Soil structural degradation and nutrient limitations across land use categories and climatic zones in Southern Africa

Although soil degradation is a major threat to food security and carbon sequestration, our knowledge of the spatial extent of the problem and its drivers is very limited in Southern Africa. Therefore, this study aimed to quantify the risk of soil structural degradation and determine the variation in soil stoichiometry and nutrient limitations with land use categories (LUCs) and climatic zones. Using data on soil clay, silt, organic carbon (SOC), total nitrogen (N), available phosphorus (P), and sulfur (S) concentrations collected from 4,468 plots on 29 sites across Angola, Botswana, Malawi, Mozambique, Zambia and Zimbabwe, this study presents novel insights into the variations in soil structural degradation and nutrient limitations. The analysis revealed strikingly consistent stoichiometric coupling of total N, P, and S concentrations with SOC across LUCs. The only exception was on crop land where available P was decoupled from SOC. Across sample plots, the probability (φ) of severe soil structural degradation was 0.52. The probability of SOC concentrations falling below the critical value of 1.5% was 0.49. The probabilities of soil total N, available P, and S concentrations falling below their critical values were 0.95, 0.70, and 0.83, respectively. N limitation occurred with greater probability in woodland (φ = .99) and forestland (φ = .97) than in cropland (φ = .92) and grassland (φ = .90) soils. It is concluded that soil structural degradation, low SOC concentrations, and N and S limitations are widespread across Southern Africa. Therefore, significant changes in policies and practices in land management are needed to reverse the rate of soil structural degradation and increase soil carbon storage

Field Management of Anthracnose (Colletotrichum lindemuthianum) in Common Bean through Foliar Spray Fungicides and Seed Treatment Bioagents

Common bean anthracnose is a major production constraint in bean growing regions of Ethiopia. This study aimed to determine whether foliar sprays of mancozeb, folpan and mancolaxyl or antagonistic bioagents; Trichoderma harzianum, Trichoderma viride and Pseudomonas fluorescens could reduce anthracnose symptoms and consequently, increase yield and yield components. A total of seven treatments were arranged in a randomized complete block design with three replications. Statistical analysis showed significant differences among treatments. Anthracnose incidence, severity, infected pods per plant and the area under disease progress curve were highest in the control plots compared to the fungicide sprayed and bioagent treated seed plots. The highest percentage of infected pods per plant, 78.9 and 55 were recorded on the control and mancozeb sprayed plots respectively. The highest AUDPC value resulted in the lowest yield of 1.01 t/ha in the control plots compared to a highest yield of 3.33 t/ha from the sprayed plots with folpan and 1.79 t/ha from plots treated with Pseudomonas fluorescens. Relative yield losses of 69.67, 46.25 and 22.82% were recorded from the control, seed treated plots with P. fluorescens and sprayed plots with mancolaxyl respectively. Economic analysis revealed that the highest rate of return of 8,740 was obtained from Pseudomonas fluorescens seed treatment and the highest net benefit; 43,154 on folpan foliar spray treatment. The results of the present study support the novel possibility of using folpan foliar spray and Pseudomonas fluorescens seed treatments to decrease anthracnose symptoms in bean plants and consequently, achieve greater yield.Keywords: Bioagents; Folpan; Pseudomonas fluorescens; Mancolaxyl; seed treatmen

RHODOMYRTUS TOMENTOSA: A PHYTOCHEMICAL AND PHARMACOLOGICAL REVIEW

Rhodomyrtus tomentosa is a common wood, prevalent in areas with undemanding soil conditions and resistant toward pests and diseases. The plant can be found in China, Taiwan, Philippines, Malaysia, Indonesia, and Vietnam. Literature and artwork indicate that R. tomentosa played an important holistic role in the daily lives of several ancient cultures, providing medicinal benefits. R. tomentosa exhibits a wide spectrum of pharmacological effects and has been used to treat colic diarrhea, wounds, heartburn, abscesses, gynecopathy, and as a pain killer. R. tomentosa was used in traditional Chinese medicine to treat urinary tract infection. 42 compounds have been isolated from this plant and structurally elucidated. They comprise phloroglucinol, flavonoid, terpenoid, anthracene glycoside, tannin, and other compounds. Rhodomyrtone, a member of the acylphloroglucinols demonstrated a significant activity against a wide range of Gram-positive bacteria. Rhodomyrtone exhibited both antimicrobial and anti-infective activities. Several biological activities have been documented as antibacterial, antifungal, antimalarial, osteogenic, antioxidant, and anti-inflammatory. R. tomentosa has been studied extensively for alternative antimicrobial agents. Although rhodomyrtone exhibited potential activity with a very low minimum inhibitory concentration value, the mechanisms of action of this compound are still unclear. Furthermore, toxicity studies on it extract to validate pharmacological activities are required.Keywords: Rhodomyrtus tomentosa, Kemunting, Phytochemical, Pharmacological, Biological activities, Chemical constituents

Farmers’ ethno-ecological knowledge of vegetable pests and pesticidal plant use in Malawi and Zambia

While pests are a major constraint in vegetable production in many parts of Southern Africa, little is known about farmers’ knowledge and management practices. A survey was conducted among 168 and 91 vegetable farmers in Northern Malawi and Eastern Zambia, respectively, to evaluate their knowledge, attitudes and traditional management practices in tomato and crucifers (brassica). All respondents in Malawi and Zambia reported pest damage on tomato and crucifers, and 75% had used synthetic pesticides. The use of pesticidal plants, cultural practices and resistant varieties constituted a smaller portion of the pest control options in both crucifers and tomato. Over 70% of the respondents were aware of pesticidal plants, and more female (75%) than male (55%) respondents reported using them. While over 20 different plant species were mentioned by respondents, Tephrosia vogelii accounted for 61 and 53% of the pesticidal species known to respondents in Malawi and Zambia, respectively. Farmers with small landholdings were more inclined to use pesticidal plants than those with medium and large landholding highlighting the importance of this management alternative for poor farmers. Most respondents were willing to cultivate pesticidal plants, which indicate that farmers understand the potential value of these plants in pest management

Evaluation of Theoretical Frameworks to Detect Correlates of HPV Vaccination in the Midwest, US, Using Structural Equation Modeling

Knowledge of a valid, well-designed, and targeted theory-based framework helps better characterize reasons for HPV vaccine hesitancy and identify promising approaches to increase vaccination rates for eligible individuals. This study evaluated health theories in explaining factors affecting HPV vaccination and used a theoretical framework to identify direct and indirect predictors and mediators of HPV vaccination. A cross-sectional survey regarding HPV vaccine uptake and related factors was conducted among 1306 teenagers and young adults in the Midwest, US, in March and April 2023. Structural equation modeling confirmed fit of the framework based on the Integrated Health Theory (IHT) to the HPV vaccine data (Comparative Fit Index = 0.93; Tucker-Lewis Index = 0.92; Root Mean Square Error of Approximation = 0.053). While willingness to uptake the HPV vaccine directly predicted increased uptake (p \u3c 0.001), perceived benefits (p \u3c 0.001) and barriers (p \u3c 0.023) about the vaccine indirectly predicted increased and decreased uptake, respectively. In turn, beliefs about susceptibility (p = 0.005) and severity (p \u3c 0.001) of HPV infection and associated cancers and barriers to vaccination in general (p \u3c 0.001) indirectly predicted willingness to uptake the vaccine. In conclusion, IHT can be appropriate in examining predictors of HPV vaccine uptake in teenagers and young adults in the US, particularly in the Midwest

Mixed-effects height prediction model for Juniperus procera trees from a Dry Afromontane Forest in Ethiopia.

Tree height is a crucial variable in forestry science. In the current study, an accurate height prediction model for Juniperus procera Hochst. ex Endl. trees were developed, using a nonlinear mixed-effects modeling approach on 1215 observations from 101 randomly established plots in the Chilimo Dry Afromontane Forest in Ethiopia. After comparing 14 nonlinear models, the most appropriate base model was selected and expanded as a mixed-effects model, using the sample plot as a grouping factor, and adding stand-level variables to increase the model’s prediction ability. Using a completely independent dataset of observations, the best sampling alternative for calibration was determined using goodness-of-fit criteria. Our findings revealed that the Michaelis–Menten model outperformed the other models, while the expansion to the mixed-effects model significantly improved the height prediction. On the other hand, incorporating the quadratic mean diameter and the stem density slightly improved the model’s prediction ability. The fixed-effects of the selected model can also be used to predict the mean height of Juniperus procera trees as a marginal solution. The calibration response revealed that a systematic selection of the three largest-diameter trees at the plot level is the most effective for random effect estimation across new plots or stands

Molecular epidemiology of tuberculosis in the Somali region, eastern Ethiopia

Background: Tuberculosis (TB) is one of the leading causes of morbidity and mortality in low-income countries like Ethiopia. However, because of the limited laboratory infrastructure there is a shortage of comprehensive data on the genotypes of clinical isolates of Mycobacterium tuberculosis (M. tuberculosis) complex (MTBC) in peripheral regions of Ethiopia. The objective of this study was to characterize MTBC isolates in the Somali region of eastern Ethiopia. Methods: A cross-sectional study was conducted in three health institutions between October 2018 and December 2019 in the capital of Somali region. A total of 323 MTBC isolates (249 from pulmonary TB and 74 from extrapulmonary TB) were analyzed using regions of difference 9 (RD 9)-based polymerase chain reaction (PCR) and spoligotyping. Results: Of the 323 MTBC isolates, 99.7% (95% CI: 99.1-100%) were M. tuberculosis while the remaining one isolate was M. bovis based on RD 9-based PCR. Spoligotyping identified 71 spoligotype patterns; 61 shared types and 10 orphans. A majority of the isolates were grouped in shared types while the remaining grouped in orphans. The M. tuberculosis lineages identified in this study were lineage 1, 2, 3, 4, and 7 with the percentages of 7.4, 2.2, 28.2, 60.4, and 0.6%, respectively. Most (87.9%) of the isolates were classified in clustered spoligotypes while the remaining 12.1% isolates were singletons. The predominant clustered spoligotypes identified were SIT 149, SIT 21, SIT 26, SIT 53, and SIT 52, each consisting of 17.6, 13.3, 8.4, 7.4, and 5%, respectively. Lineage 3 and lineage 4, as well as the age group (15-24), were associated significantly with clustering. Conclusion: The MTBC isolated from TB patients in Somali region were highly diverse, with considerable spoligotype clustering which suggests active TB transmission. In addition, the Beijing spoligotype was isolated in relatively higher frequency than the frequencies of its isolation from the other regions of Ethiopia warranting the attention of the TB Control Program of the Somali region

Characteristics and outcomes of adult Ethiopian patients enrolled in HIV care and treatment: a multi-clinic observational study

Background: We describe trends in characteristics and outcomes among adults initiating HIV care and treatment in Ethiopia from 2006-2011. Methods: We conducted a retrospective longitudinal analysis of HIV-positive adults (≥15 years) enrolling at 56 Ethiopian health facilities from 2006–2011. We investigated trends over time in the proportion enrolling through provider-initiated counseling and testing (PITC), baseline CD4+ cell counts and WHO stage. Additionally, we assessed outcomes (recorded death, loss to follow-up (LTF), transfer, and total attrition (recorded death plus LTF)) before and after ART initiation. Kaplan-Meier techniques estimated cumulative incidence of these outcomes through 36 months after ART initiation. Factors associated with LTF and death after ART initiation were estimated using Hazard Ratios accounting for within-clinic correlation. Results: 93,418 adults enrolled into HIV care; 53,300 (57%) initiated ART. The proportion enrolled through PITC increased from 27.6% (2006–2007) to 44.8% (2010–2011) (p < .0001). Concurrently, median enrollment CD4+ cell count increased from 158 to 208 cells/mm3 (p < .0001), and patients initiating ART with advanced WHO stage decreased from 56.6% (stage III) and 15.0% (IV) in 2006–2007 to 47.6% (stage III) and 8.5% (IV) in 2010–2011. Median CD4+ cell count at ART initiation remained stable over time. 24% of patients were LTF before ART initiation. Among those initiating ART, attrition was 30% after 36 months, with most occurring within the first 6 months. Recorded death after ART initiation was 6.4% and 9.2% at 6 and 36 months, respectively, and decreased over time. Younger age, male gender, never being married, no formal education, low CD4+ cell count, and advanced WHO stage were associated with increased LTF. Recorded death was lower among younger adults, females, married individuals, those with higher CD4+ cell counts and lower WHO stage at ART initiation. Conclusions: Over time, enrollment in HIV care through outpatient PITC increased and patients enrolled into HIV care at earlier disease stages across all HIV testing points. However, median CD4+ cell count at ART initiation remained steady. Pre- and post-ART attrition (particularly in the first 6 months) have remained major challenges in ensuring prompt ART initiation and retention on ART