686 research outputs found

    An Efficient Cross-Domain Recommendation Technique in Cold-Start Situations

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    Most of the recent studies on recommender systems are focused on single domain recommendation systems. In the single domain recommendation systems, the items that are used for training and test data set are belongs to within the same domain. Cross-site domains or item recommendations in multi-domain environment are available in Amazon i.e. it incorporate two or more domains. Few research studies are done on the cross-site recommendation systems. Cross-site recommendations provide the relationship between the two sets of items from various domains. They can provide the extra information about the users of a target domain and recommendations will be done based on that. In this paper, we will study cross-site recommendation model on the cold start situation, where the purchase history is not available for the new user. Cold-start is the well-known issue in the area of recommendation systems. It seriously affect the recommendations in the collaborative filtering approaches. In this paper, we propose a new solution to recommend products from e-commerce websites to users at social networking sites. a noteworthy issue is how to leverage knowledge from social networking websites when there is no purchase history for a customer especially in cold start situations.in particular we proposed the solution for cold start recommendation by linking the users across social networking sites and e-commerce websites i.e. customers who have social network identities and have purchased on e-commerce websites as a bridge to map user’s social networking features in to another feature representation which can be easier for product recommendation. Here we propose to learn by using recurrent neural networks both user’s and product’s feature representations called user embedding and product embedding from the data collected from e-commerce website and then apply a modified gradient boosting trees method to transform user’s social networking features in to user embedding. Once found, then develop a feature-based matrix factorization approach which can leverage the learnt user embedding for the cold-start product recommendation. Experimental results shows that our approach effectively works and gives the best recommended results in cold start situations

    Fabrication and Analysis of Amorphous Silicon TFT

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    The display technology and large area electronics got momentum with the introduction of TFT devices. TFTs can be made using different semiconducting materials or organic conducting materials as the active layer. Each one of them differ in their performance depending on the material used for the active layer. In this paper, fabrication of amorphous silicon TFT using PECVD is carried out. Simulation of the a-Si: H TFT is also carried out with the dimensions similar to that of the masks used for the fabrication. The Id-Vd plot for both the simulation and fabrication is obtained and studied

    Farmer participatory varietal selection in groundnut – A success story in Anantapur, Andhra Pradesh, India

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    Farmer participatory varietal selection trials in Anantapur, Andhra Pradesh, India identified ICGV 91114 as the most productive groundnut cultivar. This cultivar was adopted for large-scale production, giving higher pod and haulm yields and comparable shelling outturn compared with the control cultivar TMV 2

    Protein Localization with Flexible DNA or RNA

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    Localization of activity is ubiquitous in life, and also within sub-cellular compartments. Localization provides potential advantages as different proteins involved in the same cellular process may supplement each other on a fast timescale. It might also prevent proteins from being active in other regions of the cell. However localization is at odds with the spreading of unbound molecules by diffusion. We model the cost and gain for specific enzyme activity using localization strategies based on binding to sites of intermediate specificity. While such bindings in themselves decrease the activity of the protein on its target site, they may increase protein activity if stochastic motion allows the acting protein to touch both the intermediate binding site and the specific site simultaneously. We discuss this strategy in view of recent suggestions on long non-coding RNA as a facilitator of localized activity of chromatin modifiers

    Development and Application of an Indirect Competitive Enzyme-Linked Immunoassay for Aflatoxin M1 in Milk and Milk-Based Confectionery

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    High-titer rabbit polyclonal antibodies to aflatoxin M1 (AFM1) were produced by utilizing AFM1- bovine serum albumin (BSA) conjugate as an immunogen. An indirect competitive enzyme-linked immunosorbent assay was standardized for estimating AFM1 in milk and milk products. To avoid the influence of interfering substances present in the milk samples, it was necessary to prepare AFM1 standards in methanol extracts of certified reference material (CRM) not containing detectable AFM1 (<0.05 ng/g). The reliability of the procedure was assessed by using CRM with AFM1 concentrations of <0.5 and 0.76 ng/g. Also, assays of milk samples mixed with AFM1 ranging in concentration between 0.5 and 50 ng/L gave recoveries of >93%. The relative cross-reactivity with aflatoxins (AF) and ochratoxin A, assessed as the amount of AFM1 necessary to cause 50% inhibition of binding, was 5% for AFB1 and much less for AFB2, AFG1, and AFG2; there was no reaction with ochratoxin A. AFM1 contamination was measured in retail milk and milk products collected from rural and periurban areas in Andhra Pradesh, India. Of 280 milk samples tested, 146 were found to contain <0.5 ng/mL of AFM1; in 80 samples it varied from 0.6 to 15 ng/mL, in 42 samples from 16 to 30 ng/mL, and in 12 samples from 31 to 48 ng/mL. Most of the milk samples that contained high AFM1 concentrations were obtained from periurban locations. The results revealed a significant exposure of humans to AFM1 levels in India and thus highlight the need for awareness of risk among milk producers and consumers

    Alteration of Proteins and Pigments Influence the Function of Photosystem I under Iron Deficiency from Chlamydomonas reinhardtii

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    BACKGROUND: Iron is an essential micronutrient for all organisms because it is a component of enzyme cofactors that catalyze redox reactions in fundamental metabolic processes. Even though iron is abundant on earth, it is often present in the insoluble ferric [Fe (III)] state, leaving many surface environments Fe-limited. The haploid green alga Chlamydomonas reinhardtii is used as a model organism for studying eukaryotic photosynthesis. This study explores structural and functional changes in PSI-LHCI supercomplexes under Fe deficiency as the eukaryotic photosynthetic apparatus adapts to Fe deficiency. RESULTS: 77K emission spectra and sucrose density gradient data show that PSI and LHCI subunits are affected under iron deficiency conditions. The visible circular dichroism (CD) spectra associated with strongly-coupled chlorophyll dimers increases in intensity. The change in CD signals of pigments originates from the modification of interactions between pigment molecules. Evidence from sucrose gradients and non-denaturing (green) gels indicates that PSI-LHCI levels were reduced after cells were grown for 72 h in Fe-deficient medium. Ultrafast fluorescence spectroscopy suggests that red-shifted pigments in the PSI-LHCI antenna were lost during Fe stress. Further, denaturing gel electrophoresis and immunoblot analysis reveals that levels of the PSI subunits PsaC and PsaD decreased, while PsaE was completely absent after Fe stress. The light harvesting complexes were also susceptible to iron deficiency, with Lhca1 and Lhca9 showing the most dramatic decreases. These changes in the number and composition of PSI-LHCI supercomplexes may be caused by reactive oxygen species, which increase under Fe deficiency conditions. CONCLUSIONS: Fe deficiency induces rapid reduction of the levels of photosynthetic pigments due to a decrease in chlorophyll synthesis. Chlorophyll is important not only as a light-harvesting pigment, but also has a structural role, particularly in the pigment-rich LHCI subunits. The reduced level of chlorophyll molecules inhibits the formation of large PSI-LHCI supercomplexes, further decreasing the photosynthetic efficiency

    Generation of Induced Pluripotent Stem Cells from the Prairie Vole

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    The vast majority of animals mate more or less promiscuously. A few mammals, including humans, utilize more restrained mating strategies that entail a longer term affiliation with a single mating partner. Such pair bonding mating strategies have been resistant to genetic analysis because of a lack of suitable model organisms. Prairie voles are small mouse-like rodents that form enduring pair bonds in the wild as well as in the laboratory, and consequently they have been used widely to study social bonding behavior. The lack of targeted genetic approaches in this species however has restricted the study of the molecular and neural circuit basis of pair bonds. As a first step in rendering the prairie vole amenable to reverse genetics, we have generated induced pluripotent stem cell (IPSC) lines from prairie vole fibroblasts using retroviral transduction of reprogramming factors. These IPSC lines display the cellular and molecular hallmarks of IPSC cells from other organisms, including mice and humans. Moreover, the prairie vole IPSC lines have pluripotent differentiation potential since they can give rise to all three germ layers in tissue culture and in vivo. These IPSC lines can now be used to develop conditions that facilitate homologous recombination and eventually the generation of prairie voles bearing targeted genetic modifications to study the molecular and neural basis of pair bond formation
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