Search results for "TTR"
showing 10 items of 3945 documents
Retrieving infinite numbers of patterns in a spin-glass model of immune networks
2013
The similarity between neural and immune networks has been known for decades, but so far we did not understand the mechanism that allows the immune system, unlike associative neural networks, to recall and execute a large number of memorized defense strategies {\em in parallel}. The explanation turns out to lie in the network topology. Neurons interact typically with a large number of other neurons, whereas interactions among lymphocytes in immune networks are very specific, and described by graphs with finite connectivity. In this paper we use replica techniques to solve a statistical mechanical immune network model with `coordinator branches' (T-cells) and `effector branches' (B-cells), a…
Octopamine Shifts the Behavioral Response From Indecision to Approach or Aversion in Drosophila melanogaster
2018
Animals must make constant decisions whether to respond to external sensory stimuli or not to respond. The activation of positive and/or negative reinforcers might bias the behavioral response towards approach or aversion. To analyze whether the activation of the octopaminergic neurotransmitter system can shift the decision between two identical odor sources, we active in Drosophila melanogaster different sets of octopaminergic neurons using optogenetics and analyze the choice of the flies using a binary odor trap assay. We show that the release of octopamine from a set of neurons and not acetylcholine acts as positive reinforcer for one food odor source resulting in attraction. The activat…
The 5′ Untranslated Region of the EFG1 Transcript Promotes Its Translation To Regulate Hyphal Morphogenesis in Candida albicans
2018
ABSTRACTExtensive 5’ untranslated regions (UTR) are a hallmark of transcripts determining hyphal morphogenesis inCandida albicans.The major transcripts of theEFG1gene, which are responsible for cellular morphogenesis and metabolism, contain a 5’ UTR of up to 1170 nt. Deletion analyses of the 5’ UTR revealed a 218 nt sequence that is required for production of the Efg1 protein and its functions in filamentation, without lowering the level and integrity of theEFG1transcript. Polysomal analyses revealed that the 218 nt 5’ UTR sequence is required for efficient translation of the Efg1 protein. Replacement of theEFG1ORF by the heterologous reporter geneCaCBGlucconfirmed the positive regulatory i…
Transfer Free Energies of Test Proteins Into Crowded Protein Solutions Have Simple Dependence on Crowder Concentration
2019
The effects of macromolecular crowding on the thermodynamic properties of test proteins are determined by the latter's transfer free energies from a dilute solution to a crowded solution. The transfer free energies in turn are determined by effective protein-crowder interactions. When these interactions are modeled at the all-atom level, the transfer free energies may defy simple predictions. Here we investigated the dependence of the transfer free energy (Δμ) on crowder concentration. We represented both the test protein and the crowder proteins atomistically, and used a general interaction potential consisting of hard-core repulsion, non-polar attraction, and solvent-screened electrostati…
Mitigating anticipated effects of systematic errors supports sister-group relationship between Xenacoelomorpha and Ambulacraria.
2019
International audience; Xenoturbella and the acoelomorph worms (Xenacoelomorpha) are simple marine animals with controversial affinities. They have been placed as the sister group of all other bilaterian animals (Nephrozoa hypothesis), implying their simplicity is an ancient characteristic ]; alternatively, they have been linked to the complex Ambulacraria (echinoderms and hemichordates) in a clade called the Xenambulacraria , suggesting their simplicity evolved by reduction from a complex ancestor. The difficulty resolving this problem implies the phylogenetic signal supporting the correct solution is weak and affected by inadequate modeling, creating a misleading non-phylogenetic signal. …
Why Are New Drugs Expensive and How Can They Stay Affordable?
2019
Increasing life expectancy leading to a higher median age causes an increasing need for healthcare resources, which is aggravated by an increasing prevalence of preventable diseases such as type 2 diabetes. This includes increasing expenditures for medicines, although these increases when expressed as a share of overall societal wealth are more moderate than often claimed. An increasing use of generic medicines (currently about 90% of all prescriptions) means that costs for discovery and development of innovative drugs must be recovered on a shrinking percentage of prescriptions. However, the key challenge to affordable drugs is exponentially increasing costs to bring a new medicine to the …
Glutamate and opioid antagonists modulate dopamine levels evoked by innately attractive male chemosignals in the nucleus accumbens of female rats
2017
Sexual chemosignals detected by vomeronasal and olfactory systems mediate intersexual attraction in rodents, and act as a natural reinforcer to them. The mesolimbic pathway processes natural rewards, and the nucleus accumbens receives olfactory information via glutamatergic projections from the amygdala. Thus, the aim of this study was to investigate the involvement of the mesolimbic pathway in the attraction toward sexual chemosignals. Our data show that female rats with no previous experience with males or their chemosignals display an innate preference for male-soiled bedding. Focal administration of the opioid antagonist b-funaltrexamine into the posterior ventral tegmental area does no…
Drosophila Food-Associated Pheromones: Effect of Experience, Genotype and Antibiotics on Larval Behavior
2016
International audience; Animals ubiquitously use chemical signals to communicate many aspects of their social life. These chemical signals often consist of environmental cues mixed with species-specific signals-pheromones-emitted by conspecifics. During their life, insects can use pheromones to aggregate, disperse, choose a mate, or find the most suitable food source on which to lay eggs. Before pupariation, larvae of several Drosophila species migrate to food sources depending on their composition and the presence of pheromones. Some pheromones derive from microbiota gut activity and these food-associated cues can enhance larval attraction or repulsion. To explore the mechanisms underlying…
Congruencia en conocimientos y educación afectivo-sexual en personas con DI
2018
En la educación de las personas con diversidad funcional intelectual (DFI) es importante que los principales agentes implicados (usuarios/as, padres y profesionales que trabajan con ellos) posean criterios comunes acerca de los objetivos educativos en general, y especialmente, en el área de la sexualidad. Sin embargo, las tres perspectivas no siempre son coincidentes con las consecuencias que se derivan de ello. Teniendo en cuenta la importancia de la identificación de necesidades y metas comunes, planteamos este trabajo con el objetivo de conocer el grado de concordancia entre: 1) los conocimientos que los usuarios tienen sobre sexualidad y la que los padres y profesionales les atribuyen y…
Exogenous sources of regional industrial change
2017
The role of exogenous sources of new path development has been underplayed in the literature on regional industrial change so far. The aim of this article is to explore in a conceptual way under which conditions and in what ways non-local knowledge can lead to new path development in different regional innovation systems (RISs). We distinguish between organizationally thick and diversified RISs, thick and specialized RISs and thin RISs and argue that these types vary substantially in their needs for exogenous sources as well as in their capacities to attract and absorb knowledge generated elsewhere.