Black spots could be induced in red tilapia at wintering stage. This body color variation causes significant economic loss to the aquaculture industry of red tilapia. Understanding the genetic ...architecture of wintering black spot variation is of great significance for the selection of pure red tilapia lines. In this study, 37 SNPs and five QTLs controlling for the wintering black spot trait at genome-wide significance were successfully identified on Chr2:4.6–4.9 Mb, Chr2:20.0 Mb, Chr3:30.1–34.0 Mb, Chr8:4.0–6.1 Mb, Chr12:5.9–7.5 Mb in red tilapia (N = 287) by using a genome-wide association study. These QTLs were further verified by genotyping four novel microsatellite markers in the mapping population. Three candidate genes (sema-4c, uvssa and htr2cl1) in these QTL regions showed significantly differentiated expression in response to low temperature (LT) or UVB or UVB + LT challenges in brain or skin tissues of red tilapia as revealed by qRT-PCR analysis. Interestingly, the expression levels of the three candidate genes were more significantly changed under the UVB+ LT stressors than the LT or UVB stress solely. These suggested that the wintering black spots in red tilapia may be regulated by comprehensive environmental factors.
•37 SNPs associated with wintering black spot trait were successfully identified in red tilapia.•QTLs were verified in the mapping population using four microsatellite markers.•Three candidate genes showed significant responses to challenges in red tilapia.
•Performed microstructural analysis of black spots on bronze artefacts.•Black spots comprised metallic copper and fine particle mixtures of Cu2S and CuSO4.•H2S and COS originated from ...underwater-excavated artefacts in the exhibition case.•H2S and COS can be reduced using deoxygenating and dehumidifying agents (RP-AN).
While deterioration due to the generation of “black spots” is reported, consensus on the specific corrosion products comprising black spots and underlying deterioration mechanisms is lacking. This study investigated the deterioration of copper objects by analysing the black spots that appeared on them and proposes environmental conditions to suppress the appearance of black spots. Bronze artefacts excavated from a marine archaeological site, on which black spots were generated, were closely observed, and investigated. First, X-ray fluorescence and micro-X-ray diffraction analyses were performed on a bronze artefact, from which the black spots were removed, to determine the composition of the artefact. Second, to investigate the composition of the black spots, fine structure analysis of the black spots on the fine fragments of the bronze artefacts was conducted using scanning and transmission electron microscopy, energy dispersive X-ray spectroscopy, and electron diffraction (ED) analysis. The results indicate that the black spots were partially composed of metallic copper and a fine particle mixture of Cu2S and CuSO4. These results imply that the transformation of copper sulfide to metallic copper may have played an important role in the initiation and propagation of black spots. In this study, ED analysis was performed on the microscopic area of the black spots; no amorphous phases were detected, and all observed phases were identified as crystalline materials. To determine the sources of gas-phase sulfur compounds that cause black spots, H2S and carbonyl sulfide (COS) emissions from a spherical clay artefact (a cannon ball with gunpowder excavated from an underwater archaeological site) which was exhibited in the same showcase with the bronze artefacts were analysed via gas chromatography. The concentrations of H2S and COS were 0.462 and 8.636 ppb, respectively; these are significantly higher than those in the lower troposphere. These results indicate that deterioration by black spots occurred because of H2S and COS, which were emitted from the spherical clay artefact excavated from an underwater archaeological site in the exhibition case. In addition, it was confirmed that the inclusion of deoxygenating and dehumidifying agents (RP-AN) in the plastic bag in which the spherical clay artefact was inserted resulted in a significant decrease in the concentration of H2S and COS.
Objective The recently reported endoscopic finding of black spots is defined as black pigmentation in gastric mucosa. We attempted to clarify the relationship between the Helicobacter pylori ...infection status and black spot occurrence. Subjects and methods The study subjects were 1,600 individuals who underwent an annual medical checkup and whose H. pylori status could be determined. Upper endoscopic examinations were performed in all, and the presence of black spots in the stomach as well as the degree of gastric mucosal atrophy were determined. Results Among the 1,600 enrolled subjects, 784 underwent eradication for H. pylori, of whom 144 were originally H. pylori-positive and 672 H. pylori-negative. Black spots in the stomach were observed in 156 (9.8%). The rate of prevalence of black spots in the H. pylori-positive and H. pylori-negative subjects was 2.1% and 1.5%, respectively, while that in subjects after undergoing eradication of H. pylori was 18.2%. A multiple logistic regression analysis demonstrated that an older age and post-eradication status were significant factors for black spot occurrence, while proton pump inhibitor treatment showed a tendency to be a risk factor. In subjects with post-eradication status, a higher grade of gastric mucosal atrophy was a significant risk factor for the occurrence of black spots. Conclusion H. pylori post-eradication status and an older age were significant factors related to the appearance of black spots, and a higher grade of gastric mucosal atrophy was also a significant risk factor in subjects who had undergone successful eradication.
Melanized focal changes in white skeletal muscle of farmed Atlantic salmon, "black spots", is a quality problem affecting on average 20% of slaughtered fish. The spots appear initially as "red spots" ...characterized by hemorrhages and acute inflammation and progress into black spots characterized by chronic inflammation and abundant pigmented cells.
1 (PRV-1) was previously found to be associated with macrophages and melano-macrophages in red and black spots. Here we have addressed the inflammatory microenvironment of red and black spots by studying the polarization status of the macrophages and cell mediated immune responses in spots, in both PRV-1 infected and non-infected fish. Samples that had been collected at regular intervals through the seawater production phase in a commercial farm were analyzed by multiplex fluorescent
hybridization (FISH) and RT-qPCR methods. Detection of abundant inducible nitric oxide synthase (iNOS2) expressing M1-polarized macrophages in red spots demonstrated a pro-inflammatory microenvironment. There was an almost perfect co-localization with the iNOS2 expression and PRV-1 infection. Black spots, on the other side, had few iNOS2 expressing cells, but a relatively high number of arginase-2 expressing anti-inflammatory M2-polarized macrophages containing melanin. The numerous M2-polarized melano-macrophages in black spots indicate an ongoing healing phase. Co-localization of PRV-1 and cells expressing CD8
and MHC-I suggests a targeted immune response taking place in the spots. Altogether, this study indicates that PRV-1 induces a pro-inflammatory environment that is important for the pathogenesis of the spots. We do not have indication that infection of PRV-1 is the initial causative agent of this condition.
To develop a successful strategy for improving road safety, the initial step involves is to identify the black spots that are more susceptible to high-risk traffic accidents. However, due to the high ...cost of implementing safety measures in these locations, only a limited number of spots/sites can be thoroughly examined with the available funding. Therefore, it is crucial to prioritize the high-risk sites and their corresponding safety measures in order to make the most efficient use of the available finances. Hence, this paper presents black spots ranking and low-cost countermeasures based on the Perak Federal trunk road traffic crash (RTC) data for three years from 2018 to 2020 recorded by the Royal Malaysian Police (RMP). The weightage point method was used for each black spot ranking exercise where as, the selection for countermeasures were based on RTC situations which are norms practiced by the Public Works Department (PWD). In total 22 black spots were ranked and it was found that the highest rank of the 2020 black spots in Perak was along route FT005 in Kinta district which had 18 RTCs and with a total weightage points (TWP) of 118.2. In balancing between limited financial allocation and improving road safety, the countermeasures were priorotized for implementation in 2021 based on the black spots ranking results. However, only six black spots were treated in 2021 with the entire cost was RM 1,834,027.19. Where for route FT005 in Kinta district, the countermeasure was done at Section 684 with a total cost of RM350,000 under the 2022 black spots countermeasure program which is an annual program funded by the Ministry of Works Malaysia. It is recommended that Perak State PWD form a Road Safety Unit to reduce the black spots along the state roads which is the second highest road fatalities recorded in Perak.
Fatal hypothermia represents a diagnostic challenge in veterinary pathology. Wischnewski spots (WS) and black oesophagus (BO) have been described in human cases of fatal hypothermia but rarely in ...animals. We now describe WS and BO in suspected fatal hypothermia in a free-ranging brown howler monkey (Alouatta guariba clamitans) and a pet rabbit (Oryctolagus cuniculus). Both animals had dark spots resembling WS on the gastric mucosa and the monkey also had BO with haematin deposition. In both cases, stress factors and relatively cold environmental conditions were present prior to death.
The influence of electropulsing treatment on black spots in Ti-5Al-5Mo-5 V-1Cr-1Fe titanium alloy has been investigated. Comparing samples processed by electropulsing heat treatment (EHT) with the ...sample heated by conventional heat treatment (CHT), the recovery and recrystallization of the black spots regions are greatly accelerated by EHT. It is also found that the micro-hardness of the CHT sample is almost the same as that of the received one. While the micro-hardness of EHT sample is smaller than CHT one, and increased with increasing joule temperature.
•Electropulsing treatment is used to eliminate black spot defects.•Electropulsing treatment greatly accelerates the the recovery and recrystallization.•Micro-hardness increases with the increase of the electropulsing treatment temperature.
Recently, in Russia, it has become relevant to conduct “audits of black spots”. It is a type of an independent audit and evaluation of the traffic safety level in the location under survey, ...determination of patterns in road accident causes and corresponding measures for their prevention. Traffic safety can be evaluated based on various criteria, but the reduction of the number of road accidents, especially those with injuries, has always been the most important criterion of traffic safety. In this paper, an analysis of factors that can affect elements of subsystems and the traffic safety system, in general, is conducted. Practical recommendations are provided.
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