B831: The Role of Human Capital in the Adoption of Conservation Tillage: The Case of Aroostook County, Maine, Potato Farmers

Given the continuing potential loss from soil erosion and the significant effort put forth recently to alleviate the problem in Aroostook County, it is important to study ways to improve the success rate of that effort. One way to improve the soil loss problem is for farmers to adopt conservation tillage practices for those areas where there are significant benefits from doing so. The objective of this study is to identify the characteristics important in the adoption decisions of Aroostook County farmers. The Maine results will be compared with results from a study in Iowa to identify any differences in the decisionmaking process in Maine relative to Iowa.https://digitalcommons.library.umaine.edu/aes_bulletin/1021/thumbnail.jp

Sexual behaviour among persons living with HIV/AIDS in Kampala, Uganda

Objective:  Design: Setting: Results:  Conclusions:  This study demonstrates that abstinence and use of condoms on their own may not be enough for HIV prevention among PLWHAs who desire children. Additional methods such as use of ART to reduce HIV infectiousness and sperm washing are needed.In the past 12 months 227 (60%) of the PLWHAs were sexually active. Of the sexually active 42 (19%) never used a condom, and 92 (40%) used condoms inconsistently, thus 134 (35%) of PLWHAs engaged in high risk sex. Two hundred and sixty five (70%) said that PLWHAs can have healthy children and 115 (30%) desired more children with 21 (10%) of the women in the reproductive age group reporting a pregnancy and 22 (17%) of the men reporting having caused a pregnancy. Only three (7%) of the pregnancies were unplanned. Desire for more children was a strong independent predictor of engaging in high risk sex (Adjusted Odds Ratio 2.44, 95% CI 1.35-4.42).Joint Clinical Research Centre, Kampala Uganda. Participants: Three hundred and eighty PLWHAs, 50% of whom had initiated antiretro viral therapy (ART). Main outcome measures: PLWHAs answered questions regarding sexual behaviour, number and type of sexual partners, symptoms of sexually transmitted infections, having been pregnant or causing a pregnancy, social demographic characteristics, consumption of alcohol, having biological children, desire for more children and use of condoms.A cross sectional study.To identify sexual behaviour and reproductive health needs of people living with HIV/AIDS (PLWHAs)

A noninvasive method for quantifying cerebral blood flow by hybrid PET/MRI

Although PET with 15O-water is the gold standard for imaging cerebral blood flow (CBF), quantification requires measuring the arterial input function (AIF), which is an invasive and noisy procedure. To circumvent this problem, we propose a noninvasive PET/MRI approach that eliminates the need to measure AIF by using global CBF determined by phase-contrast (PC) MRI as a reference region. This approach not only is noninvasive but also involves no additional imaging time, because PC MRI and 15O-water PET are acquired simultaneously. The purpose of this study was to test the accuracy of this hybrid method in an animal model in which AIF was measured directly and CBF was varied by changing the arterial CO2 tension. Methods: PET and MRI data were simultaneously acquired in juvenile pigs at hypocapnia (n 5 5), normocapnia (n 5 5), and hypercapnia (n 5 4). CBF was measured by the MRI reference method and by PET alone using an MRI-compatible blood sampling system to measure AIF. Results: Global CBF estimates from PC MRI and 15O-water PET agreed well, with a correlation coefficient of 0.9 and a slope of 0.88. Strong positive correlations (R2 . 0.96) were also found between regional CBF generated by the PET-only and the MRI-reference methods. Conclusion: These findings demonstrate the accuracy of this hybrid PET/MRI approach, which might prove useful in patients for whom obtaining accurate CBF measurements is challenging

Mapping long-term functional changes in cerebral blood flow by arterial spin labeling

Although arterial spin labeling (ASL) is appealing for mapping long-term changes in functional activity, inter-sessional variations in basal blood flow, arterial transit times (ATTs), and alignment errors, can result in significant false activation when comparing images from separate sessions. By taking steps to reduce these sources of noise, this study assessed the ability of ASL to detect functional CBF changes between sessions. ASL data were collected in three sessions to image ATT, resting CBF and CBF changes associated with motor activation (7 participants). Activation maps were generated using rest and task images acquired in the same session and from sessions separated by up to a month. Good agreement was found when comparing between-session activation maps to within-session activation maps with only a 16% decrease in precision (within-session: 90 ± 7%) and a 13% decrease in the Dice similarity (within-session: 0.75 ± 0.07) coefficient after a month. In addition, voxel-wise reproducibility (within-session: 4.7 ± 4.5%) and reliability (within-session: 0.89 ± 0.20) of resting grey-matter CBF decreased by less than 18% for the betweensession analysis relative to within-session values. ATT variability between sessions (5.0 ± 2.7%) was roughly half the between-subject variability, indicating that its effects on longitudinal CBF were minimal. These results demonstrate that conducting voxel-wise analysis on CBF images acquired on different days is feasible with only modest loss in precision, highlighting the potential of ASL for longitudinal studies

Impaired cerebrovascular function in coronary artery disease patients and recovery following cardiac rehabilitation

© 2016 Anazodo, Shoemaker, Suskin, Ssali, Wang and St. Lawrence. Coronary artery disease (CAD) poses a risk to the cerebrovascular function of older adults and has been linked to impaired cognitive abilities. Using magnetic resonance perfusion imaging, we investigated changes in resting cerebral blood flow (CBF) and cerebrovascular reactivity (CVR) to hypercapnia in 34 CAD patients and 21 age-matched controls. Gray matter volume (GMV)s were acquired and used as a confounding variable to separate changes in structure from function. Compared to healthy controls, CAD patients demonstrated reduced CBF in the superior frontal, anterior cingulate (AC), insular, pre- and post-central gyri, middle temporal, and superior temporal regions. Subsequent analysis of these regions demonstrated decreased CVR in the AC, insula, post-central and superior frontal regions. Except in the superior frontal and precentral regions, regional reductions in CBF and CVR were identified in brain areas where no detectable reductions in GMV were observed, demonstrating that these vascular changes were independent of brain atrophy. Because aerobic fitness training can improve brain function, potential changes in regional CBF were investigated in the CAD patients after completion of a 6-months exercise-based cardiac rehabilitation program. Increased CBF was observed in the bilateral AC, as well as recovery of CBF in the dorsal aspect of the right AC, where the magnitude of increased CBF was roughly equal to the reduction in CBF at baseline compared to controls. These exercise-related improvements in CBF in the AC is intriguing given the role of this area in cognitive processing and regulation of cardiovascular autonomic control

Contextual, structural, and mental health experiences of children of women engaged in high-risk sexual behaviour in Kampala: a mixed method study

Children born to women who sell sex for money or commodities may face economic and social insecurity because of their mother’s work, particularly in settings where sex work is illegal. From October 2020 to May 2021, we conducted a study with 60 children aged 12–24 years, born to sex workers in Kampala, Uganda. The children took part in 60 semi-structured interviews, 20 life history interviews, and 4 focus group discussions, which were used to explore their social, economic, and mental health experiences and investigate their vulnerabilities and resilience. Quantitative data were collected using REDcap, and descriptive analysis was done using Stata 14. Qualitative data were collected using semi-structured topic guides, and data analysed thematically. We explored findings in relation to a wellbeing framework. The findings showed that children experienced contextual and structural hardships, including incomplete and irregular schooling, a lack of privacy at home, food insecurity, and physical and psychological violence from relatives and sometimes from their mothers. Some children reported mental wellbeing struggles with hopelessness, nervousness, and sadness. Alcohol and drug use were common in most families. Community social network support systems, including neighbours and grandparents, were important; most children had absentee fathers. Some children suspected or knew how their mother earned her income. Resilience for most children was tagged to support from close networks and financial support from the government and civil society. Children of sex workers in Kampala experience structural, contextual, and mental health challenges but have a positive attitude towards the future. It is important to strengthen community support systems for these children and those living in similar circumstances in low- and middle-income countries

Feasibility of simultaneous whole-brain imaging on an integrated PET-MRI system using an enhanced 2-point Dixon attenuation correction method.

PURPOSE: To evaluate a potential approach for improved attenuation correction (AC) of PET in simultaneous PET and MRI brain imaging, a straightforward approach that adds bone information missing on Dixon AC was explored. METHODS: Bone information derived from individual T1-weighted MRI data using segmentation tools in SPM8, were added to the standard Dixon AC map. Percent relative difference between PET reconstructed with Dixon+bone and with Dixon AC maps were compared across brain regions of 13 oncology patients. The clinical potential of the improved Dixon AC was investigated by comparing relative perfusion (rCBF) measured with arterial spin labeling to relative glucose uptake (rPETdxbone) measured simultaneously with (18)F-flurodexoyglucose in several regions across the brain. RESULTS: A gradual increase in PET signal from center to the edge of the brain was observed in PET reconstructed with Dixon+bone. A 5-20% reduction in regional PET signals were observed in data corrected with standard Dixon AC maps. These regional underestimations of PET were either reduced or removed when Dixon+bone AC was applied. The mean relative correlation coefficient between rCBF and rPETdxbone was r = 0.53 (p \u3c 0.001). Marked regional variations in rCBF-to-rPET correlation were observed, with the highest associations in the caudate and cingulate and the lowest in limbic structures. All findings were well matched to observations from previous studies conducted with PET data reconstructed with computed tomography derived AC maps. CONCLUSION: Adding bone information derived from T1-weighted MRI to Dixon AC maps can improve underestimation of PET activity in hybrid PET-MRI neuroimaging

Frequency and impact of suboptimal immune recovery on first-line antiretroviral therapy within the International Epidemiologic Databases to Evaluate AIDS in East Africa

OBJECTIVE: To describe patterns of suboptimal immune recovery (SO-IR) and associated HIV-related-illnesses during the first 5 years following first-line antiretroviral therapy (ART) initiation across seven ART sites in East Africa. DESIGN: Retrospective analysis of data from seven ART clinical sites (three Uganda, two Kenya and two Tanzania). METHODS: SO-IR was described by proportions of ART-treated adults with CD4 cell counts less than 200, less than 350 and less than 500 cells/μl. Kaplan-Meier survival analysis techniques were used to assess predictors of SO-IR, and incident rates of HIV-related illnesses at CD4 cell counts less than 200, 200-350, 351-499, and >500 cells/μl, respectively. RESULTS: Overall 80 843 adults initiated non-nucleoside reverse transcriptase inhibitor-based first-line ART; 65% were women and median CD4 cell count was 126 [interquartile range (IQR), 52-202] cells/μl. Cumulative probability of SO-IR <200 cells/μl, <350 cells/μl and <500 cells/μl, after 5 years, was 11, 38 and 63%, respectively. Incidence of HIV-related illnesses was higher among those with CD4 cell counts less than 200 and 200-350 cells/μl, than those who achieved CD4 counts above these thresholds. The most common events, at CD4 < 200 cells/μl, were pulmonary tuberculosis [incident rate 15.98 (15.47-16.51)/100 person-years at risk (PYAR), oral candidiasis [incident rate 12.5 (12.03-12.94)] and herpes zoster [incident rate 6.30 (5.99-6.64)] events/100 PYAR. With attainment of a CD4 cell count level 200-350 cells/μl, there was a substantial reduction in events/100 PYAR - by 91% to 1.45 (1.29-1.63) for TB, by 94% to 0.75 (0.64-0.89) for oral candidiasis, by 84% to 0.99 (0.86-1.14) for Herpes Zoster, and by 78% to 1.22 (1.07-1.39) for chronic diarrhea. The incidence of all events decreased further with CD4 counts above these thresholds. CONCLUSION: Around 40% of adults initiated on ART have suboptimal immune recovery with CD4 counts <350 cells/μl after five years. Such patients will require closer monitoring for both HIV-related and non-HIV-related clinical events

Six-Month Mortality among HIV-Infected Adults Presenting for Antiretroviral Therapy with Unexplained Weight Loss, Chronic Fever or Chronic Diarrhea in Malawi.

In sub-Saharan Africa, early mortality is high following initiation of antiretroviral therapy (ART). We investigated 6-month outcomes and factors associated with mortality in HIV-infected adults being assessed for ART initiation and presenting with weight loss, chronic fever or diarrhea, and with negative TB sputum microscopy

The Lived Experience Of Participants in an African RandomiseD trial (LEOPARD): protocol for an in-depth qualitative study within a multisite randomised controlled trial for HIV-associated cryptococcal meningitis.

INTRODUCTION: Individuals recruited into clinical trials for life-threatening illnesses are particularly vulnerable. This is especially true in low-income settings. The decision to enrol may be influenced by existing inequalities, poor healthcare infrastructure and fear of death. Where patients are confused or unconscious the responsibility for this decision falls to relatives. This qualitative study is nested in the ongoing AMBIsome Therapy Induction OptimisatioN (AMBITION) Trial. AMBITION is recruiting participants from five countries in sub-Saharan Africa and is trialling a novel treatment approach for HIV-associated cryptococcal meningitis, an infection known to affect brain function. We aim to learn from the experiences of participants, relatives and researchers involved in AMBITION. METHODS AND ANALYSIS: We will collect data through in-depth interviews with trial participants and the next of kin of participants who were confused at enrolment and therefore provided surrogate consent. Data will be collected in Gaborone, Botswana; Kampala, Uganda and Harare, Zimbabwe. Interviews will follow a narrative approach including participatory drawing of participation timelines. This will be supplemented by direct observation of the research process at each of the three recruiting hospitals. Interviews will also take place with researchers from the African and European institutions that form the partnership through which the trial is administered. Interviews will be transcribed verbatim, translated (if necessary) and organised thematically for narrative analysis. ETHICS AND DISSEMINATION: This study has been approved by the Health Research Development Committee, Gaborone (Reference: HPDME:13/18/1); Makerere School of Health Sciences Institutional Review Board, Kampala (Reference: 2019-061); University of Zimbabwe Joint Research Ethics Committee, Harare (Reference: 219/19), and the London School of Hygiene and Tropical Medicine (Reference: 17957). Study findings will be shared with research participants from the sites, key stakeholders at each research institution and ministries of health to help inform the development and implementation of future trials. The findings of this study will be published in journals and presented at academic meetings. TRIAL REGISTRATION: Registered at www.clinicaltrials.gov:NCT04296292