Hidden solitons in the Zabusky-Kruskal experiment: Analysis using the periodic, inverse scattering transform

Recent numerical work on the Zabusky--Kruskal experiment has revealed, amongst other things, the existence of hidden solitons in the wave profile. Here, using Osborne's nonlinear Fourier analysis, which is based on the periodic, inverse scattering transform, the hidden soliton hypothesis is corroborated, and the \emph{exact} number of solitons, their amplitudes and their reference level is computed. Other "less nonlinear" oscillation modes, which are not solitons, are also found to have nontrivial energy contributions over certain ranges of the dispersion parameter. In addition, the reference level is found to be a non-monotone function of the dispersion parameter. Finally, in the case of large dispersion, we show that the one-term nonlinear Fourier series yields a very accurate approximate solution in terms of Jacobian elliptic functions.Comment: 10 pages, 4 figures (9 images); v2: minor revision, version accepted for publication in Math. Comput. Simula

Krooniliste maksahaiguste ravi võimalikkusest

Kroonilised maksahaigused, hepatiit ja maksa- tsirroos, on sagedased ja olulised haigused. Kroonilisi maksahaigusi võib jaotada mitmeti, näiteks hinnates histoloogilisi muutusi maksakoes ehk põletikulist aktiivsust või fibroosi olemasolu (1). Olulisemaks on aga etioloogia ehk maksa- kahjustuse tekkepõhjus, sest sellest tulenevad ka ravisoovitused. Sagedasemad kroonilised maksahaigused on maksa alkoholtõbi ja krooniline viirushepatiit, mis moodustavad 70–80% kõigist kroonilistest maksahaigustest. Kuni 80% kroonilise viirushepatiidi juhtudest on põhjustanud C-hepatiidi viirus. Harvemad on primaarne biliaartsirroos (kuni 2% kõigist maksahaigustest), autoimmuunhepatiit (1–2%), primaarne skleroseeriv kolangiit ja ka maksa pärilikud ainevahetushaigused

Juri Lotman ja semiootika Tartu Ülikoolis

Juri Lotman and semioticsat the University of TartuOf all the researchers who have worked at the University of Tartu,Juri Lotman (1922–1993, in the University of Tartu 1954–93) is stillone of the most well-known in the field of the humanities. Duringhis lifetime he competed mainly with Paul Ariste (1905-1990, Estonianlinguist) and already then the two individuals were juxtaposedin terms of the “own and other” opposition. Even the semiotics thatLotman developed is still surrounded by a certain nimbus of estrangementand not only in the Estonian context. The article focuses, onthe one hand, on Lotman’s relations with Estonia as a person, hisplace and importance in the Estonian history of thought, on the otherhand, it observes the development of semiotics as a discipline in Estoniain the light of the reception of Lotman’s works

Tulevik ilma C-hepatiidita – tõusev täht on maksarasvtõbi

Maksarasvtõbi on sage haigus, mida arvatakse esinevat 20–40%-l Euroopa ja PõhjaAmeerika inimestest. Enamikul maksarasvtõve patsientidest on veel vähemalt üks metaboolse sündroomi tunnus ja seega võib maksarasvtõbi olla metaboolse sündroomi (abdominaalne rasvumine, arteriaalne hüpertensioon, düslipideemia, 2. tüüpi diabeet, insuliiniresistentsus) maksaväljendus. Maksarasvtõve avaldusvormid on rasvmaks (ingl nonalcoholic fatty liver), steatohepatiit ehk rasvhepatiit (ingl nonalcoholic steatohepatitis) ja steatohepatiidist kujunenud maksatsirroos. Maksarasvtõve diagnoosimiseks peab olema tõestatud rasvmaksa ja/või steatohepatiidi olemasolu kas ultraheliuuringul või maksabiopsial, patsiendil peaks puuduma alkoholiriskikasutus ja olema välistatud ka teised võimalikud kroonilise maksahaiguse põhjused. Steatohepatiidi diagnoosimisstandardiks on maksabiopsia, mis võimaldab välistada kroonilise maksahaiguse teised põhjused, hinnata steatohepatiidi ning maksafibroosi raskusastet ja seega maksarasvtõve prognoosi. Tsirroosistaadiumis maksarasvtõve patsiendil soovitatakse maksaanalüüse ning kõhuõõne ultraheliuuringut korrata iga kuue kuu järel. Patsiendi jälgimine söögitoru veenikomude ning maksarakkvähi tekke suhtes ja nii veenikomude kui ka maksarakkvähi edasine käsitlus ei erine teistel põhjustel tekkinud maksatsirroosiga patsientide käsitlemisest

Juri Lotman’s Typologies of Culture

One central concept in Juri Lotman’s semiotics of culture are cultural typologies, the objective of which is to describe the basic types of cultural codes, define the universals of human culture, and to create “a grammar of culture”, i. e. a unified system of the general structure of the universal characteristics of the “culture of humankind”. Lotman compares culture with a living organism as well as with a work of art, above all emphasizing the dynamicity of culture that is effected by two poles (i. e. consciousnesses) throughout the whole of cultural history: cyclical-continual (mythological) and linear-discrete (historical). The article views Lotman’s different conceptions of cultural typologies as a whole, where one and the same binary opposition is described in different ways and with different emphases, conclusively from which two universal types of culture are drawn out

C-hepatiidi viirusega seotud ekstrahepaatilised

C-hepatiidi viirus, põhjustades ägedat või kroonilist hepatiiti ning maksatsirroosi, võib olla patogeneetiline tegur ka mitmete teiste kliiniliste ilmingute kujunemisel. Tuntumad neist on segatüüpi krüoglobulineemia, mis manifesteerub hemorraagilise vaskuliidi ja artralgiaga (Meltzeri sündroom); naha hilisporfüüria; sekundaarne raualadestus ning lame lihhen. C-hepatiidi viirus võib osaleda ka mitmete lümfoproliferatiivsete haiguste patogeneesis. Eesti Arst 2007; 86 (5): 335–33

Gastroenteroloogia

Eesti Arst 2012; 91(4):21

Jannseni Eesti Põllumees (1868-1880)

Jannsen’s “Eesti Põllumees” (1868-1880)Johan Voldemar Jannsen holds a special role in the cultural history of Estonia — until 1875 the vast majority of Estonian periodicals were founded by Jannsen. Perno Postimees (1857–1863) and Eesti Postimees (1864–1880) that he edited were responsible for all the explanationand organisation work during the national awakening. Jakobson’s newspaper “Sakala” did not come into circulation until only 1878, while it took over all Jannsen’s subjects but wrote of them in a sharper manner. Greatly to him do we owe the myth of his competitor Jannsen’s turncoat nature. Jannsen did receive support from the Estonian and Livonian knightage and Society in 1870–1879 but this was first and foremost connected to the gentry’s attempts to presentthemselves as a supporter of the native’s cultural endeavours in the eyes of the locals and administration.In addition to the song festival and the organisation of song and music societies Jannsen attempted to found agricultural societies for the development of farmers’ skills and knowledge, while he also established a respective journal—Eesti Põllomees—that was published as a monthly supplement to the Baltische Wochenschrift, a journalissued by the Society.Hermann v. Samson, a versatile and difficult man, who organised support for Jannsen’s publications in Livonia and Estonia, was the official editor and most likely also the censor of the journal for the first half-year (1869). The newspaper was published on the first day of every month, the content was quite versatile and the illustrations in the style of wood engraving (author: Eduard Magnus Jakobson).The Society supported the publication with both subscriptions and financial contributions. The newspaper introduced practical methods of agriculture and animal husbandry, using manure and artificial manure, tending pastures, construction of farmhouses, nature protection issues, often in the form of a dialogue with the exemplary farmer Tiit from the farm of Niidu. After some time the content and regularity of publication of the newspaper began to decline. Jannsenbowed out from editing the paper in 1877, Põllumees transferred to the ownership of agricultural societies and was published regularly at first, providing accounts of the activities of the societies. However, already the next year ended with only a double issue (5/6) having been published and in 1879, no new issues came. In 1880 Jannsen commented that Põllumees had so to say returned to its father and the journal was published twice a month as a supplement of the EestiPostimees. At the end of the year Jannsen had a stroke and both Eesti Postimees as well as Põllumees went into decline. The last issue of the Põllumees was published in early 1889

Rektoraadis sula- ja stagnaajal

Malle SalupereMemoirs about working in rectorat of the University of Tartu in 1960ies and 1970ies

KROONILISE C-HEPATIIDI RAVIJUHEND

Krooniline C-hepatiit on oluline tervishoiuprobleem. C-hepatiidi (HCV) levimus maailma erinevates piirkondades on erinev, haigestunuid on mõnes piirkonnas isegi üle 10% rahvastikust; Eestis hinnanguliselt umbes 1%. Kuni 70% kroonilise viirushepatiidi juhtudest on põhjustanud C-hepatiidi viirus. C-hepatiidi viiruse ülekanne toimub põhiliselt nakatatud vere ja kehavedelike kaudu. Kuigi verekomponentide ülekande ja teiste meditsiiniliste protseduuride puhul järgitakse tänapäeval ohutusnõudeid, on siiski võimalik nakatuda C-hepatiidi viirusega. Eesti Arst 2006; 85 (9): 610–61