ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Publication Date: 2013-03-02
    Description: We simultaneously constrain cosmology and galaxy bias using measurements of galaxy abundances, galaxy clustering and galaxy–galaxy lensing taken from the Sloan Digital Sky Survey. We use the conditional luminosity function (which describes the halo occupation statistics as a function of galaxy luminosity) combined with the halo model (which describes the non-linear matter field in terms of its halo building blocks) to describe the galaxy–dark matter connection. We explicitly account for residual redshift-space distortions in the projected galaxy–galaxy correlation functions, and marginalize over uncertainties in the scale dependence of the halo bias and the detailed structure of dark matter haloes. Under the assumption of a spatially flat, vanilla cold dark matter (CDM) cosmology, we focus on constraining the matter density, m , and the normalization of the matter power spectrum, 8 , and we adopt 7-year Wilkinson Microwave Anisotropy Probe ( WMAP 7) priors for the spectral index, n , the Hubble parameter, h , and the baryon density, b . We obtain that m = 0.278 + 0.023 – 0.026 and 8 = 0.763 + 0.064 – 0.049 (95 per cent CL). These results are robust to uncertainties in the radial number density distribution of satellite galaxies, while allowing for non-Poisson satellite occupation distributions results in a slightly lower value for 8 (0.744 + 0.056 – 0.047 ). These constraints are in excellent agreement (at the 1 level) with the cosmic microwave background constraints from WMAP . This demonstrates that the use of a realistic and accurate model for galaxy bias, down to the smallest non-linear scales currently observed in galaxy surveys, leads to results perfectly consistent with the vanilla CDM cosmology.
    Print ISSN: 0035-8711
    Electronic ISSN: 1365-2966
    Topics: Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Publication Date: 2010-06-22
    Description: The molecular clock maintains energy constancy by producing circadian oscillations of rate-limiting enzymes involved in tissue metabolism across the day and night. During periods of feeding, pancreatic islets secrete insulin to maintain glucose homeostasis, and although rhythmic control of insulin release is recognized to be dysregulated in humans with diabetes, it is not known how the circadian clock may affect this process. Here we show that pancreatic islets possess self-sustained circadian gene and protein oscillations of the transcription factors CLOCK and BMAL1. The phase of oscillation of islet genes involved in growth, glucose metabolism and insulin signalling is delayed in circadian mutant mice, and both Clock and Bmal1 (also called Arntl) mutants show impaired glucose tolerance, reduced insulin secretion and defects in size and proliferation of pancreatic islets that worsen with age. Clock disruption leads to transcriptome-wide alterations in the expression of islet genes involved in growth, survival and synaptic vesicle assembly. Notably, conditional ablation of the pancreatic clock causes diabetes mellitus due to defective beta-cell function at the very latest stage of stimulus-secretion coupling. These results demonstrate a role for the beta-cell clock in coordinating insulin secretion with the sleep-wake cycle, and reveal that ablation of the pancreatic clock can trigger the onset of diabetes mellitus.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2920067/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2920067/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Marcheva, Biliana -- Ramsey, Kathryn Moynihan -- Buhr, Ethan D -- Kobayashi, Yumiko -- Su, Hong -- Ko, Caroline H -- Ivanova, Ganka -- Omura, Chiaki -- Mo, Shelley -- Vitaterna, Martha H -- Lopez, James P -- Philipson, Louis H -- Bradfield, Christopher A -- Crosby, Seth D -- JeBailey, Lellean -- Wang, Xiaozhong -- Takahashi, Joseph S -- Bass, Joseph -- P01 AG011412/AG/NIA NIH HHS/ -- P01 AG011412-080011/AG/NIA NIH HHS/ -- R01 HL097817/HL/NHLBI NIH HHS/ -- R01 HL097817-01/HL/NHLBI NIH HHS/ -- R37 ES005703/ES/NIEHS NIH HHS/ -- R37-ES-005703/ES/NIEHS NIH HHS/ -- Howard Hughes Medical Institute/ -- England -- Nature. 2010 Jul 29;466(7306):627-31. doi: 10.1038/nature09253.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/20562852" target="_blank"〉PubMed〈/a〉
    Keywords: ARNTL Transcription Factors/deficiency/*genetics/metabolism ; Aging/genetics/pathology ; Animals ; Blood Glucose/analysis/metabolism ; CLOCK Proteins/deficiency/*genetics/metabolism ; Cell Proliferation ; Cell Size ; Cell Survival ; Circadian Rhythm/genetics/*physiology ; Diabetes Mellitus/genetics/*metabolism ; Gene Expression Profiling ; Glucose Intolerance/genetics ; Glucose Tolerance Test ; In Vitro Techniques ; Insulin/*blood/metabolism/secretion ; Islets of Langerhans/*metabolism/pathology/secretion ; Mice ; Period Circadian Proteins/genetics/metabolism ; Phenotype ; Sleep/genetics/physiology ; Synaptic Vesicles/metabolism ; Wakefulness/genetics/physiology
    Print ISSN: 0028-0836
    Electronic ISSN: 1476-4687
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Publication Date: 2014-03-01
    Description: We use ROSAT All Sky Survey broad-band X-ray images and the optical clusters identified from Sloan Digital Sky Survey Data Release 7 to estimate the X-ray luminosities around ~65 000 candidate clusters with masses 10 13 h – 1 M based on an optical to X-ray ( otx ) code we develop. We obtain a catalogue with X-ray luminosity for each cluster. This catalogue contains 817 clusters (473 at redshift z ≤ 0.12) with signal-to-noise ratio 〉3 in X-ray detection. We find about 65 per cent of these X-ray clusters have their most massive member located near the X-ray flux peak; for the rest 35 per cent, the most massive galaxy is separated from the X-ray peak, with the separation following a distribution expected from a Navarro–Frenk–White profile. We investigate a number of correlations between the optical and X-ray properties of these X-ray clusters, and find that the cluster X-ray luminosity is correlated with the stellar mass (luminosity) of the clusters, as well as with the stellar mass (luminosity) of the central galaxy and the mass of the halo, but the scatter in these correlations is large. Comparing the properties of X-ray clusters of similar halo masses but having different X-ray luminosities, we find that massive haloes with masses 10 14 h – 1 M contain a larger fraction of red satellite galaxies when they are brighter in X-ray. An opposite trend is found in central galaxies in relative low-mass haloes with masses 10 14 h – 1 M where X-ray brighter clusters have smaller fraction of red central galaxies. Clusters with masses 10 14 h – 1 M that are strong X-ray emitters contain many more low-mass satellite galaxies than weak X-ray emitters. These results are also confirmed by checking X-ray clusters of similar X-ray luminosities but having different characteristic stellar masses. A cluster catalogue containing the optical properties of member galaxies and the X-ray luminosity is available at http://gax.shao.ac.cn/data/Group.html .
    Print ISSN: 0035-8711
    Electronic ISSN: 1365-2966
    Topics: Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...