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The existence of missing geomagnetic reversals has been proposed, with potential for new magnetostratigraphic age controls. We estimate geomagnetic reversal frequency from 0 to 155 Ma using adaptive‐bandwidth kernel density estimation (AKDE) to evaluate data sparseness and to assess how reversal frequency changes when recently identified geomagnetic reversals are incorporated into the geomagnetic polarity time scale (GPTS) data set. AKDE is a two‐stage procedure that uses an initial density estimator based on an initial (pilot) bandwidth. We found that the pilot bandwidth determined using cross‐validation is stable with respect to data set length. The AKDE results obtained based on the cross‐validated pilot bandwidth reveal four troughs after the Cretaceous Normal Superchron, spaced 13.5–15.0 Myr apart and corresponding to relatively long chrons (>0.8 Myr). One trough near 32 Ma becomes less distinct after the four recently identified reversals are added to the data set. This sensitivity suggests that troughs in the frequency curve may indicate missing geomagnetic reversals.

The Ethiopia‐Yemen flood basalts are spatially zoned with progressively lower TiO2 lavas from near the Afar depression toward the margins. The timing and rate of emplacement of low TiO2 (LT) lavas are poorly known compared with the ultra‐high TiO2 (HT2) lavas. We measured two high‐precision 40Ar/39Ar ages of 29.63 ± 0.14 and 30.02 ± 0.22 Ma (2σ) from basalts of the 2‐km‐thick LT lava sequence at the Afar plume head margin. Using our eruption age model constructed from our and previous 40Ar/39Ar ages with the paleomagnetic directions, we estimate that the LT lava eruption continued over Chrons C12r‐C12n‐C11r. The eruption of the plume head margin started earlier than the plume head axis emplacement in C12n. Also, the eruption rate was low at the margin, high at the axis. We estimate that the LT lavas are induced by the edge‐driven convection, the result of a plume‐lithosphere interaction, not a plume head. Plain Language Summary The Ethiopia‐Yemen Flood Basalts are thought to be the expression of a mantle plume erupting millions of km3 of basaltic lava in a geologically short period (1–3 million years [Myr]). Titanium concentrations in the flood basalts are zoned and named HT2, HT1, and LT basalts (from high to low Ti). The eruption timing and rate of the HT2 basalts are constrained with high precision, but those of the LT basalts remain ambiguous. Therefore, we measured two high‐precision 40Ar/39Ar ages from LT basalts in the 2‐km‐thick Lima‐Limo section, which erupted northwest of the Afar area. Based on our eruption age model constructed from 40Ar/39Ar ages and paleomagnetic directions, we estimate that the eruption of the LT basalts started earlier than the HT2 basalts that erupted in Chron C12n and lasted over at most ∼2 Myr. The eruptive rate of the LT basalts in the earliest interval was lower than that of the HT2 basalts. This feature of the eruption may be explained by edge‐driven convection caused by the interaction of a gradient of the lithospheric thickness with the Afar mantle plume. Key Points We obtained two new 40Ar/39Ar ages for the low‐Ti basalt from the Lima‐Limo section of the Ethiopia–Yemen flood basalts Based on our eruptive age model, we correlated the Lima‐Limo section to Chrons C12r to C11r We concluded that the non‐plume low‐Ti basalts erupted before the Afar plume high‐Ti basalts because of the plume–lithosphere interaction

The Ethiopia‐Yemen flood basalts are spatially zoned with progressively lower TiO 2 lavas from near the Afar depression toward the margins. The timing and rate of emplacement of low TiO 2 (LT) lavas are poorly known compared with the ultra‐high TiO 2 (HT2) lavas. We measured two high‐precision 40 Ar/ 39 Ar ages of 29.63 ± 0.14 and 30.02 ± 0.22 Ma (2σ) from basalts of the 2‐km‐thick LT lava sequence at the Afar plume head margin. Using our eruption age model constructed from our and previous 40 Ar/ 39 Ar ages with the paleomagnetic directions, we estimate that the LT lava eruption continued over Chrons C12r‐C12n‐C11r. The eruption of the plume head margin started earlier than the plume head axis emplacement in C12n. Also, the eruption rate was low at the margin, high at the axis. We estimate that the LT lavas are induced by the edge‐driven convection, the result of a plume‐lithosphere interaction, not a plume head. The Ethiopia‐Yemen Flood Basalts are thought to be the expression of a mantle plume erupting millions of km 3 of basaltic lava in a geologically short period (1–3 million years [Myr]). Titanium concentrations in the flood basalts are zoned and named HT2, HT1, and LT basalts (from high to low Ti). The eruption timing and rate of the HT2 basalts are constrained with high precision, but those of the LT basalts remain ambiguous. Therefore, we measured two high‐precision 40 Ar/ 39 Ar ages from LT basalts in the 2‐km‐thick Lima‐Limo section, which erupted northwest of the Afar area. Based on our eruption age model constructed from 40 Ar/ 39 Ar ages and paleomagnetic directions, we estimate that the eruption of the LT basalts started earlier than the HT2 basalts that erupted in Chron C12n and lasted over at most ∼2 Myr. The eruptive rate of the LT basalts in the earliest interval was lower than that of the HT2 basalts. This feature of the eruption may be explained by edge‐driven convection caused by the interaction of a gradient of the lithospheric thickness with the Afar mantle plume. We obtained two new 40 Ar/ 39 Ar ages for the low‐Ti basalt from the Lima‐Limo section of the Ethiopia–Yemen flood basalts Based on our eruptive age model, we correlated the Lima‐Limo section to Chrons C12r to C11r We concluded that the non‐plume low‐Ti basalts erupted before the Afar plume high‐Ti basalts because of the plume–lithosphere interaction

Rifts and rifted margins form when continents break apart and shape the continent-to-ocean transition on much of our planet. The sedimentary basins that result from continental rifting host unique sedimentary archives of palaeo-environmental and palaeo-climatic change required to understand complex natural processes. Rifts and rifted margins are key sites for natural resources (e.g. geothermal and hydrogen potential, critical metal resources, and CO2 storage) and have an important societal relevance in the mitigation of geohazards such as earthquakes and volcanic activity. However, knowledge on the tectonic structure, sedimentary architecture, rapid palaeo-environmental change, fluid flow and hydrothermal circulation, deep subsurface biosphere, and their impacts on biogeochemical fluxes in rift basins remains poorly understood. Considering their large scientific potential and societal relevance, understanding the formation and architecture of rifts and rifted margins is now critical. The Afar rift is a world-class natural field lab where continental breakup can be directly observed. The northern part of Afar, the Danakil Depression, especially represents a unique snapshot in space and time when the continent ruptures and new seafloor and adjacent rifted margins form. However, deep subsurface records are missing in the basin. The ADD-ON project aims at deep drilling in the Danakil Depression to provide a unique sedimentary record in an active rift basin paced by global environmental fluctuations and their interplay with volcanic and tectonic events. To explore drilling targets and address scientific drilling objectives, an International Continental Scientific Drilling Program (ICDP) workshop was organized in Addis Ababa, Ethiopia, in August 2023. In total, 64 participants from 10 countries and all career stages respecting diversity and inclusion joined the workshop. They represented a wide range of scientific disciplines including government agencies, industry, local universities, and communities to discuss the overall ADD-ON science plan during several workshop sessions. One target drilling site has been flagged, covering the unique Pleistocene full syn-rift sedimentary record in the Danakil Depression. This unique sedimentary archive will allow us to (1) unravel complex palaeo-environmental change in a rift basin, (2) understand incipient and intermittent dynamics through punctuated volcano-tectonic events in a rift transitioning from continental rifting towards seafloor spreading and adjacent rifted margin development, (3) test the origin and limits of life in the deep biosphere under poly-extreme conditions, (4) better understand fluid flow and fluid–sediment interaction in an active hydrothermal system, and (5) use the drilling site to develop a downhole Earth observatory to improve hazard-related monitoring capacity (earthquakes, gas/fluid flux, ground motion).

This thesis represents a study of partially parallel imaging and active passive shielding with the goal of making MRI faster and quieter. We present the design and optimization of rectangular surface rf coils used for partially parallel imaging. The effect of passive copper shielding applied to the outside of an actively shielded gradient is studied with the aim of substantially reducing induced eddy currents in the cryostat inner bore. A ladder rf coil design with all-neighbors coupling included is considered. First, it is shown that, due to far-neighbor couplings, exact decoupling and degeneracy of normal modes are impossible. A technique for minimizing the frequency spread by appropriate choice of capacitors is investigated. A special surface coil design with an additional “parasitic” loop is considered. This coil is shown to have four exact degenerate normal modes. The theoretical predictions are compared with experimental results. A g-factor calculation of two and four rectangular surface coils is considered. It is shown that g-factors can be minimized by changing the relative orientation of the coils. A new regularization technique for SENSE image reconstruction is considered. This technique requires no prior knowledge of the likelihood of the image. Our numerical simulations applied to simulated data acquired with a four-element phased array coils and reduction factor (R = 4) show that there is a reasonable trade-off between signal and aliasing for a given weighting factor. Two configurations of passive shielding are analyzed. The first uses a cylindrical copper cover applied to the outside gradient assembly circumference, and the second extends the copper over the ends of the gradient assembly. For a z-gradient, a 2mm thick copper layer on the gradient circumference reduces the power deposited in the cryostat inner bore by 26.7dB for 1kHz harmonic gradient excitation. Extending the passive shield to cover the ends of the gradient reduces cryostat inner bore power deposition by more than 22dB for the same frequency. For a transverse gradient a finite element calculation shows that a 2mm copper shield without end caps reduces the eddy currents on the cryostat inner bore by a factor of 30 at the same frequency.

Durum wheat is an important cereal grown in Ethiopia, a country which is also its center for genetic diversity. Yellow (stripe) rust caused by Puccinia striiformis fsp tritici is one of the most devastating diseases threatening Ethiopian wheat production. To identify sources of genetic resistance and combat this pathogen, we conducted a genome wide association study of yellow rust resistance on 300 durum wheat accessions comprising 261 landraces and 39 cultivars. The accessions were evaluated for their field resistance using a modified Cobb scale at Meraro, Kulumsa and Chefe Donsa in the 2015 and 2016 main growing seasons. Analysis of the 35K Axiom Array genotyping data of the panel resulted in a total of 8,797 polymorphic SNPs of which 7,093 were used in subsequent analyses. Population structure analysis suggested two groups in which the cultivars clearly stood out separately from the landraces. Eleven SNPs significantly associated with yellow rust resistance were identified on four chromosomes (1A, 1B, 2B, and 5A) which defined at least five genomic loci. Six of the SNPs were consistently identified on chromosome 1B singly at each and combined overall environments which explained 62.6–64.0% of the phenotypic variation (R 2 ). Resistant allele frequency ranged from 14.0–71.0%; Zooming in to the identified resistance loci revealed the presence of disease resistance related genes involved in the plant defense system such as the ABC transporter gene family, disease resistance protein RPM1 (NBS-LRR class), Receptor kinases and Protein kinases. This study has provided SNPs for tracking the loci associated with yellow rust resistance and a diversity panel which can be used for association study of other agriculturally important traits in durum wheat.

Semantic, technical, content, criterion and conceptual equivalence must be examined in order to validate a psychological rating scale in a new cultural setting. Few validation studies have been conducted in sub-Saharan Africa for scales seeking to detect depression in pregnant women. The aim of this study is to validate the 9-item Patient Health Questionnaire (PHQ-9) as a screening instrument for depression among Afaan Oromo speaking pregnant Ethiopian women. A random sample of 246 pregnant women were recruited in Seka Chekorsa District, Ethiopia during their first, second or third trimester. One week later, 29 participants were selected to answer the questionnaire for a second time to evaluate test retest reliability. The Mini International Neuropsychiatric Interview (MINI-Plus) scale was used as a gold standard to evaluate validity. PHQ-9 was compared with MINI-Plus and sensitivity, specificity, accuracy, positive likelihood ratio, negative likelihood ratio and Receiver Operating Characteristic Curves (ROC) for PHQ-9 were calculated. Rasch analysis was also carried out using Winsteps version 3.81.0. The reliability coefficient, Cronbach's alpha, for the PHQ-9 total score was 0.84. Both the agreement and consistency Intra-class Correlation coefficients (ICC) for the one-week test-retest reliability were 0.98. The cut-off point of a summed score of eight resulted in a sensitivity of 80.8% and a specificity of 79.5%. The calculated area under the curve (AUC) for the PHQ-9 score versus the MINI-Plus was excellent, 0.88 (SE = 0.04; CI = 0.81-0.95). The PHQ-9 meets the criteria established by Linacre for rating scale effectiveness. The PHQ-9 proved to be a reliable and valid instrument that may be used to screen major depressive disorders among Afaan Oromo speaking Ethiopian pregnant women.

Previous Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) studies have reported national health estimates for Ethiopia. Substantial regional variations in socioeconomic status, population, demography, and access to health care within Ethiopia require comparable estimates at the subnational level. The GBD 2019 Ethiopia subnational analysis aimed to measure the progress and disparities in health across nine regions and two chartered cities. We gathered 1057 distinct data sources for Ethiopia and all regions and cities that included census, demographic surveillance, household surveys, disease registry, health service use, disease notifications, and other data for this analysis. Using all available data sources, we estimated the Socio-demographic Index (SDI), total fertility rate (TFR), life expectancy, years of life lost, years lived with disability, disability-adjusted life-years, and risk-factor-attributable health loss with 95% uncertainty intervals (UIs) for Ethiopia's nine regions and two chartered cities from 1990 to 2019. Spatiotemporal Gaussian process regression, cause of death ensemble model, Bayesian meta-regression tool, DisMod-MR 2.1, and other models were used to generate fertility, mortality, cause of death, and disability rates. The risk factor attribution estimations followed the general framework established for comparative risk assessment. The SDI steadily improved in all regions and cities from 1990 to 2019, yet the disparity between the highest and lowest SDI increased by 54% during that period. The TFR declined from 6·91 (95% UI 6·59–7·20) in 1990 to 4·43 (4·01–4·92) in 2019, but the magnitude of decline also varied substantially among regions and cities. In 2019, TFR ranged from 6·41 (5·96–6·86) in Somali to 1·50 (1·26–1·80) in Addis Ababa. Life expectancy improved in Ethiopia by 21·93 years (21·79–22·07), from 46·91 years (45·71–48·11) in 1990 to 68·84 years (67·51–70·18) in 2019. Addis Ababa had the highest life expectancy at 70·86 years (68·91–72·65) in 2019; Afar and Benishangul-Gumuz had the lowest at 63·74 years (61·53–66·01) for Afar and 64.28 (61.99-66.63) for Benishangul-Gumuz. The overall increases in life expectancy were driven by declines in under-5 mortality and mortality from common infectious diseases, nutritional deficiency, and war and conflict. In 2019, the age-standardised all-cause death rate was the highest in Afar at 1353·38 per 100 000 population (1195·69–1526·19). The leading causes of premature mortality for all sexes in Ethiopia in 2019 were neonatal disorders, diarrhoeal diseases, lower respiratory infections, tuberculosis, stroke, HIV/AIDS, ischaemic heart disease, cirrhosis, congenital defects, and diabetes. With high SDIs and life expectancy for all sexes, Addis Ababa, Dire Dawa, and Harari had low rates of premature mortality from the five leading causes, whereas regions with low SDIs and life expectancy for all sexes (Afar and Somali) had high rates of premature mortality from the leading causes. In 2019, child and maternal malnutrition; unsafe water, sanitation, and handwashing; air pollution; high systolic blood pressure; alcohol use; and high fasting plasma glucose were the leading risk factors for health loss across regions and cities. There were substantial improvements in health over the past three decades across regions and chartered cities in Ethiopia. However, the progress, measured in SDI, life expectancy, TFR, premature mortality, disability, and risk factors, was not uniform. Federal and regional health policy makers should match strategies, resources, and interventions to disease burden and risk factors across regions and cities to achieve national and regional plans, Sustainable Development Goals, and universal health coverage targets. Bill & Melinda Gates Foundation.

ObjectiveThe aim of this study was to provide a comprehensive evidence on risk factors for transmission, disease severity and COVID-19 related deaths in Africa.DesignA systematic review has been conducted to synthesise existing evidence on risk factors affecting COVID-19 outcomes across Africa.Data sourcesData were systematically searched from MEDLINE, Scopus, MedRxiv and BioRxiv.Eligibility criteriaStudies for review were included if they were published in English and reported at least one risk factor and/or one health outcome. We included all relevant literature published up until 11 August 2020.Data extraction and synthesisWe performed a systematic narrative synthesis to describe the available studies for each outcome. Data were extracted using a standardised Joanna Briggs Institute data extraction form.ResultsFifteen articles met the inclusion criteria of which four were exclusively on Africa and the remaining 11 papers had a global focus with some data from Africa. Higher rates of infection in Africa are associated with high population density, urbanisation, transport connectivity, high volume of tourism and international trade, and high level of economic and political openness. Limited or poor access to healthcare are also associated with higher COVID-19 infection rates. Older people and individuals with chronic conditions such as HIV, tuberculosis and anaemia experience severe forms COVID-19 leading to hospitalisation and death. Similarly, high burden of chronic obstructive pulmonary disease, high prevalence of tobacco consumption and low levels of expenditure on health and low levels of global health security score contribute to COVID-19 related deaths.ConclusionsDemographic, institutional, ecological, health system and politico-economic factors influenced the spectrum of COVID-19 infection, severity and death. We recommend multidisciplinary and integrated approaches to mitigate the identified factors and strengthen effective prevention strategies.

The study assessed the concentration of natural radionuclides in soil samples from the Bambasi district in Ethiopia’s Benishangul Gumuz region using a gamma‐ray spectrometer equipped with a high‐purity germanium (HPGe) detector. The measured activity concentrations of 238 U, 232 Th, and 40 K in soil samples varied from 46.2 ± 2.25 to 88.49 ± 5.73 Bq/kg, 73.4 ± 4.12 to 119.65 ± 8.45 Bq/kg, and 176.78 ± 8.63 to 396.71 ± 25.39 Bq/kg, respectively. The average concentration of 238 U and 232 Th exceeded the recommended worldwide population weighted average values of 32.0 and 45.0 Bq/kg, respectively, while the average concentration of 40 K was below the recommended value of 420.0 Bq/kg. The mean absorbed dose rate was calculated to be 91.6 ± 5.1 nGy/h, which is above the recommended safe value of 59 nGy/h. The average annual effective dose equivalents for indoor and outdoor exposure were determined to be 2.65 ± 0.14 mSv/y and 0.66 ± 0.1 mSv/y, respectively. The calculated mean values of the internal hazard index, external hazard index, and gamma index across all soil samples were 0.72 ± 0.05, 0.55 ± 0.02, and 0.72 ± 0.02, respectively, all below the recommended safe threshold of one. These findings suggest that the activity concentrations observed in the soil samples exceed safe levels, indicating the necessity for further investigation into radioactivity levels and epidemiological studies regarding potential hazards from high background radiation.