973 resultados para VASE-SHAPED MICROFOSSILS


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“Decidida a viure al preu que sigui” underscores contemporary writer Maria-Antònia Oliver in her prologue to Aurora Bertrana’s fourth book, El Marroc sensual i fanàtic (1936). The urge to travel, to explore the world and to slake her thirst for new experiences shaped much of the personality and the work of this Girona-born writer. Taking her own travels as a starting point, Bertrana distinguished herself in the genre of travel writing on exotic countries, which at that time underwent a significant revival in Catalonia. Bertrana’s originality lies partly in the image of the woman traveller that she consciously cultivated for herself, and partly in the way she narrates her travels. This article seeks to recover this author and make visible her singular way of presenting otherness.

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Tutkielman tavoitteena oli lähestyä Kiinan markkinoita suomalaisten pienten ja keskisuurten yritysten (pk-yritys) näkökulmasta. Tutkielman päätavoitteena oli käydä läpi niitä tekijöitä, joiden tiedostaminen auttaa suomalaisia pk-yrityksiä etabloitumaan Kiinan markkinoille. Tutkielman tarkoituksena oli myös tuottaa oleellista yleistietoa Kiinasta liiketoimintaympäristönä, minkä etsiminen on usein hyvin aikaakuluttavaa. Yleistiedon pohjalta pk-yritykset voivat punnita soveltuuko uusi ja houkutteleva markkina-alue niille. Tutkielma on luonteeltaan lähinnä kuvaileva markkinatutkimus, joka perustuu jo olemassa olevaan tietoon Kiinan markkinoista. Tutkielma toteutettiin ns. kirjoituspöytätutkimuksena ja suurin osa tiedosta on sekundaarista, yleistietoa liiketoimintaympäristöstä. Tutkielman lähdeaineistona käytettiin mahdollisimman uutta koti- ja ulkomaista kirjallisuutta, artikkeleita sekä seminaareissa esitettyjä tutkimuspapereita. Lähdeaineiston käsittely perustui aineistolähtöiseen analyysiin. Analyysin avulla pyrittiin tiivistämään aineisto ja kasvattamaan sen informaatioarvoa luomalla hajanaisesta aineistosta selkeää ja mielekästä, kadottamatta silti sen sisältämää informaatiota. Tässä tutkielmassa esiin tulleiden tekijöiden perusteella vaikuttaa siltä, että suomalaisilla pk-yrityksillä on huomattavia kehitys- ja kasvumahdollisuuksia Kiinan markkinoilla. Parhaat mahdollisuudet menestyä Kiinan markkinoilla on niillä yrityksillä, jotka omaavat kansainvälistä kokemusta, ovat teknologiaorientoituneita ja pitkälle erikoistuneita omalla toimialallaan. Menestyminen edellyttää myös hyvää paikallista markkinatuntemusta, kykyä solmia hyviä kontakteja paikallisiin viranomaisiin ja markkinoilla toimijoihin sekä valmiutta sitoutua pitkällä aikajänteellä Kiinan markkinoille.

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Anthropomorphic model observers are mathe- matical algorithms which are applied to images with the ultimate goal of predicting human signal detection and classification accuracy across varieties of backgrounds, image acquisitions and display conditions. A limitation of current channelized model observers is their inability to handle irregularly-shaped signals, which are common in clinical images, without a high number of directional channels. Here, we derive a new linear model observer based on convolution channels which we refer to as the "Filtered Channel observer" (FCO), as an extension of the channelized Hotelling observer (CHO) and the nonprewhitening with an eye filter (NPWE) observer. In analogy to the CHO, this linear model observer can take the form of a single template with an external noise term. To compare with human observers, we tested signals with irregular and asymmetrical shapes spanning the size of lesions down to those of microcalfications in 4-AFC breast tomosynthesis detection tasks, with three different contrasts for each case. Whereas humans uniformly outperformed conventional CHOs, the FCO observer outperformed humans for every signal with only one exception. Additive internal noise in the models allowed us to degrade model performance and match human performance. We could not match all the human performances with a model with a single internal noise component for all signal shape, size and contrast conditions. This suggests that either the internal noise might vary across signals or that the model cannot entirely capture the human detection strategy. However, the FCO model offers an efficient way to apprehend human observer performance for a non-symmetric signal.

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Laboratory and field experiments have demonstrated in many cases that malaria vectors do not feed randomly, but show important preferences either for infected or non-infected hosts. These preferences are likely in part shaped by the costs imposed by the parasites on both their vertebrate and dipteran hosts. However, the effect of changes in vector behaviour on actual parasite transmission remains a debated issue. We used the natural associations between a malaria-like parasite Polychromophilus murinus, the bat fly Nycteribia kolenatii and a vertebrate host the Daubenton's bat Myotis daubentonii to test the vector's feeding preference based on the host's infection status using two different approaches: 1) controlled behavioural assays in the laboratory where bat flies could choose between a pair of hosts; 2) natural bat fly abundance data from wild-caught bats, serving as an approximation of realised feeding preference of the bat flies. Hosts with the fewest infectious stages of the parasite were most attractive to the bat flies that did switch in the behavioural assay. In line with the hypothesis of costs imposed by parasites on their vectors, bat flies carrying parasites had higher mortality. However, in wild populations, bat flies were found feeding more based on the bat's body condition, rather than its infection level. Though the absolute frequency of host switches performed by the bat flies during the assays was low, in the context of potential parasite transmission they were extremely high. The decreased survival of infected bat flies suggests that the preference for less infected hosts is an adaptive trait. Nonetheless, other ecological processes ultimately determine the vector's biting rate and thus transmission. Inherent vector preferences therefore play only a marginal role in parasite transmission in the field. The ecological processes rather than preferences per se need to be identified for successful epidemiological predictions.

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Monikulttuurinen johtaminen on globalisaation ja nopean kansainvälistymisen takia erittäin ajankohtainen aihe. Suomessa sitä on kuitenkin tutkittu vasta vähän. Tämän tutkimuksen tarkoituksena on tutkia Suomen suurlähetystöjenmonikulttuurista johtamista Aasian eri kohdemaissa ja kulttuureissa sekä ottaa osaa tieteelliseen keskusteluun monikulttuurisesta johtamisesta. Tutkimuksen kohdemaiksi on valittu neljä Aasian maata, jotka ovat tällä hetkellä hyvin ajankohtaisia nopean talouskasvunsa takia. Itä-Aasiasta mukana ovat Etelä-Korea (Korean tasavalta), Japani ja Kiinan kansantasavalta sekä Kaakkois-Aasiasta tutkimuksessa mukana on Malesia. Tämä tutkimus on laadullinen tutkimus, jonka aineisto koostuu kahdesta laadulliselle tutkimukselle poikkeuksellisesta avoimesta kyselystä, jotka on lähetetty edellä mainittujen maiden suurlähettiläille eri kohdemaihin. Analyysissä menetelmänä on käytetty teemoittelua, jonka avulla on voitu jäsentää saatua aineistoa. Näin teemojen vertailu on myös ollut helpompaa. Tutkimuksen tuloksista kävi ilmi, että monikulttuurinen johtaminen on erittäin haasteellista kansallisten kulttuurien eroista johtuen. Arvot ovat hyvin keskeisessä osassa kulttuuria tutkittaessa ja niiden erot voivat vaikeuttaa kanssakäymistä eri kulttuureista tulevien ihmisten kesken, koska asioiden merkitykset jäävät usein arvoituksiksi vieraasta kulttuurista tuleville henkilöille. Kansallisen kulttuurin tekijöistä kieli, arvot ja uskonto ovat merkittäviä monikulttuurisen johtamisen kannalta. Tutkimuksesta kävi myös ilmi, että Itä- Aasian maissa konfutselaisuudella on suuri merkitys yhteiskuntafilosofiana. Se on muokannut yhteiskunnan arvoja, tapoja ja rakenteita. Vanhempien ja ylempiarvoisten ihmisten arvostus ja vahvasti hierarkkinen yhteiskuntarakenne ovat tyypillisiä konfutselaisuuden piirteitä. Kulttuurin ulottuvuuksista merkityksellisempiä tämän tutkimuksen kannalta ovat yksilöllisyys vs. kollektiivisuus, valtaetäisyys ja konfutselaisuuden dynamiikka (lyhyen vs. pitkän aikavälin suuntautuminen). Kaikki tämän tutkimuksen maat ovat kollektiivisia sekä niissä valtaetäisyys on myös korkea. Tämä tuo haasteita monikulttuuriseen johtamiseen Suomen suurlähetystöissä, koska suomalainen kulttuuri on useimpien länsimaiden tapaan yksilöllinen ja valtaetäisyys on suhteellisen matala. Konfutselaisuuden dynamiikka vaikuttaa lähinnä vain Itä-Aasian maissa tuoden mukanaan erittäin vahvan hierarkian, jota ei voi sivuuttaa. Tutkimuksen aineistoa käsitellään näytenäkökulmasta, eikä sitä ei voisuoraan verrata muihin organisaatioihin tai kulttuureihin. Toisaalta jokaisen kansallisen kulttuurin ihmiset toimivat tietyllä tavalla tietyssä kontekstissa, riippumatta siitä, missä organisaatiossa he työskentelevät. Kulttuuri ohjaa ihmisen toimintaa ja kansallinen kulttuuri on yrityskulttuuria voimakkaampi tekijä.

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Cells couple growth with division and regulate size in response to nutrient availability. In rod-shaped fission yeast, cell-size control occurs at mitotic commitment. An important regulator is the DYRK-family kinase Pom1, which forms gradients from cell poles and inhibits the mitotic activator Cdr2, itself localized at the medial cortex. Where and when Pom1 modulates Cdr2 activity is unclear as Pom1 medial cortical levels remain constant during cell elongation. Here we show that Pom1 re-localizes to cell sides upon environmental glucose limitation, where it strongly delays mitosis. This re-localization is caused by severe microtubule destabilization upon glucose starvation, with microtubules undergoing catastrophe and depositing the Pom1 gradient nucleator Tea4 at cell sides. Microtubule destabilization requires PKA/Pka1 activity, which negatively regulates the microtubule rescue factor CLASP/Cls1/Peg1, reducing CLASP's ability to stabilize microtubules. Thus, PKA signalling tunes CLASP's activity to promote Pom1 cell side localization and buffer cell size upon glucose starvation.

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Cells couple their growth and division rate in response to nutrient availability to maintain a constant size. This co-ordination happens either at the G1-S or the G2-M transition of the cell cycle. In the rod-shaped fission yeast, size regulation happens at the G2-M transition prior to mitotic commitment. Recent studies have focused on the role of the DYRK-family protein kinase Pom1, which forms gradients emanating from cell poles and inhibits the mitotic activator kinase Cdr2, present at the cell middle. Pom1 was proposed to inhibit Cdr2 until cells reached a critical size before division. However when and where Pom1 inhibits Cdr2 is not clear as medial Pom1 levels do not change during cell elongation. Here I show that Pom1 gradients are susceptible to environmental changes in glucose. Specifically, upon glucose limitation, Pom1 re-localizes from the poles to the cell sides where it delays mitosis through regulating Cdr2. This re-localization occurs due to microtubule de- stabilization and lateral catastrophes leading to transient deposition of the Pom1 gradient nucleator Tea4 along the cell cortex. As Tea4 localization to cell sides is sufficient to recruit Pom1, this explains the mechanism of Pom1 re-localization. Microtubule destabilization and consequently Tea4 and Pom1 spread depends on the activity of the cAMP-dependent Protein Kinase A (PKA/Pka1), as pka1 mutant cells have stable microtubules and retain polar Tea4 and Pom1 under limited glucose. PKA signaling negatively regulates the microtubule rescue factor CLASP/Cls1, thus reducing its ability to stabilize microtubules. Thus PKA signaling tunes CLASP activity to promote microtubule de-stabilization and Pom1 re-localization upon glucose limitation. I show that the side-localized Pom1 delays mitosis and balances the role of the mitosis promoting, mitogen-associated protein kinase (MAPK) protein Sty1. Thus Pom1 re-localization may serve to buffer cell size upon glucose limitation. -- Afin de maintenir une taille constante, les cellules régulent leur croissance ainsi que leur taux de division selon les nutriments disponibles dans le milieu. Dans la levure fissipare, cette régulation de la taille précède l'engagement mitotique et se fait à la transition entre les phases G2 à M du cycle cellulaire. Des études récentes se sont focalisées sur le rôle de la protéine Pom1, membre de la famille des DYRK kinase. Celle-ci forme un gradient provenant des pôles de la cellule et inhibe l'activateur mitotique Cdr2 présent au centre de la cellule. Le model propose que Pom1 inhibe Cdr2 jusqu'à atteindre une taille critique avant la division. Cependant quand et à quel endroit dans la cellulle Pom1 inhibe Cdr2 n'était pas clair car les niveaux médians de Pom1 ne changent pas au cours de la l'élongation des cellules. Dans cette étude, je montre que les gradients de Pom1 sont sensibles aux changements environnementaux du taux de glucose. Plus spécifiquement, en conditions limitantes de glucose, Pom1 se relocalise des pôles de la cellule pour se distribuer sur les côtés de celle-ci. Par conséquent, un délai d'entrée en mitose est observé dû à l'inhibition Cdr2 par Pom1. Cette délocalisation est due à la déstabilisation des microtubules qui va conduire à une déposition transitoire de Tea4, le nucléateur du gradient de Pom1, tout au long du cortex de la cellule. Comme la localisation de Tea4 sur les côtés de la cellule est suffisante pour recruter la protéine Pom1, ceci explique le mécanisme de relocalisation de celle-ci. La déstabilisation des microtubules et par conséquent la diffusion de Tea4 et Pom1 dépendent de l'activité de la protéine kinase A dépendante de l'AMP cyclique (PKA/Pka1). En absence de pka1, la stabilité des microtubules n'est pas affectée ce qui permet la rétention de Tea4 et Pom1 aux pôles de la cellule même en conditions limitantes de glucose. La signalisation via PKA régule négativement le facteur de sauvetage des microtubules CLASP/Cls1 et permet donc de réduire sa fonction de déstabilisation des microtubules. Ainsi la signalisation via PKA affine l'activité des CLASP pour promouvoir la déstabilisation des microtubules et la relocalisation de Pom1 en conditions limitantes de glucose. Je montre que la localisation sur les côtés retarde l'entrée en mitose et compense l'action de la protéine Sty1, connue pour être une MAPK qui induit l'entrée en mitose. Ainsi, la relocalisation de Pom1 pourrait servir à tamponner la taille de la cellule en condition limitantes de glucose. -- Various cell types in the environment such as bacterial, plant or animal cells have a distinct cellular size. Maintaining a constant cell size is important for fitness in unicellular organisms and for diverse functions in multicellular organisms. Cells regulate their size by coordinating their growth rate to their division rate. This coupling is important otherwise cells would get progressively smaller or larger after each successive cell cycle. In their natural environment cells may face fluctuations in the available nutrient supply. Thus cells have to coordinate their division rate to the variable growth rates shown under different nutrient conditions. During my PhD, I worked with a single-celled rod shaped yeast called the fission yeast. These cells are longer when the nutrient supply is abundant and shorter when the nutrient supply is scarce. A protein that senses changes in the external carbon source (glucose) is called Protein Kinase A (PKA). The rod shape of fission yeast cells is maintained thanks to a structural backbone called the cytoskeleton. One of the components of this backbone is called microtubules, which are small tube like structures spanning the length of the cell. They transport a protein called Tea4, which in turn is important for the proper localization of another protein Pom1 to the cell ends. Pom1 helps to maintain proper shape and size of these rod shaped yeast cells. My thesis work showed that upon reduction in the external nutrient (glucose) levels, microtubules become less stable and show an alteration in their organization. A significant percentage of the microtubules contact the side of the cell instead of touching only the cell tip. This leads to the spreading of the protein Pom1 away from the tips all around the cell periphery. This helps fission yeast cells to maintain the proper size required under these conditions of limited glucose supply. I further showed that the protein PKA regulates microtubule stability and organization and thus Pom1 spreading and maintenance of proper cell size. Thus my work led to the discovery of a novel pathway by which fission yeast cells maintain their size under limited supply of glucose. -- Divers types cellulaires dans l'environnement tels que les bactéries, les plantes ou les cellules animales ont une taille précise. Le maintien d'une taille cellulaire constante est importante pour le fitness des organismes unicellulaire ainsi que pour multiples fonctions dans les organismes multicellulaires. Les cellules régulent leur taille en coordonnant le taux de croissance avec le taux de division. Ce couplage est essentiel sinon les cellules deviendraient progressivement plus petites ou plus grandes après chaque cycle cellulaire. Dans leur habitat naturels les cellules peuvent faire face a des fluctuations dans le taux de nutriment disponible. Les cellules doivent donc coordonner leur taux de division aux taux variables de croissances perçus dans les différentes conditions nutritionnels. Pendant ma thèse, j'ai travaillée sur une levure unicellulaire, en forme de bâtonnet, nommé levure fissipare ou levure de fission. La taille de ces cellules est plus grande quand le taux de nutriments est grand et plus courte quand celui-ci est plus faible. Une protéine qui perçoit les changements dans le taux externe de la source de carbone (glucose) est nommée PKA pour protéine kinase A. La forme en bâtonnet de la cellule est due aux caractères structuraux du cytosquelette. Une composante importante de ce cytosquelette sont les microtubules, dont la structures ressemble à des petit tubes qui vont d'un bout à l'autre de la cellule. Ces microtubules transportent une protéine importante nommée Tea4 qui à leur tour importante pour la bonne localisation d'une autre protéine Pom1 aux extrémités de la cellule. La protéine Pom1 aide à maintenir la taille appropriée des levures fissipares. Mon travail de thèse a montré qu'en présence de taux faible de nutriments (glucose) les microtubules deviennent de moins en moins stables et montrent une désorganisation globale. Un pourcentage significatif des microtubules touche les côtés de la cellule aux lieu d'atteindre uniquement les extrémités. Ceci a pour conséquence une diffusion de Pom1 tout au long du cortex de la cellule. Ceci aide les levures fissipares à maintenir la taille appropriée pendant ce stress nutritionnel. De plus, je montre que PKA régule la stabilité et l'organisation des microtubules et par conséquent la diffusion de Pom1 et le maintien d'une taille constante. En conclusion, mon travail a conduit à la découverte d'un nouveau mécanisme par lequel la levure fissipare maintient sa taille dans des conditions limitantes en glucose.

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BACKGROUND: The structure and organisation of ecological interactions within an ecosystem is modified by the evolution and coevolution of the individual species it contains. Understanding how historical conditions have shaped this architecture is vital for understanding system responses to change at scales from the microbial upwards. However, in the absence of a group selection process, the collective behaviours and ecosystem functions exhibited by the whole community cannot be organised or adapted in a Darwinian sense. A long-standing open question thus persists: Are there alternative organising principles that enable us to understand and predict how the coevolution of the component species creates and maintains complex collective behaviours exhibited by the ecosystem as a whole? RESULTS: Here we answer this question by incorporating principles from connectionist learning, a previously unrelated discipline already using well-developed theories on how emergent behaviours arise in simple networks. Specifically, we show conditions where natural selection on ecological interactions is functionally equivalent to a simple type of connectionist learning, 'unsupervised learning', well-known in neural-network models of cognitive systems to produce many non-trivial collective behaviours. Accordingly, we find that a community can self-organise in a well-defined and non-trivial sense without selection at the community level; its organisation can be conditioned by past experience in the same sense as connectionist learning models habituate to stimuli. This conditioning drives the community to form a distributed ecological memory of multiple past states, causing the community to: a) converge to these states from any random initial composition; b) accurately restore historical compositions from small fragments; c) recover a state composition following disturbance; and d) to correctly classify ambiguous initial compositions according to their similarity to learned compositions. We examine how the formation of alternative stable states alters the community's response to changing environmental forcing, and we identify conditions under which the ecosystem exhibits hysteresis with potential for catastrophic regime shifts. CONCLUSIONS: This work highlights the potential of connectionist theory to expand our understanding of evo-eco dynamics and collective ecological behaviours. Within this framework we find that, despite not being a Darwinian unit, ecological communities can behave like connectionist learning systems, creating internal conditions that habituate to past environmental conditions and actively recalling those conditions. REVIEWERS: This article was reviewed by Prof. Ricard V Solé, Universitat Pompeu Fabra, Barcelona and Prof. Rob Knight, University of Colorado, Boulder.

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Division site positioning is critical for both symmetric and asymmetric cell divisions. In many organisms, positive and negative signals cooperate to position the contractile actin ring for cytokinesis. In rod-shaped fission yeast Schizosaccharomyces pombe cells, division at midcell is achieved through positive Mid1/anillin-dependent signaling emanating from the central nucleus and negative signals from the dual-specificity tyrosine phosphorylation-regulated kinase family kinase Pom1 at the cell poles. In this study, we show that Pom1 directly phosphorylates the F-BAR protein Cdc15, a central component of the cytokinetic ring. Pom1-dependent phosphorylation blocks Cdc15 binding to paxillin Pxl1 and C2 domain protein Fic1 and enhances Cdc15 dynamics. This promotes ring sliding from cell poles, which prevents septum assembly at the ends of cells with a displaced nucleus or lacking Mid1. Pom1 also slows down ring constriction. These results indicate that a strong negative signal from the Pom1 kinase at cell poles converts Cdc15 to its closed state, destabilizes the actomyosin ring, and thus promotes medial septation.

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The small intestine is a dynamic and complex organ that is characterized by constant epithelium turnover and crosstalk among various cell types and the microbiota. Lymphatic capillaries of the small intestine, called lacteals, play key roles in dietary fat absorption and the gut immune response; however, little is known about the molecular regulation of lacteal function. Here, we performed a high-resolution analysis of the small intestinal stroma and determined that lacteals reside in a permanent regenerative, proliferative state that is distinct from embryonic lymphangiogenesis or quiescent lymphatic vessels observed in other tissues. We further demonstrated that this continuous regeneration process is mediated by Notch signaling and that the expression of the Notch ligand delta-like 4 (DLL4) in lacteals requires activation of VEGFR3 and VEGFR2. Moreover, genetic inactivation of Dll4 in lymphatic endothelial cells led to lacteal regression and impaired dietary fat uptake. We propose that such a slow lymphatic regeneration mode is necessary to match a unique need of intestinal lymphatic vessels for both continuous maintenance, due to the constant exposure to dietary fat and mechanical strain, and efficient uptake of fat and immune cells. Our work reveals how lymphatic vessel responses are shaped by tissue specialization and uncover a role for continuous DLL4 signaling in the function of adult lymphatic vasculature.

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We present the results of stereoscopic observations of the satellite galaxy Segue 1 with the MAGIC Telescopes, carried out between 2011 and 2013. With almost 160 hours of good-quality data, this is the deepest observational campaign on any dwarf galaxy performed so far in the very high energy range of the electromagnetic spectrum. We search this large data sample for signals of dark matter particles in the mass range between 100 GeV and 20 TeV. For this we use the full likelihood analysis method, which provides optimal sensitivity to characteristic gamma-ray spectral features, like those expected from dark matter annihilation or decay. In particular, we focus our search on gamma-rays produced from different final state Standard Model particles, annihilation with internal bremsstrahlung, monochromatic lines and box-shaped signals. Our results represent the most stringent constraints to the annihilation cross-section or decay lifetime obtained from observations of satellite galaxies, for masses above few hundred GeV. In particular, our strongest limit (95% confidence level) corresponds to a ~ 500 GeV dark matter particle annihilating into τ+τ−, and is of order langleσannvrangle simeq 1.2 × 10−24 cm3 s−1 a factor ~ 40 above the langleσannvrangle simeq thermal value.

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High-frequency oscillations in the gamma-band reflect rhythmic synchronization of spike timing in active neural networks. The modulation of gamma oscillations is a widely established mechanism in a variety of neurobiological processes, yet its neurochemical basis is not fully understood. Modeling, in-vitro and in-vivo animal studies suggest that gamma oscillation properties depend on GABAergic inhibition. In humans, search for evidence linking total GABA concentration to gamma oscillations has led to promising -but also to partly diverging- observations. Here, we provide the first evidence of a direct relationship between the density of GABAA receptors and gamma oscillatory gamma responses in human primary visual cortex (V1). By combining Flumazenil-PET (to measure resting-levels of GABAA receptor density) and MEG (to measure visually-induced gamma oscillations), we found that GABAA receptor densities correlated positively with the frequency and negatively with amplitude of visually-induced gamma oscillations in V1. Our findings demonstrate that gamma-band response profiles of primary visual cortex across healthy individuals are shaped by GABAA-receptor-mediated inhibitory neurotransmission. These results bridge the gap with in-vitro and animal studies and may have future clinical implications given that altered GABAergic function, including dysregulation of GABAA receptors, has been related to psychiatric disorders including schizophrenia and depression.

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(ENGLISH VERSION BELOW) Dieser Beitrag fügt sich in eine post-doktorale Forschung über die Geschichte der Orthopädie ein, die unter dem Mandat des Centre Hospitalier Universitaire Vaudois (CHUV) geleitet wird und teilerweise auf die Archiv der Schweizerischen Gesellschaft für Orthopädie (aktuelle Swiss Orthopaedics) beruht. Die Autorin untersucht die Herausforderungen, welche die Geschichte der Orthopädie in der Schweiz prägten und berücksichtigt dabei die Anpassungsstrategien einer medizinischen und technischen Disziplin in einer sich wandelnden Gesellschaft. Zusammenfassung der Beitrag und Informationen auf der Website der Zeitschrift: http://econtent.hogrefe.com/toc/tum/72/7 This article is inspired by a post-doctorale research about the history of orthopedics, mandated by the Centre Hospitalier Universitaire Vaudois (CHUV), and partly supported by the Archiv of the Swiss Society of Orthopedics (nowadays Swiss Orthopaedics). By examining the implications that have shaped the history of orthopedics in Switzerland, the author seeks to shed light on the strategies that were implemented in adopting a medical and technical discipline within a transforming society. Summary of the article and information on the journal's website: http://econtent.hogrefe.com/toc/tum/72/7

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Cette recherche porte sur les roms (vlach) qui séjournent périodiquement en Suisse italienne, en camping-cars ou en caravanes, pratiquant un semi- nomadisme lié à des motivations principalement économiques, mais également familiales et religieuses. Elle poursuit simultanément deux objectifs. Le premier est lié à un souci de médiation culturelle, qui rejoint les réflexions sur la façon de gérer au mieux les conflits entre les diverses composantes du vivre ensemble. Le second vise à approfondir la connaissance des populations roms concernées (lovara, éurara ou kalderasa, de nationalités italienne, française et espagnole). Les deux objectifs sont évidemment reliés, car comprendre les dynamiques conflictuelles exige la connaissance approfondie des acteurs en interaction. Les relations entre résidents tessinois et roms ont évolué dans le temps, avec des oscillations entre le pôle du refus et celui de l'attraction, entre rejet et reconnaissance, méfiance et confiance. Ces variations historiques renvoient à un fondement commun, à une dynamique des oppositions réciproques. L'analyse anthropologique a fait apparaître le rôle ambivalent du conflit dans la production et la reproduction de la relation d'altérité. L'exclusion des roms fournit à certaines tendances politiques locales l'occasion d'apparaître comme les protecteurs des résidents contre les étrangers ; inversement, l'opposition des roms aux gaiés leur permet de resserrer leur communauté et de prévenir l'assimilation. La médiation culturelle peut espérer gérer cette dynamique relationnelle, certainement pas la faire disparaître. Le modèle intégratif traditionnel de l'État- nation se révèle trop étroit pour accueillir la culture rom. Casser la résistance des roms envers le travail salarié et envers la scolarisation obligatoire, entraver leur semi-nomadisme (qui incite aussi leurs rencontres familiales et religieuses), refuser de reconnaître leur organe de justice interne et leur langue, tout cela ne ferait que concourir à leur disparition culturelle. Les roms sont conscients de ces possibilités, raison pour laquelle ils maintiennent une ambivalence relationnelle avec les ga£és, quitte à apparaître comme des « tsiganes indésirables ». Abstract : This research focuses on the Roma people (Vlach) who periodically stay in Italian Switzerland in caravans or camper vans, practising a semi-nomadic lifestyle - a choice based mainly on economic imperatives but also on familial and religious grounds. This study will address two objectives at the same time. The first involves cultural mediation, and considers the best way to manage the existing conflicts between the cultural components of the social environment. The second aims to increase knowledge of the Roma populations under examination - the Italian, French and Spanish Lovara, Éurara or Kalderasa. The two objectives are clearly linked, as a deeper understanding of the people involved is vital if we are to increase understanding of the dynamics of confrontation. The relationships between the residents of the Ticino area and the Roma people have evolved over time, oscillating in varying degrees between rejection and attraction, confrontation and recognition, suspicion and trust. These variations spring from a common base, a dynamic shaped by mutual opposition. The anthropological analysis highlights the ambivalent role of conflict in the production and reproduction of relations of otherness. Excluding the Roma has given some local politicians the opportunity to position themselves as protectors of residents against foreigners. Inversely, the Roma people's opposition to the Gazé strengthens links within their community and prevents assimilation. Cultural mediation may aspire to manage this relational dynamic, but not abolish it. The traditional integrative model of the nation-state has shown itself to be too restrictive to accommodate the Romani culture. Rejecting the Roma's resistance to salaried work and obligatory schooling, obstructing their semi-nomadic lifestyle (one that also involves family and religious assemblies) and refusing to recognise their traditional courts and mother tongue, all that can only contribute to the dilution of their cultural heritage. The Roma are fully aware of these possibilities, which is why they retain a relational ambivalence in their dealings with the Gazé, at the cost of appearing to be "undesirable gypsies".

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Whole-genome duplication (WGD) is usually followed by gene loss and karyotype repatterning. Despite evidence of new adaptive traits associated with WGD, the underpinnings and evolutionary significance of such genome fractionation remain elusive. Here, we use Buckler mustard (Biscutella laevigata) to infer processes that have driven the retention of duplicated genes after recurrent WGDs. In addition to the β- and α-WGD events shared by all Brassicaceae, cytogenetic and transcriptome analyses revealed two younger WGD events that occurred at times of environmental changes in the clade of Buckler mustard (Biscutelleae): a mesopolyploidy event from the late Miocene that was followed by considerable karyotype reshuffling and chromosome number reduction and a neopolyploidy event during the Pleistocene. Although a considerable number of the older duplicates presented signatures of retention under positive selection, the majority of retained duplicates arising from the younger mesopolyploidy WGD event matched predictions of the gene balance hypothesis and showed evidence of strong purifying selection as well as enrichment in gene categories responding to abiotic stressors. Retention of large stretches of chromosomes for both genomic copies supported the hypothesis that cycles of WGD and biased fractionation shaped the genome of this stress-tolerant polypolyloid, promoting the adaptive recruitment of stress-responding genes in the face of environmental challenges.