A Trajectory Privacy Protection Method to Resist Long-Term Observation Attacks

Users face the threat of trajectory privacy leakage when using location-based service applications, especially when their behavior is collected and stored for a long period of time. This accumulated information is exploited by opponents, greatly increasing the risk of trajectory privacy leakage. This attack method is called a long-term observation attack. On the premise of ensuring lower time overhead and higher cache contribution rate, the existing methods cannot utilize cache to answer subsequent queries while also resisting long-term observation attacks. So this article proposes a trajectory privacy protection method to resist long-term observation attacks. This method combines caching technology and improves the existing differential privacy mechanism, while incorporating randomization factors that are difficult for attackers to recognize after long-term observation to enhance privacy. Search for locations in the cache of both the mobile client and edge server that can replace the user’s actual location. If there are replacement users in the cache, the query results can be obtained more quickly. Simultaneously obfuscating the spatiotemporal correlation of actual trajectories by generating confusion regions. If it does not exist, the obfuscated location generation method that resists long-term observation attacks is executed to generate the real anonymous area and send it to the service provider. The above steps can comprehensively protect the user’s trajectory privacy. The experimental results show that this method can protect user trajectories from long-term observation attacks while ensuring low time overhead and a high cache contribution rate.

Dynamics of Bottom Boundary Layers in the Yellow River Subaqueous Delta Based on Long-Term In-Situ Observations

Objective In geo-marine science,the generalized bottom boundary layer（BBL）represents a layer between sediments and seawater.The BBL plays an important role in geological,geobiochemical,geophysical and geotechnical research because it is the connection region of hydrosphere,

Long-Term Geophysical Observations and Analysis of the World's Deepest Borehole

Objective In order to reduce the interfering noise from the earth surface, scientists have carried out multi-geophysical borehole observations and the related study. This study aims at improving signal-to-noise ratio obtained from the observation data to obtain zero noise data, which will be of great help to improve geophysical studies. Insights from this study will be significant for the earthquake disaster reduction, resource exploration and environmental protection.

Ocean current observation and spectrum analysis in central Chukchi Sea during the summer of 2008

During the summer of 2008, the third CHINARE Arctic Expedition was carried out on board of Xuelong Icebreaker in the central Chukchi Sea. A submersible mooring system was deployed and recovered at Station CN-01 （71.40.024＇N, 167.58.910＇W） with 33 days of the current profile records, and continuous observation of temperature and salinity data were collected. This mooring station locates in the blank of similar observation area and it is the first time for our Chinese to finish this kind of long-term mooring work in this area. This mooring system finished integrated hydrological observations with long-term continuous record of the whole profile velocity for the first time. Based on time series analysis of temperature, salinity, velocity and flow direction, we get the following main results. （1） During the observation period, the mean surface current velocity is 70.2 cm/s eastward, and velocity reaches its maximum in average at 3 m level with magnitude 90.0 cm/s, direction 206.. （2） In 9-30 m layers, the semidiurnal period variation is the most obvious, the flow direction is quite stable, and the flow is synchronous and consistent vertically. （3） Besides the semidiurnal period variation, the main variation in the upper layer is in 11-d period, with variations in period 5.5, 5.5, and 3.7 d, which reflect the influences of sea surface wind change and maintenance. （4） Near the bottom the temperature change is correlated and synchronized with the conductivity.

Predictors of Discontinuation of Antipsychotic Therapy in Patients with Acute Schizophrenia: A 1-Year Observational Study with More Than 1000 Patients

Discontinuation of antipsychotic therapy has been a significant clinical issue among patients with schizophrenia, since the patients who discontinued antipsychotic treatment showed worse clinical and functional outcomes, and higher risks of relapse of schizophrenia symptoms and hospitalization. We conducted a post-hoc analysis of a post-marketing research with a 12-month follow-up period to identify the predictors for discontinuation of antipsychotic monotherapy in Japan. This is a prospective, naturalistic multicenter observational study, designed to evaluate the discontinuation rates of olanzapine monotherapy and non-olanzapine antipsychotic monotherapy in Japanese adult patients with acute schizophrenia. Patients were treatment-naive, or had switched from other antipsychotics or from poly-pharmacotherapy to oral antipsychotic monotherapy. We analyzed the correlation of discontinuation of antipsychotic monotherapy with baseline characteristics of patients. A total of 1089 patients (578 patients treated with olanzapine and 511 with non-olanzapine antipsychotics) were eligible for analysis. By the end of the 12-month study period, 614 patients (56.4%) discontinued antipsychotic therapy. Multivariate logistic regression analyses indicated significantly lower discontinuation rates in all patients treated with antipsychotics: older age (Odds ratio [OR], 0.871;95% confidence interval [CI], 0.797 to 0.953;p = 0.003), outpatient status (OR, 0.508;95% CI, 0.383 to 0.675;p < 0.001), prior use of antipsychotics (OR, 0.693;95% CI, 0.516 to 0.930;p = 0.015), and olanzapine group showed lower discontinuation rate than that of non-olanzapine group (OR, 1.416;95% CI, 1.086 to 1.846;p = 0.010). The present study indicated that the outpatient status, older age, and prior use of antipsychotics have better adherence to antipsychotic treatment. In addition to these factors, use of anti-parkinson agents showed lower discontinuation rates in the olanzapine monotherapy group.

Covariability of Subantarctic Mode Water and the Southern Branch of the Subtropical Indian Ocean Countercurrent in Argo Observations

The Subantarctic Mode Water(SAMW)forms in the deep mixed layer north of the Antarctic Circumpolar Current and spreads northward into the subtropical gyre.The subtropical South Indian Countercurrent(SICC)flows eastward on the north flank of the thick SAMW layer within 22°-32°S from south of Madagascar at around 25°S,50°E toward western Australia.The dynamical relation of the SAMW and the southern branch of the SICC(30°-32°S)is investigated in this work based on the monthly mean Argo data from 2004 to 2019.The physical properties of the SAMW and its pathway from the formation region are described.Most of the SAMW in the Indian Ocean sector originates from the deep mixed layers of the southeastern Indian Ocean(about 40°S,85°-105°E)and moves along the subtropical gyre.It takes around ten years to arrive east of Madagascar Island preserving its low potential vor-ticity characteristics.As a thick layer with homogeneous vertical properties,the SAMW forces the upper pycnocline to shoal,and the associated eastward shear results in the surface-intensified SICC.The SAMW forms a tongue-shaped thickness pattern,which influ-ences the southern branch of the SICC above the northern flank of the thickest SAMW layer between 24°S and 32°S.The seasonal,interannual,and decade variations of the southern branch of the SICC are closely related to the meridional gradient of the underlying SAMW thickness.The SAMW thickened and strengthened from 2005 to 2015,thereby anchoring a strengthened SICC.The interan-nual covariability of the SAMW and SICC further supports the SAMW’s role in driving SICC variability.

Oncological results, functional outcomes and health-related quality-of-life in men who received a radical prostatectomy or external beam radiation therapy for localized prostate cancer： a study on long-term patient outcome with risk stratification

Health-related quality-of-life （HRQOL） after a radical prostatectomy （RP） or extemal beam radiation therapy （EBRT） has not been studied in conjunction with oncological outcomes in relation to disease risk stratification. Moreover, the long-term outcomes of these treatment approaches have not been studied. We retrospectively analyzed oncological outcomes between consecutive patients receiving RP （n = 86） and EBRT （n = 76） for localized prostate cancer. HRQOL and functional outcomes could be assessed in 62 RP （79%） and 54 EBRT （79%） patients over a 3-year follow-up period （median： 41 months） using the Medical Outcomes Study Short Form-36 （SF-36） and the University of Califomia Los Angeles Prostate Cancer Index （UCLA PCI）. The 5-year biochemical progression-free survival did not differ between the RP and EBRT groups for low-risk （74.6% vs. 75.0%, P = 0.931） and intermediate-risk （61.3% vs. 71.1%, P = 0.691） patients. For high-risk patients, progression-free survival was lower in the RP group （45.1%） than in the EBRT group （79.7%） （P = 0.002）. The general HRQOL was comparable between the two groups. Regarding functional outcomes, the RP group reported lower scores on urinary function and less urinary bother and sexual bother than the EBRT group （P 〈 0.001, P 〈 0.05 and P 〈 0.001, respectively）. With risk stratification, the low- and intermediate-risk patients in the RP group reported poorer urinary function than patients in the EBRT group （P 〈 0.001 for each）. The sexual function of the high-risk patients in the EBRT group was better than that of the same risk RP patients （P 〈 0.001）. Biochemical recurrence was not associated with the UCLA PCI score in either group. In conclusion, low- to intermediate-risk patients treated with an RP may report relatively decreased urinary function during long-term follow-up. The patient＇s HRQOL after treatment did not depend on biochemical recurrence.

June to October Aerosol Optical Depth over the Arctic at Various Spatial and Temporal Scales in MODIS, MAIAC, CALIOP and GOES Data

The accuracy of the cloud-aerosol lidar with orthogonal polarization (CALIOP), moderate resolution imaging spectroradiometer (MODIS), Multi-Angle Implementation of Atmospheric Correction (MAIAC), and Geostationary Operational Environmental Satellite (GOES) aerosol optical depth (AOD) products for the Arctic north of 59.75°N was examined by means of 35 aerosol robotic network (AERONET) AOD sites. The assessment for June to October 2006 to 2020 showed MAIAC AOD agreed the best with AERONET AOD;CALIOP AOD differed the strongest from the AERONET AOD. Cross-correlations of CALIOP AOD along the satellite path indicated that AOD-values 40 km up-and-down the path often failed to represent the AERONET AOD-values within ±30 min of the overpass in this region dominated by easterly winds. Typically, CALIOP AOD was lower than AERONET AOD and MAIAC AOD at the sites, especially, at sites with mean AOD below 0.1. Generally, MODIS AOD values exceeded those of MAIAC. Comparison of CALIOP, MAIAC, and MODIS products resampled on a 0.25° × 0.25° grid revealed differences among the products caused by their temporal and spatial resolution, sample habit and size. Typically, the MODIS AOD-product showed the most details in AOD distribution. Despite differences in AOD-values, all products provided similar temporal evolution of elevated and lower AOD.

Characteristics of atmospheric nitrous oxide observed at Mt.Waliguan GAW global station in the inland Eurasia during eighteen years

This study presents atmospheric N_(2)O mole fractions measured from discrete air samples from 2001 to 2018 at Mt.Waliguan(WLG)station(36°17′N,100°54′E,3816 m asl)in China,which is a global background station of the World Meteorological Organization/Global Atmosphere Watch Programme(WMO/GAW)in central Eurasia.Observed N_(2)O characteristics of annual means,interannual variability,and seasonal cycles were investigated.Our results show that N_(2)O at WLG possess a distinct increasing trend and a statistically significant seasonal cycle,with an average growth rate of 0.9±0.01 ppb yr^(−1)(1σ)(1ppb=10^(−9)),which is close to the global mean.The detrended seasonal cycle shows a trough of−0.25±0.04(1σ)ppb in June and a peak of 0.13±0.07(1σ)ppb in September,with an amplitude of 0.38 ppb.The pattern is due to combined effects of variation in surface sources,vertical convection within the boundary layer and stratosphere to troposphere transportation(STE).The interannual variability in growth rate was partly driven by quasi-biennial oscillation(QBO)of tropical zonal wind through stratospheric transport into the troposphere.According to a cluster analysis of back trajectories and the corresponding average N_(2)O load,most air masses cover arid and semi-arid areas in inner Asia with low N_(2)O emissions,indicating that the atmospheric N_(2)O at the WLG represents the background N_(2)O level in central Eurasia.

页岩微纳观断裂的原位观测

为了准确理解岩石微纳观裂纹起裂、扩展及演化规律,在带有拉伸加载装置的扫描电子显微镜下,对含有预制边缘裂纹的"拱形"页岩试样进行单轴拉伸试验,实时观测预制边缘裂纹尖端部位的微纳观裂纹起裂及扩展过程。在裂纹贯通后,继续原位观测主断裂裂纹边缘次级微纳观分叉裂纹的展布特征。取出样品后,在扫描电子显微镜下观测断口形貌,基于上述显微观测分析了页岩微纳观裂纹扩展的力学过程。研究表明:(1)采用含有预制裂纹的"拱形"试样更易于成功观测到页岩预制裂纹尖端微纳观裂纹的起裂及稳定扩展过程。(2)微纳观裂纹一般从预制裂纹尖端部位萌生、起裂,裂纹的横向伸展与纵向延伸相伴发生,在快速的脆性断裂前,经历短暂的裂纹稳定扩展过程。(3)微纳观次级分叉裂纹一般从主断裂裂纹边缘的天然微裂纹等弱结构面处起裂和扩展,最终在主断裂裂纹边缘区域止裂,或者前缘发生转向并与主断裂裂纹汇合。(4)主断裂面揭露出页岩矿物晶体内部的天然微孔洞和解理面、层片状矿物的层理面以及天然微裂纹,这有利于在微纳观尺度上形成微孔洞和微裂纹网络,为页岩气开采提供有效的微观通道。

玄武岩纤维沥青混合料韧性研究及机理分析

为研究玄武岩纤维对沥青混合料韧性的影响,选用AC-13C和SMA-13两种混合料,使用UTM-25试验机对添加纤维前后的马歇尔试件进行间接拉伸试验;通过扫描电镜对纤维沥青混合料进行微观观测,分析纤维对混合料韧性的影响及增韧机理。试验结果表明:掺加玄武岩纤维对混合料的韧性指标有较大幅度提高,改善了混合料的抗开裂性能;纤维在沥青混合料中形成三维网状结构,且与沥青间有良好的粘结能力,使得裂纹扩展时的能量释放率减少从而延缓裂缝的扩展。

裸鼹鼠骨骼标本的制作及其形态学观察

目的采用传统方法制备裸鼹鼠骨骼标本，对其骨骼系统进行形态学观察。方法利用水煮法制作裸鼹鼠骨架，与C57BL／6J小鼠骨骼标本比较研究裸鼹鼠骨骼特点，并观察裸鼹鼠股骨三维结构。结果所制作的裸鼹鼠骨架完整洁净，没有骨质损伤，裸鼹鼠头骨、椎骨、肋骨、四肢骨均具有适应于穴居习性的特征。结论裸鼹鼠的骨骼具有典型的适应掘穴生活的特征。

应用品管圈提高呼吸内科住院病人痰标本送检率

目的探讨品管圈活动在提高呼吸内科住院病人痰标本送检率中的应用效果。方法皖南医学院弋矶山医院呼吸内科于2016年4月成立品管圈小组,确定活动主题,通过现状把握、目标设定、要因分析、对策拟定并实施,对活动前后呼吸内科住院病人痰标本送检率进行统计分析。结果实施品管圈后,住院病人痰标本送检率达到91.98%(χ~2=42.358,P<0.001),较活动前的62.07%有明显提高。结论品管圈能提高住院病人的痰标本送检率。

广州中医药大学“中药学”实践教学法探究

"中药学"是中医药各专业的基础学科之一,是联系中医基础理论与临床应用和药学其他学科的桥梁。为了提高该课程教学质量,让同学们具备扎实的基础知识,在采用普通课堂教学法外,广州中医药大学充分利用学校固有资源,采用课外实践教学法和标本观察教学法进行教学并取得很好的教学效果。本研究为"中药学"这一课程提供更多的教学借鉴经验。

临床标本的缺陷分析与流程再造的效果观察

目的对临床标本送检流程进行改进,规范标本的储存和运送流程,以降低临床标本的不合格率。方法成立标本流程再造团队,统计2014年1—12月及2015年1—12月的不合格的检验标本,绘制标本采集运送流程,分析临床标本送检的流程,对存在的缺陷环节进行分析,进而制定改进措施,对标本的采集、标本的存储、交接及运送进行流程优化再造。对比再造流程前后标本送检的不合格率。结果标本不合格率由2014年的2.73‰下降至2015年的2.12‰(P<0.01)。结论对临床标本运送流程进行分析改进,有效降低标本不合格率,提高标本管理的有效性,确保医疗护理安全。

肉眼直观区别股骨颈扭转角与前倾角

目的探讨肉眼直观下描述股骨颈扭转角及前倾角的区别,并分析其差异的临床意义。方法在股骨冠状面平面,分别从6点钟、12点钟、1∶30点钟、3点钟和4∶30点钟位置观察干燥完整的股骨标本(60根),在照片上分别确定股骨头颈轴线、股骨冠状面、股骨颈截面最长径及股骨上段冠状面,画图描述股骨颈扭转角与前倾角,分析这两个角度的区别。结果股骨颈前倾角是股骨头颈轴线与股骨冠状面的夹角,是线与面的关系,角尖朝内,在6点钟、12点钟、1∶30点钟、3点钟和4∶30点钟位均可观察到;股骨颈扭转角是股骨颈椭圆截面最长径线构成的面与股骨(上段)冠状面的夹角,是面与面的关系,角尖朝后,仅在12点钟、1∶30点钟、3点钟位可以观察到。1∶30钟位是显示股骨颈扭转角和前倾角区别的最佳位置。结论股骨颈前倾角和扭转角是共同基于股骨冠状面,分别与股骨头颈轴线、股骨颈截面最长径线构成的面,组成的两个不同角度参数。非立体观察是混淆股骨颈扭转角与前倾角的重要原因。前倾角决定内固定螺钉及股骨假体的方向,扭转角对内固定螺钉进钉点及股骨髓腔开口位置有参考价值。

阿式肠杆菌和萎缩芽孢杆菌扫描电镜样品制备观察和分析

通过阿式肠杆菌和萎缩芽孢杆菌样品制备的经验方法,在JSM-6700F电镜下得到形态完整高清晰的图像.培养获得高纯度的菌,采用双固定、磷酸缓冲液清洗、丙酮脱水、多次表面镀铂等对样品进行处理.结果是电镜观察样品形态的丰富度高;样品扫描图像有丰富的立体感;分辨率高图像更清晰.为其他生物扫描电镜观察提供了参考.

观察人体标本的方法

观察人体标本是医学生学习人体结构的一种有效途径。为了指导学生实验,提高实验教学的效果,总结了观察人体标本的方法。