Pathways to achieve universal household access to modern energy by 2030

A lack of access to modern energy impacts health and welfare and impedes development for billions of people. Growing concern about these impacts has mobilized the international community to set new targets for universal modern energy access. However, analyses exploring pathways to achieve these targets and quantifying the potential costs and benefits are limited. Here, we use two modelling frameworks to analyse investments and consequences of achieving total rural electrification and universal access to clean-combusting cooking fuels and stoves by 2030. Our analysis indicates that these targets can be achieved with additional investment of US$(2005)65-86 billion per year until 2030 combined with dedicated policies. Only a combination of policies that lowers costs for modern cooking fuels and stoves, along with more rapid electrification, can enable the realization of these goals. Our results demonstrate the critical importance of accounting for varying demands and affordability across heterogeneous household groups in both analysis and policy setting. While the investments required are significant, improved access to modern cooking fuels alone can avert between 0.6 and 1.8 million premature deaths annually in 2030 and enhance wellbeing substantially

Effects of Kynurenine Pathway Inhibition on NAD+ Metabolism and Cell Viability in Human Primary Astrocytes and Neurons

The kynurenine pathway (KP) is the principle route of L-Tryptophan (TRP) metabolism, producing several neurotoxic and neuroprotective metabolic precursors before complete oxidation to the essential pyridine nucleotide nicotinamide adenine dinucleotide (NAD+). KP inhibition may prove therapeutic in central nervous system (CNS) inflammation by reducing the production of excitotoxins such as quinolinic acid (QUIN). However, KP metabolism may also be cytoprotective through the de novo synthesis of intracellular NAD+. We tested the hypothesis that the KP is directly involved in the maintenance of intracellular NAD+ levels and SIRT1 function in primary astrocytes and neurons through regulation of NAD+ synthesis. Competitive inhibition of indoleamine 2,3 dioxygenase (IDO), and quinolinic acid phosphoribosyltransferase (QPRT) activities with 1-methyl-L-Tryptophan (1-MT), and phthalic acid (PA) respectively, resulted in a dose-dependent decrease in intracellular NAD+ levels and sirtuin deacetylase-1 (SIRT1) activity, and correlated directly with reduced cell viability. These results support the hypothesis that the primary role of KP activation during neuroinflammation is to maintain NAD+ levels through de novo synthesis from TRP. Inhibition of KP metabolism under these conditions can compromise cell viability, NAD-dependent SIRT1 activity and CNS function, unless alternative precursors for NAD+ synthesis are made available

The role of research education coordinators in building research cultures in doctoral education

The development of cultures of support has become important in programmes for the preparation of research students. The paper draws on in-depth interviews with 21 research education coordinators from Australian and UK institutions to identify the strategies that they use to build research cultures and integrate research students into them. Students’ research cultures are not always linked to departmental research cultures more generally. Local contexts and conditions and staff (including supervisors’) attitudes are found to be critical in how research education coordinators respond and what is considered possible in order to ensure that research students are involved in research cultures

The design, implementation, and performance of the LZ calibration systems

LUX-ZEPLIN (LZ) is a tonne-scale experiment searching for direct dark matter interactions and other rare events. It is located at the Sanford Underground Research Facility (SURF) in Lead, South Dakota, USA. The core of the LZ detector is a dual-phase xenon time projection chamber (TPC), designed with the primary goal of detecting Weakly Interacting Massive Particles (WIMPs) via their induced low energy nuclear recoils. Surrounding the TPC, two veto detectors immersed in an ultra-pure water tank enable reducing background events to enhance the discovery potential. Intricate calibration systems are purposely designed to precisely understand the responses of these three detector volumes to various types of particle interactions and to demonstrate LZ's ability to discriminate between signals and backgrounds. In this paper, we present a comprehensive discussion of the key features, requirements, and performance of the LZ calibration systems, which play a crucial role in enabling LZ's WIMP-search and its broad science program. The thorough description of these calibration systems, with an emphasis on their novel aspects, is valuable for future calibration efforts in direct dark matter and other rare-event search experiments

New constraints on ultraheavy dark matter from the LZ experiment

Searches for dark matter with liquid xenon time projection chamber experiments have traditionally focused on the region of the parameter space that is characteristic of weakly interacting massive particles, ranging from a few GeV/c2 to a few TeV/c2. Models of dark matter with a mass much heavier than this are well motivated by early production mechanisms different from the standard thermal freeze-out, but they have generally been less explored experimentally. In this work, we present a reanalysis of the first science run of the LZ experiment, with an exposure of 0.9  tonne×yr, to search for ultraheavy particle dark matter. The signal topology consists of multiple energy deposits in the active region of the detector forming a straight line, from which the velocity of the incoming particle can be reconstructed on an event-by-event basis. Zero events with this topology were observed after applying the data selection calibrated on a simulated sample of signal-like events. New experimental constraints are derived, which rule out previously unexplored regions of the dark matter parameter space of spin-independent interactions beyond a mass of 1017  GeV/c2. Published by the American Physical Society 2024 </jats:sec

Highly-parallelized simulation of a pixelated LArTPC on a GPU

The rapid development of general-purpose computing on graphics processing units (GPGPU) is allowing the implementation of highly-parallelized Monte Carlo simulation chains for particle physics experiments. This technique is particularly suitable for the simulation of a pixelated charge readout for time projection chambers, given the large number of channels that this technology employs. Here we present the first implementation of a full microphysical simulator of a liquid argon time projection chamber (LArTPC) equipped with light readout and pixelated charge readout, developed for the DUNE Near Detector. The software is implemented with an end-to-end set of GPU-optimized algorithms. The algorithms have been written in Python and translated into CUDA kernels using Numba, a just-in-time compiler for a subset of Python and NumPy instructions. The GPU implementation achieves a speed up of four orders of magnitude compared with the equivalent CPU version. The simulation of the current induced on 10^3 pixels takes around 1 ms on the GPU, compared with approximately 10 s on the CPU. The results of the simulation are compared against data from a pixel-readout LArTPC prototype