Sesame webworm (Antigastra catalaunalis) is the major pest, which is causing heavy losses in Humera areas, northern Ethiopia. The present study aims to determine schedule of insecticide application for control of the pest. An experiment... more
Sesame webworm (Antigastra catalaunalis) is the major pest, which is causing heavy losses in Humera areas, northern Ethiopia. The present study aims to determine schedule of insecticide application for control of the pest. An experiment with a randomized complete block design (RCBD) was conducted at Humera Agricultural Research Center to evaluate nine insecticide application schedules. Result of the experiment indicated that weekly spray (S9) resulted in lower webworm incidence (19.5%) and better grain yield (536.6 kg/ha); and highest incidence (99.27%) and lowest grain yield (154.9 kg/ha) was recorded from control. Maximum level of leaf and flower was scored on control and once sprayed plots, while the lowest was on the frequently sprayed. In conclusion, twice application of insecticide at 2 and 4 weeks after emergence was found better for controlling A. catalaunalis.
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Across the surveyed areas on average, 41.5% (range: 6.7 to 96.7%) and 12.3% (range: 0 to 90%) of the groundnut kernels were found to be infected by A. flavus and A. niger, respectively. Despite variations in contamination level among... more
Across the surveyed areas on average, 41.5% (range: 6.7 to 96.7%) and 12.3% (range: 0 to 90%) of the groundnut kernels were found to be infected by A. flavus and A. niger, respectively. Despite variations in contamination level among location, Aflatoxin B1 type was detected in all the samples. The detected aflatoxin concentrations were ranging from 0.1 to 397.8 ppb (mean: 28.7 and median 5.2 ppb). The highest level of Aflatoxin was detected in groundnut samples from T. abergele area (55.3 ppb). By All standards, according to the EU and FAO food safety guidelines for direct human consumption, before processing and EU import limits, the qualities of the analyzed groundnut samples were very low, and significant amount of the samples were unsafe for human consumption as well as unfit for international market. The prevalence of the toxigenic fungi and associated extent of groundnut contamination in the region calls for urgent interventions of management practices to reduce the impact and awareness creation in the public.
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Sesame (Sesamum indicum L.) is one of the important oil seed crops in Ethiopia. It is famous for international market and its production is challenged by inappropriate agronomic practices, insect pest infestation and weather... more
Sesame (Sesamum indicum L.) is one of the important oil seed crops in Ethiopia. It is famous for international market and its production is challenged by inappropriate agronomic practices, insect pest infestation and weather uncertainties. Sesame webworm, Antigastra catalaunalis is a major pest in western Tigray. To assess the incidence and severity of A. catalaunalis, a survey was conducted in western zone of Tigray (Kafta Humera, Tsegede and Welkait) in 2015 cropping season starting from seedling up to capsule development stages. A total of 48 farm plots was assessed for prevalence, incidence and severity. All surveyed farm plots were infested at all stages of the crop. In the study area incidence of the pest was 66% and 15% capsule damage/severity. Capsule developmental stage of the crop was the most infested crop growth stage in the surveyed Original Research Article
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Opals are widespread within Miocene volcanic sequences in the North Shoa province of Central Ethiopia. The opal occurs as cavity fillings in a 5 m thick seam of glassy rhyolitic ignimbrite that is sandwiched between basaltic lava flows.... more
Opals are widespread within Miocene volcanic sequences in the North Shoa province of Central Ethiopia. The opal occurs as cavity fillings in a 5 m thick seam of glassy rhyolitic ignimbrite that is sandwiched between basaltic lava flows. The opals occur over a large area (>25 km2). X-ray diffraction analyses show that they are CT-type. The opals contain lower concentrations of trace elements (up to 100 times) than the host rhyolite. Ratios of most trace elements are, however, similar in both the opals and rhyolites. The opals have high δ18O values (28.4–33.8‰) that imply a low temperature of formation, between 20.55 and 25.74 °C. We therefore propose that the opals precipitated from meteoric waters that had percolated through and interacted with the host rhyolite. Field evidence indicates that this weathering and alteration occurred immediately after emplacement of the rhyolites, but prior to the extrusion of the overlying basalt flows.
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Across the surveyed areas on average, 41.5% (range: 6.7 to 96.7%) and 12.3% (range: 0 to 90%) of the groundnut kernels were found to be infected by A. flavus and A. niger, respectively. Despite variations in contamination level among... more
Across the surveyed areas on average, 41.5% (range: 6.7 to 96.7%) and 12.3% (range: 0 to 90%) of the groundnut kernels were found to be infected by A. flavus and A. niger, respectively. Despite variations in contamination level among location, Aflatoxin B1 type was detected in all the samples. The detected aflatoxin concentrations were ranging from 0.1 to 397.8 ppb (mean: 28.7 and median 5.2 ppb). The highest level of Aflatoxin was detected in groundnut samples from T. abergele area (55.3 ppb). By All standards, according to the EU and FAO food safety guidelines for direct human consumption, before processing and EU import limits, the qualities of the analyzed groundnut samples were very low, and significant amount of the samples were unsafe for human consumption as well as unfit for international market. The prevalence of the toxigenic fungi and associated extent of groundnut contamination in the region calls for urgent interventions of management practices to reduce the impact and...
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Upcoming applications, such as autonomous vehicles, will pose strict requirements on the vehicular networks. In order to provide these new services reliably, an accurate understanding of propagation in the vehicular scenarios is needed.... more
Upcoming applications, such as autonomous vehicles, will pose strict requirements on the vehicular networks. In order to provide these new services reliably, an accurate understanding of propagation in the vehicular scenarios is needed. In this context, this paper presents a measurementbased evaluation of large vehicle shadowing at 5.8 GHz in V2X scenarios. The receiver antenna height is fixed to average vehicular height (1.5 m), while the transmitter antennas are located at different heights (1.5, 5, and 7 m) in order to investigate both V2V and V2I scenarios. A truck was used to obstruct the LOS between transmitter and receiver, and a large number of geometrical combinations of the scenario were explored. The statistical analysis of the measurement shows how in the V2V case, the experienced shadow levels are approximately 5 dB higher than in the V2I scenarios, where the shadow levels depend on the transmitter antenna height, reaching maximum values of 21-23 dB. The statistical ana...
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The objective of this study was to find sources of resistance to Fusarium ear rot and fumonisin accumulation in maize germplasm. Totally 15 maize cultivars were evaluated by means of silk channel inoculation using a fumonisin producing F.... more
The objective of this study was to find sources of resistance to Fusarium ear rot and fumonisin accumulation in maize germplasm. Totally 15 maize cultivars were evaluated by means of silk channel inoculation using a fumonisin producing F. verticillioides isolate in field trials during 2013 and 2014 cropping seasons. Fusarium ear rot severity was determined at harvest, and fumonisin content was quantified using competitive Enzyme Linked Immunosorbent Assay (ELISA). The percentage of infected kernels per maize ear after inoculation, ranged from 5% to 60% in 2013 and from 3% to 40% in 2014. Fumonisin accumulation in maize cultivars ranged from 2700 to 76300 µg/kg in 2013 and from 1800 to 52700 µg/kg in 2014. Maize cultivars Berihu, Melkassa-2, Melkassa-7, Melkassa-4, BHQP542 and MHQ-138 showed low level of ear rot (3.9% to 22.9%) and total fumonisins (2300 to 17300 µg/kg) across the two years experiment. Cultivars that had low disease severity are useful in breeding programs aiming at ...
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Background: Adequate phosphorus (P) and foliar zinc (Zn) in groundnut required for obtaining Zn-enriched grain and optimum yield. However, it was very low in the area. Due to that, the study investigated the response of groundnut... more
Background: Adequate phosphorus (P) and foliar zinc (Zn) in groundnut required for obtaining Zn-enriched grain and optimum yield. However, it was very low in the area. Due to that, the study investigated the response of groundnut genotypes to combined application of phosphorus and zinc on yield and nutritional content. Methods: A field experiment was conducted at Sheka-Tekli in 2017/18 cropping season. The treatments were consisted of three groundnut genotypes (ICGV00308, ICGV91114 and Sedi) as main plot and four combined (P with Zn) fertilizer levels (00(F 0 ), 10 kg P/ha +0.50 g Zn/L(F 1 ), 20 kg P/ha +1 g Zn/L(F 2 ) and 30 kg P/ha+1.5 g Zn/L(F 3 ) as sub plot was assigned in split plot design. Result: The genotype and combined fertilizer main effect had significance effect on days to 50% flowering and days to 50% maturity. They had also a significant effect on hundred seed weight and leaf length, respectively. Number of pods/plant, pod yield/ha, number of seeds/pod, seed yield kg...
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5G is targeting a peak data rate in the order of 10 Gb/s and at least 100 Mb/s data rate is generally expected to be available everywhere. For fulfilling such 5G broadband targets, massive deployment of small cells is considered as one of... more
5G is targeting a peak data rate in the order of 10 Gb/s and at least 100 Mb/s data rate is generally expected to be available everywhere. For fulfilling such 5G broadband targets, massive deployment of small cells is considered as one of the promising solutions. However, inter-cell interference leads to significant limitations on the network throughput in such deployments. In addition, network densification introduces difficulty in network deployment. This paper presents a study on the benefits of advanced receiver in a practical uncoordinated dense small cells deployment. Our aim is to show that advanced receivers can alleviate the need for detailed cell planning. To this end we adopt a hybrid simulation evaluation approach where propagation data are obtained from experimental analysis, and by which we analyse how MIMO constellation and network size impacts to the aim. The experimental data have been obtained using a software defined radio (SDR) testbed network with 12 testbed nodes, configured as either access point or user equipment. Each node features a \(4 \times 4\) or a \(2 \times 2\) MIMO configuration. The results demonstrate that advanced receivers with a larger MIMO antenna configuration significantly improves the throughput performance in a practical dense small cells network due to the interference suppression capability. In addition, the results prove that the operators can rely on uncoordinated deployment of small cells, since the resulting interference can be suppressed by the advanced receiver processing with sufficiently capable MIMO antenna configuration.
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Sesame (Sesamum indicum L.) is one of the important oil seed crops in Ethiopia. It is famous for international market and its production is challenged by inappropriate agronomic practices, insect pest infestation and weather... more
Sesame (Sesamum indicum L.) is one of the important oil seed crops in Ethiopia. It is famous for international market and its production is challenged by inappropriate agronomic practices, insect pest infestation and weather uncertainties. Sesame webworm, Antigastra catalaunalis is a major pest in western Tigray. To assess the incidence and severity of A. catalaunalis, a survey was conducted in western zone of Tigray (Kafta Humera, Tsegede and Welkait) in 2015 cropping season starting from seedling up to capsule development stages. A total of 48 farm plots was assessed for prevalence, incidence and severity. All surveyed farm plots were infested at all stages of the crop. In the study area incidence of the pest was 66% and 15% capsule damage/severity. Capsule developmental stage of the crop was the most infested crop growth stage in the surveyed Original Research Article
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Sesame webworm (Antigastra catalaunalis) is the major pest, which is causing heavy losses in Humera areas, northern Ethiopia. The present study aims to determine schedule of insecticide application for control of the pest. An experiment... more
Sesame webworm (Antigastra catalaunalis) is the major pest, which is causing heavy losses in Humera areas, northern Ethiopia. The present study aims to determine schedule of insecticide application for control of the pest. An experiment with a randomized complete block design (RCBD) was conducted at Humera Agricultural Research Center to evaluate nine insecticide application schedules. Result of the experiment indicated that weekly spray (S9) resulted in lower webworm incidence (19.5%) and better grain yield (536.6 kg/ha); and highest incidence (99.27%) and lowest grain yield (154.9 kg/ha) was recorded from control. Maximum level of leaf and flower was scored on control and once sprayed plots, while the lowest was on the frequently sprayed. In conclusion, twice application of insecticide at 2 and 4 weeks after emergence was found better for controlling A. catalaunalis.
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Land degradation, mainly due to soil erosion and nutrient losses, is a global problem for sustainable agriculture. Farmlands in the Ethiopian highlands are susceptible to water erosion because of steep slopes and extensive cultivation. A... more
Land degradation, mainly due to soil erosion and nutrient losses, is a global problem for sustainable agriculture. Farmlands in the Ethiopian highlands are susceptible to water erosion because of steep slopes and extensive cultivation. A field experiment was conducted in the Gule sub‐watershed in northern Ethiopia to assess the efficacy of in situ water harvesting techniques in reducing soil and nutrient losses. The research was carried out on a sandy clay loam soil under semi‐arid conditions. Soil erosion and nutrient losses were monitored during the rainy season (June to September) in 2013 and 2014. Five treatments with tied ridges, wheat‐straw mulch and effective microorganisms, alone or in combination, and an untreated control were tested. Combined tied ridges and straw mulch, with and without effective microorganisms, significantly reduced average soil loss over the two rainy seasons by 82 and 90% respectively compared with the control. Tied ridges alone reduced average soil lo...
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Inter-cell interference is the main performance limiting factor in the dense deployment of small cells targeted by the upcoming 5th Generation (5G) radio access technology. In this paper, we present an experimental evaluation of... more
Inter-cell interference is the main performance limiting factor in the dense deployment of small cells targeted by the upcoming 5th Generation (5G) radio access technology. In this paper, we present an experimental evaluation of inter-cell interference mitigation techniques in a real indoor office deployment with four cells, where each cell features one Access Point (AP) and one User Equipment (UE). In particular, we compare traditional Frequency Reuse Planning (FRP) with the recently proposed Maximum Rank Planning (MRP) technique, which relies on the degrees of freedom offered by the multi-antenna transceivers for suppressing a number of interfering streams. Different receiver types are also considered, namely Interference Rejection Combining (IRC) and the interference unaware Maximum Ratio Combining (MRC). Each node in our software defined radio (SDR) testbed features a 2 x 2 MIMO transceiver built with the USRP N200 hardware by Ettus Research. The experimental results in a fully loaded network reveal the capability of the MRP technique to achieve higher throughput performance than FRP for 90% of the cases when IRC receivers are used. Lower network loads lead to further performance improvements for MRP.
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The Interference Rejection Combining (IRC) receiver can significantly boost the network throughput in scenarios characterized by dense uncoordinated deployment of small cells, as targeted by future 5th generation (5G) radio access... more
The Interference Rejection Combining (IRC) receiver can significantly boost the network throughput in scenarios characterized by dense uncoordinated deployment of small cells, as targeted by future 5th generation (5G) radio access technology. This paper presents an experimental study on the potential benefit of IRC receiver in real deployment scenarios. The study is carried out using a software defined radio (SDR) testbed network with four cells, each featuring one Access Point (AP) and one User Equipment (UE) with two antennas. The testbed network was placed in an indoor office and open hall scenarios, respectively. In each scenario, the cells were arranged to characterize the propagation in different spatial configurations. Using the obtained propagation data, we analysed the cases of closed and open subscriber group for the respective scenarios, to compare the achievable throughput with IRC and Maximum Ratio Combining (MRC) receivers. Different frequency reuse schemes were also considered. The throughput results confirm the effectiveness of the IRC receiver in improving the network throughput with respect to the MRC receiver, under the assumption of single stream (rank 1) transmission. Results show average gains up to around 40% and outage gains up to 70% over the MRC receiver. The combination of the IRC receiver and frequency reuse achieves a favourable trade-off between the network throughput and fairness. Overall, due to the direct propagation, the open hall open subscriber group scenario is benefiting the most from the ability of the IRC receiver to cancel a strong dominant interferer.
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Network synchronization is a fundamental enabler of interference mitigation techniques that are required in ultradense deployment of small cells as targeted by upcoming 5th Generation (5G) wireless system. In this paper, we experimentally... more
Network synchronization is a fundamental enabler of interference mitigation techniques that are required in ultradense deployment of small cells as targeted by upcoming 5th Generation (5G) wireless system. In this paper, we experimentally evaluate the possibility of acheiving in a distributed manner (i.e. without any external high precision reference clocks) a tight time alignment in a network of small cells. We are considering a software defined radio (SDR) network of 8 nodes, where each node adopts the Universal Software Radio Peripheral N200 (USRP N200) radio boards by Ettus Research, and the ASGARD software platform. Experimental results demonstrate the possibility of synchronizing the timing of the multiple nodes with a few μs precision, despite of the occurrencies of beacon losses.
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Background Despite the potential impact on treatment adherence and recovery, there is a dearth of data on the extent and correlates of internalized stigma in patients with schizophrenia in low income countries. We conducted a study to... more
Background Despite the potential impact on treatment adherence and recovery, there is a dearth of data on the extent and correlates of internalized stigma in patients with schizophrenia in low income countries. We conducted a study to determine the extent, domains and correlates of internalized stigma amongst outpatients with schizophrenia in Ethiopia. Methods The study was a cross-sectional facility-based survey conducted at a specialist psychiatric hospital in Addis Ababa, Ethiopia. Consecutive consenting individuals with a diagnosis of schizophrenia were recruited and assessed using an Amharic version of the Internalized Stigma of Mental Illness (ISMI) scale. Results Data were collected from 212 individuals, who were mostly single (71.2%), unemployed (70.3%) and male (65.1%). Nearly all participants (97.4%) expressed agreement to at least one stigma item contained in the ISMI; 46.7% had a moderate to high mean stigma score. Rural residence (OR = 5.67; 95% CI = 2.30, 13.00; p <...