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The response to host plant variation shapes the long-term success of phytophagous insects. Two gall-forming tephritid flies, Urophora affinis and U. quadrifasciata, oviposit in flower buds of Centaurea diffusa and C. maculosa (Asteraceae). Females of both fly species chose among plants, among groups of buds on plants, and among buds. Among plant choices were correlated with buds per plant. Among bud choices corresponded to larval developmental requirements. Insect attack led to gall formation, bud abortion, and reduced seed production. Bud abortion, caused by probing females, limited gall densities. Increased densities of U. affinis females relative to oviposition sites led to more U. affinis galls, increased bud abortion, fewer U. quadrifasciata galls, and fewer seeds. A temporal refuge for seed production was observed. Plants compensated only slightly for aborted buds. Bud abortion may increase the search time between successful ovipositions. A simulation model based on this premise implied that bud abortion may dramatically reduce total gall formation. Plant quality was manipulated in an attempt to shift three population limiting factors. Plants responded to fertilization and watering with an increase in bud numbers. Except for two year-site-treatment combinations, galls per developed bud did not differ significantly between treatments. Treated plants did not differ in their propensity to abort buds. U. affinis larvae developed faster in fertilized plants. Among year comparisons showed that the density of buds available for oviposition was limited by precipitation, non-random insect attack, and, in the longer term, by the reduction in seed production due to fly attack. Bud densities, in turn, limited gall densities. / Science, Faculty of / Zoology, Department of / Graduate

Thesis advisor: Jeffery A. Byers / Thesis advisor: Chia-Kuang Tsung / Homogeneous catalysts are advantageous in selective catalysis due to the well-defined active site at the molecular level. The poor recyclability, bimolecular aggregation, and undesired poison resistance of homogeneous catalysts hinder further industrial application despite the controlled reaction pathway due to the homogeneous environment. On the other hand, heterogeneous catalysts are preferred in industry due to their high recyclability and high activity. Yet, poor selectivity due to undefined active sites is a drawback. The construction of a host-guest system where a molecular level catalyst is incorporated into the Metal-Organic Framework (MOF) provides a promising solution to bridge those two fields. This composite maintains the advantages of homogeneous and heterogeneous catalysts and overcomes the disadvantages. However, finding an incorporation method that is versatile with minimum synthetic modification of the host and guest remains one of the challenges. In the first part of this dissertation, a new concept called “aperture-opening encapsulation’’ is introduced for incorporating large and diverse guest molecules into MOFs without changing the identity of either the guest or MOF. The approach capitalizes on the existence of linker exchange reactions, which, as our kinetic studies show, proceed via competition between associative and dissociative exchange mechanisms. The second part describes how this method is applied to incorporate a molecular catalyst into the cavity of UiO-66 for the hydrogenation of carbon dioxide to formate, which is a useful application for energy related industry. The developed hybrid composite showed the ability to be recycled, showed no evidence of bimolecular catalyst decomposition, and was less prone to catalyst poisoning. These results demonstrate for the first time how the aperture-opening process resulting from linker dissociation in MOFs can be utilized as a strategy to synthesize host-guest materials useful for chemical catalysis. After the establishment of the hybrid catalyst, the last part of the dissertation describes our efforts into the investigation of mass transport in catalysis. The understanding of the interaction between the host-guest is beneficial for the development of biological analogs in the future. / Thesis (PhD) — Boston College, 2019. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Chemistry.

Economic benefits obtained from Flagellaria guineensis, a climbing bamboo, by local people received attention in previous studies but little is known about its regeneration ecology in three different forest stand conditions, i.e. forest edges, forest gaps and mature closed-canopy stands. In the Eastern Cape of South Africa the species grows in the Transkei Coastal Forests. The main aim of this study was to assess the regeneration ecology of F. guineensis in those forests. The specific objectives were to describe the phenological state that would influence the flowering, fruiting and growth of the species, and to compare the culm (stem) development from the rhizome between the different forest stand conditions. Phenological comparison was done in forest edge and forest interior conditions two forests. Rating scales were applied to determine the phenological states of the presence and amount of flower buds, open flowers, fruits, shoots and seedlings. Development of F. guineensis was assessed by sampling clusters in the three different forest stand conditions in three forests. The observation made in two Transkei Coastal Forests indicate that F. guineensis regenerates by producing seed, new vegetative shoots from rootstocks and also shoots at the growing tips. The flowering and fruiting period occurred only in the rainy season in Mtambalala forest but both rainy and dry seasons in Bulolo forest. More flowers and fruits of F. guineensis were found in Bulolo forest and in the forest edge (where F. guineensis is able to form tangles on the canopy of its host tree) respectively. This climbing bamboo clings on any plant around it for support and forms tangles on the canopy of its host in forest edges with no direct damage caused to host trees. The production of seedlings, shoots from the rhizome and shoots at the growing tips was constant during the study period in both study sites. The growth pattern of F. guineensis was different when comparing the three Transkei Coastal Forests studied. Manubi forest was found to have clusters and culms with the highest diameters and length compared to Mtambalala and Mnenga forests. There was a significant difference in culm diameter and length of F. guineensis between all three forests, whereas cluster diameter and number of culms per cluster were not influenced by forest stand conditions. F. guineensis clusters were common in the forest edges or gaps, and formed tangles in the canopy of their host trees. The described pattern of growth of F. guineensis contributes to recovery of the forest edges or gaps by restricting easy movement in and out of the forests. Several recommendations were made for harvesting of culms for basketmaking, such as: it should be done with care to reduce tangles in the forest and tree canopies; it must take place during the dry season, when the culms in a cluster are not flowering or fruiting; and studies are needed on the growth rate of seedlings and their growth into the forest canopy and how the bamboo can be cultivated outside the forest for better production of culms. / Dissertation (MSc)--University of Pretoria, 2017. / SAFCOL / Microbiology and Plant Pathology / MSc / Unrestricted

BACKGROUND: Graft versus host disease (GVHD) is a significant cause of morbidity and mortality following stem cell transplantation. Donor T cells are thought to be the main mediators of this disease, although we have recently identified that host T cells are present and active during acute GVHD suggesting contributions from both donor and host T cells. Whether both donor and host T cells can survive GVHD and coexist harmoniously after disease resolves is unknown. OBJECTIVE: The goals of this thesis are two-fold: (i) to study T cell chimerism in post-GVHD skin and (ii) to understand what effect, if any, treatment has on T cell chimerism in skin. METHODS: Acute GVHD and post-GVHD skin samples were obtained from male patients that had been transplanted with female donor cells. Chimerism was assessed using fluorescence in situ hybridization for the X and Y chromosomes concurrently with immunofluorescence staining for CD3, a T cell marker. Regulatory T cells were stained by immunofluorescence for CD3, CD4 and Foxp3. Medical record data was collected for all patients. RESULTS: We found that the percent of host T cells decreased significantly after resolution of acute skin GVHD compared to during active acute skin GVHD in skin samples obtained from five male patients that had been transplanted with female donor cells. The T cell composition in these patients in post-GVHD skin was primarily donor. We identified chimerism shifted toward donor T cells in patients treated with systemic steroids and this correlated with an increased number of donor T cells infiltrating into skin rather than a decrease in the number of host T cells in skin. With regard to frequency of Tregs, there was no significant difference between the group that had been treated with systemic steroids prior to biopsy and the group that had not. CONCLUSIONS: We discovered that donor chimerism predominates in post-GVHD skin and in active skin GVHD of patients who received systemic steroids, suggesting a role of donor cells in acute GVHD resolution. We were not able to identify a higher frequency of regulatory T cells in the treatment group. It is possible that the Treg recruited to skin by steroid treatment is Foxp3 negative, and therefore missed by our staining approach. The use of another marker is required for future studies.

Parasitic wasps have a wide range of specific developmental interactions with their hosts due to a close "parasitoid-host" relationship and that allows the study of many ecological and evolutionary questions. In our work, we focused on the parasitoid-host interactions in the parasitic wasp Anaphes flavipes (Förster, 1841) (Hymenoptera: Mymaridae). Because A. flavipes show a high variability of morphology and size, they have been repeatedly described as a new species in the past. Thus, we first redescribed the species and we compared the variability of some morphological structures for wasps from different localities (Paper 1). The high variability of the body size of wasps is reviewed in the second article, where we propose that females of A. flavipes do not decide according to the generally known "trade-off" scheme, if they will have more smaller offspring or fewer bigger offspring. In fact, the number of offspring depends on the body size of the female ("body size-fitness" hypothesis), which determines the variable reproductive strategies of mothers (the number of individuals that are laid into one host by a single female) (Paper 2). The third manuscript deals with the reproductive strategy of gregarious parasitoids. The reproductive strategy does not have to be stable; in the case of A....

This thesis first investigates within-host HIV models for the acute stage. These models incorporate the immune responses and helper T cells produced from the activation of naive CD4 T cells. Because both naive CD4 T cells and helper T cells are susceptible classes, backward bifurcation and bistability may occur. We start with a simple model that ignores the CD8 T cell dynamics, then extend it to include this dynamics. We also extend our model to consider the latent infection of naive CD4 T cells. Backward bifurcation occurs in all these models. We numerically investigate the stability of viral equilibria, and show the bistability caused by backward bifurcation. Increasing the inflow of CTLs prevents the backward bifurcation. With a large homeostatic source of healthy naive CD4 T cells, the disease is easier to establish when the basic reproduction number is less than one. Reducing the reproduction number below one is not sufficient to control the infection of HIV. Secondly, this thesis investigates the development of AIDS caused by viral diversity, as proposed by Wodarz et al. using a model that does not include the details of immune responses. We extend their model to include density dependence, and show that the viral load increases with viral diversity. To study if this result still holds with more realistic HIV dynamics, we incorporate viral diversity into our first model. We conclude theoretically that the total viral load is positively correlated with the number of viral strains, and viral diversity can drive the development of AIDS. We also find that the total CD4 T cell count does not always decrease with viral diversity. Thus further investigation is needed to fully understand the development of AIDS. / Graduate

Liptáková, M., Competency model of the selected management function in the hotel. Diploma thesis. Brno: Mendel University, 2018. This diploma thesis deals with the creation of competency model of selected management function in the hotel. Theoretical part deals with the description of the management, competencies and competency model. Practical part consists of analysis questionnaire research, in-depth interviews, evaluation of hypotheses and subsequently creation of competency model.

Indiana University-Purdue University Indianapolis (IUPUI) / Acute graft-versus-host disease (aGVHD) hinders the efficacy of allogeneic hematopoietic cell transplantation (HCT). Plasma levels of soluble serum stimulation-2 (sST2) are elevated during human and murine aGVHD and are correlated to a type 1 T cell response. Membrane-bound ST2 (ST2) on donor T cells has been shown to be protective against aGVHD. ST2 signals through the adapter protein myeloid differentiation primary response 88 (MyD88). The role of MyD88 signaling in donor T cells during aGVHD remains unknown. We found that knocking out MyD88 in the donor T cells protected against aGVHD independent of interleukin 1 receptor (IL-1R) and toll-like receptor 4 (TLR4) signaling, both of which also signal through MyD88, in two murine HCT models. This protection was entirely driven by MyD88-/- CD4 T cells, leading to a decreased type 1 response without affecting T cell proliferation, apoptosis, or migration. In our aGVHD models, loss of intrinsic MyD88 signaling is not responsible for the observed protection. However, transplanting donor MyD88-/- T conventional cells (Tcons) with wild type (WT) or MyD88-/- T regulatory cells (Tregs) ameliorated aGVHD severity and lowered aGVHD mortality. Transcriptome analysis of sorted MyD88-/- CD4 T cells from the intestine ten days post-HCT showed lower levels of Il1rl1 (gene of ST2), Ifng, Csf2, Stat5, and Jak2, among others. Decreased sST2 was confirmed at the protein level with less secretion of sST2 and more expression of ST2 compared to WT T cells. Transplanting donor ST2-/- Tcons with WT or ST2-/- Tregs mirrored observations when using donor MyD88-/- Tcons. This suggests that Treg suppression from lack of MyD88 signaling in Tcons during alloreactivity uses the ST2 but not the IL-1R or TLR4 pathways. The results of our study confirm that ST2 represents an aGVHD therapeutic target that spares Treg function.

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