366 research outputs found

    Dark Sectors with Mass Thresholds Face Cosmological Datasets

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    Interacting dark sectors may undergo changes in the number of their relativistic species during the early universe, due to a mass threshold mm (similar to changes in the Standard Model bath), and in doing so affect the cosmic history. When such changes occur close to recombination, i.e., for m(0.110) eVm\sim (0.1-10)~\text{eV}, the stringent bound on the effective number of neutrino species, NeffN_{\text{eff}}, can be relaxed and the value of the Hubble expansion rate H0H_0 inferred from Cosmic Microwave Background (CMB) observations raised. We search for such sectors (with and without mass thresholds) in the latest cosmological datasets, including the full-shape (FS) of BOSS DR12 galaxy power spectrum. We perform a detailed analysis, accounting for the choice of prior boundaries and additionally exploring the possible effects of dark sector interactions with (a fraction of) the dark matter. We find ΔNeff0.55(0.46)\Delta N_{\text{eff}}\leq 0.55\, (0.46) at 95% C.L. with (without) a mass threshold. While a significantly larger Hubble rate is achieved in this scenario, H0=69.011.1+0.66H_0=69.01^{+0.66}_{-1.1}, the overall fit to CMB+FS data does not provide a compelling advantage over the Λ\LambdaCDM model. Furthermore, we find that dark matter interactions with the dark sector do not significantly improve the (matter fluctuations) S8S_8 tension with respect to the Λ\LambdaCDM model. Our work provides model-independent constraints on (decoupled) dark sectors with mass thresholds around the eV scale.Comment: 18 + 18 pages, 38 figures and table

    New onset, transient and stable motoric cognitive risk syndrome: Clinical characteristics and association with incidence of probable dementia in the NuAge cohort.

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    BACKGROUND: Motoric cognitive risk syndrome (MCR) is a pre-dementia stage. The existence of stable and transient MCR, their related clinical characteristics and their association with incident dementia is a matter of debate. OBJECTIVE: This study aims to examine the clinical characteristics and the time course associated with new onset, transient and stable MCR, and their association with incidence of probable dementia in community-dwelling older adults living in the province of Quebec (Canada). DESIGN: Quebec elderly population-based observational cohort study with 3 years of follow-up. SETTING: Community dwellers. SUBJECTS: A subset of participants (n = 1,113) from the “Quebec Longitudinal Study on Nutrition and Successful Aging” (NuAge) cohort. METHODS: Participants with MCR were identified at baseline and after 1 year of follow-up. Socio-demographic characteristics, 30-item Geriatric depression scale (GDS) score, cardiovascular risk factors and diseases were recorded at baseline. Incidence of probable dementia was measured at annual follow-up visits over a 3-year period. RESULTS: Over the period of the first year of follow-up, the prevalence of MCR was 8.5% with 4.3% having new onset MCR, 2.8% transient MCR and 1.4% stable MCR. A higher 30-item GDS score was reported with new onset and transient MCR, and the highest prevalence of cerebrovascular diseases was shown with stable MCR compared to non-MCR participants (p < 0.05). MCR was associated with overall incidence of probable dementia, regardless of its status (Hazard Ratio ≥ 1.86, p ≤ 0.034). CONCLUSION: Greater prevalence of depressive symptoms and cerebrovascular diseases were reported, respectively, with new onset and transient MCR, and stable MCR. The association of MCR with incidence of probable dementia remains significant, regardless of MCR subtypes

    PLoS One

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    MOTIVATION: The recent revolution in new sequencing technologies, as a part of the continuous process of adopting new innovative protocols has strongly impacted the interpretation of relations between phenotype and genotype. Thus, understanding the resulting gene sets has become a bottleneck that needs to be addressed. Automatic methods have been proposed to facilitate the interpretation of gene sets. While statistical functional enrichment analyses are currently well known, they tend to focus on well-known genes and to ignore new information from less-studied genes. To address such issues, applying semantic similarity measures is logical if the knowledge source used to annotate the gene sets is hierarchically structured. In this work, we propose a new method for analyzing the impact of different semantic similarity measures on gene set annotations. RESULTS: We evaluated the impact of each measure by taking into consideration the two following features that correspond to relevant criteria for a "good" synthetic gene set annotation: (i) the number of annotation terms has to be drastically reduced and the representative terms must be retained while annotating the gene set, and (ii) the number of genes described by the selected terms should be as large as possible. Thus, we analyzed nine semantic similarity measures to identify the best possible compromise between both features while maintaining a sufficient level of details. Using Gene Ontology to annotate the gene sets, we obtained better results with node-based measures that use the terms' characteristics than with measures based on edges that link the terms. The annotation of the gene sets achieved with the node-based measures did not exhibit major differences regardless of the characteristics of terms used

    Application of Recurrent Neural Networks for Drought Projections in California

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    We use recurrent neural networks (RNNs) to investigate the complex interactions between the long-term trend in dryness and a projected, short but intense, period of wetness due to the 2015-2016 El Niño. Although it was forecasted that this El Niño season would bring significant rainfall to the region, our long-term projections of the Palmer Z Index (PZI) showed a continuing drought trend, contrasting with the 1998-1999 El Niño event. RNN training considered PZI data during 1896-2006 that was validated against the 2006-2015 period to evaluate the potential of extreme precipitation forecast. We achieved a statistically significant correlation of 0.610 between forecasted and observed PZI on the validation set for a lead time of 1 month. This gives strong confidence to the forecasted precipitation indicator. The 2015-2016 El Niño season proved to be relatively weak as compared with the 1997-1998, with a peak PZI anomaly of 0.242 standard deviations below historical averages, continuing drought conditions

    Motoric Cognitive Risk Syndrome: Could It Be Defined Through Increased Five-Times-Sit-to-Stand Test Time, Rather Than Slow Walking Speed?

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    Background: Slow walking speed, time to perform the five-times-sit-to-stand (FTSS) test and motoric cognitive risk syndrome (MCR; defined as slow gait speed combined with subjective cognitive complaint) have been separately used to screen older individuals at risk of cognitive decline. This study seeks to (1) compare the characteristics of older individuals with MCR, as defined through slow walking speed and/or increased FTSS time; and (2) examine the relationship between MCR and its motor components as well as amnestic (a-MCI) and non-amnestic (na-MCI) Mild Cognitive Impairment. Methods: A total of 633, individuals free of dementia, were selected from the cross-sectional "Gait and Alzheimer Interactions Tracking" study. Slow gait speed and increased FTSS time were used as criteria for the definition of MCR. Participants were separated into five groups, according to MCR status: MCR as defined by (1) slow gait speed exclusively (MCRs); (2) increased FTSS time exclusively (MCRf); (3) slow gait speed and increased FTSS time (MCRsaf); (4) MCR; irrespective of the mobility test used (MCRsof); and (5) the absence of MCR. Cognitive status (i.e., a-MCI, na-MCI, cognitively healthy) was also determined. Results: The prevalence of MCRs was higher, when compared to the prevalence of MCRf (12.0% versus 6.2% with P ≤ 0.001). There existed infrequent overlap (2.4%) between individuals exhibiting MCRs and MCRf, and frequent overlap between individuals exhibiting MCRs and na-MCI (up to 50%). a-MCI and na-MCI were negatively [odd ratios (OR) ≤ 0.17 with P ≤ 0.019] and positively (OR ≥ 2.41 with P ≤ 0.019) related to MCRs, respectively. Conclusion: Individuals with MCRf are distinct from those with MCRs. MCRf status does not relate to MCI status in the same way that MCRs does. MCRs is related negatively to a-MCI and positively to na-MCI. These results suggest that FTTS cannot be used to define MCR when the goal is to predict the risk of cognitive decline, such as future dementia

    Composición química parcial y actividad antimicrobiana de extractos de Daucus critinus Desf

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    The chemical composition of fatty acids and the unsaponifiable fraction of the roots, leaves and stems from Daucus crinitus Desf. were, determined using gas chromatography (GC) and gas chromatography-Mass Spectrometry (GC-MS). The fatty acid fractions of different organs (leaves, stems and roots) were characterized by lauric acid (17.9, 17.5 and 18.1 % respectively) and other long chain fatty acids (until C22). Qualitative and quantitative differences were reported between the unsaponifiable fractions of different organs from D. crinitus. The unsaponifiable fractions of the leaves, roots and stem showed high amounts of aliphatic components (83.4%, 87.2% and 91.4%, respectively). The monoterpen, diterpen and sesquiterpen components were only present in small percentages. The antimicrobial properties of the D. critinus extracts were tested on four different microorganisms. These extracts were found to be active against Bacillus cereus, Staphylococcus aureus, Escherichia coli and Candida albicans.La composición química de los ácidos grasos y la fracción insaponificable de raíces, hojas, y tallos de Daucus crinitus Desf. fueron establecidas utilizando cromatografía de gases (GC) y cromatografía de gases-espectrometría de masas (GC-MS). La fracción de ácidos grasos de los diferentes órganos (hojas, tallos y raíces) se caracterizó por el ácido láurico (17.9, 17.5 y 18.1% respectivamente) y otros ácidos grasos de cadena larga (hasta C22). Diferencias cualitativas y cuantitativas se registraron entre las fracciones insaponificable de los diferentes órganos de D. crinitus. De hecho, las fracciones insaponificable de la raíz, de la hoja y del tallo mostraron cantidades altas de componentes alifáticos (83.4%, 87.2% y 91.4%, respectivamente). Los componentes monoterpénicos, diterpénicos y sesquiterpénicos solo estuvieron presentes en un pequeño porcentaje. Las propiedades antimicrobianas de los extractos de D. critinus fueron ensayadas en cuatro microorganismos diferentes. Estos extractos fueron activos contra Bacillus cereus, Staphylococcus aureus, Escherichia coli y Candida albicans

    Methylation-state-specific recognition of histones by the MBT repeat protein L3MBTL2.

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    The MBT repeat has been recently identified as a key domain capable of methyl-lysine histone recognition. Functional work has pointed to a role for MBT domain-containing proteins in transcriptional repression of developmental control genes such as Hox genes. In this study, L3MBTL2, a human homolog of Drosophila Sfmbt critical for Hox gene silencing, is demonstrated to preferentially recognize lower methylation states of several histone-derived peptides through its fourth MBT repeat. High-resolution crystallographic analysis of the four MBT repeats of this protein reveals its unique asymmetric rhomboid architecture, as well as binding mechanism, which preclude the interaction of the first three MBT repeats with methylated peptides. Structural elucidation of an L3MBTL2-H4K20me1 complex and comparison with other MBT-histone peptide complexes also suggests that an absence of distinct surface contours surrounding the methyl-lysine-binding pocket may underlie the lack of sequence specificity observed for members of this protein family
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