347 research outputs found

    Magnetism, Critical Fluctuations and Susceptibility Renormalization in Pd

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    Some of the most popular ways to treat quantum critical materials, that is, materials close to a magnetic instability, are based on the Landau functional. The central quantity of such approaches is the average magnitude of spin fluctuations, which is very difficult to measure experimentally or compute directly from the first principles. We calculate the parameters of the Landau functional for Pd and use these to connect the critical fluctuations beyond the local-density approximation and the band structure.Comment: Replaced with the revised version accepted for publication. References updated, errors corrected, other change

    The atmospheric parameters and spectral interpolator for the stars of MILES

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    Context. Empirical libraries of stellar spectra are used for stellar classification and synthesis of stellar populations. MILES is a medium spectral-resolution library in the optical domain covering a wide range of temperatures, surface gravities and metallicities. Aims. We re-determine the atmospheric parameters of these stars in order to improve the homogeneity and accuracy. We build an interpolating function that returns a spectrum as a function of the three atmospheric parameters, and finally, we characterize the precision of the wavelength calibration and stability of the spectral resolution. Methods. We use the ULySS program with the ELODIE library as a reference and compare the results with literature compilations. Results. We obtain precisions of 60 K, 0.13 and 0.05 dex respectively for Teff, log g and [Fe/H] for the FGK stars. For the M stars, the mean errors are 38 K, 0.26 and 0.12 dex, and for the OBA 3.5%, 0.17 and 0.13 dex. We construct an interpolator that we test against the MILES stars themselves. We test it also by measuring the atmospheric parameters of the CFLIB stars with MILES as reference and find it to be more reliable than the ELODIE interpolator for the evolved hot stars, like in particular those of the blue horizontal branch.Comment: A&A accepted, 29 pages, 6 figure

    Clustering of the AKARI NEP deep field 24<i>μ</i>m selected galaxies

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    Aims. We present a method of selection of 24 μm galaxies from the AKARI north ecliptic pole (NEP) deep field down to 150 μJy and measurements of their two-point correlation function. We aim to associate various 24 μm selected galaxy populations with present day galaxies and to investigate the impact of their environment on the direction of their subsequent evolution. Methods. We discuss using of Support Vector Machines (SVM) algorithm applied to infrared photometric data to perform star-galaxy separation, in which we achieve an accuracy higher than 80%. The photometric redshift information, obtained through the CIGALE code, is used to explore the redshift dependence of the correlation function parameter (r0) as well as the linear bias evolution. This parameter relates galaxy distribution to the one of the underlying dark matter. We connect the investigated sources to their potential local descendants through a simplified model of the clustering evolution without interactions. Results. We observe two different populations of star-forming galaxies, at zmed ∼ 0.25, zmed ∼ 0.9. Measurements of total infrared luminosities (LTIR) show that the sample at zmed ∼ 0.25 is composed mostly of local star-forming galaxies, while the sample at zmed ∼ 0.9 is composed of luminous infrared galaxies (LIRGs) with LTIR ∼ 1011.62 L⨀. We find that dark halo mass is not necessarily correlated with the LTIR: for subsamples with LTIR = 1011.15 L⨀ at zmed ∼ 0.7 we observe a higher clustering length (r0 = 6.21 ± 0.78 [h−1Mpc]) than for a subsample with mean LTIR = 1011.84 L⨀ at zmed ∼ 1.1 (r0 = 5.86 ± 0.69 h−1Mpc). We find that galaxies at zmed ∼ 0.9 can be ancestors of present day L∗ early type galaxies, which exhibit a very high r0 ∼ 8h−1 Mpc.</p

    A novel class of microRNA-recognition elements that function only within open reading frames.

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    MicroRNAs (miRNAs) are well known to target 3' untranslated regions (3' UTRs) in mRNAs, thereby silencing gene expression at the post-transcriptional level. Multiple reports have also indicated the ability of miRNAs to target protein-coding sequences (CDS); however, miRNAs have been generally believed to function through similar mechanisms regardless of the locations of their sites of action. Here, we report a class of miRNA-recognition elements (MREs) that function exclusively in CDS regions. Through functional and mechanistic characterization of these 'unusual' MREs, we demonstrate that CDS-targeted miRNAs require extensive base-pairing at the 3' side rather than the 5' seed; cause gene silencing in an Argonaute-dependent but GW182-independent manner; and repress translation by inducing transient ribosome stalling instead of mRNA destabilization. These findings reveal distinct mechanisms and functional consequences of miRNAs that target CDS versus the 3' UTR and suggest that CDS-targeted miRNAs may use a translational quality-control-related mechanism to regulate translation in mammalian cells

    Classification of temporomandibular joint sounds based upon their reduced interference distribution

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    Temporomandibular joint (TMJ) sounds were recorded in 98 orthodontic retention patients, mean age 19 ± 8–6 (s.d.) years, by interview, auscultation and electronic recording. Sounds were found by auscultation in 41% and by interview in 32% of the subjects, more often in females than in males (P ≤ 0.05). A new method for time-frequency analysis, the reduced interference distribution (RID), was used to classify the electronic sound recordings into five subclasses, RID types 1–5, based upon location and number of their energy peaks. RID types 1–3 had a few energy peaks close in time. RID types 4–5, typical of subjects with crepitation, had multiple energy peaks occurring close in time for a period of 20–300 ms. RID type 1, found in 45% of the subjects, typical of patients with clicking, had its dominant energy peak located in a frequency range ≤600 Hz and was significantly more common in the female than in the male subjects (P≤ 0.01). RID type 2, found in 68% of the subjects, with the dominant peak in the range 600–1200 Hz, and RID type 3, found in 38% of the subjects, with the peak in the frequency range >1200 Hz, were found to have a similar gender distribution. RID type 4, found in 49% of the subjects, had the energy peaks distributed in the frequency range ≤600 Hz. RID type 5, found in 43% of the subjects, more often in females than in males (P≤ 0.05), had the peaks distributed over the whole frequency range from about 30 Hz up to about 3000 Hz. In conclusion, a more detailed classification could be made of the TMJ sounds by displaying the RIDs than by auscultation. This suggests that RID classification methods may provide a means for differentiating sounds indicating different types of pathology.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/74694/1/j.1365-2842.1996.tb00809.x.pd

    Multimodal memory T cell profiling identifies a reduction in a polyfunctional Th17 state associated with tuberculosis progression

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    Mycobacterium tuberculosis (M.tb) results in 10 million active tuberculosis (TB) cases and 1.5 million deaths each year, making it the world's leading infectious cause of death. Infection leads to either an asymptomatic latent state or TB disease. Memory T cells have been implicated in TB disease progression, but the specific cell states involved have not yet been delineated because of the limited scope of traditional profiling strategies. Furthermore, immune activation during infection confounds underlying differences in T cell state distributions that influence risk of progression. Here, we used a multimodal single-cell approach to integrate measurements of transcripts and 30 functionally relevant surface proteins to comprehensively define the memory T cell landscape at steady state (i.e., outside of active infection). We profiled 500,000 memory T cells from 259 Peruvians > 4.7 years after they had either latent M.tb infection or active disease and defined 31 distinct memory T cell states, including a CD4+CD26+CD161+CCR6+ effector memory state that was significantly reduced in patients who had developed active TB (OR = 0.80, 95% CI: 0.73-0.87, p = 1.21 x 10-6). This state was also polyfunctional; in ex vivo stimulation, it was enriched for IL-17 and IL-22 production, consistent with a Th17-skewed phenotype, but also had more capacity to produce IFNgamma than other CD161+CCR6+ Th17 cells. Additionally, in progressors, IL-17 and IL-22 production in this cell state was significantly lower than in non-progressors. Reduced abundance and function of this state may be an important factor in failure to control M.tb infection. ### Competing Interest Statement The authors have declared no competing interest
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