1,388 research outputs found
UOLO - automatic object detection and segmentation in biomedical images
We propose UOLO, a novel framework for the simultaneous detection and
segmentation of structures of interest in medical images. UOLO consists of an
object segmentation module which intermediate abstract representations are
processed and used as input for object detection. The resulting system is
optimized simultaneously for detecting a class of objects and segmenting an
optionally different class of structures. UOLO is trained on a set of bounding
boxes enclosing the objects to detect, as well as pixel-wise segmentation
information, when available. A new loss function is devised, taking into
account whether a reference segmentation is accessible for each training image,
in order to suitably backpropagate the error. We validate UOLO on the task of
simultaneous optic disc (OD) detection, fovea detection, and OD segmentation
from retinal images, achieving state-of-the-art performance on public datasets.Comment: Publised on DLMIA 2018. Licensed under the Creative Commons
CC-BY-NC-ND 4.0 license: http://creativecommons.org/licenses/by-nc-nd/4.0
Retinal blood vessels extraction using probabilistic modelling
Š 2014 Kaba et al.; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.This article has been made available through the Brunel Open Access Publishing Fund.The analysis of retinal blood vessels plays an important role in detecting and treating retinal diseases. In this review, we present an automated method to segment blood vessels of fundus retinal image. The proposed method could be used to support a non-intrusive diagnosis in modern ophthalmology for early detection of retinal diseases, treatment evaluation or clinical study. This study combines the bias correction and an adaptive histogram equalisation to enhance the appearance of the blood vessels. Then the blood vessels are extracted using probabilistic modelling that is optimised by the expectation maximisation algorithm. The method is evaluated on fundus retinal images of STARE and DRIVE datasets. The experimental results are compared with some recently published methods of retinal blood vessels segmentation. The experimental results show that our method achieved the best overall performance and it is comparable to the performance of human experts.The Department of Information Systems, Computing and Mathematics, Brunel University
Quercetin elevates p27Kip1 and arrests both primary and HPV16 E6/E7 transformed human keratinocytes in G1
Our previous work with primary bovine fibroblasts demonstrated that quercetin, a potent mutagen found in high levels in bracken fern (Pteridium aquilinum), arrested cells in G1 and G2/M, in correlation with p53 activation. The expression of bovine papillomavirus type 4 (BPV-4) E7 overcame this arrest and lead to the development of tumorigenic cells lines (Beniston et al., 2001). Given the possible link between papillomavirus infection, bracken fern in the diet and cancer of the upper gastrointestinal (GI) tract in humans, we investigated whether a similar situation would occur in human cells transformed by human papillomavirus type 16 (HPV-16) oncoproteins. Quercetin arrested primary human foreskin keratinocytes in G1. Arrest was linked to an elevation of the cyclin-dependent kinase inhibitor (cdki) p27Kip1. Expression of the HPV16 E6 and E7 oncoproteins in transformed cells failed to abrogate cell cycle arrest. G1 arrest in the transformed cells was also linked to an increase of p27Kip1 with a concomitant reduction of cyclin E-associated kinase activity. This elevation of p27Kip1 was due not only to increased protein half-life, but also to increased mRNA transcription
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A prospective seroepidemiological study of toxocariasis during early childhood in coastal Ecuador: potential for congenital transmission and risk factors for infection.
BACKGROUND: Although Toxocara spp. infection has a worldwide distribution, to our knowledge, no data from birth cohorts have been reported in published studies on the potential for congenital transmission and determinants of infection in early childhood. METHODS: We followed 290 mother-infant pairs from birth to 5 years of age through periodic collection of data and samples at birth, 7 and 13 months and 2, 3 and 5 years of age. Data on potential risk factors and confounders were collected by maternal questionnaire. Blood for plasma was collected from the mother at time of birth and periodically from the child for detection of anti-Toxocara spp. immunoglobulin G (IgG) antibodies using a Toxocara canis larval excretory-secretory antigen-based enzyme-linked immunosorbent assay. Stool samples were collected from the mother around the time of birth and periodically from the child for microscopic detection of soil-transmitted helminths (STH). Associations between potential risk factors and Toxocara spp. seroprevalence and seroconversion were estimated using multivariable logistic regression and generalized estimating equations. RESULTS: Toxocara spp. seroprevalence was 80.7% in mothers and in children was 0%, 9.3%, 48.4%, 64.9%, and 80.9% at 7 months, 13 months, 2, 3 and 5 years, respectively. Risk factors significantly associated with increases in seroprevalence over the first 5 years of life in multivariable analyses were age [Odds ratio (OR) 2.06, 95% confidence interval (CI) 1.39-2.27, Pâ<Â 0001], male sex (female vs. male: OR 0.66, 95% CI 0.48-0.89, Pâ=â0.006), maternal ethnicity (non-Afro vs. Afro-Ecuadorian: OR 0.65, 95% CI 0.47-0.91, Pâ=â0.011), lower maternal educational and socioeconomic level, and childhood STH (OR 2.29, 95% CI 1.51-3.47, Pâ<â0.001). Seroconversion rates for infection were greatest at 2 years of age (3.8%/month). Factors associated significantly with seroconversion at 2, 3 or 5 years were childhood STH infection, male sex, and more frequent domestic cat exposure. CONCLUSIONS: Our data, from an area of high Toxocara spp. endemicity, indicate no congenital transmission but high rates of seroconversion after 13 months of age reaching maternal levels of seroprevalence by 5 years of age. Factors associated with seroprevalence and seroconversion included STH infections, domestic cats, maternal ethnicity, male sex, STH infections, and markers of greater poverty
Integrating isotopes and documentary evidence : dietary patterns in a late medieval and early modern mining community, Sweden
We would like to thank the Archaeological Research Laboratory, Stockholm University, Sweden and the Tandem Laboratory (Ă
ngstrĂśm Laboratory), Uppsala University, Sweden, for undertaking the analyses of stable nitrogen and carbon isotopes in both human and animal collagen samples. Also, thanks to Elin Ahlin Sundman for providing the δ13C and δ15N values for animal references from VästerĂĽs. This research (BäckstrĂśmâs PhD employment at Lund University, Sweden) was supported by the Berit Wallenberg Foundation (BWS 2010.0176) and Jakob and Johan SĂśderbergâs foundation. The âSala projectâ (excavations and analyses) has been funded by Riksens Clenodium, Jernkontoret, Birgit and Gad Rausingâs Foundation, SAUâs Research Foundation, the Royal Physiographic Society of Lund, Berit Wallenbergs Foundation, Ă
ke Wibergs Foundation, Lars Hiertas Memory, Helge Ax:son Johnsonâs Foundation and The Royal Swedish Academy of Sciences.Peer reviewedPublisher PD
Genetic characterization of morphologically variant strains of Paracoccidioides brasiliensis
Molecular characterization of Paracoccidioides brasiliensis variant strains that had been preserved under mineral oil for decades was carried out by random amplified polymorphic DNA analysis (RAPD). On P. brasiliensis variants in the transitional phase and strains with typical morphology, RAPD produced reproducible polymorphic amplification products that differentiated them. A dendrogram based on the generated RAPD patterns placed the 14 P. brasiliensis strains into five groups with similarity coefficients of 72%. A high correlation between the genotypic and phenotypic characteristics of the strains was observed. A 750 bp-RAPD fragment found only in the wild-type phenotype strains was cloned and sequenced. Genetic similarity analysis using BLASTx suggested that this RAPD marker represents a putative domain of a hypothetical flavin-binding monooxygenase (FMO)-like protein of Neurospora crassa.FiocruzBritish Council Progra
EvaluaciĂłn clĂnica preliminar del efecto antiparasitario de Stevia rebaudiana Bertoni (ka`a he ĂŞ) en adultos y niĂąos
La parasitosis gastrointestinal es una enfermedad que se da preferentemente en la niĂąez y enadultos inmunocomprometidos. Los tratamientos actuales son, en general, eficaces, pero lacreciente resistencia a los antiparasitarios obliga a la bĂşsqueda de nuevas drogas con urgencia.Este estudio tiene el propĂłsito de evaluar preliminarmente la efectividad de Stevia rebaudianaBertoni como antiparasitĂĄrio. Se realizĂł un ensayo clĂnico aleatorizado a ciego simple, con 22adultos y 134 niĂąos (6-18 aĂąos), todos parasitados con helmintos y/o protozoarios. Lostratamientos asignados al azar consistieron en comprimidos de S. rebaudiana (SRB) omebendazol-tinidazol (MBZ-TNZ), ambos en preparaciones farmacĂŠuticas comerciales. En losadultos SRB y MBZ-TNZ redujeron en forma similar la infecciĂłn por protozoarios y helmintos, y elnĂşmero de eventos adversos informados para el tratamiento convencional fue mayor que para SRB(p<0,02). Atendiendo a esos resultados se ampliĂł la evaluaciĂłn a 134 niĂąos portadores deparĂĄsitos intestinales, de los que 113 (99,3%) presentaron protozoarios y 28 (20,8%) helmintos,mayoritariamente en co infecciĂłn. S. rebaudiana redujo significativamente (p<0,001) la frecuenciade global de infecciĂłn por protozoarios (74,5%) en los niĂąos frente a lo obtenido con MBZ-TNZ(40,7%), destacando la negativizaciĂłn de Giardia lamblia.que resultĂł el doble con SRB de loobservado con MBZ-TNZ (p<0,001). SRB redujo la frecuencia de helmintos en 70,6% de manerasimilar a MBZ-TNZ (p>0,05). No se registraron efectos adversos asociados a los tratamientos a losniĂąos/as. Los resultados animan a proseguir la evaluaciĂłn de SRB como potencial agenteantiparasitario
Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV
The performance of muon reconstruction, identification, and triggering in CMS
has been studied using 40 inverse picobarns of data collected in pp collisions
at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection
criteria covering a wide range of physics analysis needs have been examined.
For all considered selections, the efficiency to reconstruct and identify a
muon with a transverse momentum pT larger than a few GeV is above 95% over the
whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4,
while the probability to misidentify a hadron as a muon is well below 1%. The
efficiency to trigger on single muons with pT above a few GeV is higher than
90% over the full eta range, and typically substantially better. The overall
momentum scale is measured to a precision of 0.2% with muons from Z decays. The
transverse momentum resolution varies from 1% to 6% depending on pseudorapidity
for muons with pT below 100 GeV and, using cosmic rays, it is shown to be
better than 10% in the central region up to pT = 1 TeV. Observed distributions
of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO
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