Modelling the structure and evolution of cultural information as quasispecies.

We present a novel mode of cultural evolution whereby some forms of transmission may be modelled as quasispecies. The model incorporates the effect of high rates of error in certain forms of communication; while also building on the structural similarities between biological molecules and written language. Firstly, both written language and key biological molecules, such as RNA and proteins, are modular.

Listeria monocytogenes GlmR Is an Accessory Uridyltransferase Essential for Cytosolic Survival and Virulence.

The cytosol of eukaryotic host cells is an intrinsically hostile environment for bacteria. Understanding how cytosolic pathogens adapt to and survive in the cytosol is critical to developing novel therapeutic interventions against these pathogens. The cytosolic pathogen Listeria monocytogenes requires (previously known as ), a gene of unknown function, for resistance to cell-wall stress, cytosolic survival, inflammasome avoidance, and, ultimately, virulence .

A New Ecological and Evolutionary Perspective on the Emergence of Oxygenic Photosynthesis.

In this hypothesis article, we propose that the timing of the evolution of oxygenic photosynthesis and the diversification of cyanobacteria is firmly tied to the geological evolution of Earth in the Mesoarchean to Neoarchean. Specifically, the diversification of species capable of oxygenic photosynthesis is tied to the growth of subaerial (above sea-level/terrestrial) continental crust, which provided niches for their diversification. Moreover, we suggest that some formerly aerobic bacterial lineages evolved to become anoxygenic photosynthetic as a result of changes in selection following the reintroduction of ferruginous conditions in the oceans at 1.

Regional Features of Long-Term Exposure to PM Air Quality over Asia under SSP Scenarios Based on CMIP6 Models.

This study investigates changes in fine particulate matter (PM) concentration and air-quality index (AQI) in Asia using nine different Coupled Model Inter-Comparison Project 6 (CMIP6) climate model ensembles from historical and future scenarios under shared socioeconomic pathways (SSPs). The results indicated that the estimated present-day PM concentrations were comparable to satellite-derived data. Overall, the PM concentrations of the analyzed regions exceeded the WHO air-quality guidelines, particularly in East Asia and South Asia.

Biogeographical Modeling of Alien Worlds.

In this article, we partially quantify the biological potential of an exoplanet. We employ a variety of biogeographical analyses, placing biological evolution in the context of the geological evolution of the planet as a whole. Terrestrial (as in Earthly) biodiversity is tightly constrained in terms of species richness by its environment.

A chronology of global air quality.

Air pollution has been recognized as a threat to human health since the time of Hippocrates, 400 BC. Successive written accounts of air pollution occur in different countries through the following two millennia until measurements, from the eighteenth century onwards, show the growing scale of poor air quality in urban centres and close to industry, and the chemical characteristics of the gases and particulate matter. The industrial revolution accelerated both the magnitude of emissions of the primary pollutants and the geographical spread of contributing countries as highly polluted cities became the defining issue, culminating with the great smog of London in 1952.

The effect of future ambient air pollution on human premature mortality to 2100 using output from the ACCMIP model ensemble.

Ambient air pollution from ground-level ozone and fine particulate matter (PM) is associated with premature mortality. Future concentrations of these air pollutants will be driven by natural and anthropogenic emissions and by climate change. Using anthropogenic and biomass burning emissions projected in the four Representative Concentration Pathway scenarios (RCPs), the ACCMIP ensemble of chemistry-climate models simulated future concentrations of ozone and PM at selected decades between 2000 and 2100.

Health burdens of surface ozone in the UK for a range of future scenarios.

Exposure to surface ozone (O3), which is influenced by emissions of precursor chemical species, meteorology and population distribution, is associated with excess mortality and respiratory morbidity. In this study, the EMEP-WRF atmospheric chemistry transport model was used to simulate surface O3 concentrations at 5km horizontal resolution over the British Isles for a baseline year of 2003, for three anthropogenic emissions scenarios for 2030, and for a +5°C increase in air temperature on the 2003 baseline. Deaths brought forward and hospitalisation burdens for 12 UK regions were calculated from population-weighted daily maximum 8-hour O3.

The contribution from shipping emissions to air quality and acid deposition in Europe.

A global three-dimensional Lagrangian chemistry-transport model STOCHEM is used to describe the European regional acid deposition and ozone air quality impacts along the Atlantic Ocean seaboard of Europe, from the SO2, NOx, VOCs and CO emissions from international shipping under conditions appropriate to the year 2000. Model-derived total sulfur deposition from international shipping reaches over 200 mg S m(-2) yr(-1) over the southwestern approaches to the British Isles and Brittany. The contribution from international shipping to surface ozone concentrations during the summertime, peaks at about 6 ppb over Ireland, Brittany and Portugal.

Chromatin silencing: RNA in the driving seat.

Recent studies have provided major new insights into the mechanism by which eukaryotic organisms initiate heterochromatin formation. Surprisingly, RNA appears to be a central component of the chromatin silencing machinery.

Co-evolution of the genetic code and ribozyme replication.

The origin of translation has stimulated much discussion since the basic processes involved were deciphered during the 1960s and 1970s. One strand of thought suggested that the process originated from RNA replication in the RNA world (Weiner & Maizels, 1987, 1994). In this paper I seek to extend this model.