The aryl hydrocarbon receptor (AhR) binds synthetic and chemoprotective phytochemicals, and research in this laboratory has developed selective AhR modulators (SAhRMs) for treatment of breast cancer. Activation of the AhR through agonists such as TCDD inhibits hormone activation of several E2-responsive genes in breast cancer cell lines. In this study, inhibition of E2-induced proliferation and gene expression by TCDD has been investigated in the uterus of wildtype, ERKO and AhRKO mice. Cyclin D1, DNA polymerase ?, and VEGF mRNA levels are induced by E2 through ER? in the uterus as determined by in situ hybridization studies. TCDD down-regulated E2-induced cyclin D1 and DNA polymerase ? expression, but not E2-induced VEGF expression, in wild-type mice, but not AhRKO mice, confirming the role of the AhR. Furthermore, protein synthesis was not necessary for induction of cyclin D1 or DNA polymerase ?gene expression by E2 or inhibition of these responses by TCDD. Therefore, AhR-ER? crosstalk directly regulates the expression of genes involved in cell proliferation in vivo. AhR agonists induce down-regulation of ErbB family receptors in multiple tissues/organs suggesting possible inhibitory interactions with chemotherapeutic potential. Recently, it has been reported that the SAhRM 1,1??,2,2??-tetramethyldiindolylmethane inhibited DMBA-induced mammary tumor growth in rats and also inhibited MAPK and PI3-K pathways in human breast cancer cells. BT-474 and MDA-MB-453 cell lines are ErbB2-overexpressing breast cancer cells that express functional AhR and exhibit constitutive activation of MAPK and PI3-K pathways. Therefore, 1,1??,2,2??-tetramethyldiindolylmethane-induced inhibition of ErbB2 signaling was investigated in these cells lines and in the MMTV-c-neu mouse mammary tumor model, which overexpresses ErbB2 in the mammary gland. The growth of ErbB2 overexpressing cell lines and mammary tumors was inhibited by 1,1??,2,2??-tetramethyldiindolylmethane; however, modulation of MAPK or PI3-K pathways and cell cycle proteins nor induction of apoptosis by 1,1',2,2'-tetramethyldiindolylmethane was observed in the ErbB2overexpressing cell lines. Current studies are investigating mitochondrial effects of 1,1??,2,2??-tetramethyldiindolylmethane in the ErbB2-overexpressing cell lines, as well as continuing studies on gene expression profiles in the mammary glands of MMTV-c-neu mice to better understand and identify critical genes that are responsible for ErbB2-mediated transformation and growth of cancer cells/tumors.

<p>Background: Performance measurement as a management control tool has received considerable academic attention. As the number of inter-organisational relationships, such as customer-supplier relationships, increases, there is a new scope for performance measurement as a management control tool. In order for a company to assess the effectiveness of its supplier relationships it has to define, measure and evaluate variables that are critical for the success of the relationship. The role of management control, and thereby of performance measurement, has increasingly been discussed in theory. However, empirical research in this area is still somewhat limited. </p><p>Purpose: The purpose of the thesis is to analyse how performance measurement in inter-organisational relationships should be designed in order to be effective. </p><p>Results: Theory which is applicable on performance measurement as a control tool in general also appears to be applicable on performance measurement as a control tool in inter-organisational relationships. Exactly which requirements performance measurement should meet, in order to be effective, is difficult to establish since they often imply a trade-off between different factors. In order to be effective, performance measurement partly needs to be adjusted to the situation, which adds yet a dimension to, and difficulty of, performance measurement in inter-organisational relationships.</p>

No description available.

The environmental impacts of genetically modified (GM) crop plants such as Bt (Bacillus thuringiensis) maize have not yet been fully assessed in South Africa. Bt maize designed to express Bt endotoxin for control of Busseola fusca (Fuller) (Lepidoptera: Noctuidae) and Chilo partellus (Swinhoe) (Lepidoptera: Crambidae) is planted on approximately 1.103 million hectares in South Africa. The monitoring of GM crops after release is important in order to assess and evaluate possible environmental effects. No risk assessment for Bt maize was done in South Africa before its release in 1998 and no targeted post-release monitoring of possible resistance development or impact on non-target species have been done. Awareness has risen in South Africa through research highlighting the possible effects GM crops may have. The aim of this study was to determine, through feeding experiments, the effects of Bt maize on selected non-target Lepidoptera, Coleoptera and Diptera species that occur in maize agro-ecosystems in South Africa. Results provide information for use in future risk assessment studies on Bt maize and indicate which species could possibly be of importance in post-release monitoring of Bt maize. Priority insect species were identified and laboratory- and semifield experiments were conducted to evaluate the effect of Bt maize on these species. In the light of the reportedly lower toxicity of Bt maize to certain noctuid borers, the effect of Bt maize was evaluated on Sesamia calamistis (Hampson), Agrotis segetum (Denis & Schiffermüller), and Helicoverpa armigera (Hubner). Feeding studies were also conducted to determine the effect of Bt maize on non-target Coleoptera, i.e. Heteronychus arator Fabricius (Coleoptera: Scarabaeidae) and Somaticus angulatus (Fahraeus) (Coleoptera: Tenebrionidae). The effect of indirect exposure of the stem borer parasitoid Sturmiopsis parasitica (Curran) (Diptera: Tachinidae) to Bt toxin was evaluated to determine if there is any effect when it parasitizes Bt-resistant B. fusca larvae that have fed on Bt maize. Results from the study conducted with S. calamistis indicated that Bt maize of both events (Bt11 and MON810) were highly toxic to S. calamistis. The behavioural characteristic of S. calamistis to feed behind leaf sheaths and to enter stems directly did not result in escape of exposure to the toxin. Larval feeding on leaf sheaths therefore resulted in the ingestion of sufficient toxin to kill larvae before they entered maize stems. Results showed that the effect of Cry1Ab toxin on the biology of A. segetum larvae and moths were largely insignificant. Whorl leaves were observed to be an unsuitable food source for H. armigera larvae and larval growth was poor. No larvae survived to the pupal stage on any of the Bt maize treatments. When feeding on maize ears H. armigera larval mass increased on non-Bt maize whereas no increase occurred on Bt maize. The feeding study conducted with Coleoptera showed that the effect of Bt maize on H. arator and S. angulatus was insignificant and no differences were observed in any of the parameters measured for the two species. Although not always significant, the percentage parasitism of Bt-consuming host larvae by S. parasitica was always higher compared to host larvae that fed on non-Bt maize. It could be that Bt toxin affects B. fusca fitness to such an extent that the immune systems of host larvae were less effective. The different parameters tested for S. parasitica indicated only one case where fly maggots originating from diapause host larvae feeding on non-Bt maize had a greater mass compared to host larvae that fed on Bt maize. The same applied to S. parasitica pupal length. For other parameters tested there were no significant differences. Sesamia calamistis is stenophagous and occurs in mixed populations with other borer species. It was therefore concluded that the ecological impact of local extinctions of S. calamistis caused by Bt maize is not expected to be great. Bt maize will most likely not have any significant effect on the control of A. segetum under field conditions. The feeding study conducted with H. armigera quantified the effects of Bt maize on this species and provided important information on the potential of Bt maize as protection against this polyphagous pest. However, the likelihood of H. armigera becoming an important secondary pest is high. It can be concluded that the Cry1Ab toxin targeting lepidopteran pests will not have adverse effects on H. arator or S. angulatus. Although some adverse effects were observed on S. parasitica mass and pupal length it is most likely that this will not contribute to adverse effects in the field, but that there rather be synergism between Bt maize and S. parasitica. An ecological approach was followed in which the potential effects of exposure of priority species to Bt toxin in maize was investigated. A series of selection matrixes were developed in which each of the above mentioned species was ranked for its maximum potential exposure to Bt toxin by assessing it occurrence, abundance, presence and linkage in the maize ecosystem. Through the use of these selection matrixes, knowledge gaps were identified for future research and to guide the design of ecologically realistic experiments. This study contributes to knowledge regarding the possible effects of Bt maize on the most economically important non-target pests in South Africa. There is, however, a need to evaluate other non-target species in feeding studies, as well as in field studies. From this study it can be concluded that some species can be eliminated from further testing since Bt maize had no adverse effect while more research have to be conducted on other species. / Thesis (Ph.D. (Environmental Science)--North-West University, Potchefstroom Campus, 2010.

Resistance development and possible non–target effects have been of concern since the first deployment of genetically modified crops with insecticidal properties. It is especially at the third trophic level and with important predators such as lacewings (Chrysoperla spp.) (Neuroptera: Chrysopidae) where negative effects of Cry 1Ab protein could have adverse effects in agro–ecosystems. Monitoring of the effect of genetically modified Bt maize on non–target organisms is required by law in South–Africa. Neuroptera are excellent indicators of environmental and habitat transformation, and also include key species for signifying areas and faunas that require priority protection. Monitoring techniques, especially for insect eggs, are often labour intensive and time consuming. A study was conducted to determine the preferred oviposition site of Chrysoperla spp. on maize plants to facilitate time–effective searching for eggs of these beneficial insects. Furthermore we determined if the presence of aphids on plants influenced Chrysoperla spp. oviposition preference. Another study was conducted to evaluate the effect of indirect exposure of C. pudica to Cry 1Ab protein, through healthy Bt–maize feeding prey, on its biology. Daily flight activity patterns and the height at which chrysopid adults fly above the crop canopy were also determined, as well as the movement of adult Chrysoperla spp. between maize fields and adjacent headlands. A clear spatial oviposition pattern was observed on maize plants and oviposition was not random as reported in earlier studies. This data facilitates rapid monitoring of the presence of eggs in maize cropping systems and is also of use in general pest management. Choicetest data showed that females responded positively to host plants that were infested with aphids. Feeding studies in which C. pudica larvae were indirectly exposed to Bt–toxin at the 3rd trophic level, showed a limited effect of Bt–toxin on only a few of the parameters that were evaluated. The pupal period and percentage adult emergence of larvae exposed to an unusually high amount of Bt–toxin was significantly shorter and lower respectively than that of the control group. The overall result of this study, in which the possible effect of food quality (prey) was excluded, showed that Cry 1Ab protein had an adverse affect only on certain fitness components during the life cycle of C. pudica. However, since this study represented a worst–case scenario where diverse prey was not available to C. pudica, negligible effects is expected under field conditions where prey is more diverse. It was determined that chrysopids was most active between 16:00 – 23:00 and that they fly largely between 0.5 m – 2.5 m above ground level. An attempt was also made to quantify migration between different vegetations types. This part was terminated because of bad weather conditions at several occasions when the experiment was attempted. Chrysopids were never present in grassland vegetation, but an adjacent lucerne field maintained a large population. As the maize crop developed chrysopid population numbers increased inside the field, presumably originating from the lucerne field. / Thesis (M.Sc (Environmental Science))--North-West University, Potchefstroom Campus, 2011.

The environmental impacts of genetically modified (GM) crop plants such as Bt (Bacillus thuringiensis) maize have not yet been fully assessed in South Africa. Bt maize designed to express Bt endotoxin for control of Busseola fusca (Fuller) (Lepidoptera: Noctuidae) and Chilo partellus (Swinhoe) (Lepidoptera: Crambidae) is planted on approximately 1.103 million hectares in South Africa. The monitoring of GM crops after release is important in order to assess and evaluate possible environmental effects. No risk assessment for Bt maize was done in South Africa before its release in 1998 and no targeted post-release monitoring of possible resistance development or impact on non-target species have been done. Awareness has risen in South Africa through research highlighting the possible effects GM crops may have. The aim of this study was to determine, through feeding experiments, the effects of Bt maize on selected non-target Lepidoptera, Coleoptera and Diptera species that occur in maize agro-ecosystems in South Africa. Results provide information for use in future risk assessment studies on Bt maize and indicate which species could possibly be of importance in post-release monitoring of Bt maize. Priority insect species were identified and laboratory- and semifield experiments were conducted to evaluate the effect of Bt maize on these species. In the light of the reportedly lower toxicity of Bt maize to certain noctuid borers, the effect of Bt maize was evaluated on Sesamia calamistis (Hampson), Agrotis segetum (Denis & Schiffermüller), and Helicoverpa armigera (Hubner). Feeding studies were also conducted to determine the effect of Bt maize on non-target Coleoptera, i.e. Heteronychus arator Fabricius (Coleoptera: Scarabaeidae) and Somaticus angulatus (Fahraeus) (Coleoptera: Tenebrionidae). The effect of indirect exposure of the stem borer parasitoid Sturmiopsis parasitica (Curran) (Diptera: Tachinidae) to Bt toxin was evaluated to determine if there is any effect when it parasitizes Bt-resistant B. fusca larvae that have fed on Bt maize. Results from the study conducted with S. calamistis indicated that Bt maize of both events (Bt11 and MON810) were highly toxic to S. calamistis. The behavioural characteristic of S. calamistis to feed behind leaf sheaths and to enter stems directly did not result in escape of exposure to the toxin. Larval feeding on leaf sheaths therefore resulted in the ingestion of sufficient toxin to kill larvae before they entered maize stems. Results showed that the effect of Cry1Ab toxin on the biology of A. segetum larvae and moths were largely insignificant. Whorl leaves were observed to be an unsuitable food source for H. armigera larvae and larval growth was poor. No larvae survived to the pupal stage on any of the Bt maize treatments. When feeding on maize ears H. armigera larval mass increased on non-Bt maize whereas no increase occurred on Bt maize. The feeding study conducted with Coleoptera showed that the effect of Bt maize on H. arator and S. angulatus was insignificant and no differences were observed in any of the parameters measured for the two species. Although not always significant, the percentage parasitism of Bt-consuming host larvae by S. parasitica was always higher compared to host larvae that fed on non-Bt maize. It could be that Bt toxin affects B. fusca fitness to such an extent that the immune systems of host larvae were less effective. The different parameters tested for S. parasitica indicated only one case where fly maggots originating from diapause host larvae feeding on non-Bt maize had a greater mass compared to host larvae that fed on Bt maize. The same applied to S. parasitica pupal length. For other parameters tested there were no significant differences. Sesamia calamistis is stenophagous and occurs in mixed populations with other borer species. It was therefore concluded that the ecological impact of local extinctions of S. calamistis caused by Bt maize is not expected to be great. Bt maize will most likely not have any significant effect on the control of A. segetum under field conditions. The feeding study conducted with H. armigera quantified the effects of Bt maize on this species and provided important information on the potential of Bt maize as protection against this polyphagous pest. However, the likelihood of H. armigera becoming an important secondary pest is high. It can be concluded that the Cry1Ab toxin targeting lepidopteran pests will not have adverse effects on H. arator or S. angulatus. Although some adverse effects were observed on S. parasitica mass and pupal length it is most likely that this will not contribute to adverse effects in the field, but that there rather be synergism between Bt maize and S. parasitica. An ecological approach was followed in which the potential effects of exposure of priority species to Bt toxin in maize was investigated. A series of selection matrixes were developed in which each of the above mentioned species was ranked for its maximum potential exposure to Bt toxin by assessing it occurrence, abundance, presence and linkage in the maize ecosystem. Through the use of these selection matrixes, knowledge gaps were identified for future research and to guide the design of ecologically realistic experiments. This study contributes to knowledge regarding the possible effects of Bt maize on the most economically important non-target pests in South Africa. There is, however, a need to evaluate other non-target species in feeding studies, as well as in field studies. From this study it can be concluded that some species can be eliminated from further testing since Bt maize had no adverse effect while more research have to be conducted on other species. / Thesis (Ph.D. (Environmental Science)--North-West University, Potchefstroom Campus, 2010.

Resistance development and possible non–target effects have been of concern since the first deployment of genetically modified crops with insecticidal properties. It is especially at the third trophic level and with important predators such as lacewings (Chrysoperla spp.) (Neuroptera: Chrysopidae) where negative effects of Cry 1Ab protein could have adverse effects in agro–ecosystems. Monitoring of the effect of genetically modified Bt maize on non–target organisms is required by law in South–Africa. Neuroptera are excellent indicators of environmental and habitat transformation, and also include key species for signifying areas and faunas that require priority protection. Monitoring techniques, especially for insect eggs, are often labour intensive and time consuming. A study was conducted to determine the preferred oviposition site of Chrysoperla spp. on maize plants to facilitate time–effective searching for eggs of these beneficial insects. Furthermore we determined if the presence of aphids on plants influenced Chrysoperla spp. oviposition preference. Another study was conducted to evaluate the effect of indirect exposure of C. pudica to Cry 1Ab protein, through healthy Bt–maize feeding prey, on its biology. Daily flight activity patterns and the height at which chrysopid adults fly above the crop canopy were also determined, as well as the movement of adult Chrysoperla spp. between maize fields and adjacent headlands. A clear spatial oviposition pattern was observed on maize plants and oviposition was not random as reported in earlier studies. This data facilitates rapid monitoring of the presence of eggs in maize cropping systems and is also of use in general pest management. Choicetest data showed that females responded positively to host plants that were infested with aphids. Feeding studies in which C. pudica larvae were indirectly exposed to Bt–toxin at the 3rd trophic level, showed a limited effect of Bt–toxin on only a few of the parameters that were evaluated. The pupal period and percentage adult emergence of larvae exposed to an unusually high amount of Bt–toxin was significantly shorter and lower respectively than that of the control group. The overall result of this study, in which the possible effect of food quality (prey) was excluded, showed that Cry 1Ab protein had an adverse affect only on certain fitness components during the life cycle of C. pudica. However, since this study represented a worst–case scenario where diverse prey was not available to C. pudica, negligible effects is expected under field conditions where prey is more diverse. It was determined that chrysopids was most active between 16:00 – 23:00 and that they fly largely between 0.5 m – 2.5 m above ground level. An attempt was also made to quantify migration between different vegetations types. This part was terminated because of bad weather conditions at several occasions when the experiment was attempted. Chrysopids were never present in grassland vegetation, but an adjacent lucerne field maintained a large population. As the maize crop developed chrysopid population numbers increased inside the field, presumably originating from the lucerne field. / Thesis (M.Sc (Environmental Science))--North-West University, Potchefstroom Campus, 2011.

The diploma thesis studies accuracy of cheap GPS devices intended for mobile mapping in the landscape. Methodlogy for testing the accuracy of two GPS devices was established on the base of studied literature and apllied to two different GPS devices. The first device is PDA ASUS A639 connected by Bluetooth with external GPS reciever Navilock BT-338 and the second one is PDA ASUS A639 using its inbuilt GPS chipset. The result of testing is firstly comparison of accuracy of these two GPS devices and secondly the elements, which influnce their accuracy the most. The database of results is large enough to make some general conclusions concerning the accuracy of different GPS devices and their usage in the process of mobile mapping.

A broca-da-cana Diatraeasaccharalis(Fabricius) é uma das pragas-alvo do milho geneticamente modificado que expressagene(s) que codifica(m) proteína(s) de BacillusthuringiensisBerliner(milho Bt) no Brasil. Para estabelecer estratégias proativas de manejo de resistência, os objetivos do presente trabalho foram (1)estabelecer linhas-básicas de suscetibilidade à proteína Cry1F de B. thuringiensisem populações de D. saccharalis coletadas nas principais regiões produtoras de milho no Brasil na safra de 2010/2011, (2) realizar monitoramentoda suscetibilidade de populações de D. saccharalis na safra 2011/2012 e (3) avaliar a atividade biológica do milho Bt (evento TC1507) em diferentes estádios fenológicos no controle de D. saccharalis em condições laboratoriais. Para a caracterização das linhas-básicas de suscetibilidade foram realizados bioensaios com a proteína purificada Cry1F aplicada superficialmente em dieta artificial.As CL50 de Cry1F estimadas variaram de 0,47 a 7,02 ng de Cry1F/ cm2 dieta artificial para as populações avaliadas (variação de ?15 vezes). Foi definida e validada a concentração diagnóstica de 112 ng de Cry1F/cm²,baseada na estimativa da CL99 das populações testadas para o monitoramento da suscetibilidade. A avaliação da atividade biológica de milho Bt (evento TC1507) foi realizada com dois híbridos (Pioneer 30F35 e Dow 2B688) nos estádios fenológicos V3, V6 e V9 e em duas épocas de plantio. Alta atividade de controle de D. saccharalis foi obtida para os dois híbridos de milho Bt nos diferentes estádios fenológicos e épocas de plantio. Portanto, verificou-se que a espécie D. saccharalis é altamente suscetível à proteína Cry1F. Contudo, a implementação de estratégias de manejo da resistência é de fundamental importância para preservar a vida útil da tecnologia de milho Bt como importante ferramenta em programas de MIP. / The sugarcane borer Diatraeasaccharalis (Fabricius) is one of the target pests of genetically modified maizeexpressinggenes that code for insecticidal proteins from Bacillus thuringiensis Berliner (Bt maize) in Brazil. To implement proactive resistance management strategies, we leaded studies (1) to establish baseline susceptibility to Cry1F protein from B. thuringiensis in populations of D. saccharalis collected from major maize production regions in Brazil during 2010/2011 growing season, (2) to leadsusceptibility monitoring in populations of D. saccharalis collected in 2011/2012 growing season, and (3) to assess the biological activity of Bt maize (event TC1507) at different growth stages forD. saccharaliscontrol under laboratory conditions. The baseline susceptibility wascharacterizedwith purified protein Cry1F applied superficially on artificial diet. The estimatesof LC50 of Cry1F ranged from 0.47 to 7.02 ng Cry1F/cm2of artificial diet for the populations evaluated (? 15-fold variation).A diagnostic concentration of 112 ng Cry1F/cm ² was defined and validated for monitoring the susceptibility based on estimation of CL99 of all tested populations. The biological activity of Bt maize (event TC1507) was assessed by using two hybrids (Pioneer 30F35 and Dow 2B688) at growth stages V3, V6 and V9 and two planting seasons. High level of D. saccharaliscontrol was obtained for the twoBt maize hybrids at different growth stages and planting seasons. Therefore, we conclude that D. saccharalis is highly susceptible to Cry1F protein. However, implementation of insect resistance management strategies is essentialin order to preserve the lifetime of Bttechnology as an important tool in IPM programs.

No description available.