Search results for "20(60)"
showing 10 items of 368 documents
Efficient Algorithms for Sequence Analysis with Entropic Profiles
2017
Entropy, being closely related to repetitiveness and compressibility, is a widely used information-related measure to assess the degree of predictability of a sequence. Entropic profiles are based on information theory principles, and can be used to study the under-/over-representation of subwords, by also providing information about the scale of conserved DNA regions. Here, we focus on the algorithmic aspects related to entropic profiles. In particular, we propose linear time algorithms for their computation that rely on suffix-based data structures, more specifically on the truncated suffix tree (TST) and on the enhanced suffix array (ESA). We performed an extensive experimental campaign …
Discriminating graph pattern mining from gene expression data
2016
We consider the problem of mining gene expression data in order to single out interesting features that characterize healthy/unhealthy samples of an input dataset. We present and approach based on a network model of the input gene expression data, where there is a labelled graph for each sample. To the best of our knowledge, this is the first attempt to build a different graph for each sample and, then, to have a database of graphs for representing a sample set. Out main goal is that of singling out interesting differences between healthy and unhealthy samples, through the extraction of "discriminating patterns" among graphs belonging to the two different sample sets. Differently from the …
Applying Conceptual Modeling to Better Understand the Human Genome
2016
The objective of the work is to present the benefits of the application of Conceptual Modeling (CM) in complex domains, such as genomics. This paper explains the evolution of a Conceptual Schema of the Human Genome (CSHG), which seeks to provide a clear and precise understanding of the human genome. We want to highlighting all the advantages of the application of CM in a complex domain such as Genomic Information Systems (GeIS). We show how over time this model has evolved, thus we have discovered better forms of representation. As we advanced in exploring the domain, we understood that we should be extending and incorporating the new concepts detected into our model. Here we present and di…
Parallel Pairwise Epistasis Detection on Heterogeneous Computing Architectures
2016
This is a post-peer-review, pre-copyedit version of an article published in IEEE Transactions on Parallel and Distributed Systems. The final authenticated version is available online at: http://dx.doi.org/10.1109/TPDS.2015.2460247. [Abstract] Development of new methods to detect pairwise epistasis, such as SNP-SNP interactions, in Genome-Wide Association Studies is an important task in bioinformatics as they can help to explain genetic influences on diseases. As these studies are time consuming operations, some tools exploit the characteristics of different hardware accelerators (such as GPUs and Xeon Phi coprocessors) to reduce the runtime. Nevertheless, all these approaches are not able t…
The colored longest common prefix array computed via sequential scans
2018
Due to the increased availability of large datasets of biological sequences, the tools for sequence comparison are now relying on efficient alignment-free approaches to a greater extent. Most of the alignment-free approaches require the computation of statistics of the sequences in the dataset. Such computations become impractical in internal memory when very large collections of long sequences are considered. In this paper, we present a new conceptual data structure, the colored longest common prefix array (cLCP), that allows to efficiently tackle several problems with an alignment-free approach. In fact, we show that such a data structure can be computed via sequential scans in semi-exter…
3d collagen hydrogel promotes in vitro langerhans islets vascularization through ad-mvfs angiogenic activity
2021
Adipose derived microvascular fragments (ad-MVFs) consist of effective vascularization units able to reassemble into efficient microvascular networks. Because of their content in stem cells and related angiogenic activity, ad-MVFs represent an interesting tool for applications in regenerative medicine. Here we show that gentle dissociation of rat adipose tissue provides a mixture of ad-MVFs with a length distribution ranging from 33–955 μm that are able to maintain their original morphology. The isolated units of ad-MVFs that resulted were able to activate transcriptional switching toward angiogenesis, forming tubes, branches, and entire capillary networks when cultured in 3D collagen type-…
Effect of Low-Intensity Pulsed Ultrasound on Osteogenic Human Mesenchymal Stem Cells Commitment in a New Bone Scaffold
2017
Purpose Bone tissue engineering is helpful in finding alternatives to overcome surgery limitations. Bone growth and repair are under the control of biochemical and mechanical signals; therefore, in recent years several approaches to improve bone regeneration have been evaluated. Osteo-inductive biomaterials, stem cells, specific growth factors and biophysical stimuli are among those. The aim of the present study was to evaluate if low-intensity pulsed ultrasound stimulation (LIPUS) treatment would improve the colonization of an MgHA/Coll hybrid composite scaffold by human mesenchymal stem cells (hMSCs) and their osteogenic differentiation. LIPUS stimulation was applied to hMSCs cultured on …
Search for a Minimal Set of Parameters by Assessing the Total Optimization Potential for a Dynamic Model of a Biochemical Network.
2017
Selecting an efficient small set of adjustable parameters to improve metabolic features of an organism is important for a reduction of implementation costs and risks of unpredicted side effects. In practice, to avoid the analysis of a huge combinatorial space for the possible sets of adjustable parameters, experience-, and intuition-based subsets of parameters are often chosen, possibly leaving some interesting counter-intuitive combinations of parameters unrevealed. The combinatorial scan of possible adjustable parameter combinations at the model optimization level is possible; however, the number of analyzed combinations is still limited. The total optimization potential (TOP) approach is…
Large strain stimulation promotes extracellular matrix production and stiffness in an elastomeric scaffold model
2016
Mechanical conditioning of engineered tissue constructs is widely recognized as one of the most relevant methods to enhance tissue accretion and microstructure, leading to improved mechanical behaviors. The understanding of the underlying mechanisms remains rather limited, restricting the development of in silico models of these phenomena, and the translation of engineered tissues into clinical application. In the present study, we examined the role of large strip-biaxial strains (up to 50%) on ECM synthesis by vascular smooth muscle cells (VSMCs) micro-integrated into electrospun polyester urethane urea (PEUU) constructs over the course of 3 weeks. Experimental results indicated that VSMC …
Discovering discriminative graph patterns from gene expression data
2016
We consider the problem of mining gene expression data in order to single out interesting features characterizing healthy/unhealthy samples of an input dataset. We present an approach based on a network model of the input gene expression data, where there is a labelled graph for each sample. To the best of our knowledge, this is the first attempt to build a different graph for each sample and, then, to have a database of graphs for representing a sample set. Our main goal is that of singling out interesting differences between healthy and unhealthy samples, through the extraction of "discriminative patterns" among graphs belonging to the two different sample sets. Differently from the other…