143 research outputs found
Photograph-based diagnosis of burns in patients with dark-skin types: The importance of case and assessor characteristics
AbstractAimThis study assessed whether photographs of burns on patients with dark-skin types could be used for accurate diagnosing and if the accuracy was affected by physicians’ clinical background or case characteristics.Method21 South-African cases (Fitzpatrick grades 4–6) of varying complexity were photographed using a camera phone and uploaded on a web-survey. Respondents were asked to assess wound depth (3 categories) and size (in percentage). A sample of 24 burn surgeons and emergency physicians was recruited in South-Africa, USA and Sweden. Measurements of accuracy (using percentage agreement with bedside diagnosis), inter- (n=24), and intra-rater (n=6) reliability (using percentage agreement and kappa) were computed for all cases aggregated and by case characteristic.ResultsOverall diagnostic accuracy was 67.5% and 66.0% for burn size and depth, respectively. It was comparable between burn surgeons and emergency physicians and between countries of practice. However, the standard deviations were smaller, showing higher similarities in diagnoses for burn surgeons and South-African clinicians compared to emergency physicians and clinicians from other countries. Case characteristics (child/adult, simple/complex wound, partial/full thickness) affected the results for burn size but not for depth. Inter- and intra-rater reliability for burn depth was 55% and 77%.ConclusionSize and depth of burns on patients with dark-skin types could be assessed at least as well using photographs as at bedside with 67.5% and 66.0% average accuracy rates. Case characteristics significantly affected the accuracy for burn size, but medical specialty and country of practice seldom did in a statistically significant manner
Development and evaluation of deep learning algorithms for assessment of acute burns and the need for surgery
Assessment of burn extent and depth are critical and require very specialized diagnosis. Automated image-based algorithms could assist in performing wound detection and classification. We aimed to develop two deep-learning algorithms that respectively identify burns, and classify whether they require surgery. An additional aim assessed the performances in different Fitzpatrick skin types. Annotated burn (n = 1105) and background (n = 536) images were collected. Using a commercially available platform for deep learning algorithms, two models were trained and validated on 70% of the images and tested on the remaining 30%. Accuracy was measured for each image using the percentage of wound area correctly identified and F1 scores for the wound identifier; and area under the receiver operating characteristic (AUC) curve, sensitivity, and specificity for the wound classifier. The wound identifier algorithm detected an average of 87.2% of the wound areas accurately in the test set. For the wound classifier algorithm, the AUC was 0.885. The wound identifier algorithm was more accurate in patients with darker skin types; the wound classifier was more accurate in patients with lighter skin types. To conclude, image-based algorithms can support the assessment of acute burns with relatively good accuracy although larger and different datasets are needed.Peer reviewe
Investigating population dynamics from parentage analysis in the highly endangered fan mussel Pinna nobilis
Understanding dispersal patterns is a major focus for conservation biology as it influences
local survival and resilience in case of local disturbance, particularly for sessile
species. Dispersal can be assessed through parentage analyses by estimating family
structure and self-recruitment.
This study documents the family structure of a pelagic
spawner, Pinna nobilis, which is facing a major crisis that threatens its survival as most
of its populations have been decimated by a parasite, Haplosporidium pinnae. In this
context, we focused on a single population (Peyrefite, Banyuls-sur-
mer,
France) where
640 individuals were sampled in 2011, 2015, and 2018 and genotyped for 22 microsatellite
markers. Genetic diversity was high and homogeneous among years, with
mean allele numbers ranging between 13.6 and 14.8 and observed heterozygosities
(Ho) between 0.7121 and 0.7331. Low, but significant, genetic differentiations were
found between 2011–2015
and 2015–2018.
A parentage analysis described 11 clusters,
including one prevailing, and revealed that 46.9% of individuals were involved in
half-sib
relationships, even between years, suggesting that source populations were
recurrent year after year. There were few individuals resampled between years (30
in 2015 and 14 in 2018), indicating a rapid turnover. Considering the large number
of half-sib
relationships but the low number of relations per individual, we conclude
that P. nobilis exhibit homogeneous reproductive success. Self-recruitment
was not
detected, making this population highly vulnerable as replenishment only relies on
connectivity from neighboring populations. In the context of the pandemic caused by
H. pinnae, these results will have to be considered when choosing a location to reintroduce
individuals in potential future rescue plans.En prensa
Formation et esprit d'entreprendre chez les étudiants
Cette contribution s'attache à étudier entre esprit d'entreprendre et domaine d'études chez les étudiants français. L'esprit d'entreprendre est le substrat dans lequel peut germer l'intention qui pourra donner lieu à une création d'entreprise. Nous choisissons de l'appréhender à partir d'une grille de lecture dérivée du modèle psychosocial du comportement planifié d'Ajzen, enrichie par des variables reflétant l'implication dans la vie associative et les opinions sur les formations à la création d'entreprise.esprit d'entreprendre ; domaine d'étude ; étudiants français
Genetic homogeneity of the critically endangered fan mussel, Pinna nobilis, throughout lagoons of the Gulf of Lion (North‑Western Mediterranean Sea)
The fan mussel, Pinna nobilis, endemic to the Mediterranean Sea, is a critically endangered species
facing mass mortality events in almost all of its populations, following the introduction of the parasite
Haplosporidium pinnae. Such a unique pandemic in a marine organism, which spreads rapidly and
with mortality rates reaching up to 100%, could lead to the potential extinction of the species. Only
few regions, involving lagoon habitats, remain healthy throughout the entire Mediterranean Sea.
This study describes the genetic structure of P. nobilis across the Gulf of Lion, including confined
locations such as lagoons and ports. A total of 960 samples were collected among 16 sites distributed
at 8 localities, and then genotyped using 22 microsatellite markers. Genetic diversity was high in all
sites with mean allele numbers ranging between 10 and 14.6 and with observed heterozygosities (Ho)
between 0.679 and 0.704. No genetic differentiation could be identified (FST ranging from 0.0018 to
0.0159) and the percentages of related individuals were low and similar among locations (from 1.6 to
6.5%). Consequently, all fan mussels, over the entire coastline surveyed, including those in the most
geographically isolated areas, belong to a large genetically homogeneous population across the Gulf
of Lion. Considering the ongoing mass mortality context, this result demonstrates that almost all of
the genetic diversity of P. nobilis populations is still preserved even in isolated lagoons, which might
represent a refuge habitat for the future of the species.En prensa2,92
Thyroid cancer following nuclear tests in French Polynesia
BACKGROUND: Between 1966 and 1974, France conducted 41 atmospheric nuclear tests in Polynesia, but their potential health effects have not previously been investigated. METHODS: In a case-control study, we compared the radiation exposure of almost all the French Polynesians diagnosed with differentiated thyroid carcinoma between 1981 and 2003 (n = 229) to the exposure of 373 French Polynesian control individuals without cancer from the general population. Radiation exposures were estimated using measurements after the nuclear tests, age at time of each test, residential and dietary information. RESULTS: The average thyroid dose before 15 years of age was about 1.8 mGy, and 5% of the cases and 3% of the controls received a dose above 10 mGy. Despite this low level of dose, and after adjusting for ethnic group, level of education, body surface area, family history of thyroid cancer and number of pregnancies for women, we observed an increasing risk (P = 0.04) of thyroid cancer with increasing thyroid dose received before age of 15 years, which remained after excluding non-aggressive differentiated thyroid micro-carcinomas. This increase of risk per unit of thyroid radiation dose was higher (P = 0.03) in women who later experienced four or more pregnancies than among other women. CONCLUSION: The risk estimate is low, but is based on limited exposure data. The release of information on exposure, currently classified, would greatly improve the reliability of the risk estimation. British Journal of Cancer (2010) 103, 1115-1121. doi: 10.1038/sj.bjc.6605862 www.bjcancer.com Published online 31 August 2010 (c) 2010 Cancer Research U
An efficient method to find potentially universal population genetic markers, applied to metazoans
<p>Abstract</p> <p>Background</p> <p>Despite the impressive growth of sequence databases, the limited availability of nuclear markers that are sufficiently polymorphic for population genetics and phylogeography and applicable across various phyla restricts many potential studies, particularly in non-model organisms. Numerous introns have invariant positions among kingdoms, providing a potential source for such markers. Unfortunately, most of the few known EPIC (Exon Primed Intron Crossing) loci are restricted to vertebrates or belong to multigenic families.</p> <p>Results</p> <p>In order to develop markers with broad applicability, we designed a bioinformatic approach aimed at avoiding multigenic families while identifying intron positions conserved across metazoan phyla. We developed a program facilitating the identification of EPIC loci which allowed slight variation in intron position. From the <it>Homolens </it>databases we selected 29 gene families which contained 52 promising introns for which we designed 93 primer pairs. PCR tests were performed on several ascidians, echinoderms, bivalves and cnidarians. On average, 24 different introns per genus were amplified in bilaterians. Remarkably, five of the introns successfully amplified in all of the metazoan genera tested (a dozen genera, including cnidarians). The influence of several factors on amplification success was investigated. Success rate was not related to the phylogenetic relatedness of a taxon to the groups that most influenced primer design, showing that these EPIC markers are extremely conserved in animals.</p> <p>Conclusions</p> <p>Our new method now makes it possible to (i) rapidly isolate a set of EPIC markers for any phylum, even outside the animal kingdom, and thus, (ii) compare genetic diversity at potentially homologous polymorphic loci between divergent taxa.</p
Environmental variables, habitat discontinuity and life history shaping the genetic structure of Pomatoschistus marmoratus
Coastal lagoons are semi-isolated ecosystems
exposed to wide fluctuations of environmental conditions
and showing habitat fragmentation. These features may
play an important role in separating species into different
populations, even at small spatial scales. In this study, we
evaluate the concordance between mitochondrial (previous
published data) and nuclear data analyzing the genetic
variability of Pomatoschistus marmoratus in five localities,
inside and outside the Mar Menor coastal lagoon (SE
Spain) using eight microsatellites. High genetic diversity
and similar levels of allele richness were observed across
all loci and localities, although significant genic and
genotypic differentiation was found between populations
inside and outside the lagoon. In contrast to the FST values
obtained from previous mitochondrial DNA analyses
(control region), the microsatellite data exhibited significant
differentiation among samples inside the Mar Menor
and between lagoonal and marine samples. This pattern
was corroborated using Cavalli-Sforza genetic distances.
The habitat fragmentation inside the coastal lagoon and
among lagoon and marine localities could be acting as a
barrier to gene flow and contributing to the observed
genetic structure. Our results from generalized additive
models point a significant link between extreme lagoonal
environmental conditions (mainly maximum salinity) and
P. marmoratus genetic composition. Thereby, these environmental
features could be also acting on genetic structure
of coastal lagoon populations of P. marmoratus favoring
their genetic divergence. The mating strategy of P. marmoratus
could be also influencing our results obtained from
mitochondrial and nuclear DNA. Therefore, a special
consideration must be done in the selection of the DNA
markers depending on the reproductive strategy of the
species
Global Diversity of Brittle Stars (Echinodermata: Ophiuroidea)
This review presents a comprehensive overview of the current status regarding the global diversity of the echinoderm class Ophiuroidea, focussing on taxonomy and distribution patterns, with brief introduction to their anatomy, biology, phylogeny, and palaeontological history. A glossary of terms is provided. Species names and taxonomic decisions have been extracted from the literature and compiled in The World Ophiuroidea Database, part of the World Register of Marine Species (WoRMS). Ophiuroidea, with 2064 known species, are the largest class of Echinodermata. A table presents 16 families with numbers of genera and species. The largest are Amphiuridae (467), Ophiuridae (344 species) and Ophiacanthidae (319 species). A biogeographic analysis for all world oceans and all accepted species was performed, based on published distribution records. Approximately similar numbers of species were recorded from the shelf (n = 1313) and bathyal depth strata (1297). The Indo-Pacific region had the highest species richness overall (825 species) and at all depths. Adjacent regions were also relatively species rich, including the North Pacific (398), South Pacific (355) and Indian (316) due to the presence of many Indo-Pacific species that partially extended into these regions. A secondary region of enhanced species richness was found in the West Atlantic (335). Regions of relatively low species richness include the Arctic (73 species), East Atlantic (118), South America (124) and Antarctic (126)
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