Scale-Adaptive Group Optimization for Social Activity Planning

Studies have shown that each person is more inclined to enjoy a group activity when 1) she is interested in the activity, and 2) many friends with the same interest join it as well. Nevertheless, even with the interest and social tightness information available in online social networks, nowadays many social group activities still need to be coordinated manually. In this paper, therefore, we first formulate a new problem, named Participant Selection for Group Activity (PSGA), to decide the group size and select proper participants so that the sum of personal interests and social tightness of the participants in the group is maximized, while the activity cost is also carefully examined. To solve the problem, we design a new randomized algorithm, named Budget-Aware Randomized Group Selection (BARGS), to optimally allocate the computation budgets for effective selection of the group size and participants, and we prove that BARGS can acquire the solution with a guaranteed performance bound. The proposed algorithm was implemented in Facebook, and experimental results demonstrate that social groups generated by the proposed algorithm significantly outperform the baseline solutions.Comment: 20 pages. arXiv admin note: substantial text overlap with arXiv:1305.150

When Social Influence Meets Item Inference

Research issues and data mining techniques for product recommendation and viral marketing have been widely studied. Existing works on seed selection in social networks do not take into account the effect of product recommendations in e-commerce stores. In this paper, we investigate the seed selection problem for viral marketing that considers both effects of social influence and item inference (for product recommendation). We develop a new model, Social Item Graph (SIG), that captures both effects in form of hyperedges. Accordingly, we formulate a seed selection problem, called Social Item Maximization Problem (SIMP), and prove the hardness of SIMP. We design an efficient algorithm with performance guarantee, called Hyperedge-Aware Greedy (HAG), for SIMP and develop a new index structure, called SIG-index, to accelerate the computation of diffusion process in HAG. Moreover, to construct realistic SIG models for SIMP, we develop a statistical inference based framework to learn the weights of hyperedges from data. Finally, we perform a comprehensive evaluation on our proposals with various baselines. Experimental result validates our ideas and demonstrates the effectiveness and efficiency of the proposed model and algorithms over baselines.Comment: 12 page

(E)-N′-[1-(4-Bromo­phen­yl)ethyl­idene]benzohydrazide

The asymmetric unit of the title compound, C15H13BrN2O, contains two independent mol­ecules with different conformations; the two aromatic rings form dihedral angles of 32.4 (4) and 27.5 (4)° in the two mol­ecules. In the crystal structure, inter­molecular N—H⋯O hydrogen bonds link mol­ecules into chains propagating in [100]

Evaluation of traumatic retinopathy with ultra-wide field imaging under corneal scar or fixed small pupil

AIM: To evaluate the value of ultra-wide field (UWF) imaging in the management of traumatic retinopathy under the condition of corneal scar or fixed small pupil after complicated ocular trauma. METHODS: Twenty-eight patients (28 eyes) with complicated ocular trauma were enrolled in the study from June 2016 to May 2017, including 19 males and 9 females with age ranged from 11 to 64 (43.42±12.62)y. All patients were treated with secondary vitrectomy after emergency operation for wound repair of open ocular trauma. Direct ophthalmoscopy and 45-degree fundus photography were taken at each time point of follow up for comparison of findings with UWF images. Routine eye examination including visual acuity, intraocular pressure, slit lamp examination were performed and analyzed as well. RESULTS: Among the 28 traumatized eyes, the positive rate for identification of traumatic retinopathed was 32.1% (9 cases), 14.9% (5 cases), and 85.7% (24 cases) with direct ophthalmoscopy, 45-degree fundus photography, and UWF imaging, respectively. The detective rate of UWF imaging under the condition of corneal scar or fixed small pupil was statistically greater than that of 45-degree fundus photography and direct ophthalmoscopy (Bonferroni correction, P<0.001). UWF image was obtained in 19 eyes with opaque corneal scar, otherwise their fundus could not be seen by conventional methods. The additional findings of traumatic retinopathies by UWF imaging included periretinal membranes or pre-retinal proliferating strip, retinal holes, hemorrhage in the vitreous or sub-retinal space. CONCLUSION: UWF imaging is superior to traditional fundus photography in the evaluation of traumatic retinopathies under the condition of corneal scar or fixed small pupil after complicated ocular trauma

Effects of two Lactobacillus strains on lipid metabolism and intestinal microflora in rats fed a high-cholesterol diet

<p>Abstract</p> <p>Background</p> <p>The hypocholesterolemic effects of lactic acid bacteria (LAB) have now become an area of great interest and controversy for many scientists. In this study, we evaluated the effects of <it>Lactobacillus plantarum </it>9-41-A and <it>Lactobacillus fermentum </it>M1-16 on body weight, lipid metabolism and intestinal microflora of rats fed a high-cholesterol diet.</p> <p>Methods</p> <p>Forty rats were assigned to four groups and fed either a normal or a high-cholesterol diet. The LAB-treated groups received the high-cholesterol diet supplemented with <it>Lactobacillus plantarum </it>9-41-A or <it>Lactobacillus fermentum </it>M1-16. The rats were sacrificed after a 6-week feeding period. Body weights, visceral organ and fat pad weights, serum and liver cholesterol and lipid levels, and fecal cholesterol and bile acid concentrations were measured. Liver lipid deposition and adipocyte size were evaluated histologically.</p> <p>Results</p> <p>Compared with rats fed a high-cholesterol diet but without LAB supplementation, serum total cholesterol, low-density lipoprotein cholesterol and triglycerides levels were significantly decreased in LAB-treated rats (p < 0.05), with no significant change in high-density lipoprotein cholesterol levels. Hepatic cholesterol and triglyceride levels and liver lipid deposition were significantly decreased in the LAB-treated groups (p < 0.05). Accordingly, both fecal cholesterol and bile acids levels were significantly increased after LAB administration (p < 0.05). Intestinal <it>Lactobacillus </it>and <it>Bifidobacterium </it>colonies were increased while <it>Escherichia coli </it>colonies were decreased in the LAB-treated groups. Fecal water content was higher in the LAB-treated groups. Compared with rats fed a high-cholesterol diet, administration of <it>Lactobacillus plantarum </it>9-41-A resulted in decreases in the body weight gain, liver and fat pad weight, and adipocytes size (p < 0.05).</p> <p>Conclusions</p> <p>This study suggests that LAB supplementation has hypocholesterolemic effects in rats fed a high-cholesterol diet. The ability to lower serum cholesterol varies among LAB strains. Our strains might be able to improve the intestinal microbial balance and potentially improve intestinal transit time. Although the mechanism is largely unknown, <it>L. plantarum </it>9-41-A may play a role in fat metabolism.</p