A study of the histozoic oyster parasite, Perkinsus marinus: I. Disease processes in American oysters (Crassostrea virginica). II. Biochemistry of Perkinsus marinus

Numerous studies have investigated the disease processes of Perkinsus marinus in the oyster, Crassostrea virginica. However, the transmission dynamics and factors affecting P. marinus infection are still unclear. The objectives of this study were to investigate: (1) the principal and most effective lifestage of P. marinus, (2) the synergistic effects of temperature, salinity and P. marinus dose on disease prevalence, (3) suppression of host reactive oxygen intermediates by P. marinus, (4) the localization of acid phosphatase in the parasite, (5) the effects of temperature and salinity on acid phosphatase secretion, and (6) the P. marinus lipid and fatty acid composition. Meronts were more infective than prezoosporangia, and infectivity was dose dependent (100 cells minimum). High temperatures, salinities and P. marinus doses increased infection prevalence and intensity. Temperature was the most important factor influencing disease susceptibility, followed by cell dosage and salinity. Both temperature and salinity significantly affected the host cellular and humoral factors in oysters. P. marinus suppression of hemocyte reactive oxygen intermediates production, as assessed by chemiluminescence was dose dependent. Zymosan stimulated hemocyte chemiluminescence was reduced, suggesting that live P. marinus cells or their extra-cellular products suppress host reactive oxygen intermediates production. Acid phosphatase activity in P. marinus cells increased with increasing temperature. Meronts had higher acid phosphatase activity than prezoosporangia. Extracellular acid phosphatase secretion by P. marinus was dose dependent, increasing with temperature and osmolality. Electron microscopy revealed that acid phosphatase activity was localized primarily in the nucleus, but was also present in the cell membrane. Lipid classes of meronts resembled those found in their media. Phospholipids were the major lipid class in meronts, while triacylglycerols were dominant in prezoosporangia isolated from infected oyster tissue. Results indicated that meronts may be capable of interconversion of lipid classes. Both meronts and prezoosporangia had much higher levels of arachidonic acid than the host

A Note on Implementing Recurrence Quantification Analysis for Network Anomaly Detection

This paper deal with the network anomaly detection, based on the analysis of non-stationary properties that occur in the aggregated IP traffic flows. We use recurrence quantification analysis (RQA), a mathematical nonlinear technique to achieve this task. The objective is to model the standard network traffic and report any deviation from it. We create a baseline from which we derive the RQA parameters. Using these parameters we explore the hidden recurrence patterns in the network traffic. Further, the detection is analysed using the support vector machine to classify the deviations from the regular traffic. Experiments are conducted on Vellore Institute of Technology University campus network traffic data to validate the model.Defence Science Journal, 2012, 62(2), pp.112-116, DOI:http://dx.doi.org/10.14429/dsj.62.117

Revolutionizing Denture Excellence: An Invigorating In-Vitro Exploration of Organic Products in Prosthetic Rehabilitation

The denture base comes into contact with diverse substances in the oral cavity, acting as a reservoir for microorganisms like corynebacterium, streptococcus, lactobacillus, and candida. This colonization elevates the risk of complications such as denture stomatitis and candidiasis. Commercial denture cleaners have explored the use of natural ingredients, less commonly employed but offering various advantages. These ingredients aim to mitigate the potential issues associated with microbial colonization on denture surfaces, contributing to improved oral hygiene for denture wearers. The exploration of natural elements reflects a nuanced approach to denture care, considering both efficacy and less conventional alternatives

Complete genome sequence of a Staphylococcus epidermidis bacteriophage isolated from the anterior nares of humans

We report here the complete genome sequence of a virulent Staphylococcus epidermidis siphophage, phage 6ec, isolated from the anterior nares of a human. This viral genome is 93,794 bp in length, with a 3' overhang cos site of 10 nucleotides, and it codes for 142 putative open reading frames

A new Adaptation in Bridgeless Interleaved Power Factor Correction design for High Efficiency

Seeking the requirements of world’s energy conversions, developments are tracked. The research and development of the AC-DC conversion circuit for variable frequency control, which is closely related to human life. It uses the bridgeless rectifier circuit, coupled with the Interleaved Boost and “PFC” (Power Factor Correction) technology to design a high-efficiency AC/DC conversion circuit, to provide a load of 400V, 2KW. The system efficiency can reach up to 96%. The power factor is close to 1, the input current ripple is below 0.8A and the output voltage ripple is below 6V. This paper presents the comparison of various current control techniques employed for a bridgeless interleaved boost converter for improving the power quality. The major control strategies discussed in this paper are: peak current, average current mode and borderline current control

Mutations that alter the regulation of the chb operon of Escherichia coli allow utilization of cellobiose

Wild-type strains of Escherichia coli are normally unable to metabolize cellobiose. However, cellobiose-positive (Cel+) mutants arise upon prolonged incubation on media containing cellobiose as the sole carbon source. We show that the Cel+ derivatives carry two classes of mutations that act concertedly to alter the regulation of the chb operon involved in the utilization of N,N'-diacetylchitobiose. These consist of mutations that abrogate negative regulation by the repressor NagC as well as single base-pair changes in the transcriptional regulator chbR that translate into single-amino-acid substitutions. Introduction of chbR from two Cel+ mutants resulted in activation of transcription from the chb promoter at a higher level in the presence of cellobiose, in reporter strains carrying disruptions of the chromosomal chbR and nagC. These transformants also showed a Cel+ phenotype on MacConkey cellobiose medium, suggesting that the wild-type permease and phospho-β-glucosidase, upon induction, could recognize, transport and cleave cellobiose respectively. This was confirmed by expressing the wild-type genes encoding the permease and phospho-β-glucosidase under a heterologous promoter. Biochemical characterization of one of the chbR mutants, chbRN238S, showed that the mutant regulator makes stronger contact with the target DNA sequence within the chb promoter and has enhanced recognition of cellobiose 6-phosphate as an inducer compared with the wild-type regulator

Antioxidant activity of Peanut (Arachis Hypogaea L.) Skin Extract: Application in Soybean and Mustard Oil

Total phenolics of peanut skin obtained by different methods were estimated; the effect of different solvents on extractability of total phenolic compounds has also been evaluated. The effect of peanut skin extract, possessing highest phenolics and DPPH radical scavenging activity, was evaluated by schaal oven test in the soybean oil, while oxidative stability of mustard oil was evaluated by Rancimat method. Total phenolics were obtained highest (76.0 ± 2.12 to 101.7 ± 5.54 mg/g GAE dw) in the roasted samples, followed by the dry samples (54.7 ± 1.78 to 89.1 ± 3.78 mg/g GAE dw), and lowest (14.5 ± 0.95 to 21.6 ± 1.02 mg/g GAE dw) in the blanched samples; 80% methanol extraction provided better extractability of phenolic compounds than the aqueous and 80% ethanol extraction method. The peroxide value and induction period of different oils was also evaluated in the present study, which clearly showed that peanut skin extract offered significantly (P < 0.05) better or at least similar protection against oxidation in the oils; than the synthetic antioxidant (BHT). Thus, peanut skin may be a good source of natural antioxidants for stabilization of various vegetable oils, during harsh processing and unavoidable storage conditions