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

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

Hydrothermal synthesis of perovskite and pyrochlore powders of potassium tantalate

Potassium tantalate powders were hydrothermally synthesized at 100 to 200 °C in 4 to 15 M aqueous KOH solutions. A defect pyrochlore, Kta_(2)O_(5)(OH). nH2O (n ≈ 1.4), was obtained at 4 M KOH, but at 7–12 M KOH, this pyrochlore was gradually replaced by a defect perovskite as the stable phase. At 15 M KOH, there was no intermediate pyrochlore, only a defect perovskite, K_(0.85)Ta_(0.92)O_(2.43)(OH)_(0.57) 0.15H_(2)O. Synthesis at higher KOH concentrations led to greater incorporation of protons in the perovskite structures. The potassium vacancies required for charge compensation of incorporated protons could accommodate water molecules in the perovskite structure

Hydrothermal synthesis of KNbO_3 and NaNbO_3 powders

Orthorhombic KNbO_3 and NaNbO_3 powders were hydrothermally synthesized in KOH and NaOH solutions (6.7–15 M) at 150 and 200 °C. An intermediate hexaniobate species formed first before eventually converting to the perovskite phase. For synthesis in KOH solutions, the stability of the intermediate hexaniobate ion increased with decreasing KOH concentrations and temperatures. This led to significant variations in the induction periods and accounted for the large disparity in the mass of recovered powder for different processing parameters. It is also believed that protons were incorporated in the lattice of the as-synthesized KNbO_3 powders as water molecules and hydroxyl ions

Walking a Tightrope: Unaccompanied migrant young people, transitions and futures

With the collaboration of Praxis Community Projects and Shpresa Programme, a series of photography workshops were conducted with young people from different backgrounds who have gone through similar experiences of migration. Many of these people came to the UK on their own as children, without their family. Their images narrate the difficult and continuous journey they make, and the life changing transitions that this journey entailed. It is a journey without a clear point of departure or arrival - or a clear sense of direction – but which brings multiple transformations and transitions along the way. People have to negotiate completely different cultural, social and political environments and, most importantly, the constraints of an exclusionary asylum system that has profound effects on their everyday lives. These young people often live with the terrifying uncertainty of not knowing what will happen to them or whether they will be returned to the country from which they have fled

Physicochemical, Nutrient, and Heavy Metal Characterization of Wastewater Released from Wachemo University, SNNPR, Ethiopia

Waste management in higher educational institutions is an existing environmental challenge in Ethiopia. Thus, this study aimed to determine the physicochemical, nutrient, and heavy metals concentration of wastewater generated from Wachemo University, SNNPR, Ethiopia. Three wastewater samples were collected and placed in a refrigerator until sample preparation and analysis. Physicochemical parameters, nutrients, and heavy metals were measured using the Standard Methods of the American Public Health Association. The results of the study were ranged as Temperature (19.00–19.02 oC), TDS (89.9–201 mg/L), E.C (179.9–284 µS/cm), DO (1.5–4.5 mg/L), Turbidity (93.2–513.8 NTU), pH (4.82–7.48), TSS (458.4–143 mg/L), TS (339.7–3889.6 mg/L), BOD (44.9–287.1 mg/L), COD (144.9–869.7 mg/L), phosphate (5.2–13.0 mg/L), sulfate (0.02–280.3 mg/L), nitrate (47.9–54.0 mg/L), NH3–N (0.03–7.39 mg/L). The values of most of the physicochemical parameters, nutrients, and heavy metals are within the permissible limit of FAO and EEPA. However, the concentration of Pb was found to be above the maximum permissible limit set by WHO. Similarly, the values of physicochemical parameters such as BOD, COD, TSS, and E.C were above the acceptable range for wastewater discharged limit set by FAO and EEPA. Thus, the result showed that the wastewater released from Wachamo University pose a risk to the surrounding environment and human health unless a proper waste management system is implemented

Profile blunting and flow blockage in a yield stress fluid: A molecular dynamics study

The flow of a simple glass forming system (a 80:20 binary Lennard-Jones mixture) through a planar channel is studied via molecular dynamics simulations. The flow is driven by an external body force similar to gravity. Previous studies show that the model exhibits both a static [Varnik et al. J. Chem. Phys. 120, 2788 (2004)] and a dynamic [F. Varnik and O. Henrich Phys. Rev. B 73, 174209 (2006)] yield stress in the glassy phase. \blue{These observations are corroborated by the present work, where we investigate how the presence of a yield stress may affect the system behavior in a Poiseuille-type flow geometry.} In particular, we observe a blunted velocity profile across the channel: A relatively wide region in the channel center flows with a constant velocity (zero shear rate) followed by a non linear change of the shear rate as the walls are approached. The observed velocity gradients are compared to those obtained from the knowledge of the shear stress across the channel and the flow-curves (stress versus shear rate), the latter being determined in our previous simulations of homogeneous shear flow. Furthermore, using the value of the (dynamic) yield stress known from previous simulations, we estimate the threshold body force for a complete arrest of the flow. Indeed, a blockage is observed as the imposed force falls below this threshold value. Small but finite shear rates are observed at stresses above the dynamic but below the static yield stress. We discuss the possible role of the \blue{stick-slip like motion} for this observation.Comment: 22 pages, 8 figure

The impact of seat height on 1-min sit-to-stand test performance in COPD: a randomised crossover trial

Study question Is there a difference in the number of repetitions in the 1-minute sit-to-stand (1MSTS) test using an individually adapted seat height to 90° knee flexion (1MSTSIND), compared with the commonly used standard chair seat height of 46 cm (1MSTSSTD), in people with COPD? Methods We conducted a single-centre, single-blinded, randomised crossover trial in people with COPD between August 2020 and March 2021 at a specialised rehabilitation clinic in Switzerland. After a learning 1MSTS test, all participants performed two 1MSTS tests in random order on consecutive days. Participants were blinded, as they did not receive detailed information on the testing protocols. Results 49 individuals with COPD (47% female) participated. In a regression model adjusted for sequence period and subject, 1MSTS test performance was lower on 1MSTSIND compared to 1MSTSSTD (−0.78 repetitions, 95% CI −1.47 to −0.11). In a second regression model additionally including the knee angle and an interaction term (1MSTSIND×knee angle), the interaction term was significant: 0.18 (95% CI 0.05 to 0.30). The limits of agreement were between −5.5 and 4 repetitions. Conclusion Although we observed a statistically significant difference between 1MSTSIND and 1MSTSSTD on a population level, the difference is negligible. Further studies may be needed to determine whether individual adaptation of seat height is needed for very tall or short people to ensure a valid assessment of 1MSTS test performance in COPD

Integration of pediatric mental health in general pediatrics in eritrea: improving access and collaboration

Background: Recognition of mental health problems among children continues to be a diagnostic challenge especially in resource poor countries where integration of such services within the primary health care framework has not been fully successfully. Objective: To document the prevailing mental services among children in Eritrea Methods: prospective descriptive study on policies, practices and interventions targeted at improvement of mental health services among children in Eritrea. Results: The Pediatric Residency Programme established at Orotta School Postgraduate School of Medicine developed a curriculum which was sensitive to recognition and management of mental disorders among children. Of a total of 42 children with mental health disorders, one third had anxiety disorders, 30% had pervasive developmental disorders one quarter psychosomatic disorders and 10% had behaviour disorders predominantly attention deficit disorder. Two illustrative cases have been presented to highlight the challenges and the requisite solutions. Conclusion: The establishment of the Pediatric residency with a dedicated curriculum to address mental health services has contributed to the awareness and integration of such services with primary health care in Eritrea