62 research outputs found
Bradley Letter : August 15, 1864
No full textC. Elliot writes to Thomas about his sickness with typhus and his hope that Thomas will still "have a place for" him. This may be in regards to a job with the River Police, but this is uncertain
Creating Conjugated C−C Bonds between Commercial Carbon Electrode and Molecular Catalyst for Oxygen Reduction to Hydrogen Peroxide
No full textImmobilizing molecular catalysts on electrodes is vital for electrochemical applications. However, creating robust electrode-catalyst interactions while maintaining good catalytic performance and rapid electron transfer is challenging. Here, without introducing any foreign elements, we show a bottom-up synthetic approach of constructing the conjugated C−C bond between the commercial Vulcan carbon electrode and an organometallic catalyst. Characterization results from FTIR, XPS, aberration-corrected TEM and EPR confirmed the successful and uniform heterogenization of the complex. The synthesized Vulcan-LN4−Co catalyst is highly active and selective in the oxygen reduction reaction in neutral media, showing an 80 % hydrogen peroxide selectivity and a 0.72 V (vs. RHE) onset potential which significantly outperformed the homogenous counterpart. Based on single-crystal XRD and NMR data, we built a model for density functional theory calculations which showed a nearly optimal binding energy for the *OOH intermediate. Our results show that the direct conjugated C−C bonding is an effective approach for heterogenizing molecular catalysts on carbon, opening new opportunities for employing molecular catalysts in electrochemical applications.ChemE/Materials for Energy Conversion and Storag
Materials and techniques of Art Nouveau architecture in Italy and Portugal: a first insight for an European route to consistent restoration
No full textThe results of the investigations on building materials and techniques of Casa Major Pessoa, a typical Art
Nouveau construction in Aveiro (Portugal), and two coeval Art Nouveau buildings in Bologna (Italy) are presented
as a methodological contribution to the restoration of this kind of buildings. This is the first step to
ascertain the existence of a common thread between local materials, technologies and architecture in European
countries at the same period. A holistic approach was adopted: materials were investigated along with
architectural, structural and technological features, in order to achieve a first insight into the Art Nouveau
architecture in Europe in particular for its consistent restoration without loss of historical memory
Towards Higher NH<sub>3</sub> Faradaic Efficiency: Selective-Poisoning of HER Active Sites by Co-Feeding CO in NO Electroreduction**
No full textDirect electroreduction of nitric oxide offers a promising avenue to produce valuable chemicals, such as ammonia, which is an essential chemical to produce fertilizers. Direct ammonia synthesis from NO in a polymer electrolyte membrane (PEM) electrolyzer is advantageous for its continuous operation and excellent mass transport characteristics. However, at a high current density, the faradaic efficiency of NO electroreduction reaction is limited by the competing hydrogen evolution reaction (HER). Herein, we report a CO-mediated selective poisoning strategy to enhance the faradaic efficiency (FE) towards ammonia by suppressing the HER. In the presence of only NO at the cathode, Pt/C and Pd/C catalysts showed a lower FE towards NH3 than to H2 due to the dominating HER. Cu/C catalyst showed a 78 % FE towards NH3 at 2.0 V due to the stronger binding affinity to NO* compared to H*. By co-feeding CO, the FE of Cu/C catalyst towards NH3 was improved by 12 %. More strikingly, for Pd/C, the FE towards NH3 was enhanced by 95 % with CO co-feeding, by effectively suppressing HER. This is attributed to the change of the favorable surface coverage resulting from the selective and competitive binding of CO* to H* binding sites, thereby improving NH3 selectivity.ChemE/Catalysis EngineeringLarge Scale Energy Storag
Opinions des anciens sur les Juifs /
No full textMystification; the real author is Paul Henri Thiry baron d'HolbachPrinted in Amsterdam (Weller) by Marc Michel Rey?Vingerafdruk: 176908 - b1 A rseqReflexions impartiales sur l'évangile [p. 129-238]Lammens, Pierre Philippe ConstantHerkomst: Vignet Ex libris C. van HultehmHerkomst: Vignet Ex libris à mad.e de BeaumanoirWeller, E.O. Die falschen und fingirten Druckorte, II: Enthaltend die französischen Schriften (1864), p. 183Europeana-GoogleBook
Class consciousness and migrant workers : dock workers of Durban
No full textDespite the enormous apparatus of control at the disposal of employers
and the state in South Africa, working class activity has not been eliminated
nor organization erased. African migrant workers, such as those employed
in the Durban docks, have held a leading position within the African working
class for decades, absorbing the lessons of past struggles and putting forward
demands which have led strike movements. These struggles demonstrate the
uncompromising hostility of African workers to their class and national oppres-
sion. With the growth of capital in South Africa an increase in class
exploitation has been accompanied by intensified national oppression; the
rule over African workers being enforced through vagrant, master and servant,
and pass laws wh ich reproduce a cheap migrant labour force.
Dock workers, for more than a century migrant workers, have shown a
capacity for resistance in the city equal or higher than the level of class action
by 'settled' urban workers. Their resilience is explained by their concentra-
tion and commanding position in the labour process of the docks. During
strikes the workers have laid claim to work and residence in towns in opposition
to the employer and state strategy of expell ing strikers from th e urban centres.
Decasualization has been introduced as a 'repressive reform' to reassert
the control of the employers over an increasingly active workforce. Ironically,
it has b~en accompanied by increasing priority to the development of contract
labour in the docks and has also not eliminated the high turnover of workers nor
the insecurity of employment.
The consciousness of the dock workers has been shaped by the harsh
discipline of capitalist production, national oppression, and the daily
experience of international communications. These factors, combined with
a long tradition of resistance, have encouraged the formation of a class con-
scious section of the African proletariat
Prize the doubt : the life and work of Francis William Newman.
No full textAvailable from British Library Document Supply Centre- DSC:DX180157 / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo
Systematik, Taxonomie, Phylogenie und Zoogeographie des Capoeta damascina-Artenkomplexes (Pisces: Teleostei: Cyprinidae) auf der Grundlage vergleichend-morphologischer und molekulargenetischer Untersuchungen
No full textDer Damaskus-Weißling Capoeta damascina (Pisces: Teleostei: Cyprinidae) kommt in der Levante, in Mesopotamien und in Teilen der Türkei und des Iran vor. Dort ist er eine der häufigsten Fischarten. Aufgrund der Trockenheit dieser Region besteht der Lebensraum dieser Art aus vielen von einander isolierten Gewässern. Vor der hier vorgelegten Studie war nicht klar, ob es sich bei C. damascina um eine Art handelt, oder aber um einen Komplex nah verwandter Arten, die sich durch hohe intraspezifische und geringe interspezifische Variabilität auszeichnen. Ziel der vorliegenden Untersuchungen war es, anhand morphologischer und molekulargenetischer Daten die phylogenetische Position des C. damascina-Artenkomplexes zu ermitteln und die Verwandtschaftsbeziehungen der Arten untereinander zu klären. Um die Arten gegeneinander abzugrenzen und wichtige diagnostische Merkmale zu ermitteln, wurden Fischsammlungen großer europäischer Museen vergleichend-morphologisch untersucht. Dabei galt den Typen der nominellen Arten dieses Komplexes besonderes Augenmerk. Zur Klärung der Verwandtschaftsbeziehungen wurden Sequenzen der mitochondrialen Cytochrom-c-Oxidase (COI, n = 103) und der zwei benachbarten variablen Regionen (D1-D2) des nukleären 28S-rRNA-Gens (LSU, n = 65) mit Hilfe unterschiedlicher phylogenetischer Rekonstruktionsalgorithmen ausgewertet. Als Ergebnis werden innerhalb des C. damascina-Artenkomplexes die folgenden sechs Arten als gültig anerkannt: Capoeta buhsei, C. caelestis, C. damascina, C. saadii, C. umbla und die bisher unbeschriebene Art Capoeta sp. 1. Die Analyse der morphometrischen und meristischen Daten zeigt ein hohes Maß an phenotypischer Variabilität zwischen den unterschiedlichen Populationen derselben Art, sowie zwischen den verschiedenen Arten. Dieses Phänomen ist genetischen Faktoren, dem Einfluss von Umweltbedingungen bzw. einer Kombination aus beidem zu erklären. Die phylogenetischen Analysen zeigen zwei genetische Linien innerhalb des C. damascina-Artenkomplexes: eine westliche Linie mit den Arten C. caelestis, C. damascina und C. umbla; so wie eine östliche Linie mit den Arten C. buhsei, C. saadii und Capoeta sp. 1. Die enge Verwandtschaft zwischen C. damascina und C. umbla zeigt sich unter anderem dadurch, dass ein Exemplar von C. damascina aus dem Euphrat den selben COI-Haplotypen aufweist wie ein Exemplar von C. umbla aus dem Tigris. Hierfür gibt es drei mögliche Erklärungen: Mitochondriale Introgression, nahe zurückliegende Artbildung oder eine Kombination aus beidem. Die Ergebnisse zeigen, dass es sich bei den sechs genannten Taxa um junge Arten handelt und ihre Entstehung und heutige Verbreitung im Wesentlichen durch pleistozäne Ereignisse geprägt wurde. Die Besiedlung des Iran erfolgte vermutlich während einer der früheren pleistozänen Meeresspiegeltiefstände und führte zur Abspaltung der östlichen Linie von der mesopotamischen Ausgangspopulation. Die östliche Linie konnte in humiden Phasen des Pleistozäns die verschiedenen Flusssysteme des südlichen und zentralen Iran besiedeln wo sich die Arten C. buhsei, C. saadii und Capoeta sp. 1 bildeten. Nach der Abspaltung der östlichen Linie breitete sich die westliche Linie von Mesopotamien in die Levante aus. Dies geschah ebenfalls während des Pleistozäns, als die Oberläufe der westlichen Zuflüsse des Euphrats mit dem Ceyhan verbunden waren. Vom Ceyhan aus erfolgte die Ausbreitung in die Flüsse der südlichen Türkei, die zu Perioden niedriger Meeresspiegelstände über die verlängerten Unterläufe miteinander verbunden waren. Auf diese Weise wurde der Seyhan/Göksu besiedelt und die Art C. caelestis entstand. Die Schwesterpopulation differenzierte sich in die Arten C. damascina und C. umbla. Sehr wahrscheinlich besiedelte C. damascina während des späten Pleistozäns die Levante und die südliche Türkei. Dies wird durch die geringe genetische Differenzierung der Art belegt. Direkte Süßwasserverbindungen, die als Ausbreitungsroute für C. damascina zwischen den Gewässersystemen der Levante dienten, existierten zu Zeiten niedriger Meeresspiegelstände. Die hier vorgelegte Arbeit beinhaltet eine detaillierte Neubewertung des taxonomischen Status der behandelten Arten. Sechs nah verwandte Arten werden als gültig anerkannt. Das rezente Verbreitungsmuster dieser Arten wird vor dem Hintergrund der geologischen Entwicklung des Verbreitungsgebietes, ökologischer Faktoren so wie der Verwandtschaftsbeziehungen zwischen den Arten und ihrer Evolutionsgeschichte erklärt.Capoeta damascina (Teleostei: Cyprinidae) is one of the most common freshwater fish species, found throughout the Levant, Mesopotamia, Turkey and Iran. According to the state of knowledge prior to this study, C. damascina, which is distributed over a wide range of isolated water bodies, was not a well-defined species. It was questionable whether it represents a single species or a complex of closely related species with high intraspecific and comparatively low interspecific variability. The goal of this study was to investigate the taxonomy, systematic position of the C. damascina species complex and the phylogenetic relationships among its members, based on morphological features as well as molecular phylogeny. Samples obtained from throughout the geographic range of this species complex were subjected to comparative morphological analyses in order to define, properly diagnose and separate species within the C. damascina complex. To elucidate phylogenetic relationships among members of the C. damascina species complex, samples were subjected to genetic analyses, using two molecular markers targeting the mitochondrial cytochrome oxidase I (COI, n = 103) and the two adjacent divergence regions (D1-D2) of the nuclear 28S rRNA genes (LSU, n = 65). Based on morphological and molecular genetic data, six closely related species were recognized within the C. damascina complex: C. buhsei, C. caelestis, C. damascina, C. saadii, C. umbla and an undescribed species, Capoeta sp.1. Analyses of the morphometric and meristic data obtained in this study revealed phenotypic variability among the various populations within a species and among the different species. Such differences in morphological characters reflect genetic differences, environmentally induced phenotypic variation or both, as the meristic phenotype of fish is sometimes a consequence of environmental parameters acting on the genotype. Based on phylogenetic analyses, two main lineages were identified within the C. damascina species complex: a western lineage represented by C. caelestis, C. damascina and C. umbla and an eastern lineage represented by C. buhsei, C. saadii and Capoeta sp.1. The close phylogenetic relationships between C. damascina and C. umbla and the sharing of same haplotypes between one specimen of C. damascina from Euphrates and another of C. umbla from Tigris reflect one of three possibilites: recent speciation, mitochondrial introgression or a combination of both. The results obtained in this study indicate that speciation of the above-mentioned six taxa is quite recent and that their dispersal and present-day distribution can be related to Pleistocene events. The drying out of the Persian Gulf, probably during one of the first glacials of the Pleistocene, led the ancestor of the C. damascina species complex in Mesopotamia to reach the rivers of the Gulf and of Hormuz basins and differentiate there, giving rise to the eastern lineage (ancestor of C. buhsei, C. saadii and Capoeta sp.1). As connections presumably existed among the different river drainages and basins in Iran during the wet periods of the Pleistocene, the ancestor of C. buhsei, C. saadii and Capoeta sp.1 was subsequently able to colonize the various Iranian drainages and differentiate there, giving rise to C. buhsei, C. saadii and Capoeta sp.1. After the separation from the eastern lineage, the western lineage, represented by the ancestor of C. damascina, C. umbla and C. caelestis, most likely reached the Levant from the Tigris-Euphrates system during the Pleistocene glacials, when river connections existed in the regions of the upper courses of Ceyhan Nehri (southern Turkey) and some western affluents to the Euphrates. From Ceyhan Nehri, it dispersed into other rivers in southern Turkey during Pleistocene periods of low sea levels until it reached Göksu Nehri and evolved into C. caelestis. The sister population differentiated into C. damascina and C. umbla. Based on the results obtained in this study, it is likely that C. damascina colonized the Levant and southern Turkey during the Pleistocene glacials. This is well supported by the low genetic variability among the C. damascina populations. Direct connections existed among the river drainages in the Levant during the Pleistocene periods of low sea level, thus serving as a pathway for the dispersal of C. damascina. The results of this study provide a coherent picture of the taxonomic position, phylogenetic relationships and evolutionary history of the C. damascina species complex and explain present patterns of distribution considering paleogeographic events
Canon Barnett and the first thirty years of Toynbee Hall
No full textPhDThis thesis is a study of the changing role which Toynbee
Hall, the first university settlement, played in East London between
1884 and 1914. The first chapter presents a brief biography of
Sainiel Augustus Barnett, the founder and first warden of the
settlement, and analyzes his social thought in relation to the
beliefs which were current in Britain during the period. The
second chapter discusses the founding of the settlement, its organization, structure and the aims which underlay its early work. The
third chapter, concentrating on three residents, C.R. Ashbee, .H.
Beveridge and T. Edmund Harvey, shows the way in which subsequent
settlement workers reformulated these aims In accordance with their
own social and economic views. The subsequent chapters discuss the
accomplishments of the settlement in various fields. The fourth
shows that Toynbee Hall's educational program, which was largely an
attempt to work out Matthew Arnold's theory of culture, left little
impact on the life of East London. The fifth chapter discusses the
settlement residents' ineffectual attempts to establish contact with
working men's organizations. The final chapter seeks to demonstrate
that In the field of philanthropy the residents were far more successful than in any other sphere in adapting the settlement to changing
social thought
A function of thymine DNA glycosylase-initiated DNA repair in maintaining epigenome stability
No full textThe Thymine DNA Glycosylase (TDG) was initially discovered by its ability to excise the deamination
products of cytosine and 5-methylcytosine (5-mC), and therefore thought to initiate base excision
repair (BER) of the resulting G•U and G•T mismatches. Later, TDG was also found to act in concert
with transcription factors in the regulation of gene expression.
With its apparently two-sided nature, TDG has riddled researchers for many years and the stimuli
and interactions that control TDG function are still under investigation. The aim of my thesis was to
dissect the role of TDG in DNA repair with a focus on its regulation by post-translational modification,
and to investigate how TDG-initiated BER contributes to epigenetic stability at CpG islands (CGIs)
during cell differentiation.
Both described functions of TDG, in DNA repair and in the regulation of gene expression, require its
post-translational modification and non-covalent interaction with the small ubiquitin-like modifiers,
SUMO1 and SUMO2/3. Extensive biochemical studies by our laboratory have shown that
SUMOylation of TDG may induce its dissociation from the abasic (AP-) site after base excision.
However, in vivo evidence corroborating an involvement of SUMOylation in TDG-dependent BER has
been pending and the function of non-covalent SUMO-binding has remained elusive. I thus
generated a Fluorescence Resonance Energy Transfer (FRET) system to monitor the interaction
between TDG and SUMO1 or SUMO3 in cells. I was able to confirm a modulation of the SUMO1-TDG
interaction dynamics in response to DNA damage, whereas the interaction with SUMO3 remained
unaffected, suggesting that modification by SUMO3 might regulate TDG function in a context other
than DNA repair.
To investigate the biological function of TDG genetically, we generated a Tdg knockout mouse. In
contrast to any other known DNA glycosylase, deletion of Tdg caused embryonic lethality. Further
characterization of MEFs isolated from TDG-proficient and -deficient embryos revealed no evidence
for a DNA repair defect, but a significant number of misregulated genes in differentiated Tdg-/- cells,
as well as a loss of active histone marks, gain of repressive histone modifications and an
accumulation of 5-mC at CGI promoters. A phenotype we did not observe in embryonic stem cells.
From these data, we proposed a dual function of TDG in maintaining active chromatin states at
promoters in differentiating cells, first by structurally coordinating histone modifying enzymes and
second by counteracting errors of the DNA methylation machinery by initiating repair of aberrantly
methylated cytosines in CGIs. Consistent with a TDG-dependent engagement of DNA repair at such
sites, we found BER factors to associate with these promoters and DNA repair intermediates to
accumulate in differentiating cells in a TDG dependent manner.
To investigate further how TDG is involved in DNA methylation control, we mapped DNA methylation
in the genomes of TDG-proficient and -deficient mouse embryonic stem cells (ESCs), neuronal
progenitor cells (NPs) and MEFs and found differential methylation to arise only with differentiation.
Further characterization of the resulting differentially methylated regions (DMRs) revealed that those
overlapping with a CGI were almost exclusively hypomethylated in TDG-deficient compared to -proficient cells,
reflecting a failure to establish methylation at these CGIs during differentiation. In
search of the reason for this failure in a 24 h differentiation timecourse, we found global 5-mC levels
to rise with differentiation in cells lacking TDG activity, in parallel to the generation of the final
products of TET-protein catalyzed 5-mC oxidation, 5-formylcytosine (5-fC) and 5-carboxylcytosine (5-
caC), the latter two of which are proposed intermediates of active DNA demethylation and
substrates for TDG. Differentiation thus appeared to induce methylation but also the intermediates
of active demethylation. We therefore analyzed 5-mC and 5-caC levels at the CGI DMRs and found
both to rise with differentiation in wildtype cells, suggesting that the loss of pluripotency induces a
cycle of DNA methylation and demethylation specific CGIs. In Tdg knockout cells, though, this
induction appeared to fail whereas in cells expressing a catalytically dead mutant TDG (TDG-cat), the
cycle of methylation and demethylation was induced but blocked by the inability of TDG-cat to excise
5-caC.
Taken together, in collaboration with colleagues from different laboratories I was able to show that
differentiation triggers a state of high epigenetic plasticity at these CGIs and that catalytically active
TDG is required to maintain an equilibrium of DNA methylation and demethylation. The imbalance of
epigenetic marks resulting from knockout of TDG disrupts gene expression programs and the
accumulation of aberrations eventually leads to loss of viability on the cellular and on the organismic
level
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