Leaf pigments and wax as traits of heat tolerance in field pea

Non-Peer Reviewe

Transboundary water governance institutional architecture: reflections from Ethiopia and Sudan

Transboundary water resource governance is premised on equitable water and water-related benefit sharing. Using the case of the Blue Nile (Ethiopia and Sudan), we explore the conceptual issues that need consideration in the crafting of cross-border cooperation within the water sector. First, drawing on global experiences with transboundary water management, we evaluate how upstream and downstream concerns are addressed by transboundary water management institutions. Second, we explore the kinds of institutional design and the issues which need to be considered to result in ‘win-win’ scenarios for both upstream and downstream users, as well as the mechanisms of benefit sharing negotiated amongst different stakeholders. Third, we examine ways of addressing equity and livelihoods in transboundary institutional arrangements. Finally, we attempt to assess how transboundary institutions can address broader historical, political and economic issues and their implications for sustainable transboundary water governance. This paper raises key issues that need to be addressed in establishing transboundary governance institutions.Length: pp.246-253Water governanceInstitutionsInternational watersInternational cooperationRiver basin management

Integrated water resources management as a new approach to water security

Access to safe water is a worldwide problem facing three quarters of a billion people every day. The problem of access to water is not primarily due to an overall scarcity of water, but rather the unequal geographical and seasonal distribution of the water resources. The key issue at stake here is, how to make water available. The new approach presented by international institutions for improving water access is Integrated Water Resource Management. This chapter questions this new approach and highlights the depoliticizing implications

Water Balance Model: Implications for Groundwater Recharge Estimation in Data Scarce Arid Catchment, Northern Ethiopia

The paper presents results related to water balance model of the Gumselassa catchment (28.1 km2), Tigray, Northern Ethiopia. The catchment includes a small dam called Gumselassa dam having an effective watershed area of 22.14 km2 with reservoir capacity of 1.92 x 106 m3 and command area of about 1sq. km. The hydrology of the area was characterized on the basis of land use, soil, slope and climatic parameters. Different methods were employed in this study: rainfall coefficient method was used to determine monthly distribution of rainfall; Penman method to calculate evaporation from the reservoir; Thornthwaite method and Thornthwaite water balance model to determine potential and actual evapotranspiration; runoff coefficient method to estimate runoff; and, the water balance model was used to quantify the recharge. The catchment is characterized by one rainy season (three months) and two dry seasons (nine months) during the year. The mean annual rainfall of the catchment is 485.89 mm. The total annual water loss by evaporation from the reservoir is 1263.27 mm. The mean annual actual evapotranspiration of the effective watershed area one and two is 318.57 mm and 310.27 mm, respectively. The mean annual actual evapotranspiration of the water contributing area 1 and 2 to the command area is 337.06 mm and 355.29 mm, respectively. The mean annual actual evapotranspiration of the command area is 319.3 mm. The mean annual runoff generated from the effective watershed area one and two is 1.167 and 0.44 million cubic meters, respectively. The mean annual runoff generated from the water contributing area 1 and 2 to the command area is 0.048 and 0.349 million cubic meters, respectively. The mean annual runoff generated from the command area is 0.0875 million cubic meters. The total amount of water which is actually available to recharge the groundwater within the catchment is 4.065 million cubic meters, and any application of water for irrigation from the reservoir should take into account this readily available water

Seroprevalence of SARS-CoV-2 antibody among individuals aged above 15 years and residing in congregate settings in Dire Dawa city administration, Ethiopia

Background Determining the extent of seropositivity of SARS-CoV-2 antibody has the potential to guide prevention and control efforts. We aimed to determine the seroprevalence of SARS-CoV-2 antibody among individuals aged above15 years and residing in the congregate settings of Dire Dawa city administration, Ethiopia. Method We analyzed COVID-19 seroprevalence data on 684 individuals from a community based cross-sectional survey conducted among individuals aged above 15 years and residing in congregate settings in Dire Dawa from June 15 to July 30, 2020. Data were collected using interview and blood sample collection. Participants were asked about demographic characteristics, COVID-19 symptoms, and their practice of preventive measures. Seroprevalence was determined using SARS-CoV-2 IgG test. Bivariate and multivariate multilevel mixed effects logistic regression model was fitted and statistical significance was set at p value < 0.05. Result The estimated SARS-CoV-2 seroprevalence was 3.2% (95 % CI 2.0–4.8) in the study region with no differences by age and sex but considerable differences were observed by self-reported practice of COVID-19 preventive measures. The cluster effect is not significant (P = 0.396) which has suggested no evidence of heterogeneity in SARS-CoV-2 seroprevalence among the clusters. The odds of SARS-CoV-2 antibody seroprevalence were higher for individuals who were employed and work by moving from home to work area (AOR; 9.73 95% CI 2.51, 37.68), reported of not wearing facemasks when leaving home (AOR; 6.4 95% CI 2.30, 17.66) and did not practice physical distancing measures (AOR; 10 95% CI 3.01, 33.20) compared to their counterparts, respectively. Our estimated seroprevalence of SARS-CoV-2 among participants who reported not to have practiced social distancing measures was 12.8 (95% CI, 7.0, 19) and 1.5 (95% CI, 0.5, 2.5) among those who reported of practicing them. More than 80% of study participants reported of implementing infection prevention measures (face masks and physical distancing recommendations). Conclusion The detected SARS-CoV-2 seroprevalence among the study participants was low at the time of the survey indicating higher proportion of population yet to be infected. COVID-19 preventive measures were associated with reduced seroprevalence and should be promoted to avoid transmission to the uninfected majority

Dendritic Cells Activate and Mature after Infection with Mycobacterium tuberculosis

<p>Abstract</p> <p>Background</p> <p>Dendritic cells (DCs) can take up an array of different antigens, including microorganisms which they can process and present more effectively than any other antigen presenting cell. However, whether the interaction between the human DC and <it>Mycobacterium tuberculosis </it>represents a defense mechanism by the invaded host, or helping the invader to evade the defense mechanism of the host is still not clearly understood.</p> <p>Findings</p> <p>To analyze the interactions between <it>M. tuberculosis </it>and immune cells, human peripheral blood monocyte-derived immature DCs were infected with <it>M. tuberculosis </it>H37Rv wild type strain and flow cytometry was used to analyse cell surface expression markers. The ability of the <it>M. tuberculosis </it>infected DC to induce T cell proliferation using 5 and 6-carboxyfluorescein diacetate succinimidyl ester (CFSE) dilution technique was also investigated. DCs were found to internalize the mycobacteria and show dose dependent infection and necrosis with different multiplicity of infection. Flow cytometry analysis of cell surface expression markers CD40, CD54, CD80, CD83, CD86 and HLA DR in infected DC revealed significant (p < 0.05) up regulation following infection with <it>M. tuberculosis </it>in comparison to immature DC with no stimulation. Lipopolysaccharide (LPS) from <it>Salmonella abortus equi</it>, a known DC maturation agent, was used as a positive control and showed a comparable up regulation of cell surface markers as observed with <it>M. tuberculosis </it>infected DC. It was revealed that the <it>M. tuberculosis </it>infected DC induced T cell proliferation.</p> <p>Conclusion</p> <p>These data clearly demonstrate that <it>M. tuberculosis </it>induces activation and maturation of human monocyte-derived immature DC as well as induces T cell proliferation <it>in vitro</it>.</p

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

Bacterial cellulose-lactoferrin as an antimicrobial edible packaging

Bacterial cellulose (BC) films from two distinct sources (obtained by static culture with Gluconacetobacter xylinus ATCC 53582 (BC1) and from a commercial source (BC2)) were modified by bovine lactoferrin (bLF) adsorption. The functionalized films (BC+bLF) were assessed as edible antimicrobial packaging, for use in direct contact with highly perishable foods, specifically fresh sausage as a model of meat products. BC+bLF films and sausage casings were characterized regarding their water vapour permeability (WVP), mechanical properties, and bactericidal efficiency against two food pathogens, Escherichia coli and Staphylococcus aureus. Considering their edibility, an in vitro gastrointestinal tract model was used to study the changes occurring in the BC films during passage through the gastrointestinal tract. Moreover, the cytotoxicity of the BC films against 3T3 mouse embryo fibroblasts was evaluated. BC1 and BC2 showed equivalent density, WVP and maximum tensile strength. The percentage of bactericidal efficiency of BC1 and BC2 with adsorbed bLF (BC1+bLF and BC2+bLF, respectively) in the standalone films and in inoculated fresh sausages, was similar against E. coli (mean reduction 69 % in the films per se versus 94 % in the sausages) and S. aureus (mean reduction 97 % in the films per se versus 36 % in the case sausages). Moreover, the BC1+bLF and BC2+bLF films significantly hindered the specific growth rate of both bacteria. Finally, no relevant cytotoxicity against 3T3 fibroblasts was found for the films before and after the simulated digestion. BC films with adsorbed bLF may constitute an approach in the development of bio-based edible antimicrobial packaging systems.The authors would like to acknowledge Portuguese Foundation for Science and Technology (Fundação para a Ciência e Tecnologia) for the research grants: Jorge Padrão SFRH/BD/64901/2009, Sara Gonçalves SFRH/BD/63578/2009, João Pedro Silva SFRH/BPD/ 64958/2009, Ana Cristina Pinheiro SFRH/BPD/101181/2014. V. Sencadas thanks support from the COST Action MP1206: “Electrospun nano-fibres for bio inspired composite materials and innovative industrial applications” and MP1301: “New Generation Biomimetic and Customized Implants for Bone Engineering”. The authors would also like to thank the co-funded by the Programa Operacional Regional do Norte (ON.2 e O Novo Norte), QREN, FEDER Projects “BioHealth e Biotechnology and Bioengineering approaches to improve health quality”, Ref. NORTE-07-0124- FEDER-000027; “BioInd e Biotechnology and Bioengineering for improved Industrial and Agro-Food processes”, REF. NORTE-07- 0124-FEDER-000028; Strategic Project PEST-C/FIS/UI607/2014; Matepro eOptimizing Materials and Processes”, ref. NORTE-07- 0124-FEDER-000037; Strategic Project PEst-OE/EQB/LA0023/2013 and project ref. RECI/BBB-EBI/0179/2012 (project number FCOMP- 01-0124-FEDER-027462). Finally, the authors thank the Fundação para a Ciência e Tecnologia for the strategic funding from the UID/ BIO/04469/2013 unit

Chlamydia trachomatis Co-opts GBF1 and CERT to Acquire Host Sphingomyelin for Distinct Roles during Intracellular Development

The obligate intracellular pathogen Chlamydia trachomatis replicates within a membrane-bound inclusion that acquires host sphingomyelin (SM), a process that is essential for replication as well as inclusion biogenesis. Previous studies demonstrate that SM is acquired by a Brefeldin A (BFA)-sensitive vesicular trafficking pathway, although paradoxically, this pathway is dispensable for bacterial replication. This finding suggests that other lipid transport mechanisms are involved in the acquisition of host SM. In this work, we interrogated the role of specific components of BFA-sensitive and BFA-insensitive lipid trafficking pathways to define their contribution in SM acquisition during infection. We found that C. trachomatis hijacks components of both vesicular and non-vesicular lipid trafficking pathways for SM acquisition but that the SM obtained from these separate pathways is being utilized by the pathogen in different ways. We show that C. trachomatis selectively co-opts only one of the three known BFA targets, GBF1, a regulator of Arf1-dependent vesicular trafficking within the early secretory pathway for vesicle-mediated SM acquisition. The Arf1/GBF1-dependent pathway of SM acquisition is essential for inclusion membrane growth and stability but is not required for bacterial replication. In contrast, we show that C. trachomatis co-opts CERT, a lipid transfer protein that is a key component in non-vesicular ER to trans-Golgi trafficking of ceramide (the precursor for SM), for C. trachomatis replication. We demonstrate that C. trachomatis recruits CERT, its ER binding partner, VAP-A, and SM synthases, SMS1 and SMS2, to the inclusion and propose that these proteins establish an on-site SM biosynthetic factory at or near the inclusion. We hypothesize that SM acquired by CERT-dependent transport of ceramide and subsequent conversion to SM is necessary for C. trachomatis replication whereas SM acquired by the GBF1-dependent pathway is essential for inclusion growth and stability. Our results reveal a novel mechanism by which an intracellular pathogen redirects SM biosynthesis to its replicative niche

Sphingomyelin Synthases Regulate Protein Trafficking and Secretion

Sphingomyelin synthases (SMS1 and 2) represent a class of enzymes that transfer a phosphocholine moiety from phosphatidylcholine onto ceramide thus producing sphingomyelin and diacylglycerol (DAG). SMS1 localizes at the Golgi while SMS2 localizes both at the Golgi and the plasma membrane. Previous studies from our laboratory showed that modulation of SMS1 and, to a lesser extent, of SMS2 affected the formation of DAG at the Golgi apparatus. As a consequence, down-regulation of SMS1 and SMS2 reduced the localization of the DAG-binding protein, protein kinase D (PKD), to the Golgi. Since PKD recruitment to the Golgi has been implicated in cellular secretion through the trans golgi network (TGN), the effect of down-regulation of SMSs on TGN-to-plasma membrane trafficking was studied. Down regulation of either SMS1 or SMS2 significantly retarded trafficking of the reporter protein vesicular stomatitis virus G protein tagged with GFP (VSVG-GFP) from the TGN to the cell surface. Inhibition of SMSs also induced tubular protrusions from the trans Golgi network reminiscent of inhibited TGN membrane fission. Since a recent study demonstrated the requirement of PKD activity for insulin secretion in beta cells, we tested the function of SMS in this model. Inhibition of SMS significantly reduced insulin secretion in rat INS-1 cells. Taken together these results provide the first direct evidence that both enzymes (SMS1 and 2) are capable of regulating TGN-mediated protein trafficking and secretion, functions that are compatible with PKD being a down-stream target for SMSs in the Golgi