The purpose of these studies was to determine whether lactogen-dependent Nb2-11c cells and lactogen-independent Nb2-SP cells differ with respect to morphology and autocrine growth control. To this end, the ultrastructural and surface morphology of both Nb2 cell lines was analyzed and the autocrine growth modulatory activity of Nb2 cell conditioned medium (Nb2-CM) was determined. The autocrine growth inhibitory activity of Nb2-CM was biologically characterized and attempts were made to biochemically characterize and purify the Nb2 cell autocrine growth inhibitor as well as to determine its mechanism of action. Quantitative analysis of transmission electron micrographs reveals that the ultrastructural morphology of lactogen-dependent Nb2-11c cells differs from that of lactogen-independent Nb2-SP cells. Nb2-11c cells exhibit a greater incidence and volume density of nuclear pockets, whereas the incidence and volume density of lipid droplets is greater in the Nb2-SP cell line. Surface feature of Nb2-11c and Nb2-SP cells, as examined with scanning electron microscopy, and indistinguishable. Nb2-11c and Nb2-SP cells share a common mode of growth control in the form of constitutive secretion of an autocrine inhibitory factor. Medium conditioned by either Nb2-11c or Nb2-SP cells inhibits the growth of both cell lines. Nb2-CM-mediated growth inhibition is dose-dependent and reversible. Nb2-CM does not induce quiescence or cell death, but rather, causes a delay in the progression of cells through all phases of the cell cycle. Nb2 cell proliferation stimulated by a variety of mitogens is inhibited by Nb2-CM. Nb2-CM also has the ability to inhibit the growth of normal rat splenocytes as well as MCF-7 human breast cancer cells. Biochemical analysis of Nb2-CM was equivocal; however, indirect evidence suggests that the autocrine growth inhibitory factor produced by Nb2 cells may be a prostaglandin or another arachadonic acid metabolite since the growth inhibitory activity of Nb2-CM is reduced when CM is prepared in the presence of indomethacin. Interestingly, levels of prostaglandin F₁(α) are elevated in CM-treated culture supernatants. Examination of other signal transduction systems in Nb2 cells suggests that neither cAMP activation, polyamine biosynthesis, nor protein kinase C activation mediate or influence the inhibitory effect of Nb2-CM.

Receptor-activated phosphatidylinositol (PtdIns) hydrolysis was examined in AR42J rat pancreatic acini. Cholecystokinin-octapeptide (CCK₈) and bombesin induced a dose-dependent accumulation of [³H] inositol monophosphate ([³H]InsP₁). Manganese (Mn²⁺), a known calcium channel blocker, did not alter basal PtdIns hydrolysis. In contrast, when added 5 minutes prior to the addition of agonists for 60 minutes, Mn²⁺ markedly inhibited secretagogue-mediated [³H]InsP1 formation. Mn²⁺ also attenuated the CCK₈-mediated increase in biologically active inositol 1,4,5-trisphosphate and inositol 1,3,4,5-tetrakisphosphate. These inhibitory effects of Mn²⁺ were mimicked by lanthanum and by EGTA. Addition of calcium to EGTA-treated cells abolished the inhibitory effects of extracellular calcium depletion. Mn²⁺, La³⁺ and EGTA exerted similar inhibitory effects on PtdIns hydrolysis in pancreatic acini. These findings suggest that receptor-activated calcium influx is required for full activation of the CCK₈-mediated signal transduction pathway that is coupled to PtdIns hydrolysis.

The present study investigates the phenomenon of organisational acculturation of Egyptian Host Country National middle managers working in three foreign subsidiaries of US, UK, and Swedish MNCs. Host Country National staff (HCNs) are those who work in foreign subsidiaries established in their own countries. HCNs are exposed to the organisational culture of the MNC which is affected by the national culture of the parent company. Accordingly, the concept of cultural adaptation, or organisational acculturation, has been stressed as an essential process for MNCs to deal with problems arising from cultural differences and achieve cross-cultural effectiveness. The topic of the present study is an understudied topic and only few studies addressed the acculturation of HCNs, most of which within the context of Asian-only cultures. The study used a multiple case design and the data were collected using a mixed methods design in which both quantitative and qualitative methods were used. The study was conducted in two phases; the first phase was to compare the work values of the Egyptian middle managers and their UK, US, and Swedish expatriates using a questionnaire on work values, in order to find similarities or differences in work values between the Egyptian managers and their expatriates. To measure the work values of the host national culture, the study used a comparison group of Egyptian middle managers in three local Egyptian firms. In the second phase, in-depth interviews and observation were conducted with a number of Egyptian middle managers who were found to have work values significantly similar to or different from their expatriates work values in the three subsidiaries. This phase was conducted in order to further examine the acculturation phenomenon, and to understand the influence of the Egyptian national culture and the type of control mechanisms used by MNCs on the acculturation process. The results showed that some acculturation effects might have occurred in some work values of Egyptian managers, while other work values might have not been influenced due to the strong effect of the Egyptian national culture. Also, the study found that Egyptians needed both formal bureaucratic and informal cultural mechanisms of control, though with more stress on the formal bureaucratic ones.

The main purpose of this thesis was to give a general overview of the problem of child soldiers and their protection among international law conventions and among regional law agreements with the focus on the African continent. The use of child soldiers in armed conflict is qualified as one of the worst forms of child labour.The majority of child soldiers are active in Africa and, to a lesser extent, in the Middle East and Asia. Besides introduction and conclusion, the study consists of five chapters. The first chapter describes the protection of child soldiers on the international level. Therefore it is focused on individual conventions, especially on Geneva Conventions, Additional Protocols to the Geneva Conventions, the Convention on the Rights of the Child, the Optional Protocol to the Convention on the Rights of the Child on the involvement of children in armed conflict, the Optional Protocol to the Convention on the Rights of the Child on a Communications Procedure, but as well on the International Labour Convention No. 182 or the Rome Statute. The soft law represents Paris principles. Discussed is particularly the question of the age limit for child participation in armed conflict. The second chapter is concerned with the international control mechanisms, resulting from the above-mentioned...

Mammalian neurons exhibit extreme sensitivity to oxygen deprivation and undergo rapid and irreversible degeneration when oxygen supply is curtailed. Though several neuroprotective pathways are activated during oxygen deprivation, their analyses are masked by the complex series of pathological events which are triggered simultaneously. Such events can be analyzed in the anoxia tolerant fresh water turtle, which can inherently survive the conditions of oxygen deprivation and post-anoxic reoxygenation without brain damage. It is likely in such a model that modulation of a particular molecular pathway is adaptive rather than pathological. The major objective behind this study was to analyze the intracellular signaling pathways mediating the protective effects of adenosine, a potential neuromodulator, and its effect on cell survival by influencing the key prosurvival proteins that prevent apoptosis. In vivo and in vitro studies have shown that adenosine acts as a neuroprotective metabolite and its action can be duplicated or abrogated using specific agonist and antagonists. Stimulating the adenosine receptors using selective A1 receptor agonist N6-cyclopentyladenosine (CPA) activated the presumed prosurvival ERK and P13-K/AKT cascade promoting cell survival, and suppression of the receptor using the selective antagonist DPCPX (8- cyclopentyl-1,3-dipropylxanthine) activated the prodeath JNK and P38 pathways. The complex regulation of the MAPK's/AKT signaling cascades was also analyzed using their specific inhibitors. The inhibiton of the ERK and AKT pathway increased cell death, indicating a prosurvival role, whereas inhibiton of the JNK and p38 pathway increased cell survival in this model. In vitro studies have also shown a high Bcl-2/BAX ratio during anoxia and reoxygenation, indicating a strong resistance to cell death via apoptosis. / Silencing of the anti-apoptotic Bcl-2 gene using specific siRNA upregulated levels of prodeath BAX, thus altering the Bcl-2/BAX ratio and elevating cleaved Caspase-3 levels leading to increased cell death. Another promising neuroprotective target which we analyzed was Neuroglobin, which was induced during oxygen crisis and silencing this gene indicated that its plays a major role in modulation of ROS. This study strongly emphasizes the advantages of an alternate animal model in elucidating neuroprotective mechanisms and revealing novel therapeutic targets which could eventually help clinicians to design new stroke therapies based on naturally tolerant organisms. / by Gauri Nayak. / Thesis (Ph.D.)--Florida Atlantic University, 2009. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2009. Mode of access: World Wide Web.

The ubiquitin ligase Highwire is responsible for cell-autonomously promoting synapse formation in the Drosophila Giant Fiber system. highwire mutants show defects in synaptic function and extra branching at the axon terminal, corresponding to transient branching that occur in the course of giant synapse formation during metamorphosis. The MAP kinase pathway, including Wallenda and JNK/Basket, plus the transcription factor Jun, act to suppress synaptic function and axon pruning in a dosage sensitive manner, suggesting different molecular mechanisms downstream of the MAP kinase pathway govern function and pruning. A novel role for Highwire is revealed, regulating the giant fiber axon’s ability to respond to external cues regulated by Fos. When expression of the transcription factor Fos is disrupted in the post-synaptic TTMn or surrounding midline glia of highwire mutants, the giant fiber axons show a marked increase in axon overgrowth and midline crossing. However, synaptic function is rescued by the cell nonautonomous manipulation of Fos, indicating distinct mechanisms downstream of Highwire regulating synaptic function and axon morphology. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2014. / FAU Electronic Theses and Dissertations Collection

New neurons are continuously generated in the olfactory system of adult mice, including olfactory sensory neurons (OSNs) in the olfactory epithelium (OE) and interneurons, produced in the subventricular zone (SVZ) and migrated toward olfactory bulb (OB) along rostral migratory stream (RMS). The present study observed the effects of target neuron loss on the life-span and maturation of adult-born OSNs in the OE and on the proliferation, migration and differentiation of SVZ stem cells in the forebrain after eliminating bulb neurons. We found the life-span of newborn neurons in the absence of synaptic targets was shortened, but the timing of maturation was not delayed. In addition, SVZ cells continued to divide and migrate to the damaged bulb, and the migration of newborn cells in the RMS on the contralateral side was delayed at 2 weeks post-BrdU. Also, the proliferation of cells in dentate gyrus of the hippocampus was not affected by OB damage at 3 weeks post-lesion, though lesion affects occurred in the adult SVZ/RMS. / by Huan Liu. / Thesis (M.S.)--Florida Atlantic University, 2008. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2008. Mode of access: World Wide Web.

The primary purpose of this study was to examine the impact of acute highintensity interval Exercise (HIIE) on plasma cfDNA and IL-6 responses in obese and normal-weight subjects. Fifteen subjects (8 obese and 7 normal-weight) were recruited to participate in an acute HIIE protocol. Our results demonstrated a significant elevation across time in plasma cfDNA and IL-6 immediately following acute HIIE, with no difference between obese and normal-weight subjects. Furthermore, cfDNA was not correlated with IL-6 in response to acute HIIE in either group. These findings indicate that the obese state does not further exacerbate the release of acute HIIE-induced inflammatory mediators (cfDNA and IL-6), which suggests that HIIE training may serve as a time-effective exercise strategy to improve obesity-associated inflammation. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2017. / FAU Electronic Theses and Dissertations Collection

The rodent hippocampus is critical for processing spatial memory but its contribution to non-spatial, specifically object memory is debated. The cognitive map theory of hippocampal function states that the hippocampus stores relationships of goal locations (places) to discrete items (objects) encountered within environments. Dorsal CA1 place cells were recorded in male C57BL/6J mice performing three variations of the novel object recognition paradigm to define "object-in-context" representation of hippocampal neuronal activity that may support object memory. Results indicate, (i) that place field stability is higher when polarizing environmental cues are provided during object recognition; (ii) hippocampal place fields remain stable throughout the novel object recognition testing without a polarizing cue; and (iii) time dependent effects on stability when objects were dissociated from the context. These data indirectly support that the rodent hippocampus processes object memory, and challenge the view that "object-in-context" representations are formed when mice perform novel object recognition task. / by Herborg Nanna âAsgeirsdâottir. / Thesis (M.A.)--Florida Atlantic University, 2013. / Includes bibliography. / Mode of access: World Wide Web. / System requirements: Adobe Reader.

The function and role of PAK6, serine/threonone kinase, in cancer progressionhas not yet been clearly identified. Several studies reveal that PAK6 may participate in key changes contributing to cancer progression such as cell survival, cell motility, and invasiveness. Basedon the membrane localization of PAK6 in prostate and breast cancer cells,we speculated that PAK6 plays a rolein cancer progression cells by localizing on the membrane and modifying proteins linked to motility and proliferation. We isolated the raft domain of breast cancer cells expressing either wild type (WT), constitutively active (SN), or kinase dead PAK6 (KM) and found that PAK6 is a membrane associated kinase which translocates from the plasma membrane to the cytosol when activated. The downstream effects of PAK6 are unknown ; however, results from cell proliferation assays suggest a growth regulatory mechanism. / by JoAnn Roberts. / Thesis (M.S.)--Florida Atlantic University, 2012. / Includes bibliography. / Mode of access: World Wide Web. / System requirements: Adobe Reader.