Description of n. sp. (Rhabditida: Panagrolaimidae), an Anhydrobiotic Nematode from the Namib Desert of Namibia.

n. sp. was recovered and cultured from soils collected under (pencil-bush) in the Namib Desert of Namibia, one of the driest terrestrial habitats on Earth.

Influence of Oil and Gas End-Use on Summertime Particulate Matter and Ozone Pollution in the Eastern US.

The influence of oil and gas end-use activities on ambient air quality is complex and understudied, particularly in regions where intensive end-use activities and large biogenic emissions of isoprene coincide. In these regions, vehicular emissions of nitrogen oxides (NO≡NO + NO) modulate the oxidative fate of isoprene, a biogenic precursor of the harmful air pollutants ozone, formaldehyde, and particulate matter (PM). Here, we investigate the direct and indirect influence of the end-use emissions on ambient air quality.

Global 3D rocket launch and re-entry air pollutant and CO emissions at the onset of the megaconstellation era.

Satellite megaconstellation (SMC) missions are spurring rapid growth in rocket launches and anthropogenic re-entries. These events inject pollutants and carbon dioxide (CO) in all atmospheric layers, affecting climate and stratospheric ozone. Quantification of these and other environmental impacts requires reliable inventories of emissions.

Effects of chronic stress on rat heart function following regional ischemia: a sex-dependent investigation.

Chronic psychological stress is a recognized, yet understudied risk factor for heart disease, with potential sex-specific effects. We investigated whether chronic stress triggers sex-dependent cardiac dysfunction in isolated Wistar rat hearts subjected to ischemia-reperfusion injury. The experimental cohort underwent 1 h of daily restraint stress for 4 wk versus matched controls, followed by euthanasia (sodium pentobarbital) and heart excision for ex vivo perfusion.

Unforeseen plant phenotypic diversity in a dry and grazed world.

Earth harbours an extraordinary plant phenotypic diversity that is at risk from ongoing global changes. However, it remains unknown how increasing aridity and livestock grazing pressure-two major drivers of global change-shape the trait covariation that underlies plant phenotypic diversity. Here we assessed how covariation among 20 chemical and morphological traits responds to aridity and grazing pressure within global drylands.

Kinetics and pathways of sub-lithic microbial community (hypolithon) development.

Type I hypolithons are microbial communities dominated by Cyanobacteria. They adhere to the underside of semi-translucent rocks in desert pavements, providing them with a refuge from the harsh abiotic stresses found on the desert soil surface. Despite their crucial role in soil nutrient cycling, our understanding of their growth rates and community development pathways remains limited.

The hidden oases: unveiling trophic dynamics in Namib's fog plant ecosystem.

The Namib Desert is a hyperarid coastal desert where fog is a major moisture source. We hypothesized that the fog-harvesting grass Stipagrostis sabulicola establishes an important ecological niche, termed the "Fog-Plant-Oases" (FPOs), and serves as the primary carbon source for the invertebrate community. To determine this, we measured the natural variations of the stable carbon and nitrogen isotopes (δC and δN) of invertebrates as well as that of plant biomass and belowground detritus and estimated the contributions of the fog plants in their diets.

Hotspots of biogeochemical activity linked to aridity and plant traits across global drylands.

Perennial plants create productive and biodiverse hotspots, known as fertile islands, beneath their canopies. These hotspots largely determine the structure and functioning of drylands worldwide. Despite their ubiquity, the factors controlling fertile islands under conditions of contrasting grazing by livestock, the most prevalent land use in drylands, remain virtually unknown.

The health burden of air pollution in the UK: a modelling study using updated exposure-risk associations.

Background: Long-term exposure to ambient air pollution, in particular fine particles or PM, is a leading global disease burden. PM in the UK, dominated by agricultural emissions of ammonia (NH), has been estimated to be responsible for 29 000-34 000 adult early deaths a year. These estimates use models that relate exposure to health risk that predate cohort studies that have identified a supralinear relationship between exposure and risk at relatively low PM concentrations typical of the UK (5-12 mg m).

Impact of Legislated and Best Available Emission Control Measures on UK Particulate Matter Pollution, Premature Mortality, and Nitrogen-Sensitive Habitats.

Past emission controls in the UK have substantially reduced precursor emissions of health-hazardous fine particles (PM) and nitrogen pollution detrimental to ecosystems. Still, 79% of the UK exceeds the World Health Organization (WHO) guideline for annual mean PM of 5 μg m and there is no enforcement of controls on agricultural sources of ammonia (NH). NH is a phytotoxin and an increasingly large contributor to PM and nitrogen deposited to sensitive habitats.

Grazing and ecosystem service delivery in global drylands.

Grazing represents the most extensive use of land worldwide. Yet its impacts on ecosystem services remain uncertain because pervasive interactions between grazing pressure, climate, soil properties, and biodiversity may occur but have never been addressed simultaneously. Using a standardized survey at 98 sites across six continents, we show that interactions between grazing pressure, climate, soil, and biodiversity are critical to explain the delivery of fundamental ecosystem services across drylands worldwide.

Biogeographical survey of soil microbiomes across sub-Saharan Africa: structure, drivers, and predicted climate-driven changes.

Background: Top-soil microbiomes make a vital contribution to the Earth's ecology and harbor an extraordinarily high biodiversity. They are also key players in many ecosystem services, particularly in arid regions of the globe such as the African continent. While several recent studies have documented patterns in global soil microbial ecology, these are largely biased towards widely studied regions and rely on models to interpolate the microbial diversity of other regions where there is low data coverage.

Impact of Rocket Launch and Space Debris Air Pollutant Emissions on Stratospheric Ozone and Global Climate.

Detailed examination of the impact of modern space launches on the Earth's atmosphere is crucial, given booming investment in the space industry and an anticipated space tourism era. We develop air pollutant emissions inventories for rocket launches and re-entry of reusable components and debris in 2019 and for a speculative space tourism scenario based on the recent billionaire space race. This we include in the global GEOS-Chem model coupled to a radiative transfer model to determine the influence on stratospheric ozone (O) and climate.

Nematode communities indicate diverse soil functioning across a fog gradient in the Namib Desert gravel plains.

Soil nematodes are fundamentally aquatic animals, requiring water to move, feed, and reproduce. Nonetheless, they are ubiquitous in desert soils because they can enter an anhydrobiotic state that allows them to persist when water is biologically unavailable. In the hyper-arid Namib Desert of Namibia, rain is rare, but fog routinely moves inland from the coast and supports plant and animal life.

Plant Gender Affects Soil Fungal Microbiota Associated with Welwitschia mirabilis, an Unusual Desert Gymnosperm.

In a recent study, we found a distinct soil bacterial community associated with male and female plants of the desert gymnosperm Welwitschia mirabilis. In this subsequent study, we also found that the soil fungal community associated with Welwitschia differs between male and female plants, and between unvegetated areas and the soil under plants. Site location, pH, and soil moisture also had an important influence on the composition of the fungal community.

Rapid rise in premature mortality due to anthropogenic air pollution in fast-growing tropical cities from 2005 to 2018.

Tropical cities are experiencing rapid growth but lack routine air pollution monitoring to develop prescient air quality policies. Here, we conduct targeted sampling of recent (2000s to 2010s) observations of air pollutants from space-based instruments over 46 fast-growing tropical cities. We quantify significant annual increases in nitrogen dioxide (NO) (1 to 14%), ammonia (2 to 12%), and reactive volatile organic compounds (1 to 11%) in most cities, driven almost exclusively by emerging anthropogenic sources rather than traditional biomass burning.

The Welwitschia genome reveals a unique biology underpinning extreme longevity in deserts.

The gymnosperm Welwitschia mirabilis belongs to the ancient, enigmatic gnetophyte lineage. It is a unique desert plant with extreme longevity and two ever-elongating leaves. We present a chromosome-level assembly of its genome (6.

New and Interesting Fungi. 4.

An order, family and genus are validated, seven new genera, 35 new species, two new combinations, two epitypes, two lectotypes, and 17 interesting new host and / or geographical records are introduced in this study. Validated order, family and genus: and (based on . New genera: (based on ); (based on ); (based on ); (based on ); (based on ); (based on ); (based on ).

Sub-lithic photosynthesis in hot desert habitats.

In hyper-arid soil environments, photosynthetic microorganisms are largely restricted to hypolithic (sub-lithic) habitats: i.e., on the ventral surfaces of translucent pebbles in desert pavements.

Global mortality from outdoor fine particle pollution generated by fossil fuel combustion: Results from GEOS-Chem.

The burning of fossil fuels - especially coal, petrol, and diesel - is a major source of airborne fine particulate matter (PM), and a key contributor to the global burden of mortality and disease. Previous risk assessments have examined the health response to total PM, not just PM from fossil fuel combustion, and have used a concentration-response function with limited support from the literature and data at both high and low concentrations. This assessment examines mortality associated with PM from only fossil fuel combustion, making use of a recent meta-analysis of newer studies with a wider range of exposure.

Cardioprotective Function of Green Rooibos (Aspalathus linearis) Extract Supplementation in Ex Vivo Ischemic Prediabetic Rat Hearts.

Diabetic patients develop ischemic heart disease and strokes more readily. Following an ischemic event, restoration of blood flow increases oxidative stress resulting in myocardial damage, termed ischemia/reperfusion injury. Aspalathus linearis (rooibos), rich in the antioxidant phenolic compound aspalathin, has been implicated as cardioprotective against ischemia/reperfusion injury with undefined mechanism in control rats.

Air Pollution and Climate Forcing of the Charcoal Industry in Africa.

The demand for charcoal in Africa is growing rapidly, driven by urbanization and lack of access to electricity. Charcoal production and use, including plastic burning to initiate combustion, release large quantities of trace gases and particles that impact air quality and climate. Here, we develop an inventory of current (2014) and future (2030) emissions from the charcoal supply chain in Africa that we implement in the GEOS-Chem model to quantify the contribution of charcoal to surface concentrations of PM and ozone and direct radiative forcing due to aerosols and ozone.

The 'fertile island effect' of Welwitschia plants on soil microbiota is influenced by plant gender.

Desert and semi-desert plants are often associated with a distinct soil biota under the plants and close to the root system. We aimed to understand if similar effects could be found in the taxonomically isolated desert gymnosperm Welwitschia mirabilis in the Namib Desert, and whether this island effect varied with climate and with gender of plants. We took soil cores adjacent to the plants in environments ranging from extreme desert to arid shrubland, and in nearby control sites between the plants.

Long-chain free fatty acids inhibit ischaemic preconditioning of the isolated rat heart.

We recently reported that non-preconditioned hearts from diet-induced obese rats showed, compared to controls, a significant reduction in infarct size after ischaemia/reperfusion, whilst ischaemic preconditioning was without effect. In view of the high circulating FFA concentration in diet rats, the aims of the present study were to: (i) compare the effect of palmitate on the preconditioning potential of hearts from age-matched controls and diet rats (ii) elucidate the effects of substrate manipulation on ischaemic preconditioning. Substrate manipulation was done with dichloroacetate (DCA), which enhances glucose oxidation and decreases fatty acid oxidation.