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Litterfall and Nutrient Release in Mature Pinus radiata in the South-western Cape
Item type: Journal Article • Journal: South African Forestry Journal • Authors: D.B. Versfeld --- Division of Forest Science and Technology, CSIR, Jonkershoek F.R.C., D. G.M. Donald --- Faculty of Forestry,Fast-growing plantations of conifers have replaced areas of mediterranean shrubland in the south-western Cape. This study arises from the need to quantify the impacts of major changes in primary productivity, litterfall, and nutrient cycling in terms of the site utilisation... -
Effect of seeding date on the performance of grasses and broadleaf species evaluated for cover crop management in two wine grape regions of South Africa
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: J.C. Fourie --- , Republic of South Africa P. J.E. Louw --- , Republic of South Africa G.A. Agenbag --- Department of Agronomy, Republic of South AfricaA selection of species suitable for cover crop management in the different wine grape regions is required to enable more producers to apply this environment friendly practice in a sustainable manner as part of an integrated production strategy. The effect... -
Carbon and nitrogen mineralisation and inactivation of the Cry1Ab protein in Bt maize (MON810) residues during composting
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: CK Daudu --- Department of Agronomy, South Africa P Muchaonyerwa --- School of Agricultural, Earth and Environmental Sciences, South Africa PNS Mnkeni --- Department of Agronomy, South AfricaA study was carried out to determine the effects of composting Bt maize residues on carbon (C) and nitrogen (N) contents and activity of the Cry1Ab protein in the compost. Residues (leaf plus stem) of mature Bt maize (DKC 7815B)... -
Chickpea residue properties controlling decomposition dynamics and nitrogen availability in some tropical acid soils
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: Benjamin O Danga --- Department of Agricultural Resource Management, Kenya Aviva Hadas --- Department of Soil Chemistry and Plant Nutrition, Israel Isaiah IC Wakindiki --- Department of Agronomy, South Africa Josephine P Ouma --- Department of Crops, Horticulture and Soils, Kenya Asher Bar-Tal --- Department of Soil Chemistry and Plant Nutrition, IsraelChickpea (Cicer arietinum) grown in a rotation can contribute significant nitrogen (N) if its decomposition and nutrient-release dynamics are known and synchronised with the maximum demand by the succeeding crop. The aims of the study were to investigate the decomposition... -
DECOMPOSITION IN ESTUARINE ECOSYSTEMS
Item type: Journal Article • Journal: Journal of the Limnological Society of Southern Africa • Authors: MH Schleyer --- , South AfricaThe varied sources of estuarine plant detritus and the processes and organisms involved in its decomposition are discussed in this review. In the case of emergent and peripheral vegetation, microbial decomposition commences in the phylloplane, with fairly rapid leaching of... -
ECOLOGICAL PROBLEMS IN HARTBEESPOORT DAM
Item type: Journal Article • Journal: Journal of the Limnological Society of Southern Africa • Authors: AndrewC. Jarvis --- National Institute for Water Research,In Hartbeespoort Dam ecological problems arise primarily as a consequence of the reservoir's hypertrophic condition. The development of anaerobic conditions, high primary productivity and blue-green algal dominance have many detrimental influences on ecosystem structure and function. With high rates of... -
THE PROCESSING OF UNCONFINED, NATURALLY ENTRAINED LEAVES IN TWO LOW-ORDER SOUTHERN AFRICAN MOUNTAIN STREAMS
Item type: Journal Article • Journal: Southern African Journal of Aquatic Sciences • Authors: S.J. Lamberth --- Zoology Department, South Africa B.A. Stewart --- , South Africa B.R. Davies --- Zoology Department, South AfricaBreakdown of unconfined and confined leaves of the riparian tree Brabejum stellatifolium L. was investigated in two low order mountain streams (Window Stream and Langrivier) in the southwestern Cape, South Africa. At both sites, 5000 unconfined leaves were released in... -
Fully Trend Preserving Operators
Item type: Journal Article • Journal: Quaestiones Mathematicae • Authors: C.H. RohwerThe concept of fully trend preserving (ftp) operators on sequences was introduced to prove variation preservation on the outputs of LULU-separators. It turns out that this property is central in further analysis of compositions of LULU-smoothers, and other smoothers. Several... -
WELL-BOUNDED OPERATORS ON NON-REFLEXIVE BANACH SPACES II
Item type: Journal Article • Journal: Quaestiones Mathematicae • Authors: Qingping Cheng --- Institute of Mathematics, Hebrew University of Jerusalem, Givat-Ram, Jerusalem, Israel, Ian Doust --- School of Mathematics, University of New South Wales, Sydney, NSW, Australia,In this paper we examine the relationship between the various subclasses of well-bounded operators. Although some of these subclasses have been shown to coincide on certain families of Banach spaces, we show here that apart from these previously known cases,... -
Litter Fall and Decomposition in Stands of Mature Pinus radiata
Item type: Journal Article • Journal: South African Forestry Journal • Authors: D.B. Versfeld --- Department of Water Affairs, Forestry and Environmental Conservation,Rates of litter fall in mature stands of Pinus radiata D. Don have been monitored at the Jonkershoek Forestry Research Station since 1976. Decomposition trials were laid out in June 1977. Litter fall has been collected on six sites in... -
Doob's decomposition of set-valued submartingales via ordered near vector spaces
Item type: Journal Article • Journal: Quaestiones Mathematicae • Authors: CoenraadC.A. Labuschagne AndrewL. PinchuckWe use ideas from measure-free martingale theory and Rådström's completion of a near vector space to derive a Doob decomposition of submartingales in ordered near vector spaces. As a special cases thereof, we obtain the Doob decomposition of set-valued submartingales,... -
Decompositions of zonoids
Item type: Journal Article • Journal: Quaestiones Mathematicae • Authors: R. Anantharaman --- ,A zonoid is the range of a non atomic vector measure μ into ℝn. We examine, by example, a result of Bolker: “Every zonoid K that is not a line segment is decomposable: i.e., is the sum of two sets,... -
The influence of the NYSE of the risk of JSE stocks
Item type: Journal Article • Journal: De Ratione • Authors: D.J. Bradfield --- University of Cape Town,In this article the influence of the NYSE on the risk of securities on the JSE is investigated. A technique for obtainine. Risk coefficients which capture the sensitivity of securities on the JSE to movements on the NYSE is demonstrated... -
Decomposition of cattle dung on grazed signalgrass (Brachiaria decumbens Stapf) pastures in monoculture or intercropped with tree legumes
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: Hugo NB Lima --- Animal Science, Brazil Jose C Dubeux Jr --- North Florida Research and Education Center, USA Mercia VF dos Santos --- Animal Science, Brazil Alexandre CL de Mello --- Animal Science, Brazil Mario A Lira --- Animal Science, Brazil Marcio V Cunha --- Animal Science, BrazilLivestock excreta is one of the major nutrient sources in natural grasslands. Understanding how livestock diet and season affects the decomposition dynamics is critical to nutrient cycling models. We hypothesised that livestock diet and season of the year affect dung... -
Diversification and the realised volatility of equity portfolios
Item type: Journal Article • Journal: Investment Analysts Journal • Authors: Hannes du Plessis --- Department of Finance and Tax, South Africa Paul van Rensburg --- Department of Finance and Tax, South AfricaIn Markowitz’s (1952) portfolio theory, a reduction in volatility for a given level of expected return is implied as being equivalent to an increase in diversification. The recent development of risk-based portfolio construction methods, which emphasise diversification separately from volatility... -
Measuring maize production efficiency in the eastern Ethiopia: Stochastic frontier approach
Item type: Journal Article • Journal: African Journal of Science, Technology, Innovation and Development • Authors: Musa Hasen Ahmed --- Department of Agricultural Economics, Ethiopia Aemro Tazeze --- Department of Agricultural Economics, Ethiopia Alem Mezgebo --- Department of Agricultural Economics, Ethiopia Eden Andualem --- Department of Agricultural Economics, EthiopiaThis study evaluated the technical, economic and allocative efficiency of maize production in eastern Ethiopia using cross-sectional data collected from 480 maize plots. The stochastic production function, fitted using the Cobb–Douglas production function, indicated that the amount of seed, land... -
Forest gap size can efficiently promote litter decomposition and nutrient release in south-western China
Item type: Journal Article • Journal: Southern Forests: a Journal of Forest Science • Authors: Xun Li --- Key Laboratory of Ecological Forestry Engineering, China Danju Zhang --- Key Laboratory of Ecological Forestry Engineering, China Yan Zhang --- Key Laboratory of Ecological Forestry Engineering, China Jian Zhang --- Key Laboratory of Ecological Forestry Engineering, China Simeng Song --- Key Laboratory of Ecological Forestry Engineering, China Yang Zhou --- Key Laboratory of Ecological Forestry Engineering, ChinaForest gaps are important in forest dynamics and management; however, the gap size that is most conducive to the decomposition of litter and promotion of nutrient cycling in forests remains poorly understood. The mass loss and nutrient release from Pinus... -
In situ leaf litter production, decomposition and nutrient release of dry Afromontane trees
Item type: Journal Article • Journal: East African Agricultural and Forestry Journal • Authors: Emiru Birhane --- Department of Land Resources Management and Environmental Protection, Ethiopia Tekleab Desalegn --- Department of Land Resources Management and Environmental Protection, Ethiopia Fassil Kebede --- Department of Land Resources Management and Environmental Protection, Ethiopia Kidane Giday --- Department of Land Resources Management and Environmental Protection, Ethiopia Hadgu Hishe --- Department of Land Resources Management and Environmental Protection, Ethiopia Kiros Meles Hadgu --- World Agroforestry Centre (ICRAF), EthiopiaThe litter fall production, decomposition and subsequent nutrient release of Carrisa edulis, Juniperus procera, Maytenus obscura and Olea europaea was monitored in the dry Afromontane forest of Northern Ethiopia by collecting abscised leaves using litter trap with a 192 litter... -
Impact of the 2008 wage review on the public-private sector wage-gap in Cameroon
Item type: Journal Article • Journal: African Journal of Science, Technology, Innovation and Development • Authors: Ebenezer Lemven Wirba --- , Cameroon Fiennasah Annif’ Akem --- , Cameroon Francis Menjo Baye --- , CameroonThis paper examines the impact of the 2008 wage review on the public-private sector wage-gap in Cameroon. Specifically, the paper evaluates the determinants of participating in the labour market and choosing formal sector employment; assesses the correlates of wages in... -
Temporal effects of biocontrol processes on nutrient dynamics in a shallow lake: Case study of Lake Xini, Okavango Delta in Botswana
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: CN Kurugundla --- , Botswana JC Buru --- , AustraliaLittle is known about the effects of weeds on nutrient concentration changes in aquatic environments. We examined alterations to nutrient dynamics from the biocontrol process of Salvinia molesta by the weevil Cyrtobagous salviniae in the Lake Xini of Okavango, Botswana... -
An analysis of stock market prices by using extended Kalman filter: The US and China cases
Item type: Journal Article • Journal: Investment Analysts Journal • Authors: Özge Sezgin Alp --- Başkent University, Turkey Levent Özbek --- Ankara University, Turkey Bilge Canbaloglu --- Ankara Yıldırım Beyazıt University, TurkeyThis study decomposes the trend-cycle components of the stock market indices of the United States and China in a time series framework over the period of 1980–2021, and 1992–2021 years, respectively. Using the extended Kalman filter (EKF) method, the changing... -
The effect of crop rotation and tillage practice on residue decomposition and wheat performance in the Western Cape, South Africa
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: Johannes Stephanus Theron --- Stellenbosch University, South Africa Gerhardus Johannes van Coller --- , South Africa Lindy Joy Rose --- Stellenbosch University, South Africa Johan Labuschagne --- Stellenbosch University, South Africa Pieter Andreas Swanepoel --- Stellenbosch University, South AfricaConservation agriculture relies on residue retention, crop rotation and reduced tillage. Crop rotation determines residue type, while tillage affects residue load and distribution. Although crop residue retention is often beneficial, residues can create challenges, including obstruction of planters during establishment... -
On localization of the Menger property
Item type: Journal Article • Journal: Quaestiones Mathematicae • Authors: Nur Alam --- University of Gour Banga, India Debraj Chandra --- University of Gour Banga, IndiaIn this paper we introduce and study the local version of the Menger property, namely locally Menger property (or, locally Menger space). We explore some preservation like properties in this space. We also discuss certain situations where this local property... -
A Hahn-Jordan decomposition and Riesz-Frechet representation theorem in Riesz spaces
Item type: Journal Article • Journal: Quaestiones Mathematicae • Authors: Anke Kalauch --- Institut für Analysis, FR Mathematik, TU Dresden, Germany Wenchi Kuo --- University of the Witwatersrand, South Africa Bruce A. Watson --- University of the Witwatersrand, South AfricaWe give a Hahn-Jordan decomposition in Riesz spaces which generalizes that of [B.A. Watson, An Andô-Douglas type theorem in Riesz spaces with a conditional expectation, Positivity, 13 (2009), 543–558] and a Riesz-Frechet representation theorem for the T-strong dual, where T... -
The influence of Connochaetes taurinus carcass decomposition on soil nutrient composition in grasslands
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: EA Kullander --- University of South Africa, South Africa MS Deutschländer --- University of South Africa, South Africa VM Ngole-Jeme --- University of South Africa, South Africa HI Melville --- University of South Africa, South AfricaDecomposing carcasses leach nutrients into soils, forming dense, nutrient-rich islands. The effect of liquid influx on ecological dynamics from decomposing blue wildebeest (Connochaetes taurinus) carcasses on soil nutrient content at various stages of decomposition in a grassland ecosystem was investigated... -
Forecasting oil futures markets using machine learning and seasonal trend decomposition
Item type: Journal Article • Journal: Investment Analysts Journal • Authors: Ahhyun Kim --- Sungkyunkwan University, Korea Doojin Ryu --- Sungkyunkwan University, Korea Alexander Webb --- University of Wollongong, AustraliaCan machine learning improve prediction for seasonal commodity prices? We explore the effectiveness of a combined method that integrates seasonal trend decomposition using LOESS (STL) with machine learning (ML), referred to as STL-ML. We apply Extreme Gradient Boosting and Random... -
The Common Hermitian Solutions of the matrix equations
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New properties of some classes of Saphar type operators
Item type: Journal Article • Journal: Quaestiones Mathematicae • Authors: Ayoub Ghorbel --- University of Sfax, Tunisia Snežana Č. Živković-Zlatanović --- University of Niš, SerbiaThis paper explores additional properties of some classes of Saphar type operators, namely left Drazin invertible, essentially left Drazin invertible, right Drazin invertible, and essentially right Drazin invertible operators on Banach spaces, building upon the groundwork laid in [8] and... -
Characterizations of the semi-harmonious and harmonious quasi-projection pairs on Hilbert C ∗-modules
Item type: Journal Article • Journal: Quaestiones Mathematicae • Authors: Xiaoyi Tian --- Shanghai Normal University, P.R. China Qingxiang Xu --- Shanghai Normal University, P.R. China Chunhong Fu --- Health School Attached to Shanghai University of Medicine & Health Sciences, P.R. ChinaFor each adjointable idempotent Q on a Hilbert C ∗ -module , a specific projection m(Q) called the matched projection of Q was introduced recently due to the characterization of the minimum value among all the distances from projections to Q...