Scheduling Human Intelligence Tasks in Multi-Tenant Crowd-Powered Systems

Micro-task crowdsourcing has become a popular approach to effectively tackle complex data management problems such as data linkage, missing values, or schema matching. However, the backend crowdsourced operators of crowd-powered systems typically yield higher latencies than the machine-processable operators, this is mainly due to inherent efficiency differences between humans and machines. This problem can be further exacerbated by the lack of workers on the target crowdsourcing platform, or when the workers are shared unequally among a number of competing requesters; including the concurrent users from the same organization who execute crowdsourced queries with different types, priorities and prices. Under such conditions, a crowd-powered system acts mostly as a proxy to the crowdsourcing platform, and hence it is very difficult to provide effiency guarantees to its end-users. Scheduling is the traditional way of tackling such problems in computer science, by prioritizing access to shared resources. In this paper, we propose a new crowdsourcing system architecture that leverages scheduling algorithms to optimize task execution in a shared resources environment, in this case a crowdsourcing platform. Our study aims at assessing the efficiency of the crowd in settings where multiple types of tasks are run concurrently. We present extensive experimental results comparing i) different multi-tenant crowdsourcing jobs, including a workload derived from real traces, and ii) different scheduling techniques tested with real crowd workers. Our experimental results show that task scheduling can be leveraged to achieve fairness and reduce query latency in multi-tenant crowd-powered systems, although with very different tradeoffs compared to traditional settings not including human factors

Transcriptional Profiling of Human Liver Identifies Sex-Biased Genes Associated with Polygenic Dyslipidemia and Coronary Artery Disease

Sex-differences in human liver gene expression were characterized on a genome-wide scale using a large liver sample collection, allowing for detection of small expression differences with high statistical power. 1,249 sex-biased genes were identified, 70% showing higher expression in females. Chromosomal bias was apparent, with female-biased genes enriched on chrX and male-biased genes enriched on chrY and chr19, where 11 male-biased zinc-finger KRAB-repressor domain genes are distributed in six clusters. Top biological functions and diseases significantly enriched in sex-biased genes include transcription, chromatin organization and modification, sexual reproduction, lipid metabolism and cardiovascular disease. Notably, sex-biased genes are enriched at loci associated with polygenic dyslipidemia and coronary artery disease in genome-wide association studies. Moreover, of the 8 sex-biased genes at these loci, 4 have been directly linked to monogenic disorders of lipid metabolism and show an expression profile in females (elevated expression of ABCA1, APOA5 and LDLR; reduced expression of LIPC) that is consistent with the lower female risk of coronary artery disease. Female-biased expression was also observed for CYP7A1, which is activated by drugs used to treat hypercholesterolemia. Several sex-biased drug-metabolizing enzyme genes were identified, including members of the CYP, UGT, GPX and ALDH families. Half of 879 mouse orthologs, including many genes of lipid metabolism and homeostasis, show growth hormone-regulated sex-biased expression in mouse liver, suggesting growth hormone might play a similar regulatory role in human liver. Finally, the evolutionary rate of protein coding regions for human-mouse orthologs, revealed by dN/dS ratio, is significantly higher for genes showing the same sex-bias in both species than for non-sex-biased genes. These findings establish that human hepatic sex differences are widespread and affect diverse cell metabolic processes, and may help explain sex differences in lipid profiles associated with sex differential risk of coronary artery disease

Sexually dimorphic gene expression emerges with embryonic genome activation and is dynamic throughout development

This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public DomainVKR is supported by grants from the Biotechnology and Biological Sciences Research Council, UK (BB/M012494/1), VKR and CG by (BB/G00711/X/1). MLH is supported by a Research Council UK Academic Fellowship. RL is supported by EU-FP7 BLUEPRINT

Age and Diet Affect Gene Expression Profiles in Canine Liver Tissue

BACKGROUND: The liver plays a central role in nutrient and xenobiotic metabolism, but its functionality declines with age. Senior dogs suffer from many of the chronic hepatic diseases as elderly humans, with age-related alterations in liver function influenced by diet. However, a large-scale molecular analysis of the liver tissue as affected by age and diet has not been reported in dogs. METHODOLOGY/PRINCIPAL FINDINGS: Liver tissue samples were collected from six senior (12-year old) and six young adult (1-year old) female beagles fed an animal protein-based diet (APB) or a plant protein-based diet (PPB) for 12 months. Total RNA in the liver tissue was extracted and hybridized to Affymetrix GeneChip® Canine Genome Arrays. Using a 2.0-fold cutoff and false discovery rate <0.10, our results indicated that expression of 234 genes was altered by age, while 137 genes were differentially expressed by diet. Based on functional classification, genes affected by age and/or diet were involved in cellular development, nutrient metabolism, and signal transduction. In general, gene expression suggested that senior dogs had an increased risk of the progression of liver disease and dysfunction, as observed in aged humans and rodents. In particular for aged liver, genes related to inflammation, oxidative stress, and glycolysis were up-regulated, whereas genes related to regeneration, xenobiotic metabolism, and cholesterol trafficking were down-regulated. Diet-associated changes in gene expression were more common in young adult dogs (33 genes) as compared to senior dogs (3 genes). CONCLUSION: Our results provide molecular insight pertaining to the aged canine liver and its predisposition to disease and abnormalities. Therefore, our data may aid in future research pertaining to age-associated alterations in hepatic function or identification of potential targets for nutritional management as a means to decrease incidence of age-dependent liver dysfunction

Sexually dimorphic characteristics of the small intestine and colon of prepubescent C57BL/6 mice

Background There is increasing appreciation for sexually dimorphic effects, but the molecular mechanisms underlying these effects are only partially understood. In the present study, we explored transcriptomics and epigenetic differences in the small intestine and colon of prepubescent male and female mice. In addition, the microbiota composition of the colonic luminal content has been examined. Methods At postnatal day 14, male and female C57BL/6 mice were sacrificed and the small intestine, colon and content of luminal colon were isolated. Gene expression of both segments of the intestine was analysed by microarray analysis. DNA methylation of the promoter regions of selected sexually dimorphic genes was examined by pyrosequencing. Composition of the microbiota was explored by deep sequencing. Results Sexually dimorphic genes were observed in both segments of the intestine of 2-week-old mouse pups, with a stronger effect in the small intestine. Amongst the total of 349 genes displaying a sexually dimorphic effect in the small intestine and/or colon, several candidates exhibited a previously established function in the intestine (i.e. Nts, Nucb2, Alox5ap and Retnlγ). In addition, differential expression of genes linked to intestinal bowel disease (i.e. Ccr3, Ccl11 and Tnfr) and colorectal cancer development (i.e. Wt1 and Mmp25) was observed between males and females. Amongst the genes displaying significant sexually dimorphic expression, nine genes were histone-modifying enzymes, suggesting that epigenetic mechanisms might be a potential underlying regulatory mechanism. However, our results reveal no significant changes in DNA methylation of analysed CpGs within the selected differentially expressed genes. With respect to the bacterial community composition in the colon, a dominant effect of litter origin was found but no significant sex effect was detected. However, a sex effect on the dominance of specific taxa was observed. Conclusions This study reveals molecular dissimilarities between males and females in the small intestine and colon of prepubescent mice, which might underlie differences in physiological functioning and in disease predisposition in the two sexes

The perioperative cardioprotective effect of bisoprolol in vascular surgery patients is determined by the bisoprolol tissue levels

Cardiolog