3,892 research outputs found
Understanding the magnetic resonance spectrum of nitrogen vacancy centers in an ensemble of randomly-oriented nanodiamonds
Nanodiamonds containing nitrogen vacancy (NV-) centers show promise for a
number of emerging applications including targeted in vivo imaging and
generating nuclear spin hyperpolarization for enhanced NMR spectroscopy and
imaging. Here, we develop a detailed understanding of the magnetic resonance
behavior of NV- centers in an ensemble of nanodiamonds with random crystal
orientations. Two-dimensional optically detected magnetic resonance
spectroscopy reveals the distribution of energy levels, spin populations, and
transition probabilities that give rise to a complex spectrum. We identify
overtone transitions that are inherently insensitive to crystal orientation and
give well-defined transition frequencies that access the entire nanodiamond
ensemble. These transitions may be harnessed for high-resolution imaging and
generation of nuclear spin hyperpolarization. The data are well described by
numerical simulations from the zero- to high-field regimes, including the
intermediate regime of maximum complexity. We evaluate the prospects of
nanodiamond ensembles specifically for nuclear hyperpolarization and show that
frequency-swept dynamic nuclear polarization may transfer a large amount of the
NV- center's hyperpolarization to nuclear spins by sweeping over a small region
of its spectrum.Comment: 6 pages, 5 figure
NEW MEMBERS OF THE PERTUSARIALES (ASCOMYCOTA) PROVED BY COMBINED PHYLOGENETIC ANALYSIS
New genus Marfl oraea for the “Variolaria” amara-group as well as new members of the genera Dibaeis and Ochrolechia proved by results of the combined phylogenetic analysis based on
nuclear ITS1/ITS2 portion of ribosomal nrDNA and 12S SSU mtDNA sequences are described and compared with closely related taxa. Fift een new combinations are proposed, i.e. Dibaeis yurii,
Marfl oraea albescens, M. amara, M. aspergilla, M. corallina, M. corallophora, M. erythrella, M. excludens, M. mammosa, M. ophthalmiza, M. panyrga, M. pulvinata, M. scaberula, M. subventosa and Ochrolechia dactylina. Dibaeis yurii is recorded for the fi rst time from South Korea
Complete biosynthesis of adipic acid in Saccharomyces cerevisiae
Adipic acid is an important industrial chemical that is produced in significant quantities every year. However, conventional processes for its production are not sustainable due to a heavy dependence on petroleum derived feedstocks and emission of greenhouse gases. Biotechnological production of adipic acid in a yeast host is a sustainable alternative that can overcome these issues. While many heterologous pathways have been proposed to achieve this, significant progress has been made only using the muconic acid pathway which has been implemented by many research groups in both E. coli and S. cerevisiae. However, the in vivo conversion of muconic acid to adipic acid has not been reported. In this work, we describe the isolation of a novel enzyme: 2-enoate reductase that is capable of reducing the pi bond of an alpha unsaturated carboxylic acid such as muconic acid. We have characterized the substrate profile of these novel enzymes and have identified an oxygen tolerant enoate reductase that has significant potential for adipic acid production. This enzyme was tested for muconic acid activity in S. cerevisiae and was then expressed in a muconic acid producing yeast strain to construct a yeast host that is capable of complete biosynthesis of adipic acid using glucose as the only feedstock. To our knowledge, this is the first reported yeast strain that is capable of adipic acid biosynthesis using glucose as the only feedstock. We anticipate that adipic acid production can be improved further through metabolic engineering.
Please click Additional Files below to see the full abstract
On-site and laboratory evaluations of soundscape quality in recreational urban spaces
Context: Regulations for quiet urban areas are typically based on sound level limits alone. However, the nonacoustic context may be crucial for subjective soundscape quality. Aims: This study aimed at comparing the role of sound level and nonacoustic context for subjective urban soundscape assessment in the presence of the full on-site context, the visual context only, and without context. Materials and Methods: Soundscape quality was evaluated for three recreational urban spaces by using four subjective attributes: loudness, acceptance, stressfulness, and comfort. The sound level was measured at each site and simultaneous sound recordings were obtained. Participants answered questionnaires either on site or during laboratory listening tests, in which the sound recordings were presented with or without each site’s visual context consisting of two pictures. They rated the four subjective attributes along with their preference toward eight sound sources. Results: The sound level was found to be a good predictor of all subjective parameters in the laboratory, but not on site. Although all attributes were significantly correlated in the laboratory setting, they did not necessarily covary on site. Moreover, the availability of the visual context in the listening experiment had no significant effect on the ratings. The participants were overall more positive toward natural sound sources on site. Conclusion: The full immersion in the on-site nonacoustic context may be important when evaluating overall soundscape quality in urban recreational areas. Laboratory evaluations may not fully reflect how subjective loudness, acceptance, stressfulness, and comfort are affected by sound level
A Qualitative Evaluation to Improve the Co-Parenting for Successful Kids Program
Programs aiming to help parents are often challenged in analyzing open-ended survey questions from large samples. This article presents qualitative findings collected from 1,287 participants with a child 5 years of age or younger who completed the program evaluation for the Co-Parenting for Successful Kids online program, a 4-hour education course developed by the University of Nebraska Extension. Qualitative content analysis revealed that participants found the program useful for improving their co-parenting communication skills. Participants suggested areas for improvement such as additional information for helping children cope, conflict resolution strategies, handling legal issues, and understanding how divorce impacts children based on their age. Supports and information were requested from parents in high conflict situations, including families dealing with a co-parent’s alcohol and drug abuse, domestic violence, and having an uninvolved or absent parent. Analyzing qualitative data from participants and quantifying these responses into themes offers a useful and informative way to improve and enhance an existing education program aiming to support separating or divorcing parents
Recommended from our members
Hybrid Power Plants: Status of Operating and Proposed Plants, 2024 Edition
Improving battery technology and the growth of variable renewable generation are driving a surge of interest in “hybrid” power plants that combine, for example, wind or solar generating capacity with co-located batteries. While most of the current interest involves pairing photovoltaic (PV) plants with batteries, other types of hybrid or co-located plants with wide-ranging configurations have been part of the U.S. electricity mix for decades.
This annually updated briefing tracks and maps existing hybrid or co-located plants across the United States while also synthesizing data from power purchase agreements (PPAs) and generation interconnection queues to shed light on near- and long-term development pipelines. The scope includes “co-located hybrids” that pair two or more resources (e.g., multiple types of generation and/or generation with storage) that are operated largely independently behind a single point of interconnection, and “full hybrids” that also feature coordinated operations of the co-located resources. The focus is on plants with one megawatt (MW) or more of capacity; smaller (often behind-the-meter) projects are also increasingly common, but are not included in this data synthesis.
Key findings from the latest briefing include:
-At the end of 2023, there were 469 hybrid plants (>1 MW) operating across the United States (+21% compared to the end of 2022), totaling nearly 49 GW of generating capacity (+19%) and 3.6 GW/11.1 GWh of energy storage (+59%/+67%). PV+storage plants are by far the most common, dominating in terms of plant number (288), storage capacity (7.8 GW/24.2 GWh), storage:generator capacity ratio (54%), and storage duration (3.1 hours). But there are nearly twenty other hybrid plant configurations as well, including several different fossil hybrid categories (each dominated by the fossil component) as well as wind+storage, wind+PV, wind+PV+storage, geothermal+PV, and others.
-Last year was another strong year for PV+storage hybrids in particular: 66 of the 80 hybrids added in 2023 were PV+storage. As of the end of 2023, there was roughly as much storage capacity operating within --PV+storage hybrid plants as in standalone storage plants (~7.5 GW each). In storage energy terms, however, PV+storage edged out standalone storage by ~7 GWh (24.2 GWh vs. 17.5 GWh, respectively).
-Interconnection queue data show continued strong developer interest in hybridization. At the close of 2023, there were 18% more hybrid plants—representing 33% more generating capacity—in interconnection queues across the United States than there were at the end of 2022. Solar dominates these proposed plants as well: at the close of 2023, there were 599 GW of solar capacity proposed as a hybrid (representing ~55% of all solar capacity in the queues), most typically pairing PV with battery storage. At the same time, there were 51 GW of wind capacity proposed as a hybrid (representing ~14% of all wind capacity in the queues), again most-often pairing wind with storage. Meanwhile, more than half of all storage in the queues is estimated to be part of a hybrid plant. While many of the plants proposed in the queues will not ultimately reach commercial operations, the depth of interest in hybrid plants—especially PV+storage—is notable, particularly in certain regions. For example, in CAISO, 98% of all solar capacity and 34% of all wind capacity in the queues is proposed as a hybrid.
-The report also surveys power purchase agreement (PPA) price data from a sample of operating and proposed PV+storage plants. PV+storage PPA prices have begun to increase, and “levelized storage adders” have recently increased as well to ~80/MWh-stored (assuming one full cycle per day), or ~$35/MWh-PV. Some of the recent price increase could simply reflect a trend towards higher battery:PV capacity ratios on the mainland over time (whereas this ratio is typically pegged at 1 to 1 in Hawaii), which will increase costs, all else being equal. The well-publicized impact of inflationary and supply chain pressures on prices in 2022 could also be a short-term contributor, though battery prices have more recently hit all-time lows.
For further details on these and other findings, please refer to the short PowerPoint-style briefing, which can be downloaded here. The briefing is accompanied by two data visualizations, one focused on online plants and the other on those in interconnection queues, as well as an Excel data file with details on individual plants
LEGO-Net: Learning Regular Rearrangements of Objects in Rooms
Humans universally dislike the task of cleaning up a messy room. If machines
were to help us with this task, they must understand human criteria for regular
arrangements, such as several types of symmetry, co-linearity or
co-circularity, spacing uniformity in linear or circular patterns, and further
inter-object relationships that relate to style and functionality. Previous
approaches for this task relied on human input to explicitly specify goal
state, or synthesized scenes from scratch -- but such methods do not address
the rearrangement of existing messy scenes without providing a goal state. In
this paper, we present LEGO-Net, a data-driven transformer-based iterative
method for learning regular rearrangement of objects in messy rooms. LEGO-Net
is partly inspired by diffusion models -- it starts with an initial messy state
and iteratively "de-noises'' the position and orientation of objects to a
regular state while reducing the distance traveled. Given randomly perturbed
object positions and orientations in an existing dataset of
professionally-arranged scenes, our method is trained to recover a regular
re-arrangement. Results demonstrate that our method is able to reliably
rearrange room scenes and outperform other methods. We additionally propose a
metric for evaluating regularity in room arrangements using number-theoretic
machinery.Comment: Project page: https://ivl.cs.brown.edu/projects/lego-ne
TRANSGENIC SOYBEAN PLANTS EXPRESSING ASOYBEAN HOMOLOG OF GLYCINE-RICH PROTEIN 7 (GRP7) AND EXHIBITING IMPROVED INNATE IMMUNITY
This disclosure provides for transgenic Soybean plants expressing a soybean homolog of glycine-rich protein 7 (GRP7) and exhibiting improved innate immunity and meth ods of making Such plants
TRANSGENIC SOYBEAN PLANTS EXPRESSING ASOYBEAN HOMOLOG OF GLYCINE-RICH PROTEIN 7 (GRP7) AND EXHIBITING IMPROVED INNATE IMMUNITY
This disclosure provides for transgenic Soybean plants expressing a soybean homolog of glycine-rich protein 7 (GRP7) and exhibiting improved innate immunity and meth ods of making Such plants
- …