Joint Exercise of Parental Rights in the Context of Divorce

Joint exercise of parental rights is an adequate form of parental care after divorce if the parents are able to overcome mutual animosity, and resolve conflicts, that may result in the complete dissolution of the family unit. Joint custody eliminates the negative effects of the sole exercise of parental rights since former spouses still have equal legal status after divorce so that they are jointly responsible for raising a child. In joint custody, parents jointly exercise all rights and responsibilities of parenting and make agreements, whereas the physical custody of the child in most cases belongs to one parent, though there may be an option of the child’s alternate residence with both parents, in which case both parents alternately have the custody of the child.The concept of joint exercise of parental rights is based on the idea of equally important role of both parents in the proper physical and mental development of the child and on the principle of parents’ equality in relation to the child. In addition, joint custody endeavors to preserve the relationship between the child and the parent with whom it does not live. Therefore, the positive effects of joint custody reflect on all participants in the relation of parental rights. In the European legal space joint custody after divorce is exceptionally popular. However, since it was legalized in 2005, this form of parenting by divorced parents has not been sufficiently established in practice in the Republic of Serbia. Still, with the further insight into the advantages of the joint custody, it is reasonable to expect that parents will increasingly opt for this form of care. In addition, given the evolution of the model of joint care in comparative law, it is reasonable to conclude that in due course the presumption of joint exercise of parental rights after divorce will find its place in the Serbian legal system.Key words: joint exercise of parental rights, divorce, parents, children, Serbian law, comparative law

Using metadata for content indexing within an OER network

This paper outlines the ICT solution for a metadata portal indexing open educational resources within a network of institutions. The network is aimed at blending academic and entrepreneurial knowledge,by enabling higher education institutions to publish various academic learning resources e.g. video lectures, course planning materials, or thematic content, whereasenterprises can present different forms of expert knowledge, such as case studies, expert presentations on specific topics, demonstrations of software implementation in practice and the like. As these resources need to bediscoverable, accessible and shared by potential learners across the learning environment, it is very important that they are well described and tagged in a standard way in machine readable form by metadata. Only then can they be successfully used and reused, especially when a large amount of these resources is reached, which makes it hard for the user to locate efficiently those of interest. The metadata set adopted in our approach relies on two standards: Dublin Core and Learning Object Metadata. The aim of metadata and the corresponding metadata portal described in this paper is to provide structured access to information on open educational resources within the network

Signalling reactions of PI3Kgamma in T cells

Phosphoinositide 3-kinases (PI3Ks) are a family of lipid kinases involved in the regulation of diverse important cellular functions. The members of PI3K class I exhibit dual enzymatic specificity both as lipid kinases and protein serine kinases, and they are known to be indispensable for the development and proper functions of T lymphocytes. The involvement of PI3Ks in the activation of T cells is clearly demonstrated and so far mostly related to the PI3K class IA enzymes (alpha, beta and delta isoforms), but it was found that PI3Kgamma, the single member of class IB PI3K, is also involved in the regulation of activation-induced proliferation and cytokine production of T cells. How PI3Kgamma participates in this mechanism is largely elusive. Earlier reports proved that PI3Kgamma KO mice have a reduced number and an impaired differentiation of thymocytes, as well as a reduced number of CD4 T cells in spleen. We confirmed this earlier findings regarding disrupted differentiation of PI3Kgamma KO thymocytes, but in addition results presented here showed that this gene disruption had an even stronger impact on the mouse phenotype, significantly reducing the number of T cells in spleen and lymph nodes and effecting both major subpopulations of mature T cells (CD4 and CD8 cells). In published studies PI3Kgamma KO T cells showed reduced proliferation upon T cell receptor (TCR) stimulation. Costimulation with specific anti-CD28 antibody or activation with Ionomycin and phorbol ester is able to rescue this proliferation, in contrast to subsequent interleukin-2 (IL-2) and interferon-gamma production. In our experiments IL-2 costimulation of TCR-activated PI3Kgamma KO T cells was also sufficient to rescue this impaired proliferation, which clearly implicated that the lack of cytokines may be the major cause of their functional defect. In order to elucidate how PI3Kgamma couples the activation of TCR and IL-2 production in Jurkat cells, we used the PI3Kgamma specific inhibitor AS041164. In our experimental settings AS041164 did not exhibit any detectable cytotoxicity within the applied concentration range. Furthermore, this substance had no significant influence on overall PI3K activity in Jurkat cells proving its selectivity and specificity in our model. The results obtained by applying AS041164 on Jurkat cells implicated that PI3Kgamma may not be involved in the signalling events in the proximity of activated TCR, and that PI3Kgamma is dispensable for certain aspects of T cell activation, such as CD69 expression. Nevertheless, treatment with AS041164 clearly and reproducibly reduced IL-2 production of activated Jurkat cells in dose-dependent manner. Jurkat cells have constant high level of PIP3, the major product of PI3K lipid-kinase activity; therefore it is most likely that this effect was caused by a lack of PI3Kgamma protein kinase-activity. PI3Kgamma specifically interactions with several isoforms of protein kinase C (PKC) in Jurkat cells were also proved in this thesis. These interactions seem to be important for the proper function of interacting PKC isoforms upon T cell activation and for the subsequent IL-2 production. Finally, our results showed that PI3Kgamma may be involved in the control of IL-2 production on several levels from transcription to secretion, and one of these levels is apparently PKC-related. In conclusion, results from this thesis clearly demonstrate that PI3Kgamma is an important modulator of thymocyte proliferation and differentiation. Moreover, PI3Kgamma is necessary for the TCR-induced IL-2 production, a process known to be crucial for the normal proliferation of T cells after antigen receptor activation. PI3Kgamma interacts with several PKC isoforms and modulate their activity upon TCR engagement, which is necessary for the IL-2 production. Described interactions depend on overall PI3K lipid-kinase activity as well as PI3Kgamma protein-kinase activity. This various modes of protein-protein interactions and kinase activity clearly show the PI3Kgamma is a multifunctional enzyme important for proper development and function of lymphocytes

Regulation of FBP1 expression and changes in glucose metabolism are crucial for an appropriate response to DNA damage and aging in S.cerevisiae

Exposure of living organisms to smaller amounts of toxic agents and other adverse effects may be more common in natural environments than direct impact of highly cytotoxic doses of the same agents. Occurring over various time spans or as the consequence of repeated exposures, the accumulation of mutations may be as critical for the organism as the immediate cytotoxic effect. Therefore, cellular response to the treatment with DNA-damaging substances at low concentrations which are genotoxic but do not have a strong cytotoxic effect are of special interest. Investigating the transcriptional response of S.cereveisiae to low doses of the alkylating agent methylmethane sulfonate (MMS) we observed that cellular sensitivity to MMS directly depends on their ability to immediately induce the basic, stereotypical stress response program called ESR. Modulation of basic metabolic pathways and induction of diauxic shift are factors that directly contributed to the increased resistance of the FF18984 strain to MMS. Metabolic adaptation and pre-induction of ESR resulting from nutrient deprivation helped this strain to cope better with the toxic effect of genotoxic agents applied later such as MMS. Our results showed that the major stimulus that triggers the adaptive response and the induction of ESR genes upon MMS treatment is an alteration in glucose utilization. These results point to an important correlation between metabolic pathways and the ability of living organisms to cope with adverse environmental conditions. Moreover, the induction of ESR seemed to be the most important prerequisite for a proper and fast cellular response to DNA damage. Expression of the key enzyme of gluconeogenesis fructose-1,6-bisphosphatase (FBP1) was clearly up-regulated by MMS in glucose-rich medium. Interestingly, deletion of FBP1 led to reduced sensitivity to MMS, but not to other DNA damaging agents such as 4-nitroquinoline (4-NQO) or phleomycin. The reduced sensitivity of the fbp1 mutant was the result of better recovery of this mutant after a long-term treatment with MMS. Reintroduction of FBP1 in the knockout strain restored the wild-type phenotype while overexpression increased MMS-sensitivity of wild-type. The connection between Fbp1p and one of the most important DNA damage signalling cascade that starts with the Mec1/Tel1 damage sensors was investigated with the RNR2-GFP reporter assay. These experiments revealed that the deletion of FBP1 had no effect on induction through the RNR2 promoter while overexpression of FBP1 significantly increased the activity of the RNR2 promoter. These results indicated that the increased intracellular level of Fbp1p after DNA damage caused by MMS probably acts as a signal that mediates cellular response to this toxic agent. Deletion of FBP1 reduced the production of reactive oxygen species (ROS) in response to MMS and in untreated aged cells. The mutant cells showed delayed production of ROS in the first fifteen days in aging culture what resulted in better viability in full medium. In minimal medium the lack of Fbp1p was no advantage for cellular survival. In these conditions aged fbp1 mutants survived even less and accumulated similar levels of ROS. Elevated amounts of Fbp1p shortened life-span, but did not have any influence on ROS accumulation. These results showed that Fbp1p is an important factor that modulates ROS production in response to MMS treatment and aging. However, in media with limited nutrients Fbp1p is a critical factor for cellular survival and its lack is rather a disadvantage. Based on the above observations, we concluded that FBP1 influences the connection between DNA damage, aging and oxidative stress either through direct signalling or an intricate adaptation in energy metabolism. In consequence, the tight regulation of FBP1 expression and age-associated changes in glucose metabolism are not only crucial for the control of gluconeogenesis but also for an appropriate response to aging and DNA damage

Key global challenges for churches concerning the protection of human dignity and human rights in our time : perspectives from the thematic group on Human Rights of the conference of European churches

Paper presented at the Conference on Christian Perspectives on Human Dignity and Humans Rights held in Wuppertal (Germany) online from 9–12 April 202

Functional microdomains in G-protein-coupled receptors: the conserved arginine-cage motif in the gonadotropin-releasing hormone receptor

An Arg present in the third transmembrane domain of all rhodopsin-like G-protein-coupled receptors is required for efficient signal transduction. Mutation of this Arg in the gonadotropin-releasing hormone receptor to Gln, His, or Lys abolished or severely impaired agonist-stimulated inositol phosphate generation, consistent with Arg having a role in receptor activation. To investigate the contribution of the surrounding structural domain in the actions of the conserved Arg, an integrated microdomain modeling and mutagenesis approach has been utilized. Two conserved residues that constrain the Arg side chain to a limited number of conformations have been identified. In the inactive wild-type receptor, the Arg side chain is proposed to form an ionic interaction with Asp3.49(138). Experimental results for the Asp3. 49(138) --> Asn mutant receptor show a modestly enhanced receptor efficiency, consistent with the hypothesis that weakening the Asp3. 49(138)-Arg3.50(139) interaction by protonation of the Asp or by the mutation to Asn favors activation. With activation, the Asp3. 49(138)-Arg3.50(139) ionic bond would break, and the unrestrained Arg would be prevented from orienting itself toward the water phase by a steric clash with Ile3.54(143). The mutation Ile3.54(143) --> Ala, which eliminates this clash in simulations, causes a marked reduction in measured receptor signaling efficiency, implying that solvation of Arg3.50(139) prevents it from functioning in the activation of the receptor. These data are consistent with residues Asp3.49(138) and Ile3.54(143) forming a structural motif, which helps position Arg in its appropriate inactive and active receptor conformations

Computer Controlled Automated Assay for Comprehensive Studies of Enzyme Kinetic Parameters

Stability and biological activity of proteins is highly dependent on their physicochemical environment. The development of realistic models of biological systems necessitates quantitative information on the response to changes of external conditions like pH, salinity and concentrations of substrates and allosteric modulators. Changes in just a few variable parameters rapidly lead to large numbers of experimental conditions, which go beyond the experimental capacity of most research groups. We implemented a computer-aided experimenting framework (“robot lab assistant”) that allows us to parameterize abstract, human-readable descriptions of micro-plate based experiments with variable parameters and execute them on a conventional 8 channel liquid handling robot fitted with a sensitive plate reader. A set of newly developed R-packages translates the instructions into machine commands, executes them, collects the data and processes it without user-interaction. By combining script-driven experimental planning, execution and data-analysis, our system can react to experimental outcomes autonomously, allowing outcome-based iterative experimental strategies. The framework was applied in a response-surface model based iterative optimization of buffer conditions and investigation of substrate, allosteric effector, pH and salt dependent activity profiles of pyruvate kinase (PYK). A diprotic model of enzyme kinetics was used to model the combined effects of changing pH and substrate concentrations. The 8 parameters of the model could be estimated from a single two-hour experiment using nonlinear least-squares regression. The model with the estimated parameters successfully predicted pH and PEP dependence of initial reaction rates, while the PEP concentration dependent shift of optimal pH could only be reproduced with a set of manually tweaked parameters. Differences between model-predictions and experimental observations at low pH suggest additional protonation-sites at the enzyme or substrates critical for enzymatic activity. The developed framework is a powerful tool to investigate enzyme reaction specifics and explore biological system behaviour in a wide range of experimental conditions

Promoter Hypermethylation Mediated Downregulation of FBP1 in Human Hepatocellular Carcinoma and Colon Cancer

FBP1, fructose-1,6-bisphosphatase-1, a gluconeogenesis regulatory enzyme, catalyzes the hydrolysis of fructose 1,6-bisphosphate to fructose 6-phosphate and inorganic phosphate. The mechanism that it functions to antagonize glycolysis and was epigenetically inactivated through NF-kappaB pathway in gastric cancer has been reported. However, its role in the liver carcinogenesis still remains unknown. Here, we investigated the expression and DNA methylation of FBP1 in primary HCC and colon tumor. FBP1 was lowly expressed in 80% (8/10) human hepatocellular carcinoma, 66.7% (6/9) liver cancer cell lines and 100% (6/6) colon cancer cell lines, but was higher in paired adjacent non-tumor tissues and immortalized normal cell lines, which was well correlated with its promoter methylation status. Methylation was further detected in primary HCCs, gastric and colon tumor tissues, but none or occasionally in paired adjacent non-tumor tissues. Detailed methylation analysis of 29 CpG sites at a 327-bp promoter region by bisulfite genomic sequencing confirmed its methylation. FBP1 silencing could be reversed by chemical demethylation treatment with 5-aza-2′-deoxycytidine (Aza), indicating direct epigenetic silencing. Restoring FBP1 expression in low expressed cells significantly inhibited cell growth and colony formation ability through the induction of G2-M phase cell cycle arrest. Moreover, the observed effects coincided with an increase in reactive oxygen species (ROS) generation. In summary, epigenetic inactivation of FBP1 is also common in human liver and colon cancer. FBP1 appears to be a functional tumor suppressor involved in the liver and colon carcinogenesis

A Crucial Role for Primary Cilia in Cortical Morphogenesis

Primary cilia are important sites of signal transduction involved in a wide range of developmental and postnatal functions. Proteolytic processing of the transcription factor Gli3, for example, occurs in primary cilia, and defects in intraflagellar transport (IFT), which is crucial for the maintenance of primary cilia, can lead to severe developmental defects and diseases. Here we report an essential role of primary cilia in forebrain development. Uncovered by N-ethyl-N-nitrosourea-mutagenesis, cobblestone is a hypomorphic allele of the IFT gene Ift88, in which Ift88 mRNA and protein levels are reduced by 70-80%. cobblestone mutants are distinguished by subpial heterotopias in the forebrain. Mutants show both severe defects in the formation of dorsomedial telencephalic structures, such as the choroid plexus, cortical hem and hippocampus, and also a relaxation of both dorsal-ventral and rostral-caudal compartmental boundaries. These defects phenocopy many of the abnormalities seen in the Gli3 mutant forebrain, and we show that Gli3 proteolytic processing is reduced, leading to an accumulation of the full-length activator isoform. In addition, we observe an upregulation of canonical Wnt signaling in the neocortex and in the caudal forebrain. Interestingly, the ultrastructure and morphology of ventricular cilia in the cobblestone mutants remains intact. Together, these results indicate a critical role for ciliary function in the developing forebrain

Vacuole inheritance regulates cell size and branching frequency of Candida albicans hyphae

Hyphal growth of Candida albicans is characterized by asymmetric cell divisions in which the subapical mother cell inherits most of the vacuolar space and becomes cell cycle arrested in G1, while the apical daughter cell acquires most of the cell cytoplasm and progresses through G1 into the next mitotic cell cycle. Consequently, branch formation in hyphal compartments is delayed until sufficient cytoplasm is synthesized to execute the G1 ‘START’ function. To test the hypothesis that this mode of vacuole inheritance determines cell cycle progression and therefore the branching of hyphae, eight tetracycline-regulated conditional mutants were constructed that were affected at different stages of the vacuole inheritance pathway. Under repressing conditions, vac7, vac8 and fab1 mutants generated mycelial compartments with more symmetrically distributed vacuoles and increased branching frequencies. Repression of VAC1, VAM2 and VAM3 resulted in sparsely branched hyphae, with large vacuoles and enlarged hyphal compartments. Therefore, during hyphal growth of C. albicans the cell cycle, growth and branch formation can be uncoupled, resulting in the investment of cytoplasm to support hyphal extension at the expense of hyphal branching