99 research outputs found

    Efficient Portfolio Selection and Its Applications to Decision Making

    Get PDF
    Abstract—Dynamic nature of investment return requires the application of the appropriate methodology, especially regarding enhanced volatility induced by frequent extreme events occurrence. The subject of the research is to analyze the possibility of efficient portfolio selection on the transitional financial market of the Republic of Serbia.  The main objective is to gather empirical evidence about the investment portfolio performance with special attention to the decision making process. The methodology in the research implies the usage of the appropriate portfolio optimization methods. The research results stress the significance of efficient portfolio selection in contemporary business conditions. It can be concluded that it is necessary to examine the volatility of the portfolio assets and thus enabling the efficient portfolio selection, which is especially challenging on transitional markets

    Vrste plesni na kukuruznom klipu uskladištenom u koševima na teritoriji opština Vrnjačka Banja i Kruševac

    Get PDF
    Corn cob owned by individual producers is stored on multiple ways: in barns, attics, sheds etc. If corn cob is not dried properly when stord in barns, it represents ideal foundation for field and storage molds.For our examinations we used corn from 20 barns originating from ten plain and mountain villages in Vrnjacka Banja municipality. Mold isolation was performed on saburo ager on temperature of 27oC. Most commonly isolated sorts of mold were: Penicillium sp., Aspergillus ustus, Alternaria tenuis, Yeast, Mucor mucedo, Fusarium roseum, Aspergillus candidus, Trichoderma viride and Aspergillus flavus. Our results show that dominant role was frequently represented by field molds – Alternaria and Fusarium, most common of storage molds were molds from the genus Aspergillus and Penicillium, and most common progressive decay molds were Mucor and Rhisopos. Infection of grain was by rule 100% with rare exeptions.Kukuruzni klip u vlasništvu individualnih proizvođača skladišti se na više načina: u koševima, tavanima, šupama i dr. Ukoliko se kukuruzni klip, nedovoljno osušen, skladišti u koševe on predstavlja idealnu podlogu za razvoj poljskih i skladišnih plesni. Za ispitivanja smo koristili kukuruz iz 20 koševa koji su poreklom iz 10 sela ravničarskog i planinskog predela sa područja opštine Vrnjačka Banja. Izolaciju plesni vršili smo na Saburo agaru na temperaturi od 27°C. Najčešće su izolovane sledeće vrste plesni: Penicillium sp., Aspergillus ustus, Alternaria tenuis, Kvasnice, Mucor mucedo, Fusarium roseum, Aspergillus candidus, Trichoderma viride i Aspergillus flavus. Naši rezultati pokazuju da su dominantnu ulogu u frekvenciji predstavljale plesni s polja- Alternaria i Fusarium, od plesni uskladištenja najučestalije su bile plesni iz roda Aspergillus i Penicillium, a od plesni uznapredovanog kvarenja Mucor i Rhisopus. Infekcija zrna je bila po pravilu 100% sa retkim odstupanjima

    RNAi-Mediated c-Rel Silencing Leads to Apoptosis of B Cell Tumor Cells and Suppresses Antigenic Immune Response In Vivo

    Get PDF
    c-Rel is a member of the Rel/NF-κB transcription factor family and is predominantly expressed in lymphoid and myeloid cells, playing a critical role in lymphocyte proliferation and survival. Persistent activation of the c-Rel signal transduction pathway is associated with allergies, inflammation, autoimmune diseases, and a variety of human malignancies. To explore the potential of targeting c-Rel as a therapeutic agent for these disorders, we designed a small interfering RNA (siRNA) to silence c-Rel expression in vitro and in vivo. C-Rel-siRNA expression via a retroviral vector in a B cell tumor cell line leads to growth arrest and apoptosis of the tumor cells. Silencing c-Rel in primary B cells in vitro compromises their proliferative and survival response to CD40 activation signals, similar to the impaired response of c-Rel knockout B cells. Most important, in vivo silencing of c-Rel results in significant impairment in T cell-mediated immune responses to antigenic stimulation. Our study thus validates the efficacy of c-Rel-siRNA, and suggests the development of siRNA-based therapy, as well as small molecular inhibitors for the treatment of B cell tumors as well as autoimmune diseases

    c-Rel Deficiency Increases Caspase-4 Expression and Leads to ER Stress and Necrosis in EBV-Transformed Cells

    Get PDF
    LMP1-mediated activation of nuclear factor of kappaB (NF-κB) is critical for the ligand independent proliferation and cell survival of in vitro EBV-transformed lymphoblastoid cell lines (LCLs). Previous experiments revealed that a majority of LMP1-dependent responses are regulated by NF-κB. However, the extent that individual NF-κB family members are required for these responses, in particular, c-Rel, whose expression is restricted to mature hematopoietic cells, remains unclear. Here we report that low c-Rel expression in LCLs derived from a patient with hyper-IgM syndrome (Pt1), resulted in defects in proliferation and cell survival. In contrast to studies that associated loss of NF-κB with increased apoptosis, Pt1 LCLs failed to initiate apoptosis and alternatively underwent autophagy and necrotic cell death. Whereas the proliferation defect appeared linked to a c-Rel-associated decrease in c-myc expression, identified pro-survival and pro-apoptotic targets were expressed at or near control levels consistent with the absence of apoptosis. Ultrastructural examination of Pt1 LCLs revealed a high level of cellular and ER stress that was further supported by gene expression profiling showing the upregulation of several genes involved in stress and inflammation. Apoptosis-independent cell death was accompanied by increased expression of the inflammatory marker, caspase-4. Using gene overexpression and siRNA knockdown we demonstrated that levels of c-Rel directly modulated expression of caspase-4 as well as other ER stress genes. Overall, these findings reveal the importance of c-Rel in maintaining LCL viability and that decreased expression results in ER stress and a default response leading to necrotic cell death

    The role of RAS oncogene in survival of patients with lung cancer: a systematic review of the literature with meta-analysis

    Get PDF
    The proto-oncogene RAS, coding for a 21 kDa protein (p21), is mutated in 20% of lung cancer. However, the literature remains controversial on its prognostic significance for survival in lung cancer. We performed a systematic review of the literature with meta-analysis to assess its possible prognostic value on survival. Published studies on lung cancer assessing prognostic value of RAS mutation or p21 overexpression on survival were identified by an electronic search. After a methodological assessment, we estimated individual hazard ratios (HR) estimating RAS protein alteration or RAS mutation effect on survival and combined them using meta-analytic methods. In total, 53 studies were found eligible, with 10 concerning the same cohorts of patients. Among the 43 remaining studies, the revelation method was immunohistochemistry (IHC) in nine and polymerase chain reaction (PCR) in 34. Results in terms of survival were significantly pejorative, significantly favourable, not significant and not conclusive in 9, 1, 31, 2, respectively. In total, 29 studies were evaluable for meta-analysis but we aggregated only the 28 dealing with non-small-cell lung cancer (NSCLC) and not the only one dealing with small-cell-lung cancer (SCLC). The quality scores were not statistically significantly different between studies with or without significant results in terms of survival, allowing us to perform a quantitative aggregation. The combined HR was 1.35 (95% CI: 1.16–1.56), showing a worse survival for NSCLC with KRAS2 mutations or p21 overexpression and, particularly, in adenocarcinomas (ADC) (HR 1.59; 95% CI 1.26–2.02) and in studies using PCR (HR 1.40; 95% CI 1.18–1.65) but not in studies using IHC (HR 1.08; 95% CI 0.86–1.34). RAS appears to be a pejorative prognostic factor in terms of survival in NSCLC globally, in ADC and when it is studied by PCR

    Cell Type–Specific Thalamic Innervation in a Column of Rat Vibrissal Cortex

    Get PDF
    This is the concluding article in a series of 3 studies that investigate the anatomical determinants of thalamocortical (TC) input to excitatory neurons in a cortical column of rat primary somatosensory cortex (S1). We used viral synaptophysin-enhanced green fluorescent protein expression in thalamic neurons and reconstructions of biocytin-labeled cortical neurons in TC slices to quantify the number and distribution of boutons from the ventral posterior medial (VPM) and posteromedial (POm) nuclei potentially innervating dendritic arbors of excitatory neurons located in layers (L)2–6 of a cortical column in rat somatosensory cortex. We found that 1) all types of excitatory neurons potentially receive substantial TC input (90–580 boutons per neuron); 2) pyramidal neurons in L3–L6 receive dual TC input from both VPM and POm that is potentially of equal magnitude for thick-tufted L5 pyramidal neurons (ca. 300 boutons each from VPM and POm); 3) L3, L4, and L5 pyramidal neurons have multiple (2–4) subcellular TC innervation domains that match the dendritic compartments of pyramidal cells; and 4) a subtype of thick-tufted L5 pyramidal neurons has an additional VPM innervation domain in L4. The multiple subcellular TC innervation domains of L5 pyramidal neurons may partly explain their specific action potential patterns observed in vivo. We conclude that the substantial potential TC innervation of all excitatory neuron types in a cortical column constitutes an anatomical basis for the initial near-simultaneous representation of a sensory stimulus in different neuron types

    Improved functionalization of oleic acid-coated iron oxide nanoparticles for biomedical applications

    Get PDF
    Superparamagnetic iron oxide nanoparticles can providemultiple benefits for biomedical applications in aqueous environments such asmagnetic separation or magnetic resonance imaging. To increase the colloidal stability and allow subsequent reactions, the introduction of hydrophilic functional groups onto the particles’ surface is essential. During this process, the original coating is exchanged by preferably covalently bonded ligands such as trialkoxysilanes. The duration of the silane exchange reaction, which commonly takes more than 24 h, is an important drawback for this approach. In this paper, we present a novel method, which introduces ultrasonication as an energy source to dramatically accelerate this process, resulting in high-quality waterdispersible nanoparticles around 10 nmin size. To prove the generic character, different functional groups were introduced on the surface including polyethylene glycol chains, carboxylic acid, amine, and thiol groups. Their colloidal stability in various aqueous buffer solutions as well as human plasma and serum was investigated to allow implementation in biomedical and sensing applications.status: publishe
    corecore