Spherical parameterization for genus zero surfaces using Laplace-Beltrami eigenfunctions

International audienceIn this work, we propose a fast and simple approach to obtain a spherical parameterization of a certain class of closed surfaces without holes. Our approach relies on empirical findings that can be mathematically investigated, to a certain extent, by using Laplace-Beltrami Operator and associated geometrical tools. The mapping proposed here is defined by considering only the three first non-trivial eigenfunctions of the Laplace-Beltrami Operator. Our approach requires a topological condition on those eigenfunctions, whose nodal domains must be 2. We show the efficiency of the approach through numerical experiments performed on cortical surface meshes

Surface smoothing: a way back in early brain morphogenesis.

International audienceIn this article we propose to investigate the analogy between early cortical folding process and cortical smoothing by mean curvature flow. First, we introduce a one-parameter model that is able to fit a developmental trajectory as represented in a Volume-Area plot and we propose an efficient optimization strategy for parameter estimation. Second, we validate the model on forty cortical surfaces of preterm newborns by comparing global geometrical indices and trajectories of central sulcus along developmental and simulation time

The frequency of severe Fetal Alcohol Spectrum Disorders in the neonatal period using data from the French hospital discharge database between 2006 and 2013.

At birth, only complete Fetal Alcohol Syndrome (FAS) can be properly diagnosed. However, other Consequences of prenatal Alcohol Exposure (CAE) can also be recorded. Our objective was to describe the frequency of diagnoses highly suggestive of "potential Fetal Alcohol Syndrome Disorder" (pFASD, i.e., FAS and CAE) among hospitalized neonates, during the neonatal period, in France, between 2006 and 2013. We used the French national hospital discharge database to identify the Q86.0 (FAS) and P04.3 (CAE) ICD-10 codes in hospital stays occurring in the first 28 days of life. FAS, CAE and pFASD rates were estimated per 1000 live births at the national level for the 2009-2013 period. We compared the 2006-2009 and 2010-2013 rates. The pFASD rates were also estimated at the regional level. Overall, 3,207 cases of pFASD were diagnosed during the neonatal period (i.e., 0.48 cases per 1000 live births, including 0.07 cases of FAS per 1000). Between 2006-2009 and 2010-2013, pFASD remained stable, despite a moderate decrease in reported FAS (0.08 vs 0.06 cases per 1000, p < 0.001). At the regional level, pFASD rates varied between 0.13 and 1.22 cases per 1000. This study provides the first national estimate of neonatal diagnosis of FAS, and more broadly pFASD, in France. Although our data certainly underestimate the real prevalence of FASD, they provide a minimal estimate of the burden of alcohol use during pregnancy. Observed variations deserve to be analyzed in the light of concomitant prevention and public information campaigns

Monitoring Fetal Alcohol Spectrum Disorder during the neonatal period in France

Abstract Background Alcohol is a known teratogenic and foetotoxic agent. At birth, only the complete foetal alcohol syndrome (FAS) and at most a suspicion for some incomplete syndromic forms can be diagnosed. Yet, other Consequences of prenatal Alcohol Exposure (CAE) can also be observed and recorded in the neonatal period. Our goal was to describe the frequency of diagnosis codes for FAS and CAE at the national and regional level. Methods Between 2006 and 2013, we identified the ICM-10 codes Q860 (FAS) and P043 (CAE) in the hospital records for stays occurring in the 28 first days of life in the French national health insurance database (SNDS). Our “potential Foetal Alcohol Spectrum Disorders group” (pFASD), included the FAS and CAE subgroups. The pFASD prevalence was estimated per 1000 live births at the national and regional levels overall and then comparing: 2006-2009 and 2010-2013. Results From 2006 to 2013, 3207 neonates were diagnosed with pFASD during the neonatal period, i.e. 0.48 cases per 1,000 live births, including 0.07‰ of FAS. Between 2006-2009 and 2010-2013, pFASD remained stable (p = 0.6). At the regional level, the proportion of pFASD was the most frequent in one of the overseas territories (La Reunion Island, 1.22‰ births) and in the north-eastern part of mainland France (0.90 ‰ births to 1.02 ‰). Conclusions This study is the first to produce a national estimate of the frequency of neonatal diagnosis of FAS. It shows a stability of the frequency of pFASD cases recorded over the 2006-2013 period which is certainly underestimated but gives a first minimal estimate of the burden of alcohol use during pregnancy in France. Key messages Alcohol use during pregnancy remains a public health issue in France. Estimating the prevalence of FAS is of undeniable priority given the public health implications of these disorders that hinder the development of children exposed, and their avoidable nature. </jats:sec