6,382 research outputs found
Amyloid beta and diabetic pathology cooperatively stimulate cytokine expression in an Alzheimer's mouse model
Background Diabetes is a risk factor for developing Alzheimer's disease (AD); however, the mechanism by which diabetes can promote AD pathology remains unknown. Diabetes results in diverse molecular changes in the brain, including dysregulation of glucose metabolism and loss of cerebrovascular homeostasis. Although these changes have been associated with increased A beta pathology and increased expression of glial activation markers in APPswe/PS1dE9 (APP/PS1) mice, there has been limited characterization, to date, of the neuroinflammatory changes associated with diabetic conditions. Methods To more fully elucidate neuroinflammatory changes associated with diabetes that may drive AD pathology, we combined the APP/PS1 mouse model with either high-fat diet (HFD, a model of pre-diabetes), the genetic db/db model of type 2 diabetes, or the streptozotocin (STZ) model of type 1 diabetes. We then used a multiplexed immunoassay to quantify cortical changes in cytokine proteins. Results Our analysis revealed that pathology associated with either db/db, HFD, or STZ models yielded upregulation of a broad profile of cytokines, including chemokines (e.g., MIP-1 alpha, MIP-1 beta, and MCP-1) and pro-inflammatory cytokines, including IL-1 alpha, IFN-gamma, and IL-3. Moreover, multivariate partial least squares regression analysis showed that combined diabetic-APP/PS1 models yielded cooperatively enhanced expression of the cytokine profile associated with each diabetic model alone. Finally, in APP/PS1xdb/db mice, we found that circulating levels of A beta 1-40, A beta 1-42, glucose, and insulin all correlated with cytokine expression in the brain, suggesting a strong relationship between peripheral changes and brain pathology. Conclusions Altogether, our multiplexed analysis of cytokines shows that Alzheimer's and diabetic pathologies cooperate to enhance profiles of cytokines reported to be involved in both diseases. Moreover, since many of the identified cytokines promote neuronal injury, A beta and tau pathology, and breakdown of the blood-brain barrier, our data suggest that neuroinflammation may mediate the effects of diabetes on AD pathogenesis. Therefore, strategies targeting neuroinflammatory signaling, as well as metabolic control, may provide a promising strategy for intervening in the development of diabetes-associated AD
Both associative activation and thematic extraction count, but thematic false memories are more easily rejected
[EN]The main aim of this study was to analyse the roles played by associative activation and thematic
extraction in the explanation of false memories using the Deese, Roediger, McDermott (DRM)
paradigm. Associative lists with two different types of critical items (CIs) were used: one, the associative
CI, corresponded to the word most strongly primed by the associates in the list and another, the thematic
CI, was the word that best described the theme of the list. Following three different types of encoding
instructions (standard, warning or strategic), false recognition for these two types of CIs was analysed in
either self-paced or speeded response recognition tests. The results showed considerable levels of false
memories for both types of CIs. Even without the quality of being “good themes”, associative CIs
produced high levels of false recognition, which suggests that associative activation plays a prominent
role in false memory formation. More interestingly, thematic CIs were more prone to be edited out,
reinforcing the argument that thematic identifiability has a major role in the rejection of false memories
Ostreopsis cf. ovata y Ostreopsis lenticularis (Dinophyceae: Gonyaulacales) en la Reserva Marina de Galápagos
The genus of benthic dinoflagellates Ostreopsis is of particular interest because some species negatively impact human health and coastal marine ecosystems. Ostreopsis populations from a remote area, such as the Galapagos Marine Reserve with its unique biodiversity, can provide significant data. Samples of epibionthic dinoflagellates were collected from two islands (Santa Cruz and Santa Fé) in 2017. Species of the genera Gambierdiscus, Amphidinium, Coolia and Ostreopsis were found. Ostreopsis strains were isolated to characterize their morphology, molecular biology and toxicity. Three different morphotypes of Ostreopsis based on dorsoventral and width diameters (n=369) were distinguished. The small cell morphotype was dominant in ten samples, with abundances of up to 33405 cells g-1 fresh weight of macroalgae. A total of 16 strains were isolated from field samples with subsequent polymerase chain reaction amplifications of rDNA, 5.8S rDNA and internal transcribed space regions; 13 strains (small cell morphotype) clustered in the O. cf. ovata Atlantic/Indian/Pacific clade; and 3 strains (large cell morphotype) clustered in the Ostreopsis lenticularis genotype from the type locality. The strains proved to be non-toxic. The presence of these genera/species represents a potential threat to marine ecosystems, and it is thus important to consider benthic species in the surveillance of harmful algae blooms in the reserve.El género de los dinoflagelados bentónicos Ostreopsis es de particular interés, porque algunas especies afectan negativamente a la salud humana y a los ecosistemas marinos costeros. Las poblaciones de Ostreopsis en áreas remotas, como la Reserva Marina de Galápagos con su biodiversidad única, pueden proporcionar datos significativos a su estudio. Se recolectaron muestras de dinoflagelados epibentónicos de dos islas (Santa Cruz y Santa Fé) en 2017. Se encontraron especies de los géneros Gambierdiscus, Amphidinium, Coolia y Ostreopsis. Las cepas de Ostreopsis se aislaron para caracterizar su morfología, biología molecular y toxicidad. Se distinguieron tres morfotipos diferentes de Ostreopsis basados en tamaño (n=369). El morfotipo de células pequeñas fue dominante en diez muestras, con abundancias de hasta 33405 células g–1 de peso fresco de macroalgas. Se aisló un total de 16 cepas y se secuenciaron las regiones de rDNA, 5.8S y ITS para el estudio filogenético. Trece cepas pertenecieron al morfotipo de células pequeñas agrupadas en el clado O. cf. ovata Atlántico/Índio/Pacífico y tres cepas al morfotipo de células grandes agrupadas en el clado Ostreopsis lenticularis. Ninguna de las cepas aisladas resultó ser tóxica. La presencia de estos géneros/especies representa una amenaza potencial para los ecosistemas marinos, por lo que es importante tener en cuenta las especies bentónicas en la vigilancia de la proliferación de algas nocivas en la reserva
Ostreopsis cf. ovata and Ostreopsis lenticularis (Dinophyceae: Gonyaulacales) in the Galapagos Marine Reserve
The genus of benthic dinoflagellates Ostreopsis is of particular interest because some species negatively impact human health and coastal marine ecosystems. Ostreopsis populations from a remote area, such as the Galapagos Marine Reserve with its unique biodiversity, can provide significant data. Samples of epibionthic dinoflagellates were collected from two islands (Santa Cruz and Santa Fé) in 2017. Species of the genera Gambierdiscus, Amphidinium, Coolia and Ostreopsis were found. Ostreopsis strains were isolated to characterize their morphology, molecular biology and toxicity. Three different morphotypes of Ostreopsis based on dorsoventral and width diameters (n=369) were distinguished. The small cell morphotype was dominant in ten samples, with abundances of up to 33405 cells g-1 fresh weight of macroalgae. A total of 16 strains were isolated from field samples with subsequent polymerase chain reaction amplifications of rDNA, 5.8S rDNA and internal transcribed space regions; 13 strains (small cell morphotype) clustered in the O. cf. ovata Atlantic/Indian/Pacific clade; and 3 strains (large cell morphotype) clustered in the Ostreopsis lenticularis genotype from the type locality. The strains proved to be non-toxic. The presence of these genera/species represents a potential threat to marine ecosystems, and it is thus important to consider benthic species in the surveillance of harmful algae blooms in the reserve.El género de los dinoflagelados bentónicos Ostreopsis es de particular interés, porque algunas especies afectan negativamente a la salud humana y a los ecosistemas marinos costeros. Las poblaciones de Ostreopsis en áreas remotas, como la Reserva Marina de Galápagos con su biodiversidad única, pueden proporcionar datos significativos a su estudio. Se recolectaron muestras de dinoflagelados epibentónicos de dos islas (Santa Cruz y Santa Fé) en 2017. Se encontraron especies de los géneros Gambierdiscus, Amphidinium, Coolia y Ostreopsis. Las cepas de Ostreopsis se aislaron para caracterizar su morfología, biología molecular y toxicidad. Se distinguieron tres morfotipos diferentes de Ostreopsis basados en tamaño (n=369). El morfotipo de células pequeñas fue dominante en diez muestras, con abundancias de hasta 33405 células g–1 de peso fresco de macroalgas. Se aisló un total de 16 cepas y se secuenciaron las regiones de rDNA, 5.8S y ITS para el estudio filogenético. Trece cepas pertenecieron al morfotipo de células pequeñas agrupadas en el clado O. cf. ovata Atlántico/Índio/Pacífico y tres cepas al morfotipo de células grandes agrupadas en el clado Ostreopsis lenticularis. Ninguna de las cepas aisladas resultó ser tóxica. La presencia de estos géneros/especies representa una amenaza potencial para los ecosistemas marinos, por lo que es importante tener en cuenta las especies bentónicas en la vigilancia de la proliferación de algas nocivas en la reserva.info:eu-repo/semantics/publishedVersio
“Identify-to-reject”: A specific strategy to avoid false memories in the DRM paradigm
[EN]Previous research using the Deese–Roediger–
McDermott (DRM) paradigm has shown that lists of
associates in which the critical words were easily identified
as the themes of the lists produce lower levels of false
memories in adults. In an attempt to analyze whether this
effect is due to the application of a specific memory-editing
process (the identify-to-reject strategy), two experiments
manipulated variables that are likely to disrupt this strategy
either at encoding or at retrieval. In Experiment 1, lists were
presented at a very fast presentation rate to reduce the
possibility of identifying the missing critical word as the
theme of the list, and in Experiment 2, participants were
pressed to give yes/no recognition answers within a very short
time. The results showed that both of these manipulations
disrupted the identifiability effect, indicating that the identify to-reject strategy and theme identifiability play a major role in
the rejection of false memories in the DRM paradigm
Vegetation water use based on a thermal and optical remote sensing model in the mediterranean region of Doñana
Terrestrial evapotranspiration (ET) is a central process in the climate system, is a major component in the terrestrial water budget, and is responsible for the distribution of water and energy on land surfaces especially in arid and semiarid areas. In order to inform water management decisions especially in scarce water environments, it is important to assess ET vegetation use by differentiating irrigated socio-economic areas and natural ecosystems. The global remote sensing ET product MOD16 has proven to underestimate ET in semiarid regions where ET is very sensitive to soil moisture. The objective of this research was to test whether a modified version of the remote sensing ET model PT-JPL, proven to perform well in drylands at Eddy Covariance flux sites using the land surface temperature as a proxy to the surface moisture status (PT-JPL-thermal), could be up-scaled at regional levels introducing also a new formulation for net radiation from various MODIS products. We applied three methods to track the spatial and temporal characteristics of ET in the World Heritage UNESCO Doñana region: (i) a locally calibrated hydrological model (WATEN), (ii) the PT-JPL-thermal, and (iii) the global remote sensing ET product MOD16. The PT-JPL-thermal showed strong agreement with the WATEN ET in-situ calibrated estimates (ρ = 0.78, ρ1month-lag = 0.94) even though the MOD16 product did not (ρ = 0.48). The PT-JPL-thermal approach has proven to be a robust remote sensing model for detecting ET at a regional level in Mediterranean environments and it requires only air temperature and incoming solar radiation from climatic databases apart from freely available satellite products
The evolution of Balmer jump selected galaxies in the ALHAMBRA survey
We present a new color-selection technique, based on the Bruzual & Charlot
models convolved with the bands of the ALHAMBRA survey, and the redshifted
position of the Balmer jump to select star-forming galaxies in the redshift
range 0.5 < z < 1.5. These galaxies are dubbed Balmer jump Galaxies BJGs. We
apply the iSEDfit Bayesian approach to fit each detailed SED and determine
star-formation rate (SFR), stellar mass, age and absolute magnitudes. The mass
of the haloes where these samples reside are found via a clustering analysis.
Five volume-limited BJG sub-samples with different mean redshifts are found to
reside in haloes of median masses slightly
increasing toward z=0.5. This increment is similar to numerical simulations
results which suggests that we are tracing the evolution of an evolving
population of haloes as they grow to reach a mass of at z=0.5. The likely progenitors of our samples at z3 are Lyman
Break Galaxies, which at z2 would evolve into star-forming BzK galaxies,
and their descendants in the local Universe are elliptical galaxies.Hence, this
allows us to follow the putative evolution of the SFR, stellar mass and age of
these galaxies. From z1.0 to z0.5, the stellar mass of the volume
limited BJG samples nearly does not change with redshift, suggesting that major
mergers play a minor role on the evolution of these galaxies. The SFR evolution
accounts for the small variations of stellar mass, suggesting that star
formation and possible minor mergers are the main channels of mass assembly.Comment: 14 pages, 10 figures. Submitted to A&A. It includes first referee's
comments. Abstract abridged due to arXiv requirement
Iso-spectral potential and inflationary quantum cosmology
Using the factorization approach of quantum mechanics, we obtain a family of
isospectral scalar potentials for power law inflationary cosmology. The
construction is based on a scattering Wheeler-DeWitt solution. These
iso-spectrals have new features, they give a mechanism to end inflation, as
well as the possibility to have new inflationary epochs. The procedure can be
extended to other cosmological models.Comment: 14 pages, 5 figure
A large accumulation of avian eggs from the Late Cretaceous of Patagonia (Argentina) reveals a novel nesting strategy in Mesozoic birds
We report the first evidence for a nesting colony of Mesozoic birds on Gondwana: a fossil accumulation in Late Cretaceous rocks mapped and collected from within the campus of the National University of Comahue, Neuquén City, Patagonia (Argentina). Here, Cretaceous ornithothoracine birds, almost certainly Enanthiornithes, nested in an arid, shallow basinal environment among sand dunes close to an ephemeral water-course. We mapped and collected 65 complete, near-complete, and broken eggs across an area of more than 55 m2. These eggs were laid either singly, or occasionally in pairs, onto a sandy substrate. All eggs were found apparently in, or close to, their original nest site; they all occur within the same bedding plane and may represent the product of a single nesting season or a short series of nesting attempts. Although there is no evidence for nesting structures, all but one of the Comahue eggs were half-buried upright in the sand with their pointed end downwards, a position that would have exposed the pole containing the air cell and precluded egg turning. This egg position is not seen in living birds, with the exception of the basal galliform megapodes who place their eggs within mounds of vegetation or burrows. This accumulation reveals a novel nesting behaviour in Mesozoic Aves that was perhaps shared with the non-avian and phylogenetically more basal troodontid theropods.Fil: Fernández, Mariela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Patagonia Norte. Instituto de Investigación en Biodiversidad y Medioambiente; ArgentinaFil: Garcia, Rodolfo Andres. Universidad Nacional de Rio Negro. Sede Alto Valle. Instituto de Investigaciones En Paleobiologia y Geologia; ArgentinaFil: Fiorelli, Lucas Ernesto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Regional de Investigaciones Cientificas y Transferencia Tecnológica de Anillaco; ArgentinaFil: Scolaro, Jose Alejandro. Universidad Nacional de la Patagonia "san Juan Bosco"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; ArgentinaFil: Salvador, Rodrigo B.. Universidade de Sao Paulo. Instituto Quãmica de Sao Carlos; BrasilFil: Cotaro, Carlos N.. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; ArgentinaFil: Kaiser, Gary W.. Royal British Columbia Museum; CanadáFil: Dyke, Gareth J.. University Of Southampton; Reino Unid
Solutions of the Strominger System via Stable Bundles on Calabi-Yau Threefolds
We prove that a given Calabi-Yau threefold with a stable holomorphic vector
bundle can be perturbed to a solution of the Strominger system provided that
the second Chern class of the vector bundle is equal to the second Chern class
of the tangent bundle. If the Calabi-Yau threefold has strict SU(3) holonomy
then the equations of motion derived from the heterotic string effective action
are also satisfied by the solutions we obtain.Comment: 19 pages, late
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