Towards a Real-Time Description of the Ionosphere: A Comparison between International Reference Ionosphere (IRI) and IRI Real-Time Assimilative Mapping (IRTAM) Models

This paper focuses on a detailed comparison, based on the F2-layer peak characteristics foF2 and hmF2, between the International Reference Ionosphere (IRI), which is a climatological empirical model of the terrestrial ionosphere, and the IRI Real-Time Assimilative Mapping (IRTAM) procedure, which is a real-time version of IRI based on data assimilation from a global network of ionosondes. To perform such a comparison, two different kinds of datasets have been considered: (1) foF2 and hmF2 as recorded by 40 ground-based ionosondes spread all over the world from 2000 to 2019; (2) foF2 and hmF2 from space-based COSMIC/FORMOSAT-3 radio occultation measurements recorded from 2006 to 2018. The aim of the paper is to understand whether and how much IRTAM improves IRI foF2 and hmF2 outputs for different locations and under different diurnal, seasonal, solar and magnetic activity conditions. The main outcomes of the study are: (1) when ionosonde observations are considered for validation, IRTAM significantly improves the IRI foF2 modeling both in accuracy and precision, while a slight improvement in the IRI hmF2 modeling is observed for specific locations and conditions; (2) when COSMIC observations are considered for validation, no noticeable improvement is observed from the IRTAM side for both foF2 and hmF2. Indeed, IRTAM can improve the IRI foF2 description only nearby the assimilated ionosonde locations, while the IRI hmF2 description is always more accurate and precise than IRTAM one.

Conceptual sounding of poems in the prose “Herds” by F. Aliyeva and “The Old Woman” by I. Turgenev

This article attempts to determine the attributes of the prose poem genre in the works “Herds” by Fazu Aliyeva and “The Old Woman” by Ivan Turgenev on the formal and emotional-semantic levels. Artistic parallels in creation of images by the authors of different generations are drawn. The subject of this research is the images of time, old woman and cliff and intertwinement of their destinies into a single time node. The object of this research is the lyrical narratives “Herds” by Fazu Aliyeva, “The Old Woman” and “How Fair, How Fresh Were the Roses…” by Ivan Turgenev. Special attention is given to analysis of the form and content of artistic images in “Herds”, in the context of prose poem “The Old Woman” by I. S. Turgenev, their conceptual and artistic peculiarities. The author also highlights the category of timely space in the narratives. The novelty of this research consists in drawing an artistic parallel between the lyrical narratives of Fazu Aliyeva and Ivan Turgenev regarding determination of the dominant and conceptual differences in creation of the image of time, description of the flow of time, connection between the past and the future, and interpretation of the theme of life and death. As a result, the identification of poetic beginning, philosophical comprehension and artistic presentation of the topic of life and death in the works of F. Aliyeva and I. Turgenev allows, upon similarity of sounding, tracing conceptual differences of the author's thought. Despite obvious similarity of underlying ideas, the aforementioned topic is described differently. In the works of F. Aliyeva, time is not confined, looks into the future, resembling in the succession of generations; with all the pain and losses, the image is life-affirming. In the works of I. Turgenev, the hero turns to the past, experiences the ultimate fear of death, everything stops in anticipation of the end of existence.

Quelques particularités dans l’expression de la détermination du nom. Comparaison entre cinq langues romanes

"Some Features in the Expression of the Noun Determination. Comparison Between Five Romance Languages. In this article we would like to compare the noun determination in five Romance languages (French, Spanish, Portuguese, Italian, Romanian). All the languages examined here share the main uses of articles: known referent, generic use, unique entities, abstract names, inalienable possession for the definite article, or introduction of a new element into the discourse and description for the indefinite article. However, we wanted to show some peculiarities. We used the same text in five languages, (La sombra del viento, Carlos Ruiz Zafón) which is part of the RomCro corpus, composed in the Chair of Romance Linguistics of the Department of Romance Studies, Faculty of Humanities, University of Zagreb, Croatia. The results of the analysis showed a clear difference between French and the other languages. As expected, French uses the indefinite article in plural much more often, as well as the partitive article, which does not exist in Spanish, Portuguese and Romanian. Likewise, the possessive adjective is more common in French than in other languages which use the definite article instead. But what is particularly interesting are the differences which indicate a ""change of perspective"", namely a different kind of article than in the original text. Our conclusion is that the noun can have several characteristics at the same time (description or determination by complement, generic use or absence of specific referent etc.) of which the author (or the translator) chooses the one to highlight. Likewise, we have underlined the role of article zero, which can carry different values (unspecified referent, but also unspecified quantity or even definite article value if the noun is introduced by a preposition), depending on its relationship to other articles in the language.

A systematic revision of the genus Neopterygosoma Fajfer, 2019 (Acariformes: Pterygosomatidae) with the description of a new species

A systematic revision of the scale mites of the genus Neopterygosoma Fajfer, 2019 (Acariformes: Pterygosomatidae) formerly placed in the genus Pterygosoma Peters, 1849, is presented. Two new natural species groups are established: the chilensis group for species found on Chilean liolaemid lizards (Sauria: Liolaemidae) and the patagonica group for N. patagonica (Dittmar de la Cruz, Morando & Avila, 2004) found on several Liolaemus spp. from Argentina. A neotype of N. patagonica is designated. A leg chaetotaxy model for tarsi-coxae I–IV is proposed for the genus. A key to all species of Neopterygosoma is provided and a full list of Neopterygosoma spp. with their updated host associations and distribution data is compiled. Additionally, a new species, N. schroederi n. sp. found on Liolaemus schroederi Müller & Hellmich, is described, including for the first time, description and illustrations of the immature stages of a species of Neopterygosoma.

Quantifying Inaccuracies in Modeling COVID-19 Pandemic within a Continuous Time Picture

Typically, mathematical simulation studies on COVID-19 pandemic forecasting are based on deterministic differential equations which assume that both the number (n) of individuals in various epidemiological classes and the time (t) on which they depend are quantities that vary continuous. This picture contrasts with the discrete representation of n and t underlying the real epidemiological data reported in terms daily numbers of infection cases, for which a description based on finite difference equations would be more adequate. Adopting a logistic growth framework, in this paper we present a quantitative analysis of the errors introduced by the continuous time description. This analysis reveals that, although the height of the epidemiological curve maximum is essentially unaffected, the position Tc1/2 obtained within the continuous time representation is systematically shifted backwards in time with respect to the position Td1/2 predicted within the discrete time representation. Rather counterintuitively, the magnitude of this temporal shift τ ≡ Tc1/2 − Td1/2 < 0 is basically insensitive to changes in infection rate κ. For a broad range of κ values deduced from COVID-19 data at extreme situations (exponential growth in time and complete lockdown), we found a rather robust estimate τ ≈ -2.65 day-1. Being obtained without any particular assumption, the present mathematical results apply to logistic growth in general without any limitation to a specific real system.

Small crowns of Russian empresses in the XVIII – early XIX centuries: creation, presence, artistic attributes

The object of this research is the small crowns of Russian empresses of the XVIII &ndash; early XIX century. The goal of this work consists in specification of circumstances of the creation and presence of small imperial crowns in Russia of that time, description of their artistic attributes, and analysis of these regalia as the works of jewelry art, considering stylistic evolution. For achieving the designated goal, the author applied comprehensive method of research based on the combination of art criticism and historical-cultural approach, referring to a range of sources: from unpublished archival documents and memoirs of contemporaries to visual material. The article clarifies the term &ldquo;small&rdquo; crown. Based on the archival documents, the author introduces into the scientific discourse the records on a number previously unknown small crowns, as well as specifies the circumstances of their creation along with names of the craftsmen. The artistic image of small Imperial crowns was analyzed for the first time. The conducted research demonstrates that in the XVIII century this image transformed under the influence of stylistic preferences in Russian artistic culture and due to the change of court jewelers who belonged to different schools of jewelry art. In the XIX century, influenced by the national ideas and according to the already established state ceremonial, which tends to traditionalism, the exterior of small crowns was fully oriented towards the small crown of 1797.

Analytical Model for Tsunami Propagation including Source Kinematics

&lt;p&gt;There are only a few analytical 2+1 D models for tsunami propagation, in which most of them treat the tsunami generation as an isolated part from a static deformation field, usually obtained from seismic models. This work examines the behavior of the tsunami propagation in a simple set-up including a time source function which accounts for a time description of the rupture process on the seismic source. An analytical solution is derived in the wavenumber domain, which is quickly inverted to space with the Fast Fourier Transform. The solution is obtained in closed form in the 1+1D case. The inclusion of temporal parameters of the source such as rise time and rupture velocity reveals a specific domain of slow earthquakes that enhance the tsunami amplitudes and produce non-negligible shifts on the arrival times. The obtained results confirm that amplification occurs when the rupture velocity matches the long-wave tsunami speed and the static approximation corresponds to a limit case for (relatively) fast ruptures.&amp;#160;&lt;/p&gt;