731 research outputs found

    Optimization of cholesterol removal, growth and fermentation patterns of Lactobacillus acidophilus ATCC 4962 in the presence of mannitol, fructo-oligosaccharide and inulin: a response surface methodology approach

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    Aims: To optimize cholesterol removal by Lactobacillus acidophilus ATCC 4962 in the presence of prebiotics, and study the growth and fermentation patterns of the prebiotics. Methods and Results: Lactobacillus acidophilus ATCC 4962 was screened in the presence of six prebiotics, namely sorbitol, mannitol, maltodextrin, hi-amylose maize, fructo-oligosaccharide (FOS) and inulin in order to determine the best combination for highest level of cholesterol removal. The first-order model showed that the combination of inoculum size, mannitol, FOS and inulin was best for removal of cholesterol. The second-order polynomial regression model estimated the optimum condition of the factors for cholesterol removal by L. acidophilus ATCC 4962 to be 2.64% w/v inoculum size, 4.13% w/v mannitol, 3.29% w/v FOS and 5.81% w/v inulin. Analyses of growth, mean doubling time and short-chain fatty acid (SCFA) production using quadratic models indicated that cholesterol removal and the production of SCFA were growth associated. Conclusions: Optimum cholesterol removal was obtained from the fermentation of L. acidophilus ATCC 4962 in the presence of mannitol, FOS and inulin. Cholesterol removal and the production of SCFA appeared to be growth associated and highly influenced by the prebiotics. Significance and Impact of the Study: Response surface methodology proved reliable in developing the model, optimizing factors and analysing interaction effects. The results provide better understanding on the interactions between probiotic and prebiotics for the removal of cholesterol

    The 5ā€²-3ā€² exoribonuclease Pacman is required for normal male fertility and is dynamically localized in cytoplasmic particles in Drosophila testis cells

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    The exoribonuclease Xrn1 is widely recognised as a key component in the 5'-3' RNA degradation pathway. This enzyme is highly conserved between yeast and humans and is known to be involved in RNA interference and degradation of microRNAs as well as RNA turnover. In yeast and human tissue culture cells, Xrn1 has been shown to be a component of P-bodies (processing bodies), dynamic cytoplasmic granules where RNA degradation can take place. In this paper we show for the first time that Pacman, the Drosophila homologue of Xrn1, is localized in cytoplasmic particles in Drosophila testis cells. These particles are present in both the mitotically dividing spermatogonia derived from primordial stem cells and in the transcriptionally active spermatocytes. Pacman is co-localized with the decapping activator dDcp1 and the helicase Me31B (a Dhh1 homologue) in these particles, although this co-localization is not completely overlapping, suggesting that there are different compartments within these granules. Particles containing Pacman respond to stress and depletion of 5'-3' decay factors in the same way as yeast P-bodies, and therefore are likely to be sites of mRNA degradation or storage. Pacman is shown to be required for normal Drosophila spermatogenesis, suggesting that control of mRNA stability is crucial in the testis differentiation pathway

    Inconsistency of QED in the Presence of Dirac Monopoles

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    A precise formulation of U(1)U(1) local gauge invariance in QED is presented, which clearly shows that the gauge coupling associated with the unphysical longitudinal photon field is non-observable and actually has an arbitrary value. We then re-examine the Dirac quantization condition and find that its derivation involves solely the unphysical longitudinal coupling. Hence an inconsistency inevitably arises in the presence of Dirac monopoles and this can be considered as a theoretical evidence against their existence. An alternative, independent proof of this conclusion is also presented.Comment: Extended and combined version, refinements added; 20 LaTex pages, Published in Z. Phys. C65, pp.175-18

    On the Quark Mass Dependence of Two Nucleon Observables

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    We study the implications of lattice QCD determinations of the S-wave nucleon-nucleon scattering lengths at unphysical light quark masses. It is found that with the help of nuclear effective field theory (NEFT), not only the quark mass dependence of the effective range parameters, but also the leading quark mass dependence of all the low energy deuteron matrix elements can be obtained. The quark mass dependence of deuteron charge radius, magnetic moment, polarizability and the deuteron photodisintegration cross section are shown based on the NPLQCD lattice calculation of the scattering lengths at 354 MeV pion mass and the NEFT power counting scheme of Beane, Kaplan and Vuorinen. Further improvement can be obtained by performing the lattice calculation at smaller quark masses. Our result can be used to constrain the time variation of isoscalar combination of u and d quark mass m_q, to help the anthropic principle study to find the m_q range which allows the existence of life, and to provide a weak test of the multiverse conjecture.Comment: 18 pages, 5 figure

    Neural Sign Reenactor: Deep Photorealistic Sign Language Retargeting

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    In this paper, we introduce a neural rendering pipeline for transferring the facial expressions, head pose, and body movements of one person in a source video to another in a target video. We apply our method to the challenging case of Sign Language videos: given a source video of a sign language user, we can faithfully transfer the performed manual (e.g., handshape, palm orientation, movement, location) and non-manual (e.g., eye gaze, facial expressions, mouth patterns, head, and body movements) signs to a target video in a photo-realistic manner. Our method can be used for Sign Language Anonymization, Sign Language Production (synthesis module), as well as for reenacting other types of full body activities (dancing, acting performance, exercising, etc.). We conduct detailed qualitative and quantitative evaluations and comparisons, which demonstrate the particularly promising and realistic results that we obtain and the advantages of our method over existing approaches.Comment: Accepted at AI4CC Workshop at CVPR 202

    Pembangunan model sistem sanitasi, perparitan dan pembentungan sebagai alat bahan bantu dalam subjek sistem sanitasi, perparitan dan pembentungan

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    Dengan perkembangan teknologi kini, salah satu pendekatan pengajaran yang baharu adalah menggunakan model. Kajian ini dijalankan untuk membangunkan satu model iaitu Model Sistem Sanitasi, Perparitan dan Pembentungan sebagai alat bahan bantu mengajar (ABBM) dalam subjek Sistem Sanitasi, Perparitan dan Pembentungan dalam kalangan guru dan pelajar dalam bidang Teknologi Pembinaan. Objektif kajian ini adalah membangunkan model Sistem Sanitasi, Perparitan dan Pembentungan yang sesuai dari segi bahan dan reka bentuk serta menguji kebolehfungsiannya sebagai ABBM bagi subjek Sistem Sanitasi, Perparitan dan Pembentungan. Data yang diperolehi dalam kajian ini pula adalah hasil analisis data yang dibuat menggunakan borang soal selidik. Analisis data dalam kajian ini secara manual dengan menggunakan kalkulator dan dipersembahkan dalam bentuk peratusan dan taburan kekerapan. Pengkaji telah memilih lima orang responden yang pakar dalam subjek Sistem Sanitasi, Perparitan dan Pembentungan untuk menjadi sampel kajian. Melalui hasil analisis data menunjukkan bahawa responden bersetuju bahawa model ini sesuai dibangunkan dan boleh digunakan sebagai ABBM dalam subjek Sistem Sanitasi, Perparitan dan Pembentunga

    Evaluation of Load Transfer in the Cellulosic-Fiber/Polymer Interphase Using a Micro-Raman Tensile Test

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    The objectives of this research were (1) to use a Raman micro-spectroscopic technique to determine the tensile stress distributions of a cellulosic-fiber/polymer droplet interphase, and (2) to examine if the stress profile could be used to evaluate load transfer in fiber/polymer adhesion. Cellulosic fibers were treated with various silanes (amino, phenylamino, phenyl, and octadecyl functionalities) and a styrene-maleic anhydride copolymer to create different interphases upon bonding with polystyrene. A single fiber, bonded with a micro-droplet of polystyrene in the mid-span region of its gage length, was strained in tension. Raman spectra were collected at five-micrometer intervals along the embedded region of the fiber. The stress-dependent peak of cellulose (895 cm-1) was analyzed for frequency shift so that the local tensile stress in the interface region could be determined. Results showed that the local tensile stresses of the strained fiber were lower in the embedded region compared to the exposed region, suggesting a transfer of load from the fiber to the matrix polymer. A deeper and sharper decline of the stress profile was observed when the fiber/droplet interaction was enhanced. Further analyses, involving conversion of tensile stress profiles to shear stress distributions in the interphase, confirmed that the micro-Raman/tensile test can be employed to evaluate fiber/matrix interfacial bonding in composites. This success signifies the possibility of evaluating adhesion between cellulosic fibers and brittle polymers, which is difficult to study using common micromechanical tests. Use of the micro-Raman technique can improve our understanding of wood/polymer adhesion

    Smooth Paths on Three Dimensional Lattice

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    A particular class of random walks with a spin factor on a three dimensional cubic lattice is studied. This three dimensional random walk model is a simple generalization of random walk for the two dimensional Ising model. All critical diffusion constants and associated critical exponents are calculated. Continuum field theories such as Klein-Gordon, Dirac and massive Chern-Simons theories are constructed near several critical points.Comment: 7 pages,NUP-A-94-
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