Reduction in livestock losses following placement of livestock guarding dogs and the impact of herd species and dog sex

Livestock guarding dogs have been placed on South African farms by the not-for-profit organisation, Cheetah Outreach Trust, since 2005, and have been proven to be an efficient form of non-lethal predator control against jackal, caracal, leopards, cheetahs and other predators found in South Africa. However, the impact that herd species (sheep, goat, cattle or mixed) or the sex of the dog may have on the observed reduction in livestock losses following placement of a livestock guarding dogs has not been investigated. To address this, the reduction in livestock losses following placement of an Anatolian livestock guarding dogs was measured in two South African provinces over a nine year period and data simultaneously collected on herd type and dog sex. Dogs comprised of 78 males and 49 females. Farms consisted of 68 sheep, 37 goats, 23 cattle, and two exotic game farms. Effectiveness was measured as the difference between farmer-reported livestock losses before and after the placement of a dog and was calculated as percentage change in stock loss after introduction of a livestock guarding dog according herd species and dog sex. This study determined the impact of herd type or dog sex on the difference between livestock loss before versus after livestock guarding dog s placement. This study indicates that the use of this breed of livestock guarding dog is an effective means of reducing perceived livestock losses due to predation, regardless of dog sex, and may be used with equal effectiveness with a range of herd species

Navorsing in Suid-Afrika in verband met die vraagstuk van druiping onder eerstejaarstudente op universiteit*

Wanaanpassing in die lewe, meer bepaald op universiteit, veral ten opsigte van druiping onder eerstejaarstudente by wie die verskynsel homselfhoofsaaklik voordoen, is ’n lastige, wyeen wêreldvraagstuk met baie ekonomiese, sedelike, opvoedkundige en anderimplikasies wat nie alleen die universiteit raak nie maar ook ander instansies soos die Provinsiale Onderwysdepartemente, die Staat, die ouerhuis, ens

Die taalvraagstuk tydens unie

By geleentheid van die Nasionale Konvensie (1909), wat die Unie voorafgegaan het, was die taalvraagstuk feitlik die spil waarom alles gedraai het, en daar is allerweë besef dat dit nutteloos sou wees om met die besprekings voort te gaan tensy daar op dié gebied eers ’n bevredigende oplossing gevind word

Die Eerste Verhoudinge Tussen Boer en Brit.

Mens hoor deesdae, veral van Engelse kant, weer heelwat omtrent die „gevoel,” „rassehaat” e.s.m. wat daar dan tussen Afrikaans- en Engelssprekendes sou bestaan. Nou wil ek sommer dadelik sê dat dit een van dié oordrewe en gevaarlike algemeenhede is wat maklik is om te beweer maar wat gewoonlik op onkunde en/of kwaadwilligheid berusen meestal ook nie bewys kan word nie, iets wat dikwels sommer uit die lug gegryp is en hoofsaaklik op papier bestaan—in Engels sou ek met’n woordspeling wou sê: „On paper, more specifically, in the Englishpapers.

Histamine and Tyramine Content of South African Wine

The histamine content of 184 wines and tyramine content of 156 wines, produced in South Africa was measured. The histamine and tyramine content of the wine was found to be similar to those of wines produced in other countries. The average histamine content of South African red wines that had undergone malo-lactic fermentation was more than double that of red wines that had not undergone malo-lactic fermentation. All the red wines containing relatively large amounts of histamine had pH's above 3, 7. Six selected strains of malo-lactic bacteria were tested for their ability to form histamine and tyramine in white and red wine. No histamine or tyramine was formed

Quantifying Long-Term Urban Grassland Dynamics: Biotic Homogenization and Extinction Debts

Sustainable urban nature conservation calls for a rethinking of conventional approaches. Traditionally, conservationists have not incorporated the history of the landscape in management strategies. This study shows that extant vegetation patterns are correlated to past landscapes indicating potential extinction debts. We calculated urban landscape measures for seven time periods (1938–2019) and correlated it to three vegetation sampling events (1995, 2012, 2019) using GLM models. We also tested whether urban vegetation was homogenizing. Our results indicated that urban vegetation in our study area is not currently homogenizing but that indigenous forb species richness is declining significantly. Furthermore, long-term studies are essential as the time lags identified for different vegetation sampling periods changed as well as the drivers best predicting these changes. Understanding these dynamics are critical to ensuring sustainable conservation of urban vegetation for future citizens

Qualitatively speaking: Deciding how much data and analysis is enough

As I traverse my (post) doctoral journey, reworking my thesis into publications, I was immersed again in a debate around the utility of the concept of data saturation. I believe this debate to be emblematic of the process of unlearning and relearning that unfolded during my doctoral journey, coming from a biomedical sciences background into qualitative educational research

Developing an ionospheric map for South Africa

The development of a map of the ionosphere over South Africa is presented in this paper. The International Reference Ionosphere (IRI) model, South African Bottomside Ionospheric Model (SABIM), and measurements from ionosondes in the South African Ionosonde Network, were combined within their own limitations to develop an accurate representation of the South African ionosphere. The map is essentially in the form of a computer program that shows spatial and temporal representations of the South African ionosphere for a given set of geophysical parameters. A validation of the map is attempted using a comparison of Total Electron Content (TEC) values derived from the map, from the IRI model, and from Global Positioning System (GPS) measurements. It is foreseen that the final South African ionospheric map will be implemented as a Space Weather product of the African Space Weather Regional Warning Centre

Application of neural networks to South African GPS TEC modelling

The propagation of radio signals in the Earth’s atmosphere is dominantly affected by the ionosphere due to its dispersive nature. Global Positioning System (GPS) data provides relevant information that leads to the derivation of total electron content (TEC) which can be considered as the ionosphere’s measure of ionisation. This paper presents part of a feasibility study for the development of a Neural Network (NN) based model for the prediction of South African GPS derived TEC. The South African GPS receiver network is operated and maintained by the Chief Directorate Surveys and Mapping (CDSM) in Cape Town, South Africa. Vertical total electron content (VTEC) was calculated for four GPS receiver stations using the Adjusted Spherical Harmonic (ASHA) model. Factors that influence TEC were then identified and used to derive input parameters for the NN. The well established factors used are seasonal variation, diurnal variation, solar activity and magnetic activity. Comparison of diurnal predicted TEC values from both the NN model and the International Reference Ionosphere (IRI-2001) with GPS TEC revealed that the IRI provides more accurate predictions than the NN model during the spring equinoxes. However, on average the NN model predicts GPS TEC more accurately than the IRI model over the GPS locations considered within South Africa