The Role of Harvest Index in Improving Crop Productivity: A Review

Harvest index (HI) is a measure of success in partitioning assimilated photosynthate. An improvement of crop harvest index means an increase in the economic portion of the crops in certain level. HI is a novel trait which contributed significant role in improvement of crop productivity which could solve the problem of food supplies for the rapidly increasing population. The objective of this paper was to review the role and progress of HI in improving crop productivity.  Although crop HI influenced by both environmental and genetic factors, the progress improvement of HI and yield through crop management technique and breeding method strategy is an anticipative. In addition, the knowledge of genetic mode of expression of HI provides information for breeder to determine next breeding method. Keywords: Additive, Environmental, Genetic, Harvest index, non additive, productivity DOI: 10.7176/JNSR/9-6-04 Publication date:March 31st 201

Hybrid Vigour Study of Yield and Yield Related Characters on Limmu Coffee (Coffea arabica L.) Genotypes at South-Western Ethiopia

Coffee (Coffea arabica L.) is one of the most important crops cultivated worldwide and has a great economic impact in many countries including Ethiopia. Hybrid vigor (heterosis) breeding can enhance productivity of coffee. Hybrid vigor study was conducted on 5 x 5 half-diallel mating involving 17coffee genotypes (5 parents, 10 F1 hybrids and two checks) for yield and its related traits in 2018. The study locations include Jimma, Agaro and Gera research centers of south-western Ethiopia using randomized completely block design with three replications. There are significant differences among 17 genotypes and 15 diallel genotypes (checks excluded) for all traits; the crosses showed significant and positive average heterosis (mid parent) and heterobeltiosis (better parent) for all traits. Crosses showed significant variation in the expression of standard heterosis (SH) and useful heterosis (UH) for fruit length (FL), fruit width (FW), bean length (BL), bean width (BW), bean thickness(BT), and hundred bean weight (HBW) across locations. Heterobeltiosis ranged from -9.06 to 88.79% and -17.81 to 67.98% for yield at Jimma and Gera, respectively. Mean SH and UH was positive and between 5 and 10% for BL and BT and <5% for all fruit characters and BT across locations. Mean of SH and UH was 14.62% and 11.82%, respectively for HBW. Crosses P4 x P5, P1 x P5 and P2 x P5 increased yield by 25.13% (637.75 kg), 14.05% (356.64 kg) and 5.78% (146.59 kg) over commercial pure line variety across three locations, respectively. Based on heterosis and mean performance hybrids P4 x P5, P1 x P5, P3 x P5, and P1 x P2 found as promising hybrids for yield and bean characters. Thus, these hybrids should be advanced in the next breeding program and tested through incorporating other traits

Plant Population Density and N Rate Influence the Growth and Seed Producibility of Intermediate Maturing Maize Parental Line at Sub-humid Agro-Ecology of Western Oromia, Ethiopia

At the study location of Bako National Maize Research Center, the experiment was carried out on BKL004 maize inbred line in 2019 to 2021 cropping season. The goal of this experiment was to determine an optimum plant population density and N rate on the BKL004 maize parental line. The experiment had two factors: five levels of plant population densities (44,444, 53,333, 66,666, 88,888 and 133,333 plants ha‑1) and four levels of nitrogen (111, 157, 203, and 249 kg ha‑1). The experiment included a total of twenty treatments (4*5) that were distributed in a factorial arrangement using an RCBD design. Each treatment was repeated three times. Different BKL004 maize parental line growth, phonological, and yield characteristics were gathered. Also, partial budget analysis were done to identify the most profitability treatment. Plant population density exerted a significant (p<0.05) effect on plant height, ear height, girth, days to 50% female flowering and seed yield. The tallest plant and ear height were recorded at plant population density of 133,333 plants ha‑1 with average plant and ear height of 146.50 cm and 61.32 cm respectively. The maximum girth (17.47) was obtained at 53, 333 plant population ha‑1. The highest plant population density extends the appearance of 50% days to silking by 91.72 days. The highest seed yield (3307 kg ha‑1) was recoded at plant population of 133,333 plants ha‑1, followed by seed yield recorded at plant population of 88,888 plants ha-1. N at the rate of 249 kg ha-1 with 133,333 plants ha‑1 was the most economically profitable than all the other treatments, followed by economic return obtained at 88,888 plants ha‑1 with 157 kg ha‑1 of N rate. However, as plant population affect the size of seed it may affect the seed germination and seedling vigor. Thus, 88.888 plants ha‑1 with 157 kg ha‑1 N rate was recommended for seed producer

Genetic Purity Analysis of Maize (Zea mays L.) Hybrid Seed and Their Parents Produced in Different Seed Companies of Ethiopia

Genetic purity is one of the quality criteria required for successful seed production of maize. In hybrid seed production, genetic purity is contaminated due to out-crossing from other varieties or selfing events. In this study, Single nucleotide Polymorphisms (SNP) and Grow-out test (GOT) method was used for the objective to assess genetic purity of maize hybrid varieties with their parents produced by various seed growers in the country. Six three way cross hybrid (3WCH) maize varieties and seven single crosses were collected from different sources then planted with their parents in 2019. Genetic purity analysis by SNP revealed that 74% of an inbred line showed an acceptable genetic purity level (>95%). However, five inbred lines (CML395, A7033, F7215, SC22 and 124-b(113)) revealed heterogeneity >0.05 ranged from 0.13 to 0.20. All single crosses except A7033/F7215 and all the 3WCH varieties showed the genetic purity level ranging from 40 to 66% and 44 to 63% across seed sources, respectively. Based on GOT results, the level of type in single crosses and 3WCH variety across seed sources ranged from 7.1 to 46.4% and 3.6 to 35.7%, respectively. Generally, in the current result both SNP and GOT showed both heterogeneity and homogeneity of seed. This implies the presence of variation among seed producers in terms of producing high quality seed. Therefore, awareness should have to be given for each individual seed producers on quality seed production techniques and procedures that they have to follow. Similarly, genetic purity analysis could be conducted further in the seed system to provide error correction and to ensure seed quality assurance and control

Global, regional, and national under-5 mortality, adult mortality, age-specific mortality, and life expectancy, 1970–2016: a systematic analysis for the Global Burden of Disease Study 2016

BACKGROUND: Detailed assessments of mortality patterns, particularly age-specific mortality, represent a crucial input that enables health systems to target interventions to specific populations. Understanding how all-cause mortality has changed with respect to development status can identify exemplars for best practice. To accomplish this, the Global Burden of Diseases, Injuries, and Risk Factors Study 2016 (GBD 2016) estimated age-specific and sex-specific all-cause mortality between 1970 and 2016 for 195 countries and territories and at the subnational level for the five countries with a population greater than 200 million in 2016. METHODS: We have evaluated how well civil registration systems captured deaths using a set of demographic methods called death distribution methods for adults and from consideration of survey and census data for children younger than 5 years. We generated an overall assessment of completeness of registration of deaths by dividing registered deaths in each location-year by our estimate of all-age deaths generated from our overall estimation process. For 163 locations, including subnational units in countries with a population greater than 200 million with complete vital registration (VR) systems, our estimates were largely driven by the observed data, with corrections for small fluctuations in numbers and estimation for recent years where there were lags in data reporting (lags were variable by location, generally between 1 year and 6 years). For other locations, we took advantage of different data sources available to measure under-5 mortality rates (U5MR) using complete birth histories, summary birth histories, and incomplete VR with adjustments; we measured adult mortality rate (the probability of death in individuals aged 15-60 years) using adjusted incomplete VR, sibling histories, and household death recall. We used the U5MR and adult mortality rate, together with crude death rate due to HIV in the GBD model life table system, to estimate age-specific and sex-specific death rates for each location-year. Using various international databases, we identified fatal discontinuities, which we defined as increases in the death rate of more than one death per million, resulting from conflict and terrorism, natural disasters, major transport or technological accidents, and a subset of epidemic infectious diseases; these were added to estimates in the relevant years. In 47 countries with an identified peak adult prevalence for HIV/AIDS of more than 0·5% and where VR systems were less than 65% complete, we informed our estimates of age-sex-specific mortality using the Estimation and Projection Package (EPP)-Spectrum model fitted to national HIV/AIDS prevalence surveys and antenatal clinic serosurveillance systems. We estimated stillbirths, early neonatal, late neonatal, and childhood mortality using both survey and VR data in spatiotemporal Gaussian process regression models. We estimated abridged life tables for all location-years using age-specific death rates. We grouped locations into development quintiles based on the Socio-demographic Index (SDI) and analysed mortality trends by quintile. Using spline regression, we estimated the expected mortality rate for each age-sex group as a function of SDI. We identified countries with higher life expectancy than expected by comparing observed life expectancy to anticipated life expectancy on the basis of development status alone. FINDINGS: Completeness in the registration of deaths increased from 28% in 1970 to a peak of 45% in 2013; completeness was lower after 2013 because of lags in reporting. Total deaths in children younger than 5 years decreased from 1970 to 2016, and slower decreases occurred at ages 5-24 years. By contrast, numbers of adult deaths increased in each 5-year age bracket above the age of 25 years. The distribution of annualised rates of change in age-specific mortality rate differed over the period 2000 to 2016 compared with earlier decades: increasing annualised rates of change were less frequent, although rising annualised rates of change still occurred in some locations, particularly for adolescent and younger adult age groups. Rates of stillbirths and under-5 mortality both decreased globally from 1970. Evidence for global convergence of death rates was mixed; although the absolute difference between age-standardised death rates narrowed between countries at the lowest and highest levels of SDI, the ratio of these death rates-a measure of relative inequality-increased slightly. There was a strong shift between 1970 and 2016 toward higher life expectancy, most noticeably at higher levels of SDI. Among countries with populations greater than 1 million in 2016, life expectancy at birth was highest for women in Japan, at 86·9 years (95% UI 86·7-87·2), and for men in Singapore, at 81·3 years (78·8-83·7) in 2016. Male life expectancy was generally lower than female life expectancy between 1970 and 2016, an

Comparaison des performances de signaux multiplexés dans le domaine des fréquences non-linéaires et OFDM pour les transmissions par fibre optique

Nonlinear effects in optical fiber set the ultimate limit to the channel capacity in long-haul optical transmission systems. Advanced nonlinear compensation techniques such as digital backpropagation (DBP) have been proposed as a solution to overcome the channel capacity crunch. However, given theircomputational complexity, in a practical environment their performance gainremains very limited. This triggered a search for a novel communication system design that takes fiber nonlinearity into consideration. A new nonlinearcommunication method, based on the theory of the inverse spectral transform, has been proposed to overcome the nonlinear capacity crunch. Thismethod, originally proposed by Hasegawa in 1993 and called eigenvalue (ormulti-soliton) communication, is based on the fundamental observation thatthe nonlinear spectrum of an optical signal is invariant (except for a triviallinear phase shift) upon propagation in the fiber channel, as described bythe nonlinear Schrödinger equation (NLSE). This means that if the directspectral transform (also known as nonlinear Fourier transform (NFT)) ofthe received signal can be computed, the eigenvalue spectrum can be fullyrecovered.This thesis focuses on a NFT-based communication technique known as nonlinear frequency division multiplexing (NFDM). The NFDM optical systemis numerically assessed and experimentally demonstrated. First, the structure of the proposed single-polarization NFDM system using the continuousspectrum in the normal dispersion regime is presented. To that end, theNFT of the vector NLSE, or Manakov system, was numerically developed.Based on these algorithms the NFDM method was extended to polarizationdivision multiplexed (PMD) systems, and experimentally validated for thefirst time using the continuous spectrum. Finally, the experiment will bereplicated in the anomalous dispersion regime.Additional numerical studies are presented, in order to investigate the implementation challenges of the proposed NFDM techniques for the continuousspectrum modulation.La capacité ultime du canal dans les systèmes de transmission optique à longue distance est limitée par les effets non linéaires liés à la propagation dans les fibres optiques. Des techniques de compensation des effets non-linéaires, tel que la DBP (Digital Back Propagation), ont été proposées pour surmonter ces limitations et accroître la capacité. Compte tenu de leur complexité d’implémentation, leur gain en performance reste très limité. Cela a déclenché très récemment la recherche de nouvelles techniques de communication prenant en compte la non-linéarité de la fibre. Une nouvelle méthode de communication en régime non-linéaire, basée sur la théorie de la transformation spectrale inverse (IST pour Inverse Spectral Transform), a été proposée pour surmonter la limitation induite par ces effets. Cette méthode, proposée à l'origine par Hasegawa en 1993, encore appelée communication aux valeurs propres (ou multi-solitons), est basée sur l'observation fondamentale selon laquelle le spectre non linéaire d'un signal optique est invariant (à l'exception d'un déphasage linéaire trivial) lors de la propagation dans la fibre optique, comme décrit par l’équation non linéaire de Schrödinger (NLSE pour Non-Linear Schrödinger Equation). Cela signifie que si la transformée spectrale directe (DST) (également appelée NFT pour Nonlinear Fourier Transform) du signal reçu peut être calculée, le spectre de valeurs propres peut être entièrement récupéré.Cette thèse porte sur une technique de communication de type NFT connue sous le nom de multiplexage non linéaire en fréquence (NFDM pour Non-Linear Fourier Transform). Différentes configurations de systèmes optiques NFDM ont été évalués numériquement et validés expérimentalement. Dans un premier temps, la structure d’un système NFDM en mono-polarisation utilisant le spectre continu des fréquences non-linéaires dans une fibre en régime de dispersion normale est décrite. Pour ce faire, une forme NFT du vecteur NLSE, encore appelé système de Manakov, a été développé numériquement. Sur la base de ces algorithmes, la méthode NFDM a été étendue aux systèmes multiplexés par division de polarisation (PMD) et validée expérimentalement pour la première fois en utilisant le spectre continu. Finalement, l’expérience a été répliquée en régime de dispersion anormale. Afin d'étudier les contraintes de mise en œuvre, des études numériques supplémentaires ont été effectués pour la transmission de signaux NFDM utilisant la modulation du spectre continu

Efficient second-harmonic generation through cascaded optically poled fibers

We report the experimental demonstration of efficient second-harmonic generation by splicing optically poled fiber segments. A device made from five segments each 20 cm-long exhibits, at a fundamental average power of 4.2 mW, a maximum increase of 5.5 in the conversion efficiency with respect to a single 20 cm poled fiber, corresponding to a conversion efficiency of 5.4%. For any considered fundamental power, the conversion efficiency at the output of a five-segment device is larger than the efficiency of a single poled fiber having the same length

Determinants of implanon discontinuation among women who ever used implanon in Shashemene district, west Arsi zone, Southern Ethiopia: unmatched case control study

Abstract Background Despite tremendous work has been done on demand creation, capacity building and ensuring the logistics of Implanon; its discontinuation rate remained high in Ethiopia; the prevalence is reported to be 31% in Shashemene District. However, the factors contributing to the high prevalence of early Implanon discontinuation were not well understood in our study setting. Objective This study aimed to identify the determinants of implanon discontinuation among women who had ever used Implanon in Shashemene District, Southern Ethiopia. Methods A community-based unmatched case-control study was conducted among randomly selected 264 women (88 cases and 176 controls) in Shashemene District, Southern Ethiopia, from April 12 to May 18, 2021. A systematic random sampling technique was used to select the respondents. Cases were women who discontinued Implanon before 3 years and controls were those who used implanon for 3 full years. A pre-tested, interviewer-administered structured questionnaire was used to collect data. Bivariable and multivariable binary logistic regression analyses were performed to identify determinants of Implanon discontinuation. An odds ratio (OR) with a 95% confidence interval (CI) was used to estimate the strength of the association, and significance was declared at a P value of less than 0.05. Result The mean age of the respondents was 28.23 (± 5.46) years: 27.27 (± 5.38) years for cases and 28.70 (± 5.5) years for controls. Women with no formal education [AOR = 3.09, 95% CI: (1.20, 8.00)], fewer than four children [AOR = 2.47, 95% CI: (1.20, 5.08)], no history of abortion [AOR = 2.84, 95% CI: (1.25, 6.46)], being new acceptors [AOR = 2.14, 95% CI: (1.02, 4. 49)], being counseled for less than fifteen minutes [AOR = 2.47, 95% CI: (1.29, 4.70)], not discussing it with a partner [AOR = 2.88, 95% CI: (1.42, 5.84)] and experiencing side effects [AOR = 0.35, 95% CI: (0.17, 0.71)] were significantly associated with discontinuation of implanon. Conclusion Women with no formal education, having less than four children, history of abortion, new acceptors, duration of counseling, discussion with partner, and side effects were determinants of Implanon discontinuation among women. There is a need to ensure adequate pre-implantation counseling and appropriate management of side effects. Furthermore, interventions should target new acceptors and those without formal education

Indigenous knowledge on the practice of milk container fumigation and its effect on microbial safety of milk among pastoral communities in west Guji zone, southern Ethiopia

Introduction: Milk is a high-risk food and has been implicated in many foodborne illnesses. Thus, the pastoral communities in rural Ethiopia used a traditional practice of milk container fumigation to maintain the quality and safety of milk. Objective: to assess the indigenous knowledge on milk container fumigation practice and its effect on the microbial safety of milk among pastoral communities in the west Guji zone, southern Ethiopia. Methods: A cross-sectional study design was conducted in six randomly selected kebeles of the pastoral districts in the west Guji zone, Southern Ethiopia from December to June/2022. The preservative plants and raw milk samples were collected and transported to the laboratory, to analyze the efficacy of plants on the microbial safety throughout milk storage. A variance analysis was used to compare the means of microbiological growth and pH measure among the treatments and control; while thematic analysis was for qualitative data. Result: Four species of plants, namely: Olea africana, Clerodendrum myricoides (Hochst) vatke, Rhamnus staddo, and Rhus natalensis were identified from the study area; as they were used for fumigating milk storage containers to prevent a contamination of milk. According to respondents, the fumigation of milk containers was practiced by holding the container upside down over the smoke from a burning chip of each plant species. Accordingly, it was demonstrated that the R. staddo has relatively better efficacy in inhibiting microbial growth in milk than O. africana and C. myricoides (Hochst) vatke; while R. natalensis has no significant impact on microbial growth in milk over the storage period. Conclusion: Pastoralists in the West Guji zone were fumigated the milk storage container by using smoke of O. africana, R. staddo, C. myricoides (Hochst) vatke, and R. natalensis plants. As such, it was identified that R. staddo has relatively better efficacy in inhibiting microbial growth in milk than O. africana and C. myricoides (Hochst) vatke; and it is a better plant to be recommended for the preservation of cow milk

Another dengue fever outbreak in Eastern Ethiopia-An emerging public health threat.

BackgroundDengue Fever (DF) is a viral disease primarily transmitted by Aedes (Ae.) aegypti mosquitoes. Outbreaks in Eastern Ethiopia were reported during 2014-2016. In May 2017, we investigated the first suspected DF outbreak from Kabridahar Town, Somali region (Eastern Ethiopia) to describe its magnitude, assess risk factors, and implement control measures.MethodsSuspected DF cases were defined as acute febrile illness plus ≥2 symptoms (headache, fever, retro-orbital pain, myalgia, arthralgia, rash, or hemorrhage) in Kabridahar District residents. All reported cases were identified through medical record review and active searches. Severe dengue was defined as DF with severe organ impairment, severe hemorrhage, or severe plasma leakage. We conducted a neighborhood-matched case-control study using a subset of suspected cases and conveniently-selected asymptomatic community controls and interviewed participants to collect demographic and risk factor data. We tested sera by RT-PCR to detect dengue virus (DENV) and identify serotypes. Entomologists conducted mosquito surveys at community households to identify species and estimate larval density using the house index (HI), container index (CI) and Breteau index (BI), with BI≥20 indicating high density.ResultsWe identified 101 total cases from May 12-31, 2017, including five with severe dengue (one death). The attack rate (AR) was 17/10,000. Of 21 tested samples, 15 (72%) were DENV serotype 2 (DENV 2). In the case-control study with 50 cases and 100 controls, a lack of formal education (AOR [Adjusted Odds Ratio] = 4.2, 95% CI [Confidence Interval] 1.6-11.2) and open water containers near the home (AOR = 3.0, 95% CI 1.2-7.5) were risk factors, while long-lasting insecticide treated-net (LLITN) usage (AOR = 0.21, 95% CI 0.05-0.79) was protective. HI and BI were 66/136 (49%) and 147 per 100 homes (147%) respectively, with 151/167 (90%) adult mosquitoes identified as Ae. aegypti.ConclusionThe epidemiologic, entomologic, and laboratory investigation confirmed a DF outbreak. Mosquito indices were far above safe thresholds, indicating inadequate vector control. We recommended improved vector surveillance and control programs, including best practices in preserving water and disposal of open containers to reduce Aedes mosquito density