Longitudinal and spatial analysis of Americans' travel distances following COVID-19.

Travel has become less common due to COVID-19. While prior research has discussed recent travel changes for Americans in multiple ways, few have examined the adjusted travel that has been sustained since March 2021. In addition, little is known about changes in Americans' travel patterns in trips by distance.

Image sequence interpolation based on optical flow, segmentation, and optimal control.

When using motion fields to interpolate between two consecutive images in an image sequence, a major problem is to handle occlusions and disclusions properly. However, in most cases, one of both images contains the information that is either discluded or occluded; if the first image contains the information (i.e.

Incidence of HIV, hepatitis C and hepatitis B viruses among injection drug users in southwestern China: a 3-year follow-up study.

Objective: To investigate the incidence rates of HIV, hepatitis C virus (HCV), and hepatitis B virus (HBV) among injection drug users (IDU) in a drug trafficking city in southwest China.

Design: A prospective cohort study.

Methods: A cohort of 333 HIV-seronegative IDU was followed for 36 months from November 2002 and evaluated every 6 months for seroconversions to HIV and HCV antibodies as well as hepatitis B surface antigen.

[Factors associated with retention in a community-based methadone maintenance treatment among heroin addicts].

Objective: To explore factors associated with retention in a community-based methadone maintenance treatment (MMT) among heroin addicts in Xichang of Sichuan province.

Methods: All 206 heroin addicts were first admitted to MMT community-based program between March to September 2004. Baseline data of patients characteristics, social function, drug using behaviors, sexual behaviors, dose of methadone and retention were collected.

Impact of methadone on drug use and risky sex in China.

This study examined the impact of methadone on drug-using and risky sexual behaviors among 557 heroin injection drug users in one of the first methadone programs in China. Structured questionnaires were administered to collect data on methadone utilization, drug use, and risky sexual behaviors. Blood samples were tested for blood-borne infections.

Nonfatal overdose among heroin users in southwestern China.

Objective: To evaluate the prevalence of and risk factors for nonfatal overdose among heroin users in southwestern China.

Methods: In 2005, 731 heroin users in Sichuan Province, China were interviewed for overdose experiences in the past 12 months. Factors hypothesized to be associated with overdose were evaluated with logistic regression models.

[Incidence rates of human immunodeficiency virus and syphilis as well as the rate of retention in a 6-month follow-up study of female sex workers in areas with heavy drug use in Xichang of Sichuan province, China].

Objective: To investigate the human immunodeficiency virus (HIV) and syphilis incidence rates as well as the retention rate in a cohort with 6-month follow-up study among female sex workers (FSWs).

Methods: From December, 2004, to January, 2005, a community-based baseline survey was conducted to recruit 343 FSWs for a prospective cohort study in Xichang county of Sichuan province, China. Follow-up visits were conducted at 6 months to analyze risk factors associated with cohort retention for subjects' baseline sociodemographic and sexual behavioral characteristics.

Continued spread of HIV among injecting drug users in southern Sichuan Province, China.

Objective: To estimate HIV prevalence among injecting drug users (IDUs) in a drug trafficking city in southwest Sichuan Province, China.

Methods: A total of 314 IDUs was invited to participate in the cross-sectional survey in 2004 through community outreach recruitment and peer referrals. Blood sample was taken for HIV antibody testing and a structured questionnaire was administered to collect information on socio-demographics, drug using and sexual behaviors.

[A prospective cohort study on human immunodeficiency virus and syphilis seroconversion among injecting drug users].

Objective: To study the rate of human immunodeficiency virus (HIV) seroconversion, HIV transmission and related risk factors among injecting drug users (IDUs) in an area of Sichuan province.

Methods: In November 2002, a community-based baseline survey was conducted to recruit 333 HIV-seronegative IDUs for a prospective cohort study in Xichang county of Sichuan province, China. Follow-up visits were carried out every 6 months to study the situation of drug use, sexual behaviors of the IDUs and blood specimens were collected to test for antibodies against HIV and syphilis.

Syphilis among female sex workers in southwestern China: potential for HIV transmission.

Objective: The objective of this study was to investigate the prevalence and risk factors of syphilis infection among female sex workers in a southwestern Chinese city along a drug trafficking route.

Methods: From December 2004 to January 2005, 343 female sex workers (FSWs) were recruited through community outreach and peer referring. Confidential questionnaire interviews were administered to collect information on sexual and other sexually transmitted diseases/HIV risk behaviors.

[Single nucleotide polymorphisms of HIV coreceptor CCR5 gene in Chinese Yi ethnic group and its association with HIV infection].

Objective: To investigate the single nucleotide polymorphism (SNP) of HIV-1 coreceptor CCR5 gene in Chinese Yi ethnic group and the association between these SNPs and HIV/AIDS.

Methods: Peripheral blood samples of 102 HIV negative persons of Chinese Yi nationality, 87 males amd 15 females, aged 23 (12-37), and 68 HIV carriers, 61 males and 7 females, aged 27 (17-51). The regulatory and structural regions of the HIV coreceptor CCR5 gene were amplified from the genomic DNA by nested PCR, each of the two regions was divided into three gene fragments which were overlapped.

Gender and HIV risk behavior among intravenous drug users in Sichuan Province, China.

Using data from a community-based study of injection drug users (IDUs) in Sichuan Province in China, this study compared the level of HIV risk behavior (needle sharing and unsafe sex) amongst female and male IDUs, and examined the risk factors separately for these two groups. Five risk factors were examined in the analysis, including a lack of family support, having an IDU primary sex partner, economic pressure, lack of access to a methadone program, and younger age. Regression results showed that male and female IDUs had different risk factors.

HIV incidence and factors contributed to retention in a 12-month follow-up study of injection drug users in Sichuan Province, China.

HIV-1 seroconversion and subtype were evaluated, and factors associated with cohort retention were analyzed for subjects' baseline sociodemographic and behavioral characteristics in a 12-month follow-up study of injection drug users (IDUs). In November 2002, a community-based baseline survey was conducted to recruit 333 HIV-seronegative IDUs for a prospective cohort study in Xichang County of Sichuan Province, China. During the 12-month follow-up period, HIV incidence was 3.

[Community-based survey on human immunodeficiency virus infection among injection drug users in Sichuan, China].

Objective: To investigate prevalence of human immunodeficiency virus (HIV) infection and risk factors for its transmission among injection drug users (IDUs) in Liangshan Yizu Autonomous Prefecture of Sichuan Province, China.

Methods: A community-based survey was conducted to investigate demographic characteristics, pattern and frequency of sharing injection equipment, and sexual behaviors in IDUs. Blood samples were also collected from them to detect for antibodies against HIV and syphilis.

Community-based survey of HIV transmission modes among intravenous drug users in Sichuan, China.

Goal: The goal of this study was to investigate the prevalence and different transmission risk factors of HIV among intravenous drug users (IDUs) in the Liangshan Yizu Autonomous Region of Sichuan province, China.

Methods: From November 8, 2002, to November 29, 2002, a community-based survey was conducted to investigate demographic characteristics, sharing patterns of injection equipment, frequencies of injection equipment, and sexual behaviors in IDUs. Blood samples were also collected to test for HIV and syphilis infection.

Community-based survey of HCV and HIV coinfection in injection drug abusers in Sichuan Province of China.

Aim: To investigate the prevalence and risk factors of HCV/HIV coinfection in injection drug abusers (IDAs) in Lianshan Yi Autonomous Prefecture of Sichuan province, China.

Methods: From November 8, 2002 to November 29, 2002, a community-based survey was conducted to investigate the demographic characteristics, patterns of shared injectors devices and sexual behaviors in IDAs. Blood samples were also collected to test HCV and HIV infection.