An Effective Image Retrieval Mechanism Using Family-based Spatial Consistency Filtration with Object Region

How to construct an appropriate spatial consistent measurement is the key to improving image retrieval performance. To address this problem, this paper introduces a novel image retrieval mechanism based on the family filtration in object region. First, we supply an object region by selecting a rectangle in a query image such that system returns a ranked list of images that contain the same object, retrieved from the corpus based on 100 images, as a result of the first rank. To further improve retrieval performance, we add an efficient spatial consistency stage, which is named family-based spatial consistency filtration, to re-rank the results returned by the first rank. We elaborate the performance of the retrieval system by some experiments on the dataset selected from the key frames of ＂TREC Video Retrieval Evaluation 2005 （TRECVID2005）＂. The results of experiments show that the retrieval mechanism proposed by us has vast major effect on the retrieval quality. The paper also verifies the stability of the retrieval mechanism by increasing the number of images from 100 to 2000 and realizes generalized retrieval with the object outside the dataset.

Implicit Hypotheses Are Hidden Power Droppers in Family-Based Association Studies of Secondary Outcomes

Family-based tests of association between a genetic marker and a disease constitute a common design to dissect the genetic architecture of complex traits. The FBAT software is one of the most popular tools to perform such studies. However, researchers are also often interested in the genetic contribution to a more specific manifestation of the phenotype (e.g. severe vs. non-severe form) known as a secondary outcome. Here, what we demonstrate is the limited power of the classical formulation of the FBAT statistic to detect the effect of genetic variants that influence a secondary outcome, in particular when these variants also impact on the onset of the disease, the primary outcome. We prove that this loss of power is driven by an implicit hypothesis, and we propose a derivation of the original FBAT statistic, free from this implicit hypothesis. Finally, we demonstrate analytically that our new statistic is robust and more powerful than FBAT for the detection of association between a genetic variant and a secondary outcome.

An ensemble-based likelihood ratio approach for family-based genomic risk prediction

Objective: As one of the most popular designs used in genetic research, family-based design has been well recognized for its advantages, such as robustness against population stratification and admixture. With vast amounts of genetic data collected from family-based studies, there is a great interest in studying the role of genetic markers from the aspect of risk prediction. This study aims to develop a new statistical approach for family-based risk prediction analysis with an improved prediction accuracy compared with existing methods based on family history. Methods: In this study, we propose an ensemble-based likelihood ratio(ELR) approach, Fam-ELR, for family-based genomic risk prediction. Fam-ELR incorporates a clustered receiver operating characteristic(ROC) curve method to consider correlations among family samples, and uses a computationally efficient tree-assembling procedure for variable selection and model building. Results: Through simulations, Fam-ELR shows its robustness in various underlying disease models and pedigree structures, and attains better performance than two existing family-based risk prediction methods. In a real-data application to a family-based genome-wide dataset of conduct disorder, Fam-ELR demonstrates its ability to integrate potential risk predictors and interactions into the model for improved accuracy, especially on a genome-wide level. Conclusions: By comparing existing approaches, such as genetic risk-score approach, Fam-ELR has the capacity of incorporating genetic variants with small or moderate marginal effects and their interactions into an improved risk prediction model. Therefore, it is a robust and useful approach for high-dimensional family-based risk prediction, especially on complex disease with unknown or less known disease etiology.

Genetic mapping of quantitative trait loci in crops

Dissecting the genetic architecture of complex traits is an ongoing challenge for geneticists.Two complementary approaches for genetic mapping,linkage mapping and association mapping have led to successful dissection of complex traits in many crop species.Both of these methods detect quantitative trait loci(QTL) by identifying marker–trait associations,and the only fundamental difference between them is that between mapping populations,which directly determine mapping resolution and power.Based on this difference,we first summarize in this review the advances and limitations of family-based mapping and natural population-based mapping instead of linkage mapping and association mapping.We then describe statistical methods used for improving detection power and computational speed and outline emerging areas such as large-scale meta-analysis for genetic mapping in crops.In the era of next-generation sequencing,there has arisen an urgent need for proper population design,advanced statistical strategies,and precision phenotyping to fully exploit high-throughput genotyping.

Polymorphisms in programmed death-1 gene are not associated with chronic HBV infection in Chinese patients

AIM:To investigate the association between the programmed death-1(PD-1) polymorphisms and genetic susceptibility of chronic hepatitis B virus(HBV) infection in Chinese patients.METHODS:Two single nucleotide polymorphisms(SNPs),PD-1.1 G > A and PD-1.2 G > A,were genotyped in 539 patients with chronic HBV infection and 353 other family members(HbsAg-) from 256 nuclear families using polymerase chain reactiorestriction fragment length polymorphisms assay.The associations between PD-1 polymorphisms and genetic susceptibilityof chronic HBV infection were analyzed usng the familybased association analysis method.RESULTS:No association or linkage was detected among 539 patients.Univariate(single-marker) familybased association tests demonstrated that PD-1 genotypes,alleles and transmitted haplotypes are not associated with chronic HBV infection(all with P value more than 0.05).Transmission/disequilibrium test and sibship disequilibrium test analysis showed no excess of the alleles from heterozygous parents to affected offspring(P = 0.688880,P = 1.000000 respectively).CONCLUSION:The data demonstrated that PD-1.1 and PD-1.2 polymorphisms are not associated with chronic HBV infection in Chinese patients.

A Pilot Experience in the training of healthcare professionals to face the childhood obesity epidemic through family therapeutic education

Background: Obesity is a high-cost social disease, the management of which, usually assigned to general practice, is less supported by evidence-based medicine. Most general practitioners feel unprepared to face the problem. Objectives: In 2000, at the Pediatric Department of Ferrara, we started a Family Group Therapeutic Education Program for the treatment of childhood obesity. More than 300 families have attended the program. Following our positive results, we created a professional training course on therapeutic education, addressed to healthcare personnel involved in the treatment of childhood obesity. The purpose of the present study is to discover if it is possible to promote the development of a shared therapeutic education strategy for obesity, involving primary care physiccians/pediatricians, specialists and dietitians. Methods: The integrated professional training course consists of a four-day seminar along with an on-line course for distance learning. The assessment of the project takes into account the following criteria: a multidimensional questionnaire (a pre- and post-test which explores: knowledge, motivation, self-efficacy, methodology, communication, modeling, etc.), an appreciation questionnaire with responses collected over the course of 2 years. Moreover, the nine participants of our 2008 training course began to use the new therapeutic tools in their practice and six of them sent us the anthropometric measurements of patients whom they have treated over the past two years using this approach allows us to present outcomes in terms of implementation of this therapeutic education program in everyday professional practice. Results and Conclusions: The course was attended by 15 healthcare professionals: ten in 2008 and five in 2009, from different Italian centers. Results seem to indicate a great interest and appreciation by the participants. Results based on BMI z-score reduction of the children cared for by our trainees seem to support the efficacy of our educational method in clinical practice. If these preliminary results are confirmed, new training projects for the management of childhood obesity can be planned and addressed to a wider healthcare professional public.