3,962 research outputs found
Avian MHC: variation and selection in the wild
No full textIn vertebrates the Major Histocompatibility Complex (MHC) plays a central role in the specific immune defence against various pathogens. Compared with other coding genes the MHC genes exhibit an extremely high level of polymorphism that is maintained by balancing selection. The importance in the immune defence and the polymorphism make these genes interesting to study from an ecological and evolutionary perspective in populations subject to natural selection. In my thesis I have studied MHC in a population of wild songbirds, great reed warblers Acrocephalus arundinaceus. Firstly, I characterized parts of the MHC class I and II genes and I focused especially on transcribed genes since these are likely to be under selection. Then I developed a PCR-based screening method for investigating the MHC class I polymorphism in our study population. In the great reed warbler genome there was a large number of MHC class I and II genes and there was also evidence of balancing selection in these genes. There was a surprisingly high level of variation in the MHC genes in the great reed warblers within the study population considering the limited variation that have been detected using neutral markers. Secondly, I searched for evidence of selection on the MHC genes and for associations between life-history data and MHC genes. I found evidence that there is selection on the MHC class I alleles in great reed warblers. Avian malaria could be one such selective force since great reed warblers that had a large number of MHC alleles (heterozygous individuals) survived an infection with avian malaria (GRW2) more often than individuals with fewer MHC alleles. Hence, a large number of MHC alleles seem critical for survival. However, we did not find that MHC-compatibility is involved in female mate choice in the great reed warblers, as has been found in humans and mice, despite the fact that more MHC heterozygous great reed warbler siblings do survive more often. Finally, associations between certain MHC alleles, or a large number of MHC alleles, and resistance to specific diseases have so far been found in a handful of species. Most of these associations involve humans or are experiments that have been done under controlled conditions. To me it is compelling that the selection pressure from pathogens on MHC genes can be visualised also under natural conditions in wild populations, as e.g. the great reed warblers
Helena Kolody, carbono & diamante: uma biografia ilustrada
No full textTese (doutorado) - Universidade Federal de Santa Catarina, Centro de Comunicação e Expressão. Programa de Pós-Graduação em LiteraturaHelena Kolody, carbono & diamante - uma biografia ilustrada conta a vida da escritora Helena Kolody, a partir de sua inscrição na literatura, questionando sua identidade, o mundo que a cercava e o sentido de sua existência. Equivale a dizer: em sua lírica, reflexões e sentimentos se entretecem a partir de uma matéria pessoal e localizada. Da estação ferroviária à estação tubo; da Ucrânia ao centro de Curitiba; de Paisagem interior a Reika; do século XIX ao século XXI, a literatura de Helena Kolody gerencia sua presença na consolidação do binômio arte-vida. O retrato da autora acaba se constituindo também por meio de farto aparato iconográfico; pelos mais de quinhentos textos críticos elencados e por sua obra completa. Fragmentação deliberadamente assumida, a pessoa se revela em sua inteireza.Helena Kolody, carbon & diamond - an illustrated biography tells the life of Helena Kolody, from her very insertion in literature, as it questions her identity, the world surrounding her, and the meaning of her existence. That is equivalent to saying that in her poetry there is the intermingling of reflections and feelings that derive from personal and localized material. From the railroad station to the tube-shaped bus stops; from Ukraine to downtown Curitiba; from Paisagem interior to Reika; from the nineteenth century to the twenty-first century, Helena Kolody's literature guarantees her presence in the consolidation of the art/life binomial. The portrait of the author ends up by also being made up of an abundant iconographic apparatus, of the over five hundred critical texts listed, and of her complete work. The person, although deliberately accepting her own fragmentation, reveals herself in her entireness
Avian MHC: variation and selection in the wild
No full textPopular Abstract in Swedish Trastsångarnas MHC gener i klarspråk Inuti kroppen ser vi väldigt lika ut allihop; men om mina njurar skulle sluta att fungera är det inte alls säkert att just du kan donera en njure till mig. Detta beror på att våra transplantations-gener eller s.k. MHC- (Major Histocompatibility Complex) gener är olika, och vid en transplantation måste många av donatorns och mottagarens MHC-gener vara identiska. En gen är ett arvsanlag som finns i vår arvsmassa. Varje gen finns i två upplagor (en från mamma och en från pappa) och dessa kallas alleler (figur 1). Informationen i generna översätts och därför blir du t.e.x. lik din mamma, du har ju fått hälften av dina gener från henne. MHC-genernas uppgift är givetvis inte att tala om ifall vi kan donera njurar till varandra eller inte, utan det är en sidoeffekt av att de har en mycket viktig roll i vårt immunförsvar. MHC-generna finns hos alla ryggradsdjur och ser i stora drag lika ut hos alla arter. Det speciella med MHC-generna är att det finns extremt många olika alleler för de här generna. MHC-generna bildar MHC-molekyler som hjälper kroppens immunförsvar att känna igen vad som är kroppens egna celler och vad som är virus och bakterier. När MHC-molekylen hittar små protein-bitar som inte är kroppsegna aktiveras kroppens immunförsvar och oskadliggör viruset / bakterien. En MHC-molekyl kan hitta ett begränsat antal varianter av protein-bitar och därför är det ofta fördelaktigt att ha många olika MHC-molekyler i kroppen (se figur 1 i den engelska sammanfattningen). Jag har studerat MHC-generna i en liten brun sångfågel som heter trastsångare. Den häckar i vassområden i Mellansverige och övervintrar i Västafrika. Det speciella med trastsångarna, som vi studerar i sjön Kvismaren i Närke, är att deras häckningsekologi har följts under 20 års tid. Därför har vi en enorm kunskapsbank om trastsångarnas släktskap, öden och äventyr vid den här sjön. Trastsångarna visade sig ha många MHC-gener, minst åtta stycken, vilket kan jämföras med tamhöns (den fågelart där MHC-generna är mest välstuderade) som har två stycken. I mitt doktorandprojekt utvecklade jag en molekylärgenetisk metod för att kunna studera MHC-generna hos trastsångare. Jag ville ta reda på ifall trastsångare med många MHC-alleler, eller speciella MHC-alleler, överlevde bättre än andra. Dessutom undrade jag hur olika trastsångarnas MHC-alleler är. Den molekylära metoden som jag har använt för att studera MHC-generna fångar upp 2-12 MHC-alleler ifrån varje individ. Individer med få MHC-alleler (2 stycken) har mindre variation i sina MHC-gener jämfört med individer men många MHC-alleler (12 stycken). Hos trastsångarna i Kvismaren har nästan alla individer olika kombinationer av MHC-alleler, vi hittade 234 unika kombinationer av MHC-alleler i 248 individer. Ytterligare ett starkt bevis för att MHC-generna är variabla hos småfåglar fick jag när vi studerade MHC-variationen hos Seyshellsångaren, en liten släkting till trastsångaren där alla individer är nära besläktade med varandra. Det fanns naturligtvis total sätt färre MHC-alleler hos Seyshellsångaren jämfört med trastsångaren, men variationen mellan MHC-allelerna var lika stor hos båda arterna; d.v.s. en Seyshellsångare med två MHC-alleler bör kunna skydda sig lika bra mot olika sjukdomar som en trastsångare med två MHC-alleler. Jag nämnde tidigare att det kan vara fördelaktigt att ha många olika MHC-molekyler i kroppen eftersom det gör att man kan skydda sig mot fler sjukdomar. I en tidigare trastsångarstudie har man studerat hur par av trastsångarsyskon överlever sin första vinter och funnit att syskonet med störst variation i sina gener överlever oftare. När vi undersökte om den genetiska variationen i MHC-generna hade betydelse för överlevnad så pekade resultatet i samma riktning, d.v.s. syskonet med mest flest MHC-alleler överlevde oftare. Om man som mamma vill ge sina barn en stor genetisk variation i MHC-generna så ska man välja en pappa som har annorlunda MHC-alleler än vad man själv har. Man har faktiskt visat att precis så här kan det gå till hos människor och möss, mammor väljer att få barn med pappor som har annorlunda MHC-alleler än vad de själva har. Frekvensen av spontana aborter minskar om mamman och pappan har olika MHC-alleler och troligtvis används luktsinnet när mamman väljer ut sin partner. Jag undersökte om även trastsångarhonorna valde ut sina partners baserat på MHC-alleler, men det gjorde de inte. Trastsångarhonor tycker att välsjungande äldre hanar som är bosatta i vassruggar av hög status är mest attraktiva! Många sjukdomar i naturen kommer och går, vissa år är de vanliga och andra ovanliga. Olika arter av fågelmalaria, som drabbar trastsångare, varierar exempelvis över tiden. Många trastsångare blir smittade av fågelmalaria i Afrika och en stor andel dör där under sin första vinter. De häckande trastsångare som vi studerar i Kvismaren är de som har överlevt vintervistelsen i Afrika. Även vilka MHC-alleler som är vanliga varierar över tiden bland fåglarna i Kvismaren. Eftersom både vilka arter av fågelmalaria och vilka MHC-alleler som är vanligast varierade mellan år så undersökte vi om de samvarierade. Vi hittade ett samband mellan en speciell MHC-allel och en art av fågelmalaria och vi tolkade sambandet som att den speciella MHC-allelen var en ”överlevar-allel”. Vi fann dessutom ett samband mellan antalet MHC-alleler och ovannämnda art av fågelmalaria, d.v.s. det var större sannolikhet att man överlevde en infektion med fågelmalaria om man hade många MHC-alleler. Nyligen läste jag en översiktsartikel som handlade om 15 års studier av MHC i icke-modellorganismer (d.v.s. alla organismer utom mus och människa). Trots att MHC är svårt och komplext att studera så var slutklämmen i artikeln att MHC är det bästa systemet som finns tillgängligt för att studera samband mellan krafter i naturen (exempelvis sjukdomar) och gener. Man har funnit samband mellan sjukdomsresistens och MHC-gener hos människor, får, fiskar och kyckling; och med den här studien även hos trastsångare (fågelmalaria). Därmed finns det ett samband mellan MHC-gener och sjukdomsresistens rapporterat även från en vild fågel-population.In vertebrates the Major Histocompatibility Complex (MHC) plays a central role in the specific immune defence against various pathogens. Compared with other coding genes the MHC genes exhibit an extremely high level of polymorphism that is maintained by balancing selection. The importance in the immune defence and the polymorphism make these genes interesting to study from an ecological and evolutionary perspective in populations subject to natural selection. In my thesis I have studied MHC in a population of wild songbirds, great reed warblers Acrocephalus arundinaceus. Firstly, I characterized parts of the MHC class I and II genes and I focused especially on transcribed genes since these are likely to be under selection. Then I developed a PCR-based screening method for investigating the MHC class I polymorphism in our study population. In the great reed warbler genome there was a large number of MHC class I and II genes and there was also evidence of balancing selection in these genes. There was a surprisingly high level of variation in the MHC genes in the great reed warblers within the study population considering the limited variation that have been detected using neutral markers. Secondly, I searched for evidence of selection on the MHC genes and for associations between life-history data and MHC genes. I found evidence that there is selection on the MHC class I alleles in great reed warblers. Avian malaria could be one such selective force since great reed warblers that had a large number of MHC alleles (heterozygous individuals) survived an infection with avian malaria (GRW2) more often than individuals with fewer MHC alleles. Hence, a large number of MHC alleles seem critical for survival. However, we did not find that MHC-compatibility is involved in female mate choice in the great reed warblers, as has been found in humans and mice, despite the fact that more MHC heterozygous great reed warbler siblings do survive more often. Finally, associations between certain MHC alleles, or a large number of MHC alleles, and resistance to specific diseases have so far been found in a handful of species. Most of these associations involve humans or are experiments that have been done under controlled conditions. To me it is compelling that the selection pressure from pathogens on MHC genes can be visualised also under natural conditions in wild populations, as e.g. the great reed warblers
Transient observations : the textualizing of St Helena through five hundred years of colonial discourse
No full textThis thesis explores the textualizing of the South Atlantic island of St Helena (a
British Overseas Territory) through an analysis of the relationship between
colonizing practices and the changing representations of the island and its
inhabitants in a range of colonial 'texts', including historiography, travel writing,
government papers, creative writing, and the fine arts.
Part I situates this thesis within a critical engagement with post-colonial
theory and colonial discourse analysis primarily, as well as with the recent
'linguistic turn' in anthropology and history. In place of post-colonialism's rather
monolithic approach to colonial experiences, I argue for a localised approach to
colonisation, which takes greater account of colonial praxis and of the continuous
re-negotiation and re-constitution of particular colonial situations.
Part II focuses on a number of literary issues by reviewing St Helena's
historiography and literature, and by investigating the range of narrative tropes
employed (largely by travellers) in the textualizing of St Helena, in particular
with respect to recurrent imaginings of the island in terms of an earthly Eden.
Part III examines the nature of colonial 'possession' by tracing the island's
gradual appropriation by the Portuguese, Dutch and English in the sixteenth and
early seventeenth century and the settlement policies pursued by the English
East India Company in the late seventeenth and early eighteenth century.
Part IV provides an account of the changing perceptions, by visitors and
colonial officials alike, of the character of the island's inhabitants (from the late
eighteenth to the early twentieth century) and assesses the influence that these
perceptions have had on the administration of the island and the political status of
its inhabitants (in the mid- to late twentieth century).
Part V, the conclusion, reviews the principal arguments of my thesis by
addressing the political implications of post-colonial theory and of my own
research, while also indicating avenues for further research.
A localised and detailed exploration of colonial discourse over a period of
nearly five hundred years, and a close analysis of a consequently wide range of
colonial 'texts', has confirmed that although colonising practices and
representations are far from monolithic, in the case of St Helena their continuities
are of as much significance as their discontinuities
Helena Więckowska’s activity as a director of the Library of the Łódź University
No full textProfesor Helena Więckowska (1897–1984) była z pewnością jedną z najbardziej znaczących postaci w polskim bibliotekarstwie, w okresie powojennym. Wniosła także istotny wkład w rozwój polskiej bibliologii i wydatnie przyczyniła się do ukształtowania systemu akademickiego kształcenia bibliotekarzy. Bibliografia Jej dorobku naukowego liczy 221 pozycji. Są w nim rozprawy, artykuły, recenzje, hasła w słownikach i encyklopediach. Jest to również dorobek zróżnicowany tematycznie, co potwierdza trafność określenia „bibliolog praktyk”, użytego wobec dokonań Profesor Więckowskiej przez Krzysztofa Migonia.The author of the article discusses the activities of Helena Więckowska – the second in the order director of the Library of the Łódź University. In the text you can find information about the problems that she as a director had to face: first of all with the facilities but also with the development of collections. The author mentiones that Helena Więckowska cared very much about the vocational training of employees: improving the librarians’ qualifications, gaining degrees. In 1954 she decided to train students in the field of using the library. She retired in 1969 – after 21 years as a director of the university’s library.Publikacja współfinansowana przez Bibliotekę UŁ oraz Wydział Filologiczny UŁ
Franciszek Kostrzewski, warszawska publiczność i Helena Modrzejewska
No full textThe article describes a little-known collage documenting the huge success of Helena Modrzejewska’s first guest performances in Warsaw in October and November of 1868. The author of the Benefis Heleny Modrzejewskiej (a collage kept in the collection of the National Museum in Warsaw) is Franciszek Kostrzewski. This excellent cartoonist and “pencil humorist” presented a triumphant procession of the actress’ admirers. He used a then fashionable technique of combining satirical drawings with pasted fragments of photographs. The participants of the ceremonial procession include mainly representatives of the Warsaw press and theatre scene. The author of the article tried to decipher the people portrayed. She managed to identify and describe nearly 30 people who participated in this extraordinary event, which was Modrzejewska’s Warsaw debut
Helena Więckowska in the pages of “The Dictionary of the Polish Book Labourers”
No full textProfesor Helena Więckowska (1897–1984) była z pewnością jedną z najbardziej znaczących postaci w polskim bibliotekarstwie, w okresie powojennym. Wniosła także istotny wkład w rozwój polskiej bibliologii i wydatnie przyczyniła się do ukształtowania systemu akademickiego kształcenia bibliotekarzy. Bibliografia Jej dorobku naukowego liczy 221 pozycji. Są w nim rozprawy, artykuły, recenzje, hasła w słownikach i encyklopediach. Jest to również dorobek zróżnicowany tematycznie, co potwierdza trafność określenia „bibliolog praktyk”, użytego wobec dokonań Profesor Więckowskiej przez Krzysztofa Migonia.The article aim to provide a view on the relations between prof. Helena Więckowska and the works on the formation of the “Dictionary of Polish book labourers”. Her contribution to the construction of the “Dictionary...” is discussed, she was the author of biographies of people who are considered precursors of Polish Library Science and creators of current theoretical trends in the discipline (J. Lelewel, J. Grycz, J. Muszkowski), as well as biographies of the owners, creators, and librarians (A. Lewak, brothers B. and W. Niemojowski, A. Ostrowski). The dictionary contains biographical notes of librarians and LIS researchers – participants of seminars conducted by H. Więckowska during her many years of teaching in Warsaw and Łódź.Publikacja współfinansowana przez Bibliotekę UŁ oraz Wydział Filologiczny UŁ
Helena Syrkus through the lens of her correspondence
No full textThe thesis will elaborate Helena and Szymon Syrkus’ connection with the “Congress of Modern Architecture” (CIAM). It will investigate in what ways the Polish couple has brought Modernist ideas to Poland and put a special emphasis on the work of Helena Syrkus.The point of focus will lay on how the Helena Syrkus could manage to keep in touch with the most influential architects of the 20th century and how her social skills and fluent knowledge of multiple languages (English, German, French) enabled her to become an influential female architect. She became friends with Walter and Ise Gropius, Cornelis van Eastern, and Frieda Fluck as well as Marcel Breuer, Siegfried Giedion and many others. Her correspondence became an important medium for her work as she shared her career plans and information about her recent projects. Thus, the research question is in a great part inspired by her vast correspondence network, where she reigned unchallenged. In a private letter to her sister, Syrkus makes it apparent that her typewriter was an integral item without which she would only depart for holidays. In any other case, a full-size or pocket typewriter would constantly be at her side. This special relationship that was prominent in Syrkus’ life gave impetus to the research question:Has Helena Syrkus’ typewriter become a passport of Modernism to Polish architecture?AR2A011Architecture, Urbanism and Building Science
Health Hazard Evaluation Report: HETA-93-0028-2366: West Helena - Helena Sportswear, Inc.; West Helena, Arkansas
No full textIn response to an employee request, an investigation was begun into possible health effects resulting from formaldehyde (50000) exposure at West Helena-Helena Sportswear (SIC-2337), West Helena, Arkansas. The company manufactured ladies' sportswear. Precured permanent press fabrics were spread on large tables and cut to patterns. Pieces were fused, bundled, and tagged. The cut pieces were then assembled into garments which were pressed, inspected, bagged, and shipped. About 1,000 finished garments were produced each day. Personal breathing zone formaldehyde concentrations ranged from 0.14 to 0.17 parts per million (ppm) as an 8-hour time weighted average (TWA). General area sample formaldehyde concentrations ranged from 0.16 to 0.25ppm as an 8-hour TWA, and particulate concentrations ranged from 0.02 to 0.15mg/m3. The dust was found to contain formaldehyde. The formaldehyde levels in personal breathing zone and general air samples exceeded the NIOSH Recommended Exposure Limit of lowest feasible concentration. The author concludes that the formaldehyde concentrations exceeded the NIOSH recommended limit. Nuisance dust evaluation criteria may not be sufficient since the dust contained formaldehyde. The author recommends that efforts be made to reduce formaldehyde exposures at this facility
Passerine MHC: genetic variation and disease resistance in the wild
No full textThe passerine major histocompatibility complex (MHC) class I and IIB genes are different from those of the avian model species the chicken because passerines have (1) a larger number of MHC genes, (2) MHC genes with longer introns, and (3) MHC genes that are pseudo-genes. Most passerine MHC genes are transcribed (coding), extremely variable and subject to balancing selection. The high genetic diversity of the MHC genes of passerines is most likely maintained by selection from a large number of different pathogens. Association between MHC alleles and resistance to avian malaria infections have been reported in House Sparrows and Great Reed Warblers. Passerines are infected by a large number of different avian malaria infections. Therefore passerines and avian malaria is a study system that is well-suited to investigations of balancing selection and associations between MHC genes and disease resistance
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