Showing papers by "University of Konstanz published in 2004"
TL;DR: This work analyzed the structural variations, which are the basis of functional diversification, as well as the genomic organization of the S100 family in human and compared it with the S 100 repertoires in mouse and rat, and identified evolutionary related subgroups of S100 proteins within the three species.
824 citations
TL;DR: Assessing early perceptual stimulusprocessing, threatening faces elicited an early posterior negativity compared with nonthreatening neutral or friendly expressions, and at later stages of stimulus processing, facial threat also elicited augmented late positive potentials relative to the other facial expressions, indicating the more elaborate perceptual analysis of these stimuli.
Abstract: Threatening, friendly, and neutral faces were presented to test the hypothesis of the facilitated perceptual processing of threatening faces. Dense sensor event-related brain potentials were measured while subjects viewed facial stimuli. Subjects had no explicit task for emotional categorization of the faces. Assessing early perceptual stimulus processing, threatening faces elicited an early posterior negativity compared with nonthreatening neutral or friendly expressions. Moreover, at later stages of stimulus processing, facial threat also elicited augmented late positive potentials relative to the other facial expressions, indicating the more elaborate perceptual analysis of these stimuli. Taken together, these data demonstrate the facilitated perceptual processing of threatening faces. Results are discussed within
741 citations
TL;DR: It is shown that Arabidopsis thaliana reacts to LPS with a rapid burst of NO, a hallmark of innate immunity in animals and contributes toward the activation of plant defense responses.
Abstract: Lipopolysaccharides (LPS) are cell-surface components of Gram-negative bacteria and are microbe-/pathogen-associated molecular patterns in animal pathosystems. As for plants, the molecular mechanisms of signal transduction in response to LPS are not known. Here, we show that Arabidopsis thaliana reacts to LPS with a rapid burst of NO, a hallmark of innate immunity in animals. Fifteen LPS preparations (among them Burkholderia cepacia, Pseudomonas aeruginosa, and Erwinia carotovora) as well as lipoteichoic acid from Gram-positive Staphylococcus aureus were found to trigger NO production in suspension-cultured Arabidopsis cells as well as in leaves. NO was detected by confocal laser-scanning microscopy in conjunction with the fluorophore 4-amino-5-methylamino-2′,7′-difluorofluorescein diacetate, by electron paramagnetic resonance, and by a NO synthase (NOS) assay. The source of NO was addressed by using T-DNA insertion lines. Interestingly, LPS did not activate the pathogen-inducible varP NOS, but AtNOS1, a distinct NOS previously associated with hormonal signaling in plants. A prominent feature of LPS treatment was activation of defense genes, which proved to be mediated by NO. Northern analyses and transcription profiling by using DNA microarrays revealed induction of defense-associated genes both locally and systemically. Finally, AtNOS1 mutants showed dramatic susceptibility to the pathogen Pseudomonas syringae pv. tomato DC3000. In sum, perception of LPS and induction of NOS contribute toward the activation of plant defense responses.
629 citations
TL;DR: Data suggest that a quick glimpse of emotionally relevant stimuli appears sufficient to tune the brain for selective perceptual processing when pictures are presented only briefly.
Abstract: Recent event-related potential (ERP) studies revealed the selective processing of affective pictures. The present study explored whether the same phenomenon can be observed when pictures are presented only briefly. Toward this end, pleasant, neutral, and unpleasant pictures from the International Affective Pictures Series were presented for 120 ms while event related potentials were measured by dense sensor arrays. As observed for longer picture presentations, brief affective pictures were selectively processed. Specifically, pleasant and unpleasant pictures were associated with an early endogenous negative shift over temporo-occipital sensors compared to neutral images. In addition, affective pictures elicited enlarged late positive potentials over centro-parietal sensor sites relative to neutral images. These data suggest that a quick glimpse of emotionally relevant stimuli appears sufficient to tune the brain for selective perceptual processing.
623 citations
TL;DR: C. albicans induces immunosuppression through TLR2-derived signals that mediate increased IL-10 production and survival of Treg cells, which represents a novel mechanism in the pathogenesis of fungal infections.
Abstract: Toll-like receptor (TLR) 2 and TLR4 play a pivotal role in recognition of Candida albicans. We demonstrate that TLR2(-/-) mice are more resistant to disseminated Candida infection, and this is associated with increased chemotaxis and enhanced candidacidal capacity of TLR2(-/-) macrophages. Although production of the proinflammatory cytokines TNF, IL-1alpha, and IL-1beta is normal, IL-10 release is severely impaired in the TLR2(-/-) mice. This is accompanied by a 50% decrease in the CD4+CD25+ regulatory T (Treg) cell population in TLR2(-/-) mice. In vitro studies confirmed that enhanced survival of Treg cells was induced by TLR2 agonists. The deleterious role of Treg cells on the innate immune response during disseminated candidiasis was underscored by the improved resistance to this infection after depletion of Treg cells. In conclusion, C. albicans induces immunosuppression through TLR2-derived signals that mediate increased IL-10 production and survival of Treg cells. This represents a novel mechanism in the pathogenesis of fungal infections.
610 citations
TL;DR: Results indicate that NET is a promising approach for the treatment of PTSD for refugees living in unsafe conditions.
Abstract: Little is known about the usefulness of psychotherapeutic approaches for traumatized refugees who continue to live in dangerous conditions. Narrative exposure therapy (NET) is a short-term approach based on cognitive-behavioral therapy and testimony therapy. The efficacy of narrative exposure therapy was evaluated in a randomized controlled trial. Sudanese refugees living in a Ugandan refugee settlement (N = 43) who were diagnosed as suffering from posttraumatic stress disorder (PTSD) either received 4 sessions of NET, 4 sessions of supportive counseling (SC), or psychoeducation (PE) completed in 1 session. One year after treatment, only 29% of the NET participants but 79% of the SC group and 80% of the PE group still fulfilled PTSD criteria. These results indicate that NET is a promising approach for the treatment of PTSD for refugees living in unsafe conditions.
584 citations
TL;DR: Individual gene trees for these three genes and a concatenated dataset support the hypothesis that the fish-specific genome duplication event took place after the split of the Acipenseriformes and the Semionotiformes from the lineage leading to teleost fish but before the divergence of Osteoglossiformes.
Abstract: For many genes, ray-finned fish (Actin- opterygii) have two paralogous copies, where only one ortholog is present in tetrapods. The discovery of an additional, almost-complete set of Hox clusters in teleosts (zebrafish, pufferfish, medaka, and cichlid) but not in basal actinopterygian lineages (Polypterus) led to the formulation of the fish-specific genome duplication hypothesis. The phylogenetic timing of this genome duplication during the evolution of ray- finned fish is unknown, since only a few species of basal fish lineages have been investigated so far. In this study, three nuclear genes (fzd8, sox11, tyrosin- ase) were sequenced from sturgeons (Acipenseri- formes), gars (Semionotiformes), bony tongues (Osteoglossomorpha), and a tenpounder (Elopo- morpha). For these three genes, two copies have been described previously teleosts (e.g., zebrafish, puffer- fish), but only one orthologous copy is found in tetrapods. Individual gene trees for these three genes and a concatenated dataset support the hypothesis that the fish-specific genome duplication event took place after the split of the Acipenseriformes and the Semionotiformes from the lineage leading to teleost fish but before the divergence of Osteoglossiformes. If these three genes were duplicated during the pro- posed fish-specific genome duplication event, then this event separates the species-poor early-branching lineages from the species-rich teleost lineage. The additional number of genes resulting from this event might have facilitated the evolutionary radiation and the phenotypic diversification of the teleost fish.
572 citations
TL;DR: Knowing the geometrical limits of ECM binding sites required for cell attachment and spreading is essential for an understanding of cell adhesion and migration, and for the design of artificial surfaces that optimally interact with cells in a living tissue.
Abstract: Cell adhesion, spreading and migration require the dynamic formation and dispersal of contacts with the extracellular matrix (ECM). In vivo, the number, availability and distribution of ECM binding sites dictate the shape of a cell and determine its mobility. To analyse the geometrical limits of ECM binding sites required for cell attachment and spreading, we used microcontact printing to produce regular patterns of ECM protein dots of defined size separated by nonadhesive regions. Cells cultured on these substrata adhere to and spread on ECM regions as small as 0.1 microm2, when spacing between dots is less than 5 microm. Spacing of 5-25 microm induces a cell to adapt its shape to the ECM pattern. The ability to spread and migrate on dots > or =1 microm2 ceases when the dot separation is > or =30 microm. The extent of cell spreading is directly correlated to the total substratum coverage with ECM-proteins, but irrespective of the geometrical pattern. An optimal spreading extent is reached at a surface coating above 15%. Knowledge of these geometrical limits is essential for an understanding of cell adhesion and migration, and for the design of artificial surfaces that optimally interact with cells in a living tissue.
421 citations
TL;DR: There is a clear dose-effect relationship between traumatic exposure and PTSD in the studied populations with high levels of traumatic events, and it is probable that any individual could develop PTSD regardless of other risk-factors once the trauma load reaches a certain threshold.
Abstract: Background
Political instability and the civil war in Southern Sudan have resulted in numerous atrocities, mass violence, and forced migration for vast parts of the civilian population in the West Nile region. High exposure to traumatic experiences has been particularly prominent in the Ugandan and Sudanese of the West Nile Region, representing an indication of the psychological strain posed by years of armed conflict.
417 citations
TL;DR: In this article, the impact of foreign bank entry on banking efficiency in Australia during the post-deregulation period 1988-2001 was investigated using Data Envelopment Analysis, Malmquist Indices and stochastic frontier analysis.
Abstract: This study considers the impact of foreign bank entry on banking efficiency in Australia during the post-deregulation period 1988–2001. Using Data Envelopment Analysis, Malmquist Indices and stochastic frontier analysis, we find foreign banks more efficient than domestic banks, which however did not result in superior profits. Major Australian banks have used size as a barrier to entry to new entrants. Furthermore, bank efficiency has increased post-deregulation and the competition resulting from diversity in bank types was important to prompt efficiency improvements. Finally, the recession of the early 1990s resulted in a distinct shift in the process of efficiency changes.
408 citations
TL;DR: In this paper, a review summarises the theoretical work as well as the attempts to prepare carbon(IV) nitrides by chemical and physical vapour deposition, and in particular on the concepts and results of bulk synthesis routes.
TL;DR: The results suggest that microbial reduction of humic acid and subsequent chemical reduction of poorly soluble iron(III) minerals by the reduced humic acids represents an important path of electron flow in anoxic natural environments such as freshwater sediments.
TL;DR: Good quantitative agreement is found between the experimental observations and microscopic decoherence theory of matter wave interferometer experiments in which C70 molecules lose their quantum behaviour by thermal emission of radiation.
Abstract: Emergent quantum technologies have led to increasing interest in decoherence—the processes that limit the appearance of quantum effects and turn them into classical phenomena. One important cause of decoherence is the interaction of a quantum system with its environment, which ‘entangles’ the two and distributes the quantum coherence over so many degrees of freedom as to render it unobservable. Decoherence theory1,2,3,4 has been complemented by experiments using matter waves coupled to external photons5,6,7 or molecules8, and by investigations using coherent photon states9, trapped ions10 and electron interferometers11,12. Large molecules are particularly suitable for the investigation of the quantum–classical transition because they can store much energy in numerous internal degrees of freedom; the internal energy can be converted into thermal radiation and thus induce decoherence. Here we report matter wave interferometer experiments in which C70 molecules lose their quantum behaviour by thermal emission of radiation. We find good quantitative agreement between our experimental observations and microscopic decoherence theory. Decoherence by emission of thermal radiation is a general mechanism that should be relevant to all macroscopic bodies.
TL;DR: Nitrate tolerance is mediated, at least in significant part, by inhibition of vascular ALDH-2 and that mitochondrial ROS contribute to this inhibition, and GTN tolerance may be viewed as a metabolic syndrome characterized by mitochondrial dysfunction.
Abstract: Recent studies suggest that mitochondrial aldehyde dehydrogenase (ALDH-2) plays a central role in the process of nitroglycerin (glyceryl trinitrate, GTN) biotransformation in vivo and that its inhibition accounts for mechanism-based tolerance in vitro. The extent to which ALDH-2 contributes to GTN tolerance (impaired relaxation to GTN) and cross-tolerance (impaired endothelium-dependent relaxation) in vivo remain to be elucidated. Rats were treated for three days with GTN. Infusions were accompanied by decreases in vascular ALDH-2 activity, GTN biotransformation, and cGMP-dependent kinase (cGK-I) activity. Further, whereas in control vessels, multiple inhibitors and substrates of ALDH-2 reduced both GTN-stimulation of cGKI and GTN-induced vasodilation, these agents had little effect on tolerant vessels. A state of functional tolerance (in the GTN/cGMP pathway) was recapitulated in cultured endothelial cells by knocking down mitochondrial DNA (rho(0) cells). In addition, GTN increased the production of reactive oxygen species (ROS) by mitochondria, and these increases were associated with impaired relaxation to acetylcholine. Finally, antioxidants/reductants decreased mitochondrial ROS production and restored ALDH-2 activity. These observations suggest that nitrate tolerance is mediated, at least in significant part, by inhibition of vascular ALDH-2 and that mitochondrial ROS contribute to this inhibition. Thus, GTN tolerance may be viewed as a metabolic syndrome characterized by mitochondrial dysfunction.
TL;DR: Extended x-ray absorption fine structure measurements were performed on frozen hydrated samples of the cadmium (Cd)/zinc (Zn) hyperaccumulator Thlaspi caerulescens (Ganges ecotype) after 6 months of Zn2+ treatment with and without addition of Cd2+.
Abstract: Extended x-ray absorption fine structure measurements were performed on frozen hydrated samples of the cadmium (Cd)/zinc (Zn) hyperaccumulator Thlaspi caerulescens (Ganges ecotype) after 6 months of Zn2+ treatment with and without addition of Cd2+. Ligands depended on the metal and the function and age of the plant tissue. In mature and senescent leaves, oxygen ligands dominated. This result combined with earlier knowledge about metal compartmentation indicates that the plants prefer to detoxify hyperaccumulated metals by pumping them into vacuoles rather than to synthesize metal specific ligands. In young and mature tissues (leaves, petioles, and stems), a higher percentage of Cd was bound by sulfur (S) ligands (e.g. phytochelatins) than in senescent tissues. This may indicate that young tissues require strong ligands for metal detoxification in addition to the detoxification by sequestration in the epidermal vacuoles. Alternatively, it may reflect the known smaller proportion of epidermal metal sequestration in younger tissues, combined with a constant and high proportion of S ligands in the mesophyll. In stems, a higher proportion of Cd was coordinated by S ligands and of Zn by histidine, compared with leaves of the same age. This may suggest that metals are transported as stable complexes or that the vacuolar oxygen coordination of the metals is, like in leaves, mainly found in the epidermis. The epidermis constitutes a larger percentage of the total volume in leaves than in stems and petioles. Zn-S interaction was never observed, confirming earlier results that S ligands are not involved in Zn resistance of hyperaccumulator plants.
TL;DR: This work discusses the main factors that bring about catalysis, promote specificity and determine the selective transfer of electrons to electron transferring flavoprotein in medium chain acyl-CoA dehydrogenase.
Abstract: Acyl-CoA dehydrogenases constitute a family of flavoproteins that catalyze the α,β-dehydrogenation of fatty acid acyl-CoA conjugates While they differ widely in their specificity, they share the same basic chemical mechanism of α,β-dehydrogenation Medium chain acyl-CoA dehydrogenase is probably the best-studied member of the class and serves as a model for the study of catalytic mechanisms Based on medium chain acyl-CoA dehydrogenase we discuss the main factors that bring about catalysis, promote specificity and determine the selective transfer of electrons to electron transferring flavoprotein The mechanism of α,β-dehydrogenation is viewed as a process in which the substrate αC-H and βC-H bonds are ruptured concertedly, the first hydrogen being removed by the active center base Glu376-COO– as an H+, the second being transferred as a hydride to the flavin N(5) position Hereby the pKa of the substrate αC-H is lowered from > 20 to ≈ 8 by the effect of specific hydrogen bonds Concomitantly, the pKa of Glu376-COO– is also raised to 8–9 due to the decrease in polarity brought about by substrate binding The kinetic sequence of medium chain acyl-CoA dehydrogenase is rather complex and involves several intermediates A prominent one is the molecular complex of reduced enzyme with the enoyl-CoA product that is characterized by an intense charge transfer absorption and serves as the point of transfer of electrons to the electron transferring flavoprotein These views are also discussed in the context of the accompanying paper on the three-dimensional properties of acyl-CoA dehydrogenases
TL;DR: L-ficolin specifically binds to lipoteichoic acid (LTA), a cell wall component found in all Gram-positive bacteria, and corresponding levels of C4 turnover were observed on LTA purified from other clinically important bacteria.
Abstract: The lectin pathway of complement is activated when a carbohydrate recognition complex and associated serine proteases binds to the surface of a pathogen. Three recognition subcomponents have been shown to form active initiation complexes: mannan-binding lectin (MBL), L-ficolin, and H-ficolin. The importance of MBL in antimicrobial host defense is well recognized, but the role of the ficolins remains largely undefined. This report shows that L-ficolin specifically binds to lipoteichoic acid (LTA), a cell wall component found in all Gram-positive bacteria. Immobilized LTA from Staphylococcus aureus binds L-ficolin complexes from sera, and these complexes initiate lectin pathway-dependent C4 turnover. C4 activation correlates with serum L-ficolin concentration, but not with serum MBL levels. L-ficolin binding and corresponding levels of C4 turnover were observed on LTA purified from other clinically important bacteria, including Streptococcus pyogenes and Streptococcus agalactiae. None of the LTA preparations bound MBL, H-ficolin, or the classical pathway recognition molecule, C1q.
TL;DR: In this paper, the lattice dynamics in gold nanoparticles in water following excitation with intense femtosecond laser pulses were examined. Butler et al. showed that at higher temperatures the lattices showed a loss of long-range order due to pre-melting of the particles.
Abstract: Pulsed x-ray scattering is used to examine the lattice dynamics in gold nanoparticles in water following excitation with intense femtosecond laser pulses. At lower excitation power the initial lattice heating is followed by cooling on the nanosecond time scale. The decay can be described by solving the heat transfer equations including both the bulk conductivity in water and a finite thermal boundary resistance at the particle-water interface. The lattice expansion rises linearly with excitation power, up to an excitation power corresponding to a lattice temperature increase of 529 K. At higher temperatures the lattice shows a loss of long-range order due to pre-melting of the particles. At the bulk melting temperature, complete melting occurs within the first 100 ps after laser excitation.
TL;DR: The authors' studies indicate that in diabetes the synthetic enzymes of the two major endogenous vasodilators undergo oxidative inactivation by different mechanisms, which are, however, tightly interdependent.
Abstract: Macro and microvascular diseases are the principal causes of morbidity and mortality in patients with type I and II diabetes mellitus. Growing evidence implicates reactive nitrogen species (RNS), s...
TL;DR: It is reported that inactivation of the p66shc gene protects against age-dependent, ROS-mediated endothelial dysfunction and may represent a novel target to prevent vascular aging.
Abstract: Background— Enhanced production of reactive oxygen species (ROS) has been recognized as the major determinant of age-related endothelial dysfunction. The p66shc protein controls cellular responses to oxidative stress. Mice lacking p66shc (p66shc−/−) have increased resistance to ROS and a 30% prolonged life span. The present study investigates age-dependent changes of endothelial function in this model. Methods and Results— Aortic rings from young and old p66shc−/− or wild-type (WT) mice were suspended for isometric tension recording. Nitric oxide (NO) release was measured by a porphyrinic microsensor. Expression of endothelial NO synthase (eNOS), inducible NOS (iNOS), superoxide dismutase, and nitrotyrosine-containing proteins was assessed by Western blotting. Nitrotyrosine residues were also identified by immunohistochemistry. Superoxide (O2−) production was determined by coelenterazine-enhanced chemiluminescence. Endothelium-dependent relaxation in response to acetylcholine was age-dependently impaired ...
TL;DR: The results suggest that affectively arousing information is selected preferentially from a temporal stream, facilitating processes such as working memory consolidation and action.
Abstract: The present study aimed to examine affective modulation of the "attentional blink" effect during rapid serial visual presentation (RSVP). Pleasant, neutral, and unpleasant written verbs were used as a 2nd target (T2) in an 8.6-Hz RSVP paradigm. Pronounced effects of 1st target (T1)-T2 stimulus onset asynchrony (SOA) were found, showing reduced report accuracy for 232- and 464-ms SOAs. Affectively arousing (pleasant and unpleasant) T2s were associated with enhanced accuracy compared with neutral T2s specifically during short (232 ms) SOAs. In contrast, pleasant and unpleasant T2s rated low in terms of emotional arousal did not show this enhancement. These results suggest that affectively arousing information is selected preferentially from a temporal stream, facilitating processes such as working memory consolidation and action.
TL;DR: B cells in autoimmune disorders contain a so far uncharacterized subpopulation with an activated phenotype (CD19hiCD21loCD38loCD86int).
TL;DR: It is indicated that the ability to oxidize ferrous iron with nitrate is widespread amongst the Proteobacteria and may also be found among the Gram-positive bacteria with high GC content of DNA.
Abstract: In previous studies, three different strains (BrG1, BrG2, and BrG3) of ferrous iron-oxidizing, nitrate-reducing bacteria were obtained from freshwater sediments. All three strains were facultative anaerobes and utilized a variety of organic substrates and molecular hydrogen with nitrate as electron acceptor. In this study, analyses of 16S rDNA sequences showed that strain BrG1 was affiliated with the genus Acidovorax, strain BrG2 with the genus Aquabacterium, and strain BrG3 with the genus Thermomonas. Previously, bacteria similar to these three strains were detected with molecular techniques in MPN dilution series for ferrous iron-oxidizing, nitrate-reducing bacteria inoculated with different freshwater sediment samples. In the present study, further molecular analyses of these MPN cultures indicated that the ability to oxidize ferrous iron with nitrate is widespread amongst the Proteobacteria and may also be found among the Gram-positive bacteria with high GC content of DNA. Nitrate-reducing bacteria ox...
TL;DR: It is shown that reggie-1 is myristoylated and multiply palmitoylation and that lipid modifications are necessary for membrane association of reggie -1, suggesting a role for reggies-1 as a signalling protein in actin-dependent processes.
Abstract: The reggie protein family consists of two proteins, reggie-1 and -2, also called flotillins, which are highly ubiquitous and evolutionarily conserved. Both reggies have been shown to be associated with membrane rafts and are involved in various cellular processes such as T-cell activation, phagocytosis and insulin signalling. However, the exact molecular function of these proteins remains to be determined. In addition, the mechanism of membrane association of reggie-1, which does not contain any transmembrane domain, is not known. In this study, we have produced a fusion protein of reggie-1 with enhanced green fluorescent protein and generated targeted substitutions for the inactivation of putative palmitoylation and myristoylation sites. We were able to show that reggie-1 is myristoylated and multiply palmitoylated and that lipid modifications are necessary for membrane association of reggie-1. Overexpression of reggie-1 resulted in the induction of numerous filopodia-like protrusions in various cell lines, suggesting a role for reggie-1 as a signalling protein in actin-dependent processes.
TL;DR: In this article, the authors analyse institutions of governance in four cross-border regions in Europe and North America, and find that the transition from "spaces of place" to "space of flows" is a process characterized by an "unbundling" of identities and jurisdictions.
Abstract: To what extent are we experiencing a transformation from ‘spaces of place’ to a ‘space of flows’ as proposed by Manuel Castells? Applying his thesis to the political system leads to the following implications. Socio-economic processes of ‘glocalization’ are undermining the gate-keeper position of national governments. Furthermore, governance is becoming ‘deterritorialized’, an aspect which is characterized by Elkins as an ‘unbundling’ of identities and jurisdictions. But does this process of unbundling lead to a federal system of multi-level governance where the national level is complemented by supranational and subnational levels of governance; or does it imply an even more radical transformation towards an architecture of governance which is characterized by a proliferation of single-purpose governments with variable and flexible spatial scales? A final implication is the transformation from ‘government to governance’— which means a broader array of actors and changing modes of interaction. This article traces these theses by analysing institutions of governance in four cross-border regions in Europe and North America. In all regions we indeed find many cross-border networks and institutions undermining the national gate-keeper position. In Europe, cross-border collaboration is producing another soft, but institutionalized, comprehensive, stable and territorially-defined layer in the European ‘multi-level-system’. In North America, by contrast, only informal, fluid, specific and non-territorial institutions are evolving across national borders. Here, the territorially-based nation state is not complemented by similar kinds of political institutions, but is instead being challenged more fundamentally by new kinds of institutions: transnational socio-economic exchange networks and transnational ideological coalitions which embody enormous transformational power. In conclusion, cross-border regional governance in Europe still follows the logic of ‘spaces of place’, whereas in North America quite different ‘spaces of flows’ are emerging as complementary logics of community and institution building.
Jusqu'ou s'exerce la transformation d'un ‘espace de lieux’ en ‘espace des flux’, comme le suggere Manuel Castells? L'application de cette theorie au systeme politique a plusieurs implications. Les processus socio-economiques de ‘glocalisation’ desagregent la position de garde-barriere des gouvernements nationaux. De plus, la gouvernance se ‘deterritorialise’, phenomene qu'Elkins appelle la ‘separation’ des identites et des domaines de competence. Mais a quel type de gouvernance cette ‘separation’ mene-t-elle: a un systeme federal a plusieurs niveaux ou le plan national est complete de plans supra- et infra-nationaux de gouvernance? ou a un changement plus radical vers une architecture caracterisee par une proliferation de gouvernements a finalite unique dont les echelles spatiales varient et s'adaptent? Une derniere consequence est le passage de gouvernement a gouvernance, qui se traduit par une diversification des acteurs et de nouveaux modes d'interactions. L'article retrouve ces theses en analysant des institutions de gouvernance dans quatre regions transfrontalieres europeennes et nord-americaines. Dans toutes les regions, l'etude identifie en effet de nombreux reseaux et institutions transfrontaliers qui minent la position de garde-barriere nationale. En Europe, la collaboration transfrontaliere cree une strate souple, quoique institutionnalisee, etendue, stable et aux limites territoriales definies dans le ‘systeme europeen a plusieurs niveaux’. En Amerique du Nord, en revanche, n'interviennent a travers les frontieres que des institutions informelles, fluides, specifiques et non-territoriales; l'Etat-nation lie au territoire n'est pas complete d'institutions politiques de types similaires, etant plutot profondement mis en cause par des institutions d'un genre nouveau: reseaux d'echanges socio-economiques et coalitions ideologiques transnationaux qui expriment une enorme dynamique de transformation. Pour conclure, la gouvernance regionale transfrontaliere en Europe obeit encore a la logique des ‘espaces de lieux’ tandis qu'en Amerique du Nord, des ‘espaces de flux’ tout a fait differents apparaissent dans une logique complementaire de construction de communautes et d'institutions.
TL;DR: In this paper, the influence of different salt ions or polymer molecules on the size and distribution of the final titania particles was investigated, and electron microscopy, thermogravimetry, 1H-MAS NMR, X-ray absorption spectroscopy, and electrophoresis.
Abstract: Monodisperse spherical titania particles of variable sizes are produced in a sol−gel synthesis from Ti(EtO)4 in ethanol with addition of a salt or a polymer solution. The influence of different salt ions or polymer molecules on the size and the size distribution of the final particles was investigated. The amorphous hydrous titania particles were characterized by electron microscopy, thermogravimetry, 1H-MAS NMR, X-ray absorption spectroscopy, and electrophoresis. Nitrogen absorption measurements revealed that the addition of polymers yields hollow and porous titania colloids.
TL;DR: Recent molecular data on population differentiation and phylogenetics are reviewed, which have helped to unravel, to some extent, the patterns and processes that led to the formation and ecological maintenance of cichlid species flocks.
Abstract: With more than 3,000 species, the fish fami- ly Cichlidae is one of the most species-rich families of vertebrates. Cichlids occur in southern and central Amer- ica, Africa, Madagascar, and India. The hotspot of their biodiversity is East Africa, where they form adaptive ra- diations composed of hundreds of endemic species in several lakes of various sizes and ages. The unparalleled species richness of East African cichlids has been some- thing of a conundrum for evolutionary biologists and ecologists, since it has been in doubt whether these hun- dreds of species arose by allopatric speciation or whether it is necessary to invoke somewhat less traditional models of speciation, such as micro-allopatric, peripatric, or even sympatric speciation or evolution through sexual selection mediated by female choice. Ernst Mayr's analyses of these evolutionary uniquely diverse species assemblages have contributed to a more direct approach to this prob- lem and have led to a deeper understanding of the patterns and processes that caused the formation of these huge groups of species. We review here recent molecular data on population differentiation and phylogenetics, which have helped to unravel, to some extent, the patterns and processes that led to the formation and ecological main- tenance of cichlid species flocks. It is becoming apparent that sexually selected traits do play an important role in speciation in micro-allopatric or even sympatric settings. Species richness seems to be roughly correlated with the surface area, but not the age, of the lakes. We observe that the oldest lineages of a species flock of cichlids are often less species-rich and live in the open water or deepwater habitats. While the species flocks of the Lake Malawai and the Lake Victoria areas were shown to be mono- phyletic, the cichlid assemblage of Lake Tanganyika seems to consist of several independent species flocks. Cichlids emerge as an evolutionary model system in which many fundamental questions in evolution and ecology can be tested successfully, yet for other fish species flocks the relative importance of alternative mechanisms of speciation is likely to differ from that in cichlid fish.
TL;DR: Optical video microscopy study shows evidence that the particle self-diffusion is non-Fickian for long periods of time, and the distribution of particle displacement is a Gaussian function.
Abstract: We study the diffusive behavior of colloidal particles which are confined to one-dimensional channels generated by scanning optical tweezers. At long times t, the mean-square displacement is found to scale as t(1/2), which is expected for systems where single-file diffusion occurs. In addition, we experimentally obtain the long-time, self-diffusive behavior from the short-time collective density fluctuations of the system as suggested by a recent analytical approach [Phys. Rev. Lett. 90, 180602 (2003)].
TL;DR: A series of 1,5-dialkyl-1,2,4-triazole derivatives of acetic acid alkylidene hydrazides, evaluated in a series of human cancer cell in cultures and none have shown activity except 25 which exhibited remarkable activity against nine cancer types.
Abstract: A series of 1,5-dialkyl-1,2,4-triazole derivatives of acetic acid alkylidene hydrazides 8-12, the acid 13, 1,5-dialkyl-3-(5-mercapto-4-N-aryl-1H-[1,2,4]-triazol-3-ylmethylene)-1H-[1,2,4] triazoles 14-16, their 1,3,4-oxadiazole analogues 17-21, as well as the 1,2,4-triazolo-indoles 25 and 27 were prepared. The Z/E conformations of some acetic acid alkylidene derivatives were studied by NMR spectroscopy. Most of the target compounds were evaluated in a series of human cancer cell in cultures and none have shown activity except 25 which exhibited remarkable activity against nine cancer types. No in vitro antiviral activity against HIV-1, HIV-2, HSV-1, HSV-2, SV, CV-B4, RSV, P3V, RV, SinV, PTV has been found for all the synthesized compounds.
TL;DR: The authors outline the range of reorganization of human representational cortex, encompassing reconstruction in concurrence with enhanced behaviorally relevant afferent activity; injury-related response dynamics as, for instance, driven by loss of input; and maladaptive reorganization pushed by the interaction between neuroplastic processes and aberrant environmental requirements.
Abstract: Animal and human research over the past decades have increasingly detailed the brain's capacity for reorganization of neural network architecture to adapt to environmental needs. In this article, the authors outline the range of reorganization of human representational cortex, encompassing 1) reconstruction in concurrence with enhanced behaviorally relevant afferent activity (examples include skilled musicians and blind Braille readers); 2) injury-related response dynamics as, for instance, driven by loss of input (examples include stroke, amputation, or in blind individuals); and 3) maladaptive reorganization pushed by the interaction between neuroplastic processes and aberrant environmental requirements (examples include synchronicity of input nurturing focal hand dystonia). These types of neuroplasticity have consequences for both understanding pathological dynamics and therapeutic options. This will be illustrated in examples of motor and language rehabilitation after stroke, the treatment of focal hand dystonia, and concomitants of injury-related reorganization such as phantom limb pain.