1,676 research outputs found
Nanodiamond arrays on glass for quantification and fluorescence characterisation
Quantifying the variation in emission properties of fluorescent nanodiamonds
is important for developing their wide-ranging applicability. Directed
self-assembly techniques show promise for positioning nanodiamonds precisely
enabling such quantification. Here we show an approach for depositing
nanodiamonds in pre-determined arrays which are used to gather statistical
information about fluorescent lifetimes. The arrays were created via a layer of
photoresist patterned with grids of apertures using electron beam lithography
and then drop-cast with nanodiamonds. Electron microscopy revealed a 90%
average deposition yield across 3,376 populated array sites, with an average of
20 nanodiamonds per site. Confocal microscopy, optimised for nitrogen vacancy
fluorescence collection, revealed a broad distribution of fluorescent lifetimes
in agreement with literature. This method for statistically quantifying
fluorescent nanoparticles provides a step towards fabrication of hybrid
photonic devices for applications from quantum cryptography to sensing
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Control of contagious bovine pleuropneumonia: knowledge, attitudes, perceptions and practices in Narok district of Kenya
CBPP is an important transboundary disease in sub-Saharan Africa whose control is urgent. Participatory data collection involving 52 focus group discussions in 37 village clusters and key informant interviews, a cross-sectional study involving 232 households and a post-vaccination follow up involving 203 households was carried out in 2006–2007 in Narok South district of Kenya. This was to investigate knowledge, attitudes, perceptions and practices (KAPP) associated with control of CBPP as well as the adverse post-vaccination reactions in animals in order to advice the control policy. The community perceived trans-boundary CBPP threat to their cattle. They had traditional disease coping mechanisms and were conversant with CBPP prevention and control with 49.8% (95%CI: 42.8–56.7%) giving priority to CBPP control. However, 12.9% (95%CI: 9.0–18.1%) of pastoralists had no knowledge of any prevention method and 10.0% (95%CI: 6.5–14.7%) would not know what to do or would do nothing in the event of an outbreak. Although 43.5% (95%CI: 37.1–50.2%) of pastoralists were treating CBPP cases with antimicrobials, 62.5% (95%CI: 52.1–71.7%) of them doubted the effectiveness of the treatments. Pastoralists perceived vaccination to be the solution to CBPP but vaccination was irregular due to unavailability of the vaccine. Vaccination was mainly to control outbreaks rather than preventive and exhibited adverse post-vaccination reactions among 70.4% (95%CI: 63.6–76.5%) of herds and 3.8% (95%CI: 3.5–4.2%) of animals. Consequently, nearly 25.2% (95%CI: 18.5–33.2%) of pastoralists may resist subsequent vaccinations against CBPP. Pastoralists preferred CBPP vaccination at certain times of the year and that it is combined with other vaccinations. In conclusion, pastoralists were not fully aware of the preventive measures and interventions and post-vaccination reactions may discourage subsequent CBPP vaccinations. Consequently there is need for monitoring and management of post vaccination reactions and awareness creation on CBPP prevention and interventions and their merits and demerits. CBPP vaccine was largely unavailable to the pastoralists and the preference of the pastoralists was for vaccination at specified times and vaccine combinations which makes it necessary to avail the vaccine in conformity with the pastoralists preferences. In addition, planning vaccinations should involve pastoralists and neighbouring countries. As the results cannot be generalized, further studies on CBPP control methods and their effectiveness are recommended
Fluoroscopic imaging overestimates the screw tip to subchondral bone distance in a cadaveric model of slipped capital femoral epiphysis
PURPOSE: Intra-operative imaging plays a key role in screw placement for slipped capital femoral epiphysis (SCFE). Complications have been associated with inadequate screw position. The purpose of this study was to evaluate computed tomography (CT) (3D fluoroscopy) and standard fluoroscopy (C-arm) images as compared with direct anatomic measurement to determine final screw position in a cadaveric SCFE model.
METHODS: Osteotomy with pinning was performed at the physeal scar in ten cadaveric hips. A standardised approach-withdrawal technique was performed with C-arm images taken at 15 degrees increments. We also obtained a CT (3D fluoroscopy) scan of each hip. The screw tip-subchondral bone (STSB) distance was measured on digital imaging software and also with a digital calliper directly when the femoral head was cut in plane to expose the STSB distance anatomically. Statistical analysis included t-tests and Fisher\u27s exact test.
RESULTS: Moderate SCFE osteotomies were achieved with a mean Southwick angle (39.5 degrees +/- 7 degrees ). The 60 degrees fluoroscopic image was found to be the most representative image (41% of the time) compared with both anteroposterior (AP) and lateral images (8% and 21%). Both fluoroscopy (2.7 +/- 0.8 mm, p \u3c 0.001) and CT (1.6 +/- 0.7 mm, p = 0.03) overestimated the STSB distance compared with direct measurement (0.94 +/- 0.51 mm). Two-thirds (67%) of CT measurements were within 1 mm of the cadaveric measurement, while only 20% of C-arm measurements fulfilled this criterion (p = 0.04).
CONCLUSIONS: Both standard fluoroscopy and CT overestimated the STSB distance when compared with direct measurement in a cadaveric model of SCFE. Surgeons should be aware of the limitations of intra-operative imaging to determine the STSB distance. We suggest that using the known pitch of a screw (2.9 mm in a 7.3-mm cannulated screw) as an intra-operative tool to help guide screw placement
Police accountability and the Irish law of evidence
"Common law courts have differed on whether and to what extent an exclusionary rule should be used as a tool to impose standards on the police. The Irish courts have pursued an uncompromising approach in this area. Basing themselves on the imperative of upholding the constitutional rights of the accused, they have been willing to exclude relevant and cogent evidence on the basis that it was obtained by the police in breach of those rights. This article locates the Irish constitutional exclusionary rule in the broader context of the role of the law of evidence in police governance. Citing specific examples from the Irish legislation and case law, it shows how recent legislative interventions and some judicial hesitancy have fuelled inconsistent and contradictory trends. It concludes that there is now a pressing need for reflection on the respective roles of the legislature and the courts in this area." [author's abstract
Effects of D-amino acid oxidase inhibition on memory performance and long-term potentiation in vivo
N-methyl-d-aspartate receptor (NMDAR) activation can initiate changes in synaptic strength, evident as long-term potentiation (LTP), and is a key molecular correlate of memory formation. Inhibition of d-amino acid oxidase (DAAO) may increase NMDAR activity by regulating d-serine concentrations, but which neuronal and behavioral effects are influenced by DAAO inhibition remain elusive. In anesthetized rats, extracellular field excitatory postsynaptic potentials (fEPSPs) were recorded before and after a theta frequency burst stimulation (TBS) of the Schaffer collateral pathway of the CA1 region in the hippocampus. Memory performance was assessed after training with tests of contextual fear conditioning (FC, mice) and novel object recognition (NOR, rats). Oral administration of 3, 10, and 30 mg/kg 4H-furo[3,2-b]pyrrole-5-carboxylic acid (SUN) produced dose-related and steady increases of cerebellum d-serine in rats and mice, indicative of lasting inhibition of central DAAO. SUN administered 2 h prior to training improved contextual fear conditioning in mice and novel object recognition memory in rats when tested 24 h after training. In anesthetized rats, LTP was established proportional to the number of TBS trains. d-cycloserine (DCS) was used to identify a submaximal level of LTP (5× TBS) that responded to NMDA receptor activation; SUN administered at 10 mg/kg 3–4 h prior to testing similarly increased in vivo LTP levels compared to vehicle control animals. Interestingly, in vivo administration of DCS also increased brain d-serine concentrations. These results indicate that DAAO inhibition increased NMDAR-related synaptic plasticity during phases of post training memory consolidation to improve memory performance in hippocampal-dependent behavioral tests
Analysis of social, fiscal, and structural factors affecting integrated pest management programs in Missouri and implications for future programs to protect water quality
Integrated Pest Management (IPM) has experienced a resurgence of interest due in part to continuing reports of drinking water contamination by agricultural pesticides. In response to the decertification of certain pesticides used for soil insect control on corn, in the early 1970s federal programs established Cooperative Extension Service sponsored IPM programs in several midwestern States to promote insect scouting on corn and cotton. This report documents the various factors which facilitated the growth and decline of these programs in Missouri and the ongoing transformation of such services into the private sector and other agencies. The objective of this report is to provide policy prescriptions to enhance the future adoption of IPM in Missouri and other areas that will facilitate the protection of water resources. Research in Missouri regarding pesticide use practices and water quality issues indicates that there is a considerably higher incidence of IPM use in counties that historically had, or still currently have, Extension sponsored programs. Interviews were conducted with University personnel responsible for implementing these programs, county Extension agents responsible for overseeing the programs, private sector businesspeople who are currently offering IPM services, and farm opeators who previously used, and/or now participate in, IPM Extension programs or private services. Interviewees were asked what factors contributed to the success, failure, and/or transformation of the county programs. Results indicate that these factors include quality and turnover of the scouts, committment of the Extension agent, economic and climatological variables, institutional support, and packaging IPM programs with other programs such as irrigation.Project # G-2029-04 Agreement # 14-08-0001-G-2029-0
Preparation And Characterization Of Composite Hollow Fiber Reverse Osmosis Membranes By Plasma Polymerization. 1. Design Of Plasma Reactor And Operational Parameters
Composite hollow fiber reverse osmosis membranes were prepared by depositing a thin layer (10-50 nm) of plasma polymers on hollow fibers with porous walls (made of polysulfone). The coating was carried out in a semicontinuous manner with six strands of substrate fibers. Operational parameters which influence reverse osmosis characteristics of composite membranes were investigated. © 1984, American Chemical Society. All rights reserved
The effect of signal acquisition and processing choices on ApEn values: Towards a “gold standard” for distinguishing effort levels from isometric force records
Approximate Entropy (ApEn) is frequently used to identify changes in the complexity of isometric force records with ageing and disease. Different signal acquisition and processing parameters have been used, making comparison or confirmation of results difficult. This study determined the effect of sampling and parameter choices by examining changes in ApEn values across a range of submaximal isometric contractions of the First Dorsal Interosseus. Reducing the sample rate by decimation changed both the value and pattern of ApEn values dramatically. The pattern of ApEn values across the range of effort levels was not sensitive to the filter cut-off frequency, or the criterion used to extract the section of data for analysis. The complexity increased with increasing effort levels using a fixed ‘r’ value (which accounts for measurement noise) but decreased with increasing effort level when ‘r’ was set to 0.1 of the standard deviation of force. It is recommended isometric force records are sampled at frequencies >200 Hz, template length (‘m’) is set to 2, and 'r' set to measurement system noise or 0.1 SD depending on physiological process to be distinguished. It is demonstrated that changes in ApEn across effort levels are related to changes in force gradation strategy
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