Application of Optimization Techniques to Spectrally Modulated, Spectrally Encoded Waveform Design

A design process is demonstrated for a coexistent scenario containing Spectrally Modulated, Spectrally Encoded (SMSE) and Direct Sequence Spread Spectrum (DSSS) signals. Coexistent SMSE-DSSS designs are addressed under both perfect and imperfect DSSS code tracking conditions using a non-coherent delay-lock loop (DLL). Under both conditions, the number of SMSE subcarriers and subcarrier spacing are the optimization variables of interest. For perfect DLL code tracking conditions, the GA and RSM optimization processes are considered independently with the objective function being end-to-end DSSS bit error rate. A hybrid GA-RSM optimization process is used under more realistic imperfect DLL code tracking conditions. In this case, optimization is accomplished using a correlation degradation metric with the GA process being first applied to generate a “coarse” solution followed by RSM processing which provides the final optimized solution. This work has successfully expanded the practical utility of a previously developed tool, the original SMSE framework, by demonstrating a more efficient, structured means for coexistent waveform design that replaces previous trial and error methods

Characterizing a Leak in the HIV Care Cascade: Assessing Linkage Between HIV Testing and Care in Tanzania

Background: In Tanzania, HIV testing data are reported aggregately for national surveillance, making it difficult to accurately measure the extent to which newly diagnosed persons are entering care, which is a critical step of the HIV care cascade. We assess, at the individual level, linkage of newly diagnosed persons to HIV care. Methods: An expanded two-part referral form was developed to include additional variables and unique identifiers. The expanded form contained a corresponding number for matching the two-parts between testing and care. Data were prospectively collected at 16 health facilities in the Magu District of Tanzania. Results: The records of 1,275 unique people testing HIV positive were identified and included in our analysis. Of these, 1,200 (94.1%) responded on previous testing history, with 184 (15.3%) testing twice or more during the pilot, or having had a previous HIV positive test. Three-quarters (932; 73.1%) of persons were linked to care during the pilot timeframe. Health service provision in the facility carrying out the HIV test was the most important factor for linkage to care; poor linkage occurred in facilities where HIV care was not immediately available. Conclusions: It is critical for persons newly diagnosed with HIV to be linked to care in a timely manner to maximize treatment effectiveness. Our findings show it is feasible to measure linkage to care using routinely collected data arising from an amended national HIV referral form. Our results illustrate the importance of utilizing individual-level data for measuring linkage to care, as repeat testing is common

The Vehicle, Fall 2000

Vol. 42, No. 1 Table of Contents I Never Even Knew the Room NumberJeremy Hartzellpage 5 Charcoal Sketches of the MoonAlex Cardonapage 6 A Street, a Cat, the Sky, my Shoes, my Feet, TonightJanet Windeguthpage 7 Mainlining AmoreShanna Hullpage 9 Forest ChoirJeremy Hartzellpage 10 Ritual Timepiece ConfigurationsStella Linkpage 11 Carpe DiemRobb Dunnpage 12 Lost in AmericaTodd Beardpage 13 NeurastheniaBen Erwinpage 14 CowardVeronica Espinosapage 15 UntitledCarrie Smiglapage 16 When I Close My EyesJeremy Hartzellpage 17 Brigstaff ButterflyShanna Hullpage 18 Mice in the MotelRobb Dunnpage 19 The EscapeShanna Hullpage 21 RunningNicholas Janquartpage 29https://thekeep.eiu.edu/vehicle/1073/thumbnail.jp

The Vehicle, Fall 2000

Vol. 42, No. 1 Table of Contents I Never Even Knew the Room NumberJeremy Hartzellpage 5 Charcoal Sketches of the MoonAlex Cardonapage 6 A Street, a Cat, the Sky, my Shoes, my Feet, TonightJanet Windeguthpage 7 Mainlining AmoreShanna Hullpage 9 Forest ChoirJeremy Hartzellpage 10 Ritual Timepiece ConfigurationsStella Linkpage 11 Carpe DiemRobb Dunnpage 12 Lost in AmericaTodd Beardpage 13 NeurastheniaBen Erwinpage 14 CowardVeronica Espinosapage 15 UntitledCarrie Smiglapage 16 When I Close My EyesJeremy Hartzellpage 17 Brigstaff ButterflyShanna Hullpage 18 Mice in the MotelRobb Dunnpage 19 The EscapeShanna Hullpage 21 RunningNicholas Janquartpage 29https://thekeep.eiu.edu/vehicle/1073/thumbnail.jp

Alphavirus replicon-based enhancement of mucosal and systemic immunity is linked to the innate response generated by primary immunization

Venezuelan equine encephalitis virus replicon particles (VRP) function as an effective systemic, cellular and mucosal adjuvant when codelivered with antigen, and show promise for use as a component in new and existing human vaccine formulations. We show here that VRP are effective at low dose and by intramuscular delivery, two useful features for implementation of VRP as a vaccine adjuvant. In mice receiving a prime and boost with antigen, we found that VRP are required in prime only to produce a full adjuvant effect. This outcome indicates that the events triggered during prime with VRP are sufficient to establish the nature and magnitude of the immune response to a second exposure to antigen. Events induced by VRP in the draining lymph node after prime include robust secretion of many inflammatory cytokines, upregulation of CD69 on leukocytes, and increased cellularity, with a disproportionate increase of a cell population expressing CD11c, CD11b, and F4/80. We show that antigen delivered 24 hours after administration of VRP does not benefit from an adjuvant effect, indicating that the events which are critical to VRP-mediated adjuvant activity occur within the first 24 hours. Further studies of the events induced by VRP will help elucidate the mechanism of VRP adjuvant activity and will advance the safe implementation of this adjuvant in human vaccines

Enrollment in HIV Care and Treatment Clinic and Associated Factors Among HIV Diagnosed Patients in Magu District, Tanzania.

HIV care and treatment clinics (CTC) are important for management of HIV morbidity and mortality, and to reduce HIV transmission. Enrollment in HIV care and treatment clinics remains low in many developing countries. We followed up 632 newly diagnosed HIV patients aged 15 years and above from Magu District, Tanzania. Logistic regression was used to assess factors significantly associated with enrollment for CTC services. Kaplan-Meier plots and log-rank tests were used to evaluate differences in timing uptake of services. Among 632 participants, 214 (33.9%) were enrolled in CTC, and of those enrolled 120 (56.6%) took longer than 3 months to enroll. Those living in more rural villages were less likely to be enrolled than in the villages with semi-urban settings (OR 0.36; 95% CI 0.17-0.76). Moreover, those with age group 35-44 years and with age group 45 years and above were 2 times higher odds compared to those with age group 15-24 years, (OR 2.03; 95% CI 1.05-3.91) and (OR 2.69; 95% CI 1.40-5.18) respectively. Enrollment in the CTC in Tanzania is low. To increase uptake of antiretroviral therapy, it is critical to improve linkage between HIV testing and care services, and to rollout these services into the primary health facilities

Cascade of care for HIV-seroconverters in rural Tanzania: a longitudinal study.

We examined the HIV care cascade in a community-based cohort study in Kisesa, Magu, Tanzania. We analyzed the proportion achieving each stage of the cascade - Seroconversion, Awareness of HIV status, Enrollment in Care and Antiretroviral therapy (ART) initiation - and estimated the median and interquartile range for the time for progression to the next stage. Modified Poisson regression was used to estimate prevalence risk ratios for enrollment in care and initiation of ART. From 2006 to 2017, 175 HIV-seroconverters were identified. 140 (80%) knew their HIV status, of whom 97 (69.3%) were enrolled in HIV care, and 87 (49.7%) had initiated ART. Time from seroconversion to awareness of HIV status was 731.3 [475.5-1345.8] days. Time from awareness to enrollment was 7 [0-64] days, and from enrollment to ART initiation was 19 [3-248] days. There were no demographic differences in enrollment in care or ART initiation. Efforts have been focusing on shortening time from seroconversion to diagnosis, mostly by increasing the number of testing clinics available. We recommend increased systematic testing to reduce time from seroconversion to awareness of status, and by doing so speed up enrollment into care. Interventions that increase enrollment are likely to have the most impact in achieving UNAIDS targets

The prevalence and incidence of HIV in the ART era (2006-2016) in North West Tanzania.

BACKGROUND: Sub-Saharan countries bear a disproportionate percentage of HIV infections and HIV-related deaths despite the efforts to strengthen HIV prevention and treatments services, including ART. It is important to demonstrate how these services have contributed to reducing the epidemic using available population data. METHODS: We estimated the prevalence and incidence rates from a cohort running over 23 years in Magu District, Mwanza Region-North West Tanzania. Adults 15 years and over who were residents of the Kisesa observational HIV cohort study between 2006 and 2016 were eligible for inclusion. Survival analysis was used to calculate person-time at risk, incidence rates and 95% confidence intervals (CIs). Cox regression models were used for the risk factor analyses disaggregated by sex and age group. RESULTS: The HIV prevalence in the sero-surveys decreased from 7.2% in 2006/07 to 6.6% in 2016, with a notable decrease of over 50% for both men and women aged 15-24 years. The incidence rate for HIV was estimated to be 5.5 (95% CI 4.6-6.6) per 1,000 person-years in women compared to 4.6 (95% CI 3.5-5.8) in men, with a decrease over time. Despite the availability of ART services, the uptake is still small. CONCLUSIONS: New infections are still occurring, with high HIV incidence in individuals aged below 45 years. With new guidelines and the 95-95-95 UNAIDS target, prevalence and incidence must be adequately assessed. In addition, there is a need for additional efforts to assess the impact of HIV/AIDS prevention programmes and intervention services, especially in these areas where resources are limited

The classicism of Hugh Trevor-Roper

Hugh Trevor-Roper was educated as a classicist until he transferred to history, in which he made his reputation, after two years at Oxford. His schooling engendered in him a classicism that was characterised by a love of classical literature and style, but rested on a repudiation of the philological tradition in classical studies. This reaction helps to explain his change of intellectual career. His classicism, however, endured: it influenced his mature conception of the practice of historical studies, and can be traced throughout his life. This essay explores a neglected aspect of Trevor-Roper's intellectual biography through his ‘Apologia transfugae’ (1973), which explains his rationale for abandoning classics, and published and unpublished writings attesting to his classicism, especially his first publication ‘Homer unmasked!’ (1936) and his wartime notebooks

HIV-seroconversion among HIV-1 serodiscordant married couples in Tanzania: a cohort study.

BACKGROUND: Heterosexual transmission is the main driver of the HIV epidemic in Tanzania. Only one estimate of the incidence rate of intra-marital HIV seroconversion in Tanzania has been reported and was derived from data collected between 1991 and 1995. Moreover, little is known about the specific risk factors for intra-marital seroconversion in Tanzania. Improved evidence around factors that increase the risk of HIV transmission to a serodiscordant spouse is needed to develop and improve evidence-based interventions. We sought to investigate the rate of intra-marital HIV seroconversion among HIV sero-discordant couples in Tanzania as well as its associated risk factors. METHODS: We identified all HIV positive individuals in the TAZAMA HIV-serosurvey cohort and followed up their serodiscordant spouse from 2006 to 2016. The rate of seroconversion was analyzed by survival analysis using non-parametric regressions with exponential distribution. RESULTS: We found 105 serodiscordant couples, 14 of which had a seroconverting spouse. The overall HIV-1 incidence rate among spouses of people with HIV-1 infection was 38.0 per 1000 person/years [22.5-64.1]. Notably, the HIV-1 incidence rate among HIV-1 seronegative male spouses was 6.7[0.9-47.5] per 1000 person/years, compared to 59.3 [34.4-102.1] per 1000 person/years among female spouses. Sex of the serodiscordant spouse was the only significant variable, even after adjusting for other variables (Hazard rate = 8.86[1.16-67.70], p = 0.036). CONCLUSIONS: Our study suggests that rates of HIV-1 seroconversion of sero-discordant partners are much higher within marriage than in the general population in Tanzania. The major risk factor for HIV-1 seroconversion is sex of the serodiscordant spouse, with female spouses being at very high risk of acquiring HIV infection. This suggests that future programs that target serodiscordant couples could be a novel and effective means of preventing HIV-1 transmission in Tanzania