Pseudo-Riemannian Jacobi-Videv Manifolds

We exhibit several families of Jacobi-Videv pseudo-Riemannian manifolds which are not Einstein. We also exhibit Jacobi-Videv algebraic curvature tensors where the Ricci operator defines an almost complex structure

Improving Safety at Sea Through Compliance with International Maritime Safety Codes

There is a number of international instruments that contribute to the improvement and advancement of safety at sea. The primary task of all international instruments is to make sea navigation less dangerous and to reduce, to the maximum extent possible, the risks associated with maritime navigation, and hence the occurrence of maritime accidents and marine pollution. In addition to international conventions as basic international instruments, codes adopted by various international organizations are of particular importance for improving the safety of navigation. The IMO, as the main organization responsible for improving maritime safety, certainly occupies a special place. Since its inception, the IMO has convened many international conferences and developed many regulations, recommendations and codes of practice concerning the carriage of dangerous cargoes by sea. Thirty conventions and protocols, as well as a number of codes and recommendations concerning maritime safety, the prevention of marine pollution and other related matters have been adopted by the IMO. In this paper we have tried to point out the most important international codes the observance of which is imperative for improving safety at sea. Attention is paid to the role of a number of international organizations in the safety of navigation, with special emphasis on the IMO

THE INFLUENCE OF NATIONAL CULTURE ON CERTAIN TYPES OF ORGANIZATIONAL CULTURE

National culture, among other factors, largely determines organizational behavior. The paper relates to influence of national culture on certain types of organizational behavior such as: motivation, organizational changes and communication process. Introductory section emphasizes the importance of  proper understanding of the relationship between national and organizational culture, especially emphasizing the role of cultural factors that largely determine organizational behavior in modern conditions. The author first provides an overview of different perspectives in defining national culture. To explain the influence of national culture on certain forms of organizational behavior, the author uses Hofstede dimensions of national cultures. In that context, the author analyzes the influence of national culture on motivation and organizational changes. Various forms of communication that represent the consequence of different cultural influences are anylyzed further in the article. Final section of the paper provides conclusions about influence of national culture on motivation, organizational changes and communication process. Key words:  national culture, organization, management, organizational behavior

The metacognitions about self-critical rumination questionnaire

BACKGROUND: Self-criticism refers to a series of persistent and negative self-judgements, often involuntary, that an individual makes about themselves. Recent research has explored the possibility that self-criticism can lead to a more perseverative style of thinking called self-critical rumination. There is evidence that self-critical rumination may be a separate construct from other forms of rumination, such as depressive rumination and post-event processing. Research has indicated that metacognitions, beliefs that individuals have about their internal experiences and how to control them, may play a role in self-critical rumination. The aim of our work was to develop a measure to assess metacognitions related to self-critical rumination. METHOD: In Study 1, a community sample of 178 participants completed the newly developed Metacognitions about Self-Critical Rumination Questionnaire (MSCRQ) and results were subjected to a Principal Components Analysis. In Study 2, a community sample of 247 participants completed a battery of questionnaires including the MSCRQ. A Confirmatory Factors Analysis was performed on the MSCRQ and validity was ascertained by correlating with other measures. RESULTS: In Study 1, a 15-item two-factor structure was identified. A 10-item two-factor structure was confirmed in Study 2. Results also indicated that the MSCRQ has acceptable levels of reliability, and good concurrent and incremental validity. CONCLUSIONS: The MSCRQ appears to be a reliable and valid measure of metacognitions about self-critical rumination whilst the MCQ-30 is a better predictor of general emotional distress

Retinoic acid-induced SoX3 gene expression in NT2/D1 cells is RXR homodimer-independent

Sox3/SOX3 gen je uključen u kontrolu razvića nervnog sistema. Naša prethodna istraživanja su pokazala da tokom neuralne indukcije NT2/D1 ćelija retinoičnom kiselinom (RK) dolazi do promene ekspresije humanog SOX3 gena. Takođe, pokazali smo da su RXR retinoidni receptori glavni posrednici efekta RK na SOX3 ekspresiju, dok su članovi RAR familije receptora isključeni kao njihovi heterodimerni partneri u ovom signalnom putu. Rezultati predstavljeni u ovom radu ukazuju da je aktivacija SOX3 gena retinoičnom kiselinom nezavisna od RXR homodimera. Ova izučavanja ekspresije SOX3 gena su značajna za buduća istraživanja uticaja koji ovaj gen ima na različite aspekte normalnog i patološkog razvića.The Sox3/SOX3 gene is implicated in the control of nervous system development. We previously demon­strated modulation of human SOX3 gene expression during neural induction of NT2/D1 cells by retinoic acid (RA). Also, we accurately verified RXR retinoid receptors as major mediators of the effect of RA on SOX3 expression, and excluded RARs as its heterodimeric partners in RA-SOX3 signaling. Here we present evidence that activation of the SOX3 gene by RA is not RXR homodimer-dependent. The described line of SOX3 gene expression studies is valuable for future investigation of the impact that this gene has multiple aspects of normal and pathological development

Gene expression analysis by non-radioactive RNA-RNA in situ hybridization techniques

RNK-RNK in situ hibridizacija je pogodna metoda za izučavanje specifične ekspresije gena u tkivima i ćelijama, kojom je omogućena vizualizacija obeležene antisens RNK probe hibridizovane za specifičnu iRNK. U ovom radu prikazano je detektovanje ekspresije SOX gena u tumorskim ćelijskim linijama primenom neradioaktivne RNK-RNK in situ hibridizacije koristeći RNK probe obeležene biotinom ili digoksigeninom. Koristeći ovaj pristup potvrđeni su rezultati dobijeni Northern blot analizom, tj. pokazano je prisustvo SOX2 iRNK u NT2/D1 i SOX14 iRNK u HepG2 ćelijama. Cilj ovog rada bio je uspostavljanje RNK-RNK in situ hibridizacije na in vitro kultivisanim ćelijama da bi metodu primenili pri proučavanju ekspresije SOX gena u različitim normalnim i tumorskim tkivima.RNA-RNA in situ hybridization is a reliable method for studying tissue and cell specific gene expression, which enables visualization of labeled antisense RNA probe hybridized to specific mRNA. In this study we employed non-radioactive RNA-RNA in situ hybridization using biotin- or digoxigenin-labeled RNA probes in order to detect SOX gene expression in carcinoma cell lines. By this approach we confirmed results obtained by Northern blot analysis, where the presence of SOX2 mRNA in NT2/D1 and SOX14 mRNA in HepG2 cells has been established. Our aim was to set up RNA-RNA in situ hybridization method in in vitro cultured cells in order to perform further analyses of SOX gene expression on various normal and cancer tissues