Multimedia social networks (MSNs) provide great convenience to users, while privacy leaks issues are becoming prominent. The studies on relationship-based access control have been widely used in social networks. However, with the dynamic development of social networks and rapid growth of user information, the access control does not completely meet the current system's need. In this paper, an attribute-based access control model called ABAC{MSN is proposed for MSNs. This model comprehensively considers user attributes, environment attributes and resource attributes, not only including relationships among users. In this model, users can set multimedia usage control policies based on three categories of user-defined attributes. A formal theoretical model is established, which includes constraint rules, data ow rules, policy conflict resolution mechanism, and applied to CyVOD.net, a multimedia social-network-platform prototype systems. The deployment and application denote that this method effectively and exibly addresses use-case scenarios of multi-attribute-based media access control, and improves the access security of social media platforms and resources.
The hyperpolarization-activated cyclic-nucleotide-gated
non-selective cation (HCN) channels play a potential role in the
neurological basis underlying drug addiction. However, little is
known about the role of HCN channels in methamphetamine
(METH) abuse. In the present study, we examined the changes
in working memory functions of METH re-exposed mice through
Morris water maze test, and investigated the protein expression
of HCN1 channels and potential mechanisms underlying the
modulation of HCN channels by Western blotting analysis. Mice
were injected with METH (1 mg/kg, i.p.) once per day for
6 consecutive days. After 5 days without METH, mice were
re-exposed to METH at the same concentration. We found that
METH re-exposure caused an enhancement of working memory,
and a decrease in the HCN1 channels protein expression in both
hippocampus and prefrontal cortex. The phosphorylated
extracellular regulated protein kinase 1/2 (p-ERK1/2),
an important regulator of HCN channels, was also obviously
reduced in hippocampus and prefrontal cortex of mice with METH
re-exposure. Meanwhile, acute METH exposure did not affect the
working memory function and the protein expressions of HCN1
channels and p-ERK1/2. Overall, our data firstly showed the
aberrant protein expression of HCN1 channels in METH
re-exposed mice with enhanced working memory, which was
probably related to the down-regulation of p-ERK1/2 protein
expression.
Microblogging filtering is intended to filter out irrelevant content, and select useful, new, and timely content from microblogs. However, microblogging filtering suffers from the problem of insufficient samples which renders the probabilistic models unreliable. To mitigate this problem, a novel method is proposed in this study. It is believed that an explicit brief query is only an abstract of the user's information needs, and its difficult to infer users' actual searching intents and interests. Based on this belief, a filtering model is built where the multi-sources query expansion in microblogging filtering is exploited and expanded query is submitted as users interest. To manage the external expansion risk, a user filter graph inference method is proposed, which is characterized by combination of external multi-sources information, and a risk minimization filtering model is introduced to achieve the best reasoning through the multi-sources expansion. A series of experiments are conducted to evaluate the effectiveness of proposed framework on an annotated tweets corpus. The results of these experiments show that our method is effective in tweets retrieval as compared with the baseline standards.
Diabetic or hyperglycaemic conditions stimulate the inflammatory response, excessive accumulation of extracellular matrix, and result in glomerulosclerosis, a scarring process of diabetic nephropathy. c-Jun activation domain-binding protein 1 (JAB1) functions as a regulator of pathways involved in cellular apoptosis and proliferation. The role of JAB1 in diabetic nephropathy was investigated in this study. Firstly, glomerular mesangial cells (GMCs) were treated with high glucose, and high glucose conditions induced up-regulation of JAB1 in the GMCs. Moreover, IL-6, TNF-α, MCP-1, and IL-1β were also elevated in high glucose-induced GMCs. Secondly, silencing of JAB1 reduced the levels of IL-6, TNF-α, MCP-1, and IL-1β in high glucose-induced GMCs. In addition, silencing of JAB1 attenuated the high glucose-induced decrease of superoxide dismutase (SOD) and the increase of reactive oxygen species (ROS) and malondialdehyde (MDA). The increased TGF-β1, collagen I, collagen IV, and fibronectin levels in high glucose-induced GMCs were restored by knockdown of JAB1. Thirdly, angiopoietin-like protein 2 (ANGPTL2) expression was reduced by JAB1. Over-expression of ANGPTL2 weakened the JAB1 silence-induced decrease of IL-6, TNF-α, MCP-1, IL-1β, TGF-β1, collagen I, collagen IV, and fibronectin. In conclusion, silencing of JAB1 reduced extracellular matrix deposition and suppressed inflammation in high glucose-induced GMCs through down-regulation of ANGPTL2.
To uncover adaptation capacities of two flooding-tolerant plant species, Pterocarya stenoptera (a native species) and Pinus elliottii (an exotic species from southeastern USA), to alternating submergence and drought, we investigated their physiological and growth responses to water stress. Water treatments, including control, continuous flooding (CF), and periodic flooding and drought (PF), were applied to seedlings in order to simulate water level fluctuation in the hydrofluctuation zone of the Three Gorges Reservoir Region. Results showed that net photosynthetic rate (P N), stomatal conductance, and intrinsic water-use efficiency of both plant species were negatively affected under CF and PF compared with the corresponding controls. The P N of both species under PF was comparable to that under CF. At the end of the experiment, the ratio of intercellular to ambient CO2 concentration was not statistically different between water treatments, while that of P. elliottii was significantly higher than that of P. stenoptera. Although P. stenoptera formed lenticels under flooding conditions, P. elliottii seedlings allocated more mass to leaves and increased the relative growth rate of height to enhance the photosynthetic efficiency. Our results illustrated that P. stenoptera and P. elliottii seedlings developed different adaptive strategies in response to flooding, both CF and PF. Therefore, both P. stenoptera and P. elliottii are promising candidates for the vegetation reconstruction of the riparian zones in the Three Gorges Reservoir Region., Y. Yang, C. Li., and Obsahuje seznam literatury
In three separate experiments, the effectiveness of a SPAD-502 portable chlorophyll (Chl) meter was evaluated for estimating Chl content in leaves of Eugenia uniflora seedlings in different light environments and subjected to soil flooding. In the first experiment, plants were grown in partial or full sunlight. In the second experiment plants were grown in full sunlight for six months and then transferred to partial sunlight or kept in full sunlight. In the third experiment plants were grown in a shade house (40% of full sunlight) for six months and then transferred to partial shade (25-30% of full sunlight) or full sunlight. In each experiment, plants in each light environment were either flooded or not flooded. Non-linear regression models were used to relate SPAD values to leaf Chl content using a combination of the data obtained from all three experiments. There were no significant effects of flooding treatments or interactions between light and flooding treatments on any variable analyzed. Light environment significantly affected SPAD values, chlorophyll a (Chl a), chlorophyll b (Chl b), and total chlorophyll [Chl (a+b)] contents in Experiment I (p≤0.01) and Experiment III (p≤0.05). The relationships between SPAD values and Chl contents were very similar among the three experiments and did not appear to be influenced by light or flooding treatments. There were high positive exponential relationships between SPAD values and Chl (a+b), Chl a, and Chl b contents. and M. S. Mielke, B. Schaffer, C. Li.