Particulate organic matter in artificial soils

It is estimated that around 2 ×109 hectares of land (15% of global land area) has been degraded by human activity, and rates of soil degradation are increasing. Soil is a precious resource, it sustains almost all terrestrial life and provides 90% of the food that feeds humanity. New methods are needed to improve degraded soils and recover desertified soils, particularly in higher risk areas such as deforested areas in the tropics. Waste products of industrial bio-refining may provide a convenient and abundant material for use as a soil amendment, with the added benefit of increasing the carbon sequestration potential of bio-based products. Unfortunately, knowledge of how soils can be restored in a targeted manner are missing. This thesis aims to determine the key inter-particulate interactions which promote the formation of stable aggregates, with a focus on bio-refinery products as soil amendments. New methodologies are established in order to explore particulate interactions in the context of soils, and tested on artificial soils and aggregates with defined compositions. Abiotic artificial soils are studied, to identify the physical and chemical aggregate forming processes separately of biological processes. Particulate - clay interactions are found to be complex, and the mechanical properties of the aggregate are found not only to be dependent on surface chemistry but also on the fabric morphology, pore space and particle shape. Organosolv lignin, a biorefinery waste product, was shown to bind to the silica face of kaolinite, driven by hydrophobic interactions in suspension, and were found to strengthen kaolinite aggregates up to a percolation threshold. Video image analysis is used to determine slaking kinetics of aggregates submerged in a flow cell. The role of these interactions for soil development is also investigated, in order to determine if aggregates form by accumulating stable organo-mineral interactions over repeated wet/dry cycles. The nature of lignin-kaolinite interactions are investigated using solid-state magic angle spinning NMR and T1 relaxation NMR. Finally, a soil microcosm experiment was carried out, in order to determine the microbial response to the addition of lignin, which present a challenging substrate for ecosystems of degraded soils. These experiments illustrate the importance of particulate interactions for forming stable soil aggregates and soil structure, and the results provide insights into how particulates may be engineered to improve soils with a targeted approach.Open Acces

Star Trek, Star Wars, or Battlestar Galactica—the Occurring Privatization of Space Exploration, and the Need for “Global” Regulations

Privatized space travel is not innately bad because of its commercial nature. Commercialization leads to efficient innovation; and our scientific pursuits benefit from advancements in technology in every space-related industry. This is not to say that privatized space travel is not without disgust and dissenters. As a dissenter, Buzz Aldrin questioned Elon Musk’s Mars proposal by arguing, “Well, now, when your [rocket] lands on Mars with people, is there going to be anything down there for you to live in or do?” Buzz Aldrin is not alone in his questioning of the motives behind mega corporations’ space projects. Billionaire-funded space travel can be a viable new market, but there is a balance of ideals we must maintain—that of corporate profit and innovation, and global public interests. The global community cannot allow corporate giant egos to stifle valid criticisms regarding consumer safety and the global community, including international relations and foreign policy. Until international governments rethink current ratified treaties and agreements, nations will not be able to provide the security that may sway dissenters to the side of privatized space travel. Commercial space travel is here, let’s ensure regulations can meet it halfway

Neuroprotective role of lactate in a human in vitro model of the ischemic penumbra

In patients suffering from cerebral ischemic stroke, there is an urgent need for treatments to protect stressed yet viable brain cells. Recently, treatment strategies that induce neuronal activity have been shown to be neuroprotective. Here, we hypothesized that neuronal activation might maintain or trigger the astrocyte-to-neuron lactate shuttle (ANLS), whereby lactate is released from astrocytes to support the energy requirements of ATP-starved hypoxic neurons, and this leads to the observed neuroprotection. We tested this by using a human cell based in vitro model of the ischemic penumbra and investigating whether lactate might be neuroprotective in this setting. We found that lactate transporters are involved in the neuroprotective effect mediated by neuronal activation. Furthermore, we showed that lactate exogenously administered before hypoxia correlated with neuroprotection in our cellular model. In addition, stimulation of astrocyte with consequent endogenous production of lactate resulted in neuroprotection. To conclude, here we presented evidence that lactate transport into neurons contributes to neuroprotection during hypoxia providing a potential basis for therapeutic approaches in ischemic stroke.</p

Effects of Short-Term Montmorency Powdered Tart Cherry Supplementation on Muscle Damage, Soreness Perception, Inflammation, Oxidative Stress, and Performance Surrounding Acute Bouts of Intense Endurance and Strength Exercise

The purpose of this research was to examine whether short-term ingestion of a powdered tart cherry supplement surrounding intense resistance and endurance exercise attenuates muscle soreness, while reducing markers of muscle damage, inflammation, and oxidative stress. 23 healthy, resistance-trained men (20.9±2.6 yr, 14.2±5.4% body fat, 63.9±8.6 kg FFM) were recruited for the resistance study, while 27 endurance trained runners or triathlete (21.8±3.9 yr, 15.0±6.0% body fat, 67.4±11.8 kg) men and women were examined in the endurance study. Subjects were matched based on relative maximal back squat strength or average projected race pace, age, body weight, and fat free mass. Subjects were randomly assigned to ingest, in a double blind manner, capsules containing a placebo (P) or powdered tart cherries [CherryPURE®] (TC). Participants supplemented one time daily (480 mg/d) for 10-d including the day of exercise up to 48-hr post-exercise. Resistance study subjects performed 10 sets of 10 repetitions at 70% 1-RM back squat exercise, while endurance subjects completed a half-marathon run (21.1 km) under 2-hr (111.98±11.9 min). Fasting blood samples and quadriceps muscle soreness ratings were taken pre-exercise, 60-min, 24-h, and 48-h post-exercise and analyzed by MANOVA with repeated measures. Muscle soreness perception in the vastus medialis (1/4) (p=0.10) and the vastus lateralis (1/4) (p=0.024) tended to be lower in TC over time compared to P following resistance exercise. TC induced changes in serum creatinine (p=0.03, p=0.047) and total protein (p=0.018, p=0.081) that were lower over time and smaller from pre-lift levels compared to P in trained individuals. Despite lower TAS activity pre-run in TC compared to P (endurance), changes from pre-run levels revealed a linear increase in TAS activity during recovery in TC that was statistically different from P and pre-run levels. IL-6 levels (endurance) were lower in TC compared to P over time (p=0.053). Subjects in the TC group tended to have smaller deviations from predicted race pace (p=0.091) compared to P (endurance). Short-term supplementation of Montmorency powdered tart cherries surrounding a single bout of intense exercise, appears to be an effective dietary supplement to attenuate muscle soreness and markers of muscle catabolism, while reducing inflammatory stress, better maintaining redox balance, and increasing performance in trained individuals

Representing composition, spatial structure and management intensity of European agricultural landscapes: A new typology

Comprehensive maps that characterize the variation in agricultural landscapes across Europe are lacking. In this paper we present a new Europe-wide, spatially-explicit typology and inventory of the diversity in composition, spatial structure and management intensity of European agricultural landscapes. Agricultural landscape types were characterized at a 1 k

Mapping cropland-use intensity across Europe using MODIS NDVI time series

Global agricultural production will likely need to increase in the future due to population growth, changing diets, and the rising importance of bioenergy. Intensifying already existing cropland is often considered more sustainable than converting more natural areas. Unfortunately, our understanding of cropping patterns and intensity is weak, especially at broad geographic scales. We characterized and mapped cropping systems in Europe, a region containing diverse cropping systems, using four indicators: (a) cropping frequency (number of cropped years), (b) multi-cropping (number of harvests per year), (c) fallow cycles, and (d) crop duration ratio (actual time under crops) based on the MODIS Normalized Difference Vegetation Index (NDVI) time series from 2000 to 2012. Second, we used these cropping indicators and self-organizing maps to identify typical cropping systems. The resulting six clusters correspond well with other indicators of agricultural intensity (e.g., nitrogen input, yields) and reveal substantial differences in cropping intensity across Europe. Cropping intensity was highest in Germany, Poland, and the eastern European Black Earth regions, characterized by high cropping frequency, multi-cropping and a high crop duration ratio. Contrarily, we found lowest cropping intensity in eastern Europe outside the Black Earth region, characterized by longer fallow cycles. Our approach highlights how satellite image time series can help to characterize spatial patterns in cropping intensity—information that is rarely surveyed on the ground and commonly not included in agricultural statistics: our clustering approach also shows a way forward to reduce complexity when measuring multiple indicators. The four cropping indicators we used could become part of continental-scale agricultural monitoring in order to identify target regions for sustainable intensification, where trade-offs between intensification and the environmental should be explored.Peer Reviewe