498 research outputs found
In memory of Professor Lech Wojtczak, researcher and person
No full textProfessor Lech Wojtczak spent his entire scientific life at the Nencki Institute of Experimental Biology PAS, where he worked since 1947. He is the author or co-author of two hundred scientific papers, promoted 15 doctors of science, was the Full Member of PAS and has been awarded with several prizes and honors. Among his students are three successive directors of the Nencki Institute, the authors of the present article. Scientific interests of Professor Lech Wojtczak were always dealing with bioenergectics, a discipline that he led in Poland and Eastern-Central Europe. In particular, his studies focused on the role of fatty acids and their derivatives on bioenergetics, on the regulatory role of surface potential of biomembranes on enzymatic and transport activities, on the regulatory role of calcium and magnesium in mitochondria, on the role of free oxigen radicals in bioenergetics, etc. Apart from being a great scientist, Lech Wojtczak was also a fantastic teacher, and an excellent scientific supervisor. Being well recognized in the world, he was placing members of his research group in foreign laboratories, as well as was sending tchem to courses and conferences. This was opening their minds to the world, and to other cultures, and allowed Lech Wojtczak to form from his collaborators the next generation of good scientists and future leaders. The list of the most important pupils of Professor Wojtczak is given in the article. Lech was also excellent in social contacts, and in creating a friendly atmosphere. Together with his wife Anna, they kept an open home, often inviting collaborators to parties that usually led to long scientific discussions. With the sudden death of Pofessor Lech Wojtczak Polish science suffered a great loss. This eminent researcher, the father of Polish bioenergetics, but also a warm and modest person, will be dearly missed
A REVIEW OF THE BOOK: PATRYK WAWRZYŃSKI, PREZYDENT LECH KACZYŃSKI. NARRACJE NIEDOKOŃCZONE [PRESIDENT LECH KACZYNSKI. THE UNFINISHED NARRATIVES], WYDAWNICTWO ADAM MARSZAŁEK, TORUŃ 2012
No full textWith these words of Mark Antony – as a motto – Patrick Wawrzyński could start his book. Published in 2012, the work is titled "President Lech Kaczynski. The unfinished narratives" (Prezydent Lech Kaczyński. Narracje niedokończone), and it is just such an attempt of doing justice to the tragically deceased president of the Republic of Poland. The author has undertaken the task of presenting the views of Lech Kaczynski as they actually were – separating them from incorrect interpretations and opinions attributed by other actors of the Polish political scene: his opponents as well as allies
In one breath (Jednym tchem) performed at the Theatre of the Eighth Day
No full textThis text deals with the 1971 play Jednym tchem (In one breath), performed at the Theatre of the Eighth Day (Teatr Ósmego Dnia) and based on Stanisław Barańczak’s poem. Lech Raczak outlines the methods used in the play, the characters, way of presenting a poetic text and the music in the performance. The author uses fragments of performance records published in his previous book Szaleństwo i metoda. 48 tekstów o teatrze (Madness and method. 48 texts about theatre) (Wydawnictwo Miejskie Posnania, Poznań 2012).<br /
Lech Ratajski
No full textLech Ratajski was born on 26 April 1921, in Rawa Mazowiecka, in a teachers' family. In 1939 he obtained the school-leaving certificate in Łomża. During the II World War he worked as a teacher and a clerk. He was also a member of the Home Army (AK) and he took part in the sabotage actions for which in 1949 he was honoured with the Cross of Valour. After the war he studied at the Academy of Fine Arts in Cracow for two years. In 1950 he graduated of the Jagiellonian University in Cracow with a degree in geography. As a student he collaborated with the popular monthly magazine „Poznaj Świat” (Know the World) for which he elaborated maps, designed covers, and wrote short notes. In 1950, accordingly to his interests, he took a post at the Department of Regional Geography within the Geographical Institute of the University of Warsaw. He wrote on the subject of the geographic names and in 1959 he was a co-author of the extensive specification comprising 20,000 geographical names. He was also the co-author of the wall economic charts of Poland and of the world, that were innovative in the Polish cartography of those days. He continuously collaborated with the magazine „Poznaj Świat” that was being published in Warsaw since the end of 1955 and he was its Editor-in-chief since 1968. He was the author of many articles and notes on the regional geography and of a book - a compendium of knowledge on Africa. The main field of his scientific interest was the thematic cartography, especially the economic maps and to this issue both his dissertations were related: the doctor's dissertation (1962) on the achievements of the Polish economic cartography in 20th century and the habilitation dissertation ( 1966) on industrial maps and their cartometric value. He devised the model of the cartographic methods of presentation, the model of cartographic generalisation, and the proposition of economic maps signs standardisation. Since 1968 he was the chairman of the Working Group and later of the Commission on Communication in Cartography at the International Cartographical Association (ICA). In the academic year 1971/1972 he lectured at the University of Edmonton and participated in the International Cartographical Association conference in Ottawa, at which he was elected the Vice-president of the Association. During his stay in Canada he prepared the textbook Methodology of the socioeconomic cartography that was published in 1973, and its second, updated edition was published in 1989. At the end of 1967 he was appointed the professorship at the Chair of Cartography where he introduced many didactic innovations - among others the free-hand drawing. In 1973 he employed dr W. Grygorenko (the future Chairman of the Chair) to teach computer cartography to the students. He tutored approximately 90 master's thesis, including 17 on the economic charts of the Polish voivodeships. In 1973- 1977 four employees of his Chair were promoted doctors. In 1973 Lech Ratajski obtained the title of a professor. He served several functions at the Polish Geographic Society, among others he was the President of the Commission of Cartography. In 1976 he was honoured with the medal of the Society. His bibliography comprises over 400 items including over 150 on cartography. He was the author of 30 portable and wall maps and approx. 600 annex maps to articles, books, and encyclopedias. Lech Ratajski died on 22 November 1977, in Warsaw
The spin dependent odderon in the diquark model
No full textAbstractIn this short note, we report a di-quark model calculation for the spin dependent odderon and demonstrate that the asymmetrical color source distribution in the transverse plane of a transversely polarized hadron plays an essential role in yielding the spin dependent odderon. This calculation confirms the earlier finding that the spin dependent odderon is closely related to the parton orbital angular momentum
Phenomenological tests of perturbative quantum chromodynamics at high energy at the LHC
No full textDans la limite des hautes énergies, la petite valeur de la constante de couplage de l'interaction forte peut être compensée par l'apparition de grands logarithmes de l'énergie dans le centre de masse. Toutes ces contributions peuvent être du même ordre de grandeur et sont resommées par l'équation de Balitsky-Fadin-Kuraev-Lipatov (BFKL). De nombreux processus ont été proposés pour étudier cette dynamique. L'un des plus prometteurs, proposé par Mueller et Navelet, est l'étude de la production de deux jets vers l'avant séparés par un grand intervalle en rapidité dans les collisions de hadrons. Un calcul BFKL ne prenant en compte que les termes dominants (approximation des logarithmes dominants ou LL) prédit une augmentation rapide de la section efficace avec l'augmentation de l'intervalle en rapidité entre les jets ainsi qu'une faible corrélation angulaire. Cependant, des calculs basés sur cette approximation ne purent pas décrire correctement les mesures expérimentales de ces observables au Tevatron. Dans cette thèse, nous étudions ce processus à l'ordre des logarithmes sous-dominants, ou NLL, en prenant en compte les corrections NLL aux facteurs d'impact, qui décrivent la transition d'un hadron initial vers un jet, et à la fonction de Green, qui décrit le couplage entre les facteurs d'impact. Nous étudions l'importance de ces corrections NLL et trouvons qu'elles sont très importantes, ce qui conduit à des résultats très différents de ceux obtenus à l'ordre des logarithmes dominants. De plus, ces résultats dépendent fortement du choix des échelles présentes dans ce processus. Nous comparons nos résultats avec des données récentes de la collaboration CMS sur les corrélations angulaires des jets Mueller-Navelet au LHC et ne trouvons pas un bon accord. Nous montrons que cela peut être corrigé en utilisant la procédure de Brodsky-Lepage-Mackenzie pour fixer le choix de l'échelle de renormalisation. Cela conduit à des résultats plus stables et une très bonne description des données de CMS. Finalement, nous montrons que, à l'ordre des logarithmes sous-dominants, l'absence de conservation stricte de l'énergie-impulsion (qui est un effet négligé dans un calcul BFKL) devrait être un problème beaucoup moins important qu'à l'ordre des logarithmes dominants.In the high energy limit of QCD, the smallness of the strong coupling due to the presence of a hard scale can be compensated by large logarithms of the center of mass energy. All these logarithmically-enhanced contributions can be resummed by the Balitsky-Fadin-Kuraev-Lipatov (BFKL) equation. Many processes have been proposed to study these dynamics. Among the most promising ones is the production of two forward jets separated by a large interval of rapidity at hadron colliders, proposed by Mueller and Navelet. A BFKL calculation taking into account only dominant contributions (leading logarithmic, or LL, accuracy) predicts a strong rise of the cross section with increasing rapidity separation between the jets and a large decorrelation of their azimuthal angles. However, such LL calculations could not successfully describe measurements of these observables performed at the Tevatron. In this thesis, we study this process at next-to-leading logarithmic (NLL) accuracy, taking into account NLL corrections both to the impact factors, which describe the transition from an incoming hadron to a jet, and to the Green's function, which describes the coupling between the impact factors. We investigate the magnitude of these NLL corrections and find that they are very large, leading to very different results compared with a LL calculation. In addition, we find that these results are very dependent on the choice of the scales involved in the process. We compare our results with recent data from the CMS collaboration on the azimuthal correlations of Mueller-Navelet jets at the LHC and find a rather poor agreement. We show that this can be cured by using the Brodsky-Lepage-Mackenzie procedure to fix the renormalization scale. This leads to more stable results and a very good description of CMS data. Finally, we show that at NLL accuracy the absence of strict energy-momentum conservation (which is a subleading effect in a BFKL calculation) should be a much less severe issue than at LL accuracy
Sonder la saturation des gluons dans les processus semi-durs γ(*)+p/A
No full textDans les collisionneurs à haute énergie, les processus QCD impliquent au moins deux échelles: l’énergie dans le centre de masse s et une échelle dure Q^2 qui permet la factorisation des processsus en une partie dure calculable via les méthodes perturbatives des diagrammes de Feynman et une partie non-perturbative comme par exemple les fonctions de distribution de partons (PDFs). Cependant, des grands logarithmes peuvent apparaître compensant la petitesse de la constante de couplage. Ces corrections doivent être resommées et cela mène aux équations d’évolution Dokshitzer-Gribov-Lipatov-Altarelli-Parisi (DGLAP) aux énergies modérées. Dans la limite semi-dure, appelée aussi limite de Regge-Gribov, characterisée par s >> Q^2 >> Λ^2_QCD, des grands logarithmes de l’énergie doivent être resommés via l’approche Balitsky-Fadin-Kuraev-Lipatov (BFKL). Dans cette limite des hautes énergies, les gluons dominent la structure interne des nucléons et que ce soit dans le formalisme de BFKL ou de DGLAP, la distribution de gluon augmente avec l’énergie du centre de masse, ce qui ne peut pas continuer indéfiniment car cela mène à une augmentation des sections efficaces avec l’énergie qui éventuellement viole l’unitarité. Aux très hautes énergies, des effets non-linéaires comme la recombinaison de gluons ont été prédits, menant à la saturation gluonique. Des signes de cette saturation ont été trouvés dans les données expérimentales actuelles, mais aucune n’est concluante. Il est clair qu’une découverte sans ambiguïté de cette saturation gluonique nécessite l’identification et le calcul précis au-delà de l’ordre dominant d’observables sensible à la physique de la saturation. Cette thèse participe aux récents efforts menés par la communauté des hautes énergies afin d’atteindre ce but. Deux théories effectives équivalentes, qui sont toutes deux introduites dans le manuscrit, sont utilisées dans les calculs analytiques d’observables variées pouvant être étudiées expérimentalement au Grand collisionneur de hadrons (LHC) via des collisions ultra-périphériques ou dans des collisionneurs futurs, principalement le collisionneur électron-ion (EIC) et le Grand collisionneur électron-hadron (LHeC) via des diffusions profondément inélastiques inclusives ou diffractives. Nous proposons et étudions tout particulièrement deux nouvelles classes de processus dans le but de mettre en évidence la saturation gluonique. Tout d’abord, l’approche des ondes de choc est utilisée dans le calcul à l’ordre sous-dominant en perturbation des sections efficaces de production diffractive d’une paire de hadrons et de production diffractive d’un seul hadron dans une collision γ(*) + p/A, le photon pouvant être réel ou virtuel. Nous démontrons d’abord que les différentes divergences (molles, colinéaires, en rapidité et ultra-violettes) s’éliminent entre elles puis nous extrayons analytiquement le terme fini. Par ailleurs, nous calculons à l’ordre dominant, à l’aide du formalisme du condensat de verre de couleur, la section efficace de production inclusive de quarkonium + gluon dans une collision profondément inélastique.At high-energy colliders, QCD processes involve at least two scales: the centre-of-mass energy s and a hard scale Q^2 that allows the factorization of processes into a hard part computable using the perturbative methods of Feynman diagrams and a non-perturbative part such as parton distribution functions (PDFs). However, large logarithmic corrections can arise, compensating the smallness of the coupling constant. They have to be resummed, leading to the Dokshitzer-Gribov-Lipatov-Altarelli-Parisi (DGLAP) evolution equations at moderate energies. In the semi-hard limit or Regge-Gribov limit characterized by s >> Q^2 >> Λ^2_QCD, the large energy logarithms are resummed using the Balitsky-Fadin-Kuraev-Lipatov (BFKL) approach. In this high-energy domain, gluons dominate the inner structure of nucleons. In both BFKL and DGLAP formalisms, a rise of the gluon distribution is predicted. This rise cannot indefinitely continue as it leads to a growth of cross-sections with energy that eventually violate unitarity. At very high energy, non-linear effects such as gluon recombination have been theoretically predicted, leading to gluon saturation. Strong hints of gluon saturation have been found in the currently available experimental data but they have not been conclusive. It has been clear that its unambiguous discovery requires the identification and precise beyond leading order computations of observables that are sensitive to saturation physics. This thesis contributes to the efforts, in recent years, of the high-energy physics community towards such a goal. Two equivalent effective field theories -that will be both introduced in the thesis- have been employed to analytically compute various observables that can be studied experimentally at the Large Hadron Collider (LHC) with ultra-peripheral collisions or at future colliders, mainly the Electron-Ion Collider (EIC) and the Large Hadron electron Collider (LHeC) in diffractive or inclusive Deep Inelastic Scattering (DIS). We propose and study two novel types of processes to investigate saturation physics. First, we use the shockwave approach to calculate at the next-to-leading order the cross-section for di-hadron and single-hadron diffractive production in γ(*) + p/A collision, i.e. in electro- or photoproduction. We show the explicit cancellation of the different divergences (soft, collinear, in rapidity and ultraviolet) and extract the finite term. Second, we compute the cross-section for the inclusive quarkonium + gluon production in DIS at leading order using the Colour Glass Condensate (CGC) formalism
Jak uprawiać humanistykę? W stronę polityki wrażliwości
No full textThe paper reports from the author’s perspective the debate on the book by M.P. Markowski Polityka wrażliwości. Wprowadzenie do humanistyki (Kraków: Universitas, 2013). This debate was organized within the Framework of the Conrad Festival in Cracow in 2013, and the participants were the following professors: Michał Paweł Markowski as the author of the book himself, Ryszard Nycz as the moderator of discussion, Agata Bielik-Robson, Krzysztof Kłosiński and Lech Witkowski, together with Grzegorz Jankowicz represen ing the journal „Tygodnik Powszechny”. The key question for the debate was linked with the issue whether and in what a way one can defend the value of humanities in their contrast with the scientific rigour on one side, and the neoliberal afirmation of equivalence of banality on the other.
Artykuł przedstawia z perspektywy autora debatę poświęconą książce M.P. Markowskiego Polityka wrażliwości. Wprowadzenie do humanistyki (Kraków: Universitas, 2013). Debata została zorganizowana w ramach Festiwalu Conrada w Krakowie w 2013 roku, a jej uczestnikami byli następujący profesorowie: Michał Paweł Markowski jako autor książki, Ryszard Nycz jako moderator dyskusji, Agata Bielik-Robson, Krzysztof Kłosiński i Lech Witkowski, a także Grzegorz Jankowicz reprezentujący tygodnik „Tygodnik Powszechny”. Kluczowe pytanie debaty dotyczyło tego, czy i w jaki sposób można bronić wartości nauk humanistycznych w konfrontacji z rygorem naukowym z jednej strony i neoliberalnym afirmowaniem równoważności banalności z drugiej
Election posters of “Citizens’ Committee with Lech Wałęsa” candidates
No full textThe article solves the mystery of the “Citizens’ Committee with Lech Wałęsa” election posters that paved the way to the victory of Solidarity in June 1989. For 25 years the issue of posters has not raised any controversy. The historians presupposed that each member of the Committee had had an election poster with the leader of Solidarity movement on it. The article refutes that myth. Having analyzed historical documents and eyewitness memories, the author uncovers which candidates did not have this kind of poster
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