Search Space Pruning Based on Image Tools for Preliminary Interplanetary Trajectory Design

A novel gravity assist space pruning(GASP)algorithm based on image tools is proposed for solving interplanetary trajectory optimization problem.Compared with traditional GASP algorithm,the concept of image is introduced to avoid missing interesting solutions with appropriate number of function evaluations.Image tools allow us to evaluate the objective function in regions in place of points and provide an effective way to evaluate the forward and backward constraints for the multi-gravity assist trajectory optimization problem.Since the interesting solutions of the interplanetary trajectory optimization problem are often clustered in a small portion of the search space rather than being overall evenly distributed,the regionwise evaluations with image tools make the little large interval with the proper Lipschitzian tolerances sampling effective.The detailed steps of the proposed method are presented and two examples including Earth Venus Mars(EVM)transfer and Earth Venus Venus Earth Jupiter Saturn(EVVEJS)transfer are given.Finally,a comparison with solutions given by the literature demonstrates the effectiveness of the proposed method.

Diffusion tensor imaging as a tool to detect presymptomatic axonal degeneration in a preclinical spinal cord model of amyotrophic lateral sclerosis

The G93A-SOD1 mice model and MRI diffusion as a preclinical tool to study amyotrophic lateral sclerosis （ALS）： ALS is a progressive neurological disease characterized primarily by the development of limb paralysis, which eventually leads to lack of control on muscles under voluntary control and death within 3–5 years. Genetic heterogeneity and environmental factors play a critical role in the rate of disease progression and patients display faster declines once the symptoms have manifested. Since its original discovery, ALS has been associated with pathological alterations in motor neurons located in the spinal cord （SC）, where neuronal loss by a mutation in the protein superoxide dismutase in parenthesis （mSOD1） and impairment in axonal connectivity, have been linked to early functional impairments. In addition,mechanisms of neuroinflammation, apoptosis, necroptosis and autophagy have been also implicated in the development of this disease. Among different animal models developed to study ALS, the transgenic G93A-SOD1 mouse has become recognized as a benchmark model for preclinical screening of ALS therapies. Furthermore, the progressive alterations in the locomotor phenotype expressed in this model closely resemble the progressive lower limb dysfunction of ALS patients. Among other imaging tools, MR diffusion tensor imaging （DTI） has emerged as a crucial, noninvasive and real time neuroimaging tool to gather information in ALS. One of the current concerns with the use of DTI is the lack of biological validation of the microstructural information given by this technique. Although clinical studies using DTI can provide a remarkable insight on the targets of neurodegeneration and disease course,they lack histological correlations. To address these shortcomings, preclinical models can be designed to validate the microstructural information unveiled by this particular MRI technique. Thus, the scope of this review is to describe how MRI diffusion and optical microscopy evaluate axonal structural changes at early stages of the disease in a preclinical model of ALS.

Bidirectional link between diabetes mellitus and coronavirus disease 2019 leading to cardiovascular disease:A narrative review

Coronavirus disease 2019(COVID-19)is a global pandemic where several comorbidities have been shown to have a significant effect on mortality.Patients with diabetes mellitus(DM)have a higher mortality rate than non-DM patients if they get COVID-19.Recent studies have indicated that patients with a history of diabetes can increase the risk of severe acute respiratory syndrome coronavirus 2 infection.Additionally,patients without any history of diabetes can acquire newonset DM when infected with COVID-19.Thus,there is a need to explore the bidirectional link between these two conditions,confirming the vicious loop between“DM/COVID-19”.This narrative review presents(1)the bidirectional association between the DM and COVID-19,(2)the manifestations of the DM/COVID-19 loop leading to cardiovascular disease,(3)an understanding of primary and secondary factors that influence mortality due to the DM/COVID-19 loop,(4)the role of vitamin-D in DM patients during COVID-19,and finally,(5)the monitoring tools for tracking atherosclerosis burden in DM patients during COVID-19 and“COVID-triggered DM”patients.We conclude that the bidirectional nature of DM/COVID-19 causes acceleration towards cardiovascular events.Due to this alarming condition,early monitoring of atherosclerotic burden is required in“Diabetes patients during COVID-19”or“new-onset Diabetes triggered by COVID-19 in Non-Diabetes patients”.

Fast calculation of wave front amplitude propagation: a tool to analyze the 3D image on a hologram(Invited Paper)

A simple approach to calculate the amplitude component of a wave front propagating in space from a hologram is proposed. It is able to calculate the amplitude distribution on a plane at any distance rapidly using a standard GPU. This is useful for analyzing and reconstructing the 3D image encoded on a hologram.

球墨铸铁材料成分分析与研究

本文研究显微照相的原理并利用显微照相及暗室技术,使用打磨、抛光标准步骤处理球墨铸铁得到标准试验样品,随后使用光学显微镜观察其微观组织结构,并使用规则阵点法测量球墨铸铁样品的成分密度百分比,最后使用Image Tool软件拟合实验数据得到平均成分占比,球铁平均成分占比为0.77。

Landscape Characterization of Sariska National Park (India) and Its Surroundings

Landscape characterization gives an overall information on the status of Land Use and Land Cover （LULC）, changes in its composition and the impact of natural and human influences operating at different spatial and temporal scales. This information can be used to monitor changes in natural forest resources and protected areas, delineate potential conservation areas and can serve in effective management of ecologically fragile landscapes. In the present study, geo-spatial tools were used to characterize the landscape of Sariska National Park and its surroundings. Satellite data was used to prepare LULC maps for 1989 and 2000, change detection analysis and computation of landscape metrics. Climatic data, field records and modeling tools were used to map the potential spread of two invasive species, Prosopis juliflora and Adhatoda vasica. The results show that the forest area increased from 1989 to 2000, indicating better management practices. Landscape metrics （PAFRAC, PLADJ and AI） also support this argument. Improvements in the degraded forest can further enhance this effect. The entire reserve however is suitable for the invasion of P. juliflora and A. vasiea but is more pronounced in Boswellia serrata and Anogeissus pendula - Acacia catechu （open） forests. A detailed landscape characterization map can help forest managers to make important policy decisions concerning issues such as invasive species.