Ice Core Evidence for a Second Volcanic Eruption Around 1809 in the Northern Hemisphere

A volcanic signal observed in ice cores from both polar regions six years prior to Tambora is attributed to an unknown tropical eruption in 1809. Recovery of dacitic tephra from the 1809 horizon in a Yukon ice core ( Eclipse) that is chemically distinct from andesitic 1809 tephra found in Antarctic ice cores indicates a second eruption in the Northern Hemisphere at this time. Together with the similar magnitude and timing of the 1809 volcanic signal in the Arctic and Antarctic, this could suggest a large tropical eruption produced the sulfate and Antarctic tephra and a minor Northern Hemisphere eruption produced the Eclipse tephra. Nonetheless, the possibility that there were coincidental eruptions of similar magnitude in both hemispheres, rather than a single tropical eruption, should not be discounted. Correctly attributing the source of the 1809 volcanic signal has important implications for modeling the magnitude and latitudinal distribution of volcanic radiative forcing.

ANALYTICAL MODELS OF EXOPLANETARY ATMOSPHERES. I. ATMOSPHERIC DYNAMICS VIA THE SHALLOW WATER SYSTEM

Within the context of exoplanetary atmospheres, we present a comprehensive linear analysis of forced, damped, magnetized shallow water systems, exploring the effects of dimensionality, geometry (Cartesian, pseudo-spherical, and spherical), rotation, magnetic tension, and hydrodynamic and magnetic sources of friction. Across a broad range of conditions, we find that the key governing equation for atmospheres and quantum harmonic oscillators are identical, even when forcing (stellar irradiation), sources of friction (molecular viscosity, Rayleigh drag, and magnetic drag), and magnetic tension are included. The global atmospheric structure is largely controlled by a single key parameter that involves the Rossby and Prandtl numbers. This near-universality breaks down when either molecular viscosity or magnetic drag acts non-uniformly across latitude or a poloidal magnetic field is present, suggesting that these effects will introduce qualitative changes to the familiar chevron-shaped feature witnessed in simulations of atmospheric circulation. We also find that hydrodynamic and magnetic sources of friction have dissimilar phase signatures and affect the flow in fundamentally different ways, implying that using Rayleigh drag to mimic magnetic drag is inaccurate. We exhaustively lay down the theoretical formalism (dispersion relations, governing equations, and time-dependent wave solutions) for a broad suite of models. In all situations, we derive the steady state of an atmosphere, which is relevant to interpreting infrared phase and eclipse maps of exoplanetary atmospheres. We elucidate a pinching effect that confines the atmospheric structure to be near the equator. Our suite of analytical models may be used to develop decisively physical intuition and as a reference point for three-dimensional magnetohydrodynamic simulations of atmospheric circulation.

The Deep Blue Color of HD 189733b: Albedo Measurements with Hubble Space Telescope/Space Telescope Imaging Spectrograph at Visible Wavelengths

We present a secondary eclipse observation for the hot Jupiter HD 189733b across the wavelength range 290-570 nm made using the Space Telescope Imaging Spectrograph on the Hubble Space Telescope. We measure geometric albedos of Ag = 0.40 ± 0.12 across 290-450 nm and Ag < 0.12 across 450-570 nm at 1σ confidence. The albedo decrease toward longer wavelengths is also apparent when using six wavelength bins over the same wavelength range. This can be interpreted as evidence for optically thick reflective clouds on the dayside hemisphere with sodium absorption suppressing the scattered light signal beyond ~450 nm. Our best-fit albedo values imply that HD 189733b would appear a deep blue color at visible wavelengths.

Beamlet based direct aperture optimization for MERT using a photon MLC

PURPOSE A beamlet based direct aperture optimization (DAO) for modulated electron radiotherapy (MERT) using photon multileaf collimator (pMLC) shaped electron fields is developed and investigated. METHODS The Swiss Monte Carlo Plan (SMCP) allows the calculation of dose distributions for pMLC shaped electron beams. SMCP is interfaced with the Eclipse TPS (Varian Medical Systems, Palo Alto, CA) which can thus be included into the inverse treatment planning process for MERT. This process starts with the import of a CT-scan into Eclipse, the contouring of the target and the organs at risk (OARs), and the choice of the initial electron beam directions. For each electron beam, the number of apertures, their energy, and initial shape are defined. Furthermore, the DAO requires dose-volume constraints for the structures contoured. In order to carry out the DAO efficiently, the initial electron beams are divided into a grid of beamlets. For each of those, the dose distribution is precalculated using a modified electron beam model, resulting in a dose list for each beamlet and energy. Then the DAO is carried out, leading to a set of optimal apertures and corresponding weights. These optimal apertures are now converted into pMLC shaped segments and the dose calculation for each segment is performed. For these dose distributions, a weight optimization process is launched in order to minimize the differences between the dose distribution using the optimal apertures and the pMLC segments. Finally, a deliverable dose distribution for the MERT plan is obtained and loaded back into Eclipse for evaluation. For an idealized water phantom geometry, a MERT treatment plan is created and compared to the plan obtained using a previously developed forward planning strategy. Further, MERT treatment plans for three clinical situations (breast, chest wall, and parotid metastasis of a squamous cell skin carcinoma) are created using the developed inverse planning strategy. The MERT plans are compared to clinical standard treatment plans using photon beams and the differences between the optimal and the deliverable dose distributions are determined. RESULTS For the idealized water phantom geometry, the inversely optimized MERT plan is able to obtain the same PTV coverage, but with an improved OAR sparing compared to the forwardly optimized plan. Regarding the right-sided breast case, the MERT plan is able to reduce the lung volume receiving more than 30% of the prescribed dose and the mean lung dose compared to the standard plan. However, the standard plan leads to a better homogeneity within the CTV. The results for the left-sided thorax wall are similar but also the dose to the heart is reduced comparing MERT to the standard treatment plan. For the parotid case, MERT leads to lower doses for almost all OARs but to a less homogeneous dose distribution for the PTV when compared to a standard plan. For all cases, the weight optimization successfully minimized the differences between the optimal and the deliverable dose distribution. CONCLUSIONS A beamlet based DAO using multiple beam angles is implemented and successfully tested for an idealized water phantom geometry and clinical situations.

Forward treatment planning for modulated electron radiotherapy (MERT) employing Monte Carlo methods

PURPOSE This paper describes the development of a forward planning process for modulated electron radiotherapy (MERT). The approach is based on a previously developed electron beam model used to calculate dose distributions of electron beams shaped by a photon multi leaf collimator (pMLC). METHODS As the electron beam model has already been implemented into the Swiss Monte Carlo Plan environment, the Eclipse treatment planning system (Varian Medical Systems, Palo Alto, CA) can be included in the planning process for MERT. In a first step, CT data are imported into Eclipse and a pMLC shaped electron beam is set up. This initial electron beam is then divided into segments, with the electron energy in each segment chosen according to the distal depth of the planning target volume (PTV) in beam direction. In order to improve the homogeneity of the dose distribution in the PTV, a feathering process (Gaussian edge feathering) is launched, which results in a number of feathered segments. For each of these segments a dose calculation is performed employing the in-house developed electron beam model along with the macro Monte Carlo dose calculation algorithm. Finally, an automated weight optimization of all segments is carried out and the total dose distribution is read back into Eclipse for display and evaluation. One academic and two clinical situations are investigated for possible benefits of MERT treatment compared to standard treatments performed in our clinics and treatment with a bolus electron conformal (BolusECT) method. RESULTS The MERT treatment plan of the academic case was superior to the standard single segment electron treatment plan in terms of organs at risk (OAR) sparing. Further, a comparison between an unfeathered and a feathered MERT plan showed better PTV coverage and homogeneity for the feathered plan, with V95% increased from 90% to 96% and V107% decreased from 8% to nearly 0%. For a clinical breast boost irradiation, the MERT plan led to a similar homogeneity in the PTV compared to the standard treatment plan while the mean body dose was lower for the MERT plan. Regarding the second clinical case, a whole breast treatment, MERT resulted in a reduction of the lung volume receiving more than 45% of the prescribed dose when compared to the standard plan. On the other hand, the MERT plan leads to a larger low-dose lung volume and a degraded dose homogeneity in the PTV. For the clinical cases evaluated in this work, treatment plans using the BolusECT technique resulted in a more homogenous PTV and CTV coverage but higher doses to the OARs than the MERT plans. CONCLUSIONS MERT treatments were successfully planned for phantom and clinical cases, applying a newly developed intuitive and efficient forward planning strategy that employs a MC based electron beam model for pMLC shaped electron beams. It is shown that MERT can lead to a dose reduction in OARs compared to other methods. The process of feathering MERT segments results in an improvement of the dose homogeneity in the PTV.

Enabling knowledge creation through outsiders: towards a push model of open innovation

Open innovation is increasingly being adopted in business and describes a situation in which firms exchange ideas and knowledge with external participants, such as customers, suppliers, partner firms, and universities. This article extends the concept of open innovation with a push model of open innovation: knowledge is voluntarily created outside a firm by individuals and organisations who proceed to push knowledge into a firm’s open innovation project. For empirical analysis, we examine source code and newsgroup data on the Eclipse Development Platform. We find that outsiders invest as much in the firm’s project as the founding firm itself. Based on the insights from Eclipse, we develop four propositions: ‘preemptive generosity’ of a firm, ‘continuous commitment’, ‘adaptive governance structure’, and ‘low entry barrier’ are contexts that enable the push model of open innovation.

Who cares about my feature request?

Previous studies on issue tracking systems for open source software (OSS) focused mainly on requests for bug fixes. However, requests to add a new feature or an improvement to an OSS project are often also made in an issue tracking system. These inquiries are particularly important because they determine the further development of the software. This study examines if there is any difference between requests of the IBM developer community and other sources in terms of the likelihood of successful implementation. Our study consists of a case study of the issue tracking system BugZilla in the Eclipse integrated development environment (IDE). Our hypothesis, which was that feature requests from outsiders have less chances of being implemented, than feature requests from IBM developers, was confirmed.

Na 1 Nachlass Max Horkheimer, 493 - Korrespondenzen mit Mitarbeitern (u.a. Gerhard Brand, Ludwig von Friedeburg und Jürgen Habermas) aus dem Institut für Sozialforschung (p. V 193, 1 - 212)

Briefe zwischen Mitarbeitern des Instituts für Sozialforschung und Max Horkheimer, 1964-1973; 13 Briefe und Beilagen zwischen dem Verwaltungsleiter IfS Siegfried Geissler und Max Horkheimer, 1968-1973; 9 Briefe zwischen Klaus Körber (Institut für Sozialforschung) und Max Horkheimer, 1971-1973; 2 Briefe zwischen dem Professor Rudolf Gunzert und Max Horkheimer, 1972; 2 Briefe zwischen Dr. Joachim Bergmann (Institut für Sozialforschung) und Max Horkheimer, 1971; 2 Briefe zwischen dem Professor Gerhard Brandt und Max Horkheimer, 1971; 6 Briefe zwischen Herbert Ludwig (Institut für Sozialforschung) und Max Horkheimer, 1966-1967; 3 Briefe von Max Horkheimer an Professor Franz Böhm, 1966; Briefe zwischen den Mitarbeitern des Instituts für Sozialforschung und Max Horkheimer, 1955-1959; 4 Briefe von Jürgen Habermas an Max Horkheimer, Frankfurt, 1957-1959; 3 Briefe zwischen Christoph Oehler und Max Horkheimer, 1959; 13 Briefe zwischen Ludwig von Friedeburg und Max Horkheimer, 1955-1959; 1 Brief von Werner Wilkening an Max Horkheimer, 1958; 1 Brief von Gerhard Brandt an Max Horkheimer, 1958; 1 Brief von Max Horkheimer an den Dekan Helmut Viebrock, 1958; 2 Briefe von Egon Becker mit Helge Pross und Ludwig Friedeburg an Max Horkheimer, Frankfurt, 1958-1959; 2 Briefe von Helge Pross mit Egon Becker und Ludwig Friedeburg an Max Horkheimer, Frankfurt, 1958-1959; 1 Brief von Dieter Arenz an Max Horkheimer, Frankfurt, 1956; Briefe vom und an das Institut für Sozialforschung (Advisory Board of the Institute of Social Research), 1940-1947; Briefe und Briefentwürfe an und von Mitgliedern des Advisory Board betreffend die Zusendung von Max Horkheimer "Eclipse of Reason" und Karl August Wittvogel/Olga Lang, "Chinese Family and Society"; vom Institut für Sozialforschung, 1946-1947; 1 Brief von Edwin Borchard vom Institut für Sozialforschung, 1947; 1 Brief von Friedrich Pollock an Alfred E. Cohn, Los Angeles, 1947; 1 Brief von Friedrich Pollock an Stephan Duggan, Los Angeles, 1947; 2 Briefe zwischen Lloyd K. Garrison und Friedrich. Pollock, 1947; 1 Brief von Friedrich Pollock an Calvin B. Hoover, Los Angeles, 1947; 1 Brief von Friedrich Pollock an Philip C. Jessup, Los Angeles, 1947; 1 Brief von Friedrich Pollock an Wesley C. Mitchell, Los Angeles, 1947; 1 Brief von Friedrich Pollock an William A. Neilson, Los Angeles, 1947; 1 Brief von Friedrich Pollock an Frederick M. Padelford, Los Angeles, 1947; 1 Brief von Friedrich Pollock an Thorsten Sellin, Los Angeles, 1947; 3 Briefe zwischen John Whyte und Friedrich Pollock, 1947; 2 Briefe zwischen Louis Wirth und Friedrich Pollock, 1947; 1 Brief von Friedrich Pollock an Howard Woolston, Los Angeles, 1947; 1 Brief von George H. Sabine an das Institut für Sozialforschung, Ithaca, New York, 1946; Briefe und Briefentwürfe an und von Mitgliedern des Advisory Board betreffend den Druck eines neuen Briefkopfs des Instituts, 1940; 1 Brief von Leo Löwenthal, Pacific Palisades an Margot von Mendelssohn, 1942; 1 Brief von Leo Löwenthal an Margot von Mendelssohn, Pacific Palisades, 1942; 1 Brief von Max Horkheimer an K. Pilser, 1942; 2 Briefe zwischen Charles A. Beard und Max Horkheimer, 1940; 2 Briefe zwischen Edwin M. Borchard und Max Horkheimer, 1940; 3 Briefe zwischen Henry Sloane Coffin und Max Horkheimer, 1940; 2 Briefe zwischen Morris R. Cohen und Max Horkheimer, 1940; 2 Briefe zwischen Alfred E. Cohn und Max Horkheimer, 1940; 2 Briefe zwischen Stephen Duggan und Max Horkheimer, 1940; 2 Briefe zwischen dem Soziologen Henry Pratt Fairchild und Max Horkheimer, 1940; 2 Briefe zwischen Sidney B. Fay und Max Horkheimer, 1940; 2 Briefe zwischen Lloyd K. Garrison und Max Horkheimer, 1940; 1 Brief von Max Horkheimer an Calvin B. Hoover, 1940; 2 Briefe zwischen Robert M. Hutchins und Max Horkheimer, 1940; 2 Briefe zwischen Philip C. Jessup und Max Horkheimer, 1940; 2 Briefe zwischen Lewis L. Lorwin und Max Horkheimer, 1940; 2 Briefe zwischen Robert S. Lynd und Max Horkheimer, 1940; 2 Briefe zwischen Robert M. MacIver und Max Horkheimer, 1940; 2 Briefe von Max Horkheimer an Charles H. McIlwain, 1940; 2 Briefe zwischen Charles E. Merriam und Max Horkheimer, 1940; 2 Briefe zwischen Wesley C. Mitchell und Max Horkheimer, 1940; 2 Briefe zwischen William A. Nielson und Max Horkheimer, 1940; 5 Briefe zwischen Howard W. Odum und Max Horkheimer, 1940; 3 Briefe zwischen Frederick M. Padelford und Max Horkheimer, 1940; 3 Briefe von Max Horkheimer an Max Radin, 1940; 2 Briefe zwischen George H. Sabine und Max Horkheimer, 1940; 2 Briefe zwischen Thorsten Sellin und Max Horkheimer, 1940; 2 Briefe zwischen James T. Shotwell und Max Horkheimer, 1940; 1 Brief von dem Soziologen Louis Wirth an Franz Neumann, Chicago, 1940; 1 Brief von Louis Wirth an Franz L. Neumann, Chicago, 1940; 3 Briefe zwischen Howard Woolston und Max Horkheimer, 1940;

EVALUATION OF THE EFFECTIVENESS OF ANISOTROPIC ANALYTICAL ALGORITHM IN FLATTENED AND FLATTENING-FILTER-FREE BEAMS FOR HIGH ENERGY LUNG DOSE DELIVERY USING THE RADIOLOGICAL PHYSICS CENTER LUNG PHANTOM

The effectiveness of the Anisotropic Analytical Algorithm (AAA) implemented in the Eclipse treatment planning system (TPS) was evaluated using theRadiologicalPhysicsCenteranthropomorphic lung phantom using both flattened and flattening-filter-free high energy beams. Radiation treatment plans were developed following the Radiation Therapy Oncology Group and theRadiologicalPhysicsCenterguidelines for lung treatment using Stereotactic Radiation Body Therapy. The tumor was covered such that at least 95% of Planning Target Volume (PTV) received 100% of the prescribed dose while ensuring that normal tissue constraints were followed as well. Calculated doses were exported from the Eclipse TPS and compared with the experimental data as measured using thermoluminescence detectors (TLD) and radiochromic films that were placed inside the phantom. The results demonstrate that the AAA superposition-convolution algorithm is able to calculate SBRT treatment plans with all clinically used photon beams in the range from 6 MV to 18 MV. The measured dose distribution showed a good agreement with the calculated distribution using clinically acceptable criteria of ±5% dose or 3mm distance to agreement. These results show that in a heterogeneous environment a 3D pencil beam superposition-convolution algorithms with Monte Carlo pre-calculated scatter kernels, such as AAA, are able to reliably calculate dose, accounting for increased lateral scattering due to the loss of electronic equilibrium in low density medium. The data for high energy plans (15 MV and 18 MV) showed very good tumor coverage in contrast to findings by other investigators for less sophisticated dose calculation algorithms, which demonstrated less than expected tumor doses and generally worse tumor coverage for high energy plans compared to 6MV plans. This demonstrates that the modern superposition-convolution AAA algorithm is a significant improvement over previous algorithms and is able to calculate doses accurately for SBRT treatment plans in the highly heterogeneous environment of the thorax for both lower (≤12 MV) and higher (greater than 12 MV) beam energies.

Volumetric Modulated Arc Therapy Evaluation with the Radiological Physics Center Head and Neck Phantom

Validation of treatment plan quality and dose calculation accuracy is essential for new radiotherapy techniques, including volumetric modulated arc therapy (VMAT). VMAT delivers intensity modulated radiotherapy treatments while simultaneously rotating the gantry, adding an additional level of complexity to both the dose calculation and delivery of VMAT treatments compared to static gantry IMRT. The purpose of this project was to compare two VMAT systems, Elekta VMAT and Varian RapidArc, to the current standard of care, IMRT, in terms of both treatment plan quality and dosimetric delivery accuracy using the Radiological Physics Center (RPC) head and neck (H&N) phantom. Clinically relevant treatment plans were created for the phantom using typical prescription and dose constraints for Elekta VMAT (planned with Pinnacle3 Smart Arc) and RapidArc and IMRT (both planned with Eclipse). The treatment plans were evaluated to determine if they were clinically comparable using several dosimetric criteria, including ability to meet dose objectives, hot spots, conformity index, and homogeneity index. The planned treatments were delivered to the phantom and absolute doses and relative dose distributions were measured with thermoluminescent dosimeters (TLDs) and radiochromic film, respectively. The measured and calculated doses of each treatment were compared to determine if they were clinically acceptable based upon RPC criteria of ±7% dose difference and 4 mm distance-to-agreement. Gamma analysis was used to assess dosimetric accuracy, as well. All treatment plans were able to meet the dosimetric objectives set by the RPC and had similar hot spots in the normal tissue. The Elekta VMAT plan was more homogenous but less conformal than the RapidArc and IMRT plans. When comparing the measured and calculated doses, all plans met the RPC ±7%/4 mm criteria. The percent of points passing the gamma analysis for each treatment delivery was acceptable. Treatment plan quality of the Elekta VMAT, RapidArc and IMRT treatments were comparable for consistent dose prescriptions and constraints. Additionally, the dosimetric accuracy of the Elekta VMAT and RapidArc treatments was verified to be within acceptable tolerances.

"Un español sin patria ninguna" : el idioma de los libros en tiempos de auge editorial

El auge editorial argentino iniciado en 1938 suele atribuirse al coyuntural eclipse de la industria española con motivo de la guerra y la primera posguerra civil, y a la presencia de empresarios peninsulares en las editoriales que dominarían el mercado: Losada, Emecé y Sudamericana. No obstante, también los intelectuales colaboraron en este proceso, no sólo como directores de colección, traductores o correctores, sino específicamente apuntalándolo con su producción ensayística. El objetivo de este trabajo es analizar una serie de ensayos, producidos entre fines de la década del 1920 y mediados de 1940, por intelectuales argentinos y españoles emigrados en Buenos Aires, en los que se articulan los tópicos de la unidad lingüística hispanoamericana y el desarrollo librero. Focalizaremos aquí aquellos aspectos en los que estos discursos sobre el llamado "problema de la lengua en América" revelan los fundamentos económicos de las creencias lingüístico-culturales que procuran instalar.

"Un español sin patria ninguna" : el idioma de los libros en tiempos de auge editorial

El auge editorial argentino iniciado en 1938 suele atribuirse al coyuntural eclipse de la industria española con motivo de la guerra y la primera posguerra civil, y a la presencia de empresarios peninsulares en las editoriales que dominarían el mercado: Losada, Emecé y Sudamericana. No obstante, también los intelectuales colaboraron en este proceso, no sólo como directores de colección, traductores o correctores, sino específicamente apuntalándolo con su producción ensayística. El objetivo de este trabajo es analizar una serie de ensayos, producidos entre fines de la década del 1920 y mediados de 1940, por intelectuales argentinos y españoles emigrados en Buenos Aires, en los que se articulan los tópicos de la unidad lingüística hispanoamericana y el desarrollo librero. Focalizaremos aquí aquellos aspectos en los que estos discursos sobre el llamado "problema de la lengua en América" revelan los fundamentos económicos de las creencias lingüístico-culturales que procuran instalar.

Coloquio Internacional Mito y Performance : De Grecia a la Modernidad (5 : 2009 : La Plata). Mito y performance

Tabla de contenidos: Apolo, el ejecutante / Richard P. Martin. Está descripto un eclipse en La Odisea? / Constantino Baikouzis, Marcelo O. Magnasco. Literatura y astronomía / Héctor Vucetich. A propósito del mito en Platón : Falsedad y verdad / María Isabel Santa Cruz. Os gêneros líricos e a filosofia na República platônica / Maria das Graças de Moraes Augusto. Eurípides y el espectáculo de violencia / María de Fátima Silva. El mito de Orfeo y el problema del lenguaje en Eurípides / Juan Tobías Napoli. Resonancias poéticas de Eco / Juan Lorenzo Lorenzo. Súplica, lamento y encomio : La performance del mito en Homero / Graciela Cristina Zecchin de Fasano. Art and politics n Euripides'Ion : The gigantomachy as spectacle and model of action / Lucia Athanassaki. Poesia e espetáculo no Filoctetes de Sófocles / Fernando Brandao dos Santos. La presencia del mito en la novela / Lourdes Rojas Alvarez. El espacio femenino en las Traquinias de Sófocles / Filomena Yoshie Hirata. Mito y performance en la tragedia de Séneca / Lía Galán. Mito y performance sobre la escena ática : Praxitea, Erecteo, sus hijas y la etiología de la autoctonía / Claude Calame. O heói atleta : Mito e religiao nos jogos helênicos / Fábio de Souza Lessa. Las Agrionias y el mito de las Miníades. Razones de un ritual / Alberto Bernabé. Performing and re-performing Helen : Stesichorus' Palinode / Ewen Bowie.

"Un español sin patria ninguna" : el idioma de los libros en tiempos de auge editorial

El auge editorial argentino iniciado en 1938 suele atribuirse al coyuntural eclipse de la industria española con motivo de la guerra y la primera posguerra civil, y a la presencia de empresarios peninsulares en las editoriales que dominarían el mercado: Losada, Emecé y Sudamericana. No obstante, también los intelectuales colaboraron en este proceso, no sólo como directores de colección, traductores o correctores, sino específicamente apuntalándolo con su producción ensayística. El objetivo de este trabajo es analizar una serie de ensayos, producidos entre fines de la década del 1920 y mediados de 1940, por intelectuales argentinos y españoles emigrados en Buenos Aires, en los que se articulan los tópicos de la unidad lingüística hispanoamericana y el desarrollo librero. Focalizaremos aquí aquellos aspectos en los que estos discursos sobre el llamado "problema de la lengua en América" revelan los fundamentos económicos de las creencias lingüístico-culturales que procuran instalar.

Characteristics, home ranges and population estimates of narwhals (Monodon monoceros) around Baffin Island

Twenty-one narwhals tagged in 2003 and 2004 in Admiralty Inlet showed a different summer distributional pattern than previous narwhal-tracking studies from Somerset Island, Eclipse Sound and Melville Bay. The migration of the narwhals tracked from Admiralty Inlet moved out through Lancaster Sound 15 days earlier (P <0.0001) than the narwhals summering around Eclipse Sound, whereas the Admiralty Inlet narwhals reached the mouths of Eclipse Sound 18 days later (P <0.0001) than the Eclipse Sound summering population. The winter range of the Admiralty Inlet narwhals overlapped with the winter range of narwhals from Melville Bay and Eclipse Sound in central southern Baffin Bay and Northern Davis Strait, but not with the winter range of narwhals from Somerset Island that wintered further north. Distribution size of range, and population size did not appear to be related. An example of considerable year to year variation between area of summer and winter distribution in the 2 years was believed to be related to the sample size and number of pods of whales tagged, rather than to differences in sex or age classes.