Catalogue Search | MBRL
Are you sure you want to remove the book from the shelf?
{{itemTitle}}
12,110
result(s) for
"Simpson, J"
Sort by:
Epigenetic age prediction
Advanced age is the main common risk factor for cancer, cardiovascular disease and neurodegeneration. Yet, more is known about the molecular basis of any of these groups of diseases than the changes that accompany ageing itself. Progress in molecular ageing research was slow because the tools predicting whether someone aged slowly or fast (biological age) were unreliable. To understand ageing as a risk factor for disease and to develop interventions, the molecular ageing field needed a quantitative measure; a clock for biological age. Over the past decade, a number of age predictors utilising DNA methylation have been developed, referred to as epigenetic clocks. While they appear to estimate biological age, it remains unclear whether the methylation changes used to train the clocks are a reflection of other underlying cellular or molecular processes, or whether methylation itself is involved in the ageing process. The precise aspects of ageing that the epigenetic clocks capture remain hidden and seem to vary between predictors. Nonetheless, the use of epigenetic clocks has opened the door towards studying biological ageing quantitatively, and new clocks and applications, such as forensics, appear frequently. In this review, we will discuss the range of epigenetic clocks available, their strengths and weaknesses, and their applicability to various scientific queries. Over the past decade, the repertoire of DNA methylation‐based age predictors, known as epigenetic clocks, has grown. Here, we review four main types of epigenetic clocks that have been developed; human‐array based, reduced, composite and non‐human.
Journal Article
Long-term doubling of litter inputs accelerates soil organic matter degradation and reduces soil carbon stocks
Soil organic matter (SOM) constitutes more than two-thirds of terrestrial carbon stocks yet there are many uncertainties about the fate of soil carbon reserves with global environmental change. Moisture, altered nutrient cycles, species shifts, growing season length or rising temperatures may alter forest primary productivity and the proportions of above and belowground biomass entering soil. We investigated SOM composition using molecular-level techniques after 20 years of detrital input and removal treatment (DIRT) at the Harvard Forest. SOM biomarkers (solvent extraction, base hydrolysis and cupric(II) oxide oxidation) and nuclear magnetic resonance (NMR) spectroscopy were used to quantify changes in SOM composition and microbial activity and community composition was assessed using phospholipid fatty acid (PLFA) analysis. Doubling aboveground litter inputs decreased soil carbon content, increased the degradation of labile SOM and enhanced the sequestration of aliphatic compounds in soil. The exclusion of belowground inputs resulted in a decrease in root-derived components and enhanced the degradation of stable SOM components such as leaf-derived aliphatic structures (cutin). The DIRT manipulations resulted in soil microbial community shifts that were attributed to the accelerated processing of specific SOM components. These results collectively reveal that a detailed molecular-level characterization of SOM can provide information on SOM compositional changes and transformations after 20 years of input manipulation in a temperate forest.
Journal Article
The Oxford dictionary of modern slang
Features slang words and expressions from throughout the English-speaking world, providing a stonking good read for all word lovers and English students.
Book
Maternal exposure to polyethylene micro- and nanoplastics impairs umbilical blood flow but not fetal growth in pregnant mice
While microplastics have been recently detected in human blood and the placenta, their impact on human health is not well understood. Using a mouse model of environmental exposure during pregnancy, our group has previously reported that exposure to polystyrene micro- and nanoplastics throughout gestation results in fetal growth restriction. While polystyrene is environmentally relevant, polyethylene is the most widely produced plastic and amongst the most commonly detected microplastic in drinking water and human blood. In this study, we investigated the effect of maternal exposure to polyethylene micro- and nanoplastics on fetal growth and placental function. Healthy, pregnant CD-1 dams were divided into three groups: 10
6
ng/L of 740–4990 nm polyethylene with surfactant in drinking water (
n
= 12), surfactant alone in drinking water (
n
= 12) or regular filtered drinking water (
n
= 11). At embryonic day 17.5, high-frequency ultrasound was used to investigate the placental and fetal hemodynamic responses following exposure. While maternal exposure to polyethylene did not impact fetal growth, there was a significant effect on placental function with a 43% increase in umbilical artery blood flow in the polyethylene group compared to controls (p < 0.01). These results suggest polyethylene has the potential to cause adverse pregnancy outcomes through abnormal placental function.
Journal Article
Marine turbulence : theories, observations, and models
This text gives a comprehensive overview of measurement techniques and theories for marine turbulence and mixing processes. Written by a team of 53 world experts, the book represents a rich source of data and methods for students, scientists, and engineers in oceanography, hydrology, limnology, and meteorology.
Book
Profile-Wise Analysis: A profile likelihood-based workflow for identifiability analysis, estimation, and prediction with mechanistic mathematical models
Interpreting data using mechanistic mathematical models provides a foundation for discovery and decision-making in all areas of science and engineering. Developing mechanistic insight by combining mathematical models and experimental data is especially critical in mathematical biology as new data and new types of data are collected and reported. Key steps in using mechanistic mathematical models to interpret data include: (i) identifiability analysis; (ii) parameter estimation; and (iii) model prediction. Here we present a systematic, computationally-efficient workflow we call Profile-Wise Analysis (PWA) that addresses all three steps in a unified way. Recently-developed methods for constructing ‘profile-wise’ prediction intervals enable this workflow and provide the central linkage between different workflow components. These methods propagate profile-likelihood-based confidence sets for model parameters to predictions in a way that isolates how different parameter combinations affect model predictions. We show how to extend these profile-wise prediction intervals to two-dimensional interest parameters. We then demonstrate how to combine profile-wise prediction confidence sets to give an overall prediction confidence set that approximates the full likelihood-based prediction confidence set well. Our three case studies illustrate practical aspects of the workflow, focusing on ordinary differential equation (ODE) mechanistic models with both Gaussian and non-Gaussian noise models. While the case studies focus on ODE-based models, the workflow applies to other classes of mathematical models, including partial differential equations and simulation-based stochastic models. Open-source software on GitHub can be used to replicate the case studies.
Journal Article
Oxford dictionary of proverbs
This unique and authoritative dictionary contains over 1,100 of the most widely used proverbs in English, utilizing the latest research from Oxford Dictionaries to source them. This edition has been thoroughly revised and updated, broadening the cultural range of the proverbs selected, and covering sayings of international origins. With a strong emphasis on concisely explaining the meaning of the proverbs described, the dictionary also provides additional examples of usage, and includes a fascinating history for many entries. Arranged in A-Z order and with a useful thematic index, A Dictionary of Proverbs is ideal for browsing and perfectly suited for quick reference. Look up your old favourites, learn punchy new expressions to get your point across, and find the answer to that crossword clue. It is never too late to learn: find proverbs relevant to every aspect of life in this entertaining and informative collection.
BOOK
Soil warming and nitrogen deposition alter soil organic matter composition at the molecular-level
Rising temperatures and nitrogen (N) deposition, both aspects of global environmental change, are proposed to alter soil organic matter (SOM) biogeochemistry. For example, increased plant productivity and enhanced microbial decomposition of litter and SOM may reduce soil carbon stocks and fertility. To better understand SOM biogeochemical shifts at the molecular-level, we employed an array of biomarker and nuclear magnetic resonance (NMR) techniques to investigate the composition and degradation of SOM components in the forest floor and mineral soil horizons of warmed (5 °C above average soil temperature) and N fertilized (5 g m⁻² year⁻¹N applied in the growing season) plots from the soil warming × nitrogen addition study at the Harvard Forest, MA, USA. Biomarker analyses indicated increased plant-derived inputs into the forest floor under N fertilization. Soil warming promoted the decomposition of plant-derived aliphatic and cyclic compounds in the forest floor. Cutin degradation was observed in the heated forest floor which also exhibited relatively higher microbial activity. Lignin oxidation was also observed but was most pronounced in the mineral horizon of the heated plots. These results suggest that continued soil warming may promote the degradation of lignin- and cuticle-derived SOM. N fertilization also enhanced lignin oxidation but to a lesser extent likely due to a decline in microbial activity.¹H NMR spectra of the mineral soils revealed enrichment of plant-derived alkyl structures and microbial-derived organic matter with both soil warming and N fertilization. Overall, this study shows that the decomposition and accumulation of molecularly distinct SOM components occurs with soil warming and N amendment and may subsequently alter soil biogeochemical cycling.
Journal Article