Could resource rents finance universal access to infrastructure? A first exploration of needs and rents

It is often argued that, ethically, resource rents should accrue to all citizens. Yet, in reality, the rents from exploiting national resources are often concentrated in the hands of a few. If resource rents were to be taxed, on the other hand, substantial amounts of public money could be raised and used to cover the population's infrastructure needs, such as access to electricity, water, sanitation, communication technology and roads, which all play important roles in a nation's economic development process. Here, the authors examine to what extent existing resource rents could be used to provide universal access to these infrastructures

BECCS potential in Brazil: Achieving negative emissions in ethanol and electricity production based on sugar cane bagasse and other residues

Stabilization at concentrations consistent with keeping global warming below 2 °C above the pre-industrial level will require drastic cuts in Greenhouse Gas (GHG) emissions during the first half of the century; net negative emissions approaching 2100 are required in the vast majority of current emission scenarios. For negative emissions, the focus has been on bioenergy with carbon capture and storage (BECCS), where carbon-neutral bioenergy would be combined with additional carbon capture thus yielding emissions lower than zero. Different BECCS technologies are considered around the world and one option that deserves special attention applies CCS to ethanol production. It is currently possible to eliminate 27.7 million tonnes (Mt) of CO2 emissions per year through capture and storage of CO2 released during fermentation, which is part of sugar cane-based ethanol production in Brazil. Thus, BECCS could reduce the country’s emissions from energy production by roughly 5%. Such emissions are additional to those due to the substitution of biomass-based electricity for fossil-fueled power plants. This paper assesses the potential and cost effectiveness of negative emissions in the joint production system of ethanol and electricity based on sugar cane, bagasse, and other residues in Brazil. An important benefit is that CO2 can be captured twice along the proposed BECCS supply chain (once during fermentation and once during electricity generation). This study only considers BECCS from fermentation because capturing such CO2 is straightforward, thus potentially representing a cost-effective mitigation option for Brazil compared to other alternatives. The assessment shows that fuel prices would increase by less than 3.5% due to the adoption of BECCS from fermentation, while increasing investors’ revenues are sufficient to compensate for the investment required. With appropriate government subsidies, or by sharing BECCS costs between all car fuels and all electricity supplied by hydro and bioelectricity, the increment in ethanol and electricity prices could be less than 1% for the final consumer. Meanwhile it would supply 77.3% of all cars’ fuel (private cars) and 17.9% of all electricity in Brazil

Hexamethylcyclopentadiene: time-resolved photoelectron spectroscopy and ab initio multiple spawning simulations

Progress in our understanding of ultrafast light-induced processes in molecules is best achieved through a close combination of experimental and theoretical approaches. Direct comparison is obtained if theory is able to directly reproduce experimental observables. Here, we present a joint approach comparing time-resolved photoelectron spectroscopy (TRPES) with ab initio multiple spawning (AIMS) simulations on the MS-MR-CASPT2 level of theory. We disentangle the relationship between two phenomena that dominate the immediate molecular response upon light absorption: a spectrally dependent delay of the photoelectron signal and an induction time prior to excited state depopulation in dynamics simulations. As a benchmark molecule, we have chosen hexamethylcyclopentadiene, which shows an unprecedentedly large spectral delay of (310 \ub1 20) fs in TRPES experiments. For the dynamics simulations, methyl groups were replaced by "hydrogen atoms" having mass 15 and TRPES spectra were calculated. These showed an induction time of (108 \ub1 10) fs which could directly be assigned to progress along a torsional mode leading to the intersection seam with the molecular ground state. In a stepladder-type approach, the close connection between the two phenomena could be elucidated, allowing for a comparison with other polyenes and supporting the general validity of this finding for their excited state dynamics. Thus, the combination of TRPES and AIMS proves to be a powerful tool for a thorough understanding of ultrafast excited state dynamics in polyenes.Peer reviewed: YesNRC publication: Ye

CXCR4-directed PET/CT with [68 Ga]Ga-pentixafor in solid tumors — a comprehensive analysis of imaging findings and comparison with histopathology

Background C-X-C motif chemokine receptor 4 (CXCR4) is overexpressed in various solid cancers and can be targeted by CXCR4-directed molecular imaging. We aimed to characterize the in-vivo CXCR4 expression in patients affected with solid tumors, along with a comparison to ex-vivo findings. Methods A total 142 patients with 23 different histologically proven solid tumors were imaged with CXCR4-directed PET/CT using [68 Ga]Ga-pentixafor (total number of scans, 152). A semi-quantitative analysis of the CXCR4-positive tumor burden including maximum standardized uptake values (SUVmax) and target-to-background ratios (TBR) using blood pool was conducted. In addition, we performed histopathological staining to determine the immuno-reactive score (IRS) from patients’ tumor tissue and investigated possible correlations with SUVmax (by providing Spearman’s rho ρ). Based on imaging, we also assessed the eligibility for CXCR4-targeted radioligand therapy or non-radioactive CXCR4 inhibitory treatment (defined as more than five CXCR4-avid target lesions [TL] with SUVmax above 10). Results One hundred three of 152 (67.8%) scans showed discernible uptake above blood pool (TBR > 1) in 462 lesions (52 primary tumors and 410 metastases). Median TBR was 4.4 (1.05–24.98), thereby indicating high image contrast. The highest SUVmax was observed in ovarian cancer, followed by small cell lung cancer, desmoplastic small round cell tumor, and adrenocortical carcinoma. When comparing radiotracer accumulation between primary tumors and metastases for the entire cohort, comparable SUVmax was recorded (P > 0.999), except for pulmonal findings (P = 0.013), indicative for uniform CXCR4 expression among TL. For higher IRS, a weak, but statistically significant correlation with increased SUVmax was observed (ρ = 0.328; P = 0.018). In 42/103 (40.8%) scans, more than five TL were recorded, with 12/42 (28.6%) exhibiting SUVmax above 10, suggesting eligibility for CXCR4-targeted treatment in this subcohort. Conclusions In a whole-body tumor read-out, a substantial portion of prevalent solid tumors demonstrated increased and uniform [68 Ga]Ga-pentixafor uptake, along with high image contrast. We also observed a respective link between in- and ex-vivo CXCR4 expression, suggesting high specificity of the PET agent. Last, a fraction of patients with [68 Ga]Ga-pentixafor-positive tumor burden were rendered potentially suitable for CXCR4-directed therapy

Dem Stickstoff auf der Spur: N2O Prozesse und Nmin Dynamik nach Grünlanderneuerung

Eine weit verbreitete Maßnahme des Grünlandmanagements, die zur Beseitigung von Narbenschäden und zur Steigerung der Futterqualität in unproduktiven Grünländern angewendet wird, ist die Grünlanderneuerung. Die mechanische Bearbeitung von Grünlandböden und die dadurch gesteigerte Mineralisation durch den Abbau organischer Bodensubstanz und der alten Grasnarbe kann zu hohen N-Verlusten in Form des klimarelevanten Treibhausgases Lachgas (N2O) und/oder Nitratauswaschung (NO3-) führen. Bisher gibt es jedoch über die Dauer des beschriebenen Effektes, sowie den Einfluss unterschiedlicher Grünlanderneuerungstechniken nur wenige Informationen. Insbesondere für die nationale Treibhausgasbilanzierung ist es jedoch von Bedeutung, die Prozesse der N2O Umsetzung und ihre Quellen zu kennen und zu erfassen, da sich nur so Maßnahmen zur Emissionsminderung ableiten lassen. Zu diesem Zweck wurde ein Parzellenversuch (2013-2015) auf zwei Standorten (Plaggenesch, Anmoorgley) in der Nähe von Oldenburg (Niedersachsen) mit unterschiedlichen Erneuerungsvarianten etabliert. Als Referenzvarianten dienten: Grünlandumwandlung in Ackerland (Mais) und langjähriges Dauergrünland. Die N2O Flüsse und die Dynamik des mineralischen N (Nmin) wurden über einen Zeitraum von zwei Jahren untersucht. Zusätzlich wurden Nmin Profile (0-90 cm) genutzt, um den N-Verlust über Winter zu quantifizieren und das Risiko einer möglichen NO3- Auswaschung abzuschätzen. Obwohl die N2O Flüsse für einen kurzen Zeitraum (2 Monate) nach der Bearbeitung erhöht waren, konnte kein Jahreseffekt festgestellt werden. Im ersten Winter nach dem Aufbrechen der alten Grasnarbe trat jedoch für den Plaggenesch ein erhöhtes Risiko für NO3- Auswaschung auf. Die Untersuchung der N2O-Produktionswege und der N2O-Reduktion zu N2 (dem Endprodukt der Denitrifikation) erfolgte unter Nutzung stabiler Isotope. Hierzu wurde die 15N-Gasflussmethode im Sommer 2014 angewendet (1). Zusätzlich wurden natürlich vorhandene stabile Isotopensignaturen im bodenbürtigen N2O (δ15NbulkN2O, δ18ON2O und δ15NSPN2O = intramolekulare Verteilung von 15N im N2O Molekül) genutzt, um Quellen der N2O-Bildung im ersten Jahr nach Grünlanderneuerung (2013-2014) zu ermitteln. Auf dem Anmoorgley wurden große N-Verluste durch den Prozess der Denitrifikation bestimmt, wobei N2 die Emissionen dominerte. Für den Plaggenesch konnten generell geringere gasförmige Verluste festgestellt werden

Crop rotations with and without legumes: a review

Leguminosen sind im ökologischen Landbau aufgrund ihrer Fähigkeit zur Luftstickstofffixierung unverzichtbar für die Stickstoffversorgung der Ackerkulturen und die Proteinversorgung der Nutztiere. Im konventionellen Anbau bieten Leguminosen die Möglichkeit, die häufig getreideintensiven Fruchtfolgen aufzulockern. Eine der wichtigsten Wirkungen dieses Break-crop-Effekts ist das Durchbrechen des Lebenszyklus von fruchtartenspezifischen Pathogenen und der damit verbundenen Einsparung von Pflanzenschutzmitteln. Die vorliegende Übersichtsarbeit stellt den derzeitigen Stand des Wissens zu Fruchtfolgen mit und ohne Leguminosen zusammen. Dabei werden ackerbauliche, ökologische und ökonomische Wirkungen des Anbaus groß- und kleinkörnig Leguminosenarten als Haupt- oder Zwischenfrüchte bzw. Unter­saaten oder als Komponenten in Gemengen dar­gestellt und bewertet. Der Schwerpunkt liegt dabei auf relevanten Publikationen in wissenschaftlichen Journalen sowie Praxis- und Forschungsberichten der Jahre 2010 – 2020 die in Deutschland oder vergleichbaren klimatischen Bedingungen durchgeführt wurden. Abschließend wird daraus der notwendige Forschungsbedarf für die Themenbereiche Pflanzenbau (konventionell und ökologisch), Pflanzenschutz, Ökonomie, Ökologie und Klimaschutz abgeleitet.In organic farming, legumes are indispensable for the nitro­gen supply of arable crops and the protein supply of livestock due to their ability to fix atmospheric nitrogen. In conventional farming, legumes offer the potential to break the often cereal-intensive crop rotations. One of the most important consequences of the break-crop effect is the interruption of the life cycle of crop-specific pathogens and the associated savings of pesticides. This review summarizes the current state of knowledge on crop rotations with and without legumes. It presents and evaluates the agronomic, ecological and economic effects of the cultivation of large- and small-seeded legume species as main or catch crops, when undersown in other crops, or used as components in mixtures. The focus is on relevant publications in scientific journals as well as practice and research reports published between 2010 and 2020 which were carried out in Germany or under comparable climatic conditions. Finally, essential research needs in the areas of crop production (conventional and organic), crop protection, economics, ecology, and climate protection are identified

Research priorities for negative emissions

Carbon dioxide removal from the atmosphere (CDR)—also known as ‘negative emissions’—features prominently in most 2 °Cscenarios and has been under increased scrutiny by scientists, citizens, and policymakers. Critics argue that ‘negative emission technologies’ (NETs) are insufficiently mature to rely on them for climate stabilization. Some even argue that 2 °Cis no longer feasible or might have unacceptable social and environmental costs. Nonetheless, the Paris Agreement endorsed an aspirational goal of limiting global warming to even lower levels, arguing that climate impacts— especially for vulnerable nations such as small island states—will be unacceptably severe in a 2 °C world. While there are few pathways to 2 °Cthat do not rely on negative emissions, 1.5 °Cscenarios are barely conceivable without them. Building on previous assessments of NETs, we identify some urgent research needs to provide a more complete picture for reaching ambitious climate targets, and the role that NETs can play in reaching them