399 research outputs found
Effect of dietary lipid and astaxanthin level on pigmentation of arctic charr (Salvelinus alpinus)
A 3 x 3 factorial design was used to study the effects of dietary lipid and astaxanthin levels on the pigmentation of Arctic charr (Salvelinus alpinus). Different groups of charr with mean initial weight of 70.16 ± 2.18 g were fed with diets containing 10, 18 or 26 % dietary lipid together with 40, 60 or 80 ppm synthetic astaxanthin for 24 weeks. The proximate composition of flesh, total carotenoid concentration in flesh and belly skin, and the Hunter colour values of filets, homogenized flesh and belly skin were determined at 4-week intervals. The apparent digestibility coefficient of carotenoid and specific growth rate (SGR) of the experimental fish at different dietary lipid and carotenoid levels were also investigated. Results indicated that: -- (1). The moisture content of flesh was inversely related to the level of dietary lipid, while there was a significant direct relationship between the content of flesh and dietary lipid. The protein and mineral content of flesh were not significantly influenced by the level of dietary lipid. -- (2). The total carotenoid concentration in flesh and belly skin of charr increased with time. The concentration of carotenoids in the flesh generally reached or exceeded 4 mg/kg wet tissue on week-16, 20 and 24 for the fish receiving 26, 18 and 10 % dietary lipid, respectively. This amount is considered as being sufficient for providing a satisfactory colour impression. The carotenoid concentration in the flesh and belly skin of fish was directly correlated with both dietary lipid and carotenoid levels. There was a significant interaction between dietary lipid and carotenoid levels on the total carotenoid concentration in flesh and belly skin of charr. A high correlation also existed between the carotenoid concentration and total lipid content in flesh. -- (3). The intensity of redness (Hunter a) and yellowness (Hunter b) of filet, homogenized flesh, and belly skin for all treatments increased with time on pigmented diets while their lightness (Hunter L) decreased. The Hunter L values of filet, homogenized flesh, and belly skin were inversely correlated with their carotenoid contents, whereas their Hunter a and b values correlated directly with the total carotenoid concentration. No significant relationship existed between any of the Hunter colour values and the lipid content in the flesh of charr. -- (4). The retention of carotenoids in charr flesh varied significantly among treatments, ranged from 4.13 to 10.66 %. The total amount of carotenoids retained in flesh was directly related to the content of dietary lipid, but inversely related to dietary carotenoid levels. There was a significant interaction of dietary lipid and carotenoid levels on the retention of carotenoids in flesh. -- (5). The apparent digestibility coefficient of carotenoids, ranging from 47.99 to 73.62 %, correlated directly with the content of dietary lipid, but inversely with dietary carotenoid levels. There was a high correlation between the amount of carotenoids retained in flesh and their digestibility. No interaction of dietary lipid and carotenoid on the carotenoid digestibility was observed. -- (6). The dietary lipid and carotenoid levels used in this study did not result in any abnormal growth of fish. The specific growth rate (SGR) of the fish fed 18 and 26% dietary lipid were significantly higher than that of the groups receiving 10% dietary lipid. In addition, at the same level of dietary lipid (18 %), the weight gains of fish on dietary carotenoids were faster than that of fish receiving no dietary carotenoids. However, these differences were not statistically significant. -- In conclusion, the results of the present study demonstrated that an increase in both lipid and carotenoid levels in charr diet enhances deposition of carotenoids in the fish flesh and skin. There was a significant interaction of dietary lipid and carotenoids on the pigmentation of Arctic charr. Thus, an increase in dietary lipid within a certain range may improve the pigmentation efficacy of charr
Algorithm Selection for Image Quality Assessment
Subjective perceptual image quality can be assessed in lab studies by human
observers. Objective image quality assessment (IQA) refers to algorithms for
estimation of the mean subjective quality ratings. Many such methods have been
proposed, both for blind IQA in which no original reference image is available
as well as for the full-reference case. We compared 8 state-of-the-art
algorithms for blind IQA and showed that an oracle, able to predict the best
performing method for any given input image, yields a hybrid method that could
outperform even the best single existing method by a large margin. In this
contribution we address the research question whether established methods to
learn such an oracle can improve blind IQA. We applied AutoFolio, a
state-of-the-art system that trains an algorithm selector to choose a
well-performing algorithm for a given instance. We also trained deep neural
networks to predict the best method. Our results did not give a positive
answer, algorithm selection did not yield a significant improvement over the
single best method. Looking into the results in depth, we observed that the
noise in images may have played a role in why our trained classifiers could not
predict the oracle. This motivates the consideration of noisiness in IQA
methods, a property that has so far not been observed and that opens up several
interesting new research questions and applications.Comment: Presented at the Seventh Workshop on COnfiguration and SElection of
ALgorithms (COSEAL), Potsdam, Germany, August 26--27, 201
Adrenomedullin delivery in microsphere-scaffold composite for remodeling of the alveolar bone following tooth extraction: an experimental study in the rat
BACKGROUND: Alveolar ridge resorption, as a significant problem in implant and restorative dentistry, has long been considered as an inevitable outcome following tooth extraction. Recently, adrenomedullin (ADM) is reported to be able to stimulate the proliferation and migration of various cells including osteoblasts. The purpose of this study was to investigate the influence of local ADM application in the tooth extraction socket in vivo. METHODS: Chitosan micropheres were developed by an emulsion-ionic cross-linking method for ADM delivery. Poly (L -lactic-co-glycolic) acid (PLGA) and nano-hydroxyapatite (nHA) were used to prepare scaffolds to contain the micrspheres with ADM. In vivo experiment was evaluated by transplanting the composite into the rat socket right after the incisor extraction. After 4, 8, 12 weeks implantation, radiographic and histological tests were carried out to evaluate the effect of released ADM on the alveolar bone. RESULTS: The microspheres had a spherical structure and a relative rough and uniform surface, and the particle size was under a normal distribution, with the average diameter of 38.59 μm. The scaffolds had open and interconnected pores. In addition, the high porosity of the composite was 88.93%. Radiographic and histological examination revealed that the PLGA/nHA/CMs/ADM composite could accelerate the alveolar bone remodeling and reduce the residual ridge resorption compared with the PLGA/nHA/CMs scaffold. CONCLUSIONS: The results of this study suggest that local application of ADM has the potential to preserve the residual alveolar ridge and accelerate the alveolar bone remodeling
ATTITUDE CONTROL OF AIR SPRING MOUNTING SYSTEM BASED ON FUZZY CONTROL
ABSTRACT Air spring is a kind of mount with excellent vibration isolation effect and it uses air as its elastic component. But its height is subject to constant change due to air leak or environment temperature and this restricts its engineering application. So some studies on attitude control are carried out, focusing on statically indeterminate and multivariable coupling air spring mounting systems in this paper. The Statically indeterminate problem is transformed through adding the constraint of loading evenness among air springs. After analyzing the model of this controlled object, a new control strategy based on coupling characteristic recognition is presented and combined with fuzzy logic control to realize attitude control of the multivariable coupling system. Finally, a test is conducted to show that the control strategy is feasible and the control system has good static and dynamic properties
Recovering Sign Bits of DCT Coefficients in Digital Images as an Optimization Problem
Recovering unknown, missing, damaged, distorted or lost information in DCT
coefficients is a common task in multiple applications of digital image
processing, including image compression, selective image encryption, and image
communications. This paper investigates recovery of a special type of
information in DCT coefficients of digital images: sign bits. This problem can
be modelled as a mixed integer linear programming (MILP) problem, which is
NP-hard in general. To efficiently solve the problem, we propose two
approximation methods: 1) a relaxation-based method that convert the MILP
problem to a linear programming (LP) problem; 2) a divide-and-conquer method
which splits the target image into sufficiently small regions, each of which
can be more efficiently solved as an MILP problem, and then conducts a global
optimization phase as a smaller MILP problem or an LP problem to maximize
smoothness across different regions. To the best of our knowledge, we are the
first who considered how to use global optimization to recover sign bits of DCT
coefficients. We considered how the proposed methods can be applied to
JPEG-encoded images and conducted extensive experiments to validate the
performances of our proposed methods. The experimental results showed that the
proposed methods worked well, especially when the number of unknown sign bits
per DCT block is not too large. Compared with other existing methods, which are
all based on simple error-concealment strategies, our proposed methods
outperformed them with a substantial margin, both according to objective
quality metrics (PSNR and SSIM) and also our subjective evaluation. Our work
has a number of profound implications, e.g., more sign bits can be discarded to
develop more efficient image compression methods, and image encryption methods
based on sign bit encryption can be less secure than we previously understood.Comment: 13 pages, 8 figure
Nucleotide-level prediction of CircRNA-protein binding based on fully convolutional neural network
Introduction: CircRNA-protein binding plays a critical role in complex biological activity and disease. Various deep learning-based algorithms have been proposed to identify CircRNA-protein binding sites. These methods predict whether the CircRNA sequence includes protein binding sites from the sequence level, and primarily concentrate on analysing the sequence specificity of CircRNA-protein binding. For model performance, these methods are unsatisfactory in accurately predicting motif sites that have special functions in gene expression.Methods: In this study, based on the deep learning models that implement pixel-level binary classification prediction in computer vision, we viewed the CircRNA-protein binding sites prediction as a nucleotide-level binary classification task, and use a fully convolutional neural networks to identify CircRNA-protein binding motif sites (CPBFCN).Results: CPBFCN provides a new path to predict CircRNA motifs. Based on the MEME tool, the existing CircRNA-related and protein-related database, we analysed the motif functions discovered by CPBFCN. We also investigated the correlation between CircRNA sponge and motif distribution. Furthermore, by comparing the motif distribution with different input sequence lengths, we found that some motifs in the flanking sequences of CircRNA-protein binding region may contribute to CircRNA-protein binding.Conclusion: This study contributes to identify circRNA-protein binding and provides help in understanding the role of circRNA-protein binding in gene expression regulation
Direct observation of domain wall motion and novel dielectric loss in 0.23Pb(In1/2Nb1/2)O3–0.42Pb(Mg1/3Nb2/3)O3–0.35PbTiO3 crystals
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