Heterogeneity and evolution of expectations in a model of currency crisis

A simple model of a portfolio allocation between mature and emerging markets is specified. The representative-agent, rational expectations version of the model has an unlimited number of equilibria, providing no reason to expect that heterogeneous agents would all coordinate on one or another equilibrium. Therefore, the model is simulated with heterogeneous expectations based on ex post returns, imitation, and experimentation. Solutions produce periodic crises, as periods of excessive optimism plant the seed for their reversal, despite the fact that interest rates fall before crises, instead of rising.     

Fabrication, in vitro degradation and the release behaviours of poly(DL-lactide-co-glycolide) nanospheres containing ascorbic acid

Ascorbic acid (vitamin C) is essential for preserving optimal health and is used by the body for many purposes. The problem is that ascorbic acid easily decomposes into biologically inactive compounds making its use very limited in the field of pharmaceuticals, dermatological and cosmetics. By encapsulating the ascorbic acid into a polymer matrix it is assumed that its chemical instability can be overcome as well as higher, more efficient and equally distributed concentration throughout extended period of time can be achieved. This paper is describing the process of obtaining poly(dl-lactide-co-glycolide) (DLPLG) nanospheres (110-170 nm) using chemical method with solvent/non-solvent systems where obtained solutions have been centrifuged. The encapsulation of the ascorbic acid in the polymer matrix is performed by homogenisation of water and organic phases. Nanoparticles of the copolymer DLPLG with the different contents of the ascorbic acid have different morphological characteristics, i.e. variable degree of uniformity, agglomeration, sizes and spherical shaping. The degradation of the nanospheres of DLPLG, DLPLG/ascorbic acid nanoparticles and release rate of the ascorbic acid were studied for 8 weeks in a physiological solution (0.9% sodium chloride in water). The samples have been characterised by infrared spectroscopy (IR), scanning electron microscopy (SEM), stereological analysis and ultraviolet (UV) spectroscopy.     

Synthesis,Anticancer Potential and Comprehensive Toxicity Studies of Novel Brominated Derivatives of Bacterial Biopigment Prodigiosin from Serratia marcescens ATCC 27117

Prodigiosins (prodiginines) are a class of bacterial secondary metabolites with remarkable biological activities and color. In this study, optimized production, purification, and characterization of prodigiosin (PG) from easily accessible Serratia marcescens ATCC 27117 strain has been achieved to levels of 14 mg/L of culture within 24 h. Furthermore, environmentally friendly bromination of produced PG was used to afford both novel mono- and dibrominated derivatives of PG. PG and its Br derivatives showed anticancer potential with IC₅₀ values range 0.62–17.00 µg/mL for all tested cancer cell lines and induction of apoptosis but low selectivity against healthy cell lines. All compounds did not affect Caenorhabditis elegans at concentrations up to 50 µg/mL. However, an improved toxicity profile of Br derivatives in comparison to parent PG was observed in vivo using zebrafish (Danio rerio) model system, when 10 µg/mL applied at 6 h post fertilization caused death rate of 100%, 30% and 0% by PG, PG-Br, and PG-Br_2, respectively, which is a significant finding for further structural optimizations of bacterial prodigiosins. The drug-likeness of PG and its Br derivatives was examined, and the novel Br derivatives obey the Lipinski’s “rule of five”, with an exemption of being more lipophilic than PG, which still makes them good targets for further structural optimization.     

Human and Bacterial Toll-Interleukin Receptor Domains Exhibit Distinct Dynamic Features and Functions

Toll-interleukin receptor (TIR) domains have emerged as critical players involved in innate immune signaling in humans but are also expressed as potential virulence factors within multiple pathogenic bacteria. However, there has been a shortage of structural studies aimed at elucidating atomic resolution details with respect to their interactions, potentially owing to their dynamic nature. Here, we used a combination of biophysical and biochemical studies to reveal the dynamic behavior and functional interactions of a panel of both bacterial TIR-containing proteins and mammalian receptor TIR domains. Regarding dynamics, all three bacterial TIR domains studied here exhibited an inherent exchange that led to severe resonance line-broadening, revealing their intrinsic dynamic nature on the intermediate NMR timescale. In contrast, the three mammalian TIR domains studied here exhibited a range in terms of their dynamic exchange that spans multiple timescales. Functionally, only the bacterial TIR domains were catalytic towards the cleavage of NAD⁺, despite the conservation of the catalytic nucleophile on human TIR domains. Our development of NMR-based catalytic assays allowed us to further identify differences in product formation for gram-positive versus gram-negative bacterial TIR domains. Differences in oligomeric interactions were also revealed, whereby bacterial TIR domains self-associated solely through their attached coil-coil domains, in contrast to the mammalian TIR domains that formed homodimers and heterodimers through reactive cysteines. Finally, we provide the first atomic-resolution studies of a bacterial coil-coil domain and provide the first atomic model of the TIR domain from a human anti-inflammatory IL-1R8 protein that undergoes a slow inherent exchange.     

90Sr/90Y determination in milk by Cherenkov radiation after microwave digestion

Journal of Radioanalytical and Nuclear Chemistry - A separation procedure was developed and implemented for the isolation of gold (Au) and platinum (Pt) radionuclides from deuteron irradiated Pt...     

Triazole-tethered ferrocene-quinoline conjugates: solid-state structure analysis,electrochemistry and theoretical calculations

Structural Chemistry - Ferrocenyl-, triazole- and quinoline-containing compounds are known to possess potential for biological activities. The synthesis and biological activities of O-alkylated...     

Study of uranium biosorption process in aqueous solution by red beet peel

Journal of Radioanalytical and Nuclear Chemistry - Red beet peel was utilized for U(VI) removal in a batch system. The characterization of prepared biosorbent was performed by Fourier transform...     

Composition and antimicrobial activity of Seseli montanum subsp. tommasinii essential oil

The essential oil isolated from Seseli montanum L. subsp. tommasinii Reich. f. was analyzed by GC/MS and the most abundant components were beta-pinene (30.2%), germacrene D (10.1%), sabinene (8.0%), alpha-pinene (7.2%) and limonene (6.6%). The antimicrobial effect of the essential oil was evaluated against four bacterial and four fungal species among which were food contaminants, spoilage fungi, and plant, fungal and animal pathogens. The oil possessed moderate to strong antimicrobial activity.