The frankincense tree of Ethiopia : ecology, productivity and population dynamics

Keywords: Boswellian papyrifera, Frankincense tree, matrix model, population dynamics, population bottleneck, tapping. Combretum – Terminalia woodlands and Acacia – Commiphora woodlands are the two dominant vegetation types that cover large parts of the dry land areas in Ethiopia. Several of their tree and shrub species yield economically valuable products such as gum Arabic, frankincense and myrrh. Boswellia papyrifera provides the widely traded frankincense that accounts for >80% of the export revenues that the country is earning from gum and resin resources. Unfortunately, the Ethiopian dry woodlands and the B. papyrifera populations are disappearing rapidly due to the combined effects of over-harvesting gums and resins, overgrazing by livestock, recurrent fires, and excessive wood harvesting. The current lack of small saplings in the remaining populations of Boswellia suggests that the populations may not be sustained for the future. The main objectives of this thesis were to determine diversity and production patterns in B. papyrifera dominated dry woodlands, to show the regeneration status in various B. papyrifera populations, and to evaluate the effects of environment, frankincense harvesting, and grazing on the population dynamics of B. papyrifera. The main research questions were: (1) how do environmental conditions affect the tree/shrub species richness and production of Ethiopian dry woodlands? (2) what factors determine the frankincense production by B. papyrifera trees? (3) how do the vital rates and population dynamics of B. papyrifera vary across habitats that differ in soil conditions and biotic factors? (4) What are the major bottlenecks in the life cycle of the trees that hinder the sustainability of the remaining populations? To address these questions, tree populations were studied in the highlands of Abergelle and the lowlands of Metema. Metema also has a longer wet season length, higher annual rainfall and better soil fertility status than Abergelle. In total 36 and 22 tree and shrub species representing 20 and 9 families were recorded in Metema and Abergelle woodlands, respectively. The most dominant plant families were Burseraceae, Fabaceae, Combretaceae and Anacardiaceae. The vegetation at both sites was dominated by B. papyrifera. The two sites differed in species richness, diversity and production. Metema, the site with the longer wet season, had a higher species richness, diversity and production than Abergelle. The productivity of woodlands also increased with a higher clay content and greater soil depth. Populations structures indeed lacked the saplings, except for one very isolated population on a steep mountain slope. The studied frankincense trees produced 41 to 840 gram of frankincense during a year with seven collection rounds, and 185 to 1826 gram of frankincense during a year with 14 collection rounds. The variation in frankincense production was large across individuals. Frankincense production increased with tree size, tapping intensity, and tapping frequency. The increase in production, however, levelled-off beyond a stem diameter of 20 cm, a tapping intensity of 9 spots, and a tapping intensity of 10 rounds. Growth rate, survival rate and fruiting probability varied across populations, but were not related to soil conditions or biotic factors. The growth rates of the 12 Metema populations varied between 0.86 to 0.98, suggesting that they were all decreasing. Matrix model analyses indicated that the mortality of adult trees was the major bottleneck for sustainable population growth, and that the lack of sapling recruitment was a second major bottleneck. These bottlenecks appear both in tapped and non-tapped stands. Remarkably, tapped stand showed higher growth rates than nontapped stands, probably because productive stands were selected for harvesting resin. All results suggest that the remaining populations of B. papyrifera will disappear in the near future if the current situation continues. Frankincense production is expected to halve in 15- 20 years. Unexpectedly, tapping had no negative effect on vital rates, nor on population growth rates indicating that other factors are responsible for the decline of the populations. Adult mortality by insect infestation and windfall, and the negative impact of grazing and fire on the establishment of saplings need extra attention. Management should be directed towards releasing two major population bottlenecks (improve sapling regeneration, reduce adult mortability) to maintain the Boswellia populations and frankincense production in the future. </p

On the novel chemical switching reforming (csr) reactor for hydrogen production with integrated co2 capture

Membrane reactors has recently emerged as one of the most promising technologies for pure hydrogen production as these reactors integrate the catalytic reactions, mostly reforming and water-gas shift reactions for hydrogen generation, and separation through membranes in a single unit. This combination of process units brings a high degree of process intensification with additional benefits in terms of increased process efficiencies. Recently, a novel MA-fluidized bed reactor concept has been proposed for pure hydrogen production with integrated CO2 capture from steam methane reforming. The so-called Chemical Switching Reforming reactor utilizes an oxygen carrier which acts as catalyst and heat carrier to the endothermic reforming reaction and is periodically exposed to fuel/steam and air streams; when air is fed to the reactor, the oxygen carrier is heated by the exothermic solids oxidation reaction, this heat is then utilized in the fuel stage where endothermic reduction and catalytic reactions regenerate the oxygen carrier and produce syngas. A hydrogen perm-selective membrane (¨thin-Pd-membrane) is used to directly recover pure hydrogen produced during steam-methane reforming while simultaneously shifting steam reforming and water-gas shift reactions equilibria towards complete conversion at lower temperatures. The CSR concept brings large benefits in design simplification, scale up and ease of operation at elevated pressure. This paper presents preliminary experimental tests on a lab scale CSR reactor ( Fig. 3) without membrane operated under auto-thermal reforming (ATR) conditions. Experimental tests investigating the influence of reactor temperature, steam to carbon ratio and feed flowrate on the reactor performance will be presented. Please click Additional Files below to see the full abstract

The effect of gas extraction through vertical membranes on the bubble hydrodynamics in a fluidized bed reactor

Recently membrane-assisted fluidized bed reactors (MAFBRs) have emerged as a cutting-edge technology for intensification of a number of industrially important chemical processes. Such reactors combine the benefits of excellent separation properties of membranes and the excellent heat and mass transport characteristics of fluidized beds. Hydrogen production from methane reforming is one of the main applications of MAFBRs where H2 perm-selective membranes are employed to extract ultra-pure hydrogen and increase product yield. Understanding the effect of inserted membranes on the hydrodynamic behaviour of the fluidized bed reactor is of high importance for the design and optimization of MAFBRs. In particular, bubble properties (size, number and velocity) strongly influence the performance of fluidized bed reactors as they play a major role in heat and mass transfer phenomena. This work presents the experimental results of the effect of gas extraction via vertical membranes on the bubble properties using a Digital Image Analysis (DIA) technique. A pseudo 2D experimental setup ( Fig. 1) with a multi-chamber porous plate mounted at the bottom of the back plate is used to simulate vertical membranes. This setup allows for gas extraction in specific locations from the back of the column. Thus the effects of vertical membranes (gas extraction rates and locations) on the bubble properties for different particle sizes and fluidization velocities are studied in great detail. Results showed that variation of gas extraction rates ( Fig. 2a) and locations ( Fig. 2b) significantly influences bubble properties. Please click Additional Files below to see the full abstract

Livestock Greenhouse Gas Emissions in Ethiopia by region: a graphic summary

This report is based on the Inventory of GHG emissions from cattle, sheep, and goats in Ethiopia (1994-2018) calculated using the IPCC Tier 2 approach approved by the Ministry of Agriculture (Wilkes et al., 2020). That national inventory report presented in detail the data sources, methods and results for GHG emissions from cattle, sheep and goats at the national level. This report summarizes the main results for each region in Ethiopia

Evaluation of the diagnostic performance of PanbioTM Abbott SARS-CoV-2 rapid antigen test for the detection of COVID-19 from suspects attending ALERT center

BACKGROUND: The emergence and rapid spread of coronavirus disease 2019 (COVID-19), a potentially lethal disease caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), is causing public health issues around the world. In resource-constrained nations, rapid Abbott SARS-CoV-2 antigen test kits are critical for addressing diagnostic gaps in health institutions and community screening. However, there is no evidence or proof of diagnostic performance in Ethiopia. The aim of this study was to compare the performance of PanbioTM Abbott SARS-CoV-2antigen rapid test kit to the gold standard, RT-PCR, in COVID-19 patients with clinical symptoms suggestive of COVID-19. METHOD: A prospective, cross-sectional study was conducted between November 2021 and April 2022, on 120 suspected patients recruited from outpatient, emergency, and intensive care units in one of the tertiary hospitals in Ethiopia. Nasopharyngeal swabs were collected from suspected cases and were tested using the Abbott SARS-CoV-2 kit, a rapid diagnostic test (RDT) and compared to the reference standard RT-PCR. RESULT: The sensitivity and specificity of the RDT were 74.2% and 100%, respectively. A total of 62 samples (51.6%) were RT-PCR positive. Of these, 46 were Ag-RDT positive. Sensitivity among symptomatic patients was 79.4% (95% CI 68.3-90). The Abbot RDT and RT-PCR had a Kappa value of agreement of 0.735 (p < 0.001). These values were acceptable when compared to the WHO's suggested thresholds. CONCLUSION: The finding from this study support the use of the Abbot RDT as a diagnostic tool in COVID-19 suspects, mainly in those with higher viral loads

High seroprevalence of anti-SARS-CoV-2 antibodies among Ethiopian healthcare workers

BACKGROUND: COVID-19 pandemic has a devastating impact on the economies and health care system of sub-Saharan Africa. Healthcare workers (HWs), the main actors of the health system, are at higher risk because of their occupation. Serology-based estimates of SARS-CoV-2 infection among HWs represent a measure of HWs' exposure to the virus and could be used as a guide to the prevalence of SARS-CoV-2 in the community and valuable in combating COVID-19. This information is currently lacking in Ethiopia and other African countries. This study aimed to develop an in-house antibody testing assay, assess the prevalence of SARS-CoV-2 antibodies among Ethiopian high-risk frontline HWs. METHODS: We developed and validated an in-house Enzyme-Linked Immunosorbent Assay (ELISA) for specific detection of anti-SARS-CoV-2 receptor binding domain immunoglobin G (IgG) antibodies. We then used this assay to assess the seroprevalence among HWs in five public hospitals located in different geographic regions of Ethiopia. From consenting HWs, blood samples were collected between December 2020 and February 2021, the period between the two peaks of COVID-19 in Ethiopia. Socio-demographic and clinical data were collected using questionnaire-based interviews. Descriptive statistics and bivariate and multivariate logistic regression were used to determine the overall and post-stratified seroprevalence and the association between seropositivity and potential risk factors. RESULTS: Our successfully developed in-house assay sensitivity was 100% in serum samples collected 2- weeks after the first onset of symptoms whereas its specificity in pre-COVID-19 pandemic sera was 97.7%. Using this assay, we analyzed a total of 1997 sera collected from HWs. Of 1997 HWs who provided a blood sample, and demographic and clinical data, 51.7% were females, 74.0% had no symptoms compatible with COVID-19, and 29.0% had a history of contact with suspected or confirmed patients with SARS-CoV-2 infection. The overall seroprevalence was 39.6%. The lowest (24.5%) and the highest (48.0%) seroprevalence rates were found in Hiwot Fana Specialized Hospital in Harar and ALERT Hospital in Addis Ababa, respectively. Of the 821 seropositive HWs, 224(27.3%) of them had a history of symptoms consistent with COVID-19 while 436 (> 53%) of them had no contact with COVID-19 cases as well as no history of COVID-19 like symptoms. A history of close contact with suspected/confirmed COVID-19 cases is associated with seropositivity (Adjusted Odds Ratio (AOR) = 1.4, 95% CI 1.1-1.8; p = 0.015). CONCLUSION: High SARS-CoV-2 seroprevalence levels were observed in the five Ethiopian hospitals. These findings highlight the significant burden of asymptomatic infection in Ethiopia and may reflect the scale of transmission in the general population

Maternal metabolic factors and the association with gestational diabetes: a systematic review and meta-analysis

First published: 14 April 2022Gestational diabetes (GDM) is associated with several adverse outcomes for the mother and child. Higher levels of individual lipids associate with risk of GDM, and metabolic syndrome, a clustering of risk factors also increases risk for GDM. Metabolic factors can be modified by diet and lifestyle. This review comprehensively evaluates the association between metabolic syndrome and its components, measured in early pregnancy, and risk for GDM. Databases (CINAHL, PubMed, Embase, and Cochrane Library) were searched from inception to 5 May 2021. Eligible studies included ≥1 metabolic factor (waist circumference, blood pressure, fasting plasma glucose, triglycerides, and high-density lipoprotein cholesterol, measured at 2 . Data were pooled by random-effects models and expressed as odds ratio and 95% confidence intervals. Of 7213 articles identified, 40 unique articles were included in meta-analysis. In analyses adjusting for maternal age and body mass index, GDM was increased with increasing fasting plasma glucose (OR 1.92; 95% CI 1.39-2.64, k=7 studies) or having metabolic syndrome (OR 2.52; 1.65, 3.84, k=3). Women with overweight (OR 2.17; 95% CI 1.89, 2.50, k=12) or obesity (OR 4.34; 95% CI 2.79-6.74, k=9) also were at increased risk for GDM. Early pregnancy assessment of glucose or the metabolic syndrome, offers a potential opportunity to detect and treat individual risk factors as an approach toward GDM prevention; weight loss for pregnant women with overweight or obesity is not recommended. This article is protected by copyright. All rights reserved.Nahal Habibi, Aya Mousa, Chau Thien Tay, Mahnaz Bahri Khomami, Thiannon K. Patten, Prabha H. Andraweera, Molla Wassie, Jared Vandersluys, Ali Aflatounian, Tina Bianco-Miotti, Shao J. Zhou, Jessica A. Griege

Cultural drivers of reforestation in tropical forest groves of the Western Ghats of India

Sacred forest groves in the Western Ghats of India are small fragments of tropical forest that have received protection due to religious beliefs and cultural practices. These forest fragments are an example of community-based conservation and they serve as refugia for many forest-dwelling species in otherwise highly anthropogenic tropical forest-agriculture landscapes of the Indian Western Ghats. Many of these sacred forest groves are considered ancient woodlands, but there is very little information on their origins. For instance: How old are these sacred groves? Are they relics of forest that was once continuous or are they patches of regenerated vegetation? How do changes in the surrounding landscape influence the vegetation in these groves? Based on palaeoecological reconstruction in two such sacred forest groves, we determined the age of these forest fragments. Both reconstructions indicate transition from non-forest open landscape to tree-covered landscape at these sites. These finding from two sacred groves challenge the common perception that sacred forest groves are remnants of once-continuous forest; instead, some sacred groves such as those studied might be regenerated forest patches that are approximately 400 years old. This further raises a number of questions about the drivers of reforestation in these groves. What were the social and cultural circumstances which led to the recovery of forest within these patches? How did land tenure influence forest recovery? What role did religious beliefs play in forest restoration? Using Wallace’s (1956) framework of ‘cultural revitalization’ and based on historical literature and palaeoecological analysis of the two sacred groves, this paper examines the drivers of reforestation in the Western Ghats of India. It suggests various social, ecological and economic drivers of such revitalization, recognizing strong linkages between the ‘social’ and the ‘ecological’ within the social–ecological system of sacred forest groves. This example of reforestation suggests that contemporary restoration of forests needs to operate at a landscape scale and look at restoration as a social–ecological intervention in forest management

Chronic myelomonocytic leukemia in younger patients : molecular and cytogenetic predictors of survival and treatment outcome

In patients with chronic myelomonocytic leukemia (CMML), age>65 years is an adverse prognostic factor. Our objective in the current study was to examine risk factors for survival and treatment outcome in 261 'young' adults with CMML, as defined by age \u2a7d65 years. In multivariable analysis, lower HB (P=0.01), higher circulating blast % (P=0.002), ASXL1 (P=0.0007) and SRSF2 mutations (P=0.008) and Mayo-French cytogenetic stratification (P=0.04) negatively impacted survival. Similarly, leukemia-free survival was independently affected by higher circulating blast % (P<0.0001), higher bone marrow blast % (P=0.0007) and the presence of circulating immature myeloid cells (P=0.0002). Seventy-five (29%) patients received hypomethylating agents (HMA), with the median number of cycles being 5, and the median duration of therapy being 5 months. The over-all response rate was 40% for azacitidine and 30% for decitabine. Fifty-three (24%) patients underwent an allogeneic hematopoietic stem cell transplant (AHSCT), with a response rate of 56% and a non-relapse mortality of 19%. Survival in young adults with CMML, although higher than in older patients, is poor and even worse in the presence of ASXL1 and SRSF2 mutations. Treatment outcome was more impressive with AHSCT than with HMA and neither was influenced by ASXL1/SRSF2 mutations or karyotype