Prediction of Persistence of Fertilizer-derived Cadmium in Oregon Agricultural Soils using Equilibrium Modeling and Fertilizer Release Kinetics

Organic farming has become a multimillion dollar industry and while much emphasis is put on subsequent fertilizer inputs onto these fields, very little consideration is given to the prior fertilization activities of these soils. For a farm to be certified organic it means no harmful chemicals have been applied for at least three years. The overall hypothesis tested by this research was that equilibrium adsorption models can adequately represent the behavior of fertilizer-derived cadmium in Oregon agricultural soils and that such model results can be easily incorporated into risk assessment models, transport study models and persistence studies for organic or other sustainable farming considerations. Soil chemistry and soil characterization were used to calculate the doubling time and mass flux of cadmium-derived fertilizer in loamy and sandy agricultural soils with a rich farming history. We also investigated the processes controlling the release of fertilizer-derived cadmium in the micro scale zone around the fertilizer to determine if a local equilibrium model was appropriate for explaining cadmium behavior in agricultural soils. The Kd values and adsorption trend of the soil sites was Pendleton \u3e Klamath \u3e Hyslop \u3e Hermiston. The cadmium Kd values were most correlated to the pH of the soils (R2=0.94). The buffer capacity of the soils was highly correlated to the clay content (R2 = 0.98). The adsorption coefficients were important for predicting the doubling times of cadmium in the soils (Hermiston, 4.8yrs \u3e Hyslop, 3.7yrs \u3e Klamath, 2.9 yrs\u3e Pendleton 2.3 yrs). Precipitation was not the most important parameter in predicting the mass loss due to leaching after three years (46.2, 19.9, 16.7 and 8.3 mg/ha-yr for Hyslop, Hermiston, Pendleton and Klamath respectively). The period was found to have a negligible effect on the background concentrations of cadmium in agricultural soils. Scanning electron microscopy, X-ray diffraction and column displacement experiments were used to investigate the fertilizer kinetics of fertilizer-derived cadmium and the processes controlling the release of fertilizer-derived cadmium were found to be a Cd-phosphate phase, possibly cadmium hydroxyapaptite, and iron oxides. The release of Cd from phosphate fertilizer was slow so a local equilibrium model was appropriate for agricultural soils

Bilateral HIV related ocular surface squamous neoplasia: a paradigm shift

A CAJM research article on HIV related ocular surface squamous neoplasia at an eye unit hospital in Zimbabwe.Four patients with bilateral ocular surface squamous neoplasia attended to at Sekuru Kaguvi Hospital Eye Unit are being presented to alert practitioners that OSSN is potentially a bilateral disease and its prevalence is likely to increase as the life expectancy of HIV infected patients is being positively affected by antiretroviral therapy. Reports on ocular diseases should be clear on laterality to avoid confusion between number of patients affected and number of eyes involved since the two cannot be used interchangeably

Aggregate roads maintenance and cost: case study of state of Minnesota

Researchers investigated the methods and costs of maintaining and upgrading aggregate roads. The goals were to estimate the cost of routine maintenance, re-graveling, and resurfacing, and to develop a process to justify upgrading the road to a paved surface when appropriate. By reviewing maintenance activities in different counties it may be possible to identify which factors affect maintenance costs. With this knowledge, it would be possible to more effectively predict gravel road maintenance costs. This thesis discusses gravel road design requirements; material used on the roadway; and maintenance guidelines and activities based on a review of The Army Corp of Engineers, FHWA and South Dakota, State of Maine, Washington State, USDA Forest Services, and Australia Road Research Board aggregate road design and maintenance rules and regulations. Also provided is a review of the state of Minnesota\u27s aggregate road maintenance costs and activities based on seven visited counties: Waseca County, Olmstead County, Blue Earth County, Benton County, Meeker County, Aitkin County and Kandiyohi County. The researchers reviewed these counties\u27 maintenance activities, including smoothing surface, minor surface repair, snow and ice removal, reshaping, resurfacing, and dust treatments so as to identify their effect on the total aggregate road maintenance cost. In addition, a cost comparison was performed to investigate differences in costs among counties and by differences in the Average Annual Daily Traffic on aggregate road maintenance cost/mile. This research was sponsored by the Minnesota Local Research Board through the Minnesota Department of Transportation

Biochar production and applications in sub-Saharan Africa: Opportunities, constraints, risks and uncertainties

Sub-Saharan Africa (SSA) experiences soil degradation, food and livelihood insecurity, environmental pollution and lack of access to energy. Biochar has gained international research attention, but few studies have investigated the potential of biochar to address the challenges in SSA. This paper seeks to identify and evaluate generic potential opportunities and constraints associated with biochar application in sub-Saharan Africa using Zimbabwe as case study. Specific objectives were to; (1) identify and quantify feedstocks for biochar production; (2) review literature on the biochar properties, and evaluate its potential applications in agriculture, environmental remediation and energy provision, and (3) identify research gaps, risks and constraints associated with biochar technology. Biochar feedstocks in Zimbabwe were estimated to be 9.9 Mt yr⁻¹, predominantly derived from manure (88%) and firewood (10%). This will yield 3.5, 1.7 and 3.1 Mt yr⁻¹ of biochar, bio-oil and synthetic gas, respectively. Land application of the 3.5 Mt yr⁻¹ of biochar (≈63% C) would sequester approximately 2.2 Mt yr⁻¹ of soil carbon in Zimbabwe alone, while simultaneously minimizing the environmental and public health risks, and greenhouse gas emissions associated with solid organic wastes. Biochar potentially enhances soil and crop productivity through enhanced nutrient and soil moisture availability, amelioration of acidic soils and stimulation of microbial diversity and activity. Due to its excellent adsorption properties, biochar has potential applications in industrial and environmental applications including water and wastewater treatment, remediation and revegetation of contaminated soils and water. Biochar products have energy values comparable or higher than those of traditional biomass fuels; thereby making them ideal alternative sources of energy especially for poor households without access to electricity. Before the benefits of biochar can be realized in SSA, there is need to overcome multiple risks and constraints such as lack of finance, socio-economic constraints including negative perceptions and attitudes among both researchers and consumers, and environmental and public health risks. Therefore, there is need to conduct fundamental research to demonstrate the benefits of biochar applications, and develop policy framework and criteria for its production and subsequent adoption.Keywords: Energy provision, Carbon sequestration, Smallholder agroecosystems, Zimbabwe, Climate change, Pyrolysis, Biochar, Crop productivit

Study Protocol: The Simulated Ocular Surgery (SOS) Trials: Randomised-Controlled Trials Comparing Intense Simulation-Based Surgical Education for Cataract and Glaucoma Surgery to Conventional Training Alone in East and Southern Africa

There is a huge need to perform high volumes of surgery in sub-Saharan Africa, to tackle the backlog of avoidable blindness. There is a great need to train many eye surgeons safely, efficiently, effectively, and to an acceptable level of competence. There is also a need to maintain and improve the quality and outcomes of surgery. Currently, surgical training is often conducted using the traditional "apprentice model", where a trainee observes a qualified surgeon and learns from them, and then the surgeon supervises the trainee performing surgery on a patient. We believe that this conventional model has substantial limitations and drawbacks, making surgical training less efficient and less safe. We will test the hypothesis that intense modular simulation-based ophthalmic surgical education is superior to conventional training for the initial acquisition of competence. Pilot studies have been conducted in Malawi, Uganda, and South Africa to develop, test and refine aspects of modular simulation-based ophthalmic surgical training in cataract and glaucoma surgery. Assessment tools have been developed and validated for use in this simulation-based training (see Appendices 3a and 3b). Subsequent to these pilot and validation studies, we are now able to test the efficacy of focussed modular simulation-based ophthalmic surgical training in two separate parallel-group randomised controlled trials. We will conduct two independent trials of intense simulation-based ophthalmic surgical education for training ophthalmologists in the procedures for cataract, and separately for glaucoma: the two leading causes of blindness in sub-Saharan Africa. Trainee eye surgeons will be randomised to the 'intervention' of focussed simulation-based surgical training (in addition to, and as an enhancement to conventional training), or to the 'control' group of current conventional training alone. The 'control' group participants will receive the same simulation training, only after a period of one year. Follow-up assessments will measure whether the trainees have gained in surgical competence (objectively assessed using a specific and validated grading score), knowledge, their perceived confidence as a surgeon, and in terms of the benefit to their patients (the quality and quantity of surgery performed). All the training within the 'educational intervention' of this study will be performed using simulation. There is no testing or surgical training on patients within the study educational-intervention of both training trials. The only times when patients are indirectly involved is entirely as part of standard, regulated, and supervised clinical training within a Nationally accredited and registered ophthalmology training programme. When three anonymised and non-identifiable recordings of cataract surgical procedures are video-recorded (at three months, year one, and then another three at fifteen months), patients will be informed of the planned recording, and invited to sign a standardised informed consent as for any clinical image recording within standard clinical practice. Live surgery recordings or assessments for the GLASS trial intervention and control groups will be conducted in individual circumstances where the local Consultant Ophthalmologist deems the participant competent to perform (and record) SUPERVISED live surgery during the year post-intervention

Intense Simulation-Based Surgical Education for Manual Small-Incision Cataract Surgery: The Ophthalmic Learning and Improvement Initiative in Cataract Surgery Randomized Clinical Trial in Kenya, Tanzania, Uganda, and Zimbabwe.

Importance: Cataracts account for 40% of cases of blindness globally, with surgery the only treatment. Objective: To determine whether adding simulation-based cataract surgical training to conventional training results in improved acquisition of surgical skills among trainees. Design, Setting, and Participants: A multicenter, investigator-masked, parallel-group, randomized clinical educational-intervention trial was conducted at 5 university hospital training institutions in Kenya, Tanzania, Uganda, and Zimbabwe from October 1, 2017, to September 30, 2019, with a follow-up of 15 months. Fifty-two trainee ophthalmologists were assessed for eligibility (required no prior cataract surgery as primary surgeon); 50 were recruited and randomized. Those assessing outcomes of surgical competency were masked to group assignment. Analysis was performed on an intention-to-treat basis. Interventions: The intervention group received a 5-day simulation-based cataract surgical training course, in addition to standard surgical training. The control group received standard training only, without a placebo intervention; however, those in the control group received the intervention training after the initial 12-month follow-up period. Main Outcomes and Measures: The primary outcome measure was overall surgical competency at 3 months, which was assessed with a validated competency assessment rubric. Secondary outcomes included surgical competence at 1 year and quantity and outcomes (including visual acuity and posterior capsule rupture) of cataract surgical procedures performed during a 1-year period. Results: Among the 50 participants (26 women [52.0%]; mean [SD] age, 32.3 [4.6] years), 25 were randomized to the intervention group, and 25 were randomized to the control group, with 1 dropout. Forty-nine participants were included in the final intention-to-treat analysis. Baseline characteristics were balanced. The participants in the intervention group had higher scores at 3 months compared with the participants in the control group, after adjusting for baseline assessment rubric score. The participants in the intervention group were estimated to have scores 16.6 points (out of 40) higher (95% CI, 14.4-18.7; P < .001) at 3 months than the participants in the control group. The participants in the intervention group performed a mean of 21.5 cataract surgical procedures in the year after the training, while the participants in the control group performed a mean of 8.5 cataract surgical procedures (mean difference, 13.0; 95% CI, 3.9-22.2; P < .001). Posterior capsule rupture rates (an important complication) were 7.8% (42 of 537) for the intervention group and 26.6% (54 of 203) for the control group (difference, 18.8%; 95% CI, 12.3%-25.3%; P < .001). Conclusions and Relevance: This randomized clinical trial provides evidence that intense simulation-based cataract surgical education facilitates the rapid acquisition of surgical competence and maximizes patient safety. Trial Registration: Pan-African Clinical Trial Registry, number PACTR201803002159198

Experiences and Perceptions of Ophthalmic Simulation-Based Surgical Education in Sub-Saharan Africa.

BACKGROUND: Simulation-based surgical education (SBSE) can positively impact trainee surgical competence. However, a detailed qualitative study of the role of simulation in ophthalmic surgical education has not previously been conducted. OBJECTIVE: To explore the experiences of trainee ophthalmologists and ophthalmic surgeon educators' use of simulation, and the perceived challenges in surgical training. METHODS: A multi-center, multi-country qualitative study was conducted between October 2017 and August 2020. Trainee ophthalmologists from six training centers in sub-Saharan Africa (SSA) (in Kenya, Uganda, Tanzania, Zimbabwe and South Africa) participated in semi-structured interviews, before and after an intense simulation training course in intraocular surgery. Semi-structured interviews were also conducted with experienced ophthalmic surgeon educators. Interviews were anonymized, recorded, transcribed and coded. An inductive, bottom-up, constant comparative method was used for thematic analysis. RESULTS: Twenty-seven trainee ophthalmologists and 12 ophthalmic surgeon educators were included in the study and interviewed. The benefits and challenges of conventional surgical teaching, attributes of surgical educators, value of simulation in training and barriers to implementing ophthalmic surgical simulation were identified as major themes. Almost all trainees and trainers reported patient safety, a calm environment, the possibility of repetitive practice, and facilitation of reflective learning as beneficial aspects of ophthalmic SBSE. Perceived barriers in surgical training included a lack of surgical cases, poor supervision and limited simulation facilities. CONCLUSIONS: Simulation is perceived as an important and valuable model for education amongst trainees and ophthalmic surgeon educators in SSA. Advocating for the expansion and integration of educationally robust simulation surgical skills centers may improve the delivery of ophthalmic surgical education throughout SSA

Implementing prevention policies for mother-to-child transmission of HIV in rural Malawi, South Africa and United Republic of Tanzania, 2013-2016.

OBJECTIVE: To assess adoption of World Health Organization (WHO) guidance into national policies for prevention of mother-to-child transmission (PMTCT) of human immunodeficiency virus (HIV) and to monitor implementation of guidelines at facility level in rural Malawi, South Africa and the United Republic of Tanzania. METHODS: We summarized national PMTCT policies and WHO guidance for 15 indicators across the cascades of maternal and infant care over 2013-2016. Two survey rounds were conducted (2013-2015 and 2015-2016) in 46 health facilities serving five health and demographic surveillance system populations. We administered structured questionnaires to facility managers to describe service delivery. We report the proportions of facilities implementing each indicator and the frequency and durations of stock-outs of supplies, by site and survey round. FINDINGS: In all countries, national policies influencing the maternal and infant PMTCT cascade of care aligned with WHO guidelines by 2016; most inter-country policy variations concerned linkage to routine HIV care. The proportion of facilities delivering post-test counselling, same-day antiretroviral therapy (ART) initiation, antenatal care and ART provision in the same building, and Option B+ increased or remained at 100% in all sites. Progress in implementing policies on infant diagnosis and treatment varied across sites. Stock-outs of HIV test kits or antiretroviral drugs in the past year declined overall, but were reported by at least one facility per site in both rounds. CONCLUSION: Progress has been made in implementing PMTCT policy in these settings. However, persistent gaps across the infant cascade of care and supply-chain challenges, risk undermining infant HIV elimination goals

Simulation-based surgical education for glaucoma versus conventional training alone: the GLAucoma Simulated Surgery (GLASS) trial. A multicentre, multicountry, randomised controlled, investigator-masked educational intervention efficacy trial in Kenya, South Africa, Tanzania, Uganda and Zimbabwe.

BACKGROUND/AIM: Glaucoma accounts for 8% of global blindness and surgery remains an important treatment. We aimed to determine the impact of adding simulation-based surgical education for glaucoma. METHODS: We designed a randomised controlled, parallel-group trial. Those assessing outcomes were masked to group assignment. Fifty-one trainee ophthalmologists from six university training institutions in sub-Saharan Africa were enrolled by inclusion criteria of having performed no surgical trabeculectomies and were randomised. Those randomised to the control group received no placebo intervention, but received the training intervention after the initial 12-month follow-up period. The intervention was an intense simulation-based surgical training course over 1 week. The primary outcome measure was overall simulation surgical competency at 3 months. RESULTS: Twenty-five were assigned to the intervention group and 26 to the control group, with 2 dropouts from the intervention group. Forty-nine were included in the final intention-to-treat analysis. Surgical competence at baseline was comparable between the arms. This increased to 30.4 (76.1%) and 9.8 (24.4%) for the intervention and the control group, respectively, 3 months after the training intervention for the intervention group, a difference of 20.6 points (95% CI 18.3 to 22.9, p<0.001). At 1 year, the mean surgical competency score of the intervention arm participants was 28.6 (71.5%), compared with 11.6 (29.0%) for the control (difference 17.0, 95% CI 14.8 to 19.4, p<0.001). CONCLUSION: These results support the pursuit of financial, advocacy and research investments to establish simulation surgery training units and courses including instruction, feedback, deliberate practice and reflection with outcome measurement to enable trainee glaucoma surgeons to engage in intense simulation training for glaucoma surgery. TRIAL REGISTRATION NUMBER: PACTR201803002159198