189 research outputs found

    Pan-African displaced terranes in the Tuareg shield (central Sahara)

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    The time of the Roma in times of crisis: Where has European neoliberal capitalism failed?

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    This paper argues that the economic and financial crisis that has ensnared Europe from the late 2000s has been instrumental in reshaping employment and social relations in a detrimental way for the majority of the European people. It argues that the crisis has exacerbated the socio-economic position of most Roma people, immigrants as well as of other vulnerable groups. This development is approached here as an outcome of the widening structural inequalities that underpin the crisis within an increasingly neoliberalised Europe. Through recent policy developments and public discourses from a number of European countries I show how rising inequalities nurture racialised social tensions. My account draws on classic and contemporary theoretical propositions that have been propounded about the nature of capitalism, its contemporary re-articulation as well as its ramification for the future of Europe

    Europe’s perennial "outsiders": a processual approach to Roma stigmatization and ghettoization

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    This paper draws on the theoretical work of Norbert Elias and Loïc Wacquant in seeking to understand the stigmatized and marginalized position of the Roma population within Europe. The paper argues that the persistent persecution of Roma, reflected in social policy, cannot be understood without reference to long-term social processes, which shape the nature of the asymmetric power relations between Roma and non-Roma. Elias's theory of established-outsider relations is applied at the intra-state European level in arguing that Roma constitute a cross-border "outsider" group; with their intense stigmatization explained and perpetuated by a common set of collective fantasies which are maintained through complex group processes of disidentification, and which result in Roma being seen as of lesser human worth. Wacquant's theoretical concept of the "ghetto" is then drawn upon to show how the manifestations of stigmatization for the stigmatized are at once psychological, social and spatial. The paper suggests that the synthesis of the two theorists' relational, theoretical concepts allows for an approach that can expose the way in which power is exercised within and through group relations. Such an approach emphasizes the centrality of the interdependence between Roma and non-Roma, and the fluctuating power balance that characterises that relationship across time and space. The paper concludes that, while existing research focused on policy and outcomes is useful in understanding the negative contemporary experiences of Roma populations, they need to be understood in the context of wider social processes and historical continuities in seeking to elucidate how these processes shape policies and contribute to social and spatial marginalization

    Analysis of SEC9 Suppression Reveals a Relationship of SNARE Function to Cell Physiology

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    BACKGROUND:Growth and division of Saccharomyces cerevisiae is dependent on the action of SNARE proteins that are required for membrane fusion. SNAREs are regulated, through a poorly understood mechanism, to ensure membrane fusion at the correct time and place within a cell. Although fusion of secretory vesicles with the plasma membrane is important for yeast cell growth, the relationship between exocytic SNAREs and cell physiology has not been established. METHODOLOGY/PRINCIPAL FINDINGS:Using genetic analysis, we identified several influences on the function of exocytic SNAREs. Genetic disruption of the V-ATPase, but not vacuolar proteolysis, can suppress two different temperature-sensitive mutations in SEC9. Suppression is unlikely due to increased SNARE complex formation because increasing SNARE complex formation, through overexpression of SRO7, does not result in suppression. We also observed suppression of sec9 mutations by growth on alkaline media or on a non-fermentable carbon source, conditions associated with a reduced growth rate of wild-type cells and decreased SNARE complex formation. CONCLUSIONS/SIGNIFICANCE:Three main conclusions arise from our results. First, there is a genetic interaction between SEC9 and the V-ATPase, although it is unlikely that this interaction has functional significance with respect to membrane fusion or SNAREs. Second, Sro7p acts to promote SNARE complex formation. Finally, Sec9p function and SNARE complex formation are tightly coupled to the physiological state of the cell

    Sensitivity of the human auditory cortex to acoustic degradation of speech and non-speech sounds

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    The perception of speech is usually an effortless and reliable process even in highly adverse listening conditions. In addition to external sound sources, the intelligibility of speech can be reduced by degradation of the structure of speech signal itself, for example by digital compression of sound. This kind of distortion may be even more detrimental to speech intelligibility than external distortion, given that the auditory system will not be able to utilize sound source-specific acoustic features, such as spatial location, to separate the distortion from the speech signal. The perceptual consequences of acoustic distortions on speech intelligibility have been extensively studied. However, the cortical mechanisms of speech perception in adverse listening conditions are not well known at present, particularly in situations where the speech signal itself is distorted. The aim of this thesis was to investigate the cortical mechanisms underlying speech perception in conditions where speech is less intelligible due to external distortion or as a result of digital compression. In the studies of this thesis, the intelligibility of speech was varied either by digital compression or addition of stochastic noise. Cortical activity related to the speech stimuli was measured using magnetoencephalography (MEG). The results indicated that degradation of speech sounds by digital compression enhanced the evoked responses originating from the auditory cortex, whereas addition of stochastic noise did not modulate the cortical responses. Furthermore, it was shown that if the distortion was presented continuously in the background, the transient activity of auditory cortex was delayed. On the perceptual level, digital compression reduced the comprehensibility of speech more than additive stochastic noise. In addition, it was also demonstrated that prior knowledge of speech content enhanced the intelligibility of distorted speech substantially, and this perceptual change was associated with an increase in cortical activity within several regions adjacent to auditory cortex. In conclusion, the results of this thesis show that the auditory cortex is very sensitive to the acoustic features of the distortion, while at later processing stages, several cortical areas reflect the intelligibility of speech. These findings suggest that the auditory system rapidly adapts to the variability of the auditory environment, and can efficiently utilize previous knowledge of speech content in deciphering acoustically degraded speech signals.Puheen havaitseminen on useimmiten vaivatonta ja luotettavaa myös erittäin huonoissa kuunteluolosuhteissa. Puheen ymmärrettävyys voi kuitenkin heikentyä ympäristön häiriölähteiden lisäksi myös silloin, kun puhesignaalin rakennetta muutetaan esimerkiksi pakkaamalla digitaalista ääntä. Tällainen häiriö voi heikentää ymmärrettävyyttä jopa ulkoisia häiriöitä voimakkaammin, koska kuulojärjestelmä ei pysty hyödyntämään äänilähteen ominaisuuksia, kuten äänen tulosuuntaa, häiriön erottelemisessa puheesta. Akustisten häiriöiden vaikutuksia puheen havaitsemiseen on tutkttu laajalti, mutta havaitsemiseen liittyvät aivomekanismit tunnetaan edelleen melko puutteelisesti etenkin tilanteissa, joissa itse puhesignaali on laadultaan heikentynyt. Tämän väitöskirjan tavoitteena oli tutkia puheen havaitsemisen aivomekanismeja tilanteissa, joissa puhesignaali on vaikeammin ymmärrettävissä joko ulkoisen äänilähteen tai digitaalisen pakkauksen vuoksi. Väitöskirjan neljässä osatutkimuksessa lyhyiden puheäänien ja jatkuvan puheen ymmärrettävyyttä muokattiin joko digitaalisen pakkauksen kautta tai lisäämällä puhesignaaliin satunnaiskohinaa. Puheärsykkeisiin liittyvää aivotoimintaa tutkittiin magnetoenkefalografia-mittauksilla. Tutkimuksissa havaittiin, että kuuloaivokuorella syntyneet herätevasteet voimistuivat, kun puheääntä pakattiin digitaalisesti. Sen sijaan puheääniin lisätty satunnaiskohina ei vaikuttanut herätevasteisiin. Edelleen, mikäli puheäänien taustalla esitettiin jatkuvaa häiriötä, kuuloaivokuoren aktivoituminen viivästyi häiriön intensiteetin kasvaessa. Kuuntelukokeissa havaittiin, että digitaalinen pakkaus heikentää puheäänien ymmärrettävyyttä voimakkaammin kuin satunnaiskohina. Lisäksi osoitettiin, että aiempi tieto puheen sisällöstä paransi merkittävästi häiriöisen puheen ymmärrettävyyttä, mikä heijastui aivotoimintaan kuuloaivokuoren viereisillä aivoalueilla siten, että ymmärrettävä puhe aiheutti suuremman aktivaation kuin heikosti ymmärrettävä puhe. Väitöskirjan tulokset osoittavat, että kuuloaivokuori on erittäin herkkä puheäänien akustisille häiriöille, ja myöhemmissä prosessoinnin vaiheissa useat kuuloaivokuoren viereiset aivoalueet heijastavat puheen ymmärrettävyyttä. Tulosten mukaan voi olettaa, että kuulojärjestelmä mukautuu nopeasti ääniympäristön vaihteluihin muun muassa hyödyntämällä aiempaa tietoa puheen sisällöstä tulkitessaan häiriöistä puhesignaalia

    The evolution of language: a comparative review

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    For many years the evolution of language has been seen as a disreputable topic, mired in fanciful "just so stories" about language origins. However, in the last decade a new synthesis of modern linguistics, cognitive neuroscience and neo-Darwinian evolutionary theory has begun to make important contributions to our understanding of the biology and evolution of language. I review some of this recent progress, focusing on the value of the comparative method, which uses data from animal species to draw inferences about language evolution. Discussing speech first, I show how data concerning a wide variety of species, from monkeys to birds, can increase our understanding of the anatomical and neural mechanisms underlying human spoken language, and how bird and whale song provide insights into the ultimate evolutionary function of language. I discuss the ‘‘descended larynx’ ’ of humans, a peculiar adaptation for speech that has received much attention in the past, which despite earlier claims is not uniquely human. Then I will turn to the neural mechanisms underlying spoken language, pointing out the difficulties animals apparently experience in perceiving hierarchical structure in sounds, and stressing the importance of vocal imitation in the evolution of a spoken language. Turning to ultimate function, I suggest that communication among kin (especially between parents and offspring) played a crucial but neglected role in driving language evolution. Finally, I briefly discuss phylogeny, discussing hypotheses that offer plausible routes to human language from a non-linguistic chimp-like ancestor. I conclude that comparative data from living animals will be key to developing a richer, more interdisciplinary understanding of our most distinctively human trait: language

    Ancient, independent evolution and distinct molecular features of the novel human T-lymphotropic virus type 4

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    <p>Abstract</p> <p>Background</p> <p>Human T-lymphotropic virus type 4 (HTLV-4) is a new deltaretrovirus recently identified in a primate hunter in Cameroon. Limited sequence analysis previously showed that HTLV-4 may be distinct from HTLV-1, HTLV-2, and HTLV-3, and their simian counterparts, STLV-1, STLV-2, and STLV-3, respectively. Analysis of full-length genomes can provide basic information on the evolutionary history and replication and pathogenic potential of new viruses.</p> <p>Results</p> <p>We report here the first complete HTLV-4 sequence obtained by PCR-based genome walking using uncultured peripheral blood lymphocyte DNA from an HTLV-4-infected person. The HTLV-4(1863LE) genome is 8791-bp long and is equidistant from HTLV-1, HTLV-2, and HTLV-3 sharing only 62–71% nucleotide identity. HTLV-4 has a prototypic genomic structure with all enzymatic, regulatory, and structural proteins preserved. Like STLV-2, STLV-3, and HTLV-3, HTLV-4 is missing a third 21-bp transcription element found in the long terminal repeats of HTLV-1 and HTLV-2 but instead contains unique c-Myb and pre B-cell leukemic transcription factor binding sites. Like HTLV-2, the PDZ motif important for cellular signal transduction and transformation in HTLV-1 and HTLV-3 is missing in the C-terminus of the HTLV-4 Tax protein. A basic leucine zipper (b-ZIP) region located in the antisense strand of HTLV-1 and believed to play a role in viral replication and oncogenesis, was also found in the complementary strand of HTLV-4. Detailed phylogenetic analysis shows that HTLV-4 is clearly a monophyletic viral group. Dating using a relaxed molecular clock inferred that the most recent common ancestor of HTLV-4 and HTLV-2/STLV-2 occurred 49,800 to 378,000 years ago making this the oldest known PTLV lineage. Interestingly, this period coincides with the emergence of <it>Homo sapiens sapiens </it>during the Middle Pleistocene suggesting that early humans may have been susceptible hosts for the ancestral HTLV-4.</p> <p>Conclusion</p> <p>The inferred ancient origin of HTLV-4 coinciding with the appearance of <it>Homo sapiens</it>, the propensity of STLVs to cross-species into humans, the fact that HTLV-1 and -2 spread globally following migrations of ancient populations, all suggest that HTLV-4 may be prevalent. Expanded surveillance and clinical studies are needed to better define the epidemiology and public health importance of HTLV-4 infection.</p
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