A synergistic mixture of diatomaceous earth and deltamethrin to control stored grain insects

In order to mitigate the negative effect of diatomaceous earth (DE) on bulk density and grain flowability, DE was mixed with other insecticides. This paper investigates the efficacy of a mixture of DE and deltamethrin against Sitophilus zeamais, the maize weevil, Rhyzopertha dominica, the lesser grain borer, and Tribolium castaneum, the red flour beetle. Five mixtures of DE and deltamethrin were prepared in the laboratory containing the same quantity of DE and different concentrations of the active ingredient of deltamethrin. The ratio of DE and deltamethrin in formulations were: DE 1 part: deltamethrin 0.00025, 0.00050, 0.00075, 0.0010 and 0.00125 parts. Co-toxicity and Co-efficient values higher than 100 (S. zeamais 170–386, R. dominica 188–601, and T. castaneum 157–285) indicated synergism between DE and deltamethrin.Keywords: Diatomaceous earth, Deltamethrin, Ready to use mixture, Co-toxicity, Co-efficient, Synergism, Grain insect pest

The Generalized Star Product and the Factorization of Scattering Matrices on Graphs

In this article we continue our analysis of Schr\"odinger operators on arbitrary graphs given as certain Laplace operators. In the present paper we give the proof of the composition rule for the scattering matrices. This composition rule gives the scattering matrix of a graph as a generalized star product of the scattering matrices corresponding to its subgraphs. We perform a detailed analysis of the generalized star product for arbitrary unitary matrices. The relation to the theory of transfer matrices is also discussed

Parallel updating cellular automaton models of driven diffusive Frenkel-Kontorova-type systems

Three cellular automaton (CA) models of increasing complexity are introduced to model driven diffusive systems related to the generalized Frenkel-Kontorova (FK) models recently proposed by Braun [Phys.Rev.E58, 1311 (1998)]. The models are defined in terms of parallel updating rules. Simulation results are presented for these models. The features are qualitatively similar to those models defined previously in terms of sequentially updating rules. Essential features of the FK model such as phase transitions, jamming due to atoms in the immobile state, and hysteresis in the relationship between the fraction of atoms in the running state and the bias field are captured. Formulating in terms of parallel updating rules has the advantage that the models can be treated analytically by following the time evolution of the occupation on every site of the lattice. Results of this analytical approach are given for the two simpler models. The steady state properties are found by studying the stable fixed points of a closed set of dynamical equations obtained within the approximation of retaining spatial correlations only upto two nearest neighboring sites. Results are found to be in good agreement with numerical data.Comment: 26 pages, 4 eps figure

THE TRAITS OF SEED AND SEEDLINGS OF ALFALFA GENOTYPES UNDER THE INFLUENCE OF TEMPERATURE AND pH VALUES

Cilj rada bio je procijeniti utjecaj genotipa, temperature i pH na energiju klijanja i klijavost sjemena, te dužinu korijena i hipokotila klijanaca tri kultivara lucerne (Slavonka, Stela i Vuka), sa svrhom procjene mogućnosti izbora genotipova za sjetvu na tlima s različitim pH i pri različitim temperaturama u najranijim fazama razvoja. Pokus je postavljen u četiri ponavljanja na dvije temperature: 20oC; 10oC i dvije razine pH: 7,25; 5,05. Značajna razlika utvrđena je između genotipova za svojstvo dužine korijena (p=0,01). Razlike u energiji klijanja i dužini hipokotila na različitim temperaturama bile su značajne (p= 0,01). Značajnost pH utvrđena je za svojstva dužine korijena i hipokotila (p=0,01 i p=0,05). Interakcija genotip x temperatura bila je značajna za sva proučavana svojstva (p=0,01 i p=0,05), dok je interakcija genotip x pH utvrđena za dužinu hipokotila (p=0,01). Dužina korijena bila je značajno niža kod kultivara Slavonka (2,16 cm) i značajno viša kod kultivara Stela (2,83 cm). Energija klijanja bila je značajno viša pri 20oC, dok je dužina hipokotila bila značajno niža pri istoj temperaturi. Dužina korijena i hipokotila bili su značajno viši kod pH razine 5,05. Rezultati ukazuju da interakcija genotipa i temperature u najvećoj mjeri utječe na najraniji porast lucerne. Premda je razina pH utjecala na rast klijanaca potrebna su dodatna istraživanja da bi se moglo procijeniti postoji li mogućnost izbora genotipova za sjetvu na tlima s različitim pH u stadiju klijanja sjemena.The objective of the study was to evaluate the influence of genotype, temperature and pH values on germination energy, seed germination, and root and hypocotil length of seedlings of three alfalfa cultivars (Slavonka, Stela and Vuka) with the aim to assess possibilities for choosing suitable genotypes for sowing in the soil of different pH and temperature levels in the earliest stages of development. The experiment was set up in four replications at two levels of temperature: 20°C and 10°C, and two pH levels: 7.25 and 5.05. A significant difference in genotypes was determined for root length (p=0.01). Differences in energy of germination and hypocotil length at different temperatures were found to be significant (p= 0.01). Significance of pH was determined for root and hypocotil length (p=0.01 and p=0.05). Interaction genotype x temperature was significant in all traits tested (p=0.01 and p=0.05), with interaction genotype x pH determined for hypocotil length (p=0.01). Root length was significantly lower in the Slavonka cultivar (2.16 cm) and significantly higher in the Stela cultivar (2.83 cm). Energy of germination was significantly higher at 20°C, with hypocotil length significantly lower at the same temperature. Root and hypocotil lenght were significantly higher at pH level of 5.05. The results show that interaction of genotype and temperature influence to the fullest extent the earliest growth of alfalfa. Though pH level influenced seedlings growth, further examinations are needed to assess possibilities for choosing genotypes for sowing in the soil of different pH levels at the stage of seed germination

Dynamic response of HTS composite tapes to pulsed currents

Dynamic voltage-current characteristics of an HTS Ag/BiSCCO composite tape are studied both experimentally and theoretically. The tape is subjected by pulsed currents with different shapes and magnitude and voltage traces are measured using the four-point method with different location of potential taps on the sample surface. Clockwise and anticlockwise hysteresis loops are obtained for the same sample depending on location of the potential taps. The dynamic characteristics deviate substantially from the DC characteristic, especially in the range of low voltages where a criterion for the critical current value is usually chosen (1-10 mkV/cm). The critical current determined from dynamic characteristics and its change with the pulse magnitude depend on location of the potential taps and on the curve branch chosen for the critical current determination (ascending or descending). The theoretical analysis is based on a model of the magnetic flux diffusion into a composite tape for a superconductor described by the flux creep characteristic. Numerical simulation based on this model gives the results in good agreement with the experimental ones and explains the observed peculiarities of the dynamic characteristics of HTS composite tapes. The difference between the magnetic diffusion into a tape and a slab is discussed.Comment: 18 pages, 13 figure

A single-mode quantum transport in serial-structure geometric scatterers

We study transport in quantum systems consisting of a finite array of N identical single-channel scatterers. A general expression of the S matrix in terms of the individual-element data obtained recently for potential scattering is rederived in this wider context. It shows in particular how the band spectrum of the infinite periodic system arises in the limit $N\to\infty$. We illustrate the result on two kinds of examples. The first are serial graphs obtained by chaining loops or T-junctions. A detailed discussion is presented for a finite-periodic "comb"; we show how the resonance poles can be computed within the Krein formula approach. Another example concerns geometric scatterers where the individual element consists of a surface with a pair of leads; we show that apart of the resonances coming from the decoupled-surface eigenvalues such scatterers exhibit the high-energy behavior typical for the delta' interaction for the physically interesting couplings.Comment: 36 pages, a LaTeX source file with 2 TeX drawings, 3 ps and 3 jpeg figures attache

Importing genetically altered animals : ensuring quality

The reproducibility of research using laboratory animals requires reliable management of their quality, in particular of their genetics, health and environment, all of which contribute to their phenotypes. The point at which these biological materials are transferred between researchers is particularly sensitive, as it may result in a loss of integrity of the animals and/or their documentation. Here, we describe the various aspects of laboratory animal quality that should be confirmed when sharing rodent research models. We also discuss how repositories of biological materials support the scientific community to ensure the continuity of the quality of laboratory animals. Both the concept of quality and the role of repositories themselves extend to all exchanges of biological materials and all networks that support the sharing of these reagents.Peer reviewe

Time-Resolved Studies of Stick-Slip Friction in Sheared Granular Layers

Sensitive and fast force measurements are performed on sheared granular layers undergoing stick-slip motion, along with simultaneous imaging. A full study has been done for spherical particles with a +-20% size distribution. Stick-slip motion due to repetitive fluidization of the layer occurs for low driving velocities. Between major slip events, slight creep occurs that is variable from one event to the next. The effects of changing the stiffness k and velocity V of the driving system are studied in detail. The stick-slip motion is almost periodic for spherical particles over a wide range of parameters, but becomes irregular when k is large and V is relatively small. At larger V, the motion becomes smoother and is affected by the inertia of the upper plate bounding the layer. Measurements of the period T and amplitude A of the relative motion are presented as a function of V. At a critical value Vc, a transition to continuous sliding motion occurs that is discontinuous for k not too large. The time dependence of the instantaneous velocity of the upper plate and the frictional force produced by the granular layer are determined within individual slipping events. The force is a multi-valued function of the instantaneous velocity, with pronounced hysteresis and a sudden drop prior to resticking. Measurements of vertical displacement reveal a small dilation of the material (about one tenth of the mean particle size in a layer 20 particles deep) associated with each slip event. Finally, optical imaging reveals that localized microscopic rearrangements precede (and follow) each slip event. The behavior of smooth particles is contrasted with that of rough particles.Comment: 20, pages, 17 figures, to appear in Phys. Rev.

Russia’s Eurasian past, present and future: rival international societies and Moscow’s place in the post-cold war world

The failure of post-Soviet Russia to integrate into the West became evident with the 2014 Ukraine crisis, leading Moscow to accelerate its declared “pivot to the East”. However, the increased dependence on China carries its own risks, such as the danger of becoming Beijing’s junior partner. For an erstwhile superpower that continues to declare and prize its autonomy in international affairs, this is a particularly unappealing prospect. Thus, it remains to be seen whether a genuinely balanced partnership can exist between both countries. This article uses insights from Adam Watson’s pendulum theory to explore Russia’s post-2014 Eurasian predicament. We argue that the rapid rightward swing of the pendulum in the Euro-Atlantic order following the end of the Cold War has proven indigestible for Moscow. The article then moves to discuss the Sino-Russian relationship in the context of the emerging Eurasian space. It concludes that the growing disillusionment of Russian leaders with the West since the 2000s, along with the normative convergence between Moscow and Beijing, has led to a closer partnership between the two. Yet the partnership is also riddled with a number of insecurities on Moscow’s side that could undermine the long-term prospects for cooperation between Russia and China