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Maize–lablab intercropping is promising in supporting the sustainable intensification of smallholder cropping systems under high climate risk in southern Africa
Edith Rapholo, Jude J. O. Odhiambo, William C. D. Nelson, Reimund P. Rötter, Kingsley Ayisi, Marian Koch, Munir P. Hoffmann
Published online by Cambridge University Press: 01 July 2019, pp. 1-14
Identifying options for the sustainable intensification of cropping systems in southern Africa under prevailing high climate risk is needed. With this in mind, we tested an intercropping system that combined the staple crop maize with lablab, a local but underutilised legume. Grain and biomass productivity was determined for four variants (i) sole maize (sole-maize), (ii) sole lablab (sole-lablab), (iii) maize/lablab with both crops sown simultaneously (intercropped-SP) and (iv) maize/lablab with lablab sown 28 days after the maize crop (intercropped-DP). Soil water and weather data were monitored and evaluated. The trial was conducted for two seasons (2015/2016 and 2016/2017) at two sites in the Limpopo Province, South Africa: Univen (847 mm rainfall, 29.2 °C maximum and 18.9 °C minimum temperature average for the cropping season over the years 2008–2017) and Syferkuil (491 mm rainfall, with 27.0 °C maximum and 14.8 °C minimum temperature). Analysis revealed three key results: The treatment with intercropped-SP had significantly lower maize yields (2320 kg ha−1) compared with maize in intercropped-DP (2865 kg ha−1) or sole-maize (2623 kg ha−1). As expected, maize yields in the El Niño affected in season 2015/2016 were on average 1688 kg ha−1 lower than in 2016/2017. Maize yields were significantly lower (957 kg ha−1) at Univen, the warmer site with higher rainfall, than at Syferkuil. In 2015/2016, maximum temperature at Univen exceeded 40 °C around anthesis. Furthermore, soil water was close to the estimated permanent wilting point (PWP) for most of the cropping season, which indicates possible water limitations. In Syferkuil, the soil water was maintained well above PWP. Lablab yields were low, around 500 ha−1, but stable as they were not affected by treatment across season and site. Overall, the study demonstrated that intercropped-DP appears to use available soil water more efficiently than sole maize. Intercropped-DP could therefore be considered as an option for sustainable intensification under high climate risk and resource-limited conditions for smallholders in southern Africa.
Unsolved Major Problems of Interacting Binaries — A Panel Discussion
P. P. Eggleton, R. H. Koch, Y. Kondo, D. M. Popper, J. I. Smak, F. B. Wood
Journal: Symposium - International Astronomical Union / Volume 151 / 1992
SPectral Observation of the Soft X-Ray Background and of the North Polar Spur with Solid State Spectrometers
R. Rocchia, M. Arnaud, C. Blondel, C. Cheron, J. C. Christy, L. Koch, R. Rothenflug, H. W. Schnopper, J. P. Delvaille
In this paper, we present preliminary results of soft X-ray diffuse background observations. We observed two particular regions of the sky in the 0.3–1.5 keV range. The detection system consisted of three independent, 1 cm diameter, cooled solid state detectors. Nearly overlapping fields of view subtended a solid angle of approximately 1/4 sr. Except for the field of view, the whole set was similar to that described in Schnopper et al. (1982) (hereafter referred to as paper 1). This system was flown on board a three-axis stalibized rocket. The flight took place at White Sands Missile Range on 1981 May 4 at 0755 UT.
Earliest Eocene Cooling? Comparison of Isotopic and Paleobotanical Estimates of Temperature During the Paleocene- Eocene Transition
P. L. Koch, H. Bao, S. L. Wing
Journal: The Paleontological Society Special Publications / Volume 8 / 1996
Ion angular distribution simulation of the Highly Efficient Multistage Plasma Thruster
Solved and Unsolved problems in Plasma Physics
J. Duras, D. Kahnfeld, G. Bandelow, S. Kemnitz, K. Lüskow, P. Matthias, N. Koch, R. Schneider
Journal: Journal of Plasma Physics / Volume 83 / Issue 1 / February 2017
Published online by Cambridge University Press: 22 February 2017, 595830107
Ion angular current and energy distributions are important parameters for ion thrusters, which are typically measured at a few tens of centimetres to a few metres distance from the thruster exit. However, fully kinetic particle-in-cell (PIC) simulations are not able to simulate such domain sizes due to high computational costs. Therefore, a parallelisation strategy of the code is presented to reduce computational time. The calculated ion beam angular distributions in the plume region are quite sensitive to boundary conditions of the potential, possible additional source contributions (e.g. from secondary electron emission at vessel walls) and charge exchange collisions. Within this work a model for secondary electrons emitted from the vessel wall is included. In order to account for limits of the model due to its limited domain size, a correction of the simulated angular ion energy distribution by the potential boundary is presented to represent the conditions at the location of the experimental measurement in $1~\text{m}$ distance. In addition, a post-processing procedure is suggested to include charge exchange collisions in the plume region not covered by the original PIC simulation domain for the simulation of ion angular distributions measured at $1~\text{m}$ distance.
Cortical thickness and surface area correlates with cognitive dysfunction among first-episode psychosis patients
L. Haring, A. Müürsepp, R. Mõttus, P. Ilves, K. Koch, K. Uppin, J. Tarnovskaja, E. Maron, A. Zharkovsky, E. Vasar, V. Vasar
Journal: Psychological Medicine / Volume 46 / Issue 10 / July 2016
In studies using magnetic resonance imaging (MRI), some have reported specific brain structure–function relationships among first-episode psychosis (FEP) patients, but findings are inconsistent. We aimed to localize the brain regions where cortical thickness (CTh) and surface area (cortical area; CA) relate to neurocognition, by performing an MRI on participants and measuring their neurocognitive performance using the Cambridge Neuropsychological Test Automated Battery (CANTAB), in order to investigate any significant differences between FEP patients and control subjects (CS).
Exploration of potential correlations between specific cognitive functions and brain structure was performed using CANTAB computer-based neurocognitive testing and a vertex-by-vertex whole-brain MRI analysis of 63 FEP patients and 30 CS.
Significant correlations were found between cortical parameters in the frontal, temporal, cingular and occipital brain regions and performance in set-shifting, working memory manipulation, strategy usage and sustained attention tests. These correlations were significantly dissimilar between FEP patients and CS.
Significant correlations between CTh and CA with neurocognitive performance were localized in brain areas known to be involved in cognition. The results also suggested a disrupted structure–function relationship in FEP patients compared with CS.
42. Close Binary Stars
A. H. Batten, J. Smak, K. D. Abhyankar, J. Andersen, A. M. Cherepashchuk, M. Kitamura, R. H. Koch, Y. Kondo, K-C. Leung, M. Rodono, G. Shavlv, E. P. J. van den Heuvel, B. Warner
Journal: Transactions of the International Astronomical Union / Volume 19 / Issue 1 / 1985
Research on close binary systems has continued at a high level during the past triennium, although the rate of growth is noticeably slower – probably reflecting the cutbacks in funds to which many of us are subject. There have also been changes of emphasis within the field, which are commented on in the pages that follow. These reflect both changing opportunities for observation and the natural development of the subject. In many areas, the time is ripe for a more critical look at ideas that previously seemed adequate.
42. Close Binary Stars (Etoiles Binaires Serrees)
A. Yamasaki, T. J. Herczeg, G. Hill, M. Rodonò, R. W. Hilditch, R. H. Koch, J. C. Raymond, G. E. McCluskey, R. S. Polidan, B. Geldzahler, A. Gimenez, A. P. Boss, E. F. Guinan, P. Szkody, S. Starrfield, R. F. Webbink
Status of the Perth Observatory Automated Supernova Search Program
A. J. Williams, D. G. Blair, R. Burman, M. Evans, R. Martin, P. V. Birch, M. P. Candy, A. Verveer, R. Koch, M. J. Lynch, X. Dai, M. G. Zadnik, D. Foster
Journal: Publications of the Astronomical Society of Australia / Volume 9 / Issue 1 / 1991
The Perth Astronomy Research Group (PARG), consisting of members from Curtin University of Technology, Perth Observatory and the University of Western Australia, is in the process of developing an automated supernova search system, using the 61-cm Lowell-Perth reflector, a CCD camera and an 80386-based computer for image analysis. Computer control of the telescope and dome, a liquid-nitrogen-cooled CCD camera, and modified VISTA image analysis software will be completed in late 1990, allowing initial semi-automatic searching of external galaxies, together with CCD photometry of flare stars and newly discovered supernovae. Full-scale automation will be introduced subsequently, in collaboration with the Berkeley group. This paper describes the project, and reports on its current status.
Observation of Ionization of Laser Excited Atoms by Synchrotron Radiation
J.M. Bizau, F. Wuilleumier, P. Gerard, P. Dhez, B. Carré, G. Spiess, D.L. Ederer, J.L. Picqué, J.L. LeGouet, J.C. Keller, P. Koch
Journal: International Astronomical Union Colloquium / Volume 86 / 1984
We have begun a program to measure oscillator strengths of autoionizing resonances that result from a transition in the VUV between a laser excited initial state and a final state in which a core electron is promoted. These measurements demonstrate a new technique to combine synchrotron radiation, laser pumping, and photoelectron spectroscopy.
Measurements of the energy positions of autoionizing resonances have been honed to a fine art over the past 50 years. Total cross section measurements and the parameters that describe autoionizing resonances have been determined. Most of these studies have been made from the dipole allowed ground state. Recently autoionizing resonances have been observed from excited initial states and from ion initial states. We have heard several talks, at this meeting which described some of this type of research. In the measurements to be described in this paper, laser radiation is combined with synchrotron radiation, as shown schematicaly in Figure 1, to study the photoionization from excited initial states to continuum final states or to autoionizing final states. Continuum radiation from the Aneau de Collisions d'Orsay (ACO), which is installed at the Universite de Paris-Sud, in Orsay France, is monochromatized by a toroidal grating monochromator (TGM) and is focused by a toroidal output mirror on to a weakly collimated sodium beam emanating from a furnace mounted on the axis of a cylinderical mirror analyzer (CMA). This electron spectrometer is used to study the kinetic energy distribution of the ejected photoelectrons produced by the interaction of the photon beam with the focused synchrotron radiation.
Evidence for the Roche Lobe Overflow in VV Cephei
E. F. Guinan, G. P. McCook, R. H. Koch, R. J. Pfeiffer
Journal: Highlights of Astronomy / Volume 7 / 1986
The VV Cep close binary system (O8V + M2 lab; P = 20 3 yrs.) is described from published spectral, radial velocity, photometric, and astrometric results. A long-term photometric monitoring program shows intrinsic variability in a red bandpass. Variability exists on several time scales and the longest of these is attributed to tidal distortion of the cool supergiant by the equally massive hot companion. A theoretical "distortion" light curve, when faced against the observations, indicated the radius of the supergiant to be significantly smaller than the accepted value of ~1600R⊙. This conclusion is examined in the context of a pulse of polarized red light occurring near the time of periastron and interpreted as Roche Lobe overflow of the supergiant envelope. It is shown that the photometric and polarimetrie results may be made accordant, not by appeal to a very large level of scattered red light, but rather by invoking the loss of constraint originally imposed by the Roche Lobe geometry.
On the expected distribution of species' ranges
Carl F. Koch, John P. Morgan
Journal: Paleobiology / Volume 14 / Issue 2 / Spring 1988
Print publication: Spring 1988
A method is provided to calculate the expected distribution of species' ranges for use as a basis of comparison for paleontological interpretation of species' range charts. If the method is used for such studies, the possibility of suggesting an environmental or biological cause for observed patterns, when in fact no such cause exists, will be diminished. The method is applied to a large, well-studied fossil data set to illustrate some possible species' range patterns which result only from sample size inequities. As examples, stepwise extinction and species richness patterns are predicted for situations where, in reality, none exist.
By Vanessa Agnew, Gregory Barz, Michael Beckerman, Stephen Blum, Philip V. Bohlman, Salwa El-Shawan Castelo-Branco, Martin Clayton, Nicholas Cook, Timothy J. Cooley, Ruth F. Davis, Beverley Diamond, Aaron A. Fox, Keith Howard, Bernardo Illari, Travis A. Jackson, Jaime Jones, Margaret Kartomi, Sebastian Klotz, Lars-Christian Koch, Peter Manuel, Wayne Marshall, Kaley Mason, Richard Middleton, Bruno Nettl, Regula Burckhardt Qureshi, Ronald Radano, Suzel Ana Reily, Timothy Rommen, Kay Kaufman Shelemay, W. Anthony Sheppard, Jonathan P. J. Stock, Martin Stokes, Timothy D. Taylor, Bonnie C. Wade, Bennett Zon
Edited by Philip V. Bohlman, University of Chicago
Book: The Cambridge History of World Music
Print publication: 12 December 2013, pp xv-xxiii
Quantitative Reconstruction and Analysis of HRTEM Complex Exit Waves using Inline Holography
C. Ophus, J. Ciston, P. Ercius, C. Koch
Extended abstract of a paper presented at Microscopy and Microanalysis 2013 in Indianapolis, Indiana, USA, August 4 – August 8, 2013.
Ovine fetal renal development impacted by multiple fetuses and uterine space restriction
K. M. Meyer-Gesch, M. Y. Sun, J. M. Koch, J. Ramadoss, S. E. Blohowiak, R. R. Magness, P. J. Kling
Journal: Journal of Developmental Origins of Health and Disease / Volume 4 / Issue 5 / October 2013
Intrauterine growth restriction (IUGR) from uteroplacental dysfunction causes impaired nephrogenesis and ultimately hypertension, but it is unknown whether IUGR caused by insufficient space for placental development seen in uterine anomalies and/or multifetal gestation exerts the same effects. Fetal renal development and metabolism were studied in an ovine space-restriction model by combining unilateral horn surgical ligation and/or multifetal gestation. Reduced placental attachment sites and placental weight per fetus defined space-restricted (USR) v. control nonrestricted (NSR) fetuses. Space-restricted fetuses exhibited evidence for decreased plasma volume, with higher hematocrit and plasma albumin at gestational day (GD) 120, followed by lower blood pO2, and higher osmolarity and creatinine at GD130, P < 0.05 for all. By combining treatments, fetal kidney weight relative to fetal weight was inversely related to both fetal weight and plasma creatinine levels, P < 0.05 for both. At GD130, space-restricted fetal kidney weights, cortical depths and glomerular generations were decreased, P < 0.05 for all. Space-restricted kidneys underwent an adaptive response by prolonging active nephrogenesis and increasing maculae densa number, P < 0.05 for both. The major renal adaptations in space-restricted IUGR fetuses included immaturity in both development and endocrine function, with evidence for impaired renal excretory function.
Break-up testing of waste-form materials
M. P. Metcalfe, W. Koch, G. Turner
Journal: Mineralogical Magazine / Volume 76 / Issue 8 / December 2012
The Nuclear Decommissioning Authority (NDA) is developing a safety case for the long-term management of higher activity wastes. This includes safety assessments of transport to and operations at the repository. One of the main faults and hazards to be considered is waste package response to impact accidents.
The criteria of impact performance for waste packages are based upon activity release of particulates generated from the break up of the waste form during impact. The NDA approach to impact performance is based upon waste package response from finite element modelling in combination with break-up tests.
Previous break up research commissioned by the NDA has concentrated on commercial graphite and glass samples. These extended studies, undertaken by the National Nuclear Laboratory in collaboration with the Department of Aerosol Technology of the Fraunhofer Institute of Toxicology and Experimental Medicine, provide break-up data specific to nuclear facilities and waste materials. These include archived unirrradiated graphite used to construct Magnox reactor cores and reflectors, simulant high level waste glass, selected grout formulations and selected metal-in-grout formulations.
Flow of power-law fluids in fixed beds of cylinders or spheres
John P. Singh, Sourav Padhy, Eric S. G. Shaqfeh, Donald L. Koch
Journal: Journal of Fluid Mechanics / Volume 713 / 25 December 2012
An ensemble average of the equations of motion for a Newtonian fluid over particle configurations in a dilute fixed bed of spheres or cylinders yields Brinkman's equations of motion, where the disturbance velocity produced by a test particle is influenced by the Newtonian fluid stress and a body force representing the linear drag on the surrounding particles. We consider a similar analysis for a power-law fluid where the stress $\boldsymbol{\tau} $ is related to the rate of strain $ \mathbisf{e} $ by $\boldsymbol{\tau} = 2m \mathop{ \vert \mathbisf{e} \vert }\nolimits ^{n\ensuremath{-} 1} \mathbisf{e} $ , where $m$ and $n$ are constants. In this case, the ensemble-averaged momentum equation includes a body force resulting from the nonlinear drag exerted on the surrounding particles, a power-law stress associated with the disturbance velocity of the test particle, and a stress term that is linear with respect to the test particle's disturbance velocity. The latter term results from the interaction of the test particle's velocity disturbance with the random straining motions produced by the neighbouring particles and is important only in shear-thickening fluids where the velocity disturbances of the particles are long-ranged. The solutions to these equations using scaling analyses for dilute beds and numerical simulations using the finite element method are presented. We show that the drag force acting on a particle in a fixed bed can be written as a function of a particle-concentration-dependent length scale at which the fluid velocity disturbance produced by a particle is modified by hydrodynamic interactions with its neighbours. This is also true of the drag on a particle in a periodic array where the length scale is the lattice spacing. The effects of particle interactions on the drag in dilute arrays (periodic or random) of cylinders and spheres in shear-thickening fluids is dramatic, where it arrests the algebraic growth of the disturbance velocity with radial position when $n\geq 1$ for cylinders and $n\geq 2$ for spheres. For concentrated random arrays of particles, we adopt an effective medium theory in which the drag force per unit volume in the medium surrounding a test particle is assumed to be proportional to the local volume fraction of the neighbouring particles, which is derived from the hard-particle packing. The predictions of the averaged equations of motion are validated by comparison with simulations of randomly distributed hydrodynamically interacting cylinders.
Guillotine versus dissection tonsillectomy: randomised, controlled trial
S J Frampton, M J A Ward, V S Sunkaraneni, H Ismail-Koch, Z A Sheppard, R J Salib, P K Jain
Journal: The Journal of Laryngology & Otology / Volume 126 / Issue 11 / November 2012
Published online by Cambridge University Press: 11 September 2012, pp. 1142-1149
This trial aimed to compare the guillotine technique of tonsillectomy with 'cold steel' dissection, the current 'gold standard'.
A single centre, randomised, controlled trial.
One hundred children aged 3 to 11 years who were listed for bilateral tonsillectomy were recruited. Patients had one tonsil removed by each technique, and were blinded to the side. The operative time, intra-operative blood loss, haemostasis requirement and post-operative pain scores were recorded and compared.
Operative time and intra-operative blood loss were both significantly less for the guillotine technique (p < 0.001) and there was a significantly reduced haemostasis requirement (p < 0.001). Pain was also less on the guillotine side (p < 0.001). There were no tonsillar remnants or palatal trauma for either technique. There was no significant difference between techniques in the frequency of secondary haemorrhage.
This study provides level Ib evidence that guillotine tonsillectomy in children with mobile tonsils is an effective and time-efficient procedure which produces less intra-operative blood loss and post-operative pain than cold steel dissection.
Magnetic field morphologies at mpc scale
Ya-Wen Tang, Patrick M. Koch, Paul T. P. Ho, Stephane Guilloteau, Anne Dutrey
Journal: Proceedings of the International Astronomical Union / Volume 10 / Issue H16 / August 2012
Published online by Cambridge University Press: 05 March 2015, p. 392
We report our new results of the magnetic field (B) morphologies toward W51 North, traced with the linear polarization of the dust continuum at wavelengths of 870 μm. The B morphologies are resolved with an angular resolution of typically 1" using the Submillimeter Array (SMA). Dense structures with a number density 105 to 107 cm−3 are traced. In comparison, the B morphologies of sources at different evolutionary stages, from the collapsing core in W51 e2 (Tang et al. 2009a) and part of Orion BN/KL (Tang et al. 2010) to the ultra-compact HII region G5.89-0.39 (Tang et al. 2009b) clearly exhibit different morphologies, likely suggesting different roles of the B fields at different stages.
Proteomics reveals that a high-fat diet induces rapid changes in hypothalamic proteins related to neuronal damage and inflammation
L. M. Williams, F. Nicol, C. Grant, A. C. Morris, M. Reid, P. Nicol, C. Koch, N. Hoggard, A. Tups, F. M. Campbell
Journal: Proceedings of the Nutrition Society / Volume 70 / Issue OCE6 / 2011
Published online by Cambridge University Press: 27 January 2012, E370