3,180 research outputs found
Recreating mineralogical petrographic heterogeneity within microfluidic chips : assembly, examples, and applications
This material includes work supported by Royal Society Research Grant RG140009. BA was supported by a Society of Petrophysics and Well Log Analysts (SPWLA) grant and an Aberdeen Formation Evaluation Society (AFES) bursary. MC was supported by a University of Aberdeen College of Physical Sciences PhD studentship. The authors thank Munasuonyu Walter for SEM images of crushed marbleā , MSc students Oluwatoyole A. Adepoju and Vasiliki Koutsogianni for their contribution to the experiments, and undergraduate student Duncan Mackenzie for helpful discussions. Open Access via RSC Gold 4 GoldPeer reviewedPublisher PD
Magnetic susceptibility mapping of Point Pelee National Park beaches.
In the preliminary studies, the western and the Eastern shores of Point Pelee National Park (PPNP) showed a distinct spatial variation in their sediment magnetic properties (magnetic susceptibility). In order to determine the degree of spatial variability of field magnetic susceptibility and potential causes, the magnetic susceptibility of the beach sands were mapped in transects perpendicular to the shoreline of Lake Erie with a Bartington susceptibility meter. The West beaches showed no significant variation in susceptibility measurements, the East beaches showed highly variable susceptibility values which tended to increase towards the vegetation line. The East beaches magnetic susceptibility varied from 68*10-6 to 9000*10-6 (SI units), the West beaches were in the low range of 14*10-6 to 243.5*10-6. Magnetic susceptibility values were analysed and displayed with ARCGIS. Mineral magnetic analysis (anhysteretic remanence and saturation isothermal remanence measurements as well as temperature dependence of susceptibility measurements) indicated that the primary magnetic mineral throughout the Point Pelee beaches is pseudo single domain to single domain magnetite. Some variation in composition is apparent. Similar compositions and grainsize were observed to the north east of PPNP, on the Rondeau Provincial Park beaches and Wheatley beaches, suggesting either the same source or a similar sediment source. The temporal variations in susceptibility distribution, as well as high surface magnetic susceptibility due to the presence of magnetite-rich lamina suggest that sediment sorting and other beach processes is likely to cause the high magnetite concentration on the East beaches.Dept. of Earth Sciences. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis2005 .I33. Source: Masters Abstracts International, Volume: 44-03, page: 1312. Thesis (M.Sc.)--University of Windsor (Canada), 2005
Sustainable polycarbonate adhesives for dry and aqueous conditions with thermoresponsive properties
Pressure sensitive adhesives are ubiquitous in commodity products such as tapes, bandages, labels, packaging, and insulation. With single use plastics comprising almost half of yearly plastic production, it is essential that the design, synthesis, and decomposition products of future materials, including polymer adhesives, are within the context of a healthy ecosystem along with comparable or superior performance to conventional materials. Here we show a series of sustainable polymeric adhesives, with an eco-design, that perform in both dry and wet environments. The terpolymerization of propylene oxide, glycidyl butyrate, and CO2, catalyzed by a cobalt salen complex bearing a quaternary ammonium salt, yields the poly(propylene-co-glycidyl butyrate carbonate)s (PPGBC)s. ThisĀ polymeric adhesive system, composed of environmentally benign building blocks, implements carbon dioxide sequestration techniques, poses minimal environmental hazards, exhibits varied peel strengths from scotch tape to hot-melt wood-glue, and adheres to metal, glass, wood, and TeflonĀ® surfaces.Published versio
Rab14 regulates the maturation of macrophage phagosomes containing the fungal pathogen Candida albicans and the outcome of the host-pathogen interaction
Date of Acceptance: 02/02/2015 Copyright Ā© 2015, American Society for Microbiology. All Rights Reserved.Peer reviewedPublisher PD
Assessment of background radiation levels in selected diagnostic radiology department across Ondo State, Nigeria
The indoor and outdoor ionizing radiation exposure levels were measured in some randomly selected radiological laboratories of some hospitals across Ondo State, Nigeria using a Kindenoo PG - 15 Geiger Muller detector. Measurements were taken in each of the radiological laboratories of the hospitals in two phases: first, when the x-ray machines were energized and second, when the x-ray machines were not energized. The mean indoor and outdoor annual effective doses varied from 20.53Ā±1.07 to 39.12Ā±0.09 and 0.63Ā±0.32 to 1.17Ā±0.45 mSv/y respectively for the first phase in the radiological laboratories and from 1.68Ā±0.04 to 2.26Ā±0.07 and 0.28Ā±0.02 to 0.42Ā±0.02 mSv/y respectively for the second phase. Using statistical tools, a post-hoc test was carried out to test for the statistical significant difference between the indoor and outdoor annual effective dose in the study area. The test showed a significant difference between the indoor and outdoor annual effective dose at the radiological laboratories when the x-ray machine was energized and when the x-ray machine was not energized.Keywords: Indoor radiation exposure, Outdoor radiation exposure, X-ray, Annual effective dos
Restraining and unleashing chromatin remodelers - structural information guides chromatin plasticity.
Chromatin remodeling enzymes are large molecular machines that guard the genome by reorganizing chromatin structure. They can reposition, space and evict nucleosomes and thus control gene expression, DNA replication and repair. Recent cryo-electron microscopy (cryo-EM) analyses have captured snapshots of various chromatin remodelers as they interact with nucleosomes. In this review, we summarize and discuss the advances made in our understanding of the regulation of chromatin remodelers, the mode of DNA translocation, as well as the influence of associated protein domains and remodeler subunits on the specific functions of chromatin remodeling complexes. The emerging structural information will help our understanding of disease mechanisms and guide our knowledge toward innovative therapeutic interventions. Copyright Ā© 2020 Elsevier Ltd. All rights reserved
Accurate Judgment by Dementia Patients of Neutral Faces with Respect to Trustworthiness and Valence
The present study investigates whether dementia patients can make accurate social and affective judgments of face stimuli. We used verbal material as a control condition to see whether dementia patients are capable of using the rating scales the same way as controls. We compared the trustworthiness, valence, and arousal ratings of dementia patients with those from a healthy control group. Participants rated pictures of young and old, female and male neutral faces and two fictitious biographies. The results indicate that dementia patients make accurate judgments of unfamiliar faces with respect to trustworthiness and valence. Results concerning arousal ratings suggest that the corresponding scale might be difficult to use for dementia patients and possibly for older participants as well
Crystallography, magnetic susceptibility, heat capacity, and electrical resistivity of heavy fermion LiVO single crystals grown using a self-flux technique
Magnetically pure spinel compound is a rare -electron
heavy fermion. Measurements on single crystals are needed to clarify the
mechanism for the heavy fermion behavior in the pure material. In addition, it
is known that small concentrations ( mol%) of magnetic defects in the
structure strongly affect the properties, and measurements on single crystals
containing magnetic defects would help to understand the latter behaviors.
Herein, we report flux growth of and preliminary measurements
to help resolve these questions. The magnetic susceptibility of some as-grown
crystals show a Curie-like upturn at low temperatures, showing the presence of
magnetic defects within the spinel structure. The magnetic defects could be
removed in some of the crystals by annealing them at 700 C\@. A very
high specific heat coefficient = 450 mJ/(mol K\@) was obtained
at a temperature of 1.8 K for a crystal containing a magnetic defect
concentration = 0.5 mol%. A crystal with = 0.01 mol% showed a residual resistivity ratio of 50.Comment: 6 pages, 7 figures, Title modifie
Depth encoded input polarisation independent swept source cross-polarised optical coherence tomography probe
Within the last decades, several studies have been published that prove the benefit of polarisation sensitive optical coherence (psOCT) tomography for the field of biomedical diagnostics. However, polarisation sensitive imaging typically requires careful control of the polarisation state of the input illumination, which leads to bulky and delicate systems. While psOCT provides quantitative information, it is mostly sufficient to analyse the images qualitatively in the field of biomedical diagnostics. Therefore, a reduced form of this technique, cross-polarised optical coherence tomography (cpOCT), moves into the focus of interest that serves to visualise the birefringence properties of a sample. Despite the low requirements for the illumination's polarisation, most of the proposed systems still include complex illumination control mechanisms. Here, we propose a common path probe based endoscopic system with an lateral resolution of 30 Āµm and a sensitivity of 103 dB comprising a commercially available swept-source OCT system and a free-space module which does not require any polarisation controlling elements. A Faraday mirror substitutes the complex polarisation control apparatus. We demonstrate the independence of the approach from the polarisation state of the light source by monitoring the illumination power in the orthogonal channels while varying the source polarisation. Furthermore, we validate the ability of the system to reveal the birefringence properties of different samples, starting from a quarter-wave plate, since its properties are fully characterised. Additionally, we present imaging results from several tissues to demonstrate its feasibility for the field of biomedical diagnostics
Determinants of Loan Repayment Behaviour of Smallholder Cooperative Farmers in Yewa North Local Government Area of Ogun State, Nigeria: an Application of Tobit Model
The loan repayment performances of smallholder farmers were examined along with their determinants using data from selected cooperative members in Yewa area of Ogun State, Nigeria. A multistage random sampling technique guided the selection of 110 respondents on whom data were collected using structured questionnaire. Data were analyzed using descriptive statistics, correlation, and multivariate regression analytical techniques. Results revealed that the average age of respondents was 44.7 years with 36.4% falling into the 20-40 years active working population. Loan distribution showed that 67.3% of respondents received cooperative credit while the remainder received loan from other sources. Only 74.0% of all loans was fully repaid at due dates. Respondentsā average credit use experience was 9 years. A negative association was found between age and repayment performance, suggesting that younger farmers were better performers. From regression results, repayment performances were positively influenced by non-farm income (p<0.05) but negatively affected by loan size (p<0.01). Rates of response were inelastic for all variables: a 100% increase in loan size caused a 27.7% decrease while corresponding increase in non-farm income resulted to a 14.5% increase in repayment performance. Decomposed elasticities revealed that a small change in each variable resulted to a relatively higher change in the elasticity of repayment intensity than it had in elasticity of probability to repay by borrowers that have started repaying. The synergy between repayment performance and non-farm income underscored the strength of livelihood strategies and diversification in boosting economic activities of rural farmers. Loan packages that recognize this synergy and educate borrowers on befitting complementary livelihood options would likely achieve less rates of default from beneficiaries. Keywords: Farm credit, repayment performance, smallholder, cooperative farmers, Nigeria
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