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We discuss the impact of the recent untagged analysis of B0→D⁎lν¯l decays by the Belle Collaboration on the extraction of the CKM element |Vcb| and provide updated SM predictions for the b→cτν observables R(D⁎), Pτ, and FLD⁎. The value of |Vcb| that we find is about 2σ from the one from inclusive semileptonic B decays, and is very sensitive to the slope of the form factor at zero recoil which should soon become available from lattice calculations.

Summary: By vacuolar patch-clamp and Ca2+ imaging experiments, we show that the yeast vacuolar transient receptor potential (TRPY) channel 1 is activated by cytosolic Ca2+ and inhibited by Ca2+ from the vacuolar lumen. The channel is cooperatively affected by vacuolar Ca2+ (Hill coefficient, 1.5), suggesting that it may accommodate a Ca2+ receptor that can bind two calcium ions. Alanine scanning of six negatively charged amino acid residues in the transmembrane S5 and S6 linker, facing the vacuolar lumen, revealed that two aspartate residues, 401 and 405, are essential for current inhibition and direct binding of 45Ca2+. Expressed in HEK-293 cells, a significant fraction of TRPY1, present in the plasma membrane, retained its Ca2+ sensitivity. Based on these data and on homology with TRPV channels, we conclude that D401 and D405 are key residues within the vacuolar vestibule of the TRPY1 pore that decrease cation access or permeation after Ca2+ binding. : Structural Biology; Protein Structure Aspects; Biophysics Subject Areas: Structural Biology, Protein Structure Aspects, Biophysics

Summary: Multiple sclerosis (MS) is a demyelinating disease caused by an auto-reactive immune system. Recent studies also demonstrated synapse dysfunctions in MS patients and MS mouse models. We previously observed decreased synaptic vesicle exocytosis in photoreceptor synapses in the EAE mouse model of MS at an early, preclinical stage. In the present study, we analyzed whether synaptic defects are associated with altered presynaptic Ca2+ signaling. Using high-resolution immunolabeling, we found a reduced signal intensity of Cav-channels and RIM2 at active zones in early, preclinical EAE. In line with these morphological alterations, depolarization-evoked increases of presynaptic Ca2+ were significantly smaller. In contrast, basal presynaptic Ca2+ was elevated. We observed a decreased expression of Na+/K+-ATPase and plasma membrane Ca2+ ATPase 2 (PMCA2), but not PMCA1, in photoreceptor terminals of EAE mice that could contribute to elevated basal Ca2+. Thus, complex Ca2+ signaling alterations contribute to synaptic dysfunctions in photoreceptors in early EAE.

We perform a comprehensive analysis of scalar contributions in b→cτν transitions including the latest measurements of R(D(⁎)), the q2 differential distributions in B→D(⁎)τν, the τ polarization asymmetry for B→D⁎τν, and the bound derived from the total width of the Bc meson. We find that scalar contributions with the simultaneous presence of both left- and right-handed couplings to quarks can explain the available data, specifically R(D(⁎)) together with the measured differential distributions. However, the constraints from the total Bc width present a slight tension with the current data on B→D⁎τν in this scenario, preferring smaller values for R(D⁎). We discuss possibilities to disentangle scalar new physics from other new-physics scenarios like the presence of only a left-handed vector current, via additional observables in B→D(⁎)τν decays or additional decay modes like the baryonic Λb→Λcτν and the inclusive B→Xcτν decays. We also analyze scalar contributions in b→uτν transitions, including the latest measurements of B→τν, providing predictions for Λb→pτν and B→πτν decays. The potential complementarity between the b→u and b→c sectors is finally investigated once assumptions about the flavour structure of the underlying theory are made.

The approximate symmetry of the strong interactions under isospin transformations is among the most precise tools available to control hadronic matrix elements. It is crucial in extracting fundamental parameters, but also provides avenues for the search of phenomena beyond the Standard Model. The precision of the resulting predictions requires special care when determining the quantities they are to be tested with. Specifically, in the extraction of branching ratios often isospin symmetry is assumed at one point or another implicitly, implying a significant bias for precision analyses. We extract a bias-free value for the production asymmetry between charged and neutral B meson pairs at B factories and discuss its consequences for the determination of branching fractions generally, and isospin-violating observables like the rate asymmetries in B→J/ψK or B→K⁎γ decays specifically.

To achieve the European Union's goal of climate neutrality by 2050, negative emissions may be required to compensate for emissions exceeding allocated carbon budgets. Therefore, carbon removal technologies such as bioenergy with carbon capture (BECCS) and direct air capture (DAC) may need to play a pivotal role in the power system. To design carbon removal strategies, more insights are needed into the impact of sustainable biomass availability and the feasibility of carbon capture and storage (CCS), including the expensive and energy-intensive DAC on achieving net-zero and net-negative targets. Therefore, in this study the European power system in 2050 is modelled at an hourly resolution in the cost-minimization PLEXOS modelling platform. Three climate-neutral scenarios with targets of 0, -1, and -3.9 Mt CO2/year (which agree with varying levels of climate justice) are assessed for different biomass levels, and CCS availability. Findings under baseline assumptions reveal that in a climate-neutral power system with biomass and CCS options, it is cost-effective to complement variable renewable energy with a mix of combined cycle natural gas turbines (CCNGT) for flexibility and BECCS as base load to compensate for the CO2 emissions from natural gas and additional carbon removal in the net-negative scenarios. The role of these technologies becomes more prominent, with -3.9 GtCO2/year target. Limited biomass availability necessitates additional 0.4–4 GtCO2/year DAC, 10–50 GW CCNGT with CCS, and 10–50 GW nuclear. Excluding biomass doubles system costs and increases reliance on nuclear energy up to 300 TWh/year. The absence of CCS increases costs by 78%, emphasizing significant investments in bioenergy, nuclear power, hydrogen storage, and biogas. Sensitivity analysis and limitations of the study are fully discussed.

The role of aichivirus A1 (AiV-A1) in acute gastroenteritis remains controversial and in vitro data illustrating its pathogenesis in suitable human models are scarce. Here, we demonstrate that AiV-A1 isolate A846/88 replicates in ApoA1- (absorptive) and Ki-67-positive (proliferative) enterocytes in stem cell-derived human small intestinal epithelium (HIE) as well as in patient biopsy samples, but not in any of the tested human cell lines. The infection did not result in tissue damage and did not trigger type I and type III interferon (IFN) signalling, whereas the control, human coxsackievirus B3 (strain Nancy), triggered both IFNs. To investigate the tissue tropism, we infected a human tracheal/bronchial epithelium model (HTBE) with AiV-A1 isolates A846/88 and kvgh99012632/2010 and, as a control, with rhinovirus A2 (RV-A2). AiV-A1 isolate kvgh99012632/2010, but not isolate A846/88, replicated in HTBE and induced type III IFN and ISGs signalling. By using various pharmacological inhibitors, we elaborated that cellular entry of AiV-A1 depends on clathrin, dynamin, and lipid rafts and is strongly reliant on endosome acidification. Viral particles co-localised with Rab5a-positive endosomes and promoted leakage of endosomal content. Our data shed light on the early events of AiV-A1 infection and reveal that different isolates exhibit distinct tissue tropism. This supports its clinical importance as a human pathogen with the potential to evolve toward broader tissue specificity.

The International Maritime Organization (IMO) committed to reduce by 50% the annual greenhouse gas (GHG) emissions from international shipping by 2050 compared to 2008 levels. Future low-carbon fuels use in the maritime transport to curb GHG emissions can increase freight rates and affect trade, especially for commodities transported over long distances. This study performed a case study to evaluate lignocellulosic marine biofuels use in soybean trade routes from Brazil and U.S. to China, in terms of supply volumes, GHG emissions and potential increase on freight costs. This is the first attempt to assess biofuel use in a specific product trade. To this end, two scenarios and three technologies were developed for biofuels availability from 2020 to 2050. Findings reveal that Brazil benefits from higher biofuel supply and four Brazilian biofuel pathways meet total bunker fuel demand in 2050, while U.S. pathways supplied up to 24%. However, emission reduction come at significant cost increase with abatement costs reaching more than US$ 300/tCO2e for some of the Brazilian and U.S. pathways. To reduce this cost gap, market instruments, such as carbon price of at least US$ 100/tCO2e would be required. Nevertheless, fuel cost increase has not resulted in significant cost variation between Brazilian and U.S. vessel routes. Hence, Brazilian trade routes could keep lower freight costs than U.S. even with higher biofuel shares. This indicates that regions capable of supplying low-carbon fuels can become more competitive in their exports in a decarbonized maritime trade.

Integrated assessment models (IAM) study the interlinkages between human and natural systems and play a key role in assessing global strategies to reduce global warming. However, they largely neglect the role of materials and the circular economy. With the Plastics Integrated Assessment model (PLAIA), we included plastic production, use, and end-of-life in the IAM IMAGE. PLAIA models the global plastics sector and its impacts up to 2100 for 26 world regions, providing a long-term, dynamic perspective of the sector and its interactions with other socioeconomic and natural systems. This article summarizes the model structure, mathematical formulation, assumptions, and data sources. The model links the upstream chemical production with the downstream production of plastics, their use in different sectors, and their end of life. Therefore, PLAIA can assess material use and emission mitigation strategies throughout the whole life cycle in an IAM, including the impacts of the circular economy on mitigating climate change. PLAIA projects plastics demand, production pathways and specifies the annual plastic waste generation, collection, and the impact of waste management strategies. It shows the fossil and bio-based energy and carbon flows in product stocks, landfills, and the emissions in production and at the end of life. • We included plastics production, use, and waste management into an Integrated Assessment Model (IAM). • Our model PLAIA provides a long-term, dynamic perspective of the global plastics sector until 2100 and its interactions with other sectors and the environment. • PLAIA can assess the impact of material use and emission mitigation strategies throughout the whole life cycle of plastics.

Summary: The greenhouse gas (GHG) emissions of the marine sector were around 2.6% of world GHG emissions in 2015 and are expected to increase 50%–250% to 2050 under a “business as usual” scenario, making the decarbonization of this fossil fuel-intensive sector an urgent priority. Biofuels, which come in various forms, are one of the most promising options to replace existing marine fuels for accomplishing this in the short to medium term. Some unique challenges, however, impede biofuels penetration in the shipping sector, including the low cost of the existing fuels, the extensive present-day refueling infrastructure, and the exclusion of the sector from the Paris climate agreement. To address this, it is necessary to first identify those biofuels best suited for deployment as marine fuel. In this work, the long list of possible biofuel candidates has been narrowed down to four high-potential options—bio-methanol, bio-dimethyl ether, bio-liquefied natural gas, and bio-oil. These options are further evaluated based on six criteria—cost, potential availability, present technology status, GHG mitigation potential, infrastructure compatibility, and carbon capture and storage (CCS) compatibility—via both an extensive literature review and stakeholder discussions. These four candidates turn out to be relatively evenly matched overall, but each possesses certain strengths and shortcomings that could favor that fuel under specific circumstances, such as if compatibility with existing shipping infrastructure or with CCS deployment become pivotal requirements. Furthermore, we pay particular attention to the possibility of integrating deployment of these biofuels with CCS to further reduce marine sector emissions. It is shown that this aspect is presently not on the radar of the industry stakeholders but is likely to grow in importance as CCS acceptability increases in the broader green energy sector.

Biomass is projected to play a key role in meeting global climate targets. To achieve a resource-efficient biomass use, European bioeconomy strategies increasingly consider the concept of a circular bioeconomy (CBE). We define the term CBE via a literature review and analyze the concept’s role in north-west European bioeconomy clusters through interviews. We identify strategies regarding the clusters’ feedstock and product focus, and investigate what role biorefineries, circular solutions, recycling and cascading play. Finally, we discuss gaps in CBE literature and the potential contributions of the CBE to sustainability. The analyzed bioeconomy clusters move towards a CBE by increasingly considering residues and wastes as a resource, developing integrated biorefineries and focusing more on material and high value applications of biomass. However, there is so far only little focus on the end-of-life of bio-based products, i.e. on circular product design, recycling and cascading. Key challenges for implementing circular strategies are policies and regulations, costs and the current small size of bio-based markets. Amongst the product sectors the interviewees identified as promising for the bioeconomy, plastics and construction & building materials have most recycling and cascading potential. While the CBE could contribute to improving the sustainability of the bioeconomy, the concept is not inherently sustainable and its potential trade-offs need to be addressed. Especially social aspects, cascading, circular product design, and aspects related to product use seem to be underrepresented in CBE literature, while the topics biorefinery, wastes and residues as well as waste management are significantly covered.