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Time-Domain Full Waveform Inversion Using the Gradient Preconditioning Based on transmitted Wave Energy

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Journal of Ocean University of China 2019年第4期18卷 859-867页

作者： SONG Peng TAN Jun LIU Zhaolun ZHANG Xiaobo LIU Baohua YU Kaiben LI Jinshan XIA Dongming XIE Chuang College of Marine Geo-Sciences Ocean University of China Qingdao 266100 China Laboratory for Marine Mineral Resources Qingdao National Laboratory for Marine Science and Technology Qingdao 266100 China Key Laboratory of Submarine Geosciences and Prospecting Techniques Ministry of Education Ocean University of China Qingdao 266100 China Physical Science and Engineering Division (PSE) King Abdullah University of Science and Technology (KAUST) Thuwal 23955-6900 Saudi Arabia National Deep Sea Center Qingdao 266100 China

The gradient preconditioning approach based on seismic wave energy can effectively avoid the huge memory consumption of the gradient preconditioning algorithms based on the Hessian matrix. However, the accuracy of this approach is prone to be influ- enced by the energy of reflected waves. To tackle this problem, the paper proposes a new gradient preconditioning method based on the energy of transmitted waves. The approach scales the gradient through a precondition factor, which is calculated by the ‘ap- proximate transmission wavefield’ simulation based on the nonreflecting acoustic wave equation. The method requires no computing nor storing of the Hessian matrix and its inverse matrix. Furthermore, the proposed method can effectively eliminate the effects of geometric spreading and disproportionality in the gradient illumination. The results of model experiments show that the time-domain full waveform inversion (FWI) using the gradient preconditioning based on transmitted wave energy can achieve higher inversion accuracy for deep high-velocity bodies and their underlying strata in comparison with the one using the gradient preconditioning based on seismic wave energy. The field marine seismic data test shows that our proposed method is also highly applicable to the FWI of field marine seismic data.

关键词： full waveform inversion gradient preconditioning transmitted wave nonreflecting acoustic wave equation

The prevalence of transfusion transmitted virus infection in blood donors

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World Journal of Gastroenterology 2000年第2期6卷 268-270页

作者： Cheng Hui Huang Yu Sen Zhou Ru Guang Chen Chun Ying Xie Hai Tao Wang Department of Blood Transfusion Research Shenzhen Baoan Blood CenterShenzhen 518101Guangdong ProvinceChina Department of Hepatitis Virus Beijing Institute of Microbiology and EpidemiologyBeijing 100071China Department of Molecular Biology Shenzhen Baoan People’s HospitalShenzhen 518101Guangdong ProvinceChina

INIRODUCIIONA newly discovered DNA virus,transfusiontransmitted virus (TTV),was reported as a cause ofpost-transfusion hepatitis of unknown etiology *** order to investigate TTV prevalence insouthern China,a study was carried out amongblood donors,patients with liver diseases andhemodialysis to determine the epidemiologicalcharateristics.

关键词： transfusion transmitted virus infection blood donors liver diseases hemodialysis

Sexually transmitted Illnesses in Masvingo Province, 2012-2015: A Secondary Data Analysis

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Open Journal of Epidemiology 2017年第1期7卷 59-68页

作者： Noriah M. Hwami Tsitsi P. Juru Amadeus Shamu Gerald Shambira Notion Tafara Gombe Mufuta Tshimanga MPH Programme Department of Community Medicine University of Zimbabwe Harare Zimbabwe Provincial Medical Directorate Ministry of Health and Child Care Masvingo Zimbabwe

Background: Masvingo province is among the top three provinces with high Genital Ulcer Disease incidence rates in Zimbabwe. There has been no documented evidence to establish the burden and epidemiology of STIs in Masvingo province. We analysed these data to describe trends in STIs from 2012 - 2015. Methods: A retrospective records review of Masvingo STI data set was conducted. We assessed trends in STIs from 2012-2015. Microsoft Excel 2010 software was used to generate bar and linear graphs. Epi info 7TM was used to calculate Chi-square for trends and p values. Results: Most affected age group was 25 - 49 years (incidence rate of 73.9 cases per 1000). The 50 and above age group had a higher incidence rate than the 10 - 24 year age group (27.5 compared to 15.5 cases per 1000). STI incidence was higher in females (31.9 cases per 1000) than in males (20.6 cases per 1000). The most prevalent STIs were vaginal discharge 48,972 (30.7%) and other forms of STIs 35,777 (22.3%). Masvingo district recorded the highest STI incidence rate (34.1 cases per 1000). There was a decline in HIV testing rates from 36 (100%) to 12,190 (64.4%) (p Conclusion: There was a general decline in the STI trends for all age groups. Age group most affected by STIs was the 25 - 49 years with females being more affected. HIV testing services among STI clients declined. We recommend advocacy on safe sexual practices and further research to identify reasons for low uptake of HIV testing services among STI clients.

关键词： Sexually transmitted Illnesses Incidence Masvingo Zimbabwe

Risky Meetings Despite Knowledge of the Risk: A Qualitative Study of Young Adults Treated for Chlamydia Infection at a Sexual transmitted Infection Clinic

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Open Journal of Obstetrics and Gynecology 2018年第6期8卷 572-584页

作者： Annsofie Adolfsson Department of Dermato-Venereology Orebro University Hospital Orebro Sweden Department of Health Sciences Orebro University Orebro Sweden

The aim of the study was to describe the attitudes to risk behavior among patients diagnosed with a Chlamydia infection at a Sexual transmitted Infection (STI) clinic. Qualitative interviews face-to-face were conducted with twenty patients, aged 18 - 30 years, with confirmed Chlamydia infections were included. An interview guide was used and the participants described the behavior that had led to the infection. The material was analyzed using qualitative content analysis. Eighteen informants were included and the theme was risk. Recurrent among the informants was risk behavior in sexual relations when using alcohol, while risk behavior in life in general was almost non-existent. Of the 18 informants, sixteen had previously been tested for STIs, and ten had had an STI before. Alcohol consumption emerged as a common denominator among the informants and as a contributor to risk. In contrast, almost none of the informants exposed themselves to any unnecessary risks in life in general.

关键词： Risky Meetings Sexually transmitted Infections Young Adults Qualitative Method Content Analysis

A 10 Years Comparative Study to Assess Trends in Seroprevalence of Transfusion transmitted Infections among Blood Donors at Gwalior, India

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Open Journal of Blood Diseases 2014年第2期4卷 24-32页

作者： Dharmesh Chandra Sharma Sunita Rai Savita Bharat Sudha Iyenger Shruti Gupta Bharat Jain Department of Microbiology Gajra Raja Medical College Gwalior India Department of Pathology Blood Bank Gajra Raja Medical College Gwalior India

Introduction: Transfusion transmitted Infections (TTIs) threaten safety of the recipients and the community as a whole and are the subject of real concern worldwide. Aims and Objectives: To know the prevalence of transfusion transmitted infections amongst the blood donors, to evaluate the changing trends of TTIs and to compare these observations within the study as well as with the other relevant studies. Place and Duration of Study: This study was carried out at Blood Bank, Department of Pathology, Gajra Raja Medical College, Gwalior, India, from January 2004 to December 2013 (ten years). Materials and Methods: In this study 122,006 voluntary and replacement donations were screened for TTIs;HIV, HBV, HCV, Syphilis, Malaria and their seroprevalence was calculated. Further study was divided in Group “A” (from 2004 to 2008) and Group “B” (from 2009 to 2013) to compare the results. Results: Out of total 122,006 blood units collected, 79,750 (65.3%) were voluntary and 42,256 (34.7%) were replacement donors. The seropositivity of TTIs in the entire study, in group “A” and in Group “B” was 3.26% (3985/122,006) (p = 0.000005), 2.25% (1238/54,874) (p = 0.000005) and 4.09% (2747/67,123) (p = 0.000005) respectively. In Group “A” and “B” seroprevalence of HIV, HBV, HCV, Syphilis and Malaria was 0.29%, 1.16%, 0.61%, 0.06%, 0.11% and 0.13%, 3.15%, 0.24%, 0.17%, 0.03% respectively. Conclusion: Our study concluded that there was significant increase in seroprevalence of HBV and syphilis whereas decreasing pattern in HIV, HCV and Malaria was observed in last five years as compared to previous five years among the blood donors.

关键词： Transfusion transmitted Infections (TTIs) Blood Donor (BD) Human Immunodeficiency Virus (HIV) Hepatitis B Virus (HBV) Hepatitis C Virus (HCV) Syphilis and Malaria

Women and Sexually transmitted Infections in Africa

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Open Journal of Obstetrics and Gynecology 2015年第7期5卷 385-399页

作者： Gita Ramjee Nathlee S. Abbai Sarita Naidoo HIV Prevention Research Unit South African Medical Research Council Durban South Africa Department of Epidemiology and Population Health London School of Hygiene & Tropical Medicine London UK

Despite efforts to control the spread of sexually transmitted infections (STIs), these infections are still highly prevalent in the developing world, especially in Africa where the prevalence and incidence of Human immunodeficiency virus (HIV) is also very high. Unfortunately, women bear the disproportionate burden of both STIs and HIV in this region. Early diagnosis, treatment and prevention of STIs is therefore crucial in this population given the strong evidence that some STIs have been shown to facilitate the transmission of HIV. This review summarizes the epidemiology, and management of the common STIs affecting African women, and the health complications associated with these infections in the era of emerging antimicrobial resistance.

关键词： Women Sexually transmitted Infections Epidemiology Management Antimicrobial Resistance Human Immunodeficiency Virus

Perception of Sexually transmitted Infection-Preventive Measures among Senior Secondary School Students in Nnewi-North Local Government Area, Anambra State, Nigeria

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Open Journal of Preventive Medicine 2014年第9期4卷 708-716页

作者： Simeon Achunam Nwabueze Emmanuel Chukwunonye Azuike Chijioke Amara Ezenyeaku Clifford Chidiebere Aniagboso Ebele Dabeluchukwu Azuike Ifeoma Chisom Iloghalu Charles Chukwudalu Ebulue Uzoamaka Ugochinyere Epundu Obinna Francis Nwone Department of Community Medicine Nnamdi Azikiwe University Teaching Hospital Nnewi Nigeria Department of Nursing Sciences Faculty of Health Sciences Nnamdi Azikiwe University Awka Nigeria

Background: Sexually transmitted infections-preventive measures are effective methods employed in the prevention of sexually transmitted infections [STIs]. Sexually transmitted infections are among the most common infections in the world and therefore a major public health problem as they cause devastating long term consequences if untreated, especially in adolescents. Sexually transmitted infection-preventive measures, if correctly and consistently used, have been proven to be efficacious. Methodology: This was a cross-sectional descriptive study carried out among SS2 and SS3 students in Nnewi North Local Government Area of Anambra state, Nigeria. A structured, self administered questionnaire was administered to consenting senior secondary students to gather relevant information about socio-demogaraphic characteristics, knowledge about STIs, sexual behaviours. Three hundred and thirty four students participated in the study. Multi stage sampling technique was used. SPSS version 20 was used to analyze the data. Results were represented in tables and graphs. Results: Three hundred and thirty four students participated in the study, of which females and males are 167 each. 89% understood the meaning of STI. The majority of the respondents got the knowledge from TV/radio (34.4%), teachers (28.1%) and mother (27.0%). The majority of respondents knew that HIV/AIDS (89.8%), syphilis (58.1%) and Gonorrhoea (56.9%) were STIs. Good numbers of respondents knew the symptoms of STIs and risk factors of STI with unprotected sex and multiple sexual partners (57.5%) and (42.2%) respectively, as the highest risk factors. About 75.7% of respondents knew that HIV/AIDS cannot be cured. The Majority knew that avoiding sexual intercourse, being faithful to one partner and use of condom are preventive measures respectively. The majority of respondents (71%) felt they cannot be infected with an STI. 92.8% believed that STIs can be prevented. Age range for first sexual intercourse was 13 -

关键词： Knowledge Sexually transmitted Infections Preventive Measures Students

Impact of sexually transmitted infections on women health

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Health 2013年第8期5卷 1216-1226页

作者： Manisha Yadav Neha Verma Rakesh Singh Dhanda Department of Translational and Regenerative Medicine Post Graduate Institute of Medical Education & Research Chandigarh India Dr. B. R. Ambedkar Centre for Biomedical Research University of Delhi Delhi India

Sexually transmitted infections (STIs) are the infections that can be transmitted from one sex partner, who already has such infection, to another. The causes of STIs in human are very well elucidated and their causative agents are identified as bacteria, parasites and viruses. The worldwide epidemiology of more than 20 types of STIs has been established, which includes diseases like Chlamydia, Gonorrhea, Genital herpes, HIV/ AIDS, HPV, Syphilis and Trichomoniasis. Though STIs affect both men and women indiscriminately, however, the pathophysiology of disease is more obvious among women. Other than abstinence, the most effective way to prevent the transmission or acquisition of STIs is to use a condom during sexual intercourse. Condoms are effective in decreasing the transmission of HIV. However, once contacted, STIs caused by bacteria or parasites can be treated with antibiotics. STIs caused by a virus may not virtually have any cure though the medicines may keep the disease under control. Correct usage of preventive measures greatly reduces but does not completely eliminate the risk of catching or spreading STIs.

关键词： Sexually transmitted Infections Syphilis Gonorrhea Chlamydia Trichomonas Ge-nital Herpes HPV HIV

Water Resource, Hygienic Practice, and Soil transmitted Helminthiasis in Some Rural Communities of Osun State, Nigeria

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Journal of Water Resource and Protection 2017年第2期9卷 99-110页

作者： Tolulope Sunday Fafunwa Hammed Oladeji Mogaji Akinola Stephen Oluwole Abdulhakeem Adebiyi Adeniran Mariam Tobi Fagbenro Sammy Olufemi Sam-Wobo Babatunde Saheed Bada Uwem Friday Ekpo Department of Pure and Applied Zoology Federal University of Agriculture Abeokuta Nigeria Department of Animal and Environmental Biology Federal University Oye-Ekiti Oye-Ekiti Nigeria Department of Environmental Management and Toxicology Federal University of Agriculture Abeokuta Nigeria

Provision of water, sanitation and hygiene (WASH) resources has been advocated as necessary add-on strategy for sustainable control of soil-transmitted helminthiasis (STH) alongside annual mass drug administration (MDA) of albendazole to endemic communities. This study investigated the burden of STH and status of WASH resources in eight rural communities in Aiyedaade LGA, Osun State, Nigeria. Four of the communities were supported with improved water and hygiene resources (Category A), and another four supported only with improved water resources (Category B). Two hundred and sixteen (216) fresh stool samples were collected from consenting community members and screened for Ascaris lumbricoides, Hookworm and Trichuris trichiura infections using ether concentration method. The status and condition of WASH resources were determined using questionnaire and physical observation. An overall prevalence of 35.2% was observed for any STH infection. Species’ prevalence of Ascaris lumbricoides, Hookworm and Trichuris trichiura prevalence was 33.8%, 22.7%, and 0.5% respectively. Intensity of STH infection was significantly higher in Category A communities than in Category B communities. The prevalence of STH in Category A communities was higher (42.0%) than that in Category B communities (30.1%). There were significant differences (p = 0.000) in STH infections between the two categories. The status of improved water supply was not significantly different (p = 0.3153) in the two categories. Knowledge, attitude, and practices about STH, its transmission and control were low in both categories of communities. These results imply that current implementation of WASH which tends to focus on resource distribution, equity, and coverage, is unlikely to impact on STH transmission and control. Therefore, it is necessary for WASH providers to consider STH transmission control in their planning and implementation of WASH intervention for STH endemic communities.

关键词： Water Sanitation Hygiene Soil transmitted Helminthiasis Osun State Nigeria