Cost optimal scenarios derived from models of a highly renewable electricity system depend on the specific input data, cost assumptions and system constraints. Here this influence is studied using a ...techno-economic optimisation model for a networked system of 30 European countries, taking into account the capacity investment and operation of wind, solar, hydroelectricity, natural gas power generation, transmission, and different storage options. A considerable robustness of total system costs to the input weather data and to moderate changes in the cost assumptions is observed. Flat directions in the optimisation landscape around cost-optimal configurations often allow system planners to choose between different technology options without a significant increase in total costs, for instance by replacing onshore with offshore wind power capacity in case of public acceptance issues. Exploring a range of carbon dioxide emission limits shows that for scenarios with moderate transmission expansion, a reduction of around 57% compared to 1990 levels is already cost optimal. For stricter carbon dioxide limits, power generated from gas turbines is at first replaced by generation from increasing renewable capacities. Non-hydro storage capacities are only built for low-emission scenarios, in order to provide the necessary flexibility to meet peaks in the residual load.
•Influence of input data and assumptions for a highly-renewable scenario are studied.•System costs are robust to input weather data and moderate cost assumption changes.•Onshore wind can be replaced by offshore at low cost if there is enough national transmission.•As carbon dioxide limits are tightened, costs rise only slowly if there is grid capacity.•Storage is economic above 80% renewables; without storage 99.9% is possible, but costs double.
New online technologies have brought with them a great promise of freedom. The computer and particularly the Internet have been represented as enabling technologies, turning consumers into users and ...users into producers. Furthermore, lay people and amateurs have been enthusiastically greeted as heroes of the digital era. This thoughtful study casts a fresh light on the shaping of user participation in the context of, among others, popular discourse in and around new media.Schäfer’s groundbreaking research into hacking, fan communities and Web 2.0 applications demonstrates how the dynamic of innovation, control and interaction have shifted the boundaries of the traditional culture industry into the user domain. The media industry undergoes a shift from creating content to providing platforms for user driven social interactions and user-generated content. In this extended culture industry, participation unfolds not only in the co-creation of media content and software-based products, but also in the development and defense of distinctive media practices that represent a socio-political understanding of new technologies.
We implement a two-qubit logic gate between a ^{43}Ca^{+} hyperfine qubit and a ^{88}Sr^{+} Zeeman qubit. For this pair of ion species, the S-P optical transitions are close enough that a single ...laser of wavelength 402 nm can be used to drive the gate but sufficiently well separated to give good spectral isolation and low photon scattering errors. We characterize the gate by full randomized benchmarking, gate set tomography, and Bell state analysis. The latter method gives a fidelity of 99.8(1)%, comparable to that of the best same-species gates and consistent with known sources of error.
For a sustainable development of the energy sector - in the future - an additional potential of energetic flexibility as well as storage capacities will be required to compensate for fluctuating ...renewable energy production. The operation of energy systems will change and flexibility in energy generation and consumption will rise to become a valuable asset. Wastewater treatment plants (WWTPs) with anaerobic sludge digestion are capable of providing that needed flexibility, not only with their energy generators but also in terms of their energy consuming aggregates on the plant. Under these circumstances a methodical approach has been developed that can be used to select, evaluate and safely implement typical aggregates on WWTPs for flexible plant operation and the provision of energetic flexibility. Relevant key figures have been developed that reconcile requirements of the purification processes with technical-physical necessities as well as the demands of the energy market. Furthermore, restrictions and control parameters have been established which complement the developed key figures to ensure effluent quality. It was demonstrated that WWTPs are able to adapt their operation mode to external and internal requirements under controlled conditions. The existing flexibility is suitable for a variety of uses, and WWTPs in general are able to participate in today's and in future energy supply products and new business models. The results show that WWTPs have a significant potential to produce renewable energy and to provide energetic flexibility, which is needed to stabilize future renewable-energy-driven energy grids.
The data collected along a metadynamics simulation can be used to recover information about the underlying unbiased system by means of a reweighting procedure. Here, we analyze the behavior of ...several reweighting techniques in terms of the quality of the reconstruction of the underlying unbiased free energy landscape in the early stages of the simulation and propose a simple reweighting scheme that we relate to the other techniques. We then show that the free energy landscape reconstructed from reweighted data can be more accurate than the negative bias potential depending on the reweighting technique, the stage of the simulation, and the adoption of well-tempered or standard metadynamics. While none of the tested reweighting techniques from the literature provides the most accurate results in all the analyzed situations, the one proposed here, in addition to helping simplifying the reweighting procedure, converges quickly and precisely to the underlying free energy surface in all the considered cases, thus allowing for an efficient use of limited simulation data.
ABSTRACT
We present constraints on Horndeski gravity from a combined analysis of cosmic shear, galaxy–galaxy lensing and galaxy clustering from $450\, \mathrm{deg}^2$ of the Kilo-Degree Survey and ...the Galaxy And Mass Assembly survey.The Horndeski class of dark energy/modified gravity models includes the majority of universally coupled extensions to ΛCDM with one scalar field in addition to the metric. We study the functions of time that fully describe the evolution of linear perturbations in Horndeski gravity. Our results are compatible throughout with a ΛCDM model. By imposing gravitational wave constraints, we fix the tensor speed excess to zero and consider a subset of models including, e.g. quintessence and f(R) theories. Assuming proportionality of the Horndeski functions αB and αM (kinetic braiding and the Planck mass run rate, respectively) to the dark energy density fraction ΩDE(a) = 1 − Ωm(a), we find for the proportionality coefficients $\hat{\alpha }_\mathrm{ B} = 0.20_{-0.33}^{+0.20} \,$ and $\, \hat{\alpha }_\mathrm{ M} = 0.25_{-0.29}^{+0.19}$. Our value of $S_8 \equiv \sigma _8 \sqrt{\Omega _{\mathrm{m}}/0.3}$ is in better agreement with the Planck estimate when measured in the enlarged Horndeski parameter space than in a pure ΛCDM scenario. In our joint three-probe analysis, we report a downward shift of the S8 best-fitting value from the Planck measurement of $\Delta S_8 = 0.016_{-0.046}^{+0.048}$ in Horndeski gravity, compared to $\Delta S_8 = 0.059_{-0.039}^{+0.040}$ in ΛCDM. Our constraints are robust to the modelling uncertainty of the non-linear matter power spectrum in Horndeski gravity. Our likelihood code for multiprobe analysis in both ΛCDM and Horndeski gravity is publicly available at https://github.com/alessiospuriomancini/KiDSHorndeski.
A new series of bispecific radioligands (BRLs) targeting prostate-specific membrane antigen (PSMA) and gastrin releasing peptide receptor (GRPr), both expressed on prostate cancer cells, was ...developed. Their design was based on the bombesin (BN) analogue, H2N-PEG2-d-Tyr6,β-Ala11,Thi13,Nle14BN(6–14), which binds to GRPr with high affinity and specificity, and the peptidomimetic urea-based pseudoirreversible inhibitor of PSMA, Glu-ureido-Lys. The two pharmacophores were coupled through copper(I)-catalyzed azide–alkyne cycloaddition to the bis(tetrafluorophenyl) ester of the chelating agent HBED-CC via amino acid linkers made of positively charged His (H) and negatively charged Glu (E): -(HE) n - (n = 0–3). The BRLs were labeled with 68Ga, and their preliminary pharmacological properties were evaluated in vitro (competitive and time kinetic binding assays) on prostate cancer (PC-3, LNCaP) and rat pancreatic (AR42J) cell lines and in vivo by biodistribution and small animal PET imaging studies in both normal and tumor-bearing mice. The IC50/K i values determined for all BRLs essentially matched those of the respective monomers. The maximal cellular uptake of the BLRs was observed between 20 and 30 min. The BRLs showed a synergistic ability in vivo by targeting both PSMA (LNCaP) and GRPr (PC-3) positive tumors, whereas the charged -(HE) n - (n = 1–3) linkers significantly reduced the kidney and spleen uptake. The bispecific (PSMA and GRPr) targeting ability and optimized pharmacokinetics of the compounds developed in this study could lead to their future application in clinical practice as more sensitive radiotracers for noninvasive imaging of prostate cancer (PCa) by PET/CT and PET/MRI.
The Fourth IPCC Assessment Report concluded that ice sheet flow models, in their current state, were unable to provide accurate forecast for the increase of polar ice sheet discharge and the ...associated contribution to sea level rise. Since then, the glaciological community has undertaken a huge effort to develop and improve a new generation of ice flow models, and as a result a significant number of new ice sheet models have emerged. Among them is the parallel finite-element model Elmer/Ice, based on the open-source multi-physics code Elmer. It was one of the first full-Stokes models used to make projections for the evolution of the whole Greenland ice sheet for the coming two centuries. Originally developed to solve local ice flow problems of high mechanical and physical complexity, Elmer/Ice has today reached the maturity to solve larger-scale problems, earning the status of an ice sheet model. Here, we summarise almost 10 yr of development performed by different groups. Elmer/Ice solves the full-Stokes equations, for isotropic but also anisotropic ice rheology, resolves the grounding line dynamics as a contact problem, and contains various basal friction laws. Derived fields, like the age of the ice, the strain rate or stress, can also be computed. Elmer/Ice includes two recently proposed inverse methods to infer badly known parameters. Elmer is a highly parallelised code thanks to recent developments and the implementation of a block preconditioned solver for the Stokes system. In this paper, all these components are presented in detail, as well as the numerical performance of the Stokes solver and developments planned for the future.
Purpose
The prostate-specific membrane antigen (PSMA) targeted positron-emitting-tomography (PET) tracer
68
Ga-PSMA-11 shows great promise in the detection of prostate cancer. However,
68
Ga has ...several shortcomings as a radiolabel including short half-life and non-ideal energies, and this has motivated consideration of
18
F-labelled analogs.
18
F-PSMA-1007 was selected among several
18
F-PSMA-ligand candidate compounds because it demonstrated high labelling yields, outstanding tumor uptake and fast, non-urinary background clearance. Here, we describe the properties of
18
F-PSMA-1007 in human volunteers and patients.
Methods
Radiation dosimetry of
18
F-PSMA-1007 was determined in three healthy volunteers who underwent whole-body PET-scans and concomitant blood and urine sampling. Following this, ten patients with high-risk prostate cancer underwent
18
F-PSMA-1007 PET/CT (1 h and 3 h p.i.) and normal organ biodistribution and tumor uptakes were examined. Eight patients underwent prostatectomy with extended pelvic lymphadenectomy. Uptake in intra-prostatic lesions and lymph node metastases were correlated with final histopathology, including PSMA immunostaining.
Results
With an effective dose of approximately 4.4–5.5 mSv per 200–250 MBq examination,
18
F-PSMA-1007 behaves similar to other PSMA-PET agents as well as to other
18
F-labelled PET-tracers. In comparison to other PSMA-targeting PET-tracers,
18
F-PSMA-1007 has reduced urinary clearance enabling excellent assessment of the prostate. Similar to
18
F-DCFPyL and with slightly slower clearance kinetics than PSMA-11, favorable tumor-to-background ratios are observed 2–3 h after injection. In eight patients, diagnostic findings were successfully validated by histopathology.
18
F-PSMA-1007 PET/CT detected 18 of 19 lymph node metastases in the pelvis, including nodes as small as 1 mm in diameter.
Conclusion
18
F-PSMA-1007 performs at least comparably to
68
Ga-PSMA-11, but its longer half-life combined with its superior energy characteristics and non-urinary excretion overcomes some practical limitations of
68
Ga-labelled PSMA-targeted tracers.
PDF
