Zugl.: Karlsruhe, Univ., Diss., 2009 / Hergestellt on demand. - Zusätzliches Online-Angebot unter http://uvka.ubka.uni-karlsruhe.de/shop/isbn/978-3-86644-465-2

Biological invasions have increased dramatically in the past centuries and are one of the greatest threats to biodiversity today. Invasions occur when organisms are introduced at a location to which they are non-native, and they reproduce and spread, causing damage to the environment. Chromolaena odorata, a herbaceous shrub from the Americas, is one of the most widespread and problematic invasive plant species in the tropics and sub-tropics. The plant is a serious problem in South Africa, where invasive species threaten the nation’s biodiversity and limited water supply. This study combined transect monitoring data of C. odorata with ecological and clearing management data to assess the efficacy of an invasive plant clearing program over its decade of operation in the Hluhluwe-iMfolozi reserve in KwaZulu-Natal, South Africa. Densities and local extent of the C. odorata invasion were significantly reduced during the period of operations of the clearing program. Seasonal effects impacted clearing efficacy, namely a reduction in efficacy during the seed dispersal period. Effort and fire frequency were positively associated with clearing success, and rainfall negatively associated with clearing success. Excluding the northern section of the reserve, where the invasion progressed over the whole landscape, observations of C. odorata were closer to watercourses than randomized points, indicating a water limitation for invasion in most of the park. Management implications drawn from the results include halting clearing during seed-drop months, giving extra attention to areas with more rainfall and other water availability, and incorporating fire with other clearing methods where possible.

Invasive organisms are one of the major threats to the ecological integrity of aquatic systems in the 21st century. Among the most notorious and important aquatic invasive organisms are the dreissenid mussels, Dreissena polymorpha and D. rostriformis bugensis, which having originated in the Ponto-Caspian region are now common in many parts of Europe and North America. Dreissenids have large impacts on many aspects of lentic ecosystem functioning, the sum of which is thought to lead to the translocation of biological production from the pelagic to the littoral zones of lakes. In this thesis I explore the effects of dreissenids on the nearshore zones of large lakes, investigate the mechanisms by which dreissenids couple the pelagic and nearshore zones of lakes and attempt to elucidate the factors affecting the strength of the dreissenid-mediated connection between the pelagic and littoral zones. The effects of invasive organisms on an aquatic ecosystem will depend, in part, on the distribution and biomass of the invasive organisms in the system. In chapter 2 I present the results of a lake-wide survey of the distribution of invasive dreissenid mussels in Lake Simcoe, Ontario and discuss some of the factors that shape their distribution pattern in the lake. Dreissenid biomass averaged 27.2 (±24.3 SD) g shell-free dry mass (SFDM)/m2 in the main basin of Lake Simcoe and 12.4 (±16.9 SD) g SFDM/m2 in macrophyte-dominated Cook’s Bay. I argue that water movement is an important determinant of dreissenid distribution, both through catastrophic disturbance in shallow water and through non-catastrophic effects on substrate distribution and possibly food supply rates. In areas of dense macrophyte growth, mussel abundance was shown to be associated with that of preferred macrophyte taxa, in particular with that of Ceratophyllum demersum. I used the results of my survey and the relationships between environmental variables and dreissenid biomass to estimate the total biomass of dreissenids in Lake Simcoe: 12,000 tonnes SFDM. Most of the dreissenid biomass in Lake Simcoe was concentrated in the nearshore zone, where dreissenids would have maximal impacts on littoral biological production. One of the effects of the dreissenid invasion into the Laurentian Great Lakes appears to be a resurgence in the abundance of the nuisance alga Cladophora glomerata which experienced a marked decline following phosphorus abatement in the late 1970s and early 1980s. A subsidy of bioavailable phosphorus excreted by dreissenid mussels could be an important mechanism facilitating the growth of C. glomerata. In chapter 3, I describe a survey of dreissenid distribution and abundance followed by in situ experiments designed to measure dreissenid phosphorus excretion rates. Average dreissenid mussel abundance in our study area was 3674 (±2233 SD) individuals/m2, with an average biomass of 52.2 (±29.0 SD) g of shell free dry mass/m2. The mussels excreted bioavailable soluble reactive phosphorus (SRP) at an average rate of 7.0 μg SRP/g shell free dry mass/hour, contributing about 11 tonnes of SRP to the study area over the C. glomerata growing season. Dreissenids appear to be an important source of recycled bioavailable phosphorus to the littoral zone, potentially supplying more soluble reactive phosphorus to the study area than local watercourses and waste water treatment plants, and more phosphorus than is required to sustain local C. glomerata growth. Dreissenid establishment in many systems coincides with increases in the abundance and diversity of littoral benthic invertebrates and with changes to community composition of the benthos. Currently, there is a lack of long-term studies of the impact of dreissenid mussels on hard-substrate inhabiting littoral benthos. In chapter 4 I compare the littoral benthos of Lake Simcoe, Ontario just prior, and 14 years following the establishment of dreissenids in the lake. Densities of non-dreissenid invertebrates on hard substrata increased by nearly 50 times, from an average of 367.9 (±460.8 SD) individuals/m2 in 1993 to an average of 16,706.4 (±10,204.5 SD) individuals/m2 in 2008. The taxonomic diversity of the benthos increased significantly. The distribution of benthic organisms also changed; the numerical abundance of benthos has become more even across depths and sites, as has community composition. I suggest that in addition to increasing resource availability to benthic organisms dreissenids have also caused a homogenization of the littoral habitat by increasing the evenness of the distribution of food and habitat resources. The changes in the littoral benthic community in Lake Simcoe likely have wide-ranging implications to higher trophic levels and the cycling of energy in the lake. In addition to impacting nutrient cycling and the benthic invertebrate communities of littoral zones, dreissenid mussels can have large effects on food webs and energy cycling. In chapter 5 I used stable isotope analysis of pre- and post-dreissenid components of the nearshore food web of Lake Simcoe, Ontario to determine how dreissenids affected food sources and energy flow in the littoral zone of Lake Simcoe. Results suggest that the post-dreissenid food web relies about equally on two energy sources: dreissenid biodeposits (redirected pelagic primary production) and littoral benthic primary producers. Although the relative importance of pelagic and benthic primary production to benthic organisms has not changed much following dreissenid establishment, the absolute importance of both increased considerably in the post-dreissenid littoral zone: the large increase in invertebrate biomass that followed dreissenid establishment means that the amount of both pelagic and benthic primary production needed to sustain post-dreissenid organisms had to increase considerably. The results of this chapter suggest that dreissenids increase the availability to food to littoral organisms by redirecting pelagic primary production to the benthos and by stimulating littoral benthic primary production. The impacts of dreissenids on littoral benthic organisms probably have large effects on littoral and pelagic fish communities of lakes. Dreissenid mussels translocate biological production to the benthos by stimulating benthic primary production through nutrient excretion and increases in water clarity, by increasing habitat availability for benthic organisms and by biodepositing pelagic material that becomes available to benthic organisms and the fish that feed on them. I argue that hydrodynamic factors are important in controlling the strength of the dreissenid-mediated pelagic-littoral connection in lakes. Because hydrodynamics relate to lake size, a relationship between lake size and the ability of dreissenids to translocate production the littoral zone can be postulated, where dreissenid effects are maximal in intermediate-sized lakes.

The mechanisms that allow invasive species to flourish in novel habitats are poorly understood. A. petiolata (Alliaria petiolata) is an invader of North American forest edge and understory communities. A. petiolata’s success may result from high competitive ability due to its suppression of mycorrhizal fungi used by other species. In a greenhouse experiment, I grew 27 target species in the presence and absence of A.petiolata in soil with and without a history of A. petiolata. I found that soil with a history of A. petiolata had depleted plant available nitrogen and reduced mycorrhizal fungal colonization of target species. A. petiolata competition suppressed the growth of target species less in soils with than without A. petiolata history. Furthermore, I found that tall plants with finer roots more effectively suppressed the growth of A. petiolata. My results suggest that soil feedback effects do not improve A. petiolata’s competitive ability and are unlikely to contribute to A. petiolata invasion.

The neotropical semi-woody perennial shrub Chromolaena odorata (L.) King and Robinson (Asteraceae: Eupatorieae) has become a serious invasive weed in the sub-tropical regions of southern Africa, resulting in the initiation of an insect biocontrol research programme at Cedara in the KwaZulu-Natal province. The programme has experienced difficulties in growing and maintaining healthy potted C. odorata plants for research, for almost ten years. In an attempt to identify possible causes of mortality, plants were grown on elevated grids in two trials; (winter-spring 2003) and (autumn-winter 2004) in Durban (subtropical region, within the natural range of C. odorata) and Cedara (temperate region, outside its natural range). Plants that established at all sites, in Trials 1 and 2, did not display any visual symptoms associated with mortality; however, results from Trial 1 indicated that plants grown in a tunnel at Cedara were physiologically stressed evidenced by lower transpiration rates despite higher vapour pressure deficits, compared with plants grown in a tunnel in Durban. Environmental stress was further indicated by the chlorophyll fluorescence ratio and a change in allocation of total non-structural carbohydrate (TNC) within Cedara-grown plants compared with Durbangrown plants. An attempt to relate mortality symptoms of unhealthy C. odorata plants with TNC content of the roots was unsuccessful but unhealthy plants had lower levels of N, P and K than healthy plants. Although mortality seem to be exacerbated by pathogenic fungi in saturated soil, infection was reduced by treating the soil with Previcur N and Benlate drench. Morphological adaptations of plants exposed to waterlogged soils include hypertrophied lenticels and new lateral roots; these were observed on the stem base of unhealthy C. odorata plants placed on the ground, that had reached a critical stage of die-back or had died back and re-sprouted. Examination of the root anatomy of C. odorata plants indicated an absence of cortical aerenchyma (interconnected system of air spaces), which may explain plant mortality in waterlogged pots wherein levels of oxygen in the soil may be reduced. C. odorata stock plants at Cedara have been placed on elevated grids since August 2004 and two years later plant mortality has been significantly reduced. Presently, the only feasible option is to grow potted C. odorata plants on elevated grids at Cedara because this allows for adequate drainage, aeration of soil and air-nipping of roots, and spacing plants on the grids also improves penetration of light. / Thesis (M.Sc.)-University of KwaZulu-Natal, Durban, 2007.

ABSTRACT Background Calprotectin is a protein found in the cytoplasm of neutrophile granulocytes. In the course of inflammatory bowel disease (IBD), calprotectin is released during chronic inflammation in the gut. Activation of neutrophils during the inflammation is followed by activation and secretion of pro-inflammatory molecules such as calprotectin. Calprotectin is stable in stool up to 7 days and can therefore be used as a non-invasive marker for diagnosis, treatment and measurement of the disease activity in patients with IBD. The most common method for analysis of calprotectin concentration is ELISA. This method is time-consuming and many manufactures have therefore developed rapid tests as a faster alternative for quantification of calprotectin in stool. Aim The aim of the study was to evaluate one ELISA and one rapid test from the same manufacture compare the data with the existing ELISA-method used in the laboratory for routine analysis. Methods A rapid test (CalFast) and an ELISA method (CalPrest) from Eurospital, were used for analysis of calprotectin in stool. These two methods were compared with known concentrations of calprotectin obtained by the ELISA method from Bühlmann used in the routine work.  Results The results showed poor correlation between the rapid test and the ELISA method. Furthermore, the comparison between the two ELISA-methods showed a poor correlation. Conclusion Evaluation of the two new methods showed poor correlation with the existing ELISA method from Bühlmann. Evaluation of the rapid test did not show any correlation with the two ELISA methods and the data cannot be trusted. It is difficult to conclude which of the two ELISA methods gives accurate results due to the absence of an international standard.

Globally, breast cancer is the most abundant cancer form in women, in Sweden about 20 women are diagnosed with breast cancer every day .Interactions between genetic and external factors are the contributing factors while metastasis formation is the leading cause of death. Cancer is in need of vessels,to get the nutrients and oxygen it needs in order to survive. Therefore,the aim of the study is to analyze and compare the groups of high and low differential cancer vessels of the respective form, and to see if any type contained more vessels than the other. The study is based on 20 invasive ductal breast cancer samples, ten of them were high differentiated and the other ten were low differentiated. To assess the number of vessels, immunhistochemical staining with CD31 antibody was performedCD31 is an adhesion molecule present on endothelial cells. The group of low differentiated gradebreast cancer tissue had significantly more vessels compared with the high differentiated breast cancer tissues. To prove these test results, more cancers must be analyzed.

Elevated intracranial pressure (ICP) in closed head injury may lead to a vegetative state and even death. Current methods available for measuring ICP may cause infection, haemorrhage or not reliable. A patient-specific correlation between ICP and an external vibration response was used for ICP evaluation, which based on finite element (FE) modeling. In FE modeling, a two dimensional FE model of human head was built in ANSYS. Geometry information was obtained from a magnetic resonance image of the human head, while the material properties were acquired from literatures. Vibration responses, e.g., displacement, velocity, acceleration and equivalent strain, were obtained for applied ICPs in FE analyses. Correlations between ICP and vibration responses were established. Effects of impact magnitude and impact duration were studied. Response sensitivity was defined to find a vibration response that is sensitive to ICP change. A procedure based on response sensitivity was proposed for ICP evaluation.

Common teasel (Dipsacus fullonum L.) has become an aggressive invasive species throughout most of North America, invading roadsides, ditches, rights of way, pastures, and natural areas. This study examined three herbicides used to control common teasel: 1) BK 800, a 2,4-D based broad-leaf herbicide mixed in diesel fuel; 2) Glyphomax® a non-selective glyphosate-based product mixed in water with 5 mL/L of a non-ionic surfactant (Nu-Film®-IR) added; and 3) Transline®, a clopyralid based broad-leaf herbicide used for non-crop areas with 5 mL/L of the Nu-Film®-IR. The herbicides were applied in three concentrations taken directly from the label specifications: the low end, the high end, and the midpoint between the low and high ends. Plant rosette counts taken two weeks after application were compared to counts taken earlier to create a "survival ratio." The majority of the applications resulted in total kill of all common teasel rosettes. Ratios were compared among all treatment groups and the control. All herbicide treatments resulted in significantly (p<0.001) more kills than the control. The different concentrations of each treatment were compared against each other to determine the optimum concentration for common teasel control. The 2 mL/L concentration of Transline®, the 13 mL/L concentration of Glyphomax® and the 55 mL/L of BK 800 were the most effective treatments. There was no significant difference among the efficacies of the three above herbicides. This study provides the first known quantitative study of herbicidal control of common teasel, and it should serve as a starting point for future studies on controlling this invasive plant. / Department of Natural Resources and Environmental Management

Glaucoma is a group of optic nerve degenerative diseases, which leads to gradual and permanent vision loss. Recent developments in the field of gene therapy have proposed increasingly promising treatments for glaucoma, in the form of delivery of neuro-protective or neuro-regenerative genes to the retina. Despite these developments, there are concerns related to the biocompatibility and invasiveness of common gene delivery systems, since they are commonly mediated by viral gene carriers and invasive administration methods. Non-viral gene delivery systems offer a safe and increasingly efficient alternative to deliver therapeutic genes to the retina. An example of these systems is gemini-phospholipid nanoparticles (GL-NPs), which have been successfully used to deliver genes in similarly challenging anatomical settings, such as the skin. The objective of this thesis is to demonstrate the potential of GL-NPs, as candidate gene delivery vehicles for topically administered genes, targeted to the retina. The dicationic gemini surfactant, 12-7NH-12 was used, along with the helper lipids, 1, 2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE), and 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), to prepare various types of GL-NPs, and assess their transfection efficiency in the rat retinal ganglion cell line (RGC-5). The transfection efficiency was evaluated using flow cytometry, as a function of several physical and chemical parameters of GL-NPs. These include a range of charge ratios (5:1 to 15:1 ????), helper lipid composition (several DOPE: DPPC ratios), order of assembly (plasmid-gemini + lipid versus gemini-lipid + plasmid), and manufacturing method of helper lipid vesicles (thin film versus high pressure homogenization method). Size and zeta (??) potential characterization of GL-NPs was carried out in parallel, using dynamic light scattering, to relate the physical parameters of GL-NPs to their respective transfection efficiency. A comprehensive toxicological evaluation was undertaken to assess the extent of GL-NP???s toxicity in RGC-5 cells, using the resazurin-based PrestoblueTM cell toxicity assay. Optimized GL-NPs were used to induce expression of the brain derived neurotrophic factor (BDNF) in RGC-5 cells, and were assessed in terms of their capacity to induce neurite outgrowth. Quantification of neurite outgrowth was carried out by measuring average neurite length in RGC-5 cells, by confocal microscopic imaging of immunostained neurites. Furthermore, confocal microscopic studies were carried out to assess the extent of GL-NP???s corneal permeation in a 3-D human corneal epithelial (HCE) model. A parallel toxicological evaluation was completed to ensure GL-NP???s biocompatibility with the corneal epithelial cells. Finally, GL-NP biodistribution pattern and gene transfer capacity was assessed in a mouse model, following topical and intravitreal administration. The transfection efficiency in RGC-5 cells, which ranged between 2.1 ?? 0.3% and 14.5 ?? 1.4%, was highly dependent on GL-NP???s charge ratio, helper lipid composition, order of assembly, and manufacturing technique. GL-NPs at 10:1 ???? charge ratio, assembled with homogenized DOPE (25%)-DPPC (75%) helper lipid vesicles, in the plasmid-gemini + lipid order, mediated the highest transfection efficiency in RGC-5 cells. These GL-NPs had a size of 222.8 ?? 4.2 nm and a ?? potential of +33.5??2.9 mV. Optimized GL-NPs were highly biocompatible with both RGC-5 and HCE model cells, with viability values ranging between 94.8 ?? 6 % to 100 ?? 3.4 %. Assessment of corneal permeation showed that GL-NPs were able to bind to the corneal epithelial surface and achieve a moderate permeation depth (35-40 ??m), following topical application in the HCE model. Intravitreal injection of the non-viral GL-NPs in mice has successfully led to their localization within the nerve fiber layer (NFL) of the retina. Finally, GL-NPs were non-invasively delivered to several anterior chamber tissues, including the limbus, the iris and conjunctiva, following topical administration. GL-NPs offer several advantageous features critical to topical and intravitreal ocular administration of gene carriers, including in vitro corneal binding and effective biodistribution following in vivo topical and intravitreal administration, high biocompatibility, and a highly tunable transfection efficiency. The current data presents 12-7NH-12 GL-NPs as a promising candidate for ocular gene therapy applications.