Preliminary Results of the Archaeological Reconnaissance carried out in Atsibi -Wemberta, Eastern Tigray, Ethiopia

Archaeological reconnaissance sponsored by the Authority for Research and Conservation of Cultural Heritage (ARCCH) was conducted under the direction of the author in February 2004 in Atsibi-Wemberta district (Wereda) in eastern Tigray Administrative Zone. The objective of the archaeological ground reconnaissance was to assess the archaeological and tourism potential of the same place and to prepare the ground for future research. The preliminary assessment survey resulted with the discoveries of several settlements, cemeteries and religious sites ascribable to the pre-Aksumite and Aksumite cultures dating to about the middle of the first millennium BC and the first seven centuries AD, respectively.Key words: cemetery, settlement, stelae, Tumulus

THE ROLE OF MEMBRANE TRANSPORTERS IN TRAUMATIC BRAIN INJURY: INTERVENTIONAL AND GENETIC INVESTIGATIONS

Traumatic brain injury (TBI) is a leading cause of death and disability in children and young adults in the US. The neurovascular unit conceptual frame work emphasizes the dynamic interplay between neurons, endothelial cells and glial cells in understanding the pathophysiology of TBI. Membrane transporters, as mediators of the movement of numerous endogenous and exogenous molecules within the neurovascular unit, are critical components of the functional neurovascular unit in TBI. The aim of this thesis is to understand the role of membrane transporters in the pathogenesis and pharmacotherapy of TBI through interventional and genetic approaches. In the first part of the thesis, we investigated the utility of inhibition of transporters with probenecid, as a therapeutic strategy to simultaneously increase the systemic and brain concentration of the anti-oxidant drug, n-acetylcysteine, and the endogenous anti-oxidant, glutathione, in TBI. This approach counters oxidative stress, a major injury mechanism in TBI. Preclinical pharmacokinetic study showed that probenecid increases plasma and brain levels of n-acetylcysteine by inhibiting OAT1 and OAT3 transporters. In rat model of pediatric TBI, n-acetylcysteine showed potential in attenuating TBI-induced learning and memory deficits. Probenecid caused transient motor function impairment. A combination of the two resulted in smaller cortical tissue volume loss. Optimization of dosage regimen for both drugs to enhance the effects of n-acetylcysteine and minimize the side effects of probenecid is warranted. Metabolomic and pathway analyses of cerebrospinal fluid of TBI patients treated with placebo or a combination of probenecid and n-acetylcysteine showed that the combination therapy enriched glutathione-mediated anti-oxidative stress pathways. In the second part of this thesis, we examined the association of genetic alterations in monocarboxylate transporters – responsible for shuttling lactate within the neurovascular unit –with clinical outcomes. In discovery and replication cohorts, patients with one or two alternate alleles at SLC16A7 rs10506399 showed favorable outcomes. The alternate allele at the SNP was associated with increased expression of SLC16A7 which suggests that increased uptake of lactate by neurons may be beneficial in TBI. Collectively, this work has provided interventional and genetic evidence that transporters are important component of the injury mechanism and attractive therapeutic targets in TBI

FOOD-FOR-WORK FOR POVERTY REDUCTION AND THE PROMOTION OF SUSTAINABLE LAND USE: CAN IT WORK?

Food-for-work (FFW) programs are commonly used both for short-term relief and long-term development purposes. In the latter capacity, they are increasingly used for natural resources management projects. Barrett, Holden and Clay (forthcoming) assess the suitability of FFW programs as insurance to cushion the poor against short-term, adverse shocks that could, in the absence of a safety net, have permanent repercussions. In this paper we explore the complementary question of FFW programs' potential to reduce poverty and promote sustainable land use in the longer run through induced changes in investment patterns. FFW programs commonly aim to produce or maintain potentially valuable public goods necessary to stimulate productivity and thus income growth. Among the most common projects are road building, reforestation, and the installation of terracing or irrigation. In the abstract, public goods such as these are unambiguously good. There is a danger, however, that such programs could discourage private soil and water conservation and crowd out private investment. How important are such effects and when are these effects small or large and when and how can they be reduced? How do market characteristics, timing and design of FFW programs affect this? When, where and how can FFW programs more efficiently reduce poverty and promote more sustainable land management? The paper aims to answer these questions. Much recent empirical research has focused on the shorter-term targeting issue of whether FFW and related workfare programs efficiently target the poor (Dev 1995, Von Braun 1995, Webb 1995, Subbarao 1997, Clay et al. 1998, Devereux 1999, Jayne et al. 1999, Ravallion 1999, Teklu and Asefa 1999, Atwood et al. 2000, Gebremedhin and Swinton 2000, Haddad and Adato 2001, Jalan and Ravallion 2001). Much less research has been focused on the longer-term effects of FFW. Yet the large share of hunger worldwide arises due to chronic deprivation and vulnerability, not short-term shocks (Speth 1993, Barrett 2002). Also most of the FFW programs in Ethiopia have long-term development goals and are formally distinguished from the disaster relief FFW programs (Aas and Mellemstrand 2002). It is therefore appropriate to evaluate these programs based on their long-term goals and not only on the basis of short-term targeting. In a case study in Tigray Aas and Mellemstrand (2002) found that the FFW recipients considered the long-term benefits of FFW as more important than the short-term benefits of food provision. FFW programs may produce valuable public goods. For example, Von Braun et al. (1999) report multiplier effects of a FFW-built road in the Ethiopian lowlands. Public provision of public goods may be socially desirable because private investment in soil and water conservation and tree planting may be well below socially optimal levels due to poverty and market imperfections (Holden, Shiferaw and Wik 1998, Holden and Shiferaw 2002, Holden and Yohannes 2002, Pender and Kerr 1998), tenure insecurity (Gebremedhin and Swinton 2000, Holden, Benin, Shiferaw and Pender 2003), lack of technical knowledge and coordination problems across farms (Hagos and Holden 2002). There is, however, also a danger that FFW programs crowd out private investments (Gebremedhin and Swinton 2000). We analyze these issues using multiple methods. First, section II introduces a simple theoretical framework for understanding the analytically ambiguous effects of FFW programs on sustainable land use patterns. We first present the basic intuition in a static framework to illustrate the selection, crowding out and targeting issues, before generalizing it to a dynamic model to illustrate the possible insurance and crowding in effects of FFW. Section III then uses an applied, dynamic bio-economic farm household model applied to a less-favoured area in Ethiopia to investigate via numerical simulation how household welfare and land use patterns vary with changes in environmental and FFW program design parameters. Section IV presents econometric evidence based on survey panel data from northern Ethiopia to assess the relationship between FFW and private investment in conservation. Section V discusses our findings and fleshes them out a bit with further empirical evidence. Section VI concludes.Food Security and Poverty, Q18, O1, Q2, I1,

Towards a results-based performance management: practices and challenges in the Ethiopian public sector

The purpose of this research is to propose a strategy of managing performance in the public sector. The primary data have been collected through questionnaires administered to managers and professionals; and interviews administered to heads of planning and ICT departments.  Secondary data were collectedthrough reviewing documents (plans, reports,proclamations and regulation). Findings of this study indicate that  performance management system is disconnected at the top that weakened accountability of managers in the public sector. Besides, agencies responsible for performance management have not developed systems to monitor and evaluate performances of public organisations and their managers. As a matter of fact, public organisations have made a lot of progress in introducing LAN, developing web pages and using the internet for information sharing. However, they have not developed  database systems and computerized MIS that are important for the management of performance. The other problem of managing  performance in the public sector is the different agencies that are directly or indirectly involved in managing the performance of a particular public organisation. These are: first, the organisation itself, which is striving to implement BSC; second, the Planning and Budgeting unit of MoFED, which has not gone beyond the traditional activities of compiling plans and performance reports of public organisations, but attempting to implement Performance Based Budgeting, and finally, the Ministry of Civil Service, which is responsible for preparing guidelines for evaluation of employee performance. To emphasise the importance of performance management in the public sector, the Ethiopian government can learn from the  experiences of some African countries, which have organised  performance management units under the offices of Prime Ministers.Keywords: Results-Based Performance Management, balanced scorecard, process control, accountability, reward systems, organizational capacity, MIS

Time-dependent patterning of the mesoderm and endoderm by Nodal signals in zebrafish

BACKGROUND: The vertebrate body plan is generated during gastrulation with the formation of the three germ layers. Members of the Nodal-related subclass of the TGF-β superfamily induce and pattern the mesoderm and endoderm in all vertebrates. In zebrafish, two nodal-related genes, called squint and cyclops, are required in a dosage-dependent manner for the formation of all derivatives of the mesoderm and endoderm. These genes are expressed dynamically during the blastula stages and may have different roles at different times. This question has been difficult to address because conditions that alter the timing of nodal-related gene expression also change Nodal levels. We utilized a pharmacological approach to conditionally inactivate the ALK 4, 5 and 7 receptors during the blastula stages without disturbing earlier signaling activity. This permitted us to directly examine when Nodal signals specify cell types independently of dosage effects. RESULTS: We show that two drugs, SB-431542 and SB-505124, completely block the response to Nodal signals when added to embryos after the mid-blastula transition. By blocking Nodal receptor activity at later stages, we demonstrate that Nodal signaling is required from the mid-to-late blastula period to specify sequentially, the somites, notochord, blood, Kupffer's vesicle, hatching gland, heart, and endoderm. Blocking Nodal signaling at late times prevents specification of cell types derived from the embryo margin, but not those from more animal regions. This suggests a linkage between cell fate and length of exposure to Nodal signals. Confirming this, cells exposed to a uniform Nodal dose adopt progressively more marginal fates with increasing lengths of exposure. Finally, cell fate specification is delayed in squint mutants and accelerated when Nodal levels are elevated. CONCLUSION: We conclude that (1) Nodal signals are most active during the mid-to-late blastula stages, when nodal-related gene expression and the movement of responding cells are at their most dynamic; (2) Nodal signals specify cell fates along the animal-vegetal axis in a time-dependent manner; (3) cells respond to the total cumulative dose of Nodal signals to which they are exposed, as a function of distance from the source and duration of exposure

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

Solid Oxide Fuel Cell design and Application of Formal Methods

The design of solid oxide fuel cells has inherent conflicts and compromises due to the mechanical and electrochemical requirements. The design objective is to reduce the fabrication cost of cell components while maintaining high efficiency and reliability. Solid oxide fuel cells have yet to go through a lot of research and development stage before they can be commercialised to replace conventional power generating devices. The cost associated with manufacturing of cells and stack has proved to be prohibitively high at this stage of the development. To overcome this, a cost effective manufacturing process and associated design was needed. Taguchi method of experimentation was employed to this end. Design Function Deployment (DFD) methodology was used to compare and develop previous conceptual designs and a new combined design is proposed. Mathematical models were developed to include, fluid flow pattern across the manifold, electrochemical reactions within the cell, and stress profile across the cell and stack. The results were used in conjunction with correlation chains to establish an optimal design. A new roof for the DFD main chart is proposed to incorporate mathematical models into the design process and arrive at a mathematically optimised solution