Estanislao Zeballos y los incentivos para la naturalización de extranjeros: Perfil de un legislador que buscó comunicar identidad Micheletti, María Gabriela Hombre público polifacético, el rosarino Estanislao Severo Zeballos (1854-1923) dedicó su vida a bregar por el progreso de su patria, siendo uno de los aspectos destacados de su actuación el vinculado a su preocupación por propender a la colonización del país a través de la inmigración. Este artículo pretende indagar, en el marco de la labor desplegada por Zeballos como diputado nacional, acerca del rol que buscó desempeñar como comunicador de identidad al extranjero inmigrante, ya que no sólo se interesó por el aporte material que podía redituar la presencia de éste, sino que demostró una temprana toma de conciencia acerca de la necesidad de incorporarlo efectivamente a la nacionalidad argentina. Para ello, se manifestó a favor de aplicar una política de incentivos a la naturalización de los extranjeros: la tierra, la jubilación y el voto electoral se convirtieron así, en el pensamiento del legislador, en adecuados alicientes que harían al inmigrante atractiva la idea de optar por la ciudadanía argentina. El objetivo final y fundamental perseguido, al que la naturalización coadyuvaría, era el de lograr la nacionalización cultural de las crecientes masas inmigratorias, a fin de evitar la temida disolución de la identidad nacional.

Patterns of ethnic, linguistic, and geographic heterogeneity of palmar interdigital ridge counts in the Indian subcontinent Reddy, B. Mohan; Demarchi, Dario; Bharati, S.; Kumar, Vikrant; Crawford, Michael H. Published data on palmar interdigital ridge counts (a-b, b-c, and c-d) among 57 populations from the Indian subcontinent were analyzed with reference to ethnic, socioeconomic, linguistic, and geographic affiliations of the studied populations. The spatial autocorrelation analysis suggests significant correlation between dermatoglyphic and geographic distances. The congruence with the ethnic semblance of the groups is also apparent in the data, and, in fact, the multiresponse permutation procedure did suggest highly significant within-group homogeneity, confirming the biological validity of the social and ethnic criteria used in the analysis. The plots of populations on the first two principal components, accounting for 92% of the total variance, complement and support the results based on the other analyses, which show certain ethnic and geographic patterns. These findings can serve as baseline information for future studies on population variation in India, particularly studies based on molecular genetic markers, a trend that has already gained momentum.

Genetic structure and gene flow in Gran Chaco populations of Argentina: Evidence from Y-chromosome markers Demarchi, Dario; Mitchell, R. John The Gran Chaco region of central South America has been settled by humans for only the last 4,000-5,000 years. To investigate population structure and variation in this region's indigenous population, we scored males from tribes of the Argentinean part of the Gran Chaco (Pilagá, Wichí, and Toba, representing two major language groups, the Mataco and Guaycurú) for a number of Y-chromosome polymorphisms. The markers included eight microsatellites (DYS19, DYS390, DYS391, DYS392, DYS393, DYS437, DYS438, and DYS439) and the unique native American single nucleotide polymorphism, DYS199. Sixty males (77%) from the total sample carried the DYS199T chromosome, and these were the focus of the present analysis. Unlike most other native Americans, Gran Chaco males show a moderate level of diversity at the DYS19 locus but still less than that seen in non-native Americans. The FST value for Y-chromosome markers in Gran Chaco was 0.107, a value that is more than double that found for mtDNA haplogroups in the same tribes but is not particularly high compared with other Y-chromosome studies. Phylogenetic trees based on all eight microsatellites showed relatively poor correlation of the tribes with either geography or language, and this is possibly explained by their ecology. They are seasonal hunters living in small bands, and under such circumstances drift will be a powerful evolutionary force. An UPGMA tree based on five microsatellites (DYS19, DYS390, DYS391, DYS392, and DYS393), however, showed a more positive relationship, suggesting that DYS437, DYS438, and DYS439 may behave differently from the other microsatellites. No association was found between maternal and paternal lineage distributions. The time to the most recent common ancestor of the DYS 199T chromosome is calculated to lie between 13,000 and 26,000 years. This range is consistent with estimates from other Y-chromosome studies as well as with estimates from mtDNA and the archeology of the colonization of South America. We conclude that the male lineages present in the contemporary Gran Chaco population reflect the level of diversity found in South America and that the region's male founders did not carry a restricted gene pool.

Mitochondrial extracellular signal-regulated kinases 1/2 (ERK1/2) are modulated during brain development Alonso, Mariana; Melani, Mariana; Converso, Daniela Paola; Jaitovich, Ariel; Paz, Cristina del Valle; Carreras, Maria Cecilia; Medina, Jorge Horacio; Poderoso, Juan José Intracellular activation and trafficking of extracellular signal-regulated protein kinases (ERK) play a significant role in cell cycle progression, contributing to developmental brain activities. Additionally, mitochondria participate in cell signalling through energy-linked functions, redox metabolism and activation of pro- or anti-apoptotic proteins. The purpose of the present study was to analyze the presence of ERK1/2 in mitochondria during rat brain development. Immunoblotting, immune electron microscopy and activity assays demonstrated that ERK1/2 are present in fully active brain mitochondria at the outer membrane/intermembrane space fraction. Besides, it was observed that ERK1/2 translocation to brain mitochondria follows a developmental pattern which is maximal between E19-P2 stages and afterwards declines at P3, just before maximal translocation to nucleus, and up to adulthood. Most of mitochondrial ERK1/2 were active; upstream phospho-MAPK/ERK kinases (MEK1/2) were also detected in the brain organelles. Mitochondrial phospho-ERK1/2 increased at 1 μM hydrogen peroxide (H2O2) concentration, but it decreased at higher 50-100 μm H2O 2, almost disappearing after the organelles were maximally stimulated to produce H2O2 with antimycin. Our results suggest that developmental mitochondrial activation of ERK1/2 cascade contributes to its nuclear translocation effects, providing information about mitochondrial energetic and redox status to the proliferating/differentiating nuclear pathways.

Historia y complejidad. La Historia del Tiempo Presente Figallo, Beatriz Josefina; García, Josefa El campo historiográfico de la Historia del Tiempo Presente, con su discurso peculiar nos propone una alternativa científica de alta capacidad explicativa para entender las claves de la relación pasado-presente-futuro. El planteo de este artículo busca contribuir en la conceptualización de la historia protagonizada por las generaciones vivas de la Argentina y América Latina, mediante categorías de análisis que consideran los fenómenos de crisis, de incertidumbre de tiempo corto – el acontecimiento-, con una apuesta fuerte por la interdisciplinariedad y por la atención a lo político, valorando la información proporcionada por los testimonios orales, la literatura, la música y el cine que dan cuenta de las sociedades que los produjeron y las nuevas fuentes electrónicas. El paradigma de la complejidad posibilita pensar la historia del tiempo presente concibiendo a la realidad como una dificultad perpetua para ser explicada, abriéndose a un gran número de posibilidades de interpretación.

Roya de la soja: Cómo prepararse para enfrentar a esta amenaza Ploper, Leonardo Daniel; Gálvez, M. Roberto; Devani, Mario Rodolfo; González, Victoria; Zamorano, María Antonia; Lenis, Julián M.; Ledesma, Fernando Martín La roya "asiática" de la soja, causada por Phakopsora pachyrhizi, ya se encuentra presente en numerosas regiones del país, incluido el noroeste argentino (NOA).  Esta situación plantea un nuevo desafío para la producción local de soja, ya que se trata de una enfermedad conocida por haber provocado severos daños en lotes ubicados en varios continentes.  En virtud de su alto poder de dispersión y su gran potencial de daño, se deberá estar muy atento al progreso de esta patología en las regiones en donde ya fue detectada, así como de su posible aparición en los sitios en donde aún no fue encontrada.  En el caso del NOA, la confirmación de la presencia de esta grave enfermedad obliga a productores y técnicos a incluir en sus esquemas de manejo del cultivo prácticas tendientes a disminuir riesgos de la ocurrencia de costosas epifitias.  En el presente trabajo se presenta información sobre la presencia de la roya de la soja en el NOA y se proponen medidas tentativas de manejo de la enfermedad, considerando especialmente que aún se desconoce el impacto real que la misma pueda llegar a tener en los cultivos de soja de la región.

«Atal allur a catade»: recuperación figural de la Antigüedad en la Cantigas de Santa María de Alfonso el Sabio Disalvo, Santiago Anibal Existe un nexo figural o tipológico entre el evento histórico relatado en la Cantiga de Santa María 205 y un pasaje de la Estoria de España, ambas obras alfonsíes que no suelen estudiarse en relación. Este recurso, que es sólo una muestra de la rica utilización de la tipología en el cancionero, evidencia un propósito de recuperación y superación simbólica («alegórica») del pasado pagano en el contexto más amplio de textos alfonsíes, que incluye también al Setenario.; There is a figural or typological nexus between the historical event told in Cantigas de Santa María 205 and a fragment of the Estoria de España, both alphonsine works which are not usually studied in connection. This feature, which is only a sample of the rich use of typology in the cancionero, is an evidence of an intended symbolic («allegorical») recovery and overcoming of the pagan past, in the wider context of alphonsine texts, including also Setenario.

Control of citrus black spot on lemons with Amistar, Comet, and Flint, 2002/03. Fungicide and Nematicide Tests Fogliata, G. M.; Ploper, Leonardo Daniel; Canton, Norma Virginia; Galvez, M. R.; Muñoz, L. This experiment was conducted in a 6-yr old Lisbon lemon grove in Macomitas, Tucumán, Argentina.  Within a 4-application program, one or two strobilurin applications at different times were included in combination with Dithane or Caurifix, completing the program with the mixture Caurifix plus Dithane.  Treatments were arranged in a randomized complete block design with four replications.  Each plot consisted of three trees. Fungicide applications started at petal fall and continued every 4 weeks for 4 months.  The grower treatment was considered the chemical control standard.  Sprays were made with a conventional high volume sprayer fitted with a handgun, at a pressure of 500 psi using 25 L/tree.  The first important rains began in October after petal fall.  Favorable conditions for infection prevailed from petal fall (October) to December, with rainfall totaling 368 mm, maximum relative humidity over 90%, and average temperatures higher than 18 ºC.  Two evaluations of citrus black spot (CBS) were made when fruits were harvested for the fresh fruit export market (19 May 03 and 22 Jun 03).  Disease incidence was determined in fruits from the center tree of each plot.  A total of 2,000 fruits was evaluated for each treatment. CBS incidence is presented as the average of both harvests.  Environmental conditions favored CBS.  All treatments significantly reduced CBS incidence.  No differences in CBS incidence were detected among the 3 strobilurins in the treatments that included 2-strobilurin applications, and all of these treatments were more effective for CBS control than the grower treatment.  The 3 strobilurins performed differently  in the treatments where only one spray of  strobilurins was included. Comet was more effective than the grower treatment in 3 of the 4 treatments evaluated, in combination with Caurifix at 60 or 90 days after petal fall (apf) and in combination with Dithane at 90 days apf. Comet had  the same CBS incidence as the grower treatment when applied with Dithane at 60 days apf.  The Flint treatments varied according to the other fungicide included in the combination. The two Flint treatments where the fungicide was applied with Caurifix were more effective than the grower treatment. No difference was detected between applications made 60 or 90 days afp.  The mixture Flint-Dithane showed the same CBS incidence as the grower treatment at 60 or 90 days apf.  The performance of Amistar  varied according to the timing of the application; it was more effective than the grower treatment when applied at 60 days apf in combination with either Caurifix or Dithane.  When this fungicide was applied at 90 days apf, the CBS incidence was similar to the grower treatment, with either Caurifix or Dithane. These results indicate that a one application of strobilurins significantly decreases CBS incidence compared to the grower treatment, but that the performance is influenced by the timing of application and fungicide included in the mixture.

Ionospheric storm effects at the equatorial anomaly Mansilla, Gustavo Adolfo Ionospheric disturbances produced at the equatorial anomaly (EA) region during some geomagnetic storms were investigated using hourly NmF2 peak electron density of F2-layer values from stations located at equatorial and low geomagnetic latitudes. In general, increases (positive storm effects) or decreases (negative storm effects) of NmF2 (proportional to square of foF2 ionospheric critical frequency) in the nighttime hours were observed at equatorial latitudes in response to storms started during sunset hours. For the storm onset occurring during morning hours an intensification of the fountain effect was produced. For the storms starting in the nighttime hours no significant disturbances appeared at the crest regions in association with the initial positive or negative effects observed at the trough in the daytime. During the recovery phase in general significant delayed positive storm effects occurred mainly at low latitudes and a minor degree at equatorial latitudes. Possible physical mechanisms for controlling the morphology of the ionosphere during these events are considered.

Colapso estructural bajo cargas explosivas Luccioni, Bibiana Maria; Ambrosini, Ricardo Daniel; Danesi, Rodolfo Francisco Las estructuras civiles no son generalmente diseñadas para resistir cargas dinámicas de muy corta duración y gran amplitud como las generadas por explosiones e impacto. Hasta hace muy poco tiempo, la consideración de cargas explosivas debidas a un ataque terrorista se limitaba principalmente a estructuras tales como estructuras militares, centrales nucleares, embajadas, etc. En este trabajo se presenta la simulación del proceso de destrucción de estructuras de hormigón producido por la detonación de cargas explosivas. Dicho estudio se realiza mediante un hidrocódigo que considera la interacción fluido (aire)- estructura. Se describen en el trabajo los modelos materiales utilizados para el hormigón y mampostería.Dichos modelos incluyen la simulación del fenómeno de desintegración o fractura del material que permite eliminar al mismo del cálculo para simular erosión o discontinuidades producidas en el material por la carga explosiva. Se presentan, además, las distintas estrategias de calculo utilizadas en la simulación del proceso completo, desde la detonación del explosivo, hasta la caída del edificio.

The Toeplitz algebra on the Bergman space coincides with its commutator ideal Suarez, Fernando Daniel Let L^2-a be the Bergman space of the unit disk and T(L^2_a) be the Banach algebra generated by Toeplitz operators T_f , with f ∈ L∞. We prove that the closed bilateral ideal of T(L2a) generated by operators of the form T_fT_g − T_gT_f coincides with T(L^2_a).

Flea parasites of small mammals in the Monte Desert biome in Argentina with new host and locality records Lareschi, Marcela; Ojeda, Ricardo Alberto; Linardi, Pedro M. Fleas associated with small mammals from the Argentinean Monte Desert, were examined. The research was carried out in Ñacuñán Biosphere Reserve (34°02´S, 67°58´W), in the Chaqueña Biogeographic Subregion of the Neotropical Region. Mammal species trapped were as follows: Rodentia, Muridae, Sigmodontinae: Akodon molinae Contreras, 1968 (N = 44), Graomys griseoflavus (Waterhouse, 1837) (N = 15), Calomys musculinus (Thomas, 1913) (N = 12), and Eligmodontia typus F. Cuvier, 1837 (N = 7); Didelphiomorphia, Didelphidae, Mamorsinae: Thylamys pusillus (Desmarest, 1804) (N = 1). A total of 236 fleas were collected: Stephanocircidae, Craneopsyllinae: Craneopsylla minerva wolffhuegeli (Rothschild, 1909); Rhopalopsyllidae, Rhopalopsyllinae: Polygenis (Polygenis) bohlsi bohlsi (Wagner, 1901), Polygenis (Polygenis) platensis cisandinus (Jordan, 1939) and Polygenis (Neopolygenis) puelche Del Ponte, 1963; Rhopalopsyllidae, Parapsyllinae: Ectinorus (Ectinorus) barrerai Jordan, 1939. High values of total mean abundance (MA = 2.99) and total prevalence (P = 73.41%) were obtained. A. molinae (MA = 3.14; P = 93.18; flea specific richness S = 5; Shannon specific diversity index H = 1.25) and G. griseoflavus (MA = 6.40; P = 100%; S = 5; H = 0.76) showed the highest values of the infestation parameters. No fleas were collected from E. typus, possibly because of its habits. Fleas associated with T. pusillus are reported for the first time. Our collections extend the western limits of the distribution of both P. (N.) puelche and P. (P.) b. bohlsi. In addition, new host species are reported for every flea species and subspecies, and seven host-flea associations are mentioned for the first time.

Study of degenerate bifurcations in maps: A feedback systems approach D'amico, Edith Maria Belen; Moiola, Jorge Luis; Paolini, Eduardo Emilio The dynamical behavior of nonlinear maps undergoing degenerate period doubling or degenerate Hopf bifurcations is studied via a frequency-domain approach. The technique is based on a discrete-time feedback representation of the system and the application of the well-known engineering tools of harmonic balance to approximate the emerging solutions. More specifically, the results are a higher-order extension of the previous developments obtained by the authors for nondegenerate bifurcations. Two examples are included for illustration. Read More: http://www.worldscientific.com/doi/abs/10.1142/S0218127404010266

Regularidad con respecto a parámetros de las soluciones de problemas parabólicos abstractos semilineales Spies, Ruben Daniel Se determinan condiciones suficientes bajo las cuales la solucion z(t;q) de un problema parabólico abstracto semilineal de la forma d/dt z(t)=A(q)z(t) + F(q,t,z(t)) es derivable Fréchet con respecto al parámetro q. Se prueba que la derivada de Fréchet D_q z(t;q) es la solución de un problema de valores iniciales lineal no homogéneo en el espacio de estados Z.  Se provee una forma explícita para este problema de valores iniciales que constituye la llamada "ecuación de sensitividad" para la solución z(t;q).

El alimento, la cocina étnica, la gastronomía nacional. Elemento patrimonial y un referente de la identidad cultural. Torres, Graciela Felisa  En el artículo se analiza la cualidad de elemento patrimonial del alimento y el conjunto denominado cocina nacional.Para ello se define brevemente el concepto de Patrimonio en sus vertientes tangible e intangible.El alimento que se encuadraría enla esfera de lo intangible, se constituye en el eje del análisis y se establecen sus relaciones tanto con el Patrimonio en general como con el proceso de construcción de la identidad de un grupo social determinado. Se consideran algunos platos o comidas propias de la región Noroeste como ejemplos de referentes identitarios. 

Resistencias al orden formalizado por la Constitución de Mendoza de 1854 en el ámbito de la campaña Sanjurjo, Ines Elena El trabajo analiza la efectiva aplicación de los principios del moderno constitucionalismo en Mendoza luego de formalizado el orden liberal mediante la carta magna provincial de 1854. Busca averiguar, para el período de vigencia de esa constitución (1854-1895), si no obstante el proceso de complejización del aparato del Estado provincial y la política de afianzamiento de su potestad sobre el territorio, quedaron espacios que escaparon a ese poder, o se dieron prácticas resistentes a los principios en boga. Se ha puesto particular atención a las localidades de la campaña, que por las distancias o la poca accesibilidad, se estima eran poco proclives a los cambios y estaban menos expuestas al control estatal.; The work analyzes the effective application of the principles of the modern constitutionalism in Mendoza after it was formalized the liberal order by means of the Constitution of 1854. The investigation tries to quarrel if in the period of this constitution life (1854-1895), nevertheless the bigger complexity of the state mechanisms and the politics of strengthening the legal authority on the territory, there were spaces that escaped to this power, or practices resistant to the principles in vogue. The work has put on particular attention to the rural localities, which for the distances or small accessibility, is estimated they were less inclined to the changes and less exposed to the state control.

Assignment of Paternity in a Judicial Dispute Between Two Neighbor Holstein Dairy Farmers Liron, Juan Pedro; Ripoli, María Verónica; Peral Garcia, Pilar; Giovambattista, Guillermo DNA profiling was used as evidence to assign paternity in a dispute between two neighbors in a judicial case of undue appropriation of cattle offspring from five alleged Holstein sires. Five offspring were genotyped using ten genetic markers (nine microsatellites and the BOLA-DRB3 locus). The computer program CERVUS was used to estimate the LOD score values and the confidence of paternity assignments. The results presented here show that three out of five paternity cases were assigned at 95% of confidence to a single sire with a LOD score ranging from 2.53 to 3.55. A fourth male was assigned using its D value. Finally, all alleged sires were excluded from the paternity of the fifth offspring, probably due to the existence of an non-sampled male in the studied population. We concluded that the likelihood-based approach, included into CERVUS program, was a powerful tool in cattle kinship analysis when dealing with judicial dispute particularly when the dam's genotype was absent, allowing the assignments of paternity at 95% level of confidence in situations usually used by dairy and beef cattle producers in Argentine (e.g., multi-sire pasture mating).

Petrography and geochemistry of the Carapé Granitic Complex (Southeastern Uruguay) Bettucci Sanchez, Leda; Oyhantçabal, Pedro; Page, Stella; Ramos, Victor Alberto The southern sector of Uruguay was intruded by numerous granitic plutons during the Brasiliano Cycle. The granites and granodiorites of the Carapé Complex comprise a large part of the Neoproterozoic terrain exposed in southern Uruguay. Typological and age relationships show that the characteristic of the granitic rocks changed during the Brasiliano Cycle. Four groups of granitoids can be distinguished according to their emplacement. The first group corresponds to the Campanero Unit, interpreted as a pre-Brasiliano basement, which includes mainly preorogenic granites. The second group, Pan de Azúcar and related granitoids, includes synorogenic granites and granodiorites. The third granitoid group, Dos Hermanos Granite and related plutons, is classified as late- to postorogenic granites. Finally, the fourth group, consisting of the Águila Granite and related plutons, is represented by alkaline amphibole-biotite granites and are considered as post-collisional alkaline granites, which we assign to an extensional event associated with post-collisional slab-break off marking the end of the late Proterozoic Brasiliano orogenic cycle. Most of the granitic plutons in this area (2,300 km2) are relatively well exposed and have well-defined intrusive relationships with the metamorphic country-rocks. These granitic rocks are the result of successive magma pulses from similar magma chambers through the late Proterozoic to early Paleozoic times.

Variaciones geomagnéticas atribuídas a la corriente anillo ecuatorial en períodos de tormenta magnética, a partir de registros en observatorios simétricos en latitud geomagnética Van Zele, Maria Andrea Las variaciones del campo magnético terrestre registradas durante una tormenta geomagnética son la superposición de variaciones regulares y perturbaciones. Las primeras son debidas principalmente a corrientes en la alta atmósfera generadas por la acción dínamo de un sistema de vientos horizontales; las segundas a corrientes magnetosféricas e ionosféricas causadas por la transferencia de masa y energía del viento solar a la magnetosfera. Entre éstas últimas se destaca la corriente anillo ecuatorial, que circula hacia el oeste con simetría respecto del plano del ecuador geomagnético y en su vecindad; la variación geomagnética que produce ha sido tradicionalmente calculada suponiendo que tiene simetría cilíndrica alrededor del eje del dipolo geomagnético, extrapolándose por tanto que la corriente anillo ecuatorial tiene tal simetría cilíndrica. Los valores symH calculados (por minuto) por el Centro Mundial de Kyoto (Japón) pretenden expresar, con mayor definición temporal que los tradicionales índices Dst (horarios), las variaciones debidas a la corriente anillo ecuatorial. Ambos conjuntos forman sucesiones completas. En este trabajo se presenta un método que se basa en imponer una condición de simetría a la variación geomagnética que se atribuye a la corriente anillo ecuatorial: una misma variación negativa de la componente norte y variaciones opuestas de la componente vertical, a ambos lados del ecuador geomagnético. Para ello se utilizan la componente norte X y la vertical Z registradas durante tormentas geomagnéticas en pares de observatorios con latitud geomagnética conjugada y similar longitud. Los resultados permiten corroborar que la componente norte condicionada por la simetría ecuatorial depende del tiempo local (de la longitud de los observatorios), mostrando que esta variación no es independiente del ángulo acimutal alrededor del eje dipolar geomagnético (no tiene simetría cilíndrica alrededor de él). De la relación entre las componentes geomagnéticas norte y vertical que satisfacen la condición de simetría ecuatorial impuesta, se deduce que la corriente anillo ecuatorial no es la única que satisface tal condición, sino que los aportes de las variaciones debidas a las corriente de la magnetopausa, de la cola magnética, de la cuña auroral o las ionosféricas no pueden ser consideradas despreciables. El conjunto de los valores de la variación hallada con la condición de simetría respecto del plano ecuatorial no es completo.; The geomagnetic field variations recorded on the Earth during a geomagnetic storm are the superposition of both quiet and disturbed variations. The first ones are principally due to currents at the upper atmosphere generated by the dynamo action of a sys tem of horizontal wind. The second ones are due to ionospheric and magnetospheric currents caused by the mass and energy transfer of the solar wind to the magnetosphere. Among these last ones, the equatorial ring current drifts westward, with symmetry in relation with the geomagnetic equator, at 4-7 Re. It produces a geomagnetic variation that has been traditionally calculating assuming that it is symmetric around the dipole axis. The symH values calculated (each minute) by the WDC-C2 of Kyoto supposedly express, with better definition than the hourly Dst index the geomagnetic variations due to this equatorial ring current. This work presents a method based on the symmetrical condition imposed to the geomagnetic variations impute to the equatorial ring current: the same negative variation of the north X component and opposite variations of the vertical component, at both sides of the geomagnetic equator. The north X and the vertical Z components recorded during a geomagnetic storm, in pairs of observatories with conjugate geomagnetic latitude and similar longitude are used. The results verified that the conditioned X component (which is comparable with the indices) in not independent of the azimuthal angle around the dipole axis (depends on the local time). From the relation between X and Z conditioned components it is deduced that the equatorial ring current is not the only one satisfying the symmetry imposed, but variations due to the currents at the magnetopause, the magnetic tail, the auroral wedge or the ionospheric ones can not be ignored. The set of values of the conditioned variations by the equatorial symmetry is not complete.

Palinoestratigrafía y palinofacies de la Formación Lotena, Jurásico Medio de la Cuenca Neuquina, Argentina; Palynostratigraphy and palynofacies of the Lotena Formation, middle jurassic of the Neuquén basin, Argentina Martinez, Marcelo Adrian; Quattrocchio, Mirta Elena El análisis palinológico aplicado a muestras de afloramiento de la Formación Lotena (datos integrados del perfil Portada Covunco y registros previos de perfil arroyo Picún Leufú) permitió determinar 29 taxones de esporomorfos (esporas: 10 y granos de polen: 19) y 40 taxones de paleomicroplancton (prasinofíceas: 2, acritarcos: 15, dinoquistes: 23). Los resultados obtenidos a partir del análisis palinológico/palinofacial permiten sugerir un medio de depositación marino para ambas localidades, en posición distal (Portada Covunco) y proximal (arroyo Picún Leufú). Las palinofacies identificadas en el perfil Portada Covunco sugieren condiciones marinas variables desde posiciones distales (palinofacies A) hasta más proximales (palinofacies C). El registro de taxones de la Zona de Endoscriniumgaleritumreticulatum Klement, conjuntamente con la asociación de Gonyaulacystajurassica (Deflandre) Norris y Sarjeant-Scriniodiniumcrystallinum (Deflandre) Klement emend. Riding y Fensome permite sugerir que la Formación Lotena en el área de Portada Covunco, provincia de Neuquén, no sería más antigua que Caloviano Tardío.; The palynological analysis applied to outcrop samples from the Lotena Formation (integrated information from Portada Covunco section and previous data from Arroyo Picún Leufú section) allows to determine 29 sporomorph taxa (10 spores and 19 pollen grains) and 40 paleomicroplankton taxa (2 Prasinophyceae, 15 acritarchs and 23 dinocysts). A marine paleoenvironment with a variable proximal-distal trend is suggested for both sections on the basis of the palynological/palynofacial analysis. This trend varies from distal (Portada Covunco section) to proximal conditions (Arroyo Picún Leufú). Variable marine conditions from distal (palynofacies) to more proximal positions (palinofacies C) are suggested for the Portada Covunco section. The presence of the Endoscrinium galeritum reticulatum Klement Zone associated with Gonyaulacystajurassica (Deflandre) Norris and Sarjeant-Scriniodinium crystallinum (Deflandre) Klement emend. Riding and Fensome suggests an age not older than Late Callovian for the Lotena Formation at Portada Covunco, Neuquén province.