Search results for " complex"

Vanillin cell sensor

2007

Our project for iGEM 2006 consisted of designing a cellular vanillin biosensor. We used an EnvZ -E. coli strain as a chassis, and constructed two different devices: a sensor and an actuator, assembled using OmpR-P as a standardised mediator. The sensor device contained a computation- ally designed vanillin receptor and a synthetic two-component signal transduction protein (Trz). The receptor protein was based on a ribose-binding protein as scaffold. The Trz was built by fusion of the periplasmic and transmembrane domains of a Trg protein with an EnvZ kinase domain. When the receptor complex binds Trg, an allosteric motion is propagated to the cyto- plasmic EnvZ kinase domain, resulting in a…

DNA combinatorial messages and Epigenomics: The case of chromatin organization and nucleosome occupancy in eukaryotic genomes

2019

Abstract Epigenomics is the study of modifications on the genetic material of a cell that do not depend on changes in the DNA sequence, since those latter involve specific proteins around which DNA wraps. The end result is that Epigenomic changes have a fundamental role in the proper working of each cell in Eukaryotic organisms. A particularly important part of Epigenomics concentrates on the study of chromatin, that is, a fiber composed of a DNA-protein complex and very characterizing of Eukaryotes. Understanding how chromatin is assembled and how it changes is fundamental for Biology. In more than thirty years of research in this area, Mathematics and Theoretical Computer Science have gai…

2013

Controlling the position of the nucleus is vital for a number of cellular processes from yeast to humans. In Drosophila nurse cells, nuclear positioning is crucial during dumping, when nurse cells contract and expel their contents into the oocyte. We provide evidence that in nurse cells, continuous filopodia-like actin cables, growing from the plasma membrane and extending to the nucleus, achieve nuclear positioning. These actin cables move nuclei away from ring canals. When nurse cells contract, actin cables associate laterally with the nuclei, in some cases inducing nuclear turning so that actin cables become partially wound around the nuclei. Our data suggest that a perinuclear actin mes…

What are and what aren’t complex nominal expressions in flexible word order languages

2020

AbstractThis paper tackles the challenge of how to identify multi-word (or “complex”) nominal expressions in flexible word order languages including certain Australian languages and Vedic Sanskrit. In these languages, a weak or absent noun/adjective distinction in conjunction with flexible word order make it often hard to distinguish between complex nominal expressions, on the one hand, and cases where the nominals in question form independent expressions, on the other hand. Based on a discourse-based understanding of what it means to form a nominal expression, this paper surveys various cases where we arenotdealing with multi-word nominal expressions. This involves, in particular, peripher…

Deep neural attention-based model for the evaluation of italian sentences complexity

2020

In this paper, the Automatic Text Complexity Evaluation problem is modeled as a binary classification task tackled by a Neural Network based system. It exploits Recurrent Neural Units and the Attention mechanism to measure the complexity of sentences written in the Italian language. An accurate test phase has been carried out, and the system has been compared with state-of-art tools that tackle the same problem. The computed performances proof the model suitability to evaluate sentence complexity improving the results achieved by other state-of-the-art systems.

Multi-class Text Complexity Evaluation via Deep Neural Networks

2019

Automatic Text Complexity Evaluation (ATE) is a natural language processing task which aims to assess texts difficulty taking into account many facets related to complexity. A large number of papers tackle the problem of ATE by means of machine learning algorithms in order to classify texts into complex or simple classes. In this paper, we try to go beyond the methodologies presented so far by introducing a preliminary system based on a deep neural network model whose objective is to classify sentences into more of two classes. Experiments have been carried out on a manually annotated corpus which has been preprocessed in order to make it suitable for the scope of the paper. The results sho…

The association between muscle dysmorphia and eating disorder symptomatology: A systematic review and meta-analysis

2019

Background and aimsResearch shows inconsistent findings about the link between muscle dysmorphia (MD) and eating disorder (ED) symptomatology. The aim of this study is to synthesize the scientific evidence available on this topic, the researchers conducted a systematic review and meta-analysis.MethodsThe literature search enabled us to identify 39 published articles, which provided 36 independent estimations of the correlation between the two variables.ResultsOur analysis found a positive association between MD and ED symptoms (r+ = .36; 95% CI = 0.30, 0.41). Moderator analyses showed that the type of sample and the tools for assessing MD and ED were statistically associated with the MD–ED …

Governing Complex Strategic Networks: Emergence Versus Enabling Effects

2017

In today’s knowledge-based economy, the sources of competitive advantage increasingly lie in webs of relationships between a variety of firms and organizations that, over time, lead to the emergence of strategic networks. As the performances of both the network actors and the whole network are strictly linked with the coordination and governance of network actors and their activities, this study aims to shed light on the ways in which the processes of network coordination and governance take place. Strategic networks are here viewed as complex adaptive systems, and the twin nature of the processes of strategic network coordination and governance is examined. On one hand, I underscore the em…

The Chinese Postman Problem with Load-Dependent Costs

2018

[EN] We introduce an interesting variant of the well-known Chinese postman problem (CPP). While in the CPP the cost of traversing an edge is a constant (equal to its length), in the variant we present here the cost of traversing an edge depends on its length and on the weight of the vehicle at the moment it is traversed. This problem is inspired by the perspective of minimizing pollution in transportation, since the amount of pollution emitted by a vehicle not only depends on the travel distance but also on its load, among other factors. We define the problem, study its computational complexity, provide two mathematical programming formulations, and propose two metaheuristics for its soluti…

Can copper(II) mediate Hoogsteen base-pairing in a left-handed DNA duplex? A pulse EPR study

2010

Pulse EPR spectroscopy is sued to investigate possible structural features of the copper(II) ion coordinated to poly(dG-dC) poly(dG-dC) in a frozen aqueous solution, and the structural change of the polynucleotide induced by the presence of the metal ion. Two different copper species were identified and their geometry explained by a molecular model. According to this model, one species is exclusively coordinated to a single guanine with the N7 nitrogen atom forming a coordinative bond with the copper. In the other species, a guanine and a cytosine form a ternary complex together with the copper ion. A copper crosslink between the N7 of guanine and N3 of cytosine is proposed as the most prob…