Converting wasteland into wonderland by earthworms—a low-cost nature’s technology for soil remediation: a case study of vermiremediation of PAHs contaminated soil

Earthworms in general are tolerant to many chemical contaminants including heavy metals and organic pollutants in soil and can bio-accumulate them in their tissues. Earthworms species like Eisenia fetida, Eisenia tetraedra, Lumbricus terrestris, Lumbricus rubellus and Allobophora chlorotica have been found to remove heavy metals (Cd, Pb, Cu, Hg, etc.) pesticides and lipophilic organic micropollutants like the polycyclic aromatic hydrocarbons (PAH) from the soil. They ‘absorb’ the dissolved chemicals through the moist ‘body wall’ in the interstitial water and also ‘ingest’ by mouth while the soil passes through the gut. They either ‘bio-transform’ or ‘biodegrade’ the chemical contaminants rendering them harmless in their bodies. Meanwhile the quality of the soil is improved significantly in terms of physical, chemical and biological properties as the worms thoroughly upturn and disperse the soil, ingest large volumes of soil and excrete nutritive materials (NKP and micronutrients) in the form of ‘vermicasts’ along with millions of beneficial soil microbes including nitrogen fixers.     

Environmental and Strategic Uncertainty in Common Property Management: The Case of Scottish Red Deer

The range of red deer populations in the Scottish Highlands can cover several different landholdings (estates), many of which derive their income primarily from the private hunting (stalking) of stags. The deer belong to nobody and their seasonal movement does not respect the boundaries of individual estates, but a 'rule of capture' does apply as, once shot, the deer become the property of the estate owner. This paper argues that deer populations would best be managed as a common property resource. Indeed, for this reason, the Deer Commission for Scotland has encouraged owners to form Deer Management Groups. These groups are now able to utilize a computer program that models the relationship between grazing quality and population dynamics. However, drawing upon examples from the Western Highlands, the paper finds that common property management must overcome incentives to behave strategically that arise from the characteristics of flow and storage of the resource. The problem is aggravated by the degradation of the habitat that has occurred over centuries. This often means that the resource is below its optimum in terms of stag numbers and quality. Scientific models are an important contribution, but only reduce the environmental uncertainty. Their full potential can only be realized if all landowners are obliged to actively engage in common property management.     

SARS-CoV2 (COVID-19) infection: is fetal surgery in times of national disasters reasonable?

Even though the global COVID-19 pandemic may affect how medical care is delivered in general, most countries try to maintain steady access for women to routine pregnancy care, including fetal anomaly screening. This means that, also during this pandemic, fetal anomalies will be detected, and that discussions regarding invasive genetic testing and possibly fetal therapy will need to take place. For patients, concerns about Severe Acute Respiratory Syndrome-Corona Virus 2 will add to the anxiety caused by the diagnosis of a serious fetal anomaly. Yet, also for fetal medicine teams the situation gets more complex as they must weigh up the risks and benefits to the fetus as well as the mother, while managing a changing evidence base and logistic challenges in their healthcare system.     

Fetal spina bifida: What we tell the parents

Worldwide, about 150 000 infants are born with spina bifida yearly, making this condition one of the most common fetal central nervous system anomalies compatible with life. Over the last decade, major changes have been introduced in the prenatal diagnosis and management of spina bifida. In this review, we provide a brief summary of the current management of fetal spina bifida and present essential information that should be provided to expecting parents when their fetus has been diagnosed with spina bifida. This information is focused around common parental questions, as encountered in our typical clinical practice, to facilitate knowledge translation.     

The influence of drainage networks on patterns of soil respiration in a desert catchment

Hydrologic flow and connectivity act as important determinants of ecological pattern and process in heterogeneous landscapes. Here we examine how the routing of water through the drainage network of an upper Sonoran Desert basin influences landscape patterns of soil respiration (SR) at both seasonal and event-based timescales. At seasonal timescales, SR varied up to 13-fold with downstream position in the drainage network, and annual estimates of CO2 efflux ranged from 185 g C x m(-2) x yr(-1) to 1190 g C x m(-2) x yr(-1) for sites arrayed along the same flow path. Spatial patterns of SR were unrelated to the carbon and water content of surface soils, but rather tracked changes in plant size and productivity, which in turn reflect downstream increases in groundwater availability. The relative importance of precipitation and temperature as drivers of SR also changed with landscape position, with the latter becoming more important in downstream locations. At the scale of individual precipitation events, SR increased up to 30-fold upon rewetting but typically returned to background levels within 24 h, even when soil moisture remained elevated. Unlike patterns observed at seasonal scales, event-based losses of CO2 varied across the landscape as a function of the organic-matter content in surface soils. Results from labile carbon amendments confirm that CO2 losses following precipitation pulses are initially constrained by substrate availability, not soil drying. By mediating spatial patterns of vegetation structure and soil resource availability, drainage networks represent an important physical template upon which belowground processes are organized in desert basins.     

A novel two-dimensional model for colloid transport in physically and geochemically heterogeneous porous media

A two-dimensional model for colloid transport in geochemically and physically heterogeneous porous media is presented. The model considers patchwise geochemical heterogeneity, which is suitable to describe the chemical variability of many surficial aquifers with ferric oxyhydroxide-coated porous matrix, as well as spatial variability of hydraulic conductivity, which results in heterogeneous flow field. The model is comprised of a transient fluid flow equation, a transient colloid transport equation, and an equation for the dynamics of colloid deposition and release. Numerical simulations were carried out with the model to investigate the colloid transport behavior in layered and randomly heterogeneous porous media. Results demonstrate that physical and geochemical heterogeneities markedly affect the colloid transport behavior. Layered physical or geochemical heterogeneity can result in distinct preferential flow paths of colloidal particles. Furthermore, the combined effect of layered physical and geochemical heterogeneity may result in enhanced or reduced preferential flow of colloids. Random distribution of physical heterogeneity (hydraulic conductivity) results in a random flow field and an irregularly distributed colloid concentration profile in the porous medium. Contrary to random physical heterogeneity, the effect of random patchwise geochemical heterogeneity on colloid transport behavior is not significant. It is mostly the mean value of geochemical heterogeneity rather than its distribution that governs the colloid transport behavior.