139 research outputs found
Atherosclerotic carotid plaque composition: a 3T and 7T MRI-histology correlation study
Background and Purpose
Carotid artery atherosclerotic plaque composition may influence plaque stability and risk of
thromboembolic events, and non-invasive plaque imaging may therefore permit risk
stratification for clinical management. Plaque composition was compared using non-invasive
in-vivo (3T) and ex-vivo (7T) MRI and histopathological examination.
Methods
Thirty three endarterectomy cross sections, from 13 patients, were studied. The datasets
consisted of in-vivo 3T MRI, ex-vivo 7T MRI and histopathology. Semi-automated
segmentation methods were used to measure areas of different plaque components. Bland-
Altman plots and mean difference with 95% confidence interval were carried out.
Results
There was general quantitative agreement between areas derived from semi-automated
segmentation of MRI data and histology measurements. The mean differences and 95%
confidence bounds in the relative to total plaque area between 3T versus Histology were:
fibrous tissue 4.99 % (-4.56 to 14.56), lipid-rich/necrotic core (LR/NC) with haemorrhage -
1.81% (-14.11 to 10.48), LR/NC without haemorrhage -2.43% (-13.04 to 8.17), and
calcification -3.18% (-11.55 to 5.18). The mean differences and 95% confidence bounds in
the relative to total plaque area between 7T and histology were: fibrous tissue 3.17 % (-3.17
to 9.52), LR/NC with haemorrhage -0.55% (-9.06 to 7.95), LR/NC without haemorrhage -
12.62% (-19.8 to -5.45), and calcification -2.43% (-9.97 to 4.73).
Conclusions
This study provides evidence that semi-automated segmentation of 3T/7T MRI techniques
can help to determine atherosclerotic plaque composition. In particular, the high resolution of
ex-vivo 7T data was able to highlight greater detail in the atherosclerotic plaque composition.
High field MRI may therefore have advantages for in vivo carotid plaque MR imaging
Review of the initial validation and characterization of a chicken 3K SNP array.
In 2004 the chicken genome sequence and more than 2.8 million single nucleotide polymorphisms (SNPs) were reported. This information greatly enhanced the ability of poultry scientists to understand chicken biology, especially with respect to identification of quantitative trait loci (QTL) and genes that control simple and complex traits. To validate and address the quality of the reported SNPs, assays for 3072 SNPS were developed and used to genotype 2576 DNAs isolated from commercial and experimental birds. Over 90% of the SNPs were valid based on the criterion used for segregating, and over 88% had a minor allele frequency of 2% or greater. As the East Lansing (EL) and Wageningen University (WAU) reference panels were genotyped, 1933 SNPs were added to the chicken genetic map, which was used in the second chicken genome sequence assembly. It was also discovered that linkage disequilibrium varied considerably between commercial layers and broilers; with the latter having haplotype blocks averaging 10 to 50 kb in size. Finally, it was estimated that commercial lines have lost 70% or more of their genetic diversity, with the majority of allele loss attributable to the limited number of chicken breeds used
An overview of research activities and achievement in Geotechnics from the Scottish Universities Geotechnics Network (SUGN)
ABSTRACT: Design of geotechnical systems is often challenging as it requires the understanding of complex soil behaviour and its influence on field-scale performance of geo-structures. To advance the scientific knowledge and the technological development in geotechnical engineering, a Scottish academic community, named Scottish Universities Geotechnics Network (SUGN), was established in 2001, composing of eight higher education institutions. The network gathers geotechnics researchers, including experimentalists as well as centrifuge, constitutive, and numerical modellers, to generate multiple synergies for building larger collaboration and wider research dissemination in and beyond Scotland. The paper will highlight the research excellence and leading work undertaken in SUGN emphasising some of the contribution to the geotechnical research community and some of the significant research outcomes. RÉSUMÉ: Conception de systèmes géotechniques est souvent difficile car elle nécessite la compréhension du comportement des sols complexes et son influence sur la performance échelle du champ de géo-structures. Pour faire avancer la connaissance scientifique et le développement technologique en ingénierie géotechnique, une communauté universitaire écossais, nommé écossais universités Géotechnique réseau (SUGN), a été créé en 2001, la composition des huit établissements d'enseignement supérieur. Le réseau réunit géotechnique chercheurs, y compris les expérimentateurs ainsi que centrifugeuse, constitutif, et les modélisateurs numériques, de générer des synergies multiples pour la construction de plus grande collaboration et une plus large diffusion de la recherche en Ecosse et au-delà. Le document mettra l'accent sur l'excellence de la recherche et de diriger le travail entrepris dans SUGN soulignant certains de la contribution à la communauté de recherche en géotechnique et certains des résultats importants de la recherche
Use of a type IIB external skeletal fixator in experimental tarsocrural arthrodesis in dogs
The aim of the present study was to evaluate the usefulness of type IIb external skeletal fixators with a transarticular pin in experimental tarsocrural arthrodesis. Twelve adult mongrel dogs of both sexes, ranging in age from two to five years and weighing 12 to 25kg, were used. The configuration of the fixator consisted in the application of a transarticular Steinmann pin and of centrally threaded pins to the proximal portion of the tibia and calcaneus and to the distal portion of the metatarsal bones. In addition, Schanz pins were inserted into the medial and lateral side of the tibia and into the medial side of the metatarsal bones. Radiographs were taken 15; 30 and 45 days after surgery. Bone fusion of the treated joints were observed at 30 days in all animals, and the implants were removed after 45 days. Loosening of the centrally threaded pins was observed in all groups, especially for those applied to the calcaneus. The configuration of the external fixator proposed here was found to be satisfactory in terms of bone union for all joints during the same period, irrespective of the weight of the animal.União Metropolitana para o Desenvolvimento da Educação e Cultura Faculdade Agrária e de Saúde, Lauro, de Freitas, BahiaUniversidade Federal da Bahia Escola de Medicina Veterinária e Zootecnia Departamento de Patologia e Clínicas Veterinárias, Salvador, BahiaUniversidade Estadual Paulista Faculdade de Ciências Agrárias e Veterinárias Departamento de Clínica e Cirurgia Veterinária, Jaboticabal, São PauloCentro Universitário de Rio Preto, Rio Preto, São PauloUniversidade Federal de Goiás Escola de Veterinária, Goiania, GoiásUniversidade Estadual Paulista Faculdade de Ciências Agrárias e Veterinárias Departamento de Clínica e Cirurgia Veterinária, Jaboticabal, São Paul
Digestibilidade e ganhos em peso de ovinos alimentados com diferentes fontes de volumosos e recebendo somatotropina recombinante bovina (rBST)
O objetivo deste trabalho foi avaliar os efeitos da aplicação de 20 mg de somatotropina recombinante bovina (rBST) de liberação lenta, em períodos de 14 e 28 dias, sobre a ingestão de matéria seca, os coeficientes de digestibilidade de matéria seca (MS), fibra em detergente ácido (FDA), proteína bruta (PB) e energia bruta (EB), o balanço de nitrogênio e o ganho de peso diário, em rações à base de silagem de milho, cana-de-açúcar ou bagaço hidrolisado e concentrado. Foi usado um total de 24 borregos mestiços, não-castrados, com média de 4 a 5 meses de idade e 22 ± 2 kg de PV. Não houve efeito da rBST na ingestão de matéria seca, nas digestibilidades de PB e FDA, no balanço de nitrogênio e no ganho de peso diário dos borregos. A digestibilidade da energia bruta foi influenciada pela aplicação de rBST, quando os diferentes volumosos ou períodos pós-aplicação hormonal foram considerados, porém, somente foi observado efeito da ação hormonal sobre a digestibilidade de MS nas dietas à base de silagem de milho.The objective of this work was to evaluate the effect of the administration of 20 mg of slow liberation bovine somatotropin (rBST) on the dry matter intake and on the digestibility coefficient of dry matter (MS), acid detergent fiber, crude protein, crude energy, nitrogen balance and the daily weight gain in lambs fed diets based on corn silage, sugar cane or hydrolyzed bagasse and concentrate. Twenty-four crossbred lambs, averaging 4-5 months of age and 22 + 2 kg LW, were used. There was no effect of the rBST on the dry matter intake, the digestibilities of crude protein, acid detergent fiber, the nitrogen balance and the daily weight gain of the lambs. The gross energy digestibility was affected by the rBST administration when different forages or periods post hormonal administration were considered, however, the effect of the hormonal action was observed only on the dry matter digestibility of corn silage diets
Genetic parameters for egg and related characteristics of white Leghorn hens in a subtropical environment
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