2,563 research outputs found
Spectral properties and reactivity towards azide of Dicrocoelium dendriticum met-hemoglobin
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Contemporary military geosciences in South Africa
No full textCITATION: Smit, H. & Bezuidenhout, J. (eds) 2019. Contemporary military geosciences in South Africa. Stellenbosch: SUN PReSS, doi:10.18820/9781928480112.The original publication is available at https://africansunmedia.store.it.si/zaContemporary Military Geosciences in South Africa presents the reader with chapters celebrating the scope, reach and impact of themes researched by military geoscientists. The first topics under investigation ranges from battlefield archaeology and battlefield tourism to military environmental management and the development of a unique South African spatial decision support system for military integrated environmental management. This is followed by an in-depth look at contemporary maritime factors at play in South Africa. The book is concluded by an analysis of the issues surrounding military mobility software and terrain negotiability, as well as a comprehensive examination of how geographic factors influence the distribution of natural radionuclides in a military area.1 Perspectives on Battlefield Archaeology and Heritage of the Second Anglo-Boer War / J Knight & D Passmor; 2 Battlefield Tourism at Magersfontein – The Case of Heritage Tourism in the Northern Cape, South Africa / CD van der Merwe; 3 Monitoring of the Implementation of Environmental Management in the Defence Force: A Comparative Analysis of Two South African National Defence Force Military Installations / HB Magagula; 4 Spatial Decision Support for Military Integrated Environmental Management in South Africa / JT Marx & JH van der Merwe; 5 Maritime Southern Africa / M Blaine; 6 Terrain Negotiability: Proposing a Geographic Information Systems Model for the South African Army / A Garcia; 7 South African Army Mobility Modelling Software and its Future Challenges / JD Reinecke, P Nkosi & R Ahmed; 8 The Influence of Geographic Factors on the Distribution of Natural Radionuclides / J Bezuidenhout, HAP Smit & AP Geyserhttps://africansunmedia.store.it.si/za/book/contemporary-military-geosciences/523493Publisher's versio
Consideration of Interference Correlation Properties in a JD-CDMA Mobile Radio System with Coherent Receiver Antenna Diversity
No full textIn code division multiple access (CDMA) mobile radio systems, both intersymbol interference and multiple access interference arise which can be combatted by using Joint Detection (JD) techniques, to reduce the degradation in performance resulting from time variance, coherent receiver antenna diversity (CRAD) can be used. The application of JD techniques offers the possibility to exploit the knowledge of noise covariances at the receiver. If only intercell (cochannel) interference is considered, the noise covariances in the uplink receiver of a multiple receiver antenna CDMA mobile radio system depend mainly on the directions of arrival (DOAs) of the interfering signals and the receiver antenna placement. Therefore, if the interferer DOAs are known at the base station, these covariances could be estimated. In this thesis, a realistic model of the uplink of a JD CDMA mobile radio system with CRAD is described in which the above mentioned interference cancelling method is used. Simulation results according to this model are given and evaluated.Applied SciencesElectrical EngineeringTelecommunications and Traffic Control Systems Grou
Dairy farmers’ perceptions toward the implementation of on-farm Johne’s disease prevention and control strategies
No full textmplementation of specific management strategies on dairy farms is currently the most effective way to reduce the prevalence of Johne’s disease (JD), an infectious chronic enteritis of ruminants caused by Mycobacterium avium subspecies paratuberculosis (MAP). However, dairy farmers often fail to implement recommended strategies. The objective of this study was to assess perceptions of farmers participating in a JD prevention and control program toward recommended practices, and explore factors that influence whether or not a farmer adopts risk-reducing measures for MAP transmission. Semi-structured interviews were conducted with 25 dairy farmers enrolled in a voluntary JD control program in Alberta, Canada. Principles of classical grounded theory were used for participant selection, interviewing, and data analysis. Additionally, demographic data and MAP infection status were collected and analyzed using quantitative questionnaires and the JD control program database. Farmers’ perceptions were distinguished according to 2 main categories: first, their belief in the importance of JD, and second, their belief in recommended JD prevention and control strategies. Based on these categories, farmers were classified into 4 groups: proactivists, disillusionists, deniers, and unconcerned. The first 2 groups believed in the importance of JD, and proactivists and unconcerned believed in proposed JD prevention and control measures. Groups that regarded JD as important had better knowledge about best strategies to reduce MAP transmission and had more JD risk assessments conducted on their farm. Although not quantified, it also appeared that these groups had more JD prevention and control practices in place. However, often JD was not perceived as a problem in the herd and generally farmers did not regard JD control as a “hot topic” in communications with their herd veterinarian and other farmers. Recommendations regarding how to communicate with farmers and motivate various groups of farmers according to their specific perceptions were provided to optimize adoption of JD prevention and control measures and thereby increase success of voluntary JD control programs
Positiv Psychology and the Job Demands-Resources Model, the Influence of Justice and Psychological Capital
No full textWerkgevers willen het beste uit hun medewerkers halen blijkens hun toenemende belangstelling voor positieve psychologie. Tegelijkertijd veronachtzamen zij de impact van (on)rechtvaardigheid. Met het job demands-resources (JD-R) model als leidraad werd in een veldexperiment de impact van rechtvaardigheid en psychologisch kapitaal (PsyCap) op stress en bevlogenheid onderzocht. Het 2 x 2 experiment bestond uit een scenariostudie waarin interactionele rechtvaardigheid en werkdruk werden gemanipuleerd en waaraan 88 respondenten deelnamen. Lineaire regressie toonde significante hoofdeffecten van (on)rechtvaardigheid op de energetische en de motivationele route van het JD-R model. PsyCap werkte niet als moderator, maar toonde eveneens hoofdeffecten. Naast beperkingen luidt de conclusie dat rechtvaardigheid en PsyCap een waardevolle bijdrage kunnen leveren aan een gezondere, productievere werkomgeving met het JD-R model als aanknopingspunt
Knowledge gaps that hamper prevention and control of Mycobacterium avium subspecies paratuberculosis infection
No full textIn the last decades, many regional and country‐wide control programmes for Johne's disease (JD ) were developed due to associated economic losses, or because of a possible association with Crohn's disease. These control programmes were often not successful, partly because management protocols were not followed, including the introduction of infected replacement cattle, because tests to identify infected animals were unreliable, and uptake by farmers was not high enough because of a perceived low return on investment. In the absence of a cure or effective commercial vaccines, control of JD is currently primarily based on herd management strategies to avoid infection of cattle and restrict within‐farm and farm‐to‐farm transmission. Although JD control programmes have been implemented in most developed countries, lessons learned from JD prevention and control programmes are underreported. Also, JD control programmes are typically evaluated in a limited number of herds and the duration of the study is less than 5 year, making it difficult to adequately assess the efficacy of control programmes. In this manuscript, we identify the most important gaps in knowledge hampering JD prevention and control programmes, including vaccination and diagnostics. Secondly, we discuss directions that research should take to address those knowledge gaps
Evaluation of an alternative method of herd classification for infection with paratuberculosis in cattle herds in the United States
No full textObjective - To develop a better system for classification of herd infection status for paratuberculosis (Johne's disease JD]) in US cattle herds on the basis of the risk of potential transmission of Mycobacterium avium subsp paratubeculosis. Sample - Simulated data for herd size and within-herd prevalence; sensitivity and specificity for test methods obtained from consensus-based estimates. Procedures - Interrelationships among variables influencing interpretation and classification of herd infection status for JD were evaluated by use of simulated data for various herd sizes, true within-herd prevalences, and sampling and testing methods. The probability of finding ≥1 infected animal in herds was estimated for various testing methods and sample sizes by use of hypergeometric random sampling. Results - 2 main components were required for the new herd JD classification system: the probability of detection of infection determined on the basis of test results from a sample of animals and the maximum detected number of animals with positive test results. Tables were constructed of the estimated probability of detection of infection, and the maximum number of cattle with positive test results or fecal pools with positive culture results with 95% confidence for classification of herd JD infection status were plotted. Herd risk for JD was categorized on the basis of 95% confidence that the true within-herd prevalence was ≤15%, ≤10%, ≤5%, or ≤2%. Conclusions and Clinical Relevance - Analysis of the findings indicated that a scientifically rigorous and transparent herd classification system for JD in cattle is feasible.Source type: Electronic(1
Honderd jaar van formele onderwysopleiding op Wellington : die Onderwyskollege Wellington: 1896-1989: die Onderwyskollege Boland: 1990-1996
No full textDie bestuur van die Oudstudentebond van die Onderwyskollege Wellington (WOK) het op sy
vergadering van 10 Maart 1992 die eerste keer aan die eeufeesjaar 1996 aandag geskenk, en o.a. bes1uit
dat die geskiedenis van die Kollege juis vir die geleentheid geskryf behoort te word. Aanvanldik is
gepoog om 'n nagraadse student te vind om die geskiedenis op te teken, maar toe die pogings Die geslaag
het Die, het die bestuur op 6 Oktober 1993 besluit om die projek selfte ondemeem.
Die aanvanldike gedagte was dat net die WOK-geskiedenis beskryfmoes word, maar omdat die eeufeesjaar
rondom diehonderd jaar van formeleonderwysersopleiding op Wellington onder die Kaaplandse
Departement van Onderwys sedert die stigtiDg van die "Wellington Teachers' Training School" in 1896
gewentel het, het die Kollege se Eeufeeskornitee op sy vergadering van 29 Februarie 1996 versoek dat
die navorsing oor die volle honderd jaarmoes strek en dus ook die Onderwyskollege Boland moes insluit.
In hierdie verband moet daarop gewys word dat onderwysersopleiding reeds voor 1896 op Wellington by
die Huguenot Seminary, die Wellington Public Boys' School en die Blaanwvallei-skool van nmr. MJ.
Stucki plaasgevind het, maar dit was volgens die informele kwekelingstelsel waarnain hoofstukke 1 en 4
van hierdie naVOISing verwys word.
Die leser sal opmerk dat die geskiedslaywing die jare 1896 sowe1as 1996 insluit, en dus in der waarheid
oor 101 jaar strek. Die tiavorsingspaneel het gevoel dat die jaar 1996 so 'n belangrike jaar was in die
bestaan van onderwyskolleges in die land, dat te veel onsekerhede in die lug sou bly hang as die
navorsing slegs honderdjaar sou dele.
Die paneel het uiteindelikbestaan uit drr. J.J. Joubert, E. Smit en mnr. J.D. Giliomee. Ander persone
wat ook by sekere opleeswerk en waardevolle hulp betrokke was, was mej. S.M Zietsman en nmr. A.F.
van Niekerk. Daarbenewens het 'n he1e aanta1 dosente, ouddosente en ander persone inligtingverskaf hulle
name word aan die einde van die toepasIike hoo:fstukke vermeld.
Die grootste probleem waarvoor die paneel te staan gekom het, was dat feitlik at die leers by die Kollege
tot die laat sestigajare Die opgespoor kon word Die. Die enigste gevolgtrekking waartoe die paneel kon
kom, was dat hierdie leers moontlik met die voltooiing van die nuwe gebouekompleks rond en bont
verskaif en uiteindelik deur iemand onwetend vernietig is. Met die oog op 'n laaste kontrole het die
paneel teen Julie 1996 twee proefkopiee van die navorsing bekikbaar gestel soda! vera! oudstudente en
-dosentedaardeur kon blaai omverdere inligting ofverbeteringe aan die hand te doen. Hierdie proefkopice
was tot by die reiinie van 20-22 September 1996 ter insae beskikbaar, waarna die finale afronding
gedoenis,
Die navorsers kan vanseJfsprekend Die aanspraak op volledigheid maak Die omdat die geskiedenis van
enige opleidingsinrigting oor die loop van 'n honderdjaar die omvang van verskeie bundels sou beslaan.
Die benamingl: wat gebruik word, stem gewoonlik ooreen met die tydperk waarin dit gebmik is. So bv.
is gepraat van die Wellington Teachers' Training School, die Opleidingskool Wellington, die Opleidingskonege
Wellington, die Onderwyserskollege Wellington, die Onderwyskollege Wellington en die Onderwyskollege
Boland.
Die paneel is besonder baie dankverskoJdig aan personeellede van enkele instansies vir hulle hulpvaardigheid
en baie vriendelike bystand: die Kaapse Argiefbewaarplek van die Staatsargief, die Argief van
die Kaaplandse Onderwysdeparteent, die MJ.L 01ivier-biblioteek van die Onderwyskollege Boland,
die WellingtonMuseumen die Suid-Aftikaanse Onderwysersunie te Kaapstad.
Dr. J.N.S. du Plessis bet die manuslcrip taalknndig' nagesien en die tikwerk is deur dr. Etienne Smit
behartig. Besondere dank is ook aan oudstudent Van As Jordaan van Varia Urtgewers verskuldig wat
deursy finansiele ondersteuning en onderhandelinge die buitebladvir ODS moontlik gemaak het
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