1,181 research outputs found
A peculiar cluster of microearthquakes on the eastern flank of Katla volcano, southern Iceland
No full textA peculiar cluster of seismicity near the tip of Sandfellsjokull on the eastern flank of Katla volcano in southern Iceland has been analyzed in detail using data from a temporary seismic network. A total of 300 events were detected between July 2011 and August 2013, most of them from a swarm between December 4th and 12th, 2011. The sparser permanent network detected a small fraction of these events, but also a larger swarm in November 2010. When seismic activity started in this area is uncertain because of changes in the detection capability of the network over time. The events are of low magnitude (-0.5 < ML < 0.5) and the b-value of their magnitude distribution is high (1.6 +/- 0.1). Based on their frequency content (4-25 Hz) and clear P and S arrivals, the events are classified as volcano-tectonic. Two multiplets probably with different source mechanism are identified in their population. The events locate at approximately 3.5 km depth. Most of them are tightly clustered according to double difference relative locations in a volume that is only about 400 m in diameter in all directions. Several events are scattered up to 800 m beneath this volume. There is some suggestion of elongate structure in the cluster with a NNE/SSW strike and a dip of 60 degrees. We argue that these events cannot be due to a glacial or a broad tectonic process. Possibly, a localized source of fluid pressure, e.g., a small magma body at depth may be the source of these events
Ari naiz y ari dut
No full textSignificaciones del verbo "ari" en sus dos conjugaciones con "izan" y "ukan". Sugiere sustituír algunas locuciones incorrectas por "ari"Meanings of the verb "ari " in both its conjugations with "izan" and "ukan". The author suggests using some wrong expressions by "ari
Long-period seismic events with strikingly regular temporal patterns on Katla volcano's south flank (Iceland)
No full textKatla is a threatening volcano in Iceland, partly covered by the Mýrdalsjökull ice cap. The volcano has a large caldera with several active geothermal areas. A peculiar cluster of long-period seismic events started on Katla's south flank in July 2011, during an unrest episode in the caldera that culminated in a glacier outburst. The seismic events were tightly clustered at shallow depth in the Gvendarfell area, 4 km south of the caldera, under a small glacier stream at the southern margin of Mýrdalsjökull. No seismic events were known to have occurred in this area before. The most striking feature of this seismic cluster is its temporal pattern, characterized by regular intervals between repeating seismic events, modulated by a seasonal variation. Remarkable is also the stability of both the time and waveform features over a long time period, around 3.5 years. We have not found any comparable examples in the literature. Both volcanic and glacial processes can produce similar waveforms and therefore have to be considered as potential seismic sources. Discerning between these two causes is critical for monitoring glacier-clad volcanoes and has been controversial at Katla. For this new seismic cluster on the south flank, we regard volcano-related processes as more likely than glacial ones for the following reasons: 1) the seismic activity started during an unrest episode involving sudden melting of the glacier and a jökulhlaup; 2) the glacier stream is small and stagnant; 3) the seismicity remains regular and stable for years; 4) there is no apparent correlation with short-term weather changes, such as rainstorms. We suggest that a small, shallow hydrothermal system was activated on Katla's south flank in 2011, either by a minor magmatic injection or by changes of permeability in a local crack system
Uma proposta de ensino de literatura a partir da obra do escritor alagoano Ari Denisson
No full textThis research is based on a qualitative investigation, of the action research type, which suggests that literature classes should study the life and work of the author Ari Denisson, a poet and short story writer from Maceió, with the aim of valuing talents from Alagoas and encouraging a taste for reading and literary production. The actions of this project took place in a public school in a first-year high school class in 2024 and focused on the poetic work “baroque.doc” and the narrative work “Contos Periféricos”. A six-hour teaching sequence culminated in the author's visit to the school and a round of questions from the students. The interview was preceded by analyses of the selected texts and a presentation of the author's biography. The expected result is a way of rescuing the culture of Alagoas and Maceió and a greater appreciation of literature in Portuguese language classes. The authors who are references for this research range from Cosson, Boal, Freire, Rojo, to Antunes, among others.A presente pesquisa baseia-se em uma investigação de cunho qualitativo, do tipo pesquisa-ação que sugere para as aulas de literatura o estudo da vida e obra do autor Ari Denisson, poeta e contista maceioense, no intuito de valorizar os talentos alagoanos e incentivar o gosto pela leitura e produção literária. As ações desse projeto se deram em uma escola pública numa turma do primeiro ano do ensino médio no ano de 2024 e focaram na obra poética “baroque.doc” e na obra narrativa “Contos Periféricos”. Uma sequência didática de seis horas-aula teve como culminância a visita do autor na escola e uma rodada de perguntas dos alunos. A entrevista foi precedida por análises dos textos selecionados e apresentação da biografia do autor. Espera-se como resultado uma forma de resgate da cultura alagoana e maceioense e uma maior valorização da literatura dentro das aulas de língua portuguesa. Os autores que são referências para esta pesquisa vão desde Cosson, Boal, passando por Freire, Rojo, até Antunes, dentre outros
The Afterlife of Ari Nohem
No full textThis chapter traces the circulation of Ari Nohem in manuscript, from its composition through its first appearance in print. The different stages in the reception of Ari Nohem in manuscript offer an alternative history of Kabbalah in the seventeenth and eighteenth centuries, one that has largely been told through the histories of Sabbatianism and Hasidism. The manuscript transmission of Ari Nohem was typical rather than aberrant for texts written by early modern Jewish intellectuals on a variety of subjects: polemical writings on Christianity, esoteric kabbalistic treatises, and epistolary campaigns against the mystical messiah Sabbatai Zevi and his followers. The evidence of these manuscripts, combined with repeated citation of and allusion to Ari Nohem in letters, diaries, treatises, responsa, and compendia composed between 1639 and 1840, indicate that Jews and Christians continued to read Modena's text in nearly every generation between the death of the author and the printing of his book.</p
Health consultation, Ari-Zonolite (aka Buster's School of Street Rods facility), Glendale, Maricopa County, Arizona
No full textabstract: This report evaluates the potential exposure pathways associated with vermiculite concentrate processing activities at the Ari-Zonolite facility. The site is located in the near downtown area of Glendale, approximately ½ mile from the city hall, downtown shops, and other buildings. The former Ari-Zonolite facility received vermiculite from the Libby, Montana, mine. From 1951 to 1964, the site was leased the site to the Ari-Zonolite Company. Following the removal of the vermiculite concentrate processing equipment in 1964, several businesses have occupied the site. None of these businesses were involved in vermiculite processing activities. The last occupant of the former vermiculite processing building was an automotive restoration business, which vacated the site in 2002.Under cooperative agreement with the Agency for Toxic Substances and Disease Registry, U.S. Department of Health and Human Services.Includes bibliographical references (p. 17-19)
Tallgrass prairie soil fungal communities are resilient to climate change
No full textClimate models for central United States predict increasing temperatures and greater variability in precipitation. Combined, these shifts in environmental conditions impact many ecosystem properties and services. Long‐term climate change experiments, such as the Rainfall Manipulation Plots (RaMPs), can be used to address soil community responses to simultaneous manipulation of temperature and temporal variability in precipitation. The RaMPs experiment is located in a native tallgrass prairie at the Konza Prairie Biological Station and has been operational since 1998 providing the potential to address responses to long‐term environmental manipulations. To test whether community composition, richness, or diversity respond to environmental change, more than 40,000 fungal amplicons were analyzed from soil samples collected in 2006. The data suggest that soil fungal communities are compositionally resilient to predicted environmental change. This is the case both for the community composition overall as inferred from ordination analyses as well as analyses of variance for each of the most common Operational Taxonomic Units (OTUs). However, while this study suggests compositional resilience, further studies are required to address functional attributes of these communities and their responses to environmental manipulations
Improved hydrogeophysical characterization using joint inversion of cross-hole electrical resistance and ground-penetrating radar traveltime data.
No full textAppropriate regularizations of geophysical inverse problems and joint inversion of different data types improve geophysical models and increase their usefulness in hydrogeological studies. We have developed an efficient method to calculate stochastic regularization operators for given geostatistical models. The method, which combines circulant embedding and the diagonalization theorem of circulant matrices, is applicable for stationary geostatistical models when the grid discretization, in each spatial direction, is uniform in the volume of interest. We also used a structural approach to jointly invert cross-hole electrical resistance and ground-penetrating radar traveltime data in three dimensions. The two models are coupled by assuming, at all points, that the cross product of the gradients of the two models is zero. No petrophysical relationship between electrical conductivity and relative permittivity is assumed but is instead obtained as a by-product of the inversion. The approach has been applied to data collected in a U.K. sandstone aquifer in order to improve characterization of the vadose zone hydrostratigraphy. By analyzing scatterplots of electrical conductivity versus relative permittivity together with petrophysical models a zonation could be obtained with corresponding estimates of the electrical formation factor, the water content, and the effective grain radius of the sediments. The approach provides greater insight into the hydrogeological characteristics of the subsurface than by using conventional geophysical inversion methods
Septate endophyte colonization and host responses of grasses and forbs native to a tallgrass prairie
No full textNative tallgrass prairies support distinct dark septate endophyte (DSE) communities exemplified by periconia macrospinosa and Microdochium sp. that were recently identified as common root symbionts in this
system. Since these DSE fungi were repeatedly isolated from grasses and forbs, we aimed to test their abilities to
colonize different hosts. One Microdochium and three Periconia strains were screened for colonization and growth responses using five native grasses and six forbs
in an in vitro system. Previously published data for an additional grass (Andropogon gerardii) were included and reanalyzed. Presence of indicative inter- and intracellular structures (melanized hyphae, microsclerotia, and chlamydospores)
demonstrated that all plant species were colonized by the DSE isolates albeit to varying degrees. Microscopic observations suggested that, compared to forbs, grasses were colonized to a greater degree in vitro.
Host biomass responses varied among the host species. In broad comparisons, more grass species than forbs tended to respond positively to colonization, whereas more forb species tended to be non-responsive. Based on the suspected differences
in the levels of colonization, we predicted that tallgrass prairie grasses would support greater DSE colonization than forbs in the field. A survey of field-collected roots from 15
native species supported this hypothesis. Our study supports the “broad host range” of DSE fungi, although the differences
in the rates of colonization in the laboratory and in the field suggest a greater compatibility between grasses and DSE
fungi. Furthermore, host responses to DSE range from mutualism to parasitism, suggesting a genotype-level interplay
between the fungi and their hosts that determines the outcome of this symbiosis
Three essays on stock recommendations:
No full textThis dissertation studies stock recommendations made by columnists and financial analysts. The first essay examines the value and profitability of columnist recommendations published in the Business Week, Forbes and Fortune magazines. Empirical results show that columnist recommendations are not profitable in the short- or long-run controlling for market risk, book-to-market, size and momentum effects. The second essay examines the relation between the value of analysts’ recommendations and corporate research and development (R&D) investments. Univariate, calendar-time portfolio and cross-sectional analyses controlling for risk, business complexity, earnings value-relevance, analyst coverage, institutional ownership and bid-ask spread indicate the value of analysts’ recommendations to be significantly more valuable for firms that are more intensely engaged in R&D investments. The final essay, using stock recommendations, examines Regulation FD’s impact on corporate practice of earnings-related selective disclosure to financial analysts. The comparative analysis of the association between analysts’ revisions and subsequent earnings surprises, in the pre- and post- Regulation FD periods reveals a significant reduction in analysts’ earnings-related private information in the post-Regulation FD period.Ph.D.Includes bibliographical references (p. 130-137)by Ari Yezege
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