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The radio spectral energy distribution and star formation calibration in MIGHTEECOSMOS highly star-forming galaxies at 1.5
(Institute of Physics, 2025) Jarvis, Matt; Taylor, Russ; Whittam, Imogen H; An, Fangxia; Vaccari, Mattia
Studying the radio spectral energy distribution (SED) of distant galaxies is essential for understanding their assembly and evolution over cosmic time. We present rest-frame radio SEDs of a sample of 160 star-forming galaxies at 1.5 < z < 3.5 in the Cosmic Evolution Survey field as part of the MeerKAT International GHz Tiered Extragalactic Exploration project. MeerKAT observations combined with archival Very Large Array and Giant Metrewave Radio Telescope data allow us to determine the integrated mid-radio (ν = 1–10 GHz) continuum (MRC) luminosity and magnetic field strength. A Bayesian method is used to model the SEDs and to separate the free–free and synchrotron emission. We also calibrate the star formation rate (SFR) in radio both directly through SED analysis and indirectly through the infrared–radio correlation (IRRC). With a mean value of αnt ≃ 0.7, the synchrotron spectral index flattens with both redshift and specific SFR, indicating that cosmic rays are more energetic in the early Universe due to higher star formation activity. The magnetic field strength increases with redshift, B ∝ (1 + z) (0.7±0.1) , and SFR as B ∝ SFR0.3, suggesting a small-scale dynamo acting as its main amplification mechanism. Taking into account the evolution of the SEDs, the IRRC is redshift invariant, and it does not change with stellar mass at 1.5 < z < 3.5, although the correlation deviates from linearity. Similarly, we show that the SFR traced using the integrated MRC luminosity is redshift invariant.
Evaluating satellite-derived evapotranspiration estimates against ground-based measurements in arid upper orange catchment, South Africa
(Taylor and Francis Ltd., 2026) Dube , Timothy; Maxala , Boitumelo; Maswanganye , Eugene
Evapotranspiration (ET) accounts for ~60% of surface water loss, and accurate estimation is vital for water management in arid regions. This study assessed ET in the Upper Orange catchment, South Africa, using the surface energy balance system (SEBS), Penman–Monteith (PM) and MODIS 16 against eddy covariance (EC) flux tower data. Landsat 8 and MODIS were analyzed for eight days in 2020. Model accuracy was evaluated using RMSE, Pbias and R², while ANOVA was used to test differences across land cover types. SEBS showed the highest accuracy (RMSE = 2.48 mm/day, R² = 0.71), outperforming MODIS (RMSE = 3.21 mm/day, R² = 0.59), while PM performed moderately well (RMSE = 2.85 mm/day, R² = 0.66). Both SEBS and PM overestimated ET by 25%–33%. ANOVA confirmed significant land cover differences (p = 0.04), with grasslands recording the highest ET. Overall, SEBS provided robust and spatially reliable estimates, offering valuable insights for water accounting and policy development
Effect of sowing date and genotype on pearl millet yield across semi-arid regions of Sub-Saharan Africa
(John Wiley and Sons Inc, 2026) Dube , Timothy; Awala , Simon; Niipele , Johanna
In climate change–vulnerable, food-insecure semi-arid regions of Sub-Saharan Africa, limited studies compared the performance of pearl millet [Pennisetum glaucum (L.)] landraces and improved genotypes under staggered sowing to establish their interactions, resulting in a generalization that landraces are lower yielding than their improved counterparts. A 3-year field experiment was conducted to compare grain and biomass production of an improved Okashana-2 and the landrace Kantana pearl millet genotypes under five sowing dates between January 1 and March 1 in semi-arid North-Central Namibia. Across years, Kantana sown on January 1 produced the highest grain and shoot biomass yields, ranging from 0.5 to 9.5 t ha−1 and 2.6 to 31.4 t ha−1, respectively, with both gradually declining with sowing delays. Higher grain and biomass yields in early-sown Kantana were due to its longer vegetative growth phase, nearly 2 weeks longer than that of its Okashana-2 counterpart, allowing more time for normal growth and development before heading. Okashana-2, on the other hand, attained its highest yields under January 1 or January 15 sowing dates, with grain and biomass yields ranging from 0.8 to 7.4 t ha−1 and 1.7 to 18.6 t ha−1, respectively, fluctuating among sowing dates; however, March 1 sowing produced the lowest yields. The variable yields for Okashana-2 indicate the genotype’s ability to respond rapidly to soil moisture from various rainfall events. These results demonstrate that maximum pearl millet yields in northern Namibia are achievable by sowing Kantana by January 1, while Okashana-2 has higher and relatively stable yields under late sowing. However, farmers must promptly acquire production inputs and services to facilitate early sowing
A conductive metal-organic framework-modified electrode for sensitive electrochemiluminescent detection of cardiac Troponin I
(Elsevier Ltd., 2026) Baker , Priscilla; Murray , Alenzo; Valenti , Giovanni
The design of a sensitive and accurate electrochemiluminescence (ECL) immunosensor for the early detection of cardiac biomarkers at low concentrations is essential to improve patient outcomes. In this study, a conductive metal-organic framework (c-MOF), Cu3(HHTP)2, was drop-coated onto a screen-printed carbon electrode (SPCE) to produce an ultra-efficient electrochemical sensing platform which was subsequently functionalized with cTnI antibodies (Ab) and bovine serum albumin (BSA) for selective detection of the cardiac Troponin I. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) confirmed the successful stepwise fabrication of the immunosensor. We investigated the ECL behaviour of the Cu3(HHTP)2-modified SPCE using [Ru(bpy)3]2+ as the luminophore and found that a significant increase in ECL intensity was achieved compared to that of the unmodified SPCE. This enhancement was attributed to the high conductivity, porous structure, the increased surface area of the c-MOF and crucially the HHTP ligand plays a critical role in enabling ECL generation in this system. The analytical performance of the immunosensor was evaluated by monitoring the ECL responses at varying cTnI concentrations. The immunosensor achieved a detection limit of 10.23 ± 1.06 pg/mL in vitro, well below the clinically relevant cTnI thresholds, highlighting its potential for rapid and early-stage cardiac biomarker detection. These findings suggest the Cu3(HHTP)2-based ECL immunosensor represents a viable sensing platform that significantly increases conductivity and ECL efficiency without the need of additional coreactant species.
Mediators in the effect of maternal alcohol consumption and cigarette smoking on cardiometabolic risk factors in 10–14-year-old adolescents
(Springer Nature, 2026) Hartel, Tammy; Oelofse, André; De Smidt, Juléy
Aim To identify potential mediators of the development of cardiometabolic risk factors in adolescents exposed to cigarette smoking and alcohol in utero. Methods A total of 307 adolescents aged 10–14 years who were enrolled in urban schools in Cape Town, South Africa, were evaluated. Anthropometric measurements, lipid profiles and blood pressure measurements were obtained from 307 adolescents aged 10–14 years in a low-socioeconomic community. Statistical analysis included nonparametric tests, as most of the data were not normally distributed. Mediation analyses were conducted via linear regression and the PROCESS Macros models. Results Maternal cigarette smoking during pregnancy had a significant direct effect on childhood SBP after adjusting for covariates. However, the indirect effect of BMI on SBP was significant, suggesting a 1-unit increase in BMI leading to a 1.38 mmHg increase in SBP. In addition, BW was not associated with adolescent SBP. Moreover, adolescent BMI mediated the effect of maternal cigarette smoking on overweight/obesity, rather than the direct effect of maternal cigarette smoking. Additionally, BW was significantly and positively associated with BMI but not with adolescent overweight/obesity in this cohort. Maternal smoking was also directly associated with low HDL cholesterol in boys only. Conclusion BMI was identified as the main mediator in the effect of maternal smoking on adolescent SBP, overweight and obesity. Moreover, in utero exposure was not significantly associated with higher BMI or higher BP measurements, obesity or overweight. Cardiometabolic risk in terms of higher BMI/overweight and obesity was lower than those with no exposure