An Entity-Association-Based Matrix Factorization Recommendation Algorithm

Collaborative filtering is the most popular approach when building recommender systems,but the large scale and sparse data of the user-item matrix seriously affect the recommendation results.Recent research shows the user’s social relations information can improve the quality of recommendation.However,most of the current social recommendation algorithms only consider the user's direct social relations,while ignoring potential users’interest preference and group clustering information.Moreover,project attribute is also important in item rating.We propose a recommendation algorithm which using matrix factorization technology to fuse user information and project information together.We first detect the community structure using overlapping community discovery algorithm,and mine the clustering information of user interest preference by a fuzzy clustering algorithm based on the project category information.On the other hand,we use project-category attribution matrix and user-project score matrix to get project comprehensive similarity and compute project feature matrix based on Entity Relation Decomposition.Fusing the user clustering information and project information together,we get Entity-Association-based Matrix Factorization(EAMF)model which can be used to predict user ratings.The proposed algorithm is compared with other algorithms on the Yelp dataset.Experimental studies show that the proposed algorithm leads to a substantial increase in recommendation accuracy on Yelp data set.

Genome-wide identification and analysis of monolignol biosynthesis genes in Salix matsudana Koidz and their relationship to accelerated growth

Lignin plays an important role in plant growth and development.It serves as a raw material for the manufacture of paper,animal feed,and chemical fertilizers.However,the regulation of lignin biosynthesis genes and the composition of the relevant gene families remain unclear in many plant species.Here,we identified and characterized 11 families of monolignol biosynthesis genes in Salix matsudana Koidz.Based on phylogenetic analysis of lignin biosynthesis genes from nine angiosperm species(Arabidopsis thaliana,Oryza sativa,Zea mays,Solanum lycopersicum,S.suchowensis,S.purpurea,Populus euphratica,P.trichocarpa,and S.matsudana),the 11 gene families could be divided into two classes that differed in their apparent evolutionary history.We compared the distribution of lignin biosynthesis genes between the two sub-genomes(At and Bt)of S.matsudana and found that more duplicated genes were present in the Bt sub-genome.We analyzed RNA sequencing data from two parents of contrasting height and two of their F1 progeny,and detected 23 differentially expressed genes(DEGs)that may regulate accelerated growth.We analyzed the promoter regions of the lignin-related DEGs and identified several hormone-related(auxin,ethylene,and cytokinin)transcription factor binding sites.These results provide an important foundation for future studies on the molecular mechanisms and genetic regulation of lignin biosynthesis and its relationship to accelerated growth in forest trees.

Use of electrosense in the feeding behavior of sturgeons

The electro-receptive lateral line system appeared early in the evolutionary history of fish.Sturgeons,members of the primitive Chondrostei group,are known for their electroreceptors(ampullae of Lorenzini)on the head,which are thought to be sensitive to weak electric fields in aquatic environments and involved in feeding,mating and migration.Here,we report the results of a set of behavioral and electrophysiological experiments designed to determine the function and characteristics of the electrosense in cultured sturgeons.The results showed Sibe-rian sturgeon(Acipenser baerii Brandt,1869)feeding striking at bio-electric fields produced by living feed-fish enclosed in a gel chamber and at the corrosion field produced by metal rods.With an electric stimulus that mim-ics the bio-electric fields produced by living prey,the relative discharge rate of electrosensory neurons in the dorsal octavolateralis nucleus(DON)was modulated by and phase-locked to sinusoidal stimulus and some units showed selectivity for dipolar direction in white sturgeon(Acipenser transmontanus Richardson,1836).This is the first study to provide the empirical evidence correlating with electrosensory behaviors and electrophysiolog-ical responses in cultured sturgeons,and suggesting that electrosense does play an innate role in feeding behav-ior of sturgeon.We believe this will have important implications for protecting sturgeons in the wild.

Sound production in marbled rockfish (Sebastiscus marmoratus) and implications for fisheries

Recently,several rockfish species(genus Sebastes)have been reported to be soniferous.To determine whether an additional rockfish species produces sounds,passive acoustic recordings were analyzed from captive marbled rockfish(Sebastiscus marmoratus)during the non-spawning season.Three distinct sounds were identified based on frequency features.The common characteristics among all sounds were low frequency(below 300 Hz)and rapidly dampened pulses consisting of 3–5 acoustic energy cycles.During free-swimming conditions in the canvas tank,the fish produced voluntary sounds with lower frequencies than the disturbance sounds produced by individuals during prodding.Two types of sounds were identified in the disturbance context:one type consists of single or double pulses with two peak frequencies,and another type consists of a series of pulses with a single peak frequency.These results suggest that specific-species and behavior-associated sounds are potentially useful in passive acoustical surveys to monitor rockfish populations and distributions remotely.