Ecologically acceptable usage of derivatives of essential oil of sweet basil, Ocimum basilicum, as antifeedants against larvae of the gypsy moth, Lymantria dispar

Ethanol solutions of five fractions obtained from essential oil of sweet basil Ocimum basilicum L. (Lamiales: Lamiaceae) (F1-F5) were tested for their antifeedant properties against 2nd instar gypsy moth larvae, Lymantria dispar L. (Lepidoptera: Lymantriidae), in laboratory non-choice and feeding-choice experiments. Prior to bioassays, the chemical composition of each fraction was determined by gas chromatography analyses. Significant larval deterrence from feeding was achieved by application of tested solutions to fresh leaves of the host plant. The most effective were F1 (0.5%), F4 (0.05, 0.1, and 0.5%), and F5 (0.1 and 0.5%), which provided an antifeedant index > 80% after five days. A low rate of larval mortality was observed in no-choice bioassay. In situ screening of chlorophyll fluorescence as an indicator of plant stress level (assessed by the induced fluorometry) confirmed that the tested compounds did not cause alternations in the photosynthetic efficiency of treated leaves

Modelling the light-curves of objects tidally disrupted by a black hole

Tidal disruption by massive black holes is a phenomenon, during which a large part of gravitational energy can be released on a very short time-scale. The time-scales and energies involved during X-ray and IR flares observed in Galactic centre suggest that they may be related to tidal disruption events. Furthermore, aftermath of a tidal disruption of a star by super-massive black hole has been observed in some galaxies, e.g. RX J1242.6-1119A. All these discoveries increased the demand for tools for tidal disruption study in curved space-time. Here we summarise our study of general relativistic effects on tidal deformation of stars and compact objects.Comment: 2 pages, to appear in the proceedings of the JENAM 2008, Symposium 7: "Grand Challenges in Computational Astrophysics

Convoluted CC-cosine functions and semigroups. Relations with ultradistribution and hyperfunction sines

Convoluted $C$-cosine functions and semigroups in a Banach space setting extending the classes of fractionally integrated $C$-cosine functions and semigroups are systematically analyzed. Structural properties of such operator families are obtained. Relations between convoluted $C$-cosine functions and analytic convoluted $C$-semigroups, introduced and investigated in this paper are given through the convoluted version of the abstract Weierstrass formula which is also proved in the paper. Ultradistribution and hyperfunction sines are connected with analytic convoluted semigroups and ultradistribution semigroups. Several examples of operators generating convoluted cosine functions, (analytic) convoluted semigroups as well as hyperfunction and ultradistribution sines illustrate the abstract approach of the authors. As an application, it is proved that the polyharmonic operator $(-\Delta)^{2^{n}},$ $n\in {\mathbb N},$ acting on $L^{2}[0,\pi]$ with appropriate boundary conditions, generates an exponentially bounded $K_{n}$-convoluted cosine function, and consequently, an exponentially bounded analytic $K_{n+1}$-convoluted semigroup of angle $\frac{\pi}{2},$ for suitable exponentially bounded kernels $K_{n}$ and $K_{n+1}.

Transport of silver nanoparticles from nanocomposite Ag/alginate hydrogels under conditions mimicking tissue implantation

The aim of this work was to assess phenomena occurring during AgNP transport from nanocomposite Ag/alginate hydrogels under conditions relevant for potential biomedical applications as antimicrobial soft tissue implants. First, we have studied AgNP migration from the nanocomposite to the adjacent alginate hydrogel mimicking soft tissue next to the implant. AgNP deposition was carried out by the initial burst release lasting for similar to 24 h yielding large aggregates on hydrogel surfaces and smaller clusters (similar to 400 nm in size) inside. However, the overall released content was low (0.67%) indicating high nanocomposite stability. In the next experimental series, release of AgNPs, 10-30 nm in size, from Ag/alginate microbeads in water was investigated under static conditions as well as under continuous perfusion mimicking vascularized tissues. Mathematical modeling has revealed AgNP release by diffusion under static conditions with the diffusion coefficient within the Ag/alginate hydrogel of 6.9x10(-19) m(2) s(-1). Conversely, continuous perfusion induced increased AgNP release by convection with the interstitial fluid velocity estimated as 4.6 nm s(-1). Overall, the obtained results indicated the influence of hydrodynamic conditions at the implantation site on silver release and potential implant functionality, which should be investigated at the experimentation beginning using appropriate in vitro systems

Activation energies as the validity criterion of a model for complex reactions that can be in oscillatory states

Modeling of any complex reaction system is a difficult task. If the system under examination can be in various oscillatory dynamic states, the apparent activation energies corresponding to different pathways may be of crucial importance for this purpose. In that case the activation energies can be determined by means of the main characteristics of an oscillatory process such as pre-oscillatory period, duration of the oscillatory period, the period from the beginning of the process to the end of the last oscillation, number of oscillations and others. All is illustrated on the Bray-Liebhafsky oscillatory reaction

Analytical time-like geodesics

Time-like orbits in Schwarzschild space-time are presented and classified in a very transparent and straightforward way into four types. The analytical solutions to orbit, time, and proper time equations are given for all orbit types in the form r=r(\lambda), t=t(\chi), and \tau=\tau(\chi), where \lambda\ is the true anomaly and \chi\ is a parameter along the orbit. A very simple relation between \lambda\ and \chi\ is also shown. These solutions are very useful for modeling temporal evolution of transient phenomena near black holes since they are expressed with Jacobi elliptic functions and elliptic integrals, which can be calculated very efficiently and accurately.Comment: 15 pages, 10 figures, accepted by General Relativity and Gravitatio

Provera validnosti Le Belovog dvodimenzionalnog modela sujete u Srbiji

LeBel constructed a Vanity Scale that measures two dimensions: Excessive Physical View and Excessive Abilities View. The main goal of the research was to adapt LeBel's Vanity Scale for the Serbian language, as well as to check the scale's external validity. In addition, we were also interested in whether the dimensions of vanity are mediators of the relationship between pathological narcissism, perfectionism, public self-absorption, and hubristic pride, on the one hand, and stress coping strategies that focus on emotions and avoidance, on the other. The dissertation is organized into three separate studies. The results of the first survey, on a convenient sample of 617 respondents (370 female persons; M = 34 years old), indicate that there is an equivalence of measurement units between the two versions of the Vanity Scale. The Vanity Scale in Serbian consists of 22 items and measures two dimensions. The reliability of the dimension Excessive Physical View is α = .770, and of the dimension Excessive Abilities View is α = .785. The results of the following research, which was conducted on a convenient sample of 518 respondents (216 male persons; M = 28.99 years old), indicate that the Excessive Physical View as a dimension of vanity is negatively correlated with Honesty–Humility, Emotionality, Depression, and Anxiety; and positively with Extraversion, Conscientiousness, and Openness to Experience. The other dimension of vanity, Excessive Abilities View, is positively correlated with Honesty–Humility, Emotionality, and Anxiety; and a negative correlation was found with Extraversion, Conscientiousness, Openness to Experience, and global Self-Esteem. The last research was conducted on a convenient sample of 510 respondents (264 female persons; M = 31.89 years). The results of the research indicate that the Excessive Physical View can be a mediator of the relationship between maladaptive perfectionism, pathological forms of narcissism, public self-absorption, and hubristic pride, on the one hand, and avoidance coping with stress, on the other hand. From all of the above, we can conclude that the Serbian adaptation of the Vanity Scale is a reliable and a valid measure of the two dimensions of vanity. In addition, the assumption that vanity is a maladaptive construct is not complete confirmed