162,625 research outputs found

    Rethinking Leucine Zipper : ribonuclease activity and structural dynamics of a ubiquitous oligomerization motif

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    This dissertation focuses on structural, dynamic and catalytic properties of a Leucine Zipper (LZ) motif – a family of protein oligomerization domains which belong to the structural class of coiled coil proteins. LZ possess unique stability owing to high abundance of leucine residues in the key positions of the oligomerization interface. This allows increased combinatorial flexibility for the sidechains in coiled coil positions defining oligomerization specificity, thus making LZ an ideal protein-protein interaction determinant. This potential is reflected in the omnipresence of LZ within protein signalling pathways. Summarized in the Chapter I, we review the structure, interaction specificity, folding characteristics and functional diversity of LZ motifs, revealing the molecular mechanisms underlying LZ-enabled protein signaling. Beyond the widely acknowledged role of a protein oligomerization motif, recently it was shown that LZ motifs from bZIP factors GCN4 and cJun are capable of catalyzing degradation of RNA. Moreover catalytic RNase activity is conserved within full-length bZIP factors. This discovery was made in the laboratory of Prof. Bernd Gutte (University of Zurich) and served as a basis for the structural studies of LZ presented in this thesis. The manuscript presented as the Chapter II summarizes the results of the initial LZ RNase studies, performed in collaboration with Christine Deillon and Stefan Hoffman. Our first structural trials on LZ-GCN4 employing solution NMR led to the discovery of the x-form – a novel monomeric folding intermediate of LZ that exists in equilibrium with the classical coiled coil state. Although marginally populated at experimental in vitro conditions, x-form might represent a considerable fraction of the LZ structural ensemble in vivo, providing a transient interface for specific recombination of interaction partners within bZIP networks. Results of these studies are presented as Chapter III of this thesis. Finally, our structural NMR studies of LZ–RNA interactions have shown that the substrate interacts with the coiled coil (dimeric) conformation, while the x-form is incapable of binding RNA molecules. This is supported by the fact that the catalytic site is formed at the interface of two LZ chains, and therefore is only available upon assembly of the coiled coil dimer. Experimental data show that LZ from GCN4 and cJun differ in the topology and catalytic properties of the active site, which points to the ability of LZ to provide a general scaffold for assembly of catalytic sites with different properties. These results are presented in the Chapter IV of this thesis

    Prof. Th. W. Adorno and the author Hans Erich Nossack.

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    Prof. Th. W. Adorno and the author Hans Erich Nossack at a reception of Insel Verlag, Buchmesse Frankfurt 1966LB

    DNA Zipper-Based Tweezers

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    Here we report the design and development of DNA zippers and tweezers. Essentially a zipper system consists of a normal strand (N), a weak strand (W), and an opening strand (O). N strand is made up of normal DNA bases, while W is engineered to have inosine substituting for guanine. By altering the number and order of inosine, W is engineered to provide less than natural bonding affinities to N in forming the [N:W] helix. When O is introduced (a natural complement of N), it competitively displaces W from [N:W] and forms [N:O]. This principle is incorporated in the development of a molecular device that can perform the functions of tweezers (sense, hold, and release). Tweezers were constructed by holding N and W together using a hinge at one end. Thus, when the tweezers open, N and W remain in the same vicinity. This allows the tweezers to cycle among open and close positions by their opening and closing strands. Control over their opening and closing kinetics is demonstrated. In contrast to the previously reported DNA tweezers, the zipper mechanism makes it possible to operate them with opening strands that do not contain single-stranded DNA overhangs. Our approach yields a robust, compact, and regenerative tweezer system that could potentially be integrated into complex nanomachines

    Nowe spojrzenie na planowanie architektury mieszkaniowej w afryce subsaharyjskiej

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    The author shares his reflections on state of art in housing and urban planning, deficiencies, expectations and possibilities in the Sahel region of Africa. He notices, that the housing problem in Africa is one of the challenges, which should be solved in order to recover life dignity of African people and secure their rights to traditional family life in acceptable conditions. The paper describes the studies on the typical dispersed urban structures and the need to foster this type of settlement structure and proposals of introduction of new on light steel frame housing system in the area of Sahel, combining the traditional way of building houses with modern technology. The particularly analysed case, is the housing problem in the Republic of Chad. The author presents the basic discussion on this topic and his architectural proposals. Unfortunately, the gap between the needs and the financial feasibility of housing construction in this area, makes this project already at the starting point extremely difficult to be realized without external subventions.Problem mieszkaniowy w Afryce jest jednym z wyzwań, które należy rozwiązać, aby Afrykanie mogli odzyskać godność życiową i zabezpieczyć swoje prawa do tradycyjnego życia rodzinnego w akceptowalnych warunkach. W artykule opisano badania nad typowymi rozproszonymi strukturami miejskimi i potrzebą wspierania tego typu struktur osadniczych oraz propozycji wprowadzenia nowego systemu konstrukcji domów, opartym na lekkim szkielecie stalowym, łączącym tradycyjny sposób budowania domów z nowoczesną technologią. Przypadkiem szczególnie analizowanym jest problem mieszkaniowy w Republice Czadu. Autor przedstawia podstawową dyskusję na ten temat i swoje propozycje architektoniczne. Niestety luka między potrzebami mieszkaniowymi w Czadzie a finansową wykonalnością budownictwa mieszkaniowego w tym obszarze sprawia, że projekt ten, już w punkcie wyjścia, jest niezwykle trudny do realizacji bez uzyskania zewnętrznych dotacji

    Seeing the world anew : the radical vision of Martin Waldseemüller's 1507 & 1516 world maps /

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    9781929154470 (ISBN). 192915447X (ISBN). First edition 2012. Accompanied by 2 foldeds map in front and back pockets: 1507 map -- 1516 map.; Includes bibliographical references: pages 98-107.; Maps from pockets also available online http://nla.gov.au/nla.map-vn6254227; Original version of the 1507 map: Universalis cosmographiae secundum Ptholomaei traditionem et Americi Vespucii alioru que lustrationes. [St. Dié, France? : s.n., 1507]; Original version of the 1516 map: Carta marina, navigatoria Portugallen, navigationes atque tocius cogniti orbis terre marisque formam naturamq[u]e situs et terminos nostris temporibus recognitos et ab antiquorum traditione differentes eciam quor[um] vetusti non meminerunt auctores hec generaliter indicat / consumatum est in oppido S. Deodati compositione et digestione Martini Waldseemuller Ilacomili. [St. Dié, France? : s.n., 1516]. Prologue: In a Renaissance Vision, a Glimpse of the Modern / John W. Hessler -- "An island surrounded on all sides by sea" : The World Map, 1507 / John W. Hessler -- "Land of Cuba, part of Asia" : The Carta marina, 1516 / Chet Van Duzer -- Epilogue: A Renaissance That Resonates Still / John W. Hessler -- Notes -- Afterword / Ralph E. Ehrenberg -- About the authors -- Acknowledgments -- The Maps: The 1507 World Map, 12 sheets, with commentary -- Composite: front pocket -- The 1516 Carta marina, 13 sheets, with commentary -- Composite: back pocket

    Klimat społeczny w szkole inkluzyjnej

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    Author presented in this paper theoretical approach to the building of social climate in an inclusive school. The publication indicatessome tendencies and directions of changes to improve the functioning of these institutions and to implement the idea of inclusive education.Autorka przedstawiła w artykule teoretyczne ujęcie zagadnienia związanego z budowaniem klimatu społecznego w szkole inkluzyjnej. W publikacji ukazano pewne dążenia i kierunki zmian, jakich należy dokonywać w masowych szkołach, aby poprawić jakość funkcjonowania tych placówek, tak by kierowały się one ideą edukacji włączającej

    Ewolucja programowa FDP w polityce wschodniej w latach 1949-1969 w świetle nowych zasobów Archiwum Niemieckiego Liberalizmu

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    Zasadniczym celem artykułu jest analiza działalności programowej FDP w polityce wschodniej Republiki Federalnej Niemiec w latach 1949-1969. Autor wykorzystał nowe zasoby Archiwum Niemieckiego Liberalizmu w Gummersbach, co umożliwiło przedstawienie nowej oceny wpływu FDP na politykę wschodnią Republiki Federalnej Niemiec.The main goal of the article is to analyze the FDP's program activities in the eastern policy of the Federal Republic of Germany in the years 1949-1969. Of great importance here is the fact that the author used in this work new archives from the Archives of German Liberalism in Gummersbach. This enabled him to present a new assessment of the FDP's impact on the eastern policy of the Federal Republic of Germany

    Zasady szacowania gruntów w postępowaniach scaleniowych w Polsce

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    The subject of the study was the principles of land estimation used for the purpose of consolidation proceedings, as they are applied in Poland. The work examines the legal conditions relating to the estimation of land for the purposes of consolidation. Documents prepared in the years 2005–2017 concerning land estimation (resolutions of the consolidation participants, and protocols from the value estimates) have been collected for 41 consolidated sites, located in 28 districts of 11 voivodships (regions). A survey was conducted among the surveyors-designers of the consolidation proceedings, consisting of 19 questions. In the current year, the co-author of the present article was present at meetings of consolidation proceedings’ participants, convened in order to determine the rules for estimating land value on two sites located in different regions, and the material she collected during those meetings was used in the article. The collected data were subjected to an analysis, which showed that within Poland there is no homogeneity in the method of estimating land value for the purpose of consolidation proceedings, and that the method used to determine the value of land, taking into account the 1-hectare estimated rate, and the price of 1dt of rye grain, according to the provisions of the agricultural tax, is incompatible with the principles for the valuation of agricultural real estate, as specified in the law on real estate management.Przedmiotem badań były zasady szacowania gruntów stosowane w postępowaniach scaleniowych w Polsce. W ramach pracy przeanalizowano uwarunkowania prawne odnoszące się do szacunku gruntów na potrzeby scaleń. Zebrano dokumentację sporządzoną w latach 2005-2017 dotyczącą szacunku gruntów (uchwały uczestników scalenia i protokoły z przeprowadzonego szacunku) dla 41 obiektów scaleniowych, położonych na terenie 28 powiatów z 11 województw. Przeprowadzono ankietę wśród geodetów-projektantów scaleń, składającą się z 19 pytań. Współautorka artykułu w bieżącym roku była obecna na spotkaniach uczestników scalenia, zwołanych w celu ustalenia zasad szacowania gruntów na dwóch obiektach, zlokalizowanych w różnych województwach i zebrane materiały dotyczące tych spotkań wykorzystane zostały w artykule. Zgromadzone dane poddano analizie, która wykazała, że w Polsce nie ma jednolitości w sposobie szacowania gruntów na potrzeby postępowań scaleniowych oraz że stosowany sposób określania wartości gruntów z uwzględnieniem stawek szacunkowych 1 ha oraz ceny 1dt żyta wg przepisów o podatku rolnym jest niezgodny z zasadami wyceny nieruchomości rolnych określonymi w ustawie o gospodarce nieruchomościami

    Ograniczenia wolności słowa w Internecie

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    The development of Internet services lead to many changes in forms of expression of our opinions and ideas. The author shall discuss whether the term “freedom of speech” is still suitable for modern times, regarding the conversations in the social media. As we all know, the freedom of speech and the freedom of expression were never absolute and certain limitations of them are completely legal and necessary. However, as the author will try to prove, there are some serious concerns about executing such limitations online as well as effectively proving if someone’s rights have been violated due to excess of freedom of expression. The possible ideas of fighting the hate speech and other acts of trespassing the right to free expression shall also be presented.Rozwój usług Internetowych spowodował wiele zmian w sposobach wyrażania naszych opinii i pomysłów. Autor przeprowadzi rozważania odnośnie tego czy określenie “wolność słowa” jest wciąż adekwatne do współczesnych czasów, odnosząc się do rozmów w przestrzeni mediów społecznościowych. Powszechnie wiadomo, że wolność słowa i wolność wypowiedzi nigdy nie były absolutne i pewne ich ograniczenia są całkowicie legalne oraz konieczne. Jednakże, jak autor spróbuje wykazać, istnieją poważne wątpliwości odnośnie wykonalności takich ograniczeń w sieci, a także efektywnego dowodzenia, że cudze prawa zostały naruszone w związku z przekroczeniem granic wolności wypowiedzi. Propozycje możliwych rozwiązań w walce z mową nienawiści i innymi przejawami przekraczania prawa do wolności wypowiedzi także zostaną zaprezentowane

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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