2,709 research outputs found
CONTROL AND PASSIVE TREATMENT OF RUNOFF FROM HORSE MUCK STORAGE STRUCTURES USING RAIN GARDENS
Runoff from livestock operations may contain a variety of pathogens and high levels of nutrients and other harmful contaminants, and is of particular concern in central Kentucky as watersheds are threatened by waste generated from a high concentration of equine activity. Rain gardens are a type of stormwater management tool used to capture and passively treat runoff. This project aimed to incorporate rain gardens into the horse muck storage structures at a thoroughbred facility in the Canr Run watershed in Lexington, Kentucky. Water quality data from soil water within two rain garden muck pads and two control pads, and grab samples from the stream were compared. No significant differences were observed, but trends revealed higher levels of nitrate and phosphate in rain gardens compared to controls, while total organic carbon and E. coli levels were lower in the rain gardens, suggesting that the rain gardens are trapping nutrients while reducing organic matter and killing bacteria. E. coli populations were lower in stream sample locations near rain garden muck pads compared to further downstream near controls. Management recommendations include further improvement of muck storage structures, replacing old muck pads, and changing management and housekeeping habits and attitudes towards environmental responsibility
Discovery of an OVI Emitting Nebula around the Hot White Dwarf KPD 0005+5106
A survey of diffuse interstellar sight lines observed with the Far
Ultraviolet Spectroscopic Explorer has led to the serendipitous discovery of a
high-ionization nebula around the hot white dwarf KPD 0005+5106. The nebula has
an OVI 1032A surface brightness of up to 25,000 photons/s/cm^2/sr, making it
the brightest region of extended OVI emission in our survey. Photoionization
models using the incident white dwarf continuum successfully reproduce the
observed OVI intensity. The OVI emission arises in the highly ionized inner
region of a planetary nebula around KPD 0005+5106. This newly discovered nebula
may be one member of a class of high-ionization planetary nebulae that are
difficult to detect in the optical, but which can be easily identified in the
ultraviolet.Comment: accepted for publication in ApJL, 11 pages including 2 figure
Cover Crops Cover a Lot of Possibilities
Cover crops have been used for centuries. However, today\u27s modern farmers have grown up in a generation or two which has replaced the use of cover crops with fertilizers and herbicides
Effect of local chemistry and structure on thermal transport in doped GaAs
Using a first-principles approach, we analyze the impact of \textit{DX}
centers formed by S, Se, and Te dopant atoms on the thermal conductivity of
GaAs. Our results are in good agreement with experiments and unveil the physics
behind the drastically different effect of each kind of defect. We establish a
causal chain linking the electronic structure of the dopants to the thermal
conductivity of the bulk solid, a macroscopic transport coefficient.
Specifically, the presence of lone pairs leads to the formation of structurally
asymmetric \textit{DX} centers that cause resonant scattering of incident
phonons. The effect of such resonances is magnified when they affect the part
of the spectrum most relevant for thermal transport. We show that these
resonances are associated with localized vibrational modes in the perturbed
phonon spectrum. Finally, we illustrate the connection between flat adjacent
minima in the energy landscape and resonant phonon scattering through detailed
analyses of the energy landscape of the defective structures.Comment: 7 pages, 7 figure
Advance directives and the impact of timing. A qualitative study with Swiss general practitioners.
PRINCIPLES: Advance directives are seen as an important tool for documenting the wishes of patients who are no longer competent to make decisions in regards to their medical care. Due to their nature, approaching the subject of advance directives with a patient can be difficult for both the medical care provider and the patient. This paper focuses on general practitioners' perspectives regarding the timing at which this discussion should take place, as well as the advantages and disadvantages of the different moments.
METHODS: In 2013, 23 semi-structured face-to-face interviews were performed with Swiss general practitioners. Interviews were analysed using qualitative content analysis.
RESULTS: In our sample, 23 general practitioners provided different options that they felt were appropriate moments: either (a) when the patient is still healthy, (b) when illness becomes predominant, or (c) when a patient has been transferred to a long-term care facility. Furthermore, general practitioners reported uncertainty and discomfort regarding initiating the discussion.
CONCLUSION: The distinct approaches, perspectives and rationales show that there is no well-defined or "right" moment. However, participants often associated advance directives with death. This link caused discomfort and uncertainty, which led to hesitation and delay on the part of general practitioners. Therefore we recommend further training on how to professionally initiate a conversation about advance directives. Furthermore, based on our results and experience, we recommend an early approach with healthy patients paired with later regular updates as it seems to be the most effective way to inform patients about their end-of-life care options
Investigation of the μ- and κ-opioid receptor activation by eight new synthetic opioids using the [S]-GTPγS assay: U-47700, isopropyl U-47700, U-49900, U-47931E, N-methyl U-47931E, U-51754, U-48520, and U-48800
In 2009, new synthetic opioids appeared on the new psychoactive substances market. This class of new psychoactive substances generally poses a health risk due to the high affinity and potency of most of these compounds for the opioid receptors. It is known that overdoses can lead to respiratory depression and result in death. However, for many new synthetic opioids, data on toxicological and toxicokinetic properties are scarce. In the present study, eight U-opioids were investigated for their structure activity relationships at the μ- and κ-opioid receptors using a [S]-GTPγS assay. The potencies of the investigated U-opioids were lower than those of the reference compounds (μ-opioid receptor: hydromorphone, fentanyl; κ-opioid receptor: U-69593, U-50488). At the μ-opioid receptor, U-47700 showed the highest potency with an EC value of 111 nM, and at the κ-opioid receptor, U-51754 was found to be the most potent compound with an EC value of 120 nM. The following structural features were advantageous for activating the μ-opioid receptor: two chlorine substituents in 3,4-position at the aromatic ring, the absence of the methylene group between the amide group and the aromatic ring, a methyl group at the amide nitrogen, and/or a dimethylamine residue at the amine nitrogen of the cyclohexane ring. Further, the following structural features were beneficial for κ-opioid receptor activation: a methylene group between the amide group and the aromatic ring, a pyrrolidine residue at the amine nitrogen of the cyclohexane ring, a methyl group at the amide nitrogen, and/or a chlorine substitution at the 3,4-position of the aromatic ring
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