for clouds on the nightside and atmospheric drag or high metallicity reducing the eastward hotspot offset
ACCESS: A Visual to Near-infrared Spectrum of the Hot Jupiter WASP-43b with Evidence of , but no evidence of Na or K
We present a new ground-based visual transmission spectrum of the hot Jupiter
WASP-43b, obtained as part of the ACCESS Survey. The spectrum was derived from
four transits observed between 2015 and 2018, with combined wavelength coverage
between 5,300 \r{A}-9,000 \r{A} and an average photometric precision of 708 ppm
in 230 \r{A} bins. We perform an atmospheric retrieval of our transmission
spectrum combined with literature HST/WFC3 observations to search for the
presence of clouds/hazes as well as Na, K, H, and planetary
absorption and stellar spot contamination over a combined spectral range of
5,318 \r{A}-16,420 \r{A}. We do not detect a statistically significant presence
of Na I or K I alkali lines, or H in the atmosphere of WASP-43b. We
find that the observed transmission spectrum can be best explained by a
combination of heterogeneities on the photosphere of the host star and a clear
planetary atmosphere with . This model yields a log-evidence of
higher than a flat (featureless) spectrum. In particular, the
observations marginally favor the presence of large, low-contrast spots over
the four ACCESS transit epochs with an average covering fraction and temperature contrast . Within the planet's atmosphere, we recover a log
volume mixing ratio of , which is consistent with
previous abundance determinations for this planet.Comment: 27 pages, 18 figures, 7 tables. Accepted for publication in AJ.
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ACCESS: An optical transmission spectrum of the high-gravity, hot Jupiter HAT-P-23b
We present a new ground-based visible transmission spectrum of the
high-gravity, hot Jupiter HAT-P-23b, obtained as part of the ACCESS project. We
derive the spectrum from five transits observed between 2016 and 2018, with
combined wavelength coverage between 5200 {\AA} - 9269 {\AA} in 200 {\AA} bins,
and with a median precision of 247 ppm per bin. HAT-P-23b's relatively high
surface gravity (g ~ 30 m/s^2), combined with updated stellar and planetary
parameters from Gaia DR2, gives a 5-scale-height signal of 384 ppm for a
hydrogen-dominated atmosphere. Bayesian models favor a clear atmosphere for the
planet with the tentative presence of TiO, after simultaneously modeling
stellar contamination, using spots parameter constraints from photometry. If
confirmed, HAT-P-23b would be the first example of a high-gravity gas giant
with a clear atmosphere observed in transmission at optical/NIR wavelengths;
therefore, we recommend expanding observations to the UV and IR to confirm our
results and further characterize this planet. This result demonstrates how
combining transmission spectroscopy of exoplanet atmospheres with long-term
photometric monitoring of the host stars can help disentangle the exoplanet and
stellar activity signals.Comment: 28 pages, 18 Figures, accepted for publication in AJ. arXiv admin
note: text overlap with arXiv:1911.0335
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