Fish Eye Research Articles

Molecular Characterization and Possible Immune Function of Two Members of Interleukin Family from Trachinotus ovatus

Interleukins (ILs) are a group of cytokines which play a core regulatory role in the immune system. In the present study, two members of the IL family, IL7 and IL8, were detected in Trachinotus ovatus. IL7 and IL8 cDNAs of T. ovatus consist of a 492 bp and 300 bp ORF (open reading frame) encoding a polypeptide of 163 and 99 amino acids, respectively. Multiple sequence alignment revealed that IL7 and IL8 contain characteristic arrangements of several conserved cysteine residues, which in T. ovatus are in positions 20, 57, 67, 105, 140, 152 and 35, 37, 61, 78, respectively. The phylogenetic tree showed that all ILs fell into four categories. Moreover, IL7 and IL8 mRNA of T. ovatus were constitutively expressed at different levels in all examined tissues, except muscle. Transcripts of IL7 were mainly expressed in liver, intestine, kidney, stomach, and fin, while transcripts of IL8 were highly detected in the eye, liver, kidney, and intestine of healthy fish. After Photobacterium damselae innoculation, mRNA levels of IL7 were higher than IL8 in the spleen and intestine, however, mRNA expression levels of IL7 were lower than IL8 in kidney 3 h post-injection. These results suggest that the two IL molecules play an important role in the inflammatory response of T. ovatus.

Epigenetic, histopathological and transcriptomic effects following exposure to depleted uranium in adult zebrafish and their progeny

This study investigated the effects of adult zebrafish exposure to a nominal concentration of 20μgL−1 of depleted uranium (DU) for six days upon DNA methylation, gene expression and the appearance of histopathological damage in their progeny. In the embryos at the 2–8 cell stage, the parental exposure induced significant DU accumulation, with levels seven times higher than those measured in the control embryos, but in larvae 96h post-fertilisation (hpf), uranium concentration had already returned to a level identical to that of the control larvae. A significant two-fold increase in the global level of DNA methylation was observed in embryos as early as the prim5 (24 hpf) stage and was still maintained at the 96 hpf stage despite the fact that DU had already been depurated at the later stage. RNA sequencing analysis indicated an impact of parental exposure upon the total RNAs transmitted from the mother to eggs, and the up-regulated genes were those associated with post-traductional protein modification and trafficking and cellular signalling pathways, whereas the down-regulated genes concerned the translational process, cell cycle regulation and several cell signalling pathways. Alterations of photoreceptor cells and the axon-axon junctions between photoreceptors were observed in the eyes of adult fish exposed for 10days to DU. Actin and myosin filament disorganisation was observed in the skeletal muscles of 96 hpf larvae, at a stage when the maternally transmitted DU had already been excreted. These data reveal the extreme sensitivity of zebrafish embryos to DU transmitted through the oocyte by exposed females.

Fatigue Crack Surface Topography after Plasma Nitriding Process

Fatigue characteristics of steel 41CrAlMo7-10 and topography analysis testing methodology of fish eye were studied. Both sets of samples were heat-treated at the same conditions and subsequently were plasma nitrided. The mixture ratio of these main gases, forming the atmosphere during the plasma nitriding was inverted for both sets of samples. Process parameters such as the duration, the applied voltage and the pulse length were identical for all samples. Following test after heat treatment and surface layer formation by plasma nitriding process for both sets of samples was the <em>rotating bending fatigue testing</em> in the machine R.R.Moore L2568 of Instron Co. The fatigue tests were carried out in accordance with the CSN 42 0363 Fatigue Testing of Metals, Methodology of Testing. Then, tests were evaluated numerically and graphically using Wöhler`s (S-N) curve in a semi-logarithmic form. The testing was stopped after reach the fracture of tested sample or after 107 cycles. The surface topography of fatigue cracks were evaluated on Talysurf CCI. The topography analysis was mainly focused on the initial part of fatigue crack called the fish-eye. The topography analysis was performed only on one selected sample of each series.

Nanograin layer formation at crack initiation region for very‐high‐cycle fatigue of a Ti–6Al–4V alloy

AbstractThe microstructural features and the fatigue propensities of interior crack initiation region for very‐high‐cycle fatigue (VHCF) of a Ti–6Al–4V alloy were investigated in this paper. Fatigue tests under different stress ratios of R = −1, −0.5, −0.1, 0.1 and 0.5 were conducted by ultrasonic axial cycling. The observations by SEM showed that the crack initiation of VHCF presents a fish‐eye (FiE) morphology containing a rough area (RA), and the FiE and RA are regarded as the characteristic regions for crack initiation of VHCF. Further examinations by TEM revealed that a layer of nanograins exists in the RA for the case of R = −1, while nanograins do not appear in the FiE outside RA for the case of R = −1, and in the RA for the case of R = 0.5, which is explained by the Numerous Cyclic Pressing model. In addition, the estimations of the fatigue propensities for interior crack initiation stage of VHCF indicated that the fatigue life consumed by RA takes a dominant part of the total fatigue life and the related crack propagation rate is rather slow.

Biochemical and Histopathological Changes Induced by Nickel in the Striped Mullet, Mugil cephalus (Linnaeus 1758).

The present study is focused on determining the acute and chronic toxicity of nickel (Ni) to fish fingerlings, Mugil cephalus. The 96-h median lethal concentration (LC50) for Ni was found to be 42.2 ± 3.9mgL-1. Based on the chronic toxicity test for 30 days, "No Observed Effect Concentration", "Lowest Observed Effect Concentration" and "Chronic value" were found to be 2.9 ± 0.14, 4.7 ± 0.14 and 3.7 ± 0.14mg Ni L-1, respectively. The activities of biomarker enzymes including esterase, superoxide dismutase and malate dehydrogenase showed differential expression and cellular anomalies like hyperplasia and detachment of bipolar cells from photoreceptor cells in the retina of eye of mullet. Cellular anomalies in the retina of fish eye affect the primary function of retina, which is to convert light energy into nerve impulses transferred to the brain via the optic nerve, leading to loss or poor vision.

Microhabitat Selection and Eyefluke Infection Levels in the Western Mosquitofish (Gambusia affinis).

Several trematode species infect the eyes of fish as second intermediate hosts. In most cases the definitive host is a piscivorous bird. Studies of a few species have shown an increase in transmission due to decreased visual acuity of the fish host. However, this may vary depending on trematode microhabitat choice within the eye. Some trematode species are found in the lens, some are found in the vitreous humor, and others have been reported from the retina. Here we report 3 genera of eyeflukes in 3 locations of the eye in the intermediate fish host, Gambusia affinis . Clinostomum metacercariae were found attached to the outer sclera within the eye orbit, and Diplostomum metacercariae were found in the lens. Posthodiplostomum metacercariae were confirmed by histology to reside between the choroid and pigmented retina. Posthodiplostomum metacercariae were found in both eyes of all 20 fish examined and in high intensities (up to 27 metacercariae per eye). High trematode intensities between the choroid and pigmented retina found in this study may disrupt vision in this fish host. Our study is the first to document the microhabitat of all 3 trematode metacercariae within the eye of G. affinis .

Measurement of polyp size at colonoscopy: a proof-of-concept simulation study to address technology bias

We introduce a novel, proof-of-concept polyp measurement device for the design of future colonoscopes. In a simulation study, 50 expert endoscopists used three measurement strategies (method 1: no visual cues;...

Intraductal Papillary Mucinous Neoplasm of the Minor Pancreatic Duct in Pancreas Divisum: A Case Report

Intraductal papillary mucinous neoplasms (IPMN) are potentially malignant intraductal epithelial neoplasms that are composed of mucin-producing columnar cells. The lesions show papillary proliferation, cyst formation, and may involve the main pancreatic duct, the branch ducts, or both. IPMNs have varying degrees of malignant potential based on anatomic location, with main duct lesions progressing in 38-68% of cases. Therefore, surgical removal is indicated for these types of lesions. Most patients are asymptomatic and incidental diagnosis is made with advances in imaging and endoscopic procedures. Here we report a case of a 66-year-old male with a history of pancreas divisum and family history of pancreatic cancer who presented with pancreatitis. Initial symptoms were progressively worsening mid-epigastric pain with elevated amylase and lipase levels. After initial medical treatment for his pancreatitis, further evaluation with upper endoscopy showed a patulous minor papilla with a “fish eye” appearance that excreted mucin. Endoscopic ultrasound identified a markedly dilated pancreatic duct in addition to an anatomic variation called pancreas divisum. Subsequent ERCP with SpyGlass DS pancreatoscopy revealed a papillary lesion at the junction of the head and body of the pancreas. Biopsy confirmed the diagnosis of this main duct IPMN. Pancreatic divisum is an anatomic variant which results when the embryologic dorsal and ventral pancreatic ducts fail to fuse properly. Our background research revealed only a few reported cases of IPMN and pancreas divisum occurring in tandem. It has been noted that IPMN in the setting of pancreas divisum carries a higher rate of malignancy. Surgical intervention based on the Sendai and Fukuoka consensus is appropriate for IPMNs and is indicated in main duct IPMN in the setting of pancreas divisum, since these patients have better survival with surgical removal. This case emphasizes the need to appropriately evaluate patients presenting with pancreatitis, as there is a possibility of an underlying malignant process.

Aging asymmetry: systematic survey of changes in age-related biomarkers in the annual fish Nothobranchius guentheri.

Aging asymmetry is the observation that different tissues age in different ways and at different rates. This has not been assessed in a single organism using multiple biomarkers of aging. Here we clearly demonstrated that the levels of protein oxidation and lipid peroxidation as well as CAT, SOD and GPX activities all showed a tissue-dependent change with advancing age; and DNA repair ability, as revealed by the expression of ercc1 and its protein levels, also exhibited a tissue-specific variation with age. We also found that protein oxidation and lipid peroxidation levels remained relatively stable in the liver, intestine, skin and testis as well as in the brain, eye and heart of young, adult and aged fishes; SOD and GPX activities displayed little variation in the intestine, eye and skin as well as in the brain and skin of young, adult and aged fishes; and low and stable expression of ercc1 was observed in the spleen, eye and heart of young, adult and aged fishes. Collectively, these results indicate that aging is tissue specific and asymmetric in N. guentheri. The observation of aging asymmetry may have practical implications for the application of non-intrusion intervention approaches to prolong lifespan.

Colour thresholds in a coral reef fish.

Coral reef fishes are among the most colourful animals in the world. Given the diversity of lifestyles and habitats on the reef, it is probable that in many instances coloration is a compromise between crypsis and communication. However, human observation of this coloration is biased by our primate visual system. Most animals have visual systems that are ‘tuned’ differently to humans; optimized for different parts of the visible spectrum. To understand reef fish colours, we need to reconstruct the appearance of colourful patterns and backgrounds as they are seen through the eyes of fish. Here, the coral reef associated triggerfish, Rhinecanthus aculeatus, was tested behaviourally to determine the limits of its colour vision. This is the first demonstration of behavioural colour discrimination thresholds in a coral reef species and is a critical step in our understanding of communication and speciation in this vibrant colourful habitat. Fish were trained to discriminate between a reward colour stimulus and series of non-reward colour stimuli and the discrimination thresholds were found to correspond well with predictions based on the receptor noise limited visual model and anatomy of the eye. Colour discrimination abilities of both reef fish and a variety of animals can therefore now be predicted using the parameters described here.

Losing focus: how lens position and viewing angle affect the function of multifocal lenses in fishes.

Light rays of different wavelengths are focused at different distances when they pass through a lens (longitudinal chromatic aberration [LCA]). For animals with color vision this can pose a serious problem, because in order to perceive a sharp image the rays must be focused at the shallow plane of the photoreceptor's outer segments in the retina. A variety of fish and tetrapods have been found to possess multifocal lenses, which correct for LCA by assigning concentric zones to correctly focus specific wavelengths. Each zone receives light from a specific beam entrance position (BEP) (the lateral distance between incoming light and the center of the lens). Any occlusion of incoming light at specific BEPs changes the composition of the wavelengths that are correctly focused on the retina. Here, we calculated the effect of lens position relative to the plane of the iris and light entering the eye at oblique angles on how much of the lens was involved in focusing the image on the retina (measured as the availability of BEPs). We used rotational photography of fish eyes and mathematical modeling to quantify the degree of lens occlusion. We found that, at most lens positions and viewing angles, there was a decrease of BEP availability and in some cases complete absence of some BEPs. Given the implications of these effects on image quality, we postulate that three morphological features (aphakic spaces, curvature of the iris, and intraretinal variability in spectral sensitivity) may, in part, be adaptations to mitigate the loss of spectral image quality in the periphery of the eyes of fishes.

Operational Challenges and Monitoring of a Polymer Pilot, Matzen Field, Austria

Summary Four main areas of uncertainty can be described in polymer-injection projects: Are we able to deliver the polymer solutions at the required quality to the wellhead? Are we able to inject polymers at the required quantity and quality? Are we producing sufficient incremental oil? Are we able to separate and treat oil and water cost-effectively after polymer breakthrough? The monitoring program that was developed for the polymer-injection pilot aims to reduce the uncertainty and quickly identify operational difficulties, as described in the following: Polymer quality at the wellhead: The polymer concentration and viscosity of the “source” solution and injected polymer solution were measured at various locations in the surface facilities. A quality check of the delivered polymer (including a filter ratio test of the dissolved polymer) was performed, the biological activity monitored, iron content measured, and polymer solution investigated for “fish eyes.” The monitoring program enabled us to identify challenges related to shearing the polymers after changing the operating envelope, to identify problems related to biological activity, and to ensure data quality for interpretation of the pilot. Injectivity and degradation: Monitoring involved wellhead- and bottomhole-pressure measurements, repeated falloff tests, and visual observation of the polymer solutions in the well. The results showed the mobility reduction of the polymer solutions and an indication of induced fractures. Combining the various measurements led to identification of an operational issue—the injectivity decreased more than expected from polymer rheology and prepilot water-quality assessment. The reason was the combination of fines and small oil droplets existing in the injection water with polymer- and biological-generated mass that plugged the pores during injection. Incremental oil: Accurate measurement of the produced-water cut, especially for those wells producing at water cuts greater than 90%, is key for reporting accurate incremental oil. In addition, water salinity at the producing wells was measured, and a repeated tracer program was instituted. The results have been used to assess the reservoir architecture and incremental oil related to polymer injection. The challenges in the interpretation of the pilot conformance could be resolved by use of these data. Polymer, oil, water treatment: The surface facilities are monitored constantly for separation efficiency and plugging owing to back-produced polymers. Operating challenges are seen in all treatment steps for full-field polymer-injection implementation because of both oil/water separation and handling of the polymers in water-treatment facilities.

The Identification of Fish Eyes Imagery to Determine the Quality of Fish Meat Based on Fuzzy Logic Method

The quality of sorting fish meat is required before processing because the fish whose quality is bad will affect the quality of the good fish if processed simultaneously. The classification process manually not only need a long time but also produces the inconsistent product quality. In this research, the selection of fish as an object because the fish which sold in modern and traditional market is dies, so that people do not know the quality of the fish that will be purchased. Because of that, this research tries to classification of the fish meat freshness automatically using HSV color features and Grayscale with classification method using fuzzy logic. Using fuzzy logic method is because it was considered to be able to resolve the problems are not linier. The fish image of the results of image acquisition will go through the process of preprocessing is a Contrast stretching processes, cropping and scaling, after that the fish eyes imagery will be through the feature extraction process, features that is used is a HSV color feature and Grayscale. The final process is classification using Fuzzy Logic method. The classification of the freshness of fish meat are fresh fish, fish that good enough and the fish in a bad condition are using samples of each 50 fish and using 3 types of fish. That are kembung, tongkol, and bandeng fish. The parts of fish that researched is eye. On the fish eye, the eye color is changes when fish is in a bad condition. From the results of the classification program using the GUI method can be determined the classification result process with accuracy of the overall system in kembung fish is 93%, bandeng fish is 89%, and tongkol fish is 88%. The classification result of the freshness of fish meat using a fish eye imagery based on fuzzy logic method has a good result.

BUDGET UAV SYSTEMS FOR THE PROSPECTION OF SMALL- AND MEDIUM-SCALE ARCHAEOLOGICAL SITES

Abstract. One of the popular uses of UAVs in photogrammetry is providing an archaeological documentation. A wide offer of low-cost (consumer) grade UAVs, as well as the popularity of user-friendly photogrammetric software allowing obtaining satisfying results, contribute to facilitating the process of preparing documentation for small archaeological sites. However, using solutions of this kind is much more problematic for larger areas. The limited possibilities of autonomous flight makes it significantly harder to obtain data for areas too large to be covered during a single mission. Moreover, sometimes the platforms used are not equipped with telemetry systems, which makes navigating and guaranteeing a similar quality of data during separate flights difficult. The simplest solution is using a better UAV, however the cost of devices of such type often exceeds the financial capabilities of archaeological expeditions. The aim of this article is to present methodology allowing obtaining data for medium scale areas using only a basic UAV. The proposed methodology assumes using a simple multirotor, not equipped with any flight planning system or telemetry. Navigating of the platform is based solely on live-view images sent from the camera attached to the UAV. The presented survey was carried out using a simple GoPro camera which, from the perspective of photogrammetric use, was not the optimal configuration due to the fish eye geometry of the camera. Another limitation is the actual operational range of UAVs which in the case of cheaper systems, rarely exceeds 1 kilometre and is in fact often much smaller. Therefore the surveyed area must be divided into sub-blocks which correspond to the range of the drone. It is inconvenient since the blocks must overlap, so that they will later be merged during their processing. This increases the length of required flights as well as the computing power necessary to process a greater number of images. These issues make prospection highly inconvenient, but not impossible. Our paper presents our experiences through two case studies: surveys conducted in Nepal under the aegis of UNESCO, and works carried out as a part of a Polish archaeological expedition in Cyprus, which both prove that the proposed methodology allows obtaining satisfying results. The article is an important voice in the ongoing debate between commercial and academic archaeologists who discuss the balance between the required standards of conducting archaeological works and economic capabilities of archaeological missions.

Fatigue properties and microstructure of quasicrystalline AlFeCrTi alloy

Aluminium based material having chemical composition of Al93Fe3Ti2Cr2 (at.%) was prepared by hot extrusion of gas atomised powder. Microstructure consisting of aluminium matrix and icosahedral quasicrystalline particles was investigated by scanning and transmission electron microscopy a X-ray spectroscopy. Size, distribution and inner structure of quasicrystalline particles were determined. When quasicrystalline particles having submicron size were present in the microstructure together with fine-grained aluminium matrix, it resulted in enhancement of mechanical properties. Fatigue experiments were performed in load controlled regime with positive mean stress and fatigue life data for this quasicrystalline material were compared with similar results for commercially available aluminium alloys. Longer fatigue life together with higher fatigue strength reaching value of 350MPa was observed. It is approx. 100MPa higher than for commercially produced coarse-grained aluminium alloys. Fractographic observations revealed presence of fish eye fracture patterns and validity of weakest link fracture mechanism acting in this type of material under investigation.

BUDGET UAV SYSTEMS FOR THE PROSPECTION OF SMALL- AND MEDIUM-SCALE ARCHAEOLOGICAL SITES

One of the popular uses of UAVs in photogrammetry is providing an archaeological documentation. A wide offer of low-cost (consumer) grade UAVs, as well as the popularity of user-friendly photogrammetric software allowing obtaining satisfying results, contribute to facilitating the process of preparing documentation for small archaeological sites. However, using solutions of this kind is much more problematic for larger areas. The limited possibilities of autonomous flight makes it significantly harder to obtain data for areas too large to be covered during a single mission. Moreover, sometimes the platforms used are not equipped with telemetry systems, which makes navigating and guaranteeing a similar quality of data during separate flights difficult. The simplest solution is using a better UAV, however the cost of devices of such type often exceeds the financial capabilities of archaeological expeditions. <br><br> The aim of this article is to present methodology allowing obtaining data for medium scale areas using only a basic UAV. The proposed methodology assumes using a simple multirotor, not equipped with any flight planning system or telemetry. Navigating of the platform is based solely on live-view images sent from the camera attached to the UAV. The presented survey was carried out using a simple GoPro camera which, from the perspective of photogrammetric use, was not the optimal configuration due to the fish eye geometry of the camera. Another limitation is the actual operational range of UAVs which in the case of cheaper systems, rarely exceeds 1 kilometre and is in fact often much smaller. Therefore the surveyed area must be divided into sub-blocks which correspond to the range of the drone. It is inconvenient since the blocks must overlap, so that they will later be merged during their processing. This increases the length of required flights as well as the computing power necessary to process a greater number of images. <br><br> These issues make prospection highly inconvenient, but not impossible. Our paper presents our experiences through two case studies: surveys conducted in Nepal under the aegis of UNESCO, and works carried out as a part of a Polish archaeological expedition in Cyprus, which both prove that the proposed methodology allows obtaining satisfying results. The article is an important voice in the ongoing debate between commercial and academic archaeologists who discuss the balance between the required standards of conducting archaeological works and economic capabilities of archaeological missions.

Involvement of microbial mats in early fossilization by decay delay and formation of impressions and replicas of vertebrates and invertebrates.

Microbial mats have been hypothesized to improve the persistence and the preservation of organic remains during fossilization processes. We test this hypothesis with long-term experiments (up to 5.5 years) using invertebrate and vertebrate corpses. Once placed on mats, the microbial community coats the corpses and forms a three-dimensional sarcophagus composed of microbial cells and exopolymeric substances (EPS). This coverage provides a template for i) moulding superficial features, resulting in negative impressions, and ii) generating replicas. The impressions of fly setulae, fish scales and frog skin verrucae are shaped mainly by small cells in an EPS matrix. Microbes also replicate delicate structures such as the three successive layers that compose a fish eye. The sarcophagus protects the body integrity, allowing the persistence of inner organs such as the ovaries and digestive apparatus in flies, the swim bladder and muscles in fish, and the bone marrow in frog legs. This study brings strong experimental evidence to the idea that mats favour metazoan fossilization by moulding, replicating and delaying decay. Rapid burial has classically been invoked as a mechanism to explain exceptional preservation. However, mats may play a similar role during early fossilization as they can preserve complex features for a long time.

Long-chain polyunsaturated fatty acid biosynthesis in the euryhaline herbivorous teleost Scatophagus argus: Functional characterization, tissue expression and nutritional regulation of two fatty acyl elongases.

Both the spotted scat Scatophagus argus and rabbitfish Siganus canaliculatus belong to the few cultured herbivorous marine teleost, however, their fatty acyl desaturase (Fad) system involved in long-chain polyunsaturated fatty acid (LC-PUFA) biosynthesis is different. The S. argus has a △6 Fad, while the rabbitfish has △4 and △6/△5 Fads, which were the first report in vertebrate and marine teleost, respectively. In order to compare the characteristics of elongases of very long-chain fatty acids (Elovl) between them, two Elovl cDNAs were cloned from S. argus in the present study. One has 885bp of open read fragment (ORF) encoding a protein with 294 amino acid (aa) showing Elovl5 activity functionally characterized by heterologous expression in yeast, which was primarily active for the elongation of C18 and C20 PUFAs. The other has 915bp of ORF coding for a 305 aa protein showing Elovl4 activity, which was more efficient in the elongation of C20 and C22 PUFAs. Tissue distribution analyses by RT-PCR showed that elovl5 was highly expressed in the liver compared to other tissues determined, whereas elovl4 transcripts were only detected in the eye. The expression of elovl5 and elovl4 were significantly affected by dietary fatty acid composition, with highest expression of mRNA in the liver and eye of fish fed a diet with an 18:3n-3/18:2n-6 ratio of 1.7:1. These results indicated that the S. argus has a similar Elovl system in the LC-PUFA biosynthetic pathway to that of rabbitfish although their Fad system was different, suggesting that the diversification of fish LC-PUFA biosynthesis specificities is more associated with its Fad system. These new insights expand our knowledge and understanding of the molecular basis and regulation of LC-PUFA biosynthesis in fish.

A Novel Idea for Freshness Analysis and Classification of Iced Sea Fish

Fish is a source of food for many species including human. It has been an important source of protein and other nutrients for human. Fresh fish are always better for preparing healthy and tasty food. Analysis of fresh fish is an important aspect to get the best quality of the fish for the preparation of healthy food. Sensory evaluation method is usually practiced in fish industry which involves judging of freshness by smell, color, appearance, taste and texture. The validity of this evaluation method has been questioned due to general parameters. In this study we are developing an evaluation method by using image processing of the fish eye. The fish eye image will be captured on different days and it is analyzed by using image processing tools to evaluate its freshness. The analysis will give the freshness index and classification of fish species used in this study. A series of fish images of different days is uploaded, the classification will be done and the result is presented in the excel sheet. In this study we use image processing tools to analyze the freshness of the sea fish. The analysis will be done on 2 species of fish. Initially the eye image of the fish is captured on different days and kept in the database. The images are segmented and its features are extracted. Classification of the image is done and a database is created as per the image captured on different days. KNN Algorithm is used for the classification. When a series of fish images are given as an input to the modeled device, it will crops its eye part, extracts the features and compares with the database. Fishes are classified into different grades and results are stored in the excel sheet to identify their grades. II. Proposed System The Proposed system consists of two stages. Stage one is to capture the images for creating database and in stage two a series of test images are given for classification based on database. In this system two species of fish, King Fish and Makrel are used for the freshness analysis. The images of two fish are captured and stored in day one. The process is repeated in day two, day three with the same setup. The required images are stored in the database. The eye part is extracted by image segmentation process and its features are obtained and stored in database. If a series of fish images of different days is given as the input for the model it will compare with the database and classify them according to their grades and the results are stored in the excel sheet. The block diagram of the proposed system is as shown below in Fig 1.

Structural and Biochemical Studies on the Activation Mechanism of Lecithin:Cholesterol Acyltransferase

Coronary heart disease (CHD) is the leading cause of death in the United States and is strongly associated with low levels of high density lipoprotein‐cholesterol (HDL‐C), thus there is significant clinical interest in methods that raise HDL‐C in order to treat and prevent CHD. Lecithin:cholesterol acyltransferase (LCAT) esterifies cholesterol on high density lipoprotein (HDL), which promotes HDL maturation and reverse cholesterol transport, the process by which cholesterol is transported from arterial plaques to the liver. Mutations in LCAT are known to cause two genetic diseases. Fish eye disease (FED) is characterized by partial loss of LCAT activity, whereas familial LCAT deficiency (FLD) is characterized by complete loss of LCAT. Individuals with either FED or FLD have low HDL‐C levels and corneal opacities, while FLD patients ultimately develop renal failure. Consequently, administration of recombinant LCAT and LCAT‐activating compounds are being investigated as treatments to increase HDL in both CHD and FLD, and have already shown promise in animal models. However, improvement of these therapeutics is limited due to a lack of structural information on LCAT and its interactions with HDL. LCAT is 50% identical to lysosomal phospholipase A2 (LPLA2). We previously solved a 1.84 Å structure of LPLA2, as well as a low‐resolution structure of LCAT (8.7 Å), both of which are in an active “lid open” conformation. In addition, structures of LPLA2 bound to inhibitors that mimic substrate binding led to models for how LPLA2 and LCAT bind to phospholipids and subsequently transfer an acyl group to the appropriate acceptor. Here we present a new “closed” crystal structure of LCAT at 3.3 Å wherein a retractable lid appears to block substrate access to the active site. Interestingly, the lid interacts with residues on the catalytic core that are mutated in LCAT genetic disease and are hypothesized to be important for activation by apolipoprotein A‐I (ApoA‐I), the major protein component of HDL particles. We therefore hypothesized that ApoA‐I binding will compete with the lid and thereby stimulate LCAT activity. We have probed the role of the lid by examining disease‐causing and lid mutations for esterase activity on a soluble substrate, binding to synthetic HDLs, and transacylase activity on HDLs. Overall, our results confirm the importance of the retractable lid and its observed intramolecular contacts in proper HDL binding and cholesterol esterification. Overall, these studies are expected to guide the design of more potent small molecule LCAT activators as well as more catalytically efficient recombinant LCAT that could be used for enzyme replacement therapy.Support or Funding InformationThis work was supported by US National Institutes of Health (NIH) grant F037815, an American Heart Association (AHA) Postdoctoral Fellowship 15POST24870001 (K.A.M.), and a University of Michigan Chemical Biology Postdoctoral Fellowship (A.G.).