Dissertationen zum Thema „Nika2“

Measurement of the gas velocity distribution in galaxy clusters provides insight into the physics of mergers, through which large scale structures form in the Universe. Velocity estimates within the intracluster medium (ICM) can be obtained via the Sunyaev-Zel'dovich (SZ) effect, but its observation is challenging both in term of sensitivity requirement and control of systematic effects, including the removal of contaminants. In this paper we report resolved observations, at 150 and 260 GHz, of the SZ effect toward the triple merger MACS J0717.5 + 3745 (z = 0.55), using data obtained with the NIKA camera at the IRAM 30 m telescope. Assuming that the SZ signal is the sum of a thermal (tSZ) and a kinetic (kSZ) component and by combining the two NIKA bands, we extract for the first time a resolved map of the kSZ signal in a cluster. The kSZ signal is dominated by a dipolar structure that peaks at -5.1 and + 3.4 sigma, corresponding to two subclusters moving respectively away and toward us and coincident with the cold dense X-ray core and a hot region undergoing a major merging event. We model the gas electron density and line-of-sight velocity of MACS J0717.5 + 3745 as four subclusters. Combining NIKA data with X-ray observations from XMM-Newton and Chandra, we fit this model to constrain the gas line-of-sight velocity of each component, and we also derive, for the first time, a velocity map from kSZ data (i. e. that is model-dependent). Our results are consistent with previous constraints on the merger velocities, and thanks to the high angular resolution of our data, we are able to resolve the structure of the gas velocity. Finally, we investigate possible contamination and systematic effects with a special care given to radio and submillimeter galaxies. Among the sources that we detect with NIKA, we find one which is likely to be a high redshift lensed submillimeter galaxy.

Le nickel est un cofacteur essentiel à l'activité de certaines protéines bactériennes, mais il est également toxique à forte concentration. De ce fait, il est indispensable aux bactéries de posséder un système d'import du Ni2+ spécifique et hautement régulé. Dans le cas d'Escherichia coli, il s'agit d'un système ABC composé des cinq protéines de l'opéron nikabcde : NikA, une protéine périplasmique, NikB et NikC, deux protéines formant un pore à travers la membrane interne, et les protéines NikD et NikE, deux protéines cytoplasmiques hydrolysant l'ATP. La régulation de l'expression de cet opéron est assurée par FNR, l'activateur, et de NikR, le répresseur. Dans un premier temps, nous avons travaillé sur une structure de la protéine NikA, résolue à partir de cristaux appartenant au système orthorhombique. Elle nous a permis de montrer que NikA ne fixait pas le nickel sous une forme pentahydratée comme cela était décrit dans la littérature, mais sous la forme d'un complexe FeEDTA(H2O)-, ce qui suggère que le nickel ne se fixe pas directement à la protéine, mais par l'intermédiaire d'un métallophore de structure proche de celle de l'EDTA. En remplaçant l'étape d'extraction périplasmique à l'EDTA par une étape utilisant le chloroforme, nous avons résolu, une seconde structure de NikA à partir de cristaux appartenant au système cristallin hexagonal. Dans ce cas, on observe, dans le site de fixation de la protéine, un nickel en complexe avec une molécule similaire à l'EDTA, laquelle a de fortes chances d'être le métallophore physiologique, que nous avons tenté de caractériser. Nous abordons aussi des études cristallographiques préliminaires concernant NikR<br>Nickel is an essential cofactor for several proteins found in bacteria, but it is also toxic at high concentrations. Consequently, microorganisms need a highly regulated and specific import system of Ni2+. In Escherichia coli, this system is composed of five proteins encoded by the nikabcde operon (which is an ATP Binding Casette): NikA, a periplamic protein, NikB and NikC, two transmembrane proteins which create a pore in the inner membrane, and the cytoplasmic proteins NikD and NikE, which hydrolyse ATP and provide the energy for the transport process. FNR (Fumarate Nitrate Regulator) is the activator, and NikR the repressor of the transcription of the nik operon. We solved the NikA protein structure by molecular replacement and found that contrary to what was reported in a previous crystallographic analysis, the protein doesn't bind a pentahydrate nickel, but an FeEDTA(H2O)- complex. The EDTA, that is not a natural molecule, was introduced during the periplasmic extraction. These results suggest that NikA does not fix nickel directly, but it does it through a natural metallophore. Indeed, when we changed the periplasmic extraction with EDTA to a protocol using chloroform, we obtained a new structure where the nickel in complexed to a molecule similar to EDTA. Since this seems to be the physiological metallophore we have tried to characterise it using a variety of techniques. We also report a preliminary crystallographic analysis of NikR

L'utilisation de l'ADNc Nia2, codant pour une nitrate réductase (NR) de Nicotiana tabacum, sous contrôle d'un promoteur constitutif (p35S), dans des plantes de tabac transgéniques, a permis l'obtention de teneurs en nitrate remarquablement faibles pour certains génotypes transgéniques. Cette stratégie pourrait s'avérer une voie intéressante à utiliser chez des espèces accumulatrices de nitrate comme la laitue et l'épinard. Nous avons donc créé et étudié une population de laitues transformées avec la construction p35S ::Nia2. Cependant, l'analyse des teneurs en nitrate n'a jamais permis d'observer de baisses de ces transformants par rapport aux plantes témoins. Afin d'expliquer ces résultats, nous avons cherché a mieux comprendre le fonctionnement du transgène p35S ::Nia2 chez la laitue. Un test in vitro, conçu pour mettre en évidence une activité NR liée à l'expression du transgène, a permis de vérifier que la protéine transgénique était active dans quatre génotypes transformés. Cependant cette expression n'a aucune répercussion sur l'absorption du nitrate et les activités NR totales (endogène + transgénique) contrairement a ce qui avait été observé chez le tabac. Nous nous sommes alors intéressés de plus près à l'expression du transgène et des gènes Nia endogènes dans ces plantes par hybridations northern. Les ARNm Nia2 n'ont été détectés que dans les cotylédons de plantules cultivées sur un milieu assurant une diminution importante de la transcription des gènes Nia endogènes. L'ensemble des résultats obtenus sont compatibles avec l'implication d'un mécanisme de suppression post-transcriptionnelle particulier agissant sur la dégradation soit des ARNm Nia2 et Nia endogènes soit des ARNm Nia2 seuls. La dégradation spécifique des ARNm transgéniques serait initiée de façon très précoce au cours du développement des plantules et d'autant plus tôt que l'expression des gènes Nia endogènes est importante<br>The nitrate reductase (NR) Nia2 cDNA from tobacco had been introduced into tobacco plants under the control of the 35S promoter (p35S). Some of these transgenic plants showed low nitrate levels in their leaves. It was interesting to apply this strategy to plants like lettuce or spinach that accumulate high nitrate levels. In this way, we produced and studied a population of transgenic lettuce transformed with the p35S::Nia2 construction. None of these lettuce showed low nitrate levels when compared to the untransformed plants. In order to explain these results, we tried to find and analyze lettuce having a transgenic NR activity. An hi vitro test was used to detect plants specifically expressing the NR activity from Nia2. Four genotypes showed this activity. Nevertheless, no repercussion on nitrate absorption and total NR activity (endogenous + transgenic) was detected in these plants as had been shown previously for transgenic tobacco. Then, we focused on the transgene and endogenous Nia gene expression. By northern blot, we showed that the Nia2 mRNA were only detected in cotyledons of plantlets which were growing on a medium for which the transcription of the endogenous Nia gene was very low. Our results are in accordance with the involving of a specific PTGS (Post-Transcriptional Gene Silencing) mechanism in these transgenic lettuce inducing the degradation either of the Nia2 and endogenous Nia mRNA (phenomenon already observed in tobacco) or of the Nia2 mRNA only. The specific Nia2 mRNA degradation seems to be initiated early in plantlet development and even sooner when the transcription of the endogenous Nia is great. Experiments are currently being conducted in order to develop tools which will be important to confirm and well characterize this mechanism in p33S::Nia2 lettuce

Through using a Positive Youth Development framework and culturally based education program, Konaway Nikka Tillicum Native American Youth Academy aspires to mentor and prepare Native youth through high school and on to higher education. This collaborative research partnership investigated cultural identity, self-esteem, and academic optimism of Native American youth attending the academy. The results of this program evaluation found that cultural identity, self-esteem, and academic optimism were all closely related to each other as well as that they increased significantly when measured before and after the academy. GPA was found to not be predictive of cultural identity, self-esteem, or academic optimism prior to students attending the academy. Lastly, the relationship between cultural identity and academic optimism appeared to be explained through the indirect effect of self-esteem. The results suggest that culturally based education and positive youth development programs such as Konaway are efficacious in increasing protective factors among Native American youth.

Questa tesi si propone di indagare il carattere, l’origine e la legittimità giuridica del nikāḥ al-mut‘a, ‘‘matrimonio temporaneo’’ o meglio ‘‘di godimento’’, attraverso la traduzione di un documento originale: il Wasā‘il al-Shī‘a di al-Ḥurr al-‘Ᾱmilī. Dell’intera opera, ovvero una vasta raccolta di ḥadiṯ che toccano le principali questioni del diritto islamico, abbiamo preso in esame esclusivamente la voce riguardante il matrimonio temporaneo, che si trova all’interno del quattordicesimo volume della raccolta, dedicato interamente alla questione del matrimonio. La traduzione, dalla lingua araba a quella italiana, costituisce il corpus principale della tesi e vuole essere il punto nodale dal quale le conclusioni verranno tratte. Abbiamo tentato inoltre di sottolineare la diversità dell’approccio sunnita e sciita rispetto a tale questione e di tracciare un breve excursus delle loro discordanze ideologiche. Il nikāḥ al-mut‘a, rappresentando un istituto matrimoniale in piena regola, è provvisto di molti aspetti che lo accomunano ad un normale matrimonio e che abbiamo preso in esame: la stipulazione di un contratto bilaterale tra le parti, la presenza di un walī e l’elargizione di una dote. Allo stesso tempo abbiamo analizzato peculiarità specifiche della mut‘a, legate proprio alla sua natura temporanea: la scadenza stabilita del contratto; l’assenza, anche se non in tutti i casi, di un’eredità; l’articolazione di formule e locuzioni che legalizzano l’unione delle due parti e la rendono lecita; i dettami che regolano il riconoscimento della prole nata sotto il contratto, i periodi di continenza(‘idda) della donna allo scadere del termine di ogni unione. Infine abbiamo cercato di trattare ogni aspetto sopra citato attraverso un ottica sia storica che giuridica, al fine di fornire un quadro utile alla comprensione della mut‘a a un lettore contemporaneo.

Although a casual reading of the Supreme Court of Canada's decisions in R. v. Nikal and R. v. Lewis might suggest otherwise, this thesis will argue that Court's decisions in two recent British Columbia aboriginal fishing cases do not apply in Ontario. In doing so, it will be shown that the Supreme Court of Canada relied on evidence of historic Crown policies towards aboriginal fishing rights in Upper Canada in the absence of appropriate context as to how those policies evolved. As a result, the Court wrongly concluded that fisheries could not be the subject of exclusive aboriginal rights. As a result of its reliance on historically discriminatory policies of the Crown, it will be shown that the Court favoured the fishing privileges of non-aboriginal Canadians over the pre-existing rights and title of aboriginal peoples. In exploring these issues, this thesis will include a review of case-law, legislation and historical materials from the 17$\sp{\rm th}$, 18$\sp{\rm th}$ and 19$\sp{\rm th}$ centuries as well as contemporary case-law and legislation.

La mesure de la distribution de matière dans l'Univers offre une sonde importante pour la cosmologie. Elle peut être tracée à différentes étapes de la formation des structures en utilisant l'analyse des anisotropies primaires et secondaires du fond diffus cosmologique (CMB). Cette thèse se focalise sur l'analyse des données du satellite Planck et celles de la caméra NIKA installée au sol au télescope de 30 mètres de l'IRAM.La première partie introduit le contexte, en se concentrant sur: 1) l'inflation, qui procure une origine naturelle aux fluctuations de matière observées dans l'Univers; 2) la réionisation, qui correspond au moment où les premières étoiles se forment; 3) les amas de galaxies, qui sont les briques de l'Univers plus récent.La seconde partie se concentre sur la réduction des données de NIKA. Le développement de la chaîne d'analyse, qui permet de passer des données brutes aux cartes astrophysiques, est présenté. Elle est dédiée aux détecteurs à inductance cinétique, nouvellement développés pour la caméra NIKA. Les outils et les simulations utilisés pour caractériser les cartes sont aussi présentés.La troisième partie est dédiée à l'observation et l'analyse des amas de galaxies par effet Sunyaev-Zel'dovich (SZ), i.e. l'interaction Compton inverse entre les photons du CMB et les électrons énergétiques dans les amas. Une fois obtenues, les cartes SZ sont combinées avec des données X afin de mesurer les propriétés thermodynamiques et de matière des amas observés. Les résultats principaux sont: la première observation de l'effet SZ avec des détecteurs à inductance cinétique, la mesure du profil de pression dans un amas à haut redshift (z=0.89), l'étude de la contamination par les sources ponctuelles dans un amas résolu, et la cartographie SZ dans un amas en collision triple.La dernière partie présente l'analyse des données de Planck en polarisation. Les effets systématiques aux grandes échelles angulaires et les outils développés pour les identifier et les corriger y sont discutés. Les données en polarisation aux grandes échelles permettent à la fois de chercher les empreintes des fluctuations quantiques générées pendant l'inflation et de mesurer la réionisation<br>The measurement of the matter distribution in the Universe provides valuable tests for cosmology. It can be traced at various steps of the formation of structures using the analysis of the primary and secondary anisotropies in the Cosmic Microwave Background (CMB). This thesis focuses on the data analysis of the observations of the Planck satellite and that of the ground-based camera NIKA installed at the IRAM-30m telescope.The first part introduces the context, focussing on: 1) the inflation, which provides a natural origin for the matter fluctuations seen in the Universe; 2) the reionization, which corresponds to the moment when the first stars form; 3) clusters of galaxy, that are the building blocks of the more recent Universe.The second part focuses on the data reduction of the NIKA data. The development of the data reduction pipeline, allowing to go from raw data to maps, is presented. It is dedicated for the newly developed kinetic inductance detectors used by NIKA. Tools and simulations are also constructed to characterize the maps.The third part is dedicated to the observation and the analysis of galaxy clusters through the Sunyaev-Zel'dovich (SZ) effect, i.e. the inverse Compton interaction of CMB photons and free electrons in clusters. Once recovered, the SZ maps are combined to X-ray data to measure the matter content and thermodynamic properties of the observed clusters. The main results are: the first observation of the SZ effect with kinetic inductance detectors, the measurement of the pressure profile of a high redshift cluster ($z=0.89$), the study of point source contamination in a resolved cluster, and the SZ mapping in a triple merger.The last part is dedicated to the analysis of Planck polarization data. In particular, we discuss large angular scale systematics and the tools developed to identify and correct for them. The large scales CMB polarization data allows both to search for the imprint of the quantum fluctuations generated during inflation, and to measure the reionization

Chez les procaryotes, les systèmes ABC (ATP-binding cassette) canoniques permettent un import efficace et de haute affinité du nickel, en grande partie via l'action de la Ni-BP (nickel-binding protein) qui va jouer le rôle de récepteur extracytoplasmique du nickel avant son passage à travers la membrane interne. Dans ces travaux, nous avons cherché à mieux caractériser les stratégies d'import de nickel par les bactéries, notamment par l'étude cristallographique des Ni-BP. La résolution des structures de cinq de ces protéines, en interaction avec du nickel, nous a permis d'identifier les sites de fixation et ainsi de mettre en évidence les différents modes d'interaction de ce métal avec les Ni-BP. Nos résultats montrent notamment que la coordination du nickel requiert toujours la présence d'un métallophore exogène, appelé nickelophore. En parallèle, des études in vivo ont été conduites sur Escherichia coli, montrant que cette bactérie semble être capable de synthétiser son propre nickelophore. D'autre part, ces travaux ont permis la résolution de la structure de HypB de Helicobacter pylori en interaction avec du nickel. Celle-ci permet de mieux appréhender le rôle central de cette protéine au sein des voies de maturation des enzymes à nickel<br>In prokaryotes, canonical ABC (ATP-binding cassette) importers allow an efficient uptake of nickel with high affinity through the inner membrane, largely via the action of the extracytoplasmic nickel-binding protein (Ni-BP). In this work, we intended to better understand the strategies developed by bacteria to scavenge nickel in the environment, especially through the structural studies of several Ni-BP. The resolution of the crystal structures of five Ni-BPs from diverse bacteria, in interaction with nickel, led us to identify their nickel-binding sites and shed light on the different binding modes. Our results show that the presence of an exogenous metallophore, called nickelophore, is always required. In vivo studies in Escherichia coli were also conducted, showing that this bacteria seems to be able to synthesize its own nickelophore. In addition, we have solved the crystal structure of Helicobacter pylori HypB in complex with nickel. This result provides insight into its cellular function in nickel enzyme maturation pathways

Opisane&nbsp; su&nbsp; sinteze&nbsp; novih&nbsp; liganada&nbsp; bis(ftalazin-1hidrazon)-2,6-diacetilpiridna&nbsp; (Hz₂DAP&middot;2HCl),&nbsp; bis(3-hlorpiridazin-6-hidrazon)-2,6-diacetilpiridina (Hp₂DAP),&nbsp; 3-hlorpiridazin-6-hidrazon&nbsp; di(2-piridil) ketona&nbsp; (HpDPK),&nbsp; ftalazin-1-hidrazon&nbsp; di(2-piridil)ketona&nbsp; (HzDPK)&nbsp; i&nbsp; ftalazin-1-hidrazon&nbsp; piridin-2-karbaldehida&nbsp; (HzPY).&nbsp; Zajedničko&nbsp; svojstvo&nbsp; dobijenih liganada&nbsp; je&nbsp; &scaron;to&nbsp; sadrže&nbsp; piridinski&nbsp; i&nbsp; diazinski&nbsp; prsten&nbsp; i sadrže&nbsp; samo&nbsp; donorne&nbsp; atome&nbsp; azota.&nbsp; Tokom&nbsp; nastajanja kompleksa dolazi do deprotonacije liganada. Svi ligandi su&nbsp; okarakterisani&nbsp; elementalnom&nbsp; analizom, termoanalitičkim&nbsp; metodama&nbsp; i&nbsp; metodom&nbsp; IR spektroskopije,&nbsp; dok&nbsp; neki&nbsp; i&nbsp; metodom&nbsp; NMR spektroskopije&nbsp; kao&nbsp; i&nbsp; rendgenskom&nbsp; strukturnom analizom.Za&nbsp; sintezu&nbsp; koordinacionih&nbsp; jedinjenja&nbsp; primenjeni&nbsp; soli Co(II),&nbsp; Ni(II),&nbsp; Cu(II)&nbsp; i&nbsp; Zn(II).&nbsp; Dobijeni&nbsp; kompleksi su okarakterisani&nbsp; elementalnom&nbsp; analizom, konduktomerijskim&nbsp; i&nbsp; magnetnim&nbsp; merenjima,&nbsp; IR spektroskopijom i termoanalitičkim metodama. Barem jedan&nbsp; kompleks&nbsp; iz&nbsp; svake&nbsp; serije&nbsp; je&nbsp; okarakterisan&nbsp; i rendgenskom strukturnom analizom. Urađena&nbsp; su&nbsp; i&nbsp; ispitivanja&nbsp; antimikrobne&nbsp; aktivnosti odabranih&nbsp; jedinjenja&nbsp; prema&nbsp; predstavnicima&nbsp; grampozitivnih i gram-negativnih bakterija i kulturu kvasca. Pored&nbsp; toga,&nbsp; urađena&nbsp; su&nbsp; i&nbsp; ispitivanja&nbsp; citotoksične,antiproliferativne&nbsp; i&nbsp; inhibitorne&nbsp; aktivnosti&nbsp; jedinjenja prema&nbsp; roditeljskim&nbsp; i&nbsp; multirezistentnim&nbsp; T-limfomnim ćelijama&nbsp; kancera.&nbsp; Utvrđeno&nbsp; je&nbsp; da&nbsp; neka&nbsp; jedinjenja pokazuju&nbsp; izrazito&nbsp; mikrobicidno,&nbsp; citotoksično, antiproliferativno i inhibitorno dejstvo.<br>The synthesis of new ligands dihydrochloride salt of 2,6-diacetylpyridne&nbsp;&nbsp; bis(phthalazine-1hydrazone) (Hz₂DAP&bull;2HCl),&nbsp; 2,6-diacetylpiridine&nbsp; bis(3- chloropyridazine-6-hydrazone)&nbsp; (Hp₂DAP),&nbsp; di(2-pyridyl)ketone&nbsp; 3-chloropyridazine- 6-hydrazone (HpDPK),&nbsp; di(2-pyridyl)ketone&nbsp; phthalazine-1-hydrazone&nbsp; (HzDPK)&nbsp; and&nbsp; &nbsp; pyridine-2-carbaldehide phthalazine-1-hydrazone&nbsp; (HzPY)&nbsp; have&nbsp; been described. All the ligands contain pyridine and diazine core and all of them have only nitrogen donor atoms. During the complex formation the deprotonation of ligands takes&nbsp; places.&nbsp; All&nbsp; of&nbsp; the&nbsp; ligands&nbsp; have&nbsp; been characterized&nbsp; by&nbsp; elemental&nbsp; analysis,thermoanalytical&nbsp; methods&nbsp; and&nbsp; IR&nbsp; spectroscopy.&nbsp; In some&nbsp; cases&nbsp; also&nbsp; by&nbsp; NMR&nbsp; spectroscopy&nbsp; and&nbsp; X-ray structural analysis.Co(II), Ni(II), Cu(II) and Zn(II) salts were&nbsp; used for the synthesis&nbsp; of&nbsp; the&nbsp; coordinational&nbsp; compounds.&nbsp; The obtained complexes were characterized by elemental analysis,&nbsp; molar&nbsp; conductivity&nbsp; and&nbsp; magnetic measurements,&nbsp; IR&nbsp; spectroscopy&nbsp; and thermoanalytical&nbsp; methods.&nbsp; At&nbsp; least&nbsp; one complex&nbsp; of each&nbsp; series&nbsp; were&nbsp; characterized&nbsp; by&nbsp; X-ray&nbsp; structural analysis.The antimicrobial activity of some of the compounds toward&nbsp; Gram-positive/Gram- negative&nbsp; bacteria furthermore,&nbsp; the&nbsp; cytotoxic,&nbsp; antiproliferative&nbsp; and inhibitory&nbsp; activity&nbsp; toward&nbsp; sensitive&nbsp; parental&nbsp; andmultiresistant&nbsp; T-lymphoma&nbsp; cancer&nbsp; cells&nbsp; have&nbsp; also been carried out. It&nbsp; can&nbsp; be&nbsp; concluded&nbsp; that&nbsp; some&nbsp; of&nbsp; the&nbsp; compounds exhibit&nbsp; outstanding&nbsp; antimicrobial,&nbsp; cytotoxic, antiproliferative, and inhibitory activity.

In this thesis, I aimed to identify factors shaping plant distribution at different spatial scales, correlate them with environmental heterogeneity, identify causal processes and test general hypothesis on the nature of response curve shapes and species richness patterns. General review of the topic is introduced in the first chapter, followed by five chapters presenting three already published studies and two manuscripts. The first study deals with processes responsible for creation of fine-scaled spatial pattern of spruce seedlings and saplings, emerging after bark-beetle disturbance in mountain spruce forest. Aggregated pattern, replicating previous generation of spruce trees, emerges in consequence to microsite-dependent mortality, as was surveyed through repeated monitoring of the fate of individual seedlings. The second study explores spatial variability in forest understory temperatures at the landscape scale and its relevance for understory plant distribution. As the main source of variability in understory communities we identified seasonal maximum temperatures. Using GIS modelling approach, we created spatially continuous prediction, which outperformed state-of-art climatic grids used currently by ecologists. The third study on the shape of species responses along elevational gradients...

Le nickel est un cofacteur essentiel à l'activité de certaines protéines bactériennes, mais il est également toxique à forte concentration. De ce fait, il est indispensable aux bactéries de posséder un système d'import du Ni2+ spécifique et hautement régulé. Dans le cas d'Escherichia coli, il s'agit d'un système ABC composé des cinq protéines de l'opéron nikabcde : NikA, une protéine périplasmique, NikB et NikC, deux protéines formant un pore à travers la membrane interne, et les protéines NikD et NikE, deux protéines cytoplasmiques hydrolysant l'ATP. La régulation de l'expression de cet opéron est assurée par FNR, l'activateur, et de NikR, le répresseur. Dans un premier temps, nous avons travaillé sur une structure de la protéine NikA, résolue à partir de cristaux appartenant au système orthorhombique. Elle nous a permis de montrer que NikA ne fixait pas le nickel sous une forme pentahydratée comme cela était décrit dans la littérature, mais sous la forme d'un complexe FeEDTA(H2O)-, ce qui suggère que le nickel ne se fixe pas directement à la protéine, mais par l'intermédiaire d'un métallophore de structure proche de celle de l'EDTA. En remplaçant l'étape d'extraction périplasmique à l'EDTA par une étape utilisant le chloroforme, nous avons résolu, une seconde structure de NikA à partir de cristaux appartenant au système cristallin hexagonal. Dans ce cas, on observe, dans le site de fixation de la protéine, un nickel en complexe avec une molécule similaire à l'EDTA, laquelle a de fortes chances d'être le métallophore physiologique, que nous avons tenté de caractériser. Nous abordons aussi des études cristallographiques préliminaires concernant NikR.

碩士<br>臺東師範學院<br>教育研究所<br>91<br>ABSTRACT This is a study of a life history. By portraying the life history of the research subject and further analyzing the stories in the body of the thesis, this study aims to identify and analyze the significant events in a life history as well as the influence or underlying implications of certain issues over the research subject. The research subject is the researcher herself. By adopting the method of biographical narration, the researcher first presents the important events in the life history of herself, from childhood to the present, as the main body of the study. Literature analysis is further employed on the discussion of the relations of the factors, such as her original family background, gender as female, her identify and recognition of an aborigine, and the clashes between social relations and her culture, to the research subject in her childhood, attending schools, profession, marriage, and family. In the process of recalling, writing, examining, proving, and criticizing, the researcher is given an opportunity to once again face the bright, dark, or gray aspects of her life, and furthermore, challenge and transcend herself in the narration of the stories that has the effect similar to self release and self treatment, in an attempt to identify her position in her career and life─as an aboriginal teacher, to help students foster a view of multi-culturalism, the respect for different ethnic cultures and the recognition of their owns.

Nickel, essential to many biological processes, is a component of the active sites of enzymes that catalyze both redox and non-redox reactions. Here the results of investigations aimed at understanding the structure and function of four nickel metalloproteins is presented. X-ray absorption spectroscopy (XAS) was used to explore the nickel sites in Escherichia coli NikA and NikR. NikA is a Ni-binding component of the NikA-E nickel specific permease, responsible for the uptake of Ni in E. coli. NikA also plays a role in the negative chemotaxis associated with toxic Ni concentrations. NikA plays a non-redox role, and XAS of its nickel site exhibited an octahedral environment composed of six N/O-ligands. NikR regulates Ni uptake and translocation by regulation of the nik operon. XAS of the high affinity nickel sites of NikR holoprotein, C-terminal domain, and a half-site DNA complex revealed a planar four coordinate, a five coordinate, and an octahedral site respectively. There is a predominance of N/O-ligation for the NikR samples as expected for Ni proteins with a non-redox role. Only the holoprotein possesses one sulfur ligand. The Ni coordination environments support a proposed role for NikR function where the N-terminus binds DNA specific subsites, and the C-terminal senses, and binds nickel and stabilizes the NikR-DNA complex. XAS was used to probe the structure of the novel nickel containing acireductone dioxygenase (NiARD). Klebsiella pneumoniae produces two ARD's, involved in its methionine salvage pathway. They differ only in their metal content, but catalyze different reactions. NiARD provides a shunt to the methionine salvage pathway. XAS of resting NiARD and the enzyme substrate complex shows an octahedral resting NiARD with N/O-ligands, where 3 or 4 are histidines. Substrate binds to NiARD in a bidentate fashion displacing two ligands, at least one being a histidine. Nickel also plays a key redox role in NiFe hydrogenases. Here circular dichroism and electronic spectroscopy were used to monitor conformational changes in Thiocapsa roseopersicina NiFe hydrogenase as a function of redox poise. Although changes may occur at the metal sites, the resulting changes in the protein secondary structure are small.

Η διπλωματική εργασία διερευνά τη σημασία του θεσμού της Εταιρικής Κοινωνικής Ευθύνης και της Χρηματοοικονομικής Απόδοσης μέσα στη σύγχρονη επιχειρηματική δραστηριότητα. Για το σκοπό αυτό, αρχικά παρουσιάζονται οι δυο αυτές έννοιες και στην συνέχεια γίνεται αναφορά στο πώς διάφορες έρευνες καταλήγουν στην σχέση τους. Η εργασία χωρίζεται σε δυο μέρη. Το ποιοτικό που περιλαμβάνει το μεγαλύτερο μέρος της εργασίας και στηρίζεται κυρίως σε ένα μεγάλο εύρος παγκόσμιων και ευρωπαϊκών βιβλιογραφικών πηγών που αφορούν την Εταιρική Κοινωνική Ευθύνη και την Χρηματοοικονομική απόδοση και το ποσοτικό που χρησιμοποιείται κυρίως για την χρήση των αριθμοδεικτών στο 5 κεφάλαιο.<br>This thesis explores the importance of the institution of Corporate Social Responsibility and Financial Performance in contemporary business. For this purpose, initially presented these two concepts, and then referring to how various investigations resulting in the relationship. The task is divided into two parts. The quality that includes the majority of the task and is mainly based on a wide range of global and European literature sources relating to Corporate Social Responsibility and Financial Performance and quantitative used mainly for using the indicators in Chapter 5.

Assessment of the impact of landscape structure on the dispersion of lynx in Posumavi Abstract: The big predators are a traditional group of bioindicative species, whose presence shows the state of environment and landscape within a region. As these animals recolonize the cultural landscape of central Europe it's needed to understand their space requirements and habitat preferences. The lynx (Lynx lynx) has been one of the Sumava forest species since the 70's. After almost 40 years the population of lynx has spread from Sumava and Bavarian Forest to forested parts of Cesky Les, Smrcina and Novohradske hory and to both sides of state borders. However today's state of lynx population, stable number of animals or genetic variability is endangered by many factors. Long term viability of the lynx population is - besides poaching or illegal hunting − affected by the loss of suitable habitats and ongoing fragmentation of the landscape. One of the possible solutions of negative impacts is delineation and protection of landscape permeability of habitat corridors. They might have provide supply of new individuals to small, extinction prone population and at the same time they could reinforce overall fitness population. This thesis has three main objectives:1) evaluation of landscape fragmentation and connectivity in...

The aim of this thesis was to identify factors that contribute to invasiveness of species in the genus Impatiens. This genus is horticulturally attractive and includes several species that are known to have naturalized outside their native ranges, while others did not escape, in spite of being frequently cultivated. When looking for traits associated with invasiveness, it is useful to focus on congeneric species. Their traits and dispersal modes are less influenced by phylogeny, than when comparing unrelated species or even complete floras. This helps to account for traits that favour invasive species over native ones and thus identify potential invaders more precisely. A superior invader performance is attributed to a competitive advantage over native species that can lead in extreme case to competitive exclusion of the latter. Invasive and native species com- pete only if their niches overlap and the strength of competition depends on niche similarity. Importantly, invasive species are considered to be able to maintain their high competitiveness over a wide range of environmental conditions, while native ones often have narrower environ- mental optima. Lastly, competitive outcome can vary over life stages and depends on the degree of species dominance, which is rarely taken into account. Spread and...

The requirements of true frogs on breeding sites were monitored at 19 locations in the Hradec Králové Region and the Central Bohemia Region and Vysočina Region. Specific sites were selected according to the high variability. Breeding sites are mutually different representation of true frogs, water volume, depth, water and surrounding vegetation. The data of oviposition three different species of czech frogs - moor frog (Rana arvalis), agile frog (Rana dalmatina) and common frog (Rana temporaria) - were collected in the spring months, from the end of March until the end of April, from 2012 to 2015. During this period were collected data from 927 egg clutches of these species. The data were obtained by non-invasive way - measuring of inividual clutches directly on the reproductive site. At each breeding site was also recorded the required parameters of the breeding pond and the surrounding environment (presence of true frogs, the water volume and depth of the pond, the presence and density of aquatic vegetation, surrounding vegetation, air and water temperature, pH value of water, etc.). The results presented in this work confirm that the three species of true frogs have, in some parameters, different standards to select of breeding sites. This clarification of species- specific claims is also...

This work gives an overview of the composition of the diet of bats in the eastern Mediterranean and the Middle East, discusses the structure of bat communities in different bioregions of the area in terms of hunting strategies and resource partitioning and last but not least, how echolocation and morphological characteristics of bats affect the composition of the diet. Although some samples were relatively small therefore it is necessary to look soberly at their informative value, and thus their importance is undeniable. The study in some cases provides completely the first information regarding the composition of diet in several species. Asellia arabica mainly catches Coleoptera (Scarabaeidae), Triaenops persicus hunts Lepidoptera, but Heteroptera, Coleoptera (Scarabaeidae) and Orthoptera too, while Triaenops parvus is a specialist in hunting Lepidoptera. Rhinopoma muscatellum hunts mainly Formicoidea, followed by Coleoptera (Melolonthinae) and Heteroptera, Rhinopoma hadramauticum hunts Formicoidea. Lepidoptera of different size, Heteroptera and Coleoptera are the prey of Chaerephon nigeriae. Pipistrellus hanaki has a wide niche breadth as other species of the genus Pipistrellus. In this study Brachycera, Auchenorrhyncha and Coleoptera primarily occurred in its diet. Not yet described species of...

Non-Interactive Key Agreement (NIKA) is a cryptographic primitive which allows two parties to agree on a shared secret key without any interaction. Identity-based Non-Interactive Key Agreement (ID-NIKA) allows each party to compute shared secret key using its own secret key and the peer’s identity. ID-NIKA can be used to establish shared secret keys in ad-hoc networks using minimal battery power and communication. Mobile Ad-hoc NETwork (MANET) is a network of mobile and moderately resource constrained devices communicating through a wireless medium. Examples of standard MANET devices are laptops, cellphones etc. Due to the inherent characteristics like mobility, dynamic topology and lack of centralized infrastructure, MANETs face some serious security issues. We are particularly interested about ID-NIKA in MANETs. This is of crucial interest for secure communication between two nodes in MANETs. In 2008, Gennaro et al. introduced a scheme called Hybrid Hierarchical Key Agreement Scheme (HH-KAS). HH-KAS uses subset based key agreement scheme at the non-leaf levels and a key agreement scheme due to Sakai et al. (referred as SOK-KAS) at the leaf level. HH-KAS is (i) non-interactive, (ii) identity-based, (iii) hierarchical and (iv) fully resilient against node compromises at leaf level and resilient against node compromises upto certain threshold values in non-leaf levels. Thus one can say that HH-KAS is partially resilient against node compromises. In their paper the authors claim that there is no key agreement scheme for MANETs in the literature, with all above four properties. This was motivated as an interesting open problem in this area. Guo et al. proposed a scheme known as Strong Key Agreement Scheme (SKAS) in 2011. The authors claimed it as a potential solution to the open problem posed by Gennaro et al. in their work. However, in 2014, Zhu et al. showed a concrete attack on SKAS. This attack makes SKAS practically useless for real life applications. Our main contribution is a hybrid scheme using two already existing schemes. Our scheme uses a deterministic key pre-distribution scheme by Lee and Stinson termed as Basic Id One-way function Scheme (BIOS) at level 1 (where root is at level 0). Beyond level 1, we use SOK-KAS for key agreement. We refer our scheme as BIOS-SOK key agreement. BIOS and SOK schemes satisfy properties (i), (ii) and (iv) but none of them is hierarchical in nature. In our work we have made an amalgam of both schemes which is hierarchical in nature. Thus, BIOS-SOK scheme satisfies (i), (ii), (iii) and is also fully resilient against arbitrary number of node compromises at any level. BIOS-SOK scheme also possesses the benefits of low space requirement, low shared key computation time and better scalability for many real-life applications when compared with the scheme of Gennaro et al. In HH-KAS, the key agreement is carried out only at the leaf level. In BIOS-SOK scheme, any two nodes in the hierarchy (at same or different levels) can compute shared secret key. We also provide a rigorous security analysis for our scheme in a stronger security model compared to the security model used for HH-KAS.<br>Indian Institute of Science

Light is essential component of forest ecosystem, as limited light availability in forest-floor restricts herb and tree seedlings growth. Importance of light availability for maintaining plant species diversity and community structure wasn't sufficiently evaluated in the Czech Republic. This study focus on the ecological relevance of light availability on both landscape and local scale. Relationship of light to cover, diversity and species composition was quantified in the thesis. Dominant tree species affected light availability and its spatial variability. Light availability was along the soil reaction and slope most influential factor for large-scale species diversity. Within-site light variability affected plant diversity more than soil reaction variability. Measuring light by means of hemispherical photography seems to be an appropriate for studies like this. Light availability influnence on community compostition is weak in comparison with other environmental gradients.

Species distribution and composition of bird communities of South Africa is not accidental, but is influenced by environmental conditions, habitat structure, and natural history of the area. Functional traits of the species (morphology, dietary strategies or reproductive parameters) give information on how the individuals interact with the environment they live in. The description of the functional characteristics, expose specific adaptations and the role of the species in the studied ecosystem. On the basis of functional characteristics we are able to estimate functional diversity of studied community. The spatial variability of species and functional diversity allocates longitudinal gradient. Regarding the morphological and reproductive parameters that are continuous in nature and more species- specific, we observe a faster increase in functional diversity. Considering the feeding preferences that are categorical and show a limited number of levels, a modest increase in functional diversity apparent is. Dietary functional diversity is more evenly distributed. Relationship between the functional and species diversity can provide us with information about how species are added to the community or answer the question to what extent the higher number of species requires more ecological space. The...

A l’heure actuelle, les biocarburants renouvelables et qui ne nuit pas à l'environnement sont à l'étude intensive en raison de l'augmentation des problèmes de santé et de la diminution des combustibles fossiles. H2 est l'un des candidats les plus prometteurs en raison de ses caractéristiques uniques, telles que la densité d'énergie élevée et la génération faible ou inexistante de polluants. Une façon attrayante pour produire la H2 est par les bactéries photosynthétiques qui peuvent capter l'énergie lumineuse pour actionner la production H2 avec leur système de nitrogénase. L'objectif principal de cette étude était d'améliorer le rendement de H2 des bactéries photosynthétiques pourpres non sulfureuses utilisant une combinaison de génie métabolique et le plan des expériences. Une hypothèse est que le rendement en H2 pourrait être améliorée par la redirection de flux de cycle du Calvin-Benson-Bassham envers du système de nitrogénase qui catalyse la réduction des protons en H2. Ainsi, un PRK, phosphoribulose kinase, mutant « knock-out » de Rhodobacter capsulatus JP91 a été créé. L’analyse de la croissance sur des différentes sources de carbone a montré que ce mutant ne peut croître qu’avec l’acétate, sans toutefois produire d' H2. Un mutant spontané, YL1, a été récupéré qui a retenu l'cbbP (codant pour PRK) mutation d'origine, mais qui avait acquis la capacité de se développer sur le glucose et produire H2. Une étude de la production H2 sous différents niveaux d'éclairage a montré que le rendement d’YL1 était de 20-40% supérieure à la souche type sauvage JP91. Cependant, il n'y avait pas d'amélioration notable du taux de production de H2. Une étude cinétique a montré que la croissance et la production d'hydrogène sont fortement liées avec des électrons à partir du glucose principalement dirigés vers la production de H2 et la formation de la biomasse. Sous des intensités lumineuses faibles à intermédiaires, la production d'acides organiques est importante, ce qui suggère une nouvelle amélioration additionnel du rendement H2 pourrait être possible grâce à l'optimisation des processus. Dans une série d'expériences associées, un autre mutant spontané, YL2, qui a un phénotype similaire à YL1, a été testé pour la croissance dans un milieu contenant de l'ammonium. Les résultats ont montré que YL2 ne peut croître que avec de l'acétate comme source de carbone, encore une fois, sans produire de H2. Une incubation prolongée dans les milieux qui ne supportent pas la croissance de YL2 a permis l'isolement de deux mutants spontanés secondaires intéressants, YL3 et YL4. L'analyse par empreint du pied Western a montré que les deux souches ont, dans une gamme de concentrations d'ammonium, l'expression constitutive de la nitrogénase. Les génomes d’YL2, YL3 et YL4 ont été séquencés afin de trouver les mutations responsables de ce phénomène. Fait intéressant, les mutations de nifA1 et nifA2 ont été trouvés dans les deux YL3 et YL4. Il est probable qu'un changement conformationnel de NifA modifie l'interaction protéine-protéine entre NifA et PII protéines (telles que GlnB ou GlnK), lui permettant d'échapper à la régulation par l'ammonium, et donc d'être capable d'activer la transcription de la nitrogénase en présence d'ammonium. On ignore comment le nitrogénase synthétisé est capable de maintenir son activité parce qu’en théorie, il devrait également être soumis à une régulation post-traductionnelle par ammonium. Une autre preuve pourrait être obtenue par l'étude du transcriptome d’YL3 et YL4. Une première étude sur la production d’ H2 par YL3 et YL4 ont montré qu'ils sont capables d’une beaucoup plus grande production d'hydrogène que JP91 en milieu d'ammonium, qui ouvre la porte pour les études futures avec ces souches en utilisant des déchets contenant de l'ammonium en tant que substrats. Enfin, le reformage biologique de l'éthanol à H2 avec la bactérie photosynthétique, Rhodopseudomonas palustris CGA009 a été examiné. La production d'éthanol avec fermentation utilisant des ressources renouvelables microbiennes a été traitée comme une technique mature. Cependant, la plupart des études du reformage de l'éthanol à H2 se sont concentrés sur le reformage chimique à la vapeur, ce qui nécessite généralement une haute charge énergetique et résultats dans les émissions de gaz toxiques. Ainsi le reformage biologique de l'éthanol à H2 avec des bactéries photosynthétiques, qui peuvent capturer la lumière pour répondre aux besoins énergétiques de cette réaction, semble d’être plus prometteuse. Une étude précédente a démontré la production d'hydrogène à partir d'éthanol, toutefois, le rendement ou la durée de cette réaction n'a pas été examiné. Une analyse RSM (méthode de surface de réponse) a été réalisée dans laquelle les concentrations de trois facteurs principaux, l'intensité lumineuse, de l'éthanol et du glutamate ont été variés. Nos résultats ont montré que près de 2 moles de H2 peuvent être obtenus à partir d'une mole d'éthanol, 33% de ce qui est théoriquement possible.<br>Currently, renewable and environmentally friendly biofuels are under intensive study due to increasing health concerns and diminishing fossil fuels. H2 is one of the most promising candidates due to its unique characteristics, such as a high energy density and low to non-existent generation of pollutants. One attractive way to produce H2 is through photosynthetic bacteria which can capture light energy to drive H2 production with their nitrogenase system. The major aim of this study was to improve H2 yield of the purple non-sulfur photosynthetic bacteria using a combination of metabolic engineering and design of experiments. One hypothesis was that H2 yield could be improved by redirection of Calvin-Benson-Bassham cycle flux to the nitrogenase system which catalyzes the reduction of protons to H2. Thus, a PRK, phosphoribulose kinase, knock out mutant of Rhodobacter capsulatus JP91 was created. Analysis of growth with different carbon sources showed that this mutant could only grow in acetate medium without, however, producing any H2. A spontaneous mutant, YL1, was recovered which retained the original cbbP (encoding PRK) mutation, but which had gained the ability to grow on glucose and produce H2. A study of H2 production under different illumination levels showed that the yield of YL1 was 20-40% greater than the wild type JP91 strain. However, there was no appreciable improvement of the H2 production rate. A kinetic study showed that growth and hydrogen production are strongly linked with electrons from glucose being mostly directed to H2 production and biomass formation. Under low to intermediate light intensities, the production of organic acids was significant, suggesting further improvement of H2 yield is possible by process optimization. In a related series of experiments, another spontaneous mutant, YL2, which has a similar phenotype to YL1, was tested for growth in ammonium-containing media. The results showed that YL2 could only grow with acetate as carbon source, again, without producing any H2. Prolonged incubation in media not supporting growth of YL2 enabled the isolation of two interesting secondary spontaneous mutants, YL3 and YL4. Western blot analysis showed that both strains had constitutive nitrogenase expression under a range of ammonium concentrations. The genomes of YL2, YL3 and YL4 were sequenced in order to find the mutations responsible for this phenomenon. Interestingly, mutations of nifA1 and nifA2 were found in both YL3 and YL4. It is likely that a conformational change of NifA alters the protein-protein interaction between NifA and PII proteins (such as GlnB or GlnK), enabling it to escape regulation by ammonium and thus to be capable of activating nitrogenase transcription in the presence of ammonium. It is not clear how the synthesized nitrogenase is able to maintain its activity since in theory it should also be subject to posttranslational regulation by ammonium. Further evidence could be obtained by studying the transcriptome of YL3 and YL4. An initial study of H2 production by YL3 and YL4 showed that they are capable of much greater hydrogen production than JP91 in ammonium medium, which opens the door for future studies with these strains using ammonium-containing wastes as substrates. Finally, the biological reformation of ethanol to H2 with the photosynthetic bacterium, Rhodopseudomonas palustris CGA009 was examined. Ethanol production with microbial fermentation using renewable resources has been treated as a mature technique. However, most studies of the reformation of ethanol to H2 have focused on chemical steam reforming, which usually requires a high energy input and results in toxic gas emission. Thus biological reformation of ethanol to H2 with photosynthetic bacteria, which can capture light to meet the energy requirement of this reaction, seems to be more promising. A previous study had demonstrated hydrogen production from ethanol, however, the yield or the duration of this reaction were not examined. A RSM (response surface methodology) analysis was carried out in which three key factors, light intensity, ethanol and glutamate concentrations were varied. Our results showed that nearly 2 moles of H2 could be obtained from one mole of ethanol, 33% of what is theoretically possible.