Observations of distant supernovae indicate that the Universe is now in a phase of accelerated expansion the physical cause of which is a mystery. Formally, this requires the inclusion of a term ...acting as a negative pressure in the equations of cosmic expansion, accounting for about 75 per cent of the total energy density in the Universe. The simplest option for this 'dark energy' corresponds to a 'cosmological constant', perhaps related to the quantum vacuum energy. Physically viable alternatives invoke either the presence of a scalar field with an evolving equation of state, or extensions of general relativity involving higher-order curvature terms or extra dimensions. Although they produce similar expansion rates, different models predict measurable differences in the growth rate of large-scale structure with cosmic time. A fingerprint of this growth is provided by coherent galaxy motions, which introduce a radial anisotropy in the clustering pattern reconstructed by galaxy redshift surveys. Here we report a measurement of this effect at a redshift of 0.8. Using a new survey of more than 10,000 faint galaxies, we measure the anisotropy parameter = 0.70 ± 0.26, which corresponds to a growth rate of structure at that time of f = 0.91 ± 0.36. This is consistent with the standard cosmological-constant model with low matter density and flat geometry, although the error bars are still too large to distinguish among alternative origins for the accelerated expansion. The correct origin could be determined with a further factor-of-ten increase in the sampled volume at similar redshift.
Aims. We present and release photometric redshifts for a uniquely large and deep sample of 522286 objects with $i'_{\rm AB}\le 25$ in the Canada-France Hawaii Telescope Legacy Survey (CFHTLS) “Deep ...Survey” fields D1, D2, D3, and D4, which cover a total effective area of 3.2 $\deg^2$. Methods. We use 3241 spectroscopic redshifts with $0 \leq z \leq 5$ from the VIMOS VLT Deep Survey (VVDS) as a calibration and training set to derive these photometric redshifts. Using the “Le Phare” photometric redshift code, we developed a robust calibration method based on an iterative zero-point refinement combined with a template optimisation procedure and the application of a Bayesian approach. This method removes systematic trends in the photometric redshifts and significantly reduces the fraction of catastrophic errors (by a factor of 2), a significant improvement over traditional methods. We use our unique spectroscopic sample to present a detailed assessment of the robustness of the photometric redshift sample. Results. For a sample selected at $i'_{\rm AB}\le 24$, we reach a redshift accuracy of $\sigma_{\Delta z/(1+z)}=0.029$ with $\eta=3.8\%$ of catastrophic errors (η is defined strictly as those objects with $|\Delta z|/(1+z) > 0.15$). The reliability of our photometric redshifts decreases for faint objects: we find $\sigma_{\Delta z/(1+z)}=0.025, 0.034$ and $\eta=1.9\%, 5.5\%$ for samples selected at $i'_{\rm AB}=17.5$–22.5 and 22.5–24 respectively. We find that the photometric redshifts of starburst galaxies are less reliable: although these galaxies represent only 22% of the spectroscopic sample, they are responsible for 50% of the catastrophic errors. An analysis as a function of redshift demonstrates that our photometric redshifts work best in the redshift range $0.2\le z \le 1.5$. We find an excellent agreement between the photometric and the VVDS spectroscopic redshift distributions at $i'_{\rm AB}\le 24$. Finally, we compare the redshift distributions of i' selected galaxies on the four CFHTLS deep fields, showing that cosmic variance is still present on fields of 0.7–0.9 deg2. These photometric redshifts are made publicly available at http://terapix.iap.fr (complete ascii catalogues) and http://cencos.oamp.fr/cencos/CFHTLS/ (searchable database interface).
Background
Hereditary angioedema with C1 inhibitor deficiency (C1‐INH‐HAE) is a rare inherited genetic disease characterized by recurrent swelling episodes of the skin, gastrointestinal tract, and ...upper airways. Angioedema attacks result from increased vascular permeability due to the release of bradykinin from high molecular weight kininogen. Currently, there are no biomarkers predicting the frequency of angioedema attacks. Vascular permeability is modulated by several factors, including vascular endothelial growth factors (VEGFs) and angiopoietins (Angs). As increased circulating levels of VEGFs and Angs have been observed in diseases associated with higher vascular permeability (e.g., systemic capillary leak syndrome and sepsis), we sought to analyze plasma concentrations of VEGFs and Angs in patients with C1‐INH‐HAE.
Methods
Sixty‐eight healthy controls and 128 patients with C1‐INH‐HAE were studied. Concentrations of angiogenic (VEGF‐A, Ang1, Ang2), anti‐angiogenic (VEGF‐A165b) and lymphangiogenic (VEGF‐C) factors were evaluated by ELISA. C1‐INH functional activity was assessed by EIA.
Results
Plasma concentrations of VEGF‐A, VEGF‐C, Ang1, and Ang2 were higher in patients with C1‐INH‐HAE in remission than in healthy controls. Concentration of VEGF‐A was further increased in patients with lower C1‐INH functional activity. Patients with C1‐INH‐HAE experiencing more than 12 angioedema attacks per year were characterized by higher plasma levels of VEGF‐A, VEGF‐C, and Ang2 compared with the other patients.
Conclusions
We hypothesize that VEGFs and Angs induce a state of ‘vascular preconditioning’ that may predispose to angioedema attacks. In addition, the identification of increased plasma levels of VEGFs and Angs in patients with C1‐INH‐HAE may prompt the investigation of VEGFs and Angs as biomarkers of C1‐INH‐HAE severity.
Aims. The aim of this work is to identify He II emitters at 2 < z < 4.6 and to constrain the source of the hard ionizing continuum that powers the He II emission. Methods. We assembled a sample of ...277 galaxies with a highly reliable spectroscopic redshift at 2 < z < 4.6 from the VIMOS-VLT Deep Survey (VVDS) Deep and Ultra-Deep data, and we identified 39 He II λ1640 emitters. We studied their spectral properties, measuring the fluxes, equivalent widths (EW), and full width at half maximum (FWHM) for most relevant lines, including He II λ1640, Lyα line, Si II λ1527, and C IV λ1549. Results. About 10% of galaxies at z ~ 3 and iAB ≤ 24.75 show He II in emission, with rest frame equivalent widths EW0 ~ 1–7 Å, equally distributed between galaxies with Lyα in emission or in absorption. We find 11 (3.9% of the global population) reliable He II emitters with unresolved He II lines (FWHM0 < 1200 km s-1), 13 (4.6% of the global population) reliable emitters with broad He II emission (FWHM0 > 1200 km s-1), 3 active galactic nuclei (AGN), and an additional 12 possible He II emitters. The properties of the individual broad emitters are in agreement with expectations from a Wolf-Rayet (W-R) model. Instead, the properties of the narrow emitters are not compatible with this model, nor with predictions of gravitational cooling radiation produced by gas accretion, unless this is severely underestimated by current models by more than two orders of magnitude. Rather, we find that the EW of the narrow He II line emitters are in agreement with expectations for a Population III (PopIII) star formation, if the episode of star formation is continuous, and we calculate that a PopIII star formation rate (SFR) of 0.1–10 M⊙ yr-1 alone is enough to sustain the observed He II flux. Conclusions. We conclude that narrow He II emitters are powered either by the ionizing flux from a stellar population rare at z ~ 0 but much more common at z ~ 3, or by PopIII star formation. As proposed by Tornatore and collaborators, incomplete interstellar medium mixing may leave some small pockets of pristine gas at the periphery of galaxies from which PopIII may form, even down to z ~ 2 or lower. If this interpretation is correct, we measure at z ~ 3 a star formation rate density in PopIII stars of 10-6 M⊙ yr-1 Mpc-3, higher than, but qualitatively comparable to the value predicted by Tornatore and collaborators.
The myriad applicability of the frequency‐domain critical plane criterion is outlined in order to evaluate and track the progression of fatigue damage in metallic structures subjected to high‐cycle ...multiaxial random vibrations. The fatigue assessment using the given criterion is performed according to the following stages: (i) critical plane definition, (ii) power spectral density evaluation of an equivalent normal stress and (iii) computation of the damage precursor and fatigue life.
The frequency‐domain critical plane criterion is validated using experimental results related to (a) AISI 1095 steel cantilever beams under nonlinear base vibration, (b) 18G2A steel and (c) 10HNAP steel round specimens under random non‐proportional combined flexural and torsional loads.
Acquired deficiency of C1 inhibitor (C1-INH) with angioedema symptoms (acquired angioedema, AAE) is characterized by local increase in vascular permeability (angioedema) of the skin and the ...gastrointestinal and oro-pharyngo-laryngeal mucosa. The mediator of symptoms is bradykinin, a potent vasoactive peptide, released from high molecular weight kininogen when it is cleaved by plasma kallikrein a serine protease controlled by C1-INH. Autoantibodies inactivating C1-INH are detected in the majority of patients and account for the deficiency. Irrespectively to the presence of anti-C1-INH autoantibodies lymphoproliferative diseases, ranging from benign monoclonal gammopathies to malignant lymphoma, are frequently associated with AAE. Demonstration that monoclonal components correspond to anti-C1-INH autoantibodies and correlation between course of lymphoma and course of AAE provide strong support to consider the two diseases expression of the same pathologic process.
In addition to complement, we measured plasma levels of F1 + 2 and D-dimer in 28 patients with C1-INH deficiency during acute attacks and remission, 35 patients without C1-INH deficiency during ...abdominal colics, and 20 healthy subjects.
Flaring water masers associated with W49N Volvach, L. N.; Volvach, A. E.; Larionov, M. G. ...
Astronomy and astrophysics (Berlin),
08/2019, Letnik:
628
Journal Article
Recenzirano
Odprti dostop
Aims. We present our monitoring observations and analysis of water masers associated with W49N taken in 2017 and 2018. A significant flare occurred during these observations. Methods. We used ...ground-based radio telescopes in Simeiz (RT-22), Torun (RT-32), Medicina (RT-32), Effelsberg (RT-100) with broadband spectrometers. Observational data were collected and processed automatically. Results. We report a powerful flare of the v = +6 km s−1 water maser feature; it increased in over ten months to S1.3 cm = 84 kJy in 2017 December, then decayed to the pre-flare quiescent value of S1.3 cm = 8.7 kJy in 2018 August. We infer that this flaring feature is unsaturated based on the relationship between line width and flux density.
We explore the accuracy of the clustering-based redshift estimation proposed by Ménard et al. when applied to VIMOS Public Extragalactic Redshift Survey (VIPERS) and Canada–France–Hawaii Telescope ...Legacy Survey (CFHTLS) real data. This method enables us to reconstruct redshift distributions from measurement of the angular clustering of objects using a set of secure spectroscopic redshifts. We use state-of-the-art spectroscopic measurements with i
AB < 22.5 from the VIPERS as reference population to infer the redshift distribution of galaxies from the CFHTLS T0007 release. VIPERS provides a nearly representative sample to a flux limit of i
AB < 22.5 at a redshift of >0.5 which allows us to test the accuracy of the clustering-based redshift distributions. We show that this method enables us to reproduce the true mean colour–redshift relation when both populations have the same magnitude limit. We also show that this technique allows the inference of redshift distributions for a population fainter than the reference and we give an estimate of the colour–redshift mapping in this case. This last point is of great interest for future large-redshift surveys which require a complete faint spectroscopic sample.
Summary
Background
Hereditary angioedema (HAE) owing to C1 inhibitor deficiency is an autosomal dominant disorder, characterized by recurrent, potentially life‐threatening, localized attacks of ...tissue swelling. Current treatment involves the infusion of C1 inhibitor protein (C1‐INH) isolated from human plasma.
Objectives
This open‐label extension to a European, Israeli and Argentinean randomized study (NCT00262301) aimed to investigate the efficacy and safety of recombinant human C1 inhibitor (rhC1‐INH) as a first‐line treatment following an HAE attack, together with its effect on subsequent attacks.
Methods
An HAE‐specific visual analogue scale (VAS) 0–100 mm was used by patients to assess the severity of attack at four anatomical locations. Patients were treated with one, single‐vial, fixed‐dose of rhC1‐INH (2100 U), followed by up to two further vials at the investigators discretion. The primary end‐point was the time from first rhC1‐INH injection to first onset of relief of symptoms (≥ 20 mm decrease on VAS). Response to treatment was defined as the onset of relief within 4 h.
Results
A total of 57 patients were treated for 194 HAE attacks. Overall, sustained relief of symptoms was achieved in 87% of rhC1‐INH‐treated patients within 4 h of treatment, with 57% of attacks requiring only one vial of rhC1‐INH. When categorized by successive attacks experienced by individual patients, the response rate to rhC1‐INH treatment was 96%, 83%, 87%, 80% and 80% for attacks 1–5 respectively. Treatment with rhC1‐INH was well tolerated, with no discontinuations owing to treatment‐emergent adverse events and no adverse events relating to immunogenicity.
Conclusions and Clinical Relevance
Treatment with rhC1‐INH provides fast‐onset relief for an HAE attack, with a high rate of therapeutic response maintained throughout subsequent attacks.
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