Searching for Bayesian Network Structures in the Space of Restricted Acyclic Partially Directed Graphs

Although many algorithms have been designed to construct Bayesian network structures using different approaches and principles, they all employ only two methods: those based on independence criteria, and those based on a scoring function and a search procedure (although some methods combine the two). Within the score+search paradigm, the dominant approach uses local search methods in the space of directed acyclic graphs (DAGs), where the usual choices for defining the elementary modifications (local changes) that can be applied are arc addition, arc deletion, and arc reversal. In this paper, we propose a new local search method that uses a different search space, and which takes account of the concept of equivalence between network structures: restricted acyclic partially directed graphs (RPDAGs). In this way, the number of different configurations of the search space is reduced, thus improving efficiency. Moreover, although the final result must necessarily be a local optimum given the nature of the search method, the topology of the new search space, which avoids making early decisions about the directions of the arcs, may help to find better local optima than those obtained by searching in the DAG space. Detailed results of the evaluation of the proposed search method on several test problems, including the well-known Alarm Monitoring System, are also presented

Citric Acid and Microbial Phytase Inclusion in the Diet to Improve Utilization Phytate Phosporus and Growth of Broiler

Penelitian ini menggunakan anak ayam umur 3 sampai dengan 38 hari (180 ekor) dan 7 sampai dengan 42 hari (180 ekor). Ayam diberi ransum A, B, dan C yang berbahan dasar jagung (CSM) dan ransum E, F, dan G yang berbahan dasar gandum (WSM) yang diberi perlakuan penambahan steam pada suhu 1000C selama 10 menit. Semua ransum ditambah enzim fitase (SP-1002 ct) sebanyak 500 U/kg dan dibuat dalam bentuk pelet. Khusus ransum C dan G ditambah asam sitrat. Kandungan fosfor total ransum adalah 4,5 g/kg dan fosfor tersedia adalah 1,5 g/kg (defisien P). Bobot badan harian adalah 36, 34, dan 45 g/hari untuk ayam yang diberi ransum A, B, dan C dan 54, 46, dan 55 g/hari untuk ransum E, F, dan G. Deposisi fosfor total adalah 5,75; 5,36; dan 6,99 g berturut-turut untuk ransum A, B dan C dan 8,15; 6,90; dan 7,77 g untuk E, F, dan G. Penambahan asam sitrat dalam ransum CSM yang mengandung enzim fitase rendah mampu meningkatkan pertumbuhan dan deposisi fosfor. Pada ransum WSM, perlakuan panas menyebabkan penurunan aktifitas fitase dan penurunan ini tidak dapat digantikan dengan penambahan enzim fitase (microbial phytase) akan tetapi dapat digantikan dengan penambahan asam sitrat. Hasil penelitian ini dapat disimpulkan bahwa asam sitrat berpengaruh terhadap efisiensi enzim fitase (microbial phytase) dalam mendegradasi senyawa fitat di dalam saluran pencernaan

A multi-layered Bayesian network model for structured document retrieval

New standards in document representation, like for example SGML, XML, and MPEG-7, compel Information Retrieval to design and implement models and tools to index, retrieve and present documents according to the given document structure. The paper presents the design of an Information Retrieval system for multimedia structured documents, like for example journal articles, e-books, and MPEG-7 videos. The system is based on Bayesian Networks, since this class of mathematical models enable to represent and quantify the relations between the structural components of the document. Some preliminary results on the system implementation are also presented

Potential of Lactic Acid Bacteria Isolated From Dangke and Indonesian Beef as Hypocholesterolaemic Agent

Lactobacillus fermentum strains were successfully isolated from dangke which was a fresh cheese-like product originating from Enrekang, South Sulawesi Province, Indonesia. In addition, Lactobacillus plantarum and Lactobacillus acidophillus were isolated from beef. This study aimed to investigate the ability of those 8 LAB strains from dangke and beef in lowering cholesterol level by using in vitro study. Strain of Lactic acid bacteria used were L. fermentum strains (A323L, B111K, B323K, C113L, C212L), L. plantarum strains (IIA-1A5 and IIA-2C12), and L. acidophillus IIA-2B4. Variables observed were identification of Bile Salt Hydrolase (BSH) gene by Polymerase Chain Reaction (PCR), BSH activity and cholesterol assimilation. Phylogenetic tree indicated homology of L. plantarum IIA-IA5 was 98% to BSH gene of L. plantarum Lp529 with access code of FJ439771 and FJ439775 obtained from GenBank. The results demonstrated that eight strains of LAB isolated from dangke and beef that potentially showed cholesterol-lowering effects were L. fermentum B111K and L. plantarum IIA-1A5. L. fermentum B111K was able to assimilate cholesterol by 4.10% with assimilated cholesterol of 0.13 mg in 1010 cells. In addition, L. plantarum IIA-1A5 had BSH gene and BSH activity, as well as the ability to assimilate cholesterol by 8.10% with assimilated cholesterol of 0.06 mg in 1010 cells. It is concluded that L. fermentum B111K and L. plantarum IIA-1A5 were strains that showed cholesterol-lowering effects

Docosahexaenoic acid (DHA) promotes immunogenic apoptosis in human multiple myeloma cells, induces autophagy and inhibits STAT3 in both tumor and dendritic cells

Docosahexaenoic acid (DHA), a ω-3 polyunsaturated fatty acid found in fish oil, is a multi-target agent and exerts anti-inflammatory and anticancer activities alone or in combination with chemotherapies. Combinatorial anticancer therapies, which induce immunogenic apoptosis, autophagy and STAT3 inhibition have been proposed for long-term therapeutic success. Here, we found that DHA promoted immunogenic apoptosis in multiple myeloma (MM) cells, with no toxicity on PBMCs and DCs. Immunogenic apoptosis was shown by the emission of specific DAMPs (CRT, HSP90, HMGB1) by apoptotic MM cells and the activation of their pro-apoptotic autophagy. Moreover, immunogenic apoptosis was directly shown by the activation of DCs by DHA-induced apoptotic MM cells. Furthermore, we provided the first evidence that DHA activated autophagy in PBMCs and DCs, thus potentially acting as immune stimulator and enhancing processing and presentation of tumor antigens by DCs. Finally, we found that DHA inhibited STAT3 in MM cells. STAT3 pathway, essential for MM survival, contributed to cancer cell apoptosis by DHA. We also found that DHA inhibited STAT3 in blood immune cells and counteracted STAT3 activation by tumor cell-released factors in PBMCs and DCs, suggesting the potential enhancement of the anti-tumor function of multiple immune cells and, in particular, that of DCs

Examination of Acid-Fast Bacilli in Sputum Using Modified Light Microscope with Homemade Light Emitting Diode Additional Attachment

Typical clinical symptoms and chest X-ray is a marker of Tuberculosis (TB) sufferers. However, the diagnosis of TB in adults should be supported by microscopic examination. Currently, Bacilli microscopic examination of acid-fast bacilli (AFB) in sputum by Ziehl-Neelsen (ZN) coloring is the most widely used. However, for reasons of convenience, especially for laboratories with a considerable amount of smear samples, and due to higher sensitivity compared with ZN staining, the World Health Organization (WHO) has recommended the use of auramine-O-staining (fluorochrome  staining), which is visualized by light emitting diode (LED) fluorescence microscopy. The aim of this study was to evaluate the performance of modified light microscope with homemade LED additional attachment for examination of AFB in sputum using auramine-O-staining method. We compared the sensitivity and specificity of 2 kinds of AFB in sputum methods: ZN and fluorochrome, using culture on Lowenstein-Jensen media as the gold standard. The results showed auramine-O-staining gives more proportion of positive findings (81%) compared to the ZN method (70%). These results demonstrated that the sensitivity of auramine-O-staining was higher than ZN, however it gives more potential false positive results than ZN. The sensitivity of auramine-O-staining in detecting AFB in sputum was 100% while the specificity was 88%

Ranking structured documents using utility theory in the Bayesian network retrieval model

In this paper a new method based on Utility and Decision theory is presented to deal with structured documents. The aim of the application of these methodologies is to refine a first ranking of structural units, generated by means of an Information Retrieval Model based on Bayesian Networks. Units are newly arranged in the new ranking by combining their posterior probabilities, obtained in the first stage, with the expected utility of retrieving them. The experimental work has been developed using the Shakespeare structured collection and the results show an improvement of the effectiveness of this new approach