Search results for "Education"

The role of spatial structure in the evolution of viral innate immunity evasion: A diffusion-reaction cellular automaton model

2020

Most viruses have evolved strategies for preventing interferon (IFN) secretion and evading innate immunity. Recent work has shown that viral shutdown of IFN secretion can be viewed as a social trait, since the ability of a given virus to evade IFN-mediated immunity depends on the phenotype of neighbor viruses. Following this idea, we investigate the role of spatial structure in the evolution of innate immunity evasion. For this, we model IFN signaling and viral spread using a spatially explicit approximation that combines a diffusion-reaction model and cellular automaton. Our results indicate that the benefits of preventing IFN secretion for a virus are strongly determined by spatial struct…

Associations between dietary polyphenols and type 2 diabetes in a cross-sectional analysis of the PREDIMED-Plus Trial: role of body mass index and sex

2019

Overweight and obesity are important risk factors for type 2 diabetes (T2D). Moving towards healthier diets, namely, diets rich in bioactive compounds, could decrease the odds of suffering T2D. However, those individuals with high body mass index (BMI) may have altered absorption or metabolism of some nutrients and dietary components, including polyphenols. Therefore, we aimed to assess whether high intakes of some classes of polyphenols are associated with T2D in a population with metabolic syndrome and how these associations depend on BMI and sex. This baseline cross-sectional analysis includes 6633 participants from the PREDIMED-Plus trial. Polyphenol intakes were calculated from food fr…

2018

Mobile genetic elements such as conjugative plasmids are responsible for antibiotic resistance phenotypes in many bacterial pathogens. The ability to conjugate, the presence of antibiotics, and ecological interactions all have a notable role in the persistence of plasmids in bacterial populations. Here, we set out to investigate the contribution of these factors when the conjugation network was disturbed by a plasmid-dependent bacteriophage. Phage alone effectively caused the population to lose plasmids, thus rendering them susceptible to antibiotics. Leakiness of the antibiotic resistance mechanism allowing Black Queen evolution (i.e. a "race to the bottom") was a more significant factor t…

Stem Cells in Pituitary Tumors: Experimental Evidence Supporting Their Existence and Their Role in Tumor Clinical Behavior

2019

Although generally benign, pituitary tumors frequently show local invasiveness and resistance to pharmacological therapy. After the demonstration of the existence of pituitary gland stem cells, over the past decade, the presence of a stem cell subpopulation in pituitary tumors has been investigated, analogous to the cancer stem cell model developed for malignant tumors. This review recapitulates the experimental evidence supporting the existence of a population of stem-like cells in pituitary tumors, focusing on their potential role in tumor initiation, progression, recurrence and resistance to pharmacological therapy.

Survival of Late Pleistocene Hunter-Gatherer Ancestry in the Iberian Peninsula

2019

The Iberian Peninsula in southwestern Europe represents an important test case for the study of human population movements during prehistoric periods. During the Last Glacial Maximum (LGM), the peninsula formed a periglacial refugium [1] for hunter-gatherers (HGs) and thus served as a potential source for the re-peopling of northern latitudes [2]. The post-LGM genetic signature was previously described as a cline from Western HG (WHG) to Eastern HG (EHG), further shaped by later Holocene expansions from the Near East and the North Pontic steppes [3, 4, 5, 6, 7, 8, 9]. Western and central Europe were dominated by ancestry associated with the ∼14,000-year-old individual from Villabruna, Italy…

Parsimonious Scenario for the Emergence of Viroid-Like Replicons De Novo

2019

This article belongs to the Special Issue Viroid-2018: International Conference on Viroids and Viroid-Like RNAs. Viroids are small, non-coding, circular RNA molecules that infect plants. Different hypotheses for their evolutionary origin have been put forward, such as an early emergence in a precellular RNA World or several de novo independent evolutionary origins in plants. Here, we discuss the plausibility of de novo emergence of viroid-like replicons by giving theoretical support to the likelihood of different steps along a parsimonious evolutionary pathway. While Avsunviroidae-like structures are relatively easy to obtain through evolution of a population of random RNA sequences of fixe…

Epigenetic mutations can both help and hinder adaptive evolution.

2015

Epigenetic variation is being integrated into our understanding of adaptation, yet we lack models on how epigenetic mutations affect evolution that includes de novo genetic change. We model the effects of epigenetic mutations on the dynamics and endpoints of adaptive walks—a process where a series of beneficial mutations move a population towards a fitness optimum. We use an individual-based model of an asexual population, where mutational effects are drawn from Fisher's geometric model. We find cases where epigenetic mutations speed adaptation or result in populations with higher fitness. However, we also find cases where they slow adaptation or result in populations with lower fitness. Th…

Population genetic structure and milk production traits in Girgentana goat breed

2017

The aim of this work was to evaluate the genetic status of the Girgentana goat, an endangered breed from Sicily (Italy), using microsatellite markers. Furthermore, as the main purpose of the Girgentana breed is milk production, quantitative milk traits were investigated, including fatty acid profile. Molecular data from CSN1S1, CSN2, CSN1S2, and CSN3 casein genes were also used to infer haplotypes. A total of 264 individuals were collected. Samples of Maltese (n = 41) and Derivata di Siria (n = 33) goat breeds were also used to understand the genetic relationship among breeds. Test-day records for milk production were collected to determine daily milk yield, fat, protein, casein, lactose, a…

Detailed analysis of inversions predicted between two human genomes: errors, real polymorphisms, and their origin and population distribution.

2016

The growing catalogue of structural variants in humans often overlooks inversions as one of the most difficult types of variation to study, even though they affect phenotypic traits in diverse organisms. Here, we have analysed in detail 90 inversions predicted from the comparison of two independently assembled human genomes: the reference genome (NCBI36/HG18) and HuRef. Surprisingly, we found that two thirds of these predictions (62) represent errors either in assembly comparison or in one of the assemblies, including 27 misassembled regions in HG18. Next, we validated 22 of the remaining 28 potential polymorphic inversions using different PCR techniques and characterized their breakpoints …

Microbiome restoration diet improves digestion, cognition and physical and emotional wellbeing

2017

Manipulating gut bacteria in the microbiome, through the use of probiotics and prebiotics, has been found to have an influence on both physical and emotional wellbeing. This study uses a dietary manipulation 'The Gut Makeover' designed to elicit positive changes to the gut bacteria within the microbiome. 21 healthy participants undertook 'The Gut Makeover' for a four week period. Weight and various aspects of health were assessed pre and post intervention using the Functional Medicine Medical Symptoms Questionnaire (MSQ). Paired sample t-tests revealed a significant reduction in self-reported weight at the end of the intervention. Adverse medical symptoms related to digestion, cognition and…