Search

Autonomous teams of unmanned ground and air vehicles rely on networking and distributed processing to collaborate as they jointly localize, explore, map, and learn in sometimes difficult and adverse conditions. Co-designed intelligent wireless networks are needed for these autonomous mobile agents for applications including disaster response, logistics and transportation, supplementing cellular networks, and agricultural and environmental monitoring. In this paper we describe recent progress on wireless networking and distributed processing for autonomous systems using a low frequency portion of the electromagnetic spectrum, here defined as roughly 25 to 100 MHz with corresponding wavelengths of 3 to 12 meters. This research is motivated by the desire to support autonomous systems operating in dense and cluttered environments by harnessing low frequency propagation, where meters long wavelengths yield significantly reduced scattering and enhanced penetration of obstacles and structures. This differs considerably from higher frequency propagation, requiring different low frequency propagation models than those widely employed for other bands. Progress in use of low frequency for autonomous systems has resulted from combined advances in low frequency propagation modeling, networking, antennas and electromagnetics, geolocation, multi-antenna array distributed beamforming, and mobile collaborative processing. This article describes the breadth and the depth of interaction between areas, leading to new tools and methods, especially in physically complex indoor/outdoor, dense urban, and other challenging scenarios. We bring together key results, models, measurements, and experiments that describe the state of the art for new uses of low frequency spectrum for multi-agent autonomy.

IntroductionThe increasing pressure on land and water resources, fueled by high population growth and climate change, has profound implications for crop yield and quality. While studies thrive for various crops, a notable research gap exists in understanding the responses of forage crops to irrigation and nutrient management in developing countries. This study aims to address this gap by assessing the impact of irrigation and fertilizer application on forage production in the Ethiopian sub-humid highlands.MethodsThe experiment focused on four forage varieties, namely Napier grass (Cenchrus purpureus) cultivars, ILRI-16791, ILRI-16819, ILRI-16803, and Guinea grass (Megathyrsus maximus) ILRI-144 cultivated in experimental plots. Three irrigation levels designated as IR60 (60% of total available soil water), IR80 (80%), and IR100 (100%) were applied, along with three fertilizer rates: organic manure at 30 t ha−1, and Urea-N at 100 kg ha−1 and 300 kg ha−1. Agronomic data including growth performance, forage dry matter yield, and nutritional quality were collected during two trial years.Results and discussionAmong the various irrigation treatments, IR80 demonstrated the most favorable balance between forage yield, WUE, net benefit, and LWP. In addition, the highest DMY, WUE, net benefit, and LWP were obtained for UREA at the rate of 300 kg ha−1 while the lowest DMY and WUE were observed for UREA at the rate of 100 kg ha−1. Significant variations were observed among the four forage varieties, with Napier grass ILRI-16791 having the highest DMY (9.8 tons ha−1), WUE (39 kg ha−1 mm−1), LWP (0.28 USD m−3 for local cows, and 1.04 USD m−3 for crossbred cows), and net benefit (783 USD ha−1). For all forages combined, a 40 and 20% decrease in irrigation increased water use efficiency by 17 and 9.4%, respectively. These results indicate that a moderate level of deficient irrigation such as IR80 could be a viable water management strategy for irrigated forage, especially in water-scarce areas. The conserved water saved from the deficit irrigation can thus be used to irrigate additional land, contributing to a more sustainable and efficient water usage approach.

Small-scale cultivation of irrigated fodder is emerging as a vital production system in mixed farming communities. Efficient water management plays a key role in enhancing forage production, especially in the face of changing climate. A field-scale experimental study was conducted in Robit Bata kebele, Ethiopia, with the following objectives: (1) to examine the effects of conventional farmers’ irrigation scheduling versus climate-based irrigation scheduling; and (2) to assess the influence of water-lifting technologies (manual pulley and solar Majipump) on dry matter yield (DMY), water productivity (WP), irrigation labor productivity (ILP), and water productivity in terms of crude protein and metabolizable energy (WP.CP and WP.ME) of Napier grass. The experiment used 10 farmers’ plots each with a size of 100 m2. Half of the plots were treated using farmers’ scheduling while the other half were treated using climate-based irrigation scheduling. Monitoring of irrigation water use and crop yield took place over two irrigation seasons from November 2020 to June 2021. Results showed there was an interaction effect of irrigation management (p = 0.019) and water-lifting technologies (p = 0.016) with season on DMY. The highest DMY occurred in the first irrigation season with climate-based scheduling and solar Majipump use. The interaction effect of irrigation management and season affected WP (p = 0.047). Climate-based scheduling had a higher WP in the first season, while farmers’ scheduling had a higher WP during the second season. On average, the solar Majipump outperformed the pulley, achieving 5 kg m−3 WP compared to the pulley’s 4 kg m−3 (p = 0.018). Emphasizing the seasonal impact, it is recommended to promote full irrigation (climate-based) in the first season for maximum yield and WP. Conversely, in the second season, advocating only deficit irrigation is advised due to water scarcity and sustainability concerns. Statistical parity in DMY and lower WP with full irrigation in the second season supports this recommendation, addressing the challenge of optimizing water use in the context of a changing climate and ensuring sustainable smallholder agriculture practices. Therefore, implementing appropriate irrigation management alongside efficient water-lifting technologies holds the potential to enhance fodder productivity and bolster smallholder farmers’ livelihoods. Future research should explore the comparative benefits of irrigated fodder versus other crops and the overall advantages of investing in irrigated fodder over vegetables.

Tesfahun Zewde Legisso,1 Bereket Getachew Mamo,1 Abebaw Miskir Bimrew,1 Teshale Fikadu2,3 1Department of Statistics, College of Natural Sciences, Arba Minch University, Arba Minch, Ethiopia; 2Department of Public Health, College of Medicine and Health Science, Arba Minch University, Arba Minch, Ethiopia; 3Department of Nutrition and Dietetics, Faculty of Public Health, Institute of Health, Jimma University, Jimma, EthiopiaCorrespondence: Tesfahun Zewde Legisso, Email tesfahun.zewde@yahoo.comBackground: Hypertension is a common non-communicable disease detected through blood pressure measurement that makes periodic health examinations crucial for the detection, prevention, and timely treatment.Objective: To assess the frequency of blood pressure examination and its determinant among civil servants in Arba Minch Town, south Ethiopia.Methods: From February to March 2020 an organization-based cross-sectional study design was employed among civil servants in Arba Minch town. Data were collected from 580 randomly selected civil servants using a well-structured questionnaire. Hurdle Poisson regression model was conducted to identify determinants of frequency of blood pressure examination using R version 4.0.2.Results: A total of 407 (70.2%) civil servants had never examined their blood pressure within a year before the study time. The mean frequency of blood pressure examination was 0.71 with a standard deviation of 1.46. The hurdle Poisson regression analysis indicates age above 40 years (IRR = 6.11, p < 0.001), elevated blood pressure (IRR = 1.48, p < 0.001), no family history of hypertension (IRR = 0.59, p < 0.001) had significant effects on the expected number of non-zero counts blood pressure examination. And education status (OR; 2.39, p < 0.05), poor knowledge about hypertension, not getting advice from health professionals (OR = 8.93, p < 0.001), and age above 40 years had significant effects on not taking blood pressure examination.Conclusion: The frequency of blood pressure examinations among civil servants was found to be low. This study reveals age, elevated blood pressure, family history of hypertension, getting advice, and knowledge on hypertension were found to be determinants of the frequency of blood pressure examination. Thus, concerned health authorities and medical workers should work on these factors to prevent and detect hypertension among apparently healthy civil servants.Keywords: Arba Minch, blood pressure examination, Ethiopia, hurdle Poisson regression, hypertension

This paper presents a compact three-port antenna design suitable for use in mobile radio systems that require polarization and pattern diversity. The antenna design utilizes a shorted bow-tie patch split in half with an air gap and a top-loaded two-element monopole placed along the gap on a small common ground plane ( $0.37\lambda ^{2}$ ) to achieve a compact form factor. The patch is excited by aperture coupling and probe feeding via two independent ports, producing two orthogonally polarized broadside patterns for polarization diversity. Meanwhile, the co-located monopole generates a vertically polarized omnidirectional pattern to provide pattern diversity. High inter-port isolation (> 25 dB) is achieved by incorporating simple decoupling structures shorted to the ground plane between the patch and the monopole. Measurements on the antenna prototype show that envelope correlation coefficients among the three different radiation patterns are lower than – 37 dB (or 0.0002) within the operating bandwidth, making this antenna a good candidate for diversity applications.

Negussie Boti Sidamo,1 Sultan Hussen,1 Tamiru Shibiru,2 Meseret Girma,1 Mulugeta Shegaze,1 Abera Mersha,3 Teshale Fikadu,1 Zeleke Gebru,1 Eshetu Andarge,1 Mustefa Glagn,1 Selamawit Gebeyehu,1 Bilcha Oumer,4 Gebremaryam Temesgen5 1School of Public Health, College of Medicine and Health Sciences, Arba Minch University, Arba Minch, Ethiopia; 2School of Medicine, College of Medicine and Health Sciences, Arba Minch University, Arba Minch, Ethiopia; 3School of Nursing, College of Medicine and Health Sciences, Arba Minch University, Arba Minch, Ethiopia; 4Department of Midwifery, College of Health Sciences, Arba Minch, Ethiopia; 5Department of Midwifery, College of Medicine and Health Sciences, Arba Minch University, Arba Minch, EthiopiaCorrespondence: Negussie Boti SidamoSchool of Public Health, College of Medicine and Health Sciences, Arba Minch University, Arba Minch, EthiopiaEmail Hanehalid@gmail.comBackground: Since the occurrence of the COVID-19 pandemic, different public health measures have been implemented to prevent and control the further spread of the disease. However, barriers that influence the effective implementation of public health measures were not explore in Ethiopia especially in study Area. Therefore, this study tried to fill this gap by exploring the barriers to effective implementation of public health measures for prevention and control of the COVID-19 pandemic in the Gamo Zone of southern Ethiopia.Methods: The study employed a qualitative study with a phenomenology approach among purposely selected 30 individuals in the community and selected institutions. Key informant interview was used to collect the data. The data were transcribed verbatim and translated into the English language. The transcribed data were read several times to clearly understand the content for further analysis. The analysis of the data was conducted based on the modified Tanahashi framework.Results: The study identified different barriers under five main themes: accessibility, acceptability, availability, contact and use, and effective implementation of public health measures related to barriers. The main barriers to effective implementation of public health measures were resistance to change, negligence, lack of community engagement, insufficient training for front line workers, poor supportive supervision, poor law enforcement, and lack of continuous community awareness creation. Beside, acceptability related barriers like cultural and religious norms and availability related barriers like shortage of personal protective equipment and shortage of skilled health professional have also lion share barriers for implementation of the public health measures.Conclusion: The study identified different personal, institutional, and societal level barriers for effective implementation of public health measures for the COVID-19 pandemic. Therefore, proper and targeted continuous community awareness creation with further mandatory law enforcement activities should be implemented by the concerned bodies to mitigate individual and societal level barriers. In addition, the government with relevant stakeholders should give due attention to equip and protect the frontline professionals by availing the necessary logistic and provision of continuous capacity-building activities.Keywords: COVID-19, effective implementation, public health measures, modified Tanahashi model, barriers, Gamo zone

Eshetu Andarge,1 Teshale Fikadu,1 Rodas Temesgen,2 Mulugeta Shegaze,1 Tesfaye Feleke,1 Firehiwot Haile,1 Gisila Endashaw,3 Negussie Boti,1 Alemayehu Bekele,4 Mustefa Glagn1 1School of Public Health, Arba Minch University, Arba Minch, Southern Nations Nationalities and Peoples Regional State, Ethiopia; 2Department of Internal Medicine, School of Medicine, Arba Minch University, Arba Minch, Southern Nations Nationalities and Peoples Regional State, Ethiopia; 3School of Nursing, Arba Minch University, Arba Minch, Southern Nations Nationalities and Peoples Regional State, Ethiopia; 4Center for Neglected Tropical Diseases, Arba Minch University, Arba Minch, Southern Nations Nationalities and Peoples Regional State, EthiopiaCorrespondence: Eshetu AndargeSchool of Public Health, Arba Minch University, P.O. Box: 021, Arba Minch, Southern Nations Nationalities and Peoples Regional State, EthiopiaTel +251-9-45-89-59-37Email andeshe7@gmail.comPurpose: With prevention being the only and best available intervention, COVID-19 has recently become a global threat, having had and continuing to have enormous health, economic, and societal impacts. Evidence so far has documented a heightened risk of mortality to people with chronic conditions. There is a dearth of evidence regarding chronic disease patients’ intention and practice on the preventive measures. This study tried to fill this gap by assessing the intention to practice and practice on personal preventive measures (PPMs) among adults with chronic conditions.Materials and Methods: A facility-based cross-sectional study was conducted in Southern Ethiopia among 806 adults with chronic conditions by employing a multistage sampling technique. Data were collected using a pre-tested and structured questionnaire. Statistical analysis was done using IBM SPSS software version 25. Binary logistic regression analysis was done to identify factors associated with intention and practice. Level of statistical significance was declared at a P-value of less than 0.05.Results: The study showed that 52% (95% CI=47.61– 54.80) and 76.3% (95% CI=73.36– 79.24) of adults with chronic conditions were intending to practice and had ever practiced the personal preventive measures. Participants’ subjective norm (SN) (AOR=4.94; 95% CI=3.49– 6.96) and perceived behavioral control (PBC) (AOR=4.13; 95% CI=2.69– 6.34) were the factors associated with their intention. Good knowledge and a positive attitude were found to be significant factors associated with the participants’ actual practice of the PPMs among other independent factors.Conclusion: Around half of the participants were intending to practice PPMs, and three-quarters had good practice on the PPMs against COVID-19. Interventions targeted to improve intention and practice on the PPMs need to take into account improving knowledge and attitude, and build positive subjective norms and heighten the confidence to control the preventive behaviors.Keywords: intention, practice, theory of planned behavior, chronic conditions, South Ethiopia

In this paper, we study a wireless network where multiple distributed transmitters control the phases of their signals so that they can be constructively combined at a client receiver. Unlike centralized beamforming with co-located and phase-synchronized antennas, geographically separated transmitters experience phase offsets caused by the individual local oscillators. In practical scenarios, the transmitters should not be placed too close to each other in order to alleviate mutual coupling effects and extend the coverage region. In this regard, we model the spatial distribution of the transmitters as a β -Ginibre point process that models the repulsive feature. We investigate two types of transmission strategies: (i) Transmitter selection in which the client selects the transmitter providing the highest received power at the client, and (ii) Coherent beamforming in which multiple transmitters send their signals simultaneously to the client in the presence of phase offsets among the transmitters. We introduce the exact expression of the coverage probability of the transmitter selection method. Also, we derive an approximation of the coverage probability of the coherent beamforming scheme by leveraging two scaling factors that respectively capture the impacts of the phase offsets and the degree of repulsion on the coverage probability. From numerical simulations, we validate the accuracy of our analysis.

The study was conducted to determine the yield and nutritional quality of sweet lupine (Lupinus angustifolius.) grown in midaltitude of Lemo District, Southern Ethiopia. The yield and nutritive value of sweet lupine in terms of quantity and quality was conducted using a factorial experiment arranged in a randomized complete block design (RCBD) with three replications. The treatments for the study were two sweet lupine varieties (Vitabore and Sanabore), two locations (Upper Gana and Jewe Kebeles, and six levels of planting spacing: 30 cm × 7 cm (S1), 40 cm × 7 cm (S2), 30 cm × 15 cm (S3), 40 cm × 15 cm (S4), 30 cm × 20 cm (S5), and 40 cm × 20 cm (S6)). The yield, chemical composition, and digestibility among parameters were studied. Sweet lupine varieties in Upper Gana Kebele gave the highest green forage yield (39.58 t/ha) and forage dry matter (4.84 t/ha) at 30 cm × 7 cm planting spacing, respectively. Seed yield (SYD) (t/ha) was highly affected (P

This article is meant to analyze the origin, evolution and current status of neoliberalism with special focus on the shift that has been observed in the main-stream political ideology of capitalism. An explanatory research approach was employed by relying on secondary sources of data to explain the rise and fall of neoliberalism and its dynamics and uncertain journey in an allegory of destruction of the Berlin Wall to the construction of Mexico wall. The review revealed that the neoliberal ideology which was once projected as a panacea for the liberation of human dignity, autonomy, choice, voluntary exchange, freedom to compete in markets and personal empowerment is no more relevant and workable as it was during the 1970s. The shreds of evidence further brought out that champions of neoliberalism were more engaged in the arms race, religious polarization, terrorism vs. anti-terrorism, mainstream ideological rivalry, politics of oil under the garb of democracy and market economy. A paradigm shift was also observed as a hallmark in this paper when the messiah of neoliberalism shifted to protectionism which is symbolized by the strong zeal to construct the Mexico Wall. This paradigm shift took place now when free-trade ideology started to signify a trend of integration among the countries of the South and when a significant rise of Emerging Markets has been taking place. It concluded that the holiness of market-oriented ideology proved to be an unholy affair.

A low-power, low-frequency, ad hoc networking paradigm is considered for robust communications among mobile agents in complex non-line-of-sight (NLOS) indoor and urban-type scenarios. Compared with higher frequency, the lower portion of the very high frequency (VHF) band offers improved penetration and reduced multipath in such scenarios. Low VHF is underutilized for mobile ad hoc networking due to the lack of compact low-power systems and efficient miniature antennas. We investigate the proposed approach through experiments in realistic scenarios. In order to carry out the experiments, we leverage a compact, low-power ZigBee radio operating seamlessly in the low-VHF band by introducing a bi-directional frequency converter, which translates ZigBee signals into low-VHF carriers, along with a recently developed highly miniaturized efficient antenna. The experimental low-VHF radio system and a conventional ZigBee operating at 2.4 GHz are both integrated on a compact ground robotic platform for autonomous experimentation and comparison in NLOS indoor and outdoor settings. Measurements quantify the significant advantages of the low-VHF radio system in terms of packet error rate, fading, radio signal strength, and extended spatial coverage, in a number of complex communication environments.

Introduction: The increasing pressure on land and water resources, fueled by high population growth and climate change, has profound implications for crop yield and quality. While studies thrive for various crops, a notable research gap exists in understanding the responses of forage crops to irrigation and nutrient management in developing countries. This study aims to address this gap by assessing the impact of irrigation and fertilizer application on forage production in the Ethiopian sub-humid highlands. Methods: The experiment focused on four forage varieties, namely Napier grass (Cenchrus purpureus) cultivars, ILRI-16791, ILRI-16819, ILRI-16803, and Guinea grass (Megathyrsus maximus) ILRI-144 cultivated in experimental plots. Three irrigation levels designated as IR60 (60% of total available soil water), IR80 (80%), and IR100 (100%) were applied, along with three fertilizer rates: organic manure at 30 t ha-1, and Urea-N at 100kgha-1 and 300kgha-1. Agronomic data including growth performance, forage dry matter yield, and nutritional quality were collected during two trial years. Results and discussion: Among the various irrigation treatments, IR80 demonstrated the most favorable balance between forage yield, WUE, net benefit, and LWP. In addition, the highest DMY, WUE, net benefit, and LWP were obtained for UREA at the rate of 300kgha-1 while the lowest DMY and WUE were observed for UREA at the rate of 100kgha-1. Significant variations were observed among the four forage varieties, with Napier grass ILRI-16791 having the highest DMY (9.8 tons ha-1), WUE (39kgha-1 mm-1), LWP (0.28 USD m-3 for local cows, and 1.04 USD m-1 for crossbred cows), and net benefit (783 USD ha-1). For all forages combined, a 40 and 20% decrease in irrigation increased water use efficiency by 17 and 9.4%, respectively. These results indicate that a moderate level of deficient irrigation such as IR80 could be a viable water management strategy for irrigated forage, especially in water-scarce areas. The conserved water saved from the deficit irrigation can thus be used to irrigate additional land, contributing to a more sustainable and efficient water usage approach. [ABSTRACT FROM AUTHOR]

Small-scale cultivation of irrigated fodder is emerging as a vital production system in mixed farming communities. Efficient water management plays a key role in enhancing forage production, especially in the face of changing climate. A field-scale experimental study was conducted in Robit Bata kebele, Ethiopia, with the following objectives: (1) to examine the effects of conventional farmers' irrigation scheduling versus climate-based irrigation scheduling; and (2) to assess the influence of water-lifting technologies (manual pulley and solar Majipump) on dry matter yield (DMY), water productivity (WP), irrigation labor productivity (ILP), and water productivity in terms of crude protein and metabolizable energy (WP.CP and WP.ME) of Napier grass. The experiment used 10 farmers' plots each with a size of 100 m2. Half of the plots were treated using farmers' scheduling while the other half were treated using climate-based irrigation scheduling. Monitoring of irrigation water use and crop yield took place over two irrigation seasons from November 2020 to June 2021. Results showed there was an interaction effect of irrigation management (p = 0.019) and water-lifting technologies (p = 0.016) with season on DMY. The highest DMY occurred in the first irrigation season with climate-based scheduling and solar Majipump use. The interaction effect of irrigation management and season affected WP (p = 0.047). Climate-based scheduling had a higher WP in the first season, while farmers' scheduling had a higher WP during the second season. On average, the solar Majipump outperformed the pulley, achieving 5 kg m−3 WP compared to the pulley's 4 kg m−3 (p = 0.018). Emphasizing the seasonal impact, it is recommended to promote full irrigation (climate-based) in the first season for maximum yield and WP. Conversely, in the second season, advocating only deficit irrigation is advised due to water scarcity and sustainability concerns. Statistical parity in DMY and lower WP with full irrigation in the second season supports this recommendation, addressing the challenge of optimizing water use in the context of a changing climate and ensuring sustainable smallholder agriculture practices. Therefore, implementing appropriate irrigation management alongside efficient water-lifting technologies holds the potential to enhance fodder productivity and bolster smallholder farmers' livelihoods. Future research should explore the comparative benefits of irrigated fodder versus other crops and the overall advantages of investing in irrigated fodder over vegetables. [ABSTRACT FROM AUTHOR]