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The major aim of this work has been to gain further insights into the catalytic mechanism of carbonic anhydrase (carbonate hydro-lyase, EC 4.2.1.1). One approach has been to replace the essential Zn(II) ion by Cd(II) which has favourable spectroscopic properties. The Cd(II)-enzymes have appreciable 4-nitrophenyl acetate hydrolase activities. These activities increase with pH as if dependent on the basic form of a group with pKa near 10. The Cd(II)-carbonic anhydrases also have significant carbon dioxide hydration activities. Jhe Cd(II) derivatives are strongly inhibited by monovalent anions. The 113-Cd(II) derivatives have also been studied by 113-Cd NMR as a function of pH and bicarbonate or inhibitor concentration. Plots of chemical shift versus pH give sigmoidal titration curves in the studied pH range, 10.3. The p«a values vary from 9.2 to 9.7 correlating reasonably well with the activity profiles. When bicarbonate is added to the samples the 113-Cd resonances shift upfield to new characteristic positions. The inhibitors CN", SH", and SCN” bind directly to the metal ion with their C, S, and N atoms, respectively. The results are best explained by assuming a rapid exchange between three species in which the open coordination site of the metal ion is occupied by'hydroxide, water, or bicarbonate. Another approach has been to study kinetic properties of the active en­zyme. A number of monovalent anions were investigated as inhibitors of carbon dioxide hydration catalyzed by human carbonic anhydrase II. Predominantly uncompetitive inhibition patterns were observed at pH near 9 in all cases. The inhibition of human carbonic anhydrase II by the organic compounds tetrazole, 1,2,4-triazole, 2-nitrophenol, and chloral hydrate was also investigated. These inhibitors, together with phenol, can be classified in three groups depending upon the kinetic patterns of inhibition of carbon dioixde hydration at pH near 9. The first group, represented by tetrazole and 2-nitrophenol, yields predominantly uncompetitive inhibition under these conditions in analogy with simple, inorganic anions. The second group, represented by 1,2,4-triazole and chloral hydrate gives rise to essentially noncompetitive inhibition patterns whereas phenol, representing the third group, is a competitive inhibitor of carbon dioxide hydration. These results are analyzed in terms of two rivaling mechanism models, a kinetic scheme originally proposed by Steiner et al. (Eur. 3. Biochem. (1975) 59, 253-259) and a rapid-equilibrium kinetic scheme proposed by Pocker and Deits (3. Am. Chem. Soc. (1982) 104, 2424-2434). It is concluded that the observed steady-state inhibition patterns are compatible with both models, but hat discriminatory data, strongly favouring the model of Stêiner et al., are available in the literature. / <p>Diss. (sammanfattning) Umeå : Umeå universitet, 1984, härtill 4 uppsatser</p> / digitalisering@umu

Norint ištirti vario (Cu) ir kadmio (Cd) įtaką augalams, augintiems skirtingose terpėse, buvo vertinamas diferencijuotas ir kompleksinis sunkiųjų metalų poveikis jų morfologiniams ir fiziologiniams rodikliams. Varis reikalingas mažais kiekiais kaip mitybos elementas, bet tampa toksišku esant didesnėms jo koncentracijoms aplinkoje. Kadmis neturi biologinės funkcijos ir gali būti toksiškas esant mažoms koncentracijoms, priklausomai nuo aplinkos sąlygų, jo cheminio būvio ir t.t. Tyrimo objektais buvo pasirinkti vasariniai miežiai (Hordeum vulgare L.) ir mažosios plūdenos (Lemna minor). Šio darbo tikslas yra įvertinti ir palyginti Cd ir Cu poveikį esant skirtingam biologiniam prieinamumui iš vandeninės terpės ir dirvožemio. Tiriamas darbas buvo atliekamas dviem etapais. Visų pirma buvo tiriamas pavienis metalų poveikis Lemna minor. Savaitę jos buvo auginamos 0,1 µM; 0,5 µM; 1 µM; 10 µM; 50 µM ir 100 µM koncentracijos kadmio bei 1 µM; 5 µM; 10 µM; 50 µM ir 100 µM koncentracijos vario tirpaluose. Metalų mišinių koncentracijos, kuriomis buvo veikiamos Lemna minor, pasirinktos pagal diferencituotas, kuriose augalai išgyveno daugiau kaip pusę tiriamojo laikotarpio. Nustačius EC50 koncentracijas pagal tiriamojo parametro, lyginant su kontrole, sumažėjimą, apskaičiuota EC50 mišinio. Mišinio koncentracijos išreikštos kaip TU. Įvertinti Lemna minor biomasės prieaugio, augimo inhibicijos pokyčiai. Kompleksinio poveikio atveju augimo greičiui (EC50 mišinio = 2,5 TU) ir biomasės... [toliau žr. visą tekstą] / The aim of this study was to investigate the influence of cadmium (Cd) and copper (Cu) to plants froms diferent growing medium and evaluate the single and combined effect to their morphologic and physiologic parameters. Cu is known as micronutrient. It is necessary for plants but becames toxic at higher concentrations. Cd doesn‘t have any biological function and can be toxic even at small concentrations. It‘s toxicity depends on environmental conditions, chemical state and etc. The subject of this research is agricultural plants summer barley (Hordeum vulgare L.) and water plants duckweed (Lemna minor). The purpose of study is to value and to compare Cd and Cu effects to plants from water and soil medium. The research was done in two stages. At first, the single heavy metal effect to Lemna minor was investigated. Plants were treated one week by 0,1 µM; 0,5 µM; 1 µM; 10 µM; 50 µM; 100 µM Cd and 1 µM; 5 µM; 10 µM; 50 µM; 100 µM Cu concentrations. Considered to single concentrations, combained concentrations were chosen. Concentrations in the mixtures was expressed as TU, as fraction of their median affective concentration (EC50). Biomass and growing inhibition were measured. Antagonistic responses to biomass (EC50 mix = 2 TU) and growth inhibition (EC50 mix = 2,5 TU) occurred with Cd+Cu mixture. The experiment was also done with summer barley (Hordeum vulgare L.). Two weeks they were grown in soil and water solutions affected by the same heavy metal concentrations like Lemna... [to full text]

Diplomová práce Educational set of microscopic anatomy of intervertebrates for secondary schools. Tomáš Bartáček Pedagogická fakulty UK v Praze 2010 In this thesis, I compiled an educational set illustrating the microscopic anatomy of intervertebrates. This set is intended for use by students and teachers at high schools and gymnasia. It complements the common tools used for education in zoology of invertebrates. It combines a set of microscopic specimens (histological sections, smear and native specimens) and multimedia atlas. For the present work, I chose model invertebrates that have been commonly described in high school and gymnasia text books. For preparation of the histological sections, I used flatworms (Dugesia gonocephala), roundworms (Ascaris suum) and earthworms (Lumbricus terrestris). I prepared the specimens in accordance with standard methods shown in literature with slight modifications in order to make them suitable for the given specimens. I used paraffin as a cutting fluid and I stained the specimens using either Harris hematoxylin and eosin or Masson's trichrome stain. To create the smear specimens, I spread the animal tissues of interest, fixed them in methylene and stained using Giemsa-Romanowski stain. I prepared the native specimens both vital stained and non-stained. I...

En cas d’accident grave dans un réacteur nucléaire à eau sous pression, l’alliage absorbant Ag-Cd-In est susceptible d’interagir à haute température avec leurs tubes guides en zircaloy. L’étude thermodynamique du liquide et des équilibres impliquant cette phase dans les systèmes Ag-Zr et Ag-Cd-In est une étape pour une estimation des relâchements de produits de fission. Le système Ag-Zr est difficile à étudier en raison de la réactivité du zirconium, à l’état liquide et avec l’oxygène, et de la difficulté à atteindre l’équilibre et enfin car les stabilités des phases intermédiaires AgZr et AgZr2 sont faibles. Après la mise en place de protocoles expérimentaux, les réactions invariantes du système sont établies en couplant l’analyse thermique différentielle avec des caractérisations par MEB. Un diagramme de phases Ag-Zr est proposé. Des mesures de calorimétrie de dissolution en bain aluminium sont effectuées à 723°C dans le but de déterminer l’enthalpie de formation de AgZr et AgZr2. Les résultats montrent la difficulté de dissoudre le zirconium dans l’aluminium liquide. Un modèle est développé pour quantifier la cinétique de dissolution. L’enthalpie de formation de AgZr est déterminée par calorimétrie de dissolution en bain acide à 25°C. L’extension dans le diagramme Ag-In-Cd du domaine de stabilité de la phase liquide est précisée en combinant une méthode isotherme de recuit et trempe d’échantillons biphasés solide/liquide avec la calorimétrie différentielle à balayage . La cohérence de ces nouveaux résultats entre eux et avec les données de la littérature est testée par le biais d’une optimisation thermodynamique suivant la méthode CALPHAD. / During a severe accident in a Pressurized Water Reactor, the Ag-In-Cd absorbing alloy is likely to interact at a high temperature with their guide tubes or with the fuel rod cladding, both in Zry. The thermodynamic study of liquid phase and its equilibria in the Ag-Zr and Ag-Cd-In systems is a necessary step for an estimate of the fission product release and of the corium progression. The aim is to bring an experimental contribution to this thermodynamic study. The Ag-Zr system is difficult to study experimentally for various reasons. Zirconium, especially when liquid, is reactive with oxygen. Equilibria often prove difficult to reach. Last, the stabilities of AgZr and AgZr2 are low. After the establishment of experimental protocols, the invariant transformations of the system were established by coupling differential thermal analysis with characterization by metallography and scanning electron microscopy. A Ag-Zr phase diagram is proposed. Solution calorimetry measurements in an Al bath were performed at 723°C to determine the enthalpy of formation of AgZr and AgZr2. Results show the difficulty of dissolving solid zirconium in aluminum. A model was developed to quantify the dissolution kinetics. The formation enthalpy of AgZr was determined by solution calorimetry in an acid bath at 25°C. In the Ag-In-Cd system, the extension of the liquid phase stability domain is specified by combining an isothermal method of annealing and quenching of biphasic solid / liquid samples with differential scanning calorimetry. The consistency of the new results between them and compared to the literature has been tested by means of a thermodynamic optimization following the CALPHAD method.

Septinas compreendem uma conservada família de proteínas de ligação a nucleotídeo de guanina e formação de heterofilamentos. Em termos estruturais, elas possuem uma organização comum: um domínio GTPase central, uma região N-terminal e um domínio C-terminal, este último é predito para formar estruturas em coiled coil. Atualmente, o heterocomplexo de septinas humanas (SEPT2/SEPT6/SEPT7) mais bem caracterizado revela a importância do domínio GTPase na formação do filamento, todavia a ausência de densidade eletrônica para os domínios C-terminais faz com que sua função permaneça obscura. Estudos com septinas de mamíferos, e de outros organismos como C. elegans e S. cerevisea sugerem que alguns grupos de septinas (por exemplo, II e IV em mamíferos) interagem através de seus domínios C-terminais, e estes poderiam atuar de modo determinante para a montagem correta do filamento. Assim, o presente projeto objetivou estudar a afinidade homo/heterotípicas para os domínios C-terminais das septinas humanas dos grupos II (SEPT6C/8C/10C/11C) e IV (SEPT7C), investigando se esses domínios contribuem para preferência das septinas interagirem com proteínas de grupos distintos durante a formação do heterofilamento. Os domínios C-terminais foram expressos em E. coli e purificados. Foram conduzidos estudos de ultracentrifugação analítica e espectropolarimetria de dicroísmo circular, que permitiram identificar maior afinidade e estabilidade da associação heterotípica comparada à homotípica. Foram obtidas constantes de dissociação aparente para homodímeros em torno de baixo &micro;M, enquanto que para heterodímeros os dados já existentes no grupo revelaram constante de dissociação na ordem de nM. Para entender os fatores no nível atômico responsáveis pela significativa predileção na interação entre os domínios C-terminais dos grupos II e IV foram realizados estudos utilizando modelagem e análise das sequências primárias. As análises sugerem a presença de um alto número de resíduos carregados na posição a do coiled coil como responsável pela seletividade. Consequentemente, o heterodímero seria favorecido em virtude do menor efeito repulsivo proveniente do intercalamento dos resíduos carregados em a. Desse modo, os resultados indicaram a atuação decisiva ou cooperativa dos domínios C-terminais na organização preferencial das septinas durante a formação do filamento, favorecendo a interface NC entre septinas dos grupos II e IV. / Septins comprise a conserved protein family that binds guanidine nucleotide and forms heterofilaments. In structural terms they have a common organization: a central GTPase domain, a N-terminal domain and a C-terminal domain, this last one is predicted to form coiled coil structures. Currently, the human septin heterocomplex best characterized (SEPT2/SEPT6/SEPT7) reveals the importance of the GTPase domain in filament assembly, however the absence of electron density for the C-terminal domains makes its function still unknown. Studies with mammals septins, and of others organisms like C. elegans and S. cerevisea suggests that some septins groups (e.g. II e IV in mammals) interact via its C-terminal domains and this could act in a determinative way to correct filament assembly. In this way, this project aimed to study the homo/heterotypical affinity for the C-terminal domains of human septins belonging to groups II (SEPT6C/8C/10C/11C) e IV (SEPT7C), investigating whether this domain contributes with the preference of septins to interact with proteins of different groups during assembly of the heterofilament. The C-terminal domains were expressed in E. coli and purificated. It was carried out studies using analytical ultracentrifugation and circular dichroism spectropolarimetry tecniques which allowed identification of major affinity and stability in the heterotypical association compared to homotypical. It was measured apparent dissociation constants for homodimers of low &micro;M range while for heterodimers our group\'s data shows dissociation constants in the nM range. To understand at atomic level the factors responsible for this significant preference in the C-terminal domains interaction between groups II and IV was performed molecular modelling studies and analysis of the primary sequence. These analysis suggests the presence of a high number of charged residues in position a of the coiled coil as responsible for selectivity. Consequently, the heterodimer would be therefore favoured because of the minor repulsive effect coming from the staggered of charged residues in a. Thus, these results indicate the crucial or cooperative action of C-terminal domains in preferential organization of septins during filament assembly, favouring the NC interface between septins of groups II and IV.

Master thesis studying the use of multimedia on CD-ROM in a library setting by analysis ofqualitative interviews with nineteen persons.The thesis relates the study to some relevant issues in human-computer interface (HCI) researchand to the commercial market for multimedia CD-ROM products. Three main types ofuse were described by the persons interviewed: recreational, information seeking and usingmultimedia to learn more about using computers. Children and young people interviewed mademost use of the multimedia provided, whereas adults thought it to be less valuable as a sourceof knowledge for them personally.HCI research shows various results of using multimedia for educational purposes. Thecommercial market is dominated by American products which can have a negative effect onthe use of multimedia in Swedish public libraries.

Made available in DSpace on 2017-07-10T17:36:52Z (GMT). No. of bitstreams: 1 Tatiane_Pauly.pdf: 986474 bytes, checksum: edb5179048924602bc98f262392d5036 (MD5) Previous issue date: 2013-08-28 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The objective of this study was to evaluate, in two cultivars of wheat agronomic characteristics and technological quality of flour depending on the spacing. The experimental design was a randomized block with four replications in a 4 x 2 factorial, with the first factor refers to the spacing (20 cm, 28 cm, 36 cm end 40 cm) and the second factor refers cultivars (CD 150 and BRS Tarumã). The experiment was set up in Santa Tereza do Oeste/PR in May 2011 and the crop was harvested at 126 DAE for cultivar CD 150 and 168 DAE for BRS Tarumã. The yield and grain moisture were reduced with increasing spacing 3.98% and 26.18% respectively. The hectolitre weight, the thousand grain weight, moisture of flour, ash dry basis, falling number and flour color were not affected by increasing spacing. The cultivar CD 150 showed lighter color, higher hectolitre weight, less ash and fewer drop compared to BRS Tarumã / O objetivo deste trabalho foi avaliar, em duas cultivares de trigo as características de interesse agronômico e a qualidade tecnológica da farinha em função do espaçamento entre linhas. O delineamento experimental utilizado foi o de blocos casualizados com 4 repetições em esquema fatorial 4 x 2, sendo que, o primeiro fator refere-se ao espaçamento entre linhas (20 cm, 28 cm, 36 cm e 40 cm) e o segundo fator refere-se as cultivares (CD 150 e BRS Tarumã). O experimento foi instalado em Santa Tereza do Oeste/PR em maio de 2011 e a colheita foi realizada aos 126 DAE para a cultivar CD 150 e 168 DAE para a cultivar BRS Tarumã. A produtividade e a umidade de grãos foram reduzidas com o aumento do espaçamento em 3,98% e 26,18% respectivamente. O peso hectolitro, a massa de mil grãos, a umidade da farinha, o teor de cinzas base seca, o número de queda e a cor da farinha não foram influenciados pelo aumento do espaçamento entre linhas. A cultivar CD 150 apresentou cor mais clara, maior peso hectolitro, menor teor de cinzas e menor número de queda em relação à BRS Tarumã

Smithhaven--Still Making Excuses--If Seeing Is Believing--Myth--Your Last Ride--If I Had a Dollar--Tack and Jibe--Stewie Took My Nose--March Home to Me--I Recall--God's Work Is Never Done--Farther Down the Track. / https://dc.etsu.edu/etsu_books/1101/thumbnail.jpg

The Johnson City Sessions were held in Johnson City, Tennessee in October 1928 and October 1929. This work "...marks the first time these recordings have been assembled in any format. Collectively, these 100 songs and tunes are regarded by scholars and record collectors as a strong and distinctive cross-section of old-time Appalachian music just before the Great Depression. The four CDs gather every surviving recording from the sessions, while the accompanying 136-page LP-sized hardcover book contains newly researched essays on the background to the sessions and on the individual artists, with many rare and hitherto unpublished photographs, as well as complete song lyrics and a detailed discography." -- Back cover. Ted Olson (East Tennessee State University) and Tony Russell are the re-issue producers. / https://dc.etsu.edu/etsu_books/1112/thumbnail.jpg