Summary
Background
Dermoscopy improves diagnostic accuracy in melanoma, as shown by several meta‐analyses. Although it is used by general practitioners (GPs) in Australia, Canada and Italy, no ...published data on this topic are available in France.
Objectives
To review the opinions and use of dermoscopy by GPs in France and to understand their practice of skin examination.
Methods
We designed a descriptive and cross‐sectional survey and conducted it between 26 November and 26 December 2014. An anonymous, multiple‐choice questionnaire about the demographic characteristics, skin examination modalities and use and training in dermoscopy was sent to 4057 GPs in four large regions of France. Pearson, χ2, Student, Welch and Fisher tests were used for cross‐tabulation statistical analysis.
Results
Only 8% of respondents had access to a dermoscope; most were male practitioners and aged > 50 years. Dermoscopy increased self‐confidence in analysing pigmented lesions (P = 0·004), and dermoscopy users referred fewer patients to dermatologists. The number of biopsies was reduced in the dermoscopy users group (P = 0·004). In total, 425 questionnaires were returned and analysed. Dermoscopy users took more time to evaluate a single pigmented lesion (P = 0·015). Only 16·9% of physicians declared having received some training on dermoscopy, yet this number reached 47% for those owning a dermoscope. Their training was mostly short and recent. Overall 29·2% of the respondents said the main advantage was to reduce the number of referrals to the dermatologists (P = 0·004), while its main disadvantage was the necessity of training (54·6%). Our responders declared they could spend seven working days on a dermoscopy training course.
Conclusions
Our study demonstrates positive opinions regarding dermoscopy, despite a minority of French GPs using this technique in the areas surveyed. The need for formal training appears to be the main limitation to wider use. Appropriate and specifically designed training programmes should be offered.
What's already known about this topic?
National surveys regarding the use of dermoscopy by general practitioners have been conducted mainly in Australia and Italy.
The use by French general practitioners has never previously been described, despite dermoscopy being a useful tool for the diagnosis of melanoma.
What does this study add?
Dermoscopy provides new and important diagnostic criteria to diagnose melanoma more accurately and reliably.
We report herein the first study evaluating the use of dermoscopy by general practitioners in France.
We aimed to analyse the current use, opinions, teaching modalities and research in this field.
Linked Comment: Rosendahl. Br J Dermatol 2016; 175:673–674.
Plain language summary available online
In this article we prove that Lax pairs associated with ħ-dependent six Painlevé equations satisfy the topological type property proposed by Bergère, Borot and Eynard for any generic choice of the ...monodromy parameters. Consequently we show that one can reconstruct the formal ħ-expansion of the isomonodromic τ-function and of the determinantal formulas by applying the so-called topological recursion to the spectral curve attached to the Lax pair in all six Painlevé cases. Finally we illustrate the former results with the explicit computations of the first orders of the six τ-functions.
The cosmogenic radionuclide 7superscriptBe has been applied as a tracer of dynamical processes in the upper ocean and of atmospheric deposition of trace elements at the sea surface. These ...applications usually assume that 7superscriptBe is entirely in the dissolved form, and that scavenging and downward export of 7superscriptBe by settling particles can be neglected. In this work, we explore these assumptions and more generally assess the significance of the 7superscriptBe activity in the particulate fraction, through the generation of vertical profiles of particulate 7superscriptBe in the open ocean. From detailed measurements obtained from low-background gamma spectrometers placed in underground facilities, we report vertical profiles of 7superscriptBe activity in suspended particles (7superscriptBepsubscript) collected in various oceanic regions: the Mediterranean Sea (DYFAMED station), the Indian Sector of the Southern Ocean (station A3-2 from the KEOPS2 cruise), the Sargasso Sea (OFP station), and the subpolar North Atlantic Ocean (GEOVIDE cruise).
We find that, in each oceanic region, 7superscriptBepsubscript activities are generally higher in the mixed layer than in the thermocline. They vary in the mixed layer from 3.0 dpm/m3 at DYFAMED to 33.1dpm/m3 at GEOVIDE cross-over station 51/60, i.e., within a range consistent with previous 7superscriptBepsubscript measurements for the open ocean. For the GEOVIDE cruise, the 7superscriptBepsubscript activities measured on different filter types at different depths are corrected for filter offsets derived from multiple 7superscriptBepsubscript measurements at a near-coastal station in the western Mediterranean Sea. We then combine measurements of total 7superscriptBe activity (Shelley et al., 2017) with our measurements of 7superscriptBepsubscript activity to estimate the solid/solution partitioning of 7superscriptBe. On average, the particulate fraction would represent 6% of total 7superscriptBe activity at 5-m water depth (n = 6), 22% at 20 m (n = 2) and 9% at 70 m (n = 3). At GEOVIDE stations, 7superscriptBepsubscript inventories range from 5% to 19% of the total 7superscriptBe inventories. In the Labrador Sea, the measured 7superscriptBepsubscript inventories are lower than the dry 7superscriptBe deposition fluxes estimated from aerosol samples collected during GEOVIDE, suggesting that a significant portion of 7superscriptBepsubscript may be removed by sinking particles. The distribution coefficient Kd for 7Be increases with depth, with log10Kd averaging 5.2 ± 0.1 at 5 m to 6.1 ± 0.1 between 70 and 150 m, suggesting that scavenging of dissolved 7superscriptBe by particles is more pronounced in the thermocline than in the mixed layer when differences in particle concentrations are taken into account. Overall, our study suggests that, at least in some oceanic regions, the removal of 7superscriptBe by marine particles may be significant and that it may need to be considered in applications of 7superscriptBe as a tracer of oceanic processes and atmospheric deposition.
A series of sup.14C measurements in Ocean Drilling Program cores from the tropical Cariaco Basin, which have been correlated to the annual-layer counted chronology for the Greenland Ice Sheet Project ...2 (GISP2) ice core, provides a high-resolution calibration of the radiocarbon time scale back to 50,000 years before the present. Independent radiometric dating of events correlated to GISP2 suggests that the calibration is accurate. Reconstructed sup.14C activities varied substantially during the last glacial period, including sharp peaks synchronous with the Laschamp and Hone Lake geomagnetic field intensity minimal and cosmogenic nuclide peaks in ice cores and marine sediments. Simulations with a geochemical box model suggest that much of the variability can be explained by geomagnetically modulated changes in sup.14C production rate together with plausible changes in deep-ocean ventilation and the global carbon cycle during glaciation.
In this short article, we propose a full large
N
asymptotic expansion of the probability that the
m
th
power of a random unitary matrix of size
N
has all its eigenvalues in a given arc-interval ...centered in 1 when
N
is large. This corresponds to the asymptotic expansion of a Toeplitz determinant whose symbol is the indicator function of several intervals having a discrete rotational symmetry. This solves and improves a conjecture left opened by the author in Marchal (Lett Math Phys 110:211–258, 2020). It also provides a rare example of the explicit computation of a full asymptotic expansion of a genus
g
>
0
classical spectral curve, including the oscillating non-perturbative terms, using the topological recursion.
Gaia Data Release 2 Lanzafame, A. C.; Distefano, E.; Messina, S. ...
Astronomy & astrophysics,
08/2018, Letnik:
616
Journal Article
Recenzirano
Odprti dostop
Context. Amongst the ≈5 × 105 sources identified as variable stars in Gaia Data Release 2 (DR2), 26% are rotational modulation variable candidates of the BY Dra class. Gaia DR2 provides their ...multi-band (G, GBP, and GRP) photometric time series collected by the European Space Agency spacecraft Gaia during the first 22 months of operations as well as the essential parameters related to their flux modulation induced by surface inhomogeneities and rotation. Aims. We developed methods to identify the BY Dra variable candidates and to infer their variability parameters. Methods. BY Dra candidates were pre-selected from their position in the Hertzsprung–Russel diagram, built from Gaia parallaxes, G magnitudes, and (GBP − GRP) colours. Since the time evolution of the stellar active region can disrupt the coherence of the signal, segments not much longer than their expected evolution timescale were extracted from the entire photometric time series, and period search algorithms were applied to each segment. For the Gaia DR2, we selected sources with similar periods in at least two segments as candidate BY Dra variables. Results were further filtered considering the time-series phase coverage and the expected approximate light-curve shape. Results. Gaia DR2 includes rotational periods and modulation amplitudes of 147 535 BY Dra candidates. The data unveil the existence of two populations with distinctive period and amplitude distributions. The sample covers 38% of the whole sky when divided into bins (HEALPix) of ≈0.84 square degrees, and we estimate that this represents 0.7–5% of all BY Dra stars potentially detectable with Gaia. Conclusions. The preliminary data contained in Gaia DR2 illustrate the vast and unique information that the mission is going to provide on stellar rotation and magnetic activity. This information, complemented by the exquisite Gaia parallaxes, proper motions, and astrophysical parameters, is opening new and unique perspectives for our understanding of the evolution of stellar angular momentum and dynamo action.
Gaia Data Release 2 Clementini, G.; Ripepi, V.; Molinaro, R. ...
Astronomy & astrophysics,
02/2019, Letnik:
622
Journal Article
Recenzirano
Odprti dostop
Context. The Gaia second Data Release (DR2) presents a first mapping of full-sky RR Lyrae stars and Cepheids observed by the spacecraft during the initial 22 months of science operations. Aims. The ...Specific Objects Study (SOS) pipeline, developed to validate and fully characterise Cepheids and RR Lyrae stars (SOS Cep&RRL) observed by Gaia, has been presented in the documentation and papers accompanying the Gaia first Data Release. Here we describe how the SOS pipeline was modified to allow for processing the Gaia multi-band (G, GBP, and GRP) time-series photometry of all-sky candidate variables and produce specific results for confirmed RR Lyrae stars and Cepheids that are published in the DR2 catalogue. Methods. The SOS Cep&RRL processing uses tools such as the period–amplitude and the period–luminosity relations in the G band. For the analysis of the Gaia DR2 candidates we also used tools based on the GBP and GRP photometry, such as the period–Wesenheit relation in (G, GRP). Results. Multi-band time-series photometry and characterisation by the SOS Cep&RRL pipeline are published in Gaia DR2 for 150 359 such variables (9575 classified as Cepheids and 140 784 as RR Lyrae stars) distributed throughout the sky. The sample includes variables in 87 globular clusters and 14 dwarf galaxies (the Magellanic Clouds, 5 classical and 7 ultra-faint dwarfs). To the best of our knowledge, as of 25 April 2018, the variability of 50 570 of these sources (350 Cepheids and 50 220 RR Lyrae stars) has not been reported before in the literature, therefore they are likely new discoveries by Gaia. An estimate of the interstellar absorption is published for 54 272 fundamental-mode RR Lyrae stars from a relation based on the G-band amplitude and the pulsation period. Metallicities derived from the Fourier parameters of the light curves are also released for 64 932 RR Lyrae stars and 3738 fundamental-mode classical Cepheids with periods shorter than 6.3 days.
PDF
