660 research outputs found

    Sharpening up Galactic all-sky maps with complementary data - A machine learning approach

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    Galactic all-sky maps at very disparate frequencies, like in the radio and γ\gamma-ray regime, show similar morphological structures. This mutual information reflects the imprint of the various physical components of the interstellar medium. We want to use multifrequency all-sky observations to test resolution improvement and restoration of unobserved areas for maps in certain frequency ranges. For this we aim to reconstruct or predict from sets of other maps all-sky maps that, in their original form, lack a high resolution compared to other available all-sky surveys or are incomplete in their spatial coverage. Additionally, we want to investigate the commonalities and differences that the ISM components exhibit over the electromagnetic spectrum. We build an nn-dimensional representation of the joint pixel-brightness distribution of nn maps using a Gaussian mixture model and see how predictive it is: How well can one map be reproduced based on subsets of other maps? Tests with mock data show that reconstructing the map of a certain frequency from other frequency regimes works astonishingly well, predicting reliably small-scale details well below the spatial resolution of the initially learned map. Applied to the observed multifrequency data sets of the Milky Way this technique is able to improve the resolution of, e.g., the low-resolution Fermi LAT maps as well as to recover the sky from artifact-contaminated data like the ROSAT 0.855 keV map. The predicted maps generally show less imaging artifacts compared to the original ones. A comparison of predicted and original maps highlights surprising structures, imaging artifacts (fortunately not reproduced in the prediction), and features genuine to the respective frequency range that are not present at other frequency bands. We discuss limitations of this machine learning approach and ideas how to overcome them

    Use of meat juice and blood serum with a miniaturised protein microarray assay to develop a multi-parameter IgG screening test with high sample throughput potential for slaughtering pigs

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    Background Serological screening of pig herds at the abattoir is considered a potential tool to improve meat inspection procedures and herd health management. Therefore, we previously reported the feasibility of a miniaturised protein microarray as a new serological IgG screening test for zoonotic agents and production diseases in pigs. The present study investigates whether the protein microarray-based assay is applicable for high sample throughput using either blood serum or meat juice. Material and methods Microarrays with 12 different antigens were produced by Abbott (formerly Alere Technologies GmbH) Jena, Germany in a previously offered ‘ArrayTube’ platform and in an ‘ArrayStrip’ platform for large-scale use. A test protocol for the use of meat juice on both microarray platforms was developed. Agreement between serum and meat juice was analysed with 88 paired samples from three German abattoirs. Serum was diluted 1:50 and meat juice 1:2. ELISA results for all tested antigens from a preceding study were used as reference test to perform Receiver Operating Characteristic analysis for both test specimens on both microarray platforms. Results High area under curve values (AUC > 0.7) were calculated for the analysis of T. gondii (0.87), Y. enterocolitica (0.97), Mycoplasma hyopneumoniae (0.84) and Actinobacillus pleuropneumoniae (0.71) with serum as the test specimen and for T. gondii (0.99), Y. enterocolitica (0.94), PRRSV (0.88), A. pleuropneumoniae (0.78) and Salmonella spp. (0.72) with meat juice as the test specimen on the ArrayStrip platform. Cohens kappa values of 0.92 for T. gondii and 0.82 for Y. enterocolitica were obtained for the comparison between serum and meat juice. When applying the new method in two further laboratories, kappa values between 0.63 and 0.94 were achieved between the laboratories for these two pathogens. Conclusion Further development of a miniaturised pig-specific IgG protein microarray assay showed that meat juice can be used on microarray platforms. Two out of twelve tested antigens (T. gondii, Y. enterocolitica) showed high test accuracy on the ArrayTube and the ArrayStrip platform with both sample materials

    Otimização das condições de cultivo para a produção de enzimas degradadoras de fitato por Enterobacter sakazakii ASUIA279 isoladas da raiz de milho da Malásia

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    The production of extracellular phytase by Enterobacter sakazakii ASUIA279 was optimized using response surface methodology with full-factorial faced centred central composite design. Two sets of experiments were carried out to optimize the five most profound factors of the cultivation conditions in order to maximize phytase production. Incubation temperature, initial pH of the media and percentage of rice bran supplemented into the media were optimized in Erlenmeyer flasks while agitation and aeration effect were controlled in a bioreactor. This design reduced the number of actual experiment performed to optimize phytase production and allowed the study of possible interactions among the factors. In the first set of experiments linear and quadratic effect of initial pH was determined to be the most significant factor affecting phytase production. In the bioreactor both linear effects of agitation and aeration, were identified to be highly significant (> 99 %) in respect to phytase yields. Optimal phytase production was observed at a incubation temperature of 39.7 ºC, an initial pH of 7.1, supplementation with 13.6 % rice bran , 320 rpm of agitation and 0 vvm of aeration.  A produção de fitase extracelular por Enterobacter sakazakii ASUIA279 foi otimizada usando a metodologia de superfície de resposta com projeto de compósito central centralizado em face de fatorial completo. Dois conjuntos de experimentos foram realizados para otimizar os cinco fatores mais profundos das condições de cultivo, a fim de maximizar a produção de fitase. A temperatura de incubação, o pH inicial do meio e a porcentagem de farelo de arroz suplementado no meio foram otimizados em frascos de Erlenmeyer, enquanto o efeito de agitação e aeração foi controlado em um biorreator. Este projeto reduziu o número de experimentos reais realizados para otimizar a produção de fitase e permitiu o estudo de possíveis interações entre os fatores. No primeiro conjunto de experiências, o efeito linear e quadrático do pH inicial foi determinado como o fator mais significativo que afeta a produção de fitase. No biorreator, ambos os efeitos lineares da agitação e aeração foram identificados como altamente significativos (> 99%) em relação aos rendimentos da fitase. A produção ótima de fitase foi observada na temperatura de incubação de 39,7 ºC, pH inicial de 7,1, suplementação com 13,6% de farelo de arroz, 320 rpm de agitação e 0 vvm de aeração

    Production, Characterization, and Molecular Phylogenetic Analysis of Phytase from Aspergillus niger Isolates of an Indonesia Origin

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    This research aimed at analyzing the phytase from fungal isolates SB1, SB2, BS, and WF produced in cornstarch with glucose medium (CS+Glu) as carbon sources and Potatoes dextrose broth (PDB). The activity of phytase from isolates SB1, SB2, BS, and WF produced in CS+Glu medium was 2.97 UmL-1, 2.87 UmL-1, 3.18 UmL-1, and 4.37 UmL-1, respectively, while the activity of phytases was 2.07 UmL-1, 2.17 UmL-1, 2.22 UmL-1, and 2.78 UmL-1 respectively in PDB medium. The optimal temperature of SB1 and WF phytase was 40°C, while SB2 and BS were 50°C and 60°C, respectively. The optimal pH of SB1 and WF phytase was 5.0, while SB2 and BS phytase were 6.0, and 4.0 respectively. 18S rRNA gene analysis revealed that SB1 was 99% identical to Aspergillus niger ANTS (KY825168.1), SB2, BS, and WF were 99% identical to A. niger Moriga leaf (MG889596.1). Multiple sequences and phylogenetic analysis of phytase gene showed that phyA_SB1 and phyA_SB2 were 98% homology with A. ficuum (AAB26466), 97% with A. niger (ADP05107) while phyA_WF was 99% with A. ochraceoroseus (PLB29348), 98% with A. niger (ADP05105). The deduced proteins contain conserved motifs RHGARYPTD at N-terminal while lacking HD motif at C-terminal. These phytases were in the same cluster with Aspergillus sp. phytase A indicating that they belong to Histidine Acid Phosphatases (HAP) family

    BIOCHEMICAL CHARACTERIZATION OF RECOMBINANT PHYTASE ENZYME (phyK) FROM Klebsiella sp. ASR1 ENCAPSULATED WITH ALGINATE

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    Karakterisasi Biokimia Enzim Fitase Rekombinan (phyK) dari Klebsiella sp. ASR1 Yang Dienkapsulasi Dengan AlginatEnzim fitase melepas molekul fosfor pada atom C dari benzena Inositol fitat. Tetapi fitase memiliki kelemahan tidak mampu bertahan terhadap kondisi ekstrim dalam lambung nonruminansia. Solusi dalam penelitian ini yaitu fitase dienkapsulasi menggunakan alginat. Penelitian ini bertujuan mengkarakterisasi fitase setelah dienkapsulasi menggunakan alginate. Hasil penelitian ini yaitu fitase yang dienkapsulasi memiliki aktivitas tertinggi pada pH 6,0, sedangkan fitase tanpa enkapsulasi pada pH 5,0. Suhu optimum untuk aktivitas tertinggi fitase yang dienkapsulasi yaitu 70ºC, sedangkan fitase tanpa enkapsulasi 37ºC. Untuk perlakuan penambahan ion logam, aktivitas tertinggi fitase yang dienkapsulasi terjadi dengan penambahan 0,1 mM Fe2+ dan 1,0 mM Ca2+, sedangkan fitase tanpa enkapsulasi dengan penambahan 0,1 mM Fe2+. Berdasarkan hasil penelitian ini, fitase yang dienkapsulasi memiliki keunggulan lebih banyak dibandingkan dengan fitase tanpa enkapsulasi, karena mampu bertahan pada pH dan suhu tinggi, dan beberapa efek ion logam.Kata Kunci: alginat, asam fitat, enkapsulasi, fitase, fitase rekombinanABSTRACTPhytase enzymes release phosphorus molecules on the C atom from benzene inositol phytate. But phytase has the disadvantage of being unable to withstand extreme conditions in the non-ruminant stomach. The solution in this research was phytase encapsulated using alginate. This study aims to characterize phytase after being encapsulated using alginate. The results of this study were the encapsulated phytase had the highest activity at pH 6.0, while the unencapsulated phytase at pH 5.0. The optimum temperature for the highest activity of the encapsulated phytase was 70ºC, while the unencapsulated phytase 37ºC. For treatment of metal ion addition, the highest activity of the encapsulated phytase occurred with the addition of 0.1 mM Fe2+ and 1.0 mM Ca2+, while the unencapsulated phytase with the addition of 0.1 mM Fe2+. Based on the results of this study, the encapsulated phytase had more advantages compared to the unencapsulated phytase, as the former withstand high pH and temperature, and some metal ion effects

    Effect of Traditional Household Processes on Iron, Zinc and Copper Bioaccessibility in Black Bean (Phaseolus vulgaris L.)

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    Micronutrient deficiencies are a major public health problem. Beans are an important plant-based source of iron, zinc and copper, but their absorption is reduced in the presence of anti-nutrients such as phytates, polyphenols and tannins. Soaking and discarding the soaking water before cooking is unanimously recommended, but this can result in mineral loss. Data on the consequences for mineral bioaccessibility is still limited. This study aimed to evaluate iron, zinc and copper bioaccessibility in black beans cooked (regular pan, pressure cooker) with and without the soaking water. For that, three batches of black beans were investigated in triplicate, each split in nine parts (raw grains and four different household processes in duplicate) and analyzed by applying the quarter technique, resulting in a grand total of 164 samples. Minerals were quantified by ICP-MS (inductively coupled plasma mass spectrometry), myo-inositol phosphates (InsP5, InsP6) by HPLC (high-performance liquid chromatography) ion-pair chromatography, total polyphenols using Folin-Denis reagent and condensed tannins using Vanillin assay. Mineral bioaccessibility was determined by in vitro digestion and dialysis. All treatments resulted in a statistically significant reduction of total polyphenols (30%) and condensed tannins (20%). Only when discarding the soaking water a loss of iron (6%) and copper (30%) was observed, and InsP6 was slightly decreased (7%) in one treatment. The bioaccessibility of iron and zinc were low (about 0.2% iron and 35% zinc), but copper presented high bioaccessibility (about 70%). Cooking beans under pressure without discarding the soaking water resulted in the highest bioaccessibility levels among all household procedures. Discarding the soaking water before cooking did not improve the nutritional quality of the beans

    Effects of phytase-supplemented fermentation and household processing on the nutritional quality of Lathyrus sativus L. seeds

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    Grass pea (Lathyrus sativus L.) is commonly consumed in cooked, fermented, and roasted forms in Ethiopia. However, the impacts of household processing practices on its nutrients, antinutrients, and toxic compounds have not been adequately studied. Therefore, the effects of household processing and fermentation in the presence and absence of a phytase on the contents of β-N-oxalyl-L-α,β-diaminopropionic acid (β-ODAP), myo-inositol phosphates, crude protein, minerals and the in vitro bioaccessibility were investigated. Fermentation exhibited a significant decline in β-ODAP (13.0–62.0%) and phytate (7.3–90.5%) irrespective of the presence of phytase. Pressure and pan cooking after discarding the soaking water resulted in a 27.0 and 16.2% reduction in β-ODAP. A 30% reduction in phytate was observed during germination followed by roasting. In addition, germination resulted in a significant (p < 0.05) increase in crude protein. Germination and germination followed by roasting resulted in the highest Fe bioaccessibilities (more than 25 fold higher compared to untreated samples) followed by pressure cooking and soaking. Processing also improved Zn bioaccessibilities by 50.0% (soaked seed without soaking water), 22.5% (soaked seed with soaking water), and 4.3% (germination). Thus, the processing technologies applied were capable of reducing the content of phytate (InsP6) and β-ODAP with a concomitant increase in mineral bioaccessibilities. Processing of grass peas could therefore contribute to their more widespread utilization
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