Magnetic resonance (MR) images can be corrupted by artifacts and noise, potentially leading to misinterpretation of the images. In this paper, we propose a novel approach based on the discrete shape ...space of images (DSSI) to jointly reduce artifacts and noise in MR images. The proposed method restores MR images in multiple domains based on the distinct generation mechanisms of noise and artifacts. The images in multiple domains are analyzed in a non-Euclidean space. The DSSI is constructed as a Riemannian manifold to measure the intrinsic properties of images. Images are considered shapes from a geometric perspective, and the impact of similarity transformations (e.g., rotation, scaling, and translation) on image analysis is eliminated. The patch-based rank-ordered difference (PROD) detector is defined in k-space within the framework of DSSI to detect and remove sparse outliers that cause artifacts. In addition, a novel similarity function for images is defined using the DSSI and be used to design the improved filter. Finally, the convergence of the improved filter is theoretically analyzed, indicating that our method offers an effective estimator of the ideal image. The experimental results of various MR images demonstrate that the proposed approach outperforms classical and state-of-the-art methods for artifact correction and noise removal, both qualitatively and quantitatively.
•We propose a method for enhancing MR image quality by reducing artifacts and noise simultaneously. Motivated by the properties of these undesired components, our method combines the advantages of both k-space and image space to enhance images.•We construct the discrete shape space of images (DSSI) to measure the intrinsic image similarity in Riemannian manifold by treating images as shapes from a geometric view. Therefore, image similarity is independent of similarity transformations.•The patch-based rank-ordered difference (PROD) is defined under the framework of the DSSI to detect and remove MR artifacts in k-space. The PROD is defined by a signed distance between patches as artifacts usually appear as sparse outliers with prominent features.•We design an improved filter using the similarity function of images defined in the DSSI to reduce noise in the image space. This is an interesting advantage when compared with the similarity function used in the classical NLM, which is rather sensitive to rotation.•We theoretically investigate the convergence of our improved filter and find that using the geometric information of images to measure the similarity between images can ensure that the restored image is an effective estimator of the ideal image.
Human activities and city routines follow patterns. Transfer learning can help achieve scalable solutions toward the realization of smart cities accounting for similarities between regions, domains, ...and activities. In this study, we propose a transfer learning-based framework for smart buildings to test this hypothesis in energy-related problems. Our framework has two major components: the network creation and the transferable predictive model. In order to create the network that groups buildings sharing characteristics, we evaluated two strategies: a novel clustering algorithm for mixed data, k -prod, and clustering the image-based representation of time series. Then, a combination of long short term memory and convolutional neural network was trained on the centroids of the clusters for energy consumption prediction. The coefficient of variation of the root mean squared error (CVRMSE) of the predictions in such clusters vary between 3.85% and 58.85%. The obtained parameters were transferred to the rest of the buildings for predictive purposes, finding accurate results in buildings with little data. Our framework deals with insufficient training data since parameters from scenarios with more sensors can be received. It also carries out state-of-the-art performance on three datasets from different sources having in total 533 rooms/buildings and two energy efficiency domains: consumption prediction reducing the CVRMSE in a 21.6%, and air conditioning usage prediction moving from a 4.18% to a 0.28% CVRMSE. Our framework extracts more knowledge from available IoT deployments, so that smartness could be spread between environments at a fewer cost given that less individual effort will be needed.
Interspecific crosses can result in progeny with reduced vitality or fertility due to genetic incompatibilities between species, a phenomenon known as hybrid incompatibility (HI). HI is often caused ...by a bias against deleterious allele combinations, which results in transmission ratio distortion (TRD). Here, we determined the genome-wide distribution of HI between wild lettuce,
, and cultivated lettuce,
, in a set of backcross inbred lines (BILs) with single introgression segments from
introgressed into a
genetic background. Almost all BILs contained an introgression segment in a homozygous state except a few BILs, for which we were able to obtain only a single heterozygous introgression. Their inbred progenies displayed severe TRD with a bias toward the
allele and complete nontransmission of the homozygous
introgression,
, absolute HI. These HI might be caused by deleterious heterospecific allele combinations at two loci. We used an multilocus segregating interspecific F2 population to identify candidate conspecific loci that can nullify the HI in BILs. Segregation analysis of developed double-introgression progenies showed nullification of three HI and proved that these HI are explained by nuclear pairwise incompatibilities. One of these digenic HI showed 29% reduced seed set and its pattern of TRD pointed to a sex-independent gametophytic barrier. Namely, this HI was caused by complete nontransmission of one heterospecific allele combination at the haploid stage, surprisingly in both male and female gametophytes. Our study shows that two-locus incompatibility systems contribute to reproductive barriers among
species.
Key message
The nonhost resistance of wild lettuce to lettuce downy mildew seems explained by four components of a putative set of epistatic genes.
The commonplace observation that plants are immune ...to most potential pathogens is known as nonhost resistance (NHR). The genetic basis of NHR is poorly understood. Inheritance studies of NHR require crosses of nonhost species with a host, but these crosses are usually unsuccessful. The plant-pathosystem of lettuce and downy mildew,
Bremia lactucae
, provides a rare opportunity to study the inheritance of NHR, because the nonhost wild lettuce species
Lactuca saligna
is sufficiently cross-compatible with the cultivated host
Lactuca sativa
. Our previous studies on NHR in one
L. saligna
accession led to the hypothesis that multi-locus epistatic interactions might explain NHR. Here, we studied NHR at the species level in nine accessions. Besides the commonly used approach of studying a target trait from a wild donor species in a cultivar genetic background, we also explored the opposite, complementary approach of cultivar introgression in a wild species background. This bidirectional approach encompassed (1) nonhost into host introgression: identification of
L. saligna
derived chromosome regions that were overrepresented in highly resistant BC1 plants (F1 ×
L. sativa
), (2) host into nonhost introgression: identification of
L. sativa
derived chromosome regions that were overrepresented in BC1 inbred lines (F1 ×
L. saligna
) with relatively high infection levels. We demonstrated that NHR is based on resistance factors from
L. saligna
and the genetic dose for NHR differs between accessions. NHR seemed explained by combinations of epistatic genes on three or four chromosome segments, of which one chromosome segment was validated by the host into nonhost approach.
The objective of this study was to evaluate the sub-lethal toxicity of hexabromocyclododecane (HBCDD) in fish. Adult Chinese rare minnows as in vivo models were exposed to waterborne HBCDD from 1 to ...500
μg/l for 14, 28 and 42 days. Hepatic CYP1A1 (ethoxyresorufin-
O-deethylase, EROD) and CYP2B1 (pentaoxyresorufin-
O-depentylase, PROD) activities were measured. At the same time, molecular biomarkers of oxidative stress were also assayed in the brain, including reactive oxygen species (ROS), lipid peroxidation products (thiobarbituric acid-reactive substances, TBARS), DNA damage and protein carbonyl, as well as superoxide dismutase (SOD) activity and glutathione (GSH) content. DNA damage was evaluated using the Comet assay on erythrocytes. Besides, the content of HBCDD in whole fish was determined after 42 days exposure. The results show that HBCDD could induce EROD and PROD at 500
μg/l after 28 days exposure, and at 100 to 500
μg/l after 42 days exposure (
P
<
0.05), respectively. ROS formation in fish brain was observed to be increased in both time- and dose-dependent manner due to HBCDD exposure. The significant increases in TBARS and protein carbonyl contents occurred in fish brain after 28 and 42 days exposure (
P
<
0.05). Significant DNA damage in erythrocytes by Comet assay was also found in the 100–500
μg/l exposure groups (
P
<
0.05) after 42 days exposure. Moreover, significant depletion in brain GSH content occurred in all treated groups (
P
<
0.05) and apparent inhibition in SOD activity in brain was observed in the groups of 10–500
μg/l concentrations during 42 days exposure. The results demonstrate that increasing duration of HBCDD exposure induced EROD and PROD activities, caused excess ROS formation, finally resulted in oxidative damage to lipids, proteins and DNA and decreased antioxidant capacities in fish. Chemical analysis of HBCDD in whole fish showed accumulation up to 654
μg/g wet weight.
Centromeres are the chromosomal sites of assembly for kinetochores, the protein complexes that attach to spindle fibers and mediate separation of chromosomes to daughter cells in mitosis and meiosis. ...In most multicellular organisms, centromeres comprise a single specific family of tandem repeats-often 100-400 bp in length-found on every chromosome, typically in one location within heterochromatin.
is unusual in that the heterochromatin contains many families of mostly short (5-12 bp) tandem repeats, none of which appear to be present at all centromeres, and none of which are found only at centromeres. Although centromere sequences from a minichromosome have been identified and candidate centromere sequences have been proposed, the DNA sequences at native
centromeres remain unknown. Here we use native chromatin immunoprecipitation to identify the centromeric sequences bound by the foundational kinetochore protein cenH3, known in vertebrates as CENP-A. In
, these sequences include a few families of 5- and 10-bp repeats; but in closely related
, the centromeres comprise more complex repeats. The results suggest that a recent expansion of short repeats has replaced more complex centromeric repeats in
.
Similar to other neurodegenerative diseases, Parkinson's disease (PD) has been extensively investigated with respect to its neuropathological background and possible treatment options. Since the ...symptomatic outcomes are generally related to dopamine deficiency, the current treatment strate-gies towards PD mainly employ dopaminergic agonists as well as the compounds acting on dopamine metabolism. These drugs do not provide disease modifying properties; therefore alternative drug dis-covery studies focus on targets involved in the progressive neurodegenerative character of PD. This study has aimed to present the pathophysiology of PD concomitant to the representation of drugs and promising molecules displaying activity against the validated and non-validated targets of PD.
Purpose. The study aims to examine the effect of auditor quality on real activity manipulation. Result. The population is 20 state-owned enterprises (SOEs) listed on the Indonesia Stock Exchange for ...the period 2018–2020. Using the purposive sampling method, 57 observations for the specified period were obtained. Next, we used a linear regression model as the method. The results showed that auditor quality had no effect on real activity manipulation through abnormal Operating Cash Flow (CFO), abnormal Production Costs (PROD) and abnormal Discretionary Expenses (DISC). Auditor quality has no effect on real activity manipulation through abnormal CFO. This is because the auditor’s independence attitude decreases which causes management to manipulate real activities through abnormal CFO, namely by increasing the company’s sales value. Auditor quality has no effect on real activity manipulation through abnormal PROD. This is because a qualified auditor in the company is only a formality to provide assurance in the eyes of investors that the company is in good condition. So, management will manipulate real activities through abnormal PROD, namely increasing the company’s production. Auditor quality has no effect on real activity manipulation through abnormal DISC. This is because the client’s accounting flexibility from qualified auditors is hampered, where management will change earnings management by using real activity manipulation through abnormal DISC, namely reducing discretionary costs. Scientific novelty. This research is based on the application of the already known methodology and design developed by Sanjaya, the difference is that in this study we used SOEs as the object. Moreover, we employed different period from prior study which are in the year of 2018 to 2020. Also, this study uses agency theory because this is based on information asymmetry between the principal and agent, which overall indicates a certain novelty of our work. Practical value. The results of this study are useful for assessing the quality of auditors in increasing the credibility of financial statements to reduce risks that occur in financial statements such as real earnings management through abnormal CFO, abnormal PROD, and abnormal DISC. Prospects for its development are by expanding and adding objects and years, as well as used variables.
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