2,034 research outputs found
A Radioelement Analysis Of The Northern Black Hills, South Dakota, U.S.A.
The uranium, thorium, and potassium contents from 736 samples, within a 15-km radius of the Homestake Gold Mine and Sanford Underground Research Facility in the Northern Black Hills indicate the geoneutrino background may be higher than average for the continental crust. The radioactive element contents of igneous, metamorphic, and sedimentary rocks were determined by gamma ray spectrometry. Many rocks show hydrothermal and metamorphic alteration within the last ten Ma of the Tertiary period. Young alkali rich igneous rocks, such as rhyolite, phonolite and other volcanic rocks, have lower than average Th:U ratios. The radioelement content of 215 igneous rocks were determined. The radioelement contents of 143 metamorphic rocks were determined. This study also shows that metamorphic rocks were found to have low variable U:Th content when compared to content in igneous rocks. Sedimentary rocks, in general, have low U, Th, and K content. The radioelement content of 236 sedimentary rocks were determined.
Rocks present within the Homestake Gold Mine, are highly altered by hydrothermal and metamorphic activity, enriching U, and in some areas, Th content. The Homestake Gold Mine lies almost entirely within metamorphic rocks. Igneous rocks occur in the mine as veins and dikes. The dominant igneous rock present is rhyolite. Metamorphic rocks present inside the HGM, were divided by formation; Ellison Fm, Poorman Fm, Yates Unit [lower Poorman Fm], Homestake Fm, and Flagrock Fm. The finding of high radioelement content in the rocks suggests that the antineutrinos background at the HGM will need to be considered and calibrated for, in future experiments conducted at the Sanford Underground Research Facility. A geoneutrino luminosity of 1.26x105 (mg-1s-1) was calculated from the samples analyzed within the Homestake Gold Mine. A total geoneutrino luminosity of 4.44x105 (mg-1s=1) was calculated from the sum of all analyses conducted in the Northern Black Hills
Probing context-dependent errors in quantum processors
Gates in error-prone quantum information processors are often modeled using
sets of one- and two-qubit process matrices, the standard model of quantum
errors. However, the results of quantum circuits on real processors often
depend on additional external "context" variables. Such contexts may include
the state of a spectator qubit, the time of data collection, or the temperature
of control electronics. In this article we demonstrate a suite of simple,
widely applicable, and statistically rigorous methods for detecting context
dependence in quantum circuit experiments. They can be used on any data that
comprise two or more "pools" of measurement results obtained by repeating the
same set of quantum circuits in different contexts. These tools may be
integrated seamlessly into standard quantum device characterization techniques,
like randomized benchmarking or tomography. We experimentally demonstrate these
methods by detecting and quantifying crosstalk and drift on the publicly
accessible 16-qubit ibmqx3.Comment: 11 pages, 3 figures, code and data available in source file
Managing complex systems: an interdisciplinary approach to modelling the effect of social and ecological interactions on carbon storage in blanket peatlands.
Peatlands are globally important for carbon storage, water quality and biodiversity. However,
many have been degraded by land use, and efforts to conserve or restore them are often contested
by stakeholders with different objectives. Peat accumulates as a result of a complex network of
interactions, which makes it challenging to predict the impact of climate and land use. Stakeholdersâ
knowledge may help to provide insights into these interactions and into the issues that underpin
conflict. To investigate the impact of social and ecological factors on blanket peatland carbon
storage, an interdisciplinary approach was used to couple cognitive and peatland development
models.
Blanket peatland stakeholders developed fuzzy cognitive maps based on their perceptions of
peatland interactions, which they validated to agree on the structure of an aggregate network. To
explore the impact of landâuse objectives on carbon stocks, stakeholders proposed changes to a set
of factors that controlled the state of the network. The changes identified to improve carbon storage
and water quality had a positive effect on carbon stored, but those that were proposed to support
local livelihoods had no effect on carbon. This was partly because some stakeholders perceived
that supporting livelihoods was incompatible with measures that were likely to result in shallower
water tables. However, further discussions between stakeholders suggested that landâuse objectives
could complement each other.
To enrich the results of the network model, the DigiBog peatland model was modified to
simulate blanket peat accumulation. Using two factors from the cognitive model, climate change
and gully blocking, two novel modelling studies were produced. The first showed that existing
peatland development models may overestimate peat accumulation because they aggregate climate
variables into annual rather than weekly inputs; the second, that gully blocking is needed to arrest
peat losses from oxidation in gullied systems, but that these losses would not be recovered 200
years after gully blocking.
The combination of both cognitive and processâbased modelling provides an example of how
stakeholder knowledge can be incorporated into simulations of complex ecosystems which is likely
to be applicable to other socialâecological systems where land use is contested. In this case, doing
so provided holistic insights into how stakeholdersâ perceptions, and the impacts of climatic forcing
and restoration, affect carbon storage in blanket peatlands
Resilience and Degradation in a Tropical Wetland Overgrazed by Cattle
The Pantanal, one of the largest wetlands in the world, is highly valued for its diversity of flora and fauna, and the dynamic hydrological regime, combined with heterogeneous topography, has resulted in a mosaic of diverse habitats types in terms of species and physical structure. However, the Pantanal floodplains are also important for beef cattle production due to the abundance of forage resources. Cattle prefer grazing near water bodies because these areas have high quality forage as a result of flooding regimes (Santos et al. 2002). Many wetlands go through a wet/dry cycle that is essential to maintain their productivity and function. In drier years, wetland drawdown provides optimal conditions for a diverse range of forage species, and in these conditions cattle can graze continuously leading to pasture degradation. It is therefore essential to understand the spatial and temporal dynamics of forage production and consumption.
In this study we assessed and monitored vegetation, from long-term permanent plots located at the edge of one of the pond habitats intensively grazed by cattle, in order to evaluate degradation and quantify indicators of resilience (Briske et al. 2006)
Mobility, functionality and functional mobility: A review and application for canine veterinary patients
Mobility is an essential aspect of a dogâs daily life. It is defined as the ability to move freely and easily and deviations from an animalsâ normal mobility capabilities are often an indicator of disease, injury or pain. When a dogâs mobility is compromised, often functionality (ability to perform activities of daily living; ADL), is also impeded, which can diminish an animalâs quality of life. Given this, it is necessary to understand the extent to which conditions impact a dogâs physiological ability to freely move around their environment to carry out ADL, a concept termed functional mobility. In contrast to human medicine, validated measures of canine functional mobility are currently limited. The aim of this review is to summarise the extent to which canine mobility and functionality are associated with various diseases and how mobility and functional mobility are currently assessed within veterinary medicine. Future work should focus on developing a standardised method of assessing functional mobility in dogs, which can contextualise how a wide range of conditions impact a dogâs daily life. However, for a true functional mobility assessment to be developed, a greater understanding of what activities dogs do on a daily basis and movements underpinning these activities must first be established
Mobility, functionality and functional mobility: A review and application for canine veterinary patients
Mobility is an essential aspect of a dogâs daily life. It is defined as the ability to move freely and easily and deviations from an animalsâ normal mobility capabilities are often an indicator of disease, injury or pain. When a dogâs mobility is compromised, often functionality (ability to perform activities of daily living; ADL), is also impeded, which can diminish an animalâs quality of life. Given this, it is necessary to understand the extent to which conditions impact a dogâs physiological ability to freely move around their environment to carry out ADL, a concept termed functional mobility. In contrast to human medicine, validated measures of canine functional mobility are currently limited. The aim of this review is to summarise the extent to which canine mobility and functionality are associated with various diseases and how mobility and functional mobility are currently assessed within veterinary medicine. Future work should focus on developing a standardised method of assessing functional mobility in dogs, which can contextualise how a wide range of conditions impact a dogâs daily life. However, for a true functional mobility assessment to be developed, a greater understanding of what activities dogs do on a daily basis and movements underpinning these activities must first be established
Perspectives of Middle School Students on their Engagement and Relevance in Science
The purpose of this study is to explore urban middle school students\u27 thoughts and attitudes about engagement, belonging, use of their funds of knowledge (FoK), and discourse in their science classrooms. Historically, students from this population often feel disengaged and alienated from science, which is why it is important to study their point of view; and, there is currently a dearth of literature that does so (Emdin et al., 2021; Fredricks et al., 2018). The engagement model used includes behavioral, cognitive, affective and social dimensions (Wang et al., 2016). The data was collected in a study that involves collaboration between teachers and researchers, including the development of the science lessons that were taught during data collection. The data included 135 students across seven mid-Atlantic, urban middle school science classrooms in the United States. Students were administered surveys after their lessons, and later participated in focus group interviews collected in a previous study. Descriptive statistics and profile analysis were conducted on our quantitative data, resulting in 3 main profiles of students being identified. The profiles included (1) Above average engagement, FoK and discourse, (2) Below average engagement and FoK with high discourse, and (3) Average engagement and FoK with high discourse. Furthermore, qualitative themes were identified, such as students preferring group work and âhands-onâ lessons. Implications for practice and plans for future distribution are discussed.https://scholarscompass.vcu.edu/uresposters/1437/thumbnail.jp
- âŠ