Random Sequential Adsorption on Fractals

Irreversible adsorption of spheres on flat collectors having dimension $d<2$ is studied. Molecules are adsorbed on Sierpinski's Triangle and Carpet like fractals ($1<d<2$), and on General Cantor Set ($d<1$). Adsorption process is modeled numerically using Random Sequential Adsorption (RSA) algorithm. The paper concentrates on measurement of fundamental properties of coverages, i.e. maximal random coverage ratio and density autocorrelation function, as well as RSA kinetics. Obtained results allow to improve phenomenological relation between maximal random coverage ratio and collector dimension. Moreover, simulations show that, in general, most of known dimensional properties of adsorbed monolayers are valid for non-integer dimensions.Comment: 12 pages, 8 figure

Random packing of spheres in Menger sponge

Random packing of spheres inside fractal collectors of dimension 2 < d < 3 is studied numerically using Random Sequential Adsorption (RSA) algorithm. The paper focuses mainly on the measurement of random packing saturation limit. Additionally, scaling properties of density autocorrelations in the obtained packing are analyzed. The RSA kinetics coefficients are also measured. Obtained results allow to test phenomenological relation between random packing saturation density and collector dimension. Additionally, performed simulations together with previously obtained results confirm that, in general, the known dimensional relations are obeyed by systems having non-integer dimension, at least for d < 3.Comment: 13 pages, 6 figure

Algorithmic Complexity for Short Binary Strings Applied to Psychology: A Primer

Since human randomness production has been studied and widely used to assess executive functions (especially inhibition), many measures have been suggested to assess the degree to which a sequence is random-like. However, each of them focuses on one feature of randomness, leading authors to have to use multiple measures. Here we describe and advocate for the use of the accepted universal measure for randomness based on algorithmic complexity, by means of a novel previously presented technique using the the definition of algorithmic probability. A re-analysis of the classical Radio Zenith data in the light of the proposed measure and methodology is provided as a study case of an application.Comment: To appear in Behavior Research Method

Hepatitis C Virus Core Protein Induces Neuroimmune Activation and Potentiates Human Immunodeficiency Virus-1 Neurotoxicity

BACKGROUND: Hepatitis C virus (HCV) genomes and proteins are present in human brain tissues although the impact of HIV/HCV co-infection on neuropathogenesis remains unclear. Herein, we investigate HCV infectivity and effects on neuronal survival and neuroinflammation in conjunction with HIV infection. METHODOLOGY: Human microglia, astrocyte and neuron cultures were infected with cell culture-derived HCV or exposed to HCV core protein with or without HIV-1 infection or HIV-1 Viral Protein R (Vpr) exposure. Host immune gene expression and cell viability were measured. Patch-clamp studies of human neurons were performed in the presence or absence of HCV core protein. Neurobehavioral performance and neuropathology were examined in HIV-1 Vpr-transgenic mice in which stereotaxic intrastriatal implants of HCV core protein were performed. PRINCIPAL FINDINGS: HCV-encoded RNA as well as HCV core and non-structural 3 (NS3) proteins were detectable in human microglia and astrocytes infected with HCV. HCV core protein exposure induced expression of pro-inflammatory cytokines including interleukin-1β, interleukin-6 and tumor necrosis factor-α in microglia (p<0.05) but not in astrocytes while increased chemokine (e.g. CXCL10 and interleukin-8) expression was observed in both microglia and astrocytes (p<0.05). HCV core protein modulated neuronal membrane currents and reduced both β-III-tubulin and lipidated LC3-II expression (p<0.05). Neurons exposed to supernatants from HCV core-activated microglia exhibited reduced β-III-tubulin expression (p<0.05). HCV core protein neurotoxicity and interleukin-6 induction were potentiated by HIV-1 Vpr protein (p<0.05). HIV-1 Vpr transgenic mice implanted with HCV core protein showed gliosis, reduced neuronal counts together with diminished LC3 immunoreactivity. HCV core-implanted animals displayed neurobehavioral deficits at days 7 and 14 post-implantation (p<0.05). CONCLUSIONS: HCV core protein exposure caused neuronal injury through suppression of neuronal autophagy in addition to neuroimmune activation. The additive neurotoxic effects of HCV- and HIV-encoded proteins highlight extrahepatic mechanisms by which HCV infection worsens the disease course of HIV infection

Składniki biologiczne aktywne w wyciągach z jemioły jodły (Abies alba Mill.), sosny (Pinus sylvestris L.) i cisu (Taxus baccata L.)

Taking into account the growing number of reports which confirm the medicinal effects of preparations of plant origin, the paper analyzed the biochemical composition of extracts obtained from mistletoe parasitizing on fir and extracts from fir, pine and yew trees was analyzed. The mistletoe samples were collected in winter, spring, summer and autumn. Mistletoe’s extract is a source of viscotoxines – substances used in a treatment of heart diseases. Yew is also used as a plant which tissues contain substances of high therapeutic value. Extracts obtained from tissues of this plant are used for cancer treatment. The content of protein, soluble sugars and proline were determined in all samples. The biological activity of mistletoe may be connected with high concentrations of almost all investigated metabolites. The level of these compounds were higher than that of extracts from trees. An increased level of proline and malondialdehyde in the tissues of spring mistletoe is probably related to summary effect of environmental stresses in this season (temperature, insolation intensity and duration). Among polyamines, the highest concentration of spermidine in extracts from mistletoe and of spermine in extracts from trees may be a sign of specific metabolism pathway in investigated plants. Among extracts from trees tissues, fir was the richest in studied bioactive substances. The less amounts of all analyzed substances were found in tissues of pine.Biorąc pod uwagę rosnącą liczbę doniesień potwierdzających lecznicze działanie preparatów roślinnych, w niniejszej pracy analizie poddano parametry biochemiczne ekstraktów pozyskiwanych z jemioły (ze zbiorów w okresie zimowym, wiosennym, letnim i jesiennym), jodły, sosny i cisu. Ekstrakt jemiołowy jest bogatym źródłem składników bioaktywnych, takich jak m.in. wiskuminy, wiskotoskyny, aminy biogenne, związki terpenowe, związki fenolowe, alkaloidy czy flawonoidy. Do badań wykorzystano także potencjalnych żywicieli jemioły tj. jodłę i sosnę, oraz cis jako rośliny, których ekstrakty mają dużą wartość terapeutyczną. Dokonano analizy zawartości białka, cukrów rozpuszczalnych oraz proliny. O wysokiej aktywności biologicznej jemioły, może świadczyć fakt, iż w jej tkankach zaobserwowano prawie ośmiokrotnie wyższe stężenie białka, w porównaniu do tkanek jej żywicieli. Poziom proliny w tkankach jemioły jest ściśle związany z dostępnością do wody. Zbadano także stężenie sumarycznych lipidów oraz produktów peroksydacji lipidów (których miarą było stężenie aldehydu dimalonowgo). Obserwowany wzrost zawartości aldehydu dimalonylowego skorelowany jest ze wzrostem nasłonecznienia w okresie wiosennym, co skutkuje zwiększonym stresem oksydacyjnym. Analizie poddano także zawartość bioaktywnych poliamin oraz jonów potasu, chloru i wapnia w tkankach badanych roślin. Na podstawie uzyskanych wyników pomiarów biochemicznych stwierdzono, iż cykl roczny związany z okresem wegetacyjnym rośliny ma wpływ na skład biochemiczny tkanek jemioły i jest powiązany ze zmianami tych parametrów w tkankach jej żywicieli

Zawartość antyoksydantów w wyciągach z jemioły (Viscum album L.), jodły (Taxus baccata L.), sosny (Pinus sylvestris L.) i cisu (Abies alba Mill.)

Imbalance between the intensity of oxidative processes (that induce the formation of reactive oxygen species) and counteracting antioxidant system is called oxidative stress. Most of the pathological changes in living organisms is associated with the processes of carcinogenesis induced by free radicals. State of equilibrium is maintained due to the presence of antioxidant enzymes (e.g. superoxide dismutase, peroxidase) and other biologically active substances such as glutathione, ascorbic acid and beta-carotene. These compounds enable the removal of reactive oxygen species in cells. The purpose of this study was to investigate the oxidative activity of mistletoe extracts and their potential hosts: fir and pine, and yew trees, which also have therapeutic properties. The results of performed analysis of enzymatic antioxidants (superoxide dismutase and peroxidase) lead to the conclusion that their activity in the tissues of mistletoe is much lower than in the tissues of fir, pine and yew. It was found, however, a much higher content of non-enzymatic antioxidants such as ascorbic acid, glutathione or beta- carotene in the tissues of mistletoe compared to other plants analyzed. Thus, extracts from mistletoe are a rich source of antioxidants easily assimilated to organisms receiving them.Zaburzenie równowagi między natężeniem procesów oksydacyjnych, które indukują powstawanie reaktywnych form tlenu a przeciwdziałającym mu systemem antyoksydacyjnym określa się mianem stresu oksydacyjnego. Większość zmian patologicznych w organizmach związana jest z procesami kancerogenezy indukowanymi działaniem wolnych rodników. Stan równowagi utrzymywany jest dzięki obecności enzymów antyoksydacyjnych (np. dysmutazy ponadtlenkowej, peroksydazy) oraz innych substancji biologicznie czynnych, takich jak np. glutation, kwas askorbinowy czy β-karoten. Związki te umożliwiają usuwanie nadmiaru reaktywnych form tlenu z komórek. Celem pracy było zbadanie aktywności oksydacyjnej ekstraktów jemioły oraz jej potencjalnych żywicieli, jodły i sosny oraz cisu, który również ma właściwości terapeutyczne. Przeprowadzone analizy zawartości enzymatycznych antyoksydantów (dysmutazy ponadtlenkowej i peroksydazy) pozwalają stwierdzić, iż ich aktywność w tkankach jemioły jest znacznie niższa niż w tkankach jodły, sosny i cisu. Stwierdzono jednak znacznie wyższą zawartość antyoksydantów nieenzymatycznych, tj. kwasu askorbinowego, glutationu czy β-karotenu w tkankach jemioły w stosunku do pozostałych analizowanych roślin. Ekstrakty z jemioły są więc bogatym źródłem antyoksydantów łatwo przyswajalnych dla pobierających je organizmów