702 research outputs found

    Integrated effect of seeding rate, herbicide dosage and application timing on durum wheat (Triticum turgidum l. var durum) yield, yield components and wild oat (avena fatua l.) control in south eastern Ethiopia

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    Knowledge of optimal combinations of crop densities, herbicide dose and time of application could improve the effectiveness and net benefit of commonly used herbicides. A study was conducted at two locations in SARC on-station and farmer’s field, South Eastern Ethiopia for two years from 2007 to 2008. The experimental design was randomized complete block (RCB) design with split-plot arrangement. Durum wheat (Triticum turgidum) seeding rates (recommended, 25% and 50% plus recommended rate) were arranged in the main plot. Four wild oat (Avena fatua) herbicide, Topik, doses (0, 25, 50 and 100 % of the recommended dose) and three timing of applications (14 DA, 32 DAE and 50 DAE) were used as sub-plot treatments. The treatments were compared to determine their effect on durum wheat yield, yield components wild oat densities and control efficacies. Durum wheat seeding rates significantly influenced grain and biomass yield, spike per unit area and kernel weight. Seeding rate of 225 kg ha-1 produced highest grain yield (3810.4 kg ha-1) while 150 kg ha-1 recorded the lowest. Mean wild oat density count before herbicide application timings varied over the two locations averaging 37 and 87 seedlings m-2. Increasing seed rate by 25 and 50% increased wild oat control efficacy by 16.9 and 21.5% respectively. Spraying the herbicide at later growth stages caused greater wild oat seedling density and reduced wheat yield at both locations. The highest efficacy (94.04%) was obtained in the second time of application (30 DAE) of 1 l lit ha-1. The highest reduction in population density was occurred in 100% herbicide rate. There was a general decline in wild oat density in the early application and as the herbicide dose increased, but the effect of seeding rate varied very slightly. In contrast to the wild oat control efficacy the highest grain yield ha-1 was obtained in the first application date (14 DAE). Durum wheat yield losses in the absence of herbicide application were increased by about 16%. Maximum yield (3870.73 kg ha-1) was obtained at 100% of the herbicide dose very closely followed by 50 and 25% of the recommended rate reducing durum wheat yield only by about 1.6 and 2% respectively. Durum wheat seeding rate, herbicide dosage and application timing had statistically no significant interaction effect. Key words: Durum wheat, Wild oat, Herbicide dose, Seeding rate, Application timing

    Determinants of under-five mortality in Gilgel Gibe Field Research Center, Southwest Ethiopia

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    Background: In developing countries like Ethiopia where there is no vital events registration system and laboratory diagnosis is lacking, causes of death in under-five children and its determinants could not be well known. The objective of this study was to investigate causes of death and its determinants in under-five children in Gilgel Gibe Field Research Center. Methods: A case-control study was conducted from December 12 to 27, 2005. Cases of under-five children who died between August 27, 2004 and September 22, 2005 and controls of alive children with the same age (+/-2 months) as cases were identified by a survey as the study population. Data were collected by trained enumerators using structured questionnaire adopted from World Health Organization (WHO). Causes of death were determined using the expert algorithm based on verbal autopsy data. Results: Neonatal and infant mortality rates were respectively 38 and 76.4 per 1000 live births. The two most common causes of death during neonatal period were prematurity (26.4%) and pneumonia (22.6%). Whereas the top causes of death in post-neonatal period were pneumonia (42%), malaria (37%) and acute diarrheal diseases (30%). Maternal education, practice and perception of mothers on the severity of illness and benefits of modern treatment were found to be independent predictor of child survival. Conclusion: Neonatal causes, pneumonia, malaria and diarrheal diseases were the major killers of under-five children in Ethiopia. In this study, practice of mothers and perceived benefits on the modern treatment are identified as the key predictors of child survival which are amenable to future intervention.The Ethiopian Journal of Health Development Vol. 21 (2) 2007: pp. 117-12

    On Exact Superpotentials, Free Energies and Matrix Models

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    We discuss exact results for the full nonperturbative effective superpotentials of four dimensional N=1\mathcal{N}=1 supersymmetric U(N) gauge theories with additional chiral superfield in the adjoint representation and the free energies of the related zero dimensional bosonic matrix models with polynomial potentials in the planar limit using the Dijkgraaf-Vafa matrix model prescription and integrating in and out. The exact effective superpotentials are produced including the leading Veneziano-Yankielowicz term directly from the matrix models. We also discuss how to use integrating in and out as a tool to do random matrix integrals in the large NN limit.Comment: 14 pages; v2: typos corrected; v3: the scheme for computing exact superpotentials including both the Veneziano-Yankielowicz term and all instanton corrections directly using matrix models is emphasized and references added, to appear in JHE

    An ensemble learning framework for anomaly detection in building energy consumption

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    During building operation, a significant amount of energy is wasted due to equipment and human-related faults. To reduce waste, today\u27s smart buildings monitor energy usage with the aim of identifying abnormal consumption behaviour and notifying the building manager to implement appropriate energy-saving procedures. To this end, this research proposes a new pattern-based anomaly classifier, the collective contextual anomaly detection using sliding window (CCAD-SW) framework. The CCAD-SW framework identifies anomalous consumption patterns using overlapping sliding windows. To enhance the anomaly detection capacity of the CCAD-SW, this research also proposes the ensemble anomaly detection (EAD) framework. The EAD is a generic framework that combines several anomaly detection classifiers using majority voting. To ensure diversity of anomaly classifiers, the EAD is implemented by combining pattern-based (e.g., CCAD-SW) and prediction-based anomaly classifiers. The research was evaluated using real-world data provided by Powersmiths, located in Brampton, Ontario, Canada. Results show that the EAD framework improved the sensitivity of the CCAD-SW by 3.6% and reduced false alarm rate by 2.7%

    Predictors of oedema among children hospitalized with severe acute malnutrition in Jimma University Hospital, Ethiopia:a cross sectional study

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    BACKGROUND: Severe acute malnutrition has two main clinical manifestations, i.e., oedematous and non-oedematous. However, factors associated with oedema are not well established. METHODS: Children 0.5-14 years of age with SAM (MUAC < 11.0 cm or weight-for-height < 70 % of median and/or nutritional oedema) admitted to the nutrition unit were included. Information on infections before and during admission was collected together with anthropometry. Predictors of oedema was analysed separately for younger (< 60 months) and older children (≥ 60 months). RESULTS: 351 children were recruited (median age: 36 months (interquartile range 24 to 60); 43.3% females). Oedema was detected in 61.1%. The prevalence of oedema increased with age, peaked at 37–59 months (75%) and declined thereafter. Infection was more common in the younger group (33% vs. 8.9%, p < 0.001) and in this group children with oedema had less infections (25.2% vs. 45.1%, p = 0.001). In the older group the prevalence of infections was not different between oedematous and non-oedematous children (5.5% v. 14.3%, p = 0.17). In the younger group oedema was less common in children with TB (OR = 0.20, 95% CI: 0.06, 0.70) or diarrhea (OR = 0.40, 95% CI: 0.21, 0.73). CONCLUSIONS: The proportion of oedema in SAM peaked at three to five years of age and a considerable proportion was above 5 years. Furthermore, the prevalence of infection seemed to be lower among children with oedema. Further studies are needed to better understand the role of infection-immunity interaction

    Level and intensity of objectively assessed physical activity among pregnant women from urban Ethiopia.

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    BACKGROUND: Women in low-income countries are generally considered to have a high physical workload which is sustained during pregnancy. Although most previous studies have been based on questionnaires a recent meta-analysis of doubly labeled water data has raised questions about the actual amount of physical activity performed. In this study we report objectively assessed levels of physical activity, cardiorespiratory fitness and muscular fitness among pregnant urban Ethiopian women, and their association with demographic characteristics and anthropometric measures. METHODS: Physical activity was measured for seven consecutive days in 304 women using a combined uniaxial accelerometer and heart rate sensor. Activity energy expenditure was determined using a group calibration in a branched equation model framework. Type and duration of activities were reported using a 24-hour physical activity recall and grip strength was assessed using a dynamometer. RESULTS: Median (interquartile-range, IQR) activity energy expenditure was 31.1 (23.7-42.0) kJ/kg/day corresponding to a median (IQR) physical activity level of 1.46 (1.39-1.58). Median (IQR) time in sedentary, light, and moderate-to-vigorous intensity was 1100 (999-1175), 303 (223-374) and 40 (22-69) min/day, respectively. Mean (standard deviation) sleeping heart rate was 73.6 (8.0) beats/min and grip strength was 21.6 (4.5) kg. Activity energy expenditure was 14% higher for every 10 cm(2) difference in arm muscle area and 10% lower for every 10 cm(2) difference in arm fat area and 10-week difference in gestational age. CONCLUSION: The level and intensity of physical activity among pregnant women from urban Ethiopia is low compared to non-pregnant women from other low income countries as well as pregnant European women from high-income countries.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are

    N=1 Supersymmetric SU(2)rSU(2)^r Moose Theories

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    We study the quantum moduli spaces and dynamical superpotentials of four dimensional SU(2)rSU(2)^r linear and ring moose theories with N=1\mathcal{N}=1 supersymmetry and link chiral superfields in the fundamental representation. Nontrivial quantum moduli spaces and dynamical superpotentials are produced. When the moduli space is perturbed by generic tree level superpotentials, the vacuum space becomes discrete. The ring moose is in the Coulomb phase and we find two singular submanifolds with a nontrivial modulus that is a function of all the independent gauge invariants needed to parameterize the quantum moduli space. The massive theory near these singularities confines. The Seiberg-Witten elliptic curve that describes the quantum moduli space of the ring moose is produced.Comment: 26 pages, 4 figures. A few comments and references added. To appear in PR

    An unidentified TeV source in the vicinity of Cygnus OB2

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    Deep observation (∼113 hrs) of the Cygnus region at TeV energies using the HEGRA stereoscopic system of air Čerenkov telescopes has serendipitously revealed a signal positionally inside the core of the OB association Cygnus OB2, at the edge of the 95% error circle of the EGRET source 3EG J2033+4118, and ∼0.5° north of Cyg X-3. The source centre of gravity is RA αJ2000: 20hr32m07s± 9.2stats±2.2syss, Dec δJ2000: +41°30′30″2.0stat±0.4′sys. The source is steady, has a post-trial significance of +4.6σ, indication for extension with radius 5.6′ at the ∼3σ level, and has a differential power-law flux with hard photon index of - 1.9 ± 0.3stat ± 0.3sys. The integral flux above 1 TeV amounts ∼3% that of the Crab. No counterpart for the TeV source at other wavelengths is presently identified, and its extension would disfavour an exclusive pulsar or AGN origin. If associated with Cygnus OB2, this dense concentration of young, massive stars provides an environment conducive to multi-TeV particle acceleration and likely subsequent interaction with a nearby gas cloud. Alternatively, one could envisage γ-ray production via a jet-driven termination shock.F. A. Aharonian, ... G. P. Rowell, ... [et al

    Do Multinational enterprises push up wages of domestic firms in the Italian Manufacturing sector?

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    This paper analyzes the effects of foreign direct investment on wages paid by domestic firms in the Italian manufacturing sector over the period 2002–2007. In particular, the authors investigate the im-pact of multinational enterprises on wages paid by local firms which operate in the same industry, known and horizontal wage spillovers, or have linkages with multinational enterprises in both downstream and upstream industries, known as vertical wage spillovers. By using a large panel dataset, consisting of 551,000 observations, the authors find evidence of wage spillovers only at inter-industry level and, more specifically, for those firms who supply their goods to multinational enterprises, described as backward wage spillovers. Moreover, findings suggest that the wage spillover effect is strongly affected by the technological gap between local and foreign firms: only workers employed in domestic firms with a low-medium technological absorptive capacity seem to benefit from the presence of multinational enterprises in terms of higher wages

    Targeting drought-tolerant maize varieties in southern Africa: a geospatial crop modeling approach using big data

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    Maize is a major staple food crop in southern Africa and stress tolerant improved varieties have the potential to increase productivity, enhance livelihoods and reduce food insecurity. This study uses big data in refining the geospatial targeting of new drought-tolerant (DT) maize varieties in Malawi, Mozambique, Zambia, and Zimbabwe. Results indicate that more than 1.0 million hectares (Mha) of maize in the study countries is exposed to a seasonal drought frequency exceeding 20% while an additional 1.6 Mha experience a drought occurrence of 10–20%. Spatial modeling indicates that new DT varieties could give a yield advantage of 5–40% over the commercial check variety across drought environments while crop management and input costs are kept equal. Results indicate a huge potential for DT maize seed production and marketing in the study countries. The study demonstrates how big data and analytical tools enhance the targeting and uptake of new agricultural technologies for boosting rural livelihoods, agribusiness development and food security in developing countries
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