LEAF AREA INDEX IN WINTER WHEAT: RESPONSE ON SEED RATE AND NITROGEN APPLICATION BY DIFFERENT VARIETIES

The most important photosynthesis acceptor – leaf area vary among cultivation measures and it is limited factor for creating exact growth models in common winter wheat. The objective of this study was to investigate changes of leaf area index (LAI) affected by agricultural treatments – 4 sowing rates and 9 nitrogen treatments based on fertilising rates, target values based on soil mineral nitrogen and plant sap tests target values including different varieties. Increasing sowing rates from 350 to 800 viable seeds m-2 increased LAI at EC 75 stage from 2.9 to 5.5, where LAI 4.1 at 500 seeds m-2 did not vary between lower and higher rates; also at EC 85 stage LAIs did not differ significantly. At EC 75 stage LAI differed among control and nitrogen treatments from 1.0 to 6.5 and at EC 85 stage from 0.1 to 2.4, with differences in interaction among varieties. Higher nitrogen rates for first and second top dressing increased LAI in both stages compared without dressing treatments. Due to significant differences among LAI as consequence of production system, we suggest to take this into account in every prediction and modelling of growth in winter wheat.Listna površina, kot najpomembnejši fotosintetski akceptor je odvisna od pridelovalnih ukrepov in je omejitveni dejavnik za izdelavo natančnih rastnih modelov navadne ozimne pšenice. Cilj te študije je preveriti spremembe indeksa listne površine (LAI) pod vplivom agrotehničnih ukrepov – 4 gostot setve, 9 odmerkov dušika temelječih na odmerkih gnojil in temelječih na ciljnih vrednostih Nmin-a ter hitrih nitratnih rastlinskih testov vključujoč različne sorte. Povečevanje setvene norme od 350 do 800 kalivih semen m-2 povečuje LAI v fazi EC 75 od 2.9 do 5.5, medtem ko med njima in 500 kalivimi zrni m-2 značilnih razlik med LAI ni bilo; tudi v fazi EC 85 med LAI nismo ugotovili značilnih razlik. V fazi EC 75 je LAI variral od 1.0 v kontrolnem obravnavanju do 6.5 v gnojilnih obravnavanjih, v fazi EC 85 pa od 0.1 do 2.4, s tem da so bile značilne razlike tudi v interakciji s sortami. Višji odmerki dušika za prvo in drugo dognojevanje povečujejo LAI v obeh fazah v primerjavi z obravnavanji brez dognojevanja. Zaradi značilnih razlik med LAI kot posledica agrotehnike, priporočamo upoštevati razlike med LAI pri vsakem načrtovanju ali modeliranju rasti ozimne pšenice

PLA/WOOD BIOCOMPOSITES: IMPROVING COMPOSITE STRENGTH BY CHEMICAL TREATMENT OF THE FIBERS

A resol type phenolic resin was prepared for the impregnation of wood particles used for the reinforcement of PLA. A preliminary study showed that the resin penetrates wood with rates depending on the concentration of the solution and on temperature. Treatment with a solution of 1 wt% resin resulted in a considerable increase of composite strength and decrease of water absorption. Composite strength improved as a result of increased inherent strength of the wood, but interfacial adhesion might be modified as well. When wood was treated with resin solutions of larger concentrations, the strength of the composites decreased, first slightly, then drastically to a very small value. A larger amount of resin results in a thick coating on wood with inferior mechanical properties. At large resin contents the mechanism of deformation changes; the thick coating breaks very easily leading to the catastrophic failure of the composites at very small loads

1-Methyl-3-(2-methyl­phen­yl)-3,3a,4,9b-tetra­hydro-1H-chromeno[4,3-c][1,2]oxazole-3a-carbonitrile

In the title compound, C19H18N2O2, the five-membered isoxazole ring adopts an envelope conformation and the deviation of the N atom from the mean plane of the isoxazole ring is −0.3256 (11) Å. The pyran ring adopts a half-chair conformation. The isoxazole ring forms dihedral angles of 44.07 (7) and 84.23 (7)° with the pyran and methyl­benzene rings, respectively. The mol­ecular structure is stabilized by weak C—H⋯π inter­actions

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

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.

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

The Role of Eif6 in Skeletal Muscle Homeostasis Revealed by Endurance Training Co-expression Networks

Regular endurance training improves muscle oxidative capacity and reduces the risk of age-related disorders. Understanding the molecular networks underlying this phenomenon is crucial. Here, by exploiting the power of computational modeling, we show that endurance training induces profound changes in gene regulatory networks linking signaling and selective control of translation to energy metabolism and tissue remodeling. We discovered that knockdown of the mTOR-independent factor Eif6, which we predicted to be a key regulator of this process, affects mitochondrial respiration efficiency, ROS production, and exercise performance. Our work demonstrates the validity of a data-driven approach to understanding muscle homeostasis

ENZO: A Web Tool for Derivation and Evaluation of Kinetic Models of Enzyme Catalyzed Reactions

We describe a web tool ENZO (Enzyme Kinetics), a graphical interface for building kinetic models of enzyme catalyzed reactions. ENZO automatically generates the corresponding differential equations from a stipulated enzyme reaction scheme. These differential equations are processed by a numerical solver and a regression algorithm which fits the coefficients of differential equations to experimentally observed time course curves. ENZO allows rapid evaluation of rival reaction schemes and can be used for routine tests in enzyme kinetics. It is freely available as a web tool, at http://enzo.cmm.ki.si

Dll1 Haploinsufficiency in Adult Mice Leads to a Complex Phenotype Affecting Metabolic and Immunological Processes

BACKGROUND: The Notch signaling pathway is an evolutionary conserved signal transduction pathway involved in embryonic patterning and regulation of cell fates during development and self-renewal. Recent studies have demonstrated that this pathway is integral to a complex system of interactions, involving as well other signal transduction pathways, and implicated in distinct human diseases. Delta-like 1 (Dll1) is one of the known ligands of the Notch receptors. The role of the Notch ligands is less well understood. Loss-of-function of Dll1 leads to embryonic lethality, but reduction of Delta-like 1 protein levels has not been studied in adult stage. METHODOLOGY/PRINCIPAL FINDINGS: Here we present the haploinsufficient phenotype of Dll1 and a missense mutant Dll1 allele (Dll1(C413Y)). Haploinsufficiency leads to a complex phenotype with several biological processes altered. These alterations reveal the importance of Dll1 mainly in metabolism, energy balance and in immunology. The animals are smaller, lighter, with altered fat to lean ratio and have increased blood pressure and a slight bradycardia. The animals have reduced cholesterol and triglyceride levels in blood. At the immunological level a subtle phenotype is observed due to the effect and fine-tuning of the signaling network at the different levels of differentiation, proliferation and function of lymphocytes. Moreover, the importance of the proteolytic regulation of the Notch signaling network emphasized. CONCLUSIONS/SIGNIFICANCE: In conclusion, slight alterations in one player of Notch signaling alter the entire organism, emphasizing the fine-tuning character of this pathway in a high number of processes

Systems Biology in ELIXIR: modelling in the spotlight

info:eu-repo/semantics/publishedVersio