41 research outputs found

    Aplikasi Pengenalan Wajah Menggunakan Algoritma Backpropagation dan Voila Jones

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    Saat ini, teknologi sistem keamanan semakin berkembang pesat. Para ilmuan dibidang teknologi terus-menerus membuat ataupun menemukan cara baru untuk berupaya meningkatkan sistem keamanan pada komputer, terutama sistem keamanan dengan menggunakan metode-metode dari visi komputer seperti identifikasi ataupun berbentuk pengenalan suatu benda. Dengan perkembangan teknologi sekarang ini terutama dibidang visi komputer diharapkan mampu untuk menjawab seluruh tantangan dari sistem keamanan. Salah satu sistem keamanan dari visi komputer yang paling popular adalah sistem identifikasi atau pengenalan suatu objek atau gambar dengan menggunakan algoritma tertentu. Oleh karena itu, pada penelitian menerapkan sistem pengenalan wajah menggunakan algoritma backpropagation. Dimana, sebuah foto wajah seseorang akan dikenali berdasarkan jarak antar fitur-fitur wajah seperti: mata,hidung, dan mulut kemudian hasil dari temuan jarak fitur tersebut akan menjadi input layer pada algoritma backpropagation kemudian dengan memasukkan target output akan memunculkan idetitas pada foto atau gambar tersebut. Dari hasil pegujian 10 gambar yang dilakukan, 8 gambar berhasil dikenali 2 gambar tidak berhasil, maka tingkat akurasi aplikasi tersebur adalah 80

    Listeria monocytogenes in Milk Products

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    peer-reviewedMilk and milk products are frequently identified as vectors for transmission of Listeria monocytogenes. Milk can be contaminated at farm level either by indirect external contamination from the farm environment or less frequently by direct contamination of the milk from infection in the animal. Pasteurisation of milk will kill L. monocytogenes, but post-pasteurisation contamination, consumption of unpasteurised milk and manufacture of unpasteurised milk products can lead to milk being the cause of outbreaks of listeriosis. Therefore, there is a concern that L. monocytogenes in milk could lead to a public health risk. To protect against this risk, there is a need for awareness surrounding the issues, hygienic practices to reduce the risk and adequate sampling and analysis to verify that the risk is controlled. This review will highlight the issues surrounding L. monocytogenes in milk and milk products, including possible control measures. It will therefore create awareness about L. monocytogenes, contributing to protection of public health

    Flow Cytometry for Rapid Detection of Salmonella spp. in Seed Sprouts

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    Leakage Prediction in Mechanical Seals Under Hydrostatic Operating Condition

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    ABSTRACT This paper considers leakage in mechanical seals under hydrostatic operating condition. A contact model based on the Greenwood and Williamson contact of rough surfaces is developed for treating problems involving mechanical seals in which both the micron scale roughness of the seal face and its macro scale profile are used to obtain either a closed-form equation or a nonlinear equation relating mean plane separation to the mass flow rate. The equations involve the micron scale geometry of the rough surfaces and physical parameter of the seal and carriage. Under hydrostatic condition, it is shown that there is an approximate closed-form solution in which mass flow rate in terms of the mean plane separation, or alternatively, the mean plane separation in terms of the leakage mass flow rate is found. Equations pertaining to leakage in nominally flat seal macro profile is considered and closed form equation relating to leakage flow rate to pressure difference is obtained that contain macro and micron geometries of the seal. INTRODUCTION Mechanical seals are among important machine components and play a critical load when containment of lubricant is necessary in machinery. There is extensive literature In this paper we develop approximate equations relating contact force and mean plane separation. Using the closedform equations, we consider the leakage in flat face mechanical seals and obtain the closed form equations relating leakage mass flow rate as a function of surface topography, fluid pressure and macro geometry of a seal

    Optimization of Reverse Transcriptase PCR To Detect Viable Shiga-Toxin-Producing Escherichia coli

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    The ability of reverse transcriptase PCR (RT-PCR) to detect viable Shiga-toxin-producing Escherichia coli (STEC) was investigated. Four primer sets, each targeting a specific region in the slt-II operon, were evaluated for their stringency and specificity for slt-II mRNA. STEC were evaluated for toxin expression under various conditions, including cell growth phase, growth medium, incubation temperature, and aeration. Following primer optimization, STEC were inoculated into Trypticase soy broth and cooked ground beef enrichments. Cells were harvested and RNA or DNA was extracted at 4, 8, 12, and 24 h. RT-PCR or PCR was conducted, and the products were visualized by gel electrophoresis and by Southern blots. mRNA targets were detected in 12-h cooked ground meat enrichments with an initial inoculum of 1 CFU/g. These results indicate that RT-PCR of E. coli slt-II mRNA is useful for detection of viable STEC in ground beef

    Conservation of Genomic Localization and Sequence Content of Sau3AI-Like Restriction-Modification Gene Cassettes among Listeria monocytogenes Epidemic Clone I and Selected Strains of Serotype 1/2aâ–¿

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    Listeria monocytogenes is a food-borne pathogen with a clonal population structure and apparently limited gene flow between strains of different lineages. Strains of epidemic clone I (ECI) have been responsible for numerous outbreaks and invariably have DNA that is resistant to digestion by Sau3AI, suggesting methylation of cytosine at GATC sites. A putative restriction-modification (RM) gene cassette has been identified in the genome of the ECI strain F2365 and all other tested ECI strains but is absent from other strains of the same serotype (4b). Homologous RM cassettes have not been reported among L. monocytogenes isolates of other serotypes. Furthermore, conclusive evidence for the involvement of this RM cassette in the Sau3AI resistance phenotype of ECI strains has been lacking. In this study, we describe a highly conserved RM cassette in certain strains of serotypes 1/2a and 4a that have Sau3AI-resistant DNA. In these strains the RM cassette was in the same genomic location as in the ECI reference strain F2365. The cassette included a gene encoding a putative recombinase, suggesting insertion via site-specific recombination. Deletion of the RM cassette in the ECI strain F2365 and the serotype 1/2a strain A7 rendered the DNA of both strains susceptible to Sau3AI digestion, providing conclusive evidence that the cassette includes a gene required for methylation of cytosine at GATC sites in both strains. The findings suggest that, in addition to its presence in ECI strains, this RM cassette and the accompanying genomic DNA methylation is also encountered among selected strains of other lineages

    Validation of a Green Fluorescent Protein-Labeled Strain of Vibrio vulnificus for Use in the Evaluation of Postharvest Strategies for Handling of Raw Oysters

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    In this paper we describe a biological indicator which can be used to study the behavior of Vibrio vulnificus, an important molluscan shellfish-associated human pathogen. A V. vulnificus ATCC 27562 derivative that expresses green fluorescent protein (GFP) and kanamycin resistance was constructed using conjugation. Strain validation was performed by comparing the GFP-expressing strain (Vv-GFP) and the wild-type strain (Vv-WT) with respect to growth characteristics, heat tolerance (45°C), freeze-thaw tolerance (−20(o) and −80°C), acid tolerance (pH 5.0, 4.0, and 3.5), cold storage tolerance (5°C), cold adaptation (15°C), and response to starvation. Levels of recovery were evaluated using nonselective medium (tryptic soy agar containing 2% NaCl) with and without sodium pyruvate. The indicator strain was subsequently used to evaluate the survival of V. vulnificus in oysters exposed to organic acids (citric and acetic acids) and various cooling regimens. In most cases, Vv-GFP was comparable to Vv-WT with respect to growth and survival upon exposure to various biological stressors; when differences between the GFP-expressing and parent strains occurred, they usually disappeared when sodium pyruvate was added to media. When V. vulnificus was inoculated into shellstock oysters, the counts dropped 2 log(10) after 11 to 12 days of refrigerated storage, regardless of the way in which the oysters were initially cooled. Steeper population declines after 12 days of refrigerated storage were observed for both iced and refrigerated products than for slowly cooled product and product held under conservative harvest conditions. By the end of the refrigeration storage study (22 days), the counts of Vv-GFP in iced and refrigerated oysters had reached the limit of detection (10(2) CFU/oyster), but slowly cooled oysters and oysters stored under conservative harvest conditions still contained approximately 10(3) and >10(4) CFU V. vulnificus/oyster by day 22, respectively. The Vv-GFP levels in the oyster meat remained stable for up to 24 h when the meat was exposed to acidic conditions at various pH values. Ease of detection and comparability to the wild-type parent make Vv-GFP a good candidate for use in studying the behavior of V. vulnificus upon exposure to sublethal stressors that might be encountered during postharvest handling of molluscan shellfish

    Seeds of Zizyphus lotus: In Vivo Healing Properties of the Vegetable Oil

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    The present study has been undertaken in order to highlight the healing effect of Zizyphus lotus vegetable oil. The seeds of this plant contain an oil rate of 30%. The obtained results on the main elements composing the vegetable oil have shown that Zizyphus lotus vegetable oil has a low value of acidity index and it presents a not negligible degree of unsaturation. The value of the peroxide index of Zizyphus lotus vegetable oil is less than 10 which characterizes the most of conventional oils. Furthermore, the spectral analysis by gas chromatography has shown the presence of 53 majority and minority molecules. Thus, the evaluation of the healing activity of Z. lotus seed vegetable oil has demonstrated a highly significant effect against the negative control and silver sulfadiazine was used as conventional treatment for burns. Based on the obtained results, we can suggest that the oil extracted from the seeds of the studied plant could be used to cure wounds
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