This thesis is concerned with the usability of Raspberry Pi as the access point in the mobilebroadband network environment. The first part of the thesis is dedicated to Raspberry Pi itself;hardware required to set up WLAN and WAN; and to the analysis of suitable solutions forbandwidth aggregation, particularly the load balancing of mobile broadband connections andtheir aggregation into one logical link. The second part deals with the implementation of thesesolutions and subsequently with their testing and verification. The evaluation of results gives aninteresting outcome. Load balancing has proven to be resilient and feasible solution forbandwidth aggregation in the mobile broadband network environment where the speed, packetloss and jitter are of main concern. The second scenario, where the connections are bundled intoone logical link, has turned out to give variable results. Its performance is susceptible to thechanges in the mobile broadband network as the packets across the links in the bundle alternatein the round-robin fashion.

Primordial follicles are the first small follicles to appear in the mammalian ovary. Women are born with a fixed number of primordial follicles in the ovaries. Once formed, the pool of primordial follicles serves as a source of developing follicles and oocytes. The first aim of this thesis was to investigate the functional role of the intra-oocyte signaling pathways, especially the phosphatidylinositol-3 kinase (PI3K) and mammalian target of rapamycin complex 1 (mTORC1) pathways in the regulation of primordial follicle activation and survival. We found that a primordial follicle remains dormant when the PI3K and mTORC1 signaling in its oocyte is activated to an appropriate level, which is just sufficient to maintain its survival, but not sufficient for its growth initiation. Hyperactivation of either of these signaling pathways causes global activation of the entire pool of primordial follicles leading to the exhaustion of all the follicles in young adulthood in mice. Mammalian oocytes, while growing within the follicles, remain arrested at prophase I of meiosis. Oocytes within the fully-grown antral follicles resume meiosis upon a preovulatory surge of leutinizing hormone (LH), which indicates that LH mediates the resumption of meiosis. The prophase I arrest in the follicle-enclosed oocyte is the result of low maturation promoting factor (MPF) activity, and resumption of meiosis upon the arrival of hormonal signals is mediated by activation of MPF. MPF is a complex of cyclin dependent kinase 1 (Cdk1) and cyclin B1, which is essential and sufficient for entry into mitosis. Although much of the mitotic cell cycle machinery is shared during meiosis, lack of Cdk2  in mice leads to a postnatal loss of all oocytes, indicating that Cdk2 is important for oocyte survival, and probably oocyte meiosis also. There have been conflicting results earlier about the role of Cdk2 in metaphase II arrest of Xenopus  oocytes. Thus the second aim of the thesis was to identify the specific Cdk that is essential for mouse oocyte meiotic maturation. We generated mouse models with oocytespecific deletion of Cdk1  or Cdk2  and studied the specific requirements of Cdk1 and Cdk2 during resumption of oocyte meiosis. We found that only Cdk1 is essential and sufficient for the oocyte meiotic maturation. Cdk1 does not only phosphorylate the meiotic phosphoproteins during meiosis resumption but also phosphorylates and suppresses the downstream protein phosphatase 1, which is essential for protecting the Cdk1 substrates from dephosphorylation.

Darbo tikslas: Atlikti PG-3 ir RS virusų infekcijų epidemiologinius tyrimus Lietuvos galvijininkystės ūkiuose, nustatyti pasyvaus ir aktyvaus imuniteto trukmę bei išaiškinti imuninio atsako galimybes, naudojant skirtingus vakcinacijos būdus. Darbo uždaviniai: 1. Nustatyti galvijų PG-3 ir RS virusų paplitimą Lietuvos galvijų ūkiuose. 2. Palyginti galvijų PG-3 ir RS virusinių infekcijų paplitimą su kitomis Lietuvos galvijų ūkiams aktualiomis virusinėmis ligomis. 3. Nustatyti galvijų paragripo-3 ir respiracinio sincitinio virusų paplitimo geografinius ypatumus. 4. Atlikti PG-3 ir RS virusinių infekcijų laboratorinės diagnostikos metodų palyginamąjį tyrimą. 5. Ištirti krekeninio imuniteto galvijų PG-3 ir RS virusams dinamiką ir trukmę bei jo įtaka veršelių sergamumui. 6. Atlikti vakcinacijos palyginamąjį tyrimą naudojant skirtingus įraumeninį (IM) ir įodinį (ID) vakcinacijos būdus ir bei skirtingas vakcinos dozes. Darbo mokslinė reikšmė ir naujumas: 1. Nustatytas PG-3 ir RS virusų paplitimas ir epidemiologiniai ypatumai Lietuvos galvijų ūkiuose. 2. Atliktas galvijų PG-3, RS, GIR ir GVD virusinių infekcijų paplitimo palyginamasis tyrimas. 3. Atliktas įvairių diagnostinių tyrimų palyginamasis įvertinimas. 4. Nustatytas galvijų PG-3 ir RS virusų serologinis paplitimas Lietuvos apskrityse. 5. Nustatyta pasyvaus krekeninio imuniteto trukmė galvijų PG-3 ir RS virusams bei jo įtaka veršelių sergamumui. 6. Nustatyta, kad ID vakcinacija nuo PG-3 ir RS virusinių infekcijų yra efektyvi... [toliau žr. visą tekstą] / The main objective of the present dissertation: To carry out epidemiological investigations of PI-3 and RS viral infections in the Lithuanian cattle farms, to establish the duration of passive and active immunity and to find out the possibilities of immune response using different routes of vaccination. Goals of the study: 1. To determine the prevalence of bovine PI-3 and RS viruses in the Lithuanian cattle farms. 2. To compare the prevalence of bovine PI-3 and RS viral infections with the prevalence of other cattle–relevant viral diseases at Lithuanian cattle farms. 3. To determine the geographical distribution patterns for PI-3 and RS viruses. 4. To conduct comparative analysis of laboratory diagnostic methods for PI-3 and RS viral infections. 5. To investigate the dynamics and duration of colostral immunity to bovine PI-3 and RS viruses and its influence on the morbidity of calves. 6. To conduct a comparative investigation of different routes of vaccination – intramuscular (IM) and intradermal (ID) – and different doses. Scientific importance and novelty of research: 1. The prevalence and epidemiological peculiarities of PI-3 and RS viruses in the Lithuanian cattle farms were determined. 2. A comparative analysis prevalence of bovine PI-3, RS, IBR and BVD viral infections was conducted. 3. A comparative assessment of various diagnostic investigations was performed. 4. The seroprevalence of bovine PI-3 and RS viral infections in the Lithuanian counties was determined. 5... [to full text]

Cell migration is critical to a wide range of physiological and pathological events and is central to disease progression of B lymphocyte (B cell)-derived leukemia and lymphoma as well as many other types of cancer. It is extensively controlled by phosphoinositide 3-kinase (PI3K), which generates PI(3,4,5)P3 (PIP3) and PI(3,4)P2, lipid messengers that recruit pleckstrin homology (PH)-domain-containing signaling proteins. While PIP3 is known to regulate cell migration, it remains a major unanswered question in the field whether PI(3,4)P2 is also implicated in this cellular function. A series of investigations here on PI(3,4)P2-specific lipid phosphatases and binding proteins in the context of chemotaxing malignant B cells provide the first insights into a previously unappreciated role of PI(3,4)P2 signaling in cell migration. First, I used physiological regulators of PI(3,4)P2, the inositol polyphosphate 4-phosphatase (INPP4) enzymes, as tool to manipulate PI(3,4)P2 levels to determine the function of this lipid second messenger. PI(3,4)P2 depletion by INPP4A or INPP4B relative to phosphatase-dead mutants indicated an essential role of PI(3,4)P2 in mediating both the speed and directionality of chemotaxis. Gene silencing of the authenticated PI(3,4)P2-specific binding protein TAPP2 leads to reduced migration speed and directionality, similar to PI(3,4)P2 depletion. The impaired migration is underlain by alterations in chemokine-induced rearrangement of the actin cytoskeleton, loss of migratory polarity and dysregulation of the leading edge activator Rac. A putative PI(3,4)P2-binding protein, lamellipodin (Lpd), is found to strongly colocalize with PI(3,4)P2 depending on the Lpd PH domain. Lpd knock-down rescue experiments indicated that PI(3,4)P2 controls directionality through Lpd, while Lpd also promotes motility independently of PH domain binding to PI(3,4)P2. The PI(3,4)P2-binding protein kinase Akt/PKB (also binds to PIP3) is found to play a positive role in the B cell context. Here, PI(3,4)P2 depletion does not inhibit phosphorylation of Akt but seemingly reduces its activity. It is likely that PI(3,4)P2 mediates malignant B cell migration in part through promoting Akt activity. Taken together, the thesis work establishes the PI(3,4)P2 pathway as a novel branch of the PI3K signaling network controlling cell migration and suggests that PI(3,4)P2 may integrate diverse downstream migratory pathways to impact on cell migration.

There are currently three known crystal packing motifs of boronsubphthalocyanine derivatives. Each motif is associated with a particular class of BsubPc derivatives, and none are ideal for organic electronic applications according to the criteria we defined for evaluation: having a continuous pathway for charge-carrier conduction in the solid-state, resistance to hydrolysis, good electrochemical and optical properties, and possession of a robust crystal form. In this thesis, we present five methods for altering the crystal packing structure of phenoxy-BsubPc derivatives in order to meet the above four criteria. We find that neither addition of steric bulk to the axial derivative nor changing the symmetry of the compounds is sufficient for creating a new crystal packing motif. We do find that reducing the symmetry of the axial group does increase the solubility greatly, however. We identify a new motif for BsubPc crystals that occurs when the intermolecular interactions between the axial phenoxy segment and the BsubPc ligand are increased. We present two methods for achieving this new motif, one is through addition of a π-Br interaction and the other is through creation of a strong π-acid/ π-base stacking by making the axial phenoxy more π-electron rich. Unfortunately, the p-bromophenoxy-BsubPc forms this new motif as a kinetic product, isolation of which is unreliable. Attaching a naphthol fragment axially to the BsubPc creates a stable version of this new motif. We also synthesized a new class of BsubPc pseudohalides based on sulfonate derivatives. Of the derivatives in this new class, we found that mesylate-BsubPc forms into a crystal packing structure that possesses a one-dimensional pathway for charge carrier mobility, but is still resistant to hydrolysis under the conditions tested. Overall, we show four compounds that meet the criteria for further study as organic electronic materials: p-methoxyphenoxy-BsubPc, α-naphthoxy-BsubPc, β-naphthoxy-BsubPc, and mesylate-BsubPc.

There are currently three known crystal packing motifs of boronsubphthalocyanine derivatives. Each motif is associated with a particular class of BsubPc derivatives, and none are ideal for organic electronic applications according to the criteria we defined for evaluation: having a continuous pathway for charge-carrier conduction in the solid-state, resistance to hydrolysis, good electrochemical and optical properties, and possession of a robust crystal form. In this thesis, we present five methods for altering the crystal packing structure of phenoxy-BsubPc derivatives in order to meet the above four criteria. We find that neither addition of steric bulk to the axial derivative nor changing the symmetry of the compounds is sufficient for creating a new crystal packing motif. We do find that reducing the symmetry of the axial group does increase the solubility greatly, however. We identify a new motif for BsubPc crystals that occurs when the intermolecular interactions between the axial phenoxy segment and the BsubPc ligand are increased. We present two methods for achieving this new motif, one is through addition of a π-Br interaction and the other is through creation of a strong π-acid/ π-base stacking by making the axial phenoxy more π-electron rich. Unfortunately, the p-bromophenoxy-BsubPc forms this new motif as a kinetic product, isolation of which is unreliable. Attaching a naphthol fragment axially to the BsubPc creates a stable version of this new motif. We also synthesized a new class of BsubPc pseudohalides based on sulfonate derivatives. Of the derivatives in this new class, we found that mesylate-BsubPc forms into a crystal packing structure that possesses a one-dimensional pathway for charge carrier mobility, but is still resistant to hydrolysis under the conditions tested. Overall, we show four compounds that meet the criteria for further study as organic electronic materials: p-methoxyphenoxy-BsubPc, α-naphthoxy-BsubPc, β-naphthoxy-BsubPc, and mesylate-BsubPc.

The following thesis focuses on two areas of chemistry, pi-pi interactions and radical cation dimers. Approximations to the exact solution to the Schrodinger equation are investigated for these types of chemical systems with a variety of theoretical methods. The first chapter provides an introduction to the various quatum mechanical methods used in this research. The second chapter focuses specifically on pi-pi interaction. In this chapter, high quality quantum mechanical methods are used to examine how substituents tune pi-pi interactions between monosubstituted benzene dimers in parallel-displaced geometries. In addition, the role of dispersion and coulombic interactions in these systems is investigated to determine the nature of the substituent effect. In the third chapter radical cation dimers are investigated. Benchmark results with full configuration interaction (FCI) and equation-of-motion coupled-cluster for ionized systems (EOM-IP-CCSD) are presented for prototypical charge transfer species. Conclusions regarding chapters 2 and 3 are presented in the final chapter. This work may form the basis for improved approaches to rational drug design, organic optical materials, and molecular electronics.

Zugl.: Chemnitz, Techn. Univ., Diss., 2006

Heidelberg, Univ., Diss., 2007. / Online publiziert: 2008.

Universiẗat, Diss., 2002--Bielefeld.