Search results for "genetics [Transcriptome]"
showing 10 items of 3033 documents
Isotope dependence of the Zeeman effect in lithium-like calcium
2016
The magnetic moment μ of a bound electron, generally expressed by the g-factor μ=−g μB s ħ−1 with μB the Bohr magneton and s the electron's spin, can be calculated by bound-state quantum electrodynamics (BS-QED) to very high precision. The recent ultra-precise experiment on hydrogen-like silicon determined this value to eleven significant digits, and thus allowed to rigorously probe the validity of BS-QED. Yet, the investigation of one of the most interesting contribution to the g-factor, the relativistic interaction between electron and nucleus, is limited by our knowledge of BS-QED effects. By comparing the g-factors of two isotopes, it is possible to cancel most of these contributions an…
Self-organization of active particles by quorum sensing rules
2018
Many microorganisms regulate their behaviour according to the density of neighbours. Such quorum sensing is important for the communication and organisation within bacterial populations. In contrast to living systems, where quorum sensing is determined by biochemical processes, the behaviour of synthetic active particles can be controlled by external fields. Accordingly they allow to investigate how variations of a density-dependent particle response affect their self-organisation. Here we experimentally and numerically demonstrate this concept using a suspension of light-activated active particles whose motility is individually controlled by an external feedback-loop, realised by a particl…
Organic coating on biochar explains its nutrient retention and stimulation of soil fertility
2017
Amending soil with biochar (pyrolized biomass) is suggested as a globally applicable approach to address climate change and soil degradation by carbon sequestration, reducing soil-borne greenhouse-gas emissions and increasing soil nutrient retention. Biochar was shown to promote plant growth, especially when combined with nutrient-rich organic matter, e.g., co-composted biochar. Plant growth promotion was explained by slow release of nutrients, although a mechanistic understanding of nutrient storage in biochar is missing. Here we identify a complex, nutrient-rich organic coating on co-composted biochar that covers the outer and inner (pore) surfaces of biochar particles using high-resoluti…
Yeast Life Span and its Impact on Food Fermentations
2019
Yeasts are very important microorganisms for food production. The high fermentative capacity, mainly of the species of the genus Saccharomyces, is a key factor for their biotechnological use, particularly to produce alcoholic beverages. As viability and vitality are essential to ensure their correct performance in industry, this review addresses the main aspects related to the cellular aging of these fungi as their senescence impacts their proper functioning. Laboratory strains of S. cerevisiae have proven a very successful model for elucidating the molecular mechanisms that control life span. Those mechanisms are shared by all eukaryotic cells. S. cerevisiae has two models of aging, replic…
Compromised nuclear envelope integrity drives TREX1-dependent DNA damage and tumor cell invasion
2021
Although mutations leading to a compromised nuclear envelope cause diseases such as muscular dystrophies or accelerated aging, the consequences of mechanically induced nuclear envelope ruptures are less known. Here, we show that nuclear envelope ruptures induce DNA damage that promotes senescence in non-transformed cells and induces an invasive phenotype in human breast cancer cells. We find that the endoplasmic reticulum (ER)-associated exonuclease TREX1 translocates into the nucleus after nuclear envelope rupture and is required to induce DNA damage. Inside the mammary duct, cellular crowding leads to nuclear envelope ruptures that generate TREX1-dependent DNA damage, thereby driving the …
Molecular regulation of lifespan extension in fertile ant workers.
2021
The evolution of sociality in insects caused a divergence in lifespan between reproductive and non-reproductive castes. Ant queens can live for decades, while most workers survive only weeks to a few years. In most organisms, longevity is traded-off with reproduction, but in social insects, these two life-history traits are positively linked. Once fertility is induced in workers, e.g. by queen removal, worker lifespan increases. The molecular regulation of this positive link between fecundity and longevity and generally the molecular underpinnings of caste-specific senescence are not well understood. Here, we investigate the transcriptomic regulation of lifespan and reproduction in fat bod…
Chaperonopathies of senescence and the scrambling of interactions between the chaperoning and the immune systems
2010
Aging entails progressive deterioration of molecules and supramolecular structures, including Hsp chaperones and their complexes, paralleled by functional decline. Recent research has changed our views on Hsp chaperones. They work inside and outside cells in many locations, alone or forming teams, interacting with cells, receptors, and molecules that are not chaperones, in roles that are not typically attributed to chaperones, such as protein folding. Hsp chaperones form a physiological system with a variety of functions and interactions with other systems, for example, the immune system. We propose that chaperone malfunctioning due to structural damage or gene dysregulation during aging ha…
A Study of the Simulated Evolution of the Spectral Sensitivity of Visual Agent Receptors
2001
In this article we study a model for the evolution of the spectral sensitivity of visual receptors for agents in a continuous virtual environment. The model uses a genetic algorithm (GA) to evolve the agent sensors along with the control of the agents by requiring the agents to solve certain tasks in the simulation environment. The properties of the evolved sensors are analyzed for different scenarios. In particular, it is shown that the GA is able to find a balance between sensor costs and agent performance in such a way that the spectral sensor sensitivity reflects the emission spectrum of the target objects and that the capability of the sensors to evolve can help the agents significantl…
Altered host behaviour and brain serotonergic activity caused by acanthocephalans: evidence for specificity
2006
Manipulative parasites can alter the phenotype of intermediate hosts in various ways. However, it is unclear whether such changes are just by-products of infection or adaptive and enhance transmission to the final host. Here, we show that the alteration of serotonergic activity is functionally linked to the alteration of specific behaviour in the amphipodGammarus pulexinfected with acanthocephalan parasites.Pomphorhynchus laevisand, to a lesser extent,Pomphorhynchus tereticollisaltered phototactism, but not geotactism, inG. pulex, whereas the reverse was true forPolymorphus minutus. Serotonin (5-hydroxytryptamine, 5-HT) injected to uninfectedG. pulexmimicked the altered phototactism, but ha…
Streptococcus agalactiae and Chlamydia trachomatis detection in women without symptoms of infection.
2020
Background Chlamydia trachomatis (C. trachomatis) and Streptococcus agalactiae (GBS) may be present in the female cervical canal without any symptoms of infection. Chronic chlamydial infections lead to many serious complications and perinatal infections, while the presence of GBS is a reservoir for infections of newborns or invasive streptococcal infection in adults. Objectives To examine healthy women for C. trachomatis without symptoms from the reproductive system, assess the frequency of asymptomatic infections, detect GBS in the cervical canal, demonstrate differences in drug susceptibility, and determine the serotype of S. agalactiae strains and correlations among the ones present in t…