De esclavizados a comuneros en la cuenca aurífera del río Santiago - río Cayapas (Esmeraldas). Etnicidad negra en construcción en Ecuador Siglos XVIII-XIX

La presente investigación muestra el proceso de construcción de las sociedades negras de la cuenca del río Santiago, que se inicia con la llegada de esclavizados de las minas neogranadinas, en el siglo XVIII, con el fin de abrir una nueva frontera minera y prestar su contingente en los proyectos viales ideados por las autoridades para unir la Sierra con la Costa. El contexto peculiar de la región de Esmeraldas, de carácter marginal, caracterizado por la condición libre de la población negra, junto a un tipo de esclavitud particular en la que no predominaron las formas coercitivas, permitió a los esclavos, a partir de las cuadrillas, desplegar una serie de dispositivos efectivos y tomar posesión de las minas y sus espacios aledaños, dando lugar a la conformación de sociedades domésticas fortalecidas por lazos de parentesco y de solidaridad. Con la fase independentista, las sociedades esclavizadas del distrito minero van a participar a favor de la causa insurgente, motivados por el interés de continuar con su proyecto étnico de conformación social e identidades colectivas en medio de la libertad y legitimado por el nuevo Estado republicano. Con este interés se enrolaron como soldados de las fuerzas insurgentes, actuaron como chasquis y espías en los caminos, y generaron rumores entre la población, causando estragos a las fuerzas realistas. Esta dinámica de identidad y resistencia negra continuó en la república cuando las sociedades negras, en su lucha por el territorio, autonomía y libertad, frente a la intención del Estado nacional de integrar a los sectores excluidos mediante la ley de abolición de la esclavitud, se automanumitieron. Un acto de franco rechazo a una política de los sectores dominantes que, desde la Colonia, marcaron la presencia de fronteras sociales y culturales que los marginó y negó toda posibilidad de existencia digna. Para la segunda mitad del siglo XIX, frente a un nuevo escenario caracterizado por la presencia de empresas extranjeras, que iniciaron formas laborales represivas y usurpación de las tierras, la población liberta se conformó como comunidad del río Santiago y emprendió una nueva lucha, la compra del territorio, como una forma de legitimar sus sociedades. Más tarde y frente al permanente ambiente de agresión, debieron venderlas a los extranjeros, pero antes negociaron su vinculación laboral y su permanencia y de las futuras generaciones, un recurso que les permitió continuar ejerciendo su territorialidad y defendiendo su forma de vida en libertad.

El saber de la escolarización neoliberal en el discurso del cambio educativo del Gobierno de Sixto Durán Ballén: período 1992-1996

El tema de investigación«El saber de la escolarización neoliberal en el discurso del cambio educativo del Gobierno de Sixto Durán Ballén», Período: 1992-1996,tiene como objetivo principal identificar los enunciados de la escolarización neoliberal y conocer su impacto en la realidad educativa ecuatoriana. El tema tiene como contexto históricola transición del Ecuador, desde una fase del capitalismo dominado por el Estado Nacional, a otra fase liderada por el sistema financiero internacional –representado por el FMI y el BM- y, las empresas transnacionales. La situación caótica en que se encontraba el Ecuador en los años 80 permitió la puesta en marcha de los programas de Ajuste Estructural que consistió en una serie de medidas necesarias para lograr dos propósitos: uno, la apertura de la economía al mercado internacional; y dos, la garantía legal y económica del pago de la deuda externa. El Gobierno de Sixto Durán Ballén continuó con el Programa de Ajuste Estructural al intentar «modernizar» las instituciones públicas y privilegiar el pago de la deuda externa, loque significó desatender a educación, salud y empleo y ahondar las desigualdades sociales. En el caso de la educación ecuatoriana el período de Sixto Durán Ballén se caracterizó por profundizar las tendencias precedentes con respecto a la desinversión y desinstitucionalización del sector. Los bajos recursos limitaron el acceso y la calidadeducativa reduciéndose incluso las metas fijadas en el «Programa Educación Para Todos». Los maestros también sufrieron el deterioro de sus condiciones de vida y de trabajo lo que conllevó una enorme conflictividad en el sector. La desatención del Estado con la educación estimula a otros sectores a ofrecer servicios educativos y crece la educación privada cuantitativa y cualitativamente, epro, se amplían las desigualdades con la educación pública que daba cobertura a los sectores pobres. Adicionalmente, se evidencia la pérdida de rectoría de la política educativa del Ministerio de Educación cuando permite que el BM y el BID dirijanlos programas EB/PRODEC y PROMECEB. En definitiva, la investigación muestra cómo el carácter globalizador de la escolarización neoliberal va modelando no sólo la dimensión económica, políticay cultural de la región latinoamericana, también en el Ecuador se inserta en programas educativos específicos imprimiendo en ellos medidas de cuasi-mercado en los sectores más pobres.

La agenda educativa en el período liberal-radical 1895-1912

Este libro estudia la agenda educativa del liberalismo-radical que gobernó el Ecuador entre 1895 y 1912, luego de la Revolución liberal. Procura responder algunos interrogantes en torno a los temas de educación en la agenda pública de los dirigentes políticos de esa tendencia, al tiempo que busca desvelar lo que lograron ejecutar y aquello que quedó como asignatura pendiente. Su propósito también es revisar si dicha agenda constituyó una ruptura con lo que hasta ese momento se había realizado en cuanto a instrucción pública primaria, en general, y de las mujeres, en particular, o si continuó con la lógica de los gobiernos anteriores respecto al fortalecimiento del Estado y la ampliación de su control hacia periferias que aún se encontraban fuera de su poder en el período analizado. La autora, mediante el análisis de los documentos de la época, demuestra que el proyecto de instrucción pública laica y gratuita del liberalismo-radical tuvo demoras y dificultades para concretarse en el caso de los varones, y no llegó a ejecutarse en lo que se refiere a la formación de las niñas, pese a los esfuerzos que en ello empeñaron.

A review of the theoretical basis for bulk mass flux convective parameterization

Most parameterizations for precipitating convection in use today are bulk schemes, in which an ensemble of cumulus elements with different properties is modelled as a single, representative entraining-detraining plume. We review the underpinning mathematical model for such parameterizations, in particular by comparing it with spectral models in which elements are not combined into the representative plume. The chief merit of a bulk model is that the representative plume can be described by an equation set with the same structure as that which describes each element in a spectral model. The equivalence relies on an ansatz for detrained condensate introduced by Yanai et al. (1973) and on a simplified microphysics. There are also conceptual differences in the closure of bulk and spectral parameterizations. In particular, we show that the convective quasi-equilibrium closure of Arakawa and Schubert (1974) for spectral parameterizations cannot be carried over to a bulk parameterization in a straightforward way. Quasi-equilibrium of the cloud work function assumes a timescale separation between a slow forcing process and a rapid convective response. But, for the natural bulk analogue to the cloud-work function (the dilute CAPE), the relevant forcing is characterised by a different timescale, and so its quasi-equilibrium entails a different physical constraint. Closures of bulk parameterization that use the non-entraining parcel value of CAPE do not suffer from this timescale issue. However, the Yanai et al. (1973) ansatz must be invoked as a necessary ingredient of those closures.

The expected imprint of flux rope geometry on suprathermal electrons in magnetic clouds

Magnetic clouds are a subset of interplanetary coronal mass ejections characterized by a smooth rotation in the magnetic field direction, which is interpreted as a signature of a magnetic flux rope. Suprathermal electron observations indicate that one or both ends of a magnetic cloud typically remain connected to the Sun as it moves out through the heliosphere. With distance from the axis of the flux rope, out toward its edge, the magnetic field winds more tightly about the axis and electrons must traverse longer magnetic field lines to reach the same heliocentric distance. This increased time of flight allows greater pitch-angle scattering to occur, meaning suprathermal electron pitch-angle distributions should be systematically broader at the edges of the flux rope than at the axis. We model this effect with an analytical magnetic flux rope model and a numerical scheme for suprathermal electron pitch-angle scattering and find that the signature of a magnetic flux rope should be observable with the typical pitch-angle resolution of suprathermal electron data provided ACE's SWEPAM instrument. Evidence of this signature in the observations, however, is weak, possibly because reconnection of magnetic fields within the flux rope acts to intermix flux tubes.

Excess open solar magnetic flux from satellite data: 1. Analysis of the third perihelion Ulysses pass

We use the third perihelion pass by the Ulysses spacecraft to illustrate and investigate the “flux excess” effect, whereby open solar flux estimates from spacecraft increase with increasing heliocentric distance. We analyze the potential effects of small-scale structure in the heliospheric field (giving fluctuations in the radial component on timescales smaller than 1 h) and kinematic time-of-flight effects of longitudinal structure in the solar wind flow. We show that the flux excess is explained by neither very small-scale structure (timescales < 1 h) nor by the kinematic “bunching effect” on spacecraft sampling. The observed flux excesses is, however, well explained by the kinematic effect of larger-scale (>1 day) solar wind speed variations on the frozen-in heliospheric field. We show that averaging over an interval T (that is long enough to eliminate structure originating in the heliosphere yet small enough to avoid cancelling opposite polarity radial field that originates from genuine sector structure in the coronal source field) is only an approximately valid way of allowing for these effects and does not adequately explain or account for differences between the streamer belt and the polar coronal holes.

Excess open solar magnetic flux from satellite data: 2. A survey of kinematic effects

We investigate the “flux excess” effect, whereby open solar flux estimates from spacecraft increase with increasing heliocentric distance. We analyze the kinematic effect on these open solar flux estimates of large-scale longitudinal structure in the solar wind flow, with particular emphasis on correcting estimates made using data from near-Earth satellites. We show that scatter, but no net bias, is introduced by the kinematic “bunching effect” on sampling and that this is true for both compression and rarefaction regions. The observed flux excesses, as a function of heliocentric distance, are shown to be consistent with open solar flux estimates from solar magnetograms made using the potential field source surface method and are well explained by the kinematic effect of solar wind speed variations on the frozen-in heliospheric field. Applying this kinematic correction to the Omni-2 interplanetary data set shows that the open solar flux at solar minimum fell from an annual mean of 3.82 × 1016 Wb in 1987 to close to half that value (1.98 × 1016 Wb) in 2007, making the fall in the minimum value over the last two solar cycles considerably faster than the rise inferred from geomagnetic activity observations over four solar cycles in the first half of the 20th century.

Conservation of open solar magnetic flux and the floor in the heliospheric magnetic field

The near-Earth heliospheric magnetic field intensity, |B|, exhibits a strong solar cycle variation, but returns to the same ``floor'' value each solar minimum. The current minimum, however, has seen |B| drop below previous minima, bringing in to question the existence of a floor, or at the very least requiring a re-assessment of its value. In this study we assume heliospheric flux consists of a constant open flux component and a time-varying contribution from CMEs. In this scenario, the true floor is |B| with zero CME contribution. Using observed CME rates over the solar cycle, we estimate the ``no-CME'' |B| floor at ~4.0 +/- 0.3 nT, lower than previous floor estimates and below |B| observed this solar minimum. We speculate that the drop in |B| observed this minimum may be due to a persistently lower CME rate than the previous minimum, though there are large uncertainties in the supporting observational data.

Reconciling the electron counterstreaming and dropout occurrence rates with the heliospheric flux budget

Counterstreaming electrons (CSEs) are treated as signatures of closed magnetic flux, i.e., loops connected to the Sun at both ends. However, CSEs at 1 AU likely fade as the apex of a closed loop passes beyond some distance R, owing to scattering of the sunward beam along its continually increasing path length. The remaining antisunward beam at 1 AU would then give a false signature of open flux. Subsequent opening of a loop at the Sun by interchange reconnection with an open field line would produce an electron dropout (ED) at 1 AU, as if two open field lines were reconnecting to completely disconnect from the Sun. Thus EDs can be signatures of interchange reconnection as well as the commonly attributed disconnection. We incorporate CSE fadeout into a model that matches time-varying closed flux from interplanetary coronal mass ejections (ICMEs) to the solar cycle variation in heliospheric flux. Using the observed occurrence rate of CSEs at solar maximum, the model estimates R ∼ 8–10 AU. Hence we demonstrate that EDs should be much rarer than CSEs at 1 AU, as EDs can only be detected when the juncture points of reconnected field lines lie sunward of the detector, whereas CSEs continue to be detected in the legs of all loops that have expanded beyond the detector, out to R. We also demonstrate that if closed flux added to the heliosphere by ICMEs is instead balanced by disconnection elsewhere, then ED occurrence at 1 AU would still be rare, contrary to earlier expectations.

Coronal mass ejections and magnetic flux buildup in the heliosphere

To test for magnetic flux buildup in the heliosphere from coronal mass ejections (CMEs), we simulate heliospheric flux as a constant background open flux with a time-varying interplanetary CME (ICME) contribution. As flux carried by ejecta can only contribute to the heliospheric flux budget while it remains closed, the ICME flux opening rate is an important factor. Two separate forms for the ICME flux opening rate are considered: (1) constant and (2) exponentially decaying with time. Coronagraph observations are used to determine the CME occurrence rates, while in situ observations are used to estimate the magnetic flux content of a typical ICME. Both static equilibrium and dynamic simulations, using the constant and exponential ICME flux opening models, require flux opening timescales of ∼50 days in order to match the observed doubling in the magnetic field intensity at 1 AU over the solar cycle. Such timescales are equivalent to a change in the ICME closed flux of only ∼7–12% between 1 and 5 AU, consistent with CSE signatures; no flux buildup results. The dynamic simulation yields a solar cycle flux variation with high variability that matches the overall variability of the observed magnetic field intensity remarkably well, including the double peak forming the Gnevyshev gap.

A kinematically distorted flux rope model for magnetic clouds

Constant-α force-free magnetic flux rope models have proven to be a valuable first step toward understanding the global context of in situ observations of magnetic clouds. However, cylindrical symmetry is necessarily assumed when using such models, and it is apparent from both observations and modeling that magnetic clouds have highly noncircular cross sections. A number of approaches have been adopted to relax the circular cross section approximation: frequently, the cross-sectional shape is allowed to take an arbitrarily chosen shape (usually elliptical), increasing the number of free parameters that are fit between data and model. While a better “fit” may be achieved in terms of reducing the mean square error between the model and observed magnetic field time series, it is not always clear that this translates to a more accurate reconstruction of the global structure of the magnetic cloud. We develop a new, noncircular cross section flux rope model that is constrained by observations of CMEs/ICMEs and knowledge of the physical processes acting on the magnetic cloud: The magnetic cloud is assumed to initially take the form of a force-free flux rope in the low corona but to be subsequently deformed by a combination of axis-centered self-expansion and heliocentric radial expansion. The resulting analytical solution is validated by fitting to artificial time series produced by numerical MHD simulations of magnetic clouds and shown to accurately reproduce the global structure.

Understanding electron heat flux signatures in the solar wind

Suprathermal electrons (E > 80 eV) carry heat flux away from the Sun. Processes controlling the heat flux are not well understood. To gain insight into these processes, we model heat flux as a linear dependence on two independent parameters: electron number flux and electron pitch angle anisotropy. Pitch angle anisotropy is further modeled as a linear dependence on two solar wind components: magnetic field strength and plasma density. These components show no correlation with number flux, reinforcing its independence from pitch angle anisotropy. Multiple linear regression applied to 2 years of Wind data shows good correspondence between modeled and observed heat flux and anisotropy. The results suggest that the interplay of solar wind parameters and electron number flux results in distinctive heat flux dropouts at heliospheric features like plasma sheets but that these parameters continuously modify heat flux. This is inconsistent with magnetic disconnection as the primary cause of heat flux dropouts. Analysis of fast and slow solar wind regimes separately shows that electron number flux and pitch angle anisotropy are equally correlated with heat flux in slow wind but that number flux is the dominant correlative in fast wind. Also, magnetic field strength correlates better with pitch angle anisotropy in slow wind than in fast wind. The energy dependence of the model fits suggests different scattering processes in fast and slow wind.

Transpolar voltage and polar cap flux during the substorm cycle and steady convection events

Transpolar voltages observed during traversals of the polar cap by the Defense Meteorological Satellite Program (DMSP) F-13 spacecraft during 2001 are analyzed using the expanding-contracting polar cap model of ionospheric convection. Each of the 10,216 passes is classified by its substorm phase or as a steady convection event (SCE) by inspection of the AE indices. For all phases, we detect a contribution to the transpolar voltage by reconnection in both the dayside magnetopause and in the crosstail current sheet. Detection of the IMF influence is 97% certain during quiet intervals and >99% certain during substorm/SCE growth phases but falls to 75% in substorm expansion phases: It is only 27% during SCEs. Detection of the influence of the nightside voltage is only 19% certain during growth phases, rising during expansion phases to a peak of 96% in recovery phases: During SCEs, it is >99%. The voltage during SCEs is dominated by the nightside, not the dayside, reconnection. On average, substorm expansion phases halt the growth phase rise in polar cap flux rather than reversing it. The main destruction of the excess open flux takes place during the 6- to 10-hour interval after the recovery phase (as seen in AE) and at a rate which is relatively independent of polar cap flux because the NENL has by then retreated to the far tail. The best estimate of the voltage associated with viscous-like transfer of closed field lines into the tail is around 10 kV.