A global Carleman estimate in a transmission wave equation and application to a one-measurement inverse problem

We consider a transmission wave equation in two embedded domains in $R^2$, where the speed is $a1 > 0$ in the inner domain and $a2 > 0$ in the outer domain. We prove a global Carleman inequality for this problem under the hypothesis that the inner domain is strictly convex and $a1 > a2$ . As a consequence of this inequality, uniqueness and Lip- schitz stability are obtained for the inverse problem of retrieving a stationary potential for the wave equation with Dirichlet data and discontinuous principal coefficient from a single time-dependent Neumann boundary measurement

Long-term variability of the optical spectra of NGC 4151: I. Light curves and flux correlations

Results of a long-term spectral monitoring of the active galactic nucleus of NGC 4151 are presented (11 years, from 1996 to 2006). High quality spectra (S/N>50 in the continuum near Halpha and Hbeta) were obtained in the spectral range ~4000 to 7500 \AA, with a resolution between 5 and 15 A, using the 6-m and the 1-m SAO's telescopes (Russia), the GHAO's 2.1-m telescope (Cananea, Mexico), and the OAN-SPM's 2.1-m telescope (San-Pedro, Mexico). The observed fluxes of the Halpha, Hbeta, Hgamma and HeII emission lines and of the continuum at the observed wavelength 5117 A, were corrected for the position angle, the seeing and the aperture effects. We found that the continuum and line fluxes varied strongly (up to a factor 6) during the monitoring period. The emission was maximum in 1996-1998, and there were two minima, in 2001 and in 2005. The Halpha, Hgamma and He II fluxes were well correlated with the Hbeta flux. We considered three characteristic periods during which the Hbeta and Halpha profiles were similar: 1996-1999, 2000-2001 and 2002-2006. The line to continuum flux ratios were different; in particular during the first period, the lines were not correlated with the continuum and saturated at high fluxes. In the second and third period, where the continuum flux was small, the Halpha and Hbeta fluxes were well correlated to the continuum flux, meaning that the ionizing continuum was a good extrapolation of the optical continuum. The CCFs are often asymmetrical and the time lags between the lines and the continuum are badly defined indicating the presence of a complex BLR, with dimensions from 1 to 50 light-days.Comment: A&A, accepte

Spectral Optical Monitoring of the Narrow Line Seyfert 1 galaxy Ark 564

We present the results of a long-term (1999--2010) spectral optical monitoring campaign of the active galactic nucleus (AGN) Ark 564, which shows a strong Fe II line emission in the optical. This AGN is a narrow line Seyfert 1 (NLS1) galaxies, a group of AGNs with specific spectral characteristics. We analyze the light curves of the permitted Ha, Hb, optical Fe II line fluxes, and the continuum flux in order to search for a time lag between them. Additionally, in order to estimate the contribution of iron lines from different multiplets, we fit the Hb and Fe II lines with a sum of Gaussian components. We found that during the monitoring period the spectral variation (F_max/F_min) of Ark 564 was between 1.5 for Ha to 1.8 for the Fe II lines. The correlation between the Fe II and Hb flux variations is of higher significance than that of Ha and Hb (whose correlation is almost absent). The permitted-line profiles are Lorentzian-like, and did not change shape during the monitoring period. We investigated, in detail, the optical Fe II emission and found different degrees of correlation between the Fe II emission arising from different spectral multiplets and the continuum flux. The relatively weak and different degrees of correlations between permitted lines and continuum fluxes indicate a rather complex source of ionization of the broad line emission region.Comment: Accepted for publication in ApJ

Clinicians' perspectives on supporting individuals with severe anorexia nervosa in specialist eating disorder intensive treatment settings

BACKGROUND: Admissions to intensive treatment (i.e., inpatient [IP] and/or day patient [DP]) for individuals with severe anorexia nervosa (AN) are common. Growing literature indicates potential risks and benefits of each intensive treatment approach; however, existing research has focused on patient and carer perspectives of these treatments. Also, there is scant empirical evidence available for guiding the parameters of intensive treatments for AN. We therefore explored clinicians' perspectives and experience of supporting adults with severe AN in intensive settings. METHODS: We conducted twenty one semi-structured interviews with clinicians who deliver intensive treatments (i.e., IP and/or DP) for individuals with severe AN across four specialist Eating Disorder Services in the United Kingdom between May 2020 and June 2021. We asked clinicians about their views and experiences of supporting individuals with severe AN in intensive treatment settings and the challenges and opportunities associated with IP and DP treatment. Data were analysed using reflexive thematic analysis supported by NVivo software. RESULTS: Five broad and interrelated themes were identified: (1) Intensive Support; (2) The Severity of Patients' Illnesses; (3) Hope and Recovery; (4) Which Treatment When; (5) Limited Resources; and (6) Carer Burden. We identified various similarities between the two intensive treatment approaches, including the value of intensive and multidisciplinary support and carer involvement, and the challenge of managing complex and unique needs in resource-limited intensive settings. We also found differences in the relationship of treatment to patients' home environments, the necessity of patient motivation, and the management of risk. CONCLUSIONS: Both intensive treatment settings are valued by clinicians; however, there are unique challenges and opportunities for supporting individuals with severe AN within each. Our findings suggest DP treatment may be used as an alternative to IP treatment for individuals with severe AN. However, clear questions remain over which intensive treatment setting is best suited to which patient when and should be the focus of future research

Autopsy of a failed trial part 1: A qualitative investigation of clinician's views on and experiences of the implementation of the DAISIES trial in UK-based intensive eating disorder services

Objective: The DAISIES trial, comparing inpatient and stepped-care day patient treatment for adults with severe anorexia nervosa was prematurely terminated in March 2022 due to poor recruitment. This qualitative study seeks to understand the difficulties faced during the trial by investigating stakeholders' views on and experiences of its implementation. / Method: Semi-structured interview and focus group transcripts, and trial management and oversight group meeting minutes from May 2020-June 2022 were analysed using thematic analysis. Participants were 47 clinicians and co-investigators involved with the DAISIES trial. The Non-Adoption, Abandonment, Scale-up, Spread, and Sustainability (NASSS) framework was applied to the interpretive themes to classify barriers and facilitators to implementation. / Results: Five themes were identified: incompatible participation interests; changing standard practice; concerns around clinical management; systemic capacity and capability issues; and Covid-19 disrupting implementation. Applying the NASSS framework indicated the greatest implementation challenges to arise with the adopters (e.g. patients, clinicians), the organisational systems (e.g. service capacity), and the wider socio-political context (e.g. Covid-19 closing services). / Conclusions: Our findings emphasise the top-down impact of systemic-level research implementation challenges. The impact of the Covid-19 pandemic accentuated pre-existing organisational barriers to trial implementation within intensive eating disorder services, further limiting the capacity for research

Modelling the radiative effects of biomass burning aerosols on carbon fluxes in the Amazon region

Every year, a dense smoke haze covers a large portion of South America originating from fires in the Amazon Basin and central parts of Brazil during the dry biomass burning season between August and October. Over a large portion of South America, the average aerosol optical depth at 550 nm exceeds 1.0 during the fire season, while the background value during the rainy season is below 0.2. Biomass burning aerosol particles increase scattering and absorption of the incident solar radiation. The regional-scale aerosol layer reduces the amount of solar energy reaching the surface, cools the near-surface air, and increases the diffuse radiation fraction over a large disturbed area of the Amazon rainforest. These factors affect the energy and CO2 fluxes at the surface. In this work, we applied a fully integrated atmospheric model to assess the impact of biomass burning aerosols in CO2 fluxes in the Amazon region during 2010. We address the effects of the attenuation of global solar radiation and the enhancement of the diffuse solar radiation flux inside the vegetation canopy. Our results indicate that biomass burning aerosols led to increases of about 27 % in the gross primary productivity of Amazonia and 10 % in plant respiration as well as a decline in soil respiration of 3 %. Consequently, in our model Amazonia became a net carbon sink; net ecosystem exchange during September 2010 dropped from +101 to −104 TgC when the aerosol effects are considered, mainly due to the aerosol diffuse radiation effect. For the forest biome, our results point to a dominance of the diffuse radiation effect on CO2 fluxes, reaching a balance of 50–50 % between the diffuse and direct aerosol effects for high aerosol loads. For C3 grasses and savanna (cerrado), as expected, the contribution of the diffuse radiation effect is much lower, tending to zero with the increase in aerosol load. Taking all biomes together, our model shows the Amazon during the dry season, in the presence of high biomass burning aerosol loads, changing from being a source to being a sink of CO2 to the atmosphere

Measurement of the Neutron Radius of 208Pb Through Parity-Violation in Electron Scattering

We report the first measurement of the parity-violating asymmetry A_PV in the elastic scattering of polarized electrons from 208Pb. A_PV is sensitive to the radius of the neutron distribution (Rn). The result A_PV = 0.656 \pm 0.060 (stat) \pm 0.014 (syst) ppm corresponds to a difference between the radii of the neutron and proton distributions Rn - Rp = 0.33 +0.16 -0.18 fm and provides the first electroweak observation of the neutron skin which is expected in a heavy, neutron-rich nucleus.Comment: 6 pages, 1 figur

Spectral optical monitoring of 3C390.3 in 1995-2007: I. Light curves and flux variation of the continuum and broad lines

Here we present the results of the long-term (1995-2007) spectral monitoring of the broad line radio galaxy \object{3C~390.3}, a well known AGN with the double peaked broad emission lines, usually assumed to be emitted from an accretion disk. To explore dimensions and structure of the BLR, we analyze the light curves of the broad H$\alpha$ and H$\beta$ line fluxes and the continuum flux. In order to find changes in the BLR, we analyze the H$\alpha$ and H$\beta$ line profiles, as well as the change in the line profiles during the monitoring period. First we try to find a periodicity in the continuum and H$\beta$ light curves, finding that there is a good chance for quasi-periodical oscillations. Using the line shapes and their characteristics (as e.g. peaks separation and their intensity ratio, or FWHM) of broad H$\beta$ and H$\alpha$ lines, we discuss the structure of the BLR. Also, we cross-correlate the continuum flux with H$\beta$ and H$\alpha$ lines to find dimensions of the BLR. We found that during the monitoring period the broad emission component of the H$\alpha$ and H$\beta$ lines, and the continuum flux varied by a factor of $\approx$4-5. Also, we detected different structure in the line profiles of H$\alpha$ and H$\beta$. It seems that an additional central component is present and superposed to the disk emission. In the period of high activity (after 2002), H$\beta$ became broader than H$\alpha$ and red wing of H$\beta$ was higher than the one of H$\alpha$. We found time lags of $\sim$95 days between the continuum and H$\beta$ flux, and about 120 days between the continuum and H$\alpha$ flux. Variation in the line profiles, as well as correlation between the line and continuum flux during the monitoring period is in the favor of the disk origin of the broad lines with the possible contribution of some additional region and/or some kind of perturbation in the disk.Comment: 32 pages, accepted to A&A, typos correcte

Charge separation relative to the reaction plane in Pb-Pb collisions at sNN=2.76\sqrt{s_{\rm NN}}= 2.76 TeV

Measurements of charge dependent azimuthal correlations with the ALICE detector at the LHC are reported for Pb-Pb collisions at $\sqrt{s_{\rm NN}} = 2.76$ TeV. Two- and three-particle charge-dependent azimuthal correlations in the pseudo-rapidity range $|\eta| < 0.8$ are presented as a function of the collision centrality, particle separation in pseudo-rapidity, and transverse momentum. A clear signal compatible with a charge-dependent separation relative to the reaction plane is observed, which shows little or no collision energy dependence when compared to measurements at RHIC energies. This provides a new insight for understanding the nature of the charge dependent azimuthal correlations observed at RHIC and LHC energies.Comment: 12 pages, 3 captioned figures, authors from page 2 to 6, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/286