Browsing Natural and Agricultural Sciences by Title

Browsing Natural and Agricultural Sciences by Title

Sort by: Order: Results:

  • Declining citation accuracy in polar research 
    McIntyre, T.; Haussmann, N.S. (Natalie) (Cambridge University Press, 2021)
    Accurate citation practices are important to ensure a robust knowledge base and overall trustworthy academic enterprise. The prevalence of poor citation practices has been assessed in multiple fields, resulting in estimates ...
  • Declining tobacco production : analysing key drivers of change 
    Du Preez, Cal (University of Pretoria, 2016)
    The size of the South African tobacco industry has been shrinking over the last 20 years. Tobacco production has decreased by 54% between 1990 and 2014. Along with the decline in the area of tobacco planted, the number of ...
  • Decomposing the variance in southern elephant seal weaning mass : partitioning environmental signals and maternal effects 
    Oosthuizen, Wessel Christiaan; Bester, Marthan Nieuwoudt; Altwegg, Res; McIntyre, Trevor; De Bruyn, P.J. Nico (Ecological Society of America, 2015-08)
    Predator populations are likely to respond to bottom-up processes, but there remains limited understanding of how wide-ranging marine predators respond to environmentally driven temporal variation in food availability.Widespread ...
  • Deconstructing compassionate conservation 
    Hayward, Matt W.; Callen, Alex; Allen, Benjamin L.; Ballard, Guy; Broekhuis, Femke; Bugir, Cassandra K.; Clarke, Rohan H.; Clulow, John; Clulow, Simon; Daltry, Jennifer C.; Davies-Mostert, Harriet T.; Fleming, Peter J.S.; Griffin, Andrea S.; Howell, Lachlan G.; Kerley, Graham I.H.; Klop-Toker, Kaya L.; Legge, Sarah; Major, Tom; Meyer, Ninon; Montgomery, Robert A.; Moseby, Katherine; Parker, Daniel M.; Periquet, Stephanie; Read, John; Scanlon, Robert J.; Seeto, Rebecca G.Y.; Shuttleworth, Craig M.; Somers, Michael J.; Tamessar, Cottrell T.; Tuft, Katherine; Upton, Rose M.O.; Valenzuela-Molina, Marcia; Wayne, Adrian; Witt, Ryan R.; Wuster, Wolfgang (Wiley, 2019-08)
    Compassionate conservation focuses on 4 tenets: first, do no harm; individuals matter; inclusivity of individual animals; and peaceful coexistence between humans and animals. Recently, compassionate conservation has been ...
  • Deconstructing Jaco : genetic heritage of an Afrikaner 
    Greeff, Jaco M. (Jacobus Maree) (Blackwell, 2007-09)
    It is often assumed that Afrikaners stem from a small number of Dutch immigrants. As a result they should be genetically homogeneous, show founder effects and be rather inbred. By disentangling my own South African pedigree, ...
  • Deconvolution models for determining the real surface composition of InP (1 0 0) after bombardment with 5 keV Ar ions at different angles 
    Odendaal, R.Q. (Quintin); Malherbe, Johan B. (Elsevier, 2019-12)
    Low energy ion bombardment can induce compositional changes in the surfaces of compound materials. A fundamental problem is to determine which of the two main mechanisms caused the compositional change, viz. preferential ...
  • Deel 1 : Ontmoet die skaapvleisverbruiker 
    Hurter, Tineil; Bester, Marina (Agri Connect (Pty) Ltd, 2016-01)
    Die feit dat skaapvleis alreeds 'n duurder produk is (in vergelyking met ander proteïen kommoditeite) is 'n realiteit en daarom is Skaapvleis SA se verbruikersopvoeding hoofsaaklik gemik op die hoër LSM-verbruiker in ...
  • Deel 2 : Ontmoet die skaapvleisverbruiker : hoe bereik mens die verbruikers? 
    Hurter, Tineil; Bester, Marina (Agri Connect (Pty) Ltd, 2016-06)
    In die vorige uitgawe (Vol.7, No.2: "Ontmoet die skaapvleisverbruiker" - Deel 1, p.92) is 'n prentjie geskets van hoe die tipiese Suid-Afrikaanse skaapvleisverbruiker lyk. Daar is tot die slotsom gekom dat Skaapvleis SA ...
  • Deep digital gene expression profiling during early and late tension wood induction in Eucalyptus trees 
    Silberbauer, Janine Francina (University of Pretoria, 2011)
    Genetic engineering of superior wood properties and exploiting natural genetic variation found within commercially important trees, such as Eucalyptus spp., promise to increase cellulose biomass production. It is therefore ...
  • Deep divers in even deeper seas : habitat use of male southern elephant seals from Marion Island 
    McIntyre, Trevor; Bornemann, Horst; Plotz, Joachim; Tosh, Cheryl A.; Bester, Marthan Nieuwoudt (Cambridge University Press, 2012)
    We describe the habitat use of 22 male southern elephant seals (Mirounga leonina) satellite tagged at Marion Island between 2004 and 2008. While a few areas of increased utilization appeared to be associated with areas ...
  • Deep learning diagnostics of gray leaf spot in maize under mixed disease field conditions 
    Craze, Hamish A.; Pillay, Nelishia; Joubert, Fourie; Berger, David Kenneth (MDPI, 2022-07-26)
    Maize yields worldwide are limited by foliar diseases that could be fungal, oomycete, bacterial, or viral in origin. Correct disease identification is critical for farmers to apply the correct control measures, such as ...
  • Deep level transient spectroscopy (DLTS) study of defects introduced in antimony doped Ge by 2 MeV proton irradiation 
    Nyamhere, Cloud; Das, A.G.M.; Auret, Francois Danie; Chawanda, Albert; Pineda-Vargas, C.A.; Venter, Andre (Elsevier, 2011-08)
    Please read the abstract in the article.
  • A deep MeerKAT search for neutral hydrogen in, and lensed by, dense environments 
    Ranchod, Shilpa (University of Pretoria, 2020-12)
    Neutral hydrogen (HI) is a key ingredient in galaxy formation and an excellent tracer of galaxy evolution and the environmental drivers thereof. HI volume density varies significantly with environment, where denser ...
  • Defect charge states in Si doped hexagonal boron-nitride monolayer 
    Mapasha, Refilwe Edwin; Molepo, Mahlanga P.; Andrew, Richard Charles; Chetty, Nithaya (IOP Publishing, 2016-02)
    We perform ab initio density functional theory calculations to investigate the energetics, electronic and magnetic properties of isolated stoichiometric and non-stoichiometric substitutional Si complexes in a hexagonal ...
  • Defect levels induced by double substitution of B and N in 4H-SiC 
    Igumbor, Emmanuel; Danga, Helga Tariro; Omotoso, Ezekiel; Meyer, Walter Ernst (Elsevier, 2019-03)
    Please read abstract in the article.
  • Defect production in strained p-type Si1-xGex by Er implantation 
    Mamor, M.; Pipeleers, B.; Auret, Francois Danie; Vantomme, M. (American Institute of Physics, 2011-01)
    Strained p-Si1−xGex (x = 5.3%, 10.2%, and 15.4%) was irradiated at room temperature with 160 keV 166Er2+ ions to a fluence of 1×1010 or 3×1013 Er/cm2. The defects induced by ion implantation were investigated experimentally ...
  • Defect states of complexes involving a vacancy on the boron site in boronitrene 
    Ngwenya, T. Bongani; Ukpong, Aniekan M.; Chetty, Nithaya (American Physical Society, 2011-12)
    First principles calculations have been performed to investigate the ground state properties of freestanding monolayer hexagonal boronitrene (h-BN). We have considered monolayers that contain native point defects and ...
  • Defects in swift heavy ion irradiated n-4H-SiC 
    Tunhuma, Shandirai Malven; Diale, M. (Mmantsae Moche); Nel, Jacqueline Margot; Madito, M.J. (Moshawe); Hlatshwayo, Thulani Thokozani; Auret, Francois Danie (Elsevier, 2019-12)
    Please read abstract in the article.
  • Defects induced by solid state reactions at the tungsten-silicon carbide interface 
    Tunhuma, Shandirai Malven; Diale, M. (Mmantsae Moche); Legodi, Matshisa Johannes; Nel, Jacqueline Margot; Thabethe, Thabsile Theodora; Auret, Francois Danie (American Institute of Physics Inc., 2018-01-18)
    Defects introduced by the solid state reactions between tungsten and silicon carbide have been studied using deep level transient spectroscopy (DLTS) and Laplace DLTS. W/4H-SiC Schottky barrier diodes were isochronally ...
  • Defence transcriptome assembly and pathogenesis related gene family analysis in Pinus tecunumanii (low elevation) 
    Visser, Erik A.; Wegrzyn, Jill L.; Myburg, Alexander Andrew; Naidoo, Sanushka (BioMed Central, 2018-08-23)
    BACKGROUND : Fusarium circinatum is a pressing threat to the cultivation of many economically important pine tree species. Efforts to develop effective disease management strategies can be aided by investigating the ...