773 research outputs found
Surface moisture increases microcracking and water vapour permeance of apple fruit skin
Surface moisture induces microcracking in the cuticle of fruit skins. Our objective was to study the effects of surface moisture on cuticular microcracking, the permeance to water vapour and russeting in developing ‘Pinova’ apple fruit. Surface moisture was applied by fixing to the fruit a plastic tube containing deionized water. Microcracking was quantified by fluorescence microscopy and image analysis following infiltration with acridine orange. Water vapour permeance was determined gravimetrically using skin segments (ES) mounted in diffusion cells. Cumulative water loss through the ES increased linearly with time. Throughout development, surface moisture significantly increased skin permeance. The effect was largest during early development and decreased towards maturity. Recovery time courses revealed that following moisture treatment of young fruit for 12 days, skin permeance continued to increase until about 14 days after terminating the moisture treatment. Thereafter, skin permeance decreased over the next 28 days, then approaching the control level. This behaviour indicates gradual healing of the impaired cuticular barrier. Nevertheless, permeance still remained significantly higher compared with the untreated control. Similar patterns of permeance change were observed following moisture treatments at later stages of development. The early moisture treatment beginning at 23 DAFB resulted in russeting of the exposed surfaces. There was no russet in control fruit without a tube or in control fruit with a tube mounted for 12 days without water. The data demonstrate that surface moisture increases microcracking and water vapour permeance. This may lead to the formation of a periderm and, hence, a russeted fruit surface
Effect of cropping sequences on soil biological activity in semiarid region of western Canada
Non-Peer ReviewedSoil productivity and environmental sustainability hinge on the physical, chemical and biological properties of the soil. Soil dehydrogenases (DHs) are one of the major classes of intracellular oxidoreductase enzymes involved in energy metabolism of living cells. The soil DHs activity is used as an indicator of overall soil microbial activity. This study employed the soil DHs assay to examine the effect of different cropping sequences including wheat, mustard and pulse crops in 4-year rotation on the soil biological activity. The DHs assay used in this study was originally developed by Le Casida et al. (1964). In this method, triphenyltetrazolium chloride (TTC) is used as an indicator dye that helps to observe electron transport system activity. The DHs involved in electron transport system reduce the colourless soluble TTC (substrate) and convert it into an insoluble red colour product, known as triphenylformazan (TPF). TPF can be quantified by spectrophotometry at the visible wavelength of 485 nm. Higher the intensity of the red colour in the soil extract solution, higher is the concentration of TPF and hence the higher DHs activity. In this study, the results of DHs assay of the final year (2014) of different 4-year crop rotations are presented. The study clearly showed that frequent inclusion of pulse crops especially chickpea in the cropping systems is conducive to the soil biological activity
Fast multiple landmark localisation using a patch-based iterative network
We propose a new Patch-based Iterative Network (PIN) for fast and accurate landmark localisation in 3D medical volumes. PIN utilises a Convolutional Neural Network (CNN) to learn the spatial relationship between an image patch and anatomical landmark positions. During inference, patches are repeatedly passed to the CNN until the estimated landmark position converges to the true landmark location. PIN is computationally efficient since the inference stage only selectively samples a small number of patches in an iterative fashion rather than a dense sampling at every location in the volume. Our approach adopts a multi-task learning framework that combines regression and classification to improve localisation accuracy. We extend PIN to localise multiple landmarks by using principal component analysis, which models the global anatomical relationships between landmarks. We have evaluated PIN using 72 3D ultrasound images from fetal screening examinations. PIN achieves quantitatively an average landmark localisation error of 5.59mm and a runtime of 0.44s to predict 10 landmarks per volume. Qualitatively, anatomical 2D standard scan planes derived from the predicted landmark locations are visually similar to the clinical ground truth
Standard plane detection in 3D fetal ultrasound using an iterative transformation network
Standard scan plane detection in fetal brain ultrasound (US) forms a crucial step in the assessment of fetal development. In clinical settings, this is done by manually manoeuvring a 2D probe to the desired scan plane. With the advent of 3D US, the entire fetal brain volume containing these standard planes can be easily acquired. However, manual standard plane identification in 3D volume is labour-intensive and requires expert knowledge of fetal anatomy. We propose a new Iterative Transformation Network (ITN) for the automatic detection of standard planes in 3D volumes. ITN uses a convolutional neural network to learn the relationship between a 2D plane image and the transformation parameters required to move that plane towards the location/orientation of the standard plane in the 3D volume. During inference, the current plane image is passed iteratively to the network until it converges to the standard plane location. We explore the effect of using different transformation representations as regression outputs of ITN. Under a multi-task learning framework, we introduce additional classification probability outputs to the network to act as confidence measures for the regressed transformation parameters in order to further improve the localisation accuracy. When evaluated on 72 US volumes of fetal brain, our method achieves an error of 3.83mm/12.7 degrees and 3.80mm/12.6 degrees for the transventricular and transcerebellar planes respectively and takes 0.46s per plane
Poor Thermal Care Practices among Home Births in Nepal: Further Analysis of Nepal Demographic and Health Survey 2011
Introduction - Hypothermia is a major factor associated with neonatal mortality in low and middle income countries. Thermal care protection of newborn through a series of measures taken at birth and during the initial days of life is recommended to reduce the hypothermia and associated neonatal mortality. This study aimed to identify the prevalence of and the factors associated with receiving ‘optimum thermal care’ among home born newborns of Nepal. Methods - Data from the Nepal Demographic and Health Surveys (NDHS) 2011 were used for this study. Women who reported a home birth for their most recent childbirth was included in the study. Factors associated with optimum thermal care were examined using Chi-square test followed by logistic regression. Results - A total of 2464 newborns were included in the study. A total of 57.6 % were dried before the placenta was delivered; 60.3% were wrapped; 24.5% had not bathing during the first 24 hours, and 63.9% were breastfed within one hour of birth. Overall, only 248 (10.7%; 95% CI (8.8 %, 12.9%)) newborns received optimum thermal care. Newborns whose mothers had achieved higher education (OR 2.810; 95% CI (1.132, 6.976)), attended four or more antenatal care visits (OR 2.563; 95% CI (1.309, 5.017)), and those whose birth were attended by skilled attendants (OR 2.178; 95% CI (1.428, 3.323)) were likely to receive optimum thermal care. Conclusion - The current study showed that only one in ten newborns in Nepal received optimum thermal care. Future newborn survival programs should focus on those mothers who are uneducated; who do not attend the recommended four or more attend antenatal care visits; and those who deliver without the assistance of skilled birth attendants to reduce the risk of neonatal hypothermia in Nepal
Entropy in the NUT-Kerr-Newman Black Holes Due to an Arbitrary Spin Field
Membrane method is used to compute the entropy of the NUT-Kerr-Newman black
holes. It is found that even though the Euler characteristic is greater than
two, the Bekenstein-Hawking area law is still satisfied. The formula relating the entropy and the Euler characteristic becomes inapplicable for
non-extreme four dimensional NUT-Kerr-Newman black holes
Biological impact of nanodiamond particles – label free, high-resolution methods for nanotoxicity assessment
Current methods for the assessment of nanoparticle safety that are based on 2D cell culture models and fluorescence-based assays show limited sensitivity and they lack biomimicry. Consequently, the health risks associated with the use of many nanoparticles have not yet been established. There is a need to develop in vitro models that mimic physiology more accurately and enable high throughput assessment. There is also a need to set up new assays that offer high sensitivity and are label-free. Here we developed ‘mini-liver’ models using scaffold-free bioprinting and used these models together with label-free nanoscale techniques for the assessment of toxicity of nanodiamond produced by laser-assisted technology. Results showed that NDs induced cytotoxicity in a concentration and exposure-time dependent manner. The loss of cell function was confirmed by increased cell stiffness, decreased cell membrane barrier integrity and reduced cells mobility. We further showed that NDs elevated the production of reactive oxygen species and reduced cell viability. Our approach that combined mini-liver models with label-free high-resolution techniques showed improved sensitivity in toxicity assessment. Notably, this approach allowed for label-free semi-high throughput measurements of nanoparticle-cell interactions, thus could be considered as a complementary approach to currently used methods
Entropy of a Kerr-de Sitter black hole due to arbitrary spin fields
The Newman-Penrose formalism is used to derive the Teukolsky master equations
controlling massless scalar, neutrino, electromagnetic, gravitino, and
gravitational field perturbations of the Kerr-de Sitter spacetime. Then the
quantum entropy of a non-extreme Kerr-de Sitter black hole due to arbitrary
spin fields is calculated by the improved thin-layer brick wall model. It is
shown that the subleading order contribution to the entropy is dependent on the
square of the spins of particles and that of the specific angular momentum of
black holes as well as the cosmological constant. The logarithmic correction of
the spins of particles to the entropy relies on the rotation of the black hole
and the effect of the cosmological constant.Comment: 28 pages, two figures, Revtex4.0. Final revised version to appear in
PR
On Holographic description of the Kerr-Newman-AdS-dS black holes
In this paper, we study the holographic description of the generic
four-dimensional non-extremal Kerr-Newman-AdS-dS black holes. We find that if
focusing on the near-horizon region, for the massless scalar scattering in the
low-frequency limit, there exists hidden conformal symmetry on the solution
space. Similar to the Kerr case, this suggests that the Kerr-Newman-AdS-dS
black hole is dual to a two-dimensional CFT with central charges
and temperatures
. The macroscopic Bekenstein-Hawking
entropy could be recovered from the microscopic counting in dual CFT via the
Cardy formula. Using the Minkowski prescription, we compute the real-time
correlators of the scalar, photon and graviton in near horizon geometry of near
extremal Kerr-AdS-dS black hole. In all these cases, the retarded Green's
function and the corresponding absorption cross section are in perfect match
with CFT prediction. We further discuss the low-frequency scattering of a
charged scalar by a Kerr-Newman-AdS-dS black hole and find the dual CFT
description.Comment: 22 pages; minor corrections, conlusion unchanged, references
added;published versio
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