PHL 6625: A Minor Merger-Associated QSO Behind NGC 247

PHL 6625 is a luminous quasi-stellar object (QSO) at z = 0.3954 located behind the nearby galaxy NGC 247 (z = 0.0005). Hubble Space Telescope (HST) observations revealed an arc structure associated with it. We report on spectroscopic observations with the Very Large Telescope (VLT) and multiwavelength observations from the radio to the X-ray band for the system, suggesting that PHL 6625 and the arc are a close pair of merging galaxies, instead of a strong gravitational lens system. The QSO host galaxy is estimated to be (4-28) x 10^10 M_sun, and the mass of the companion galaxy of is estimated to be M_* = (6.8 +/- 2.4) x 10^9 M_sun, suggesting that this is a minor merger system. The QSO displays typical broad emission lines, from which a black hole mass of about (2-5) x 10^8 M_sun and an Eddington ratio of about 0.01-0.05 can be inferred. The system represents an interesting and rare case where a QSO is associated with an ongoing minor merger, analogous to Arp 142.Comment: ApJ to appea

Empirical Research on the Impact of Personalized Recommendation Diversity

Personalized recommendation has important implications in raising online shopping efficiency and increasing product sales. There has been wide interest in finding ways to provide more efficient personalized recommendations. Most existing studies focus on how to improve the accuracy of the recommendation algorithms, or are more concerned on ways to increase consumer satisfaction. Unlike these studies, our study focuses on the process of decision-making, using long tail theory as a basis, to reveal the mechanisms involved in consumers’ adoption of recommendations. This paper analyzes the effect of personalized recommendations from two angles: product sales and ratings, and tries to point out differences in consumer preferences between mainstream products and niche products, high rating products and low rating products, search products and experience products. The study verifies that consumers demand diversity in the recommended content, and also provides suggestions on how to better plan and operate a personalized recommendation system

Coordination Control of a Dual-Arm Exoskeleton Robot Using Human Impedance Transfer Skills

This paper has developed a coordination control method for a dual-arm exoskeleton robot based on human impedance transfer skills, where the left (master) robot arm extracts the human limb impedance stiffness and position profiles, and then transfers the information to the right (slave) arm of the exoskeleton. A computationally efficient model of the arm endpoint stiffness behavior is developed and a co-contraction index is defined using muscular activities of a dominant antagonistic muscle pair. A reference command consisting of the stiffness and position profiles of the operator is computed and realized by one robot in real-time. Considering the dynamics uncertainties of the robotic exoskeleton, an adaptive-robust impedance controller in task space is proposed to drive the slave arm tracking the desired trajectories with convergent errors. To verify the robustness of the developed approach, a study of combining adaptive control and human impedance transfer control under the presence of unknown interactive forces is conducted. The experimental results of this paper suggest that the proposed control method enables the subjects to execute a coordination control task on a dual-arm exoskeleton robot by transferring the stiffness from the human arm to the slave robot arm, which turns out to be effective

Differentially private multidimensional data publishing

© 2017, Springer-Verlag London Ltd., part of Springer Nature. Various organizations collect data about individuals for various reasons, such as service improvement. In order to mine the collected data for useful information, data publishing has become a common practice among those organizations and data analysts, research institutes, or simply the general public. The quality of published data significantly affects the accuracy of the data analysis and thus affects decision making at the corporate level. In this study, we explore the research area of privacy-preserving data publishing, i.e., publishing high-quality data without compromising the privacy of the individuals whose data are being published. Syntactic privacy models, such as k-anonymity, impose syntactic privacy requirements and make certain assumptions about an adversary’s background knowledge. To address this shortcoming, we adopt differential privacy, a rigorous privacy model that is independent of any adversary’s knowledge and insensitive to the underlying data. The published data should preserve individuals’ privacy, yet remain useful for analysis. To maintain data utility, we propose DiffMulti, a workload-aware and differentially private algorithm that employs multidimensional generalization. We devise an efficient implementation to the proposed algorithm and use a real-life data set for experimental analysis. We evaluate the performance of our method in terms of data utility, efficiency, and scalability. When compared to closely related existing methods, DiffMulti significantly improved data utility, in some cases, by orders of magnitude

Room-Temperature High-Performance H2S Sensor Based on Porous CuO Nanosheets Prepared by Hydrothermal Method

Porous CuO nanosheets were prepared on alumina tubes using a facile hydrothermal method, and their morphology, microstructure, and gas-sensing properties were investigated. The monoclinic CuO nanosheets had an average thickness of 62.5 nm and were embedded with numerous holes with diameters ranging from 5 to 17 nm. The porous CuO nanosheets were used to fabricate gas sensors to detect hydrogen sulfide (H2S) operating at room temperature. The sensor showed a good response sensitivity of 1.25 with respond/recovery times of 234 and 76 s, respectively, when tested with the H2S concentrations as low as 10 ppb. It also showed a remarkably high selectivity to the H2S, but only minor responses to other gases such as SO2, NO, NO2, H2, CO, and C2H5OH. The working principle of the porous CuO nanosheet based sensor to detect the H2S was identified to be the phase transition from semiconducting CuO to a metallic conducting CuS

Facile synthesis of α-Fe2O3 micro-ellipsoids by surfactant-free hydrothermal method for sub-ppm level H2S detection

The α-Fe2O3 micro-ellipsoids were prepared using a facile hydrothermal process without any surfactant or template, and their morphological, structural and H2S sensing properties were investigated. The α-Fe2O3 showed uniform micro-ellipsoids with a long axis diameter of 1.7 μm and a short axis diameter of 1.2 μm. Detailed structural analysis confirmed that the synthesized α-Fe2O3 micro-ellipsoids were compact particles with a hexagonal structure. Gas sensor base on the α-Fe2O3 micro-ellipsoids showed excellent response, short response/recovery time (< 90 s and 30 s, respectively), low detection concentration (~ 0.5 ppm), good long-term stability and excellent selectivity towards H2S gas at the optimized operating temperature of 350 °C. The sensing mechanism of the sensor based on the α-Fe2O3 micro-ellipsoids towards H2S was discussed

High precision NH3 sensing using network nano-sheet Co3O4 arrays based sensor at room temperature

Network nano-sheet arrays of Co3O4 for high precision NH3 sensing application were prepared on alumina tube using a facile hydrothermal process without template or surfactant, and their morphology, nanostructures and NH3 gas sensing performance were investigated. The prepared nano-sheet Co3O4 arrays showed a network structure with an average sheet thickness of 39.5 nm. Detailed structural analysis confirmed that the synthesized Co3O4 nano-sheets were consisted of nanoparticles with an average diameter of 20.0 nm. NH3 gas sensor based on these network Co3O4 nano-sheet arrays showed a low detection limit (0.2 ppm), rapid response/recovery time (9 s/134 s for 0.2 ppm NH3), good reproducibility and long-term stability for NH3 detection at room temperature

OR-032 Effects of Protein Supplement Timing during 4-Week Resistance Training on Muscle Hypertrophy in Males

Objective Nutrient timing is a new system of exercise nutrition that can help improve strength and lean body mass in a short time and does not require a change in exercise plan and energy intake. The concept of nutrient timing began to be used to solve problems such as the stagnation of muscle strength growth in high-protein diets, high quality proteins to gain weight and strength, but to obtain and utilize nutrient supplements at the right time to maximize muscle growth. Therefore, it is necessary to supplement the appropriate nutrients at different times. At present, some studies have found that the type and protein supplementation timing have some influence on the resistance training of high-level athletes. Protein supplementation before or after exercise plays a positive role in improving sports performance, recovery after exercise, muscle hypertrophy and muscle strength improvement. Due to the different types, dosage and time of protein supplementation, there are still some differences. It is still necessary to study the effect of nutrient timing of whey protein and the CEUS on the morphological indices of the rectus femoris. Therefore, by observing the thickness, circumference and area of the rectus femoris, we observed the effect of different nutrient timing and lower limb strength training on the shape of rectus femoris in healthy male youth. It is suggested that the different timing and dosage produce different effects and provide scientific suggestions for the later strength training and whey protein supplementation. Methods A total of 32 healthy male students participated in a randomized, double-blind, placebo-controlled study. Subjects were randomly divided into four groups, the control group (Group A), the pre-exercise supplementary group (Group B), the after-exercise supplementary group (Group C) and both pre-exercise and after-exercise supplementary group (Group D), which were supplemented by: two bottles of placebo before and after the training in Group A. two bottles of whey protein water before training and two bottles of placebo after training in Group B. two bottles of placebo before training and two bottles of whey protein water after training in Group C. two bottles of whey protein water before and after training in Group D. the bottles of supplements before training should be supplemented half an hour before the start of training, and the bottles of supplements after training should be supplemented within half an hour after training. Each bottle of whey protein water was 350ml which contained 15g whey protein. The training method was 70% 1RM for barbell squat, 4 sets of 10 times, each set rest for 60s. Three training sessions were conducted each week, and the training lasted for four weeks. During this period, in order to deal with the training effect, at the end of the second week, we performed a maximum squat strength test to adjust the training intensity for the following two weeks. The body composition test used GE lunar IDXA, a dual-energy X-ray scanning method and the indexes were body weight, muscle mass and FFM. The CEUS used GE Vivid 7 holographic Color Doppler Ultrasound Diagnostic system. The test sites of CEUS were in the anterior superior iliac crest and the upper margin of the patella 1/4, and the indexes were the thickness of the femoral rectus femoris, the circumference of the rectus femoris, and the cross-sectional area of the femoral rectus femoris. Tests were performed before and after 4-week resistance training. After the intervention, the variance of paired sample t test and One Way ANOVA were used to test the significance of each group. Results According to the change of the body composition, compared with the control group (Group A), the FFM of Group B, Group C and Group D were decreased, but there were no significant differences (p&gt;0.05). The muscle mass of Group C increased from 54.53±4.64 kg to 58.54±5.82 kg, and muscle mass of Group D increased from 55.74±4.09 kg to 58.75±4.74 kg, compared to group A, Group C and Group D had significant increase in muscle mass (p&lt;0.05). Body composition is mainly composed of adipose tissue and lean tissue, the body composition is influenced by the acquired factors, resistance training will also decrease the FFM and the increase the lean weight. Combined with 4-week resistance training with protein supplementation, we can see that the FFM in Group B, Group C and Group D declined a lot, which may be related to protein supplementation. The muscle mass of Group C and Group D were significantly improved, it was indicated that after resistance training, protein supplementation can improve muscle mass, but there was no differences between Group C and Group D, which indicates that the increase of protein supplementation has little effect on the increase of muscle mass, which may be due to the increase of protein supplement, the amount of muscle synthesis will increase, but the amount of decomposition will increase, too. In addition, the changes in the synthesis and decomposition, resulting in little change in muscle mass. About the morphological changes of rectus femoris in dominant leg, compared with the control group (Group A), the thickness of the rectus femoris (changed from 12.55±3.94 mm to 16.71±3.04 mm), the circumference of the rectus femoris (changed from 8.38±1.98 cm to 10.08±1.79 cm), the cross-sectional area of the rectus femoris (changed from 3.64±1.91 cm2 to 5.43±1.61 cm2) in Group C and the thickness of the rectus femoris (changed from 14.12±2.33 mm to 15.91±2.10 mm) in Group D were significantly increased (P&lt;0.05). The thickness of the rectus femoris, the circumference of the rectus femoris, the cross-sectional area of the rectus femoris in Group B and the circumference of the rectus femoris and the cross-sectional area of the rectus femoris in Group D were also increased, but there were no significant changes (p&gt;0.05). About the morphological changes of rectus femoris in non-dominant leg, compared with the control group (Group A), the thickness of the rectus femoris (changed from 13.54±3.82 mm to 16.77±3.37 mm), the cross-sectional area of the rectus femoris (changed from 4.07±2.11 cm2 to 5.42±1.86 cm2) in Group C and the thickness of the rectus femoris (changed from 13.46±2.91 mm to 16.39±1.24 mm) in Group D were significantly increased (P&lt;0.05). The thickness of the rectus femoris, the circumference of the rectus femoris, the cross-sectional area of the rectus femoris in Group B, the circumference of the rectus femoris in Group C and the circumference of the rectus femoris and the cross-sectional area of the rectus femoris in Group D were also increased, but there were no significant changes (p&gt;0.05). It could be seen from the results that the thickness, circumference and cross-sectional area of rectus femoris in Group C and Group D had a significant increase, and the change in Group B was not significant, indicating that after resistance training, protein supplementation will have better effects, more conducive to promoting the synthesis of muscle protein, so that the morphology of muscle was more obvious. From the comparison between Group C and Group D, we can see that the morphology of the rectus femoris in Group C has a significant change, although there were significant changes in the thickness of the rectus femoris in Group D, there was no significant increase in the circumference and cross-sectional area of the rectus femoris, which showed that the increase of protein supplementation had little effect on the morphology of the rectus femoris. This may be related to the synthesis and decomposition rate of the muscle, the increase in protein intake, to some extent, accelerated the rate of muscle synthesis, but the rate of decomposition of the muscle will also be accelerated, the synthesis rate and the rate of decomposition to achieve a positive balance. The rectus femoris of Group D will have a significant increase, but compared to group C, the effects were not obvious. Conclusions For the nutrient timing of the whey protein, taking whey protein after exercise is the better timing to improve the thickness, circumference, cross-sectional area of rectus femoris and the muscle mass by the lower limb resistance training for males. There is a certain effect on the reduction of body FFM, but no significant improvement is found. The increase of whey protein supplementation may have little effect on body composition and muscle hypertrophy