219 research outputs found
Anti-solar differential rotation and surface flow pattern on UZ Librae
We re-investigate UZ Librae spectra obtained at KPNO in 1998 and 2000. From
the 1998 data we compose 11 consecutive Doppler images using the Ca I-6439, Fe
I-6393 and Fe I-6411 lines. Applying the method of average cross-correlation of
contiguous Doppler images we find anti-solar differential rotation with a
surface shear of alpha ~ -0.03. The pilot application of the local correlation
tracking technique for the same data qualitatively confirms this result and
indicates complex flow pattern on the stellar surface. From the
cross-correlation of the two available Doppler images in 2000 we also get
anti-solar differential rotation but with a much weaker shear of alpha ~
-0.004.Comment: 3 pages, 3 figures, submitted to A
Effects of Solar Active Regions on Meridional Flows
The aim of this paper is to extend our previous study of the solar-cycle
variations of the meridional flows and to investigate their latitudinal and
longitudinal structure in the subphotospheric layer, especially their
variations in magnetic regions. Helioseismology observations indicate that mass
flows around active regions are dominated by inflows into those regions. On
average, those local flows are more important around leading magnetic
polarities of active regions than around the following polarities, and depend
on the evolutionary stage of particular active regions. We present a
statistical study based on MDI/SOHO observations of 1996-2002 and show that
this effect explains a significant part of the cyclic change of meridional
flows in near-equatorial regions, but not at higher latitudes. A different
mechanism driving solar-cycle variations of the meridional flow probably
operates.Comment: 4 pages, 5 figures, accepted for publication in ApJ
Ke Klaretovu spisu Complexionarius
Příspěvek je věnován Klaretově didaktické básni Complexionarius, jejímu popisu a obsahovému rozboru. V kontextu dalších Klaretových děl má spis svým tématem i dobou svého vzniku (pravděpodobně 40. léta 14. století) blízko k regiminu Medicaminarius, zaměřen je ovšem úžeji na výklad o lidských complexiones (povahách) a o jejich proměnách. Pozornost je věnována struktuře textu a tomu, jakým způsobem se v něm odráží nauka o septem res naturales. Autor třídí Klaretovy poznatky k jednotlivým complexiones a nově identifikuje některé textové shody s obdobným výkladem v díle Flos medicinae Scholae Salerni. Jako učební text Complexionarius poskytuje vhled do jedné z oblastí teorie medicíny, jak byla v českém prostředí pěstována v polovině 14. století.The article deals with Claretus’ didactic poem Complexionarius (written before 1348) and provides its description and content analysis. Among other Claretus’ writings it is related to Medicaminarius, a regimen sanitatis written in the same decade. The poem of 944 leonine verses describes the four human complexiones (temperaments) and puts them into context of so called septem res naturales. Structure of the poem and content of each chapter is outlined, Claretus’ method for characterization of each complexio is introduced, and Salernitan Rule of Health is identified as one of author’s sources. As a schooltext, Complexionarius allows us to take a look inside the medical theory as it was taught in the middle of 14th century in Bohemia
Husova Enarratio Psalmorum: K Husově metodě výkladu žalmů
Příspěvek si klade za cíl seznámit čtenáře s Husovým spisem Enarratio Psalmorum, v němž je podán výklad žalmů 109-118. Úvodem stručně shrnuje okolnosti vzniku díla a jeho dochování, následně představuje autorovy prameny a poukazuje na způsob, jakým s nimi nakládá. Největší část příspěvku je věnována vnitřní struktuře výkladů žalmů a zejména jednotlivých veršů. V malých obměnách se ve výkladech pravidelně opakuje trojčlenné schéma: tematizace verše, jeho parafráze a detailní rozbor vybraných výrazů vykládaného verše. Závěrem je poukázáno na některé problémy spojené s přípravou edice textu v rámci 17. svazku Husových Opera omnia.The article aims at introducing the reader to Hus' treatise Enarratio Psalmorum, which offers interpretation of Psalms 109-118. It shortly summarizes the circumstances of the origin and preservation of the treatise, presents the author's sources and shows how he worked with them. The central part of the study focuses on the internal organization of psalm explanation especially on the structure of the commentaries to individual verses. A tripartite scheme (with minor alterations) is typical of Hus' interpretation: thematization of the verse, its elaborate paraphrase and a detailed analysis of expressions that appear in the verse. In conclusion, the paper points out some difficulties connected with the preparation of a critical edition of this text, which will appear as the 17th volume of Hus' Opera omnia series
Klaretův Medicaminarius: jeho obsah a základní pramen
Příspěvek je věnován Klaretově didaktické básni Medicaminarius, který se žánrově řadí mezi tzv. regimina sanitatis. Je nastíněn obsah jednotlivých kapitol a u každé z nich je uveden počet veršů převzatých nebo alespoň inspirovaných Klaretovým hlavním pramenem, totiž souborem Regimen sanitatis Salernitanum. Protože v edici textu (Klaret a jeho družina I, ed. V. Flajšhans, 1926) nejsou přejaté verše vyznačeny, druhou část příspěvku tvoří kompletní přehled textových shod obou básní, z něhož mimo jiné vyplývá, že z uvedeného pramene pochází cca 51 % veršů Klaretova spisu.The article deals with Claretus’ didactic poem Medicaminarius (written before 1348), which is one of the many so called regimina sanitatis of the Middle Ages. The content of each chapter is outlined and the number of verses borrowed from its primary source (Regimen sanitatis Salernitanum) is given. As in the edition of the poem (Klaret a jeho družina I, ed. V. Flajšhans, 1926) the exact extent of such borrowings is not indicated, the second part of the paper provides a complete list of verses borrowed from or inspired by the Salernitan Rule of Health. It comes out that about 51 % of the verses come from this very source
K recepci antiky v Kosmově kronice
Příspěvek přináší několik postřehů k vnímání antiky u autora Kosmovy kroniky (1119-1125). Jak už počátkem minulého století ukázal A. Kolář, děkan svatovítské kapituly Kosmas ve větší míře než ostatní soudobí kronikáři ve středoevropském prostoru používá nejenom citáty a parafráze z římských klasiků, ale v rámci historického vyprávění hojně zapojuje i motivy převzaté z řeckořímské mytologie a historie. Autor příspěvku poukazuje na skutečnost, že při charakteristice některých postav stojí v těsné blízkosti křesťanské a pohanské atributy a motivy, aniž by si vzájemně konkurovaly. Může to být dokladem dokončené christianizace českých zemí. V závěru je na vybraném příkladě ilustrována možná mnohovrstevnost některých narážek a odkazů, jež mohly být srozumitelné vzdělaným adresátům díla v Kosmově současnosti, dnešnímu čtenáři však zůstávají zpravidla skryté.The article brings some observations to the reception of antiquity in Cosmas' Chronica Boemorum (1119-1125). It refers to the influential study Kosmovy vztahy k antice (1925) written by A. Kolář, which demonstrated that in his work Cosmas, dean of the church of Prague, quoted the Roman classics and used the motifs from Greek and Roman mythology and history significantly more than other historiographers of the time in the central European region. The article points out that Cosmas puts together Christian and pagan attributes while describing some of his characters without feeling it as discrepancy, which could be a sign of completed Christianization of the Czech territory. At the end there is an example given which illustrates possible "multilayerness" of meaning in some references that could be comprehensible to the educated audience in Cosmas' present, but they are not quite clear to us nowadays
Łacińska terminologia medyczna w praktyce
The article aims to discuss the use of authentic medical documentation in Latin medical terminology classes for students of medicine during their year at Masaryk University in
Brno. Despite the limited access to medical records, for students still lacking experience in clinical medicine, as well as for terminology teachers not educated in medicine itself, but in philology, the use of medical documentation proves to be a highly motivating component of training,
allowing students to observe how technical medical Latin is used in real life situations as well
as making classes more practica
Master Claretus’ Early Didactic Writings on Medicine
Claretus (Bartholomaeus de Solentia) is known as the author of the oldest Latin-Czech dictionaries, but the aim of the article is to introduce his didactic poems Medicaminarius and Complexionarius. Although quite a number of similar school texts were created during the Middle Ages, not many of them originated in the Czech lands. They provide an insight into medical theory as it was taught in Bohemia in the mid 14th century
Combined helioseismic inversions for 3D vector flows and sound-speed perturbations
Time-distance helioseismology is the method of the study of the propagation
of waves through the solar interior via the travel times of those waves. The
travel times of wave packets contain information about the conditions in the
interior integrated along the propagation path of the wave. We introduce an
improved methodology of the time-distance helioseismology which allows us to
invert for a full 3D vector of flows and the sound-speed perturbations at once.
Using this methodology one can also derive the mean value of the vertical
component of flows and the cross-talk between the flows and the sound-speed
perturbations. We used the SOLA method with a minimisation of the cross-talk as
a tool for inverse modelling. In the forward model, we use Born approximation
travel-time sensitivity kernels with the Model S as a background. The
methodology was validated using forward-modelled travel times with both mean
and difference point-to-annulus averaging geometries applied to a snapshot of
fully self-consistent simulation of the convection. We tested the methodology
on synthetic data. We demonstrate that we are able to recover flows and
sound-speed perturbations in the near-surface layers. We have taken the
advantage of the sensitivity of our methodology to entire vertical velocity,
and not only to its variations as in other available methodologies. The
cross-talk from both the vertical flow component and the sound-speed
perturbation has only a negligible effect for inversions for the horizontal
flow components. The inversions for the vertical component of the vector flows
or for the sound-speed perturbations are affected by the cross-talk from the
horizontal components, which needs to be minimised in order to provide valid
results. It seems that there is a nearly constant cross-talk between the
vertical component of the vector flows and the sound-speed perturbations.Comment: 13 pages, 18 figure
Space-time segmentation method for study of the vertical structure and evolution of solar supergranulation from data provided by local helioseismology
Solar supergranulation remains a mystery in spite of decades of intensive
studies. Most of the papers about supergranulation deal with its surface
properties. Local helioseismology provides an opportunity to look below the
surface and see the vertical structure of this convective structure. We present
a concept of a (3+1)-D segmentation algorithm capable of recognising individual
supergranules in a sequence of helioseismic 3-D flow maps. As an example, we
applied this method to the state-of-the-art data and derived descriptive
statistical properties of segmented supergranules -- typical size of 20--30 Mm,
characteristic lifetime of 18.7 hours, and estimated depth of 15--20 Mm. We
present preliminary results obtained on the topic of the three-dimensional
structure and evolution of supergranulation. The method has a great potential
in analysing the better data expected from the helioseismic inversions, which
are being developed.Comment: 6 pages, 4 figures, accepted in New Astronom
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