Learning and memory impairment of aged female mice induced by chronic stress

Objective To study the mechanism of learning and memory impairment in aged female mice caused by chronic stress. Methods Twenty-month-old ICR mice were randomly divided into four groups: control females, control males, stressed females, and stressed males. Chronic stress was applied to the stress group for 30 days. The learning and memory ability was measured by novel object recognition test and Morris water maze test. Damage to hippocampal neurons was observed with Nissl staining, and dendrites of hippocampal neurons were observed with Golgi-Cox staining microscopy, the expression of the mammalian target of rapamycin (mTOR) and p-mTOR in hippocampal tissue was measured by Western blot, and the level of serum corticotropin-releasing hormone (CRH) was measured by ELISA. Results There was a significant decrease in the learning and memory ability only in the stressed female group after applied stress. In the Morris water maze, after a 6-day swimming training, the escape latency decreased in the control female group, the control male group and in the stressed male group(P＜0.001, P＜0.001, P＜0.05), but not in the stressed female group. The swimming speed was consistent across groups, but the number of platform crossings and the number of target quadrant crossings were significantly lower in the stressed female group than those in the control female and stressed male groups(P＜0.001).There was significant damage to neurons in the hippocampal CA3, CA1, and DG regions of mice in the stressed female group. The expression of hippocampal m-TOR and p-mTOR protein was significantly decreased in the stressed female group of mice(P＜0.05). In addition, chronic stress caused a significant increase in serum CRH levels in aged female mice(P＜0.05). Conclusions Chronic stress caused learning and memory impairment and pathological damage of the hippocampus in aged female mice, but not in aged male mice, which may be related to a fact that chronic stress elevates CRH and inhibits the hippocampal m-TOR signaling pathway in aged female mice

Shallow Water Bathymetry through Two-medium Photogrammetry Using High Resolution Satellite Imagery

This paper develops an automated shallow water bathymetry procedure based on two-medium photogrammetry using high resolution satellite multispectral imagery. In this method, near-infrared band were used for sunglint elimination and rational function model (RFM) was applied for raw DEM generation. By extracting the water-land edge and interpolating edge elevation, water surface position could be determined. An approximation refraction correction model, in which all homonymy lights were regarded as intersect to the same observed point, was adopted to correct the vertical offsets. Experimental results indicate that DEM accuracy of satellite two-medium photogrammetry is better than 20% of the average depth under the circumstance of relatively calm water and rich bottom texture

The Abnormal Accumulation of Lipopolysaccharide Secreted by Enriched Gram-Negative Bacteria Increases the Risk of Rotavirus Colonization in Young Adults

Human rotavirus (HRV) is an enteric virus that causes infantile diarrhea. However, the risk factors contributing to HRV colonization in young adults have not been thoroughly investigated. Here, we compared the differences in dietary habits and composition of gut microbiota between asymptomatic HRV-infected young adults and their healthy counterparts and investigated potential risk factors contributing to HRV colonization. Our results indicated that asymptomatic HRV-infected adults had an excessive intake of milk and dairy and high levels of veterinary antibiotics (VAs) and preferred veterinary antibiotic (PVAs) residues in urine samples. Their gut microbiota is characterized by abundant Gram-negative (G−) bacteria and high concentrations of lipopolysaccharide (LPS). Several opportunistic pathogens provide discriminatory power to asymptomatic, HRV-infected adults. Finally, we observed an association between HRV colonization and disrupted gut microbiota caused by the exposure to VAs and PVAs. Our study reveals the traits of disrupted gut microbiota in asymptomatic HRV-infected adults and provides a potential avenue for gut microbiota-based prevention strategies for HRV colonization

Towards Efficient Control Flow Handling in Spatial Architecture via Architecting the Control Flow Plane

Spatial architecture is a high-performance architecture that uses control flow graphs and data flow graphs as the computational model and producer/consumer models as the execution models. However, existing spatial architectures suffer from control flow handling challenges. Upon categorizing their PE execution models, we find that they lack autonomous, peer-to-peer, and temporally loosely-coupled control flow handling capability. This leads to limited performance in intensive control programs. A spatial architecture, Marionette, is proposed, with an explicit-designed control flow plane. The Control Flow Plane enables autonomous, peer-to-peer and temporally loosely-coupled control flow handling. The Proactive PE Configuration ensures timely and computation-overlapped configuration to improve handling Branch Divergence. The Agile PE Assignment enhance the pipeline performance of Imperfect Loops. We develop full stack of Marionette (ISA, compiler, simulator, RTL) and demonstrate that in a variety of challenging intensive control programs, compared to state-of-the-art spatial architectures, Marionette outperforms Softbrain, TIA, REVEL, and RipTide by geomean 2.88x, 3.38x, 1.55x, and 2.66x