| 1. |
- Jin, Shoko, et al.
(författare)
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The wide-field, multiplexed, spectroscopic facility WEAVE : Survey design, overview, and simulated implementation
- 2024
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Ingår i: Monthly notices of the Royal Astronomical Society. - : Oxford University Press. - 0035-8711 .- 1365-2966. ; 530:3, s. 2688-2730
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Tidskriftsartikel (refereegranskat)abstract
- WEAVE, the new wide-field, massively multiplexed spectroscopic survey facility for the William Herschel Telescope, saw first light in late 2022. WEAVE comprises a new 2-deg field-of-view prime-focus corrector system, a nearly 1000-multiplex fibre positioner, 20 individually deployable 'mini' integral field units (IFUs), and a single large IFU. These fibre systems feed a dual-beam spectrograph covering the wavelength range 366-959nm at R similar to 5000, or two shorter ranges at . After summarizing the design and implementation of WEAVE and its data systems, we present the organization, science drivers, and design of a five- to seven-year programme of eight individual surveys to: (i) study our Galaxy's origins by completing Gaia's phase-space information, providing metallicities to its limiting magnitude for similar to 3 million stars and detailed abundances for similar to 1.5 million brighter field and open-cluster stars; (ii) survey similar to 0.4 million Galactic-plane OBA stars, young stellar objects, and nearby gas to understand the evolution of young stars and their environments; (iii) perform an extensive spectral survey of white dwarfs; (iv) survey similar to 400 neutral-hydrogen-selected galaxies with the IFUs; (v) study properties and kinematics of stellar populations and ionized gas in z < 0.5 cluster galaxies; (vi) survey stellar populations and kinematics in field galaxies at 0.3 less than or similar to z less than or similar to 0.7; (vii) study the cosmic evolution of accretion and star formation using >1 million spectra of LOFAR-selected radio sources; and (viii) trace structures using intergalactic/circumgalactic gas at z > 2. Finally, we describe the WEAVE Operational Rehearsals using the WEAVE Simulator.
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| 2. |
- Merluzzi, A. P., et al.
(författare)
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Neurodegeneration, synaptic dysfunction, and gliosis are phenotypic of Alzheimer dementia
- 2018
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Ingår i: Neurology. - : Ovid Technologies (Wolters Kluwer Health). - 0028-3878 .- 1526-632X. ; 91:5
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Tidskriftsartikel (refereegranskat)abstract
- Objective To test the hypothesis that cognitively unimpaired individuals with Alzheimer disease (AD) neuropathology differ from individuals with AD dementia on biomarkers of neurodegeneration, synaptic dysfunction, and glial activation. In a cross-sectional study, adult participants >70 years old (n = 79, age 77.1 +/- 5.3 years) underwent comprehensive cognitive evaluation and CSF collection, which was assayed for markers of amyloid, phosphorylated tau (p-tau), neurodegeneration (neurofilament light protein [NFL] and total tau), synaptic dysfunction (neurogranin), and glial activation (chiti-nase-3-like protein 1 [YKL-40]). Participants were divided into 3 groups based on diagnosis and p-tau/beta-amyloid42 (A beta 42): those with low p-tau/A beta 42 and unimpaired cognition were classified as controls (n = 25); those with high p-tau/A beta 42 diagnosed with AD-dementia or AD-mild cognitive impairment were classified as AD-Dementia (n = 40); and those with high p-tau/A beta 42 but unimpaired cognition were classified as mismatches (n = 14). A similar, secondary analysis was performed with no age exclusion criteria (n = 411). In both the primary and secondary analyses, biomarker levels between groups were compared with the use of analysis of covariance while controlling for age and demographic variables. Despite p-tau/A beta 42 and A beta 42/A beta 40 levels comparable to those of the AD-Dementia group, mismatches had significantly lower levels of NFL and total tau. While not significantly lower than the AD-Dementia group on YKL-40 and neurogranin, mismatches were also not significantly different from controls. These results provide evidence that, in the absence of significant neurodegenerative processes, individuals who harbor AD neuropathology may remain cognitively unimpaired. This finding provides insight into the biological processes phenotypic of dementia and supports monitoring multiple biomarkers in individuals positive for AD neuropathology.
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| 3. |
- Vogt, N. M., et al.
(författare)
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Gut microbiome alterations in Alzheimer's disease
- 2017
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 7
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Tidskriftsartikel (refereegranskat)abstract
- Alzheimer's disease (AD) is the most common form of dementia. However, the etiopathogenesis of this devastating disease is not fully understood. Recent studies in rodents suggest that alterations in the gut microbiome may contribute to amyloid deposition, yet the microbial communities associated with AD have not been characterized in humans. Towards this end, we characterized the bacterial taxonomic composition of fecal samples from participants with and without a diagnosis of dementia due to AD. Our analyses revealed that the gut microbiome of AD participants has decreased microbial diversity and is compositionally distinct from control age-and sex-matched individuals. We identified phylum-through genus-wide differences in bacterial abundance including decreased Firmicutes, increased Bacteroidetes, and decreased Bifidobacterium in the microbiome of AD participants. Furthermore, we observed correlations between levels of differentially abundant genera and cerebrospinal fluid (CSF) biomarkers of AD. These findings add AD to the growing list of diseases associated with gut microbial alterations, as well as suggest that gut bacterial communities may be a target for therapeutic intervention.
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| 4. |
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| 5. |
- Merluzzi, A. P., et al.
(författare)
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Differential effects of neurodegeneration biomarkers on subclinical cognitive decline
- 2019
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Ingår i: Alzheimer's and Dementia: Translational Research and Clinical Interventions. - : Wiley. - 2352-8737. ; 5, s. 129-138
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Neurodegeneration appears to be the biological mechanism most proximate to cognitive decline in Alzheimer's disease. We test whether t-tau and alternative biomarkers of neurodegeneration—neurogranin and neurofilament light protein (NFL)—add value in predicting subclinical cognitive decline. Methods: One hundred fifty cognitively unimpaired participants received a lumbar puncture for cerebrospinal fluid and at least two neuropsychological examinations (mean age at first visit = 59.3 ± 6.3 years; 67% female). Linear mixed effects models were used with cognitive composite scores as outcomes. Neurodegeneration interactions terms were the primary predictors of interest: age × NFL or age × neurogranin or age × t-tau. Models were compared using likelihood ratio tests. Results: Age × NFL accounted for a significant amount of variation in longitudinal change on preclinical Alzheimer's cognitive composite scores, memory composite scores, and learning scores, whereas age × neurogranin and age × t-tau did not. Discussion: These data suggest that NFL may be more sensitive to subclinical cognitive decline compared to other proposed biomarkers for neurodegeneration. © 2019
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| 6. |
- Merluzzi, S, et al.
(författare)
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CD40 stimulation induces Pax5/BSAP and EBF activation through a APE/ref-1-dependent redox mechanism
- 2004
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Ingår i: Journal of Biological Chemistry. - : American Society for Biochemistry and Molecular Biology. - 0021-9258 .- 1083-351X. ; 279:3, s. 1777-1786
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Tidskriftsartikel (refereegranskat)abstract
- CD40 is a member of the growing tumor necrosis factor receptor family that has been shown to play important roles in T cell-mediated B lymphocyte activation. Ligation of B cell CD40 by CD154, mainly expressed on activated T cells, stimulates B cell proliferation, differentiation, isotype switching, up-regulation of surface molecules contributing to antigen presentation, development of the germinal center, and the humoral memory response. In this study we demonstrate that the redox factor APE/Ref-1 acts as a key signaling intermediate in response to CD40-mediated B cell activation. The transcription factors Pax5a or BSAP ( B cell lineage-specific activator protein) and EBF ( early B cell factor) are constitutively expressed in spleen B cells and CD40 cross-linking induces increases in Pax5a and EBF binding activity compared with nonstimulated B cells. We show that upon CD40 antibody-mediated cross-linking, APE/Ref-1 translocates from the cytoplasm to the nucleus of activated B cells, where it modulates the DNA binding activity of both Pax5a and EBF. Moreover, we show that the repression of APE/Ref-1 protein production is able to block CD40-mediated Pax5a activation. We also provide evidence that APE/Ref-1 can modulate the cooperative activation of the blk promoter operated by Pax5a and EBF and that APE/Ref-1 might directly regulate EBF functional activity. Finally, we show that the interaction between Pax5a and EBF enhances EBF binding activity to its consensus sequence, suggesting that Pax5a can physically interact with EBF and modulate its DNA binding activity.
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