Application of Large-Scale Synthetic Power System Models for Energy Economic Studies

Due to information confidentiality issues, there is limited access to actual power system models that represent features of actual power grids for teaching, training, and research purposes. The authors\u27 previous work describes the process of creating synthetic transmission networks, with statistics similar to those of actual power grids. Thus, this paper outlines a systematic methodology to augment the synthetic network base case for energy economic studies. The key step is to determine generator cost models by fuel type and capacity. Based on statistics summarized from the actual grids, two approaches are proposed to assign coefficients to generator cost models. To illustrate the proposed creation procedure, we describe the construction of a synthetic model for Electric Reliability Council of Texas footprint. Simulation results are presented to verify that the created test system is able to represent the behavior of actual power systems

Children's informal learning at home during COVID-19 lockdown

The national COVID-19 lockdown during school Term 1 2020 provided a unique context to investigate children’s experiences of informal, everyday learning in their household bubble. In Terms 3 and 4, 178 children in Years 4–8 from 10 primary schools agreed to participate in a group art-making activity and an individual interview about their experiences. The research adopted a strengths-based approach on the basis that most children are capable actors in their social worlds. This report documents children’s accounts of the multiple ways in which they negotiated the novel experience of forced confinement over a period of several weeks with family and whānau. The report is rich with children’s own accounts of their everyday living and learning during lockdown. To foreground children’s descriptions and explanations of their lockdown experience in this way is an acknowledgement of their right to express their views on matters of interest to them in their lives, and to have those views listened to, and acted on, by adults. Similarly, the approach reflects a growing educational research interest in student voice: enabling children to articulate their experiences so that adults can use this knowledge to better respond to and support children’s learning aspirations and needs. This research report does not speak for all children or all children’s experiences. Nevertheless, it does provide valuable insights about the phenomenon of children’s informal and everyday learning during lockdown, gained from a group of children for whom it was a mostly positive experience, and through which they learned much about themselves as persons and as members of a family and whānau. Several months after the event, children in this study were able and willing to recall their experiences of learning during lockdown. They could identify social, cultural, and historical dimensions of their learning at home. Some children were able to recount rich, detailed stories about their lockdown experience and the ways in which they organised their days and activities. For some others, their days were largely shaped for them by family and whānau members, but even so, the children were able to explain what they enjoyed, or did not, and why. Variations in children’s learning across the group highlighted the complexity of learning that each child experienced, and the importance of having social relations, environments, and contexts that encourage and support their learning. Children demonstrated an understanding and appreciation of the value of this learning.falsehttp://www.nzcer.org.nz/research/publications/learning-during-lockdownNew Zealand Council for Educational Researc

Key Technical Challenges for the Electric Power Industry and Climate Change

This paper, prepared by the Climate Change Technology Subcommittee, a subcommittee of the Power and Energy Society Energy Development and Power Generation Committee, identifies key technical issues facing the electric power industry, related to global climate change. The technical challenges arise from: 1) impacts on system operating strategies, configuration, and expansion plans of emission-reducing technologies; 2) power infrastructure response to extreme weather events; 3) effects of government policies including an expanded use of renewable and alternative energy technologies; and 4) impacts of market rules on power system operation. Possible lessons from other industries\u27 responses to climate change are explored

Agnesi Weighting for the Measure Problem of Cosmology

The measure problem of cosmology is how to assign normalized probabilities to observations in a universe so large that it may have many observations occurring at many different spacetime locations. I have previously shown how the Boltzmann brain problem (that observations arising from thermal or quantum fluctuations may dominate over ordinary observations if the universe expands sufficiently and/or lasts long enough) may be ameliorated by volume averaging, but that still leaves problems if the universe lasts too long. Here a solution is proposed for that residual problem by a simple weighting factor 1/(1+t^2) to make the time integral convergent. The resulting Agnesi measure appears to avoid problems other measures may have with vacua of zero or negative cosmological constant.Comment: 26 pages, LaTeX; discussion is added of how Agnesi weighting appears better than other recent measure

Cosmological Measures without Volume Weighting

Many cosmologists (myself included) have advocated volume weighting for the cosmological measure problem, weighting spatial hypersurfaces by their volume. However, this often leads to the Boltzmann brain problem, that almost all observations would be by momentary Boltzmann brains that arise very briefly as quantum fluctuations in the late universe when it has expanded to a huge size, so that our observations (too ordered for Boltzmann brains) would be highly atypical and unlikely. Here it is suggested that volume weighting may be a mistake. Volume averaging is advocated as an alternative. One consequence may be a loss of the argument that eternal inflation gives a nonzero probability that our universe now has infinite volume.Comment: 15 pages, LaTeX, added references for constant-H hypersurfaces and also an idea for minimal-flux hypersurface

The Born Rule Dies

The Born rule may be stated mathematically as the rule that probabilities in quantum theory are expectation values of a complete orthogonal set of projection operators. This rule works for single laboratory settings in which the observer can distinguish all the different possible outcomes corresponding to the projection operators. However, theories of inflation suggest that the universe may be so large that any laboratory, no matter how precisely it is defined by its internal state, may exist in a large number of very distantly separated copies throughout the vast universe. In this case, no observer within the universe can distinguish all possible outcomes for all copies of the laboratory. Then normalized probabilities for the local outcomes that can be locally distinguished cannot be given by the expectation values of any projection operators. Thus the Born rule dies and must be replaced by another rule for observational probabilities in cosmology. The freedom of what this new rule is to be is the measure problem in cosmology. A particular volume-averaged form is proposed.Comment: LaTeX, 16 pages, typos in Eqs. (4.3) and (6.2) correcte

In Vivo, In Vitro, and In Silico Characterization of Peptoids as Antimicrobial Agents

Bacterial resistance to conventional antibiotics is a global threat that has spurred the development of antimicrobial peptides (AMPs) and their mimetics as novel anti-infective agents. While the bioavailability of AMPs is often reduced due to protease activity, the non-natural structure of AMP mimetics renders them robust to proteolytic degradation, thus offering a distinct advantage for their clinical application. We explore the therapeutic potential of N-substituted glycines, or peptoids, as AMP mimics using a multi-faceted approach that includes in silico, in vitro, and in vivo techniques. We report a new QSAR model that we developed based on 27 diverse peptoid sequences, which accurately correlates antimicrobial peptoid structure with antimicrobial activity. We have identified a number of peptoids that have potent, broad-spectrum in vitro activity against multi-drug resistant bacterial strains. Lastly, using a murine model of invasive S. aureus infection, we demonstrate that one of the best candidate peptoids at 4 mg/kg significantly reduces with a two-log order the bacterial counts compared with saline-treated controls. Taken together, our results demonstrate the promising therapeutic potential of peptoids as antimicrobial agents

Crystal Structure of Legionella DotD: Insights into the Relationship between Type IVB and Type II/III Secretion Systems

The Dot/Icm type IVB secretion system (T4BSS) is a pivotal determinant of Legionella pneumophila pathogenesis. L. pneumophila translocate more than 100 effector proteins into host cytoplasm using Dot/Icm T4BSS, modulating host cellular functions to establish a replicative niche within host cells. The T4BSS core complex spanning the inner and outer membranes is thought to be made up of at least five proteins: DotC, DotD, DotF, DotG and DotH. DotH is the outer membrane protein; its targeting depends on lipoproteins DotC and DotD. However, the core complex structure and assembly mechanism are still unknown. Here, we report the crystal structure of DotD at 2.0 Å resolution. The structure of DotD is distinct from that of VirB7, the outer membrane lipoprotein of the type IVA secretion system. In contrast, the C-terminal domain of DotD is remarkably similar to the N-terminal subdomain of secretins, the integral outer membrane proteins that form substrate conduits for the type II and the type III secretion systems (T2SS and T3SS). A short β-segment in the otherwise disordered N-terminal region, located on the hydrophobic cleft of the C-terminal domain, is essential for outer membrane targeting of DotH and Dot/Icm T4BSS core complex formation. These findings uncover an intriguing link between T4BSS and T2SS/T3SS