Reconstructing mid-to-recent Holocene paleoenvironments in the vicinity of ancient Amarynthos (Euboea, Greece).

This article examines the shoreline evolution and human occupation in the vicinity of the important archeological site of Amarynthos (Euboea Island, Greece) over the last six millennia. Archeological evidence indicates a continuous occupation of the site from the Bronze Age to the Roman period and the site is well-known, thanks to the existence of a sanctuary dedicated to the goddess Artemis. Based on the study of four boreholes, a paleogeographic reconstruction of the coastal landscape is proposed. Facies were determined based on mollusc identification, and sedimentology based on grain-size measurements (hand sieving for the fraction above 2 mm and LASER technique for particles below 2 mm) and loss-on-ignition. In addition, a series of 12 AMS radiocarbon dates define a reliable chronostratigraphy. Results suggest the presence of a fully marine environment from the early Holocene to ca. 2600-2400 cal. BC, which developed into a brackish environment from ca. 2600-2400 cal. BC to ca. 750 cal. BC due to the deltaic progradation of the nearby stream (Sarandapotamos River). From ca. 750 cal. BC onward, coastal swamps prevailed in the study area. Human-environmental interaction is discussed and particular attention is paid to the paleolandscape configuration of Amarynthos.

Mid Holocene in Sant Julià de Boada (Baix Empordà, Girona): Stratigraphical sequence and paleoenvironmental records of the paludal deposits

Descripció de la seqüència estratigràfica i dels registres paleoambientals dels sediments holocens de Sant Julià de Boada

Nrf2 links epidermal barrier function with antioxidant defense.

The skin provides an efficient permeability barrier and protects from microbial invasion and oxidative stress. Here, we show that these essential functions are linked through the Nrf2 transcription factor. To test the hypothesis that activation of Nrf2 provides skin protection under stress conditions, we determined the consequences of pharmacological or genetic activation of Nrf2 in keratinocytes. Surprisingly, mice with enhanced Nrf2 activity in keratinocytes developed epidermal thickening, hyperkeratosis and inflammation resembling lamellar ichthyosis. This resulted from upregulation of the cornified envelope proteins small proline-rich proteins (Sprr) 2d and 2h and of secretory leukocyte peptidase inhibitor (Slpi), which we identified as novel Nrf2 targets in keratinocytes. Since Sprrs are potent scavengers of reactive oxygen species and since Slpi has antimicrobial activities, their upregulation contributes to Nrf2's protective function. However, it also caused corneocyte fragility and impaired desquamation, followed by alterations in the epidermal lipid barrier, inflammation and overexpression of mitogens that induced keratinocyte hyperproliferation. These results identify an unexpected role of Nrf2 in epidermal barrier function, which needs to be considered for pharmacological use of Nrf2 activators.

Mètriques barrier walkthrough per a persones sordes

En aquest article es presenta un conjunt de mètriques manuals, les mètriques BAW, per avaluar l'accessibilitat web d'una pàgina dins d'un context específic i ofereix la possibilitat de quantificar el grau d'accessibilitat amb una fórmula.

Toll-Interacting Protein Modulates Gut Flora Composition, Epithelial Barrier Integrity and Susceptibility to Colitis

Toll-like receptor ( TLR) s ignals are key to maintaining hostmicrobial i nteractions. T he T oll-interacting-protein (Tollip) is a ubiquitously-expressed inhibitor of inflammasome a nd TLR signaling. W e hypothesized that T ollip might control g ut homeostasis. G enetic ablation of T ollip d id not lead to spontaneous colitis b ut h ad d ramatic c onsequences on t he intestinal expression of the α-defensin cryptidin 4 and the C-type lectin R EGIIIβ. These c hanges were associated with intestinal dysbiosis a nd e nhanced colonization b y segmented filamentous bacteria - a k ey p ro-inflammatory component of the microbiota. Tollip deficiency increased susceptibility to dextran sulfate sodium (DSS) colitis and aggravated chronic Th17-driven colitis in IL-10-/- mice. Flora d epletion w ith a ntibiotics in T ollip-/- mice w as not sufficient to restore DSS colitis susceptibility and deletion of Tollip in n on-hematopoietic c ells using bone-marrow chimeras w as sufficient to increase s usceptibility t o DSS colitis. After D SS administration, we o bserved several e pithelial defects i n Tollip-/- mice including early tight junctions disruption, increased epithelial apoptosis, and increased intestinal permeability. Overall, our data show that T ollip significantly impacts intestinal h omeostasis by controlling b acterial ecology and intestinal r esponse to chemical and immunological stresses.

Characterization of insulators and barrier elements for gene therapy

Gene transfer that relies on integrating vectors often suffers from epigenetic or regulatory effects that influence the expression of the therapeutic gene and=or of cellular genes located near the vector integration site in the chromosome. Insulator elements act to block gene activation by enhancers, while chromatin domain boundary or barrier sequences prevent gene-silencing effects. At present, the modes of action of insulator and barriers are poorly understood, and their use in the context of gene therapies remains to be documented. Using combinations of reporter genes coding for indicator fluorescent proteins, we constructed assay systems that allow the quantification of the insulator or barrier activities of genetic elements in individual cells. This presentation will illustrate how these assay systems were used to identify short DNA elements that insulate nearby genes from activation by viral vector elements, and=or that block the propagation of a silent chromatin structure that leads to gene silencing. We will show that some barrier elements do not merely block repressive effects, but that they can act to stabilize and sustain transgene expression. We will illustrate that this may be beneficial when transgenes are introduced into stem or precursor cells using non-viral vectors, where later differentiation may lead to the silencing of the therapeutic gene. We will show that these elements can be used to maintain efficient transgene expression upon the differentiation of murine precursor cells towards myofibers, in a model of cell therapy for muscle dystrophies.

A receptor-like kinase mutant with absent endodermal diffusion barrier displays selective nutrient homeostasis defects.

The endodermis represents the main barrier to extracellular diffusion in plant roots, and it is central to current models of plant nutrient uptake. Despite this, little is known about the genes setting up this endodermal barrier. In this study, we report the identification and characterization of a strong barrier mutant, schengen3 (sgn3). We observe a surprising ability of the mutant to maintain nutrient homeostasis, but demonstrate a major defect in maintaining sufficient levels of the macronutrient potassium. We show that SGN3/GASSHO1 is a receptor-like kinase that is necessary for localizing CASPARIAN STRIP DOMAIN PROTEINS (CASPs)--major players of endodermal differentiation--into an uninterrupted, ring-like domain. SGN3 appears to localize into a broader band, embedding growing CASP microdomains. The discovery of SGN3 strongly advances our ability to interrogate mechanisms of plant nutrient homeostasis and provides a novel actor for localized microdomain formation at the endodermal plasma membrane.

The optimal dividend barrier in the Gamma-Omega model

In the traditional actuarial risk model, if the surplus is negative, the company is ruined and has to go out of business. In this paper we distinguish between ruin (negative surplus) and bankruptcy (going out of business), where the probability of bankruptcy is a function of the level of negative surplus. The idea for this notion of bankruptcy comes from the observation that in some industries, companies can continue doing business even though they are technically ruined. Assuming that dividends can only be paid with a certain probability at each point of time, we derive closed-form formulas for the expected discounted dividends until bankruptcy under a barrier strategy. Subsequently, the optimal barrier is determined, and several explicit identities for the optimal value are found. The surplus process of the company is modeled by a Wiener process (Brownian motion).

Shot-noise suppression in Schottky barrier diodes

We give a theoretical interpretation of the noise properties of Schottky barrier diodes based on the role played by the long range Coulomb interaction. We show that at low bias Schottky diodes display shot noise because the presence of the depletion layer makes the effects of the Coulomb interaction negligible on the current fluctuations. When the device passes from barrier to flat band conditions, the Coulomb interaction becomes active, thus introducing correlation between different current fluctuations. Therefore, the crossover between shot and thermal noise represents the suppression due to long range Coulomb interaction of the otherwise full shot noise. Similar ideas can be used to interpret the noise properties of other semiconductor devices.

Time of ruin in a risk model with generalized Erlang (n) interclaim times and a constant dividend barrier

In this paper we analyze the time of ruin in a risk process with the interclaim times being Erlang(n) distributed and a constant dividend barrier. We obtain an integro-differential equation for the Laplace Transform of the time of ruin. Explicit solutions for the moments of the time of ruin are presented when the individual claim amounts have a distribution with rational Laplace transform. Finally, some numerical results and a compare son with the classical risk model, with interclaim times following an exponential distribution, are given.

Boring activity of Epibionts in an Early Holocene molluscan fauna of Spanish Catalunya

Using X-Ray techniques, the boring activities of various Invertebrates on Bivalvia of wmian age were studied. Emphasis is placed on the boring activity of Porifera and their apparent preselection of the species bored, based on: a) the mineralogical composition, and/or b) the microstucture, andlor c) some special environmental conditions, or d) combinations of these three posibilities.

Barrier for the reaction X20+ + X20+ -> X402+ in alkali-metal clusters related to electron density at the bond midpoint of the supermolecule (X20+)2

Using the extended Thomas-Fermi version of density-functional theory (DFT), calculations are presented for the barrier for the reaction Na20++Na20+¿Na402+. The deviation from the simple Coulomb barrier is shown to be proportional to the electron density at the bond midpoint of the supermolecule (Na20+)2. An extension of conventional quantum-chemical studies of homonuclear diatomic molecular ions is then effected to apply to the supermolecular ions of the alkali metals. This then allows the Na results to be utilized to make semiquantitative predictions of position and height of the maximum of the fusion barrier for other alkali clusters. These predictions are confirmed by means of similar DFT calculations for the K clusters.

Compétences en santé déficientes: obstacle à une prise en charge optimale [Low health literacy: barrier to optimal care].

Les carences en compétences en santé touchent principalement certaines populations à risques en limitant l'accès aux soins, l'interaction avec les soignants et l'autoprise en charge. L'utilisation systématique d'instruments de dépistage n'est pas recommandée et les interventions préconisées en pratique consistent plutôt à diminuer les obstacles entravant la communication patient-soignant. Il s'agit d'intégrer non seulement les compétences de la population en matière de santé mais aussi les compétences communicationnelles d'un système de santé qui se complexifie. Health literacy is defined as "the degree to which individuals have the capacity to obtain, process, and understand basic health information and services needed to make appropriate health decisions." Low health literacy mainly affects certain populations at risk limiting access to care, interaction with caregivers and self-management. If there are screening tests, their routine use is not advisable and recommended interventions in practice consist rather to reduce barriers to patient-caregiver communication. It is thus important to include not only population's health literacy but also communication skills of a health system wich tend to become more complex.