1,018 research outputs found
El cuento es la selva : lectura crítica-ecológica de Los Cuentos de la Selva de Horacio Quiroga
Utilizo la perspectiva crítica ecológica para aproximarme a Los cuentos de la selva (1918) de Horacio Quiroga con el fin de reflexionar sobre lo que he denominado el decir ecológico. Este último implica analizar cómo, en lo dicho por los personajes-animales de los cuentos quiroguianos, se revela una forma de comunicación "selvática". Los animales hablan, pero no como humanos. Usan las palabras, pero éstas, más que servir en la discusión de problemas históricamente relevantes para la humanidad (el alma, la razón, etc.), reflejan el suceder de la naturaleza. Las palabras funcionan como un ecosistema. Los diálogos de tigres y boas, las expresiones de los tucanes, etc., están determinados por una preocupación particular: la selva como acontecimiento. En tal caso, podríamos afirmar que Quiroga imagina la selva creando personajes capaces de "hablar el verde" y "dialogar el hábitat".The main purpose of this article is to use a critical and ecological approach to read Horacio Quiroga's text Los cuentos de la selva (1918) so to think about, what I have intended to name, ecological discourse. In order to achieve this objective, I will analyze how character's speech reveals a "jungle communication". Animals talk but not like human beings do. They use words to talk about native life but they do not talk about important human topics such as soul, thought, and so on. Words are used as an ecological system. Tigers and boas dialogues and toucan expressions have a particular interest: jungle as an event. We can affirm that Quiroga imagines jungle creating characters able to "talk the green" and to "dialogue the habitat".Utilitzo la perspectiva crítica ecològica per aproximar-me a Los cuentos de la selva (1918) d'Horacio Quiroga amb la finalitat de reflexionar sobre el que he anomenat el dir ecològic. Això últim implica analitzar com, en allò dit per els personàtges-animals dels contes de Quiroga, es revela com una forma de comunicació "selvàtica". Els animals parlen, però no com humans. Utilitzen les paraules, però aquestes, més que servir en la discussió de problemes històricament rellevants per la humanitat (l'ànima, la raó, etc.), reflexen els aconteixements de la naturalesa. Les paraules funcionen com un ecosistema. Els diàlegs dels tigres, els enunciats de les boes, les expressions dels tucans, etc., estan determinats per una preocupació particular: la selva com a aconteixement. En aquest cas, podríem afirmar que Quiroga imagina la selva creant personàtges capaços de "parlar en verd" i "dialogar l'hàbitat".Horacio Quirogaren Los cuentos de la selva (1918) ipuinetara hurbiltzeko kritika ekologikoaren ikuspuntua erabiltzen dut, esamolde ekologikoa izendatu dudanari buruz hausnarketa bat egite aldera. Azken honen zera dakar, Quirogaren ipuinetako pertsonaia-animaliek diotena "oihaneko" komunikazio mota bezala aztertu behar dela. Animaliek hitz egiten dute, baina gizakiek ez bezala. Hitzak erabiltzen dituzte, baina hauek, gizateriaren arazo historikoki nabarmenak (arima, arrazoia, e.a.) tratatzeko baino, naturaren bilakaera islatzen dute. Hitzek ekosistema bezala funtzionatzen dute. Tigreen elkarrizketak, boen esaldiak, tukanen adierazpideak, e.a. kezka berezi batek mugatuta daude: oihana gertakari bezala. Kasu honetan esan dezakegu Quirogak oihana irudikatzen duela, "berdea" adierazi eta "habitata" solastatu ahal duten pertsonaiak sortuta
Factorizing the time evolution operator
There is a widespread belief in the quantum physical community, and in
textbooks used to teach Quantum Mechanics, that it is a difficult task to apply
the time evolution operator Exp{-itH/h} on an initial wave function. That is to
say, because the hamiltonian operator generally is the sum of two operators,
then it is a difficult task to apply the time evolution operator on an initial
wave function f(x,0), for it implies to apply terms operators like (a+b)^n. A
possible solution of this problem is to factorize the time evolution operator
and then apply successively the individual exponential operator on the initial
wave function. However, the exponential operator does not directly factorize,
i. e. Exp{a+b} is not equal to Exp{a}Exp{b}. In this work we present a useful
procedure for factorizing the time evolution operator when the argument of the
exponential is a sum of two operators, which obey specific commutation
relations. Then, we apply the exponential operator as an evolution operator for
the case of elementary unidimensional potentials, like the particle subject to
a constant force and the harmonic oscillator. Also, we argue about an apparent
paradox concerning the time evolution operator and non-spreading wave packets
addressed previously in the literature.Comment: 24 pages; added references; one figure change
Identifying clusters of anomalous payments in the salvadorian payment system
We develop an unsupervised methodology to group payments and identify possible anomalies. With our methodology, we identify clusters based on a set of network features, using transactional (unlabeled) information from a systemically important payment system of El Salvador. We first preprocess network features, such as degree and strength, through a principal components analysis we reduce the dimensionality of the newly defined data, then we place the main variables into clustering algorithms (k-means and DBSCAN) to analyze anomalous payments. We then analyze, these clusters using random forest to obtain the main network feature. Our results suggest that the proposed methodology works very well to detect anomalous payments, and it is very important to study the case of El Salvador, because of the recent restructuring of the Massive Payment System in El Salvador (promoted by the Transfer365 project), because the authorities want to increase financial inclusion. This change will make the SPM available to the public, to diversify services and incorporate more participants because, historically, it has operated with only three active participants. We expected that Transfer365 will interconnect the LBTR participants' systems with their banking core, the systems of the Ministry of Finance, and other authorized participants to channel large payment flows. Then, identifying possible anomalies through methodology will enhance risk monitoring and management by payment systems overseers
Verrucous carcinoma of the oral mucosa: an epidemiological and follow-up study of patients treated with surgery in 5 last years
Introduction: Oral Verrucous Carcinoma (OVC) is described apart of the Squamous Cell Carcinoma (SCC) due to
its specific properties. The objective of our study is to show our series of cases of OVC and to compare with the
SCC in terms of clinical manifestations, epidemiology, histopathology, treatment and follow-up.
Material and Methods: This is a retrospective study of all the OVC treated in our department between January-
2007 and December-2011. The analyzed variables were sex, age, localization in the oral cavity, histopathology,
number of biopsies needed to diagnose OVC, TNM classification, treatment and recurrences during follow-up.
Results: Our sample was composed by n=14 patients, 57% female, with a mean age of 69.14 years. The most com
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mon localization was buccal mucosa (n=5). Seven patients were diagnosed of OVC with the first biopsy. TNM
classification was: pT1: 7 patients, pT2: 3 patients, pT3: 3 patients, pT4: 1 patient. No cervical metastases were
observed either in cervical neck dissection or during the follow-up of the patients. The treatment was surgery with
clinical resection margins up to 1 cm in all cases, followed by radiotherapy in selected cases. Only n=1 patient
(7.69%) presented a recurrence after 34 months of follow-up. The overall survival rate was 92.85%.
Conclusions: In our population, OVC represents the 6.16% of all oral cavity and oropharynx cancer, and is more
frequent in female patients above 70 years old. It uses to rise over a previous lesion, and usually affects the buccal
mucosa. In patients with high suspicious lesions, more than one biopsy may be needed to diagnose OVC. No pa
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tient showed cervical dissemination. In our experience, treatment based on local resection, without cervical neck
dissection, could be a good option for these patients
Tectónica activa de la Cuenca de Málaga: evidencias en marcadores morfotectónicos (Cordillera Bética Occidental, España)
The Malaga Basin is located in the westernmost part of the Betic Cordillera. This alpine cordillera in the south of Spain is the most active region of the Iberian Peninsula. Some of the most destructive earthquakes occurred historically in Spain took place within the Malaga Basin. In this work we focus on geomorphic and morphotectonic observations in the aim of finding active tectonic structures that could be seismogenic sources. First, we study the spatial arrangement and age of the Quaternary alluvial fan system as well as the drainage pattern of the basin, followed by the analysis of the distribution of regional markers like marine erosive surfaces and the extend of Pliocene marine deposits in the Malaga Basin. The tectonic structures inferred as active by the morphotectonic analysis are grouped into four main families: N60º-85ºE folds associated with blind thrust faults, N20º-30ºE and N40º-50ºE high angle dip-slip faults, and N165º-170ºE tear faults. Finally, their seismic potential in terms of maximum moment magnitude (Mw) is assessed by means of empirical relationships, varying between 6.0 and 7.0 depending on the hypothesis considered.La cuenca de Málaga se sitúa en la parte más occidental de la cordillera Bética. En esta cordillera alpina del sur de España se han localizado algunos de los terremotos más destructivos ocurridos históricamente en la península Ibérica. En este trabajo se estudian algunos de los aspectos geomorfológicos de la cuenca del Málaga con el fin de identificar las estructuras tectónicas activas que pudiesen ser fuentes sismogénicas. Se estudia la distribución y edad del sistema de abanicos aluviales de la cuenca, así como la red de drenaje. También se analiza la distribución regional de marcadores tectónicos pliocenos, como superficies de erosión marina y los depósitos sedimentarios de este periodo transgresivo. Se han identificado varias estructuras tectónicas activas que han sido agrupadas en cuatro familias: pliegues N60º-85ºE asociados con falla inversas ciegas, fallas de alto buzamiento con salto en la vertical N20º-30ºE y N40º-50ºE, y fallas de transferencia N165º-170ºE. En base a relaciones empíricas se ha estimado un potencial sísmico para las fallas identificadas, obteniéndose valores de magnitud momento (Mw) entre 6,0 y 7,0
The 2-79 keV X-ray Spectrum of the Circinus Galaxy with NuSTAR, XMM-Newton and Chandra: a Fully Compton-Thick AGN
The Circinus galaxy is one of the nearest obscured AGN, making it an ideal
target for detailed study. Combining archival Chandra and XMM-Newton data with
new NuSTAR observations, we model the 2-79 keV spectrum to constrain the
primary AGN continuum and to derive physical parameters for the obscuring
material. Chandra's high angular resolution allows a separation of nuclear and
off-nuclear galactic emission. In the off-nuclear diffuse emission we find
signatures of strong cold reflection, including high equivalent-width neutral
Fe lines. This Compton-scattered off-nuclear emission amounts to 18% of the
nuclear flux in the Fe line region, but becomes comparable to the nuclear
emission above 30 keV. The new analysis no longer supports a prominent
transmitted AGN component in the observed band. We find that the nuclear
spectrum is consistent with Compton-scattering by an optically-thick torus,
where the intrinsic spectrum is a powerlaw of photon index ,
the torus has an equatorial column density of cm and the intrinsic AGN keV luminosity is
erg/s. These values place Circinus along the same
relations as unobscured AGN in accretion rate-vs- and -vs-
phase space. NuSTAR's high sensitivity and low background allow us to study the
short time-scale variability of Circinus at X-ray energies above 10 keV for the
first time. The lack of detected variability favors a Compton-thick absorber,
in line with the the spectral fitting results.Comment: Accepted for publication in Ap
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