نتایج جستجو برای: pine cones
تعداد نتایج: 28479 فیلتر نتایج به سال:
In the current context of considerable interest in palladium (Pd), a new process Pd biosorption is described with various natural materials derived from plant feedstocks. Eichhornia crassipes was chosen as model for determining thermodynamic and kinetic parameters biosorption. The optimised then tested on other (wheat, pine cones, coffee grounds, green tea grounds), powders dead native (Mentha ...
Changes in the quality of water reaching forest floor are of the most important consequences of native and exotic tree species plantations for rehabilitating the derelict areas of the Caspian forests. The aim of this study was to compare the chemical composition of throughfall in plantations of Persian maple (Acer velutinim Bioss) and Turkish Pine (Pinus brutia Ten) in Darabkola Forest, Sa...
Phenotypic variation among individuals is necessary for natural selection to operate and is therefore essential for adaptive evolution. However, extensive variation within individuals can mask variation among individuals and weaken the potential for selection. Here we quantify variation among and within individuals in female cone and seed traits of whitebark pine (Pinus albicaulis). In many pla...
PREMISE OF THE STUDY Population genetic analyses provide information on the population context in which evolutionary processes operate and are important for understanding the evolution of geographically variable traits. Earlier studies showed that cone structure of lodgepole pine in the Rocky Mountains diverged among populations because of geographic variation in coevolutionary interactions inv...
Masting promotes individual- and population-level reproduction by increasing pollination efficiency.
Masting is a reproductive strategy defined as the intermittent and synchronized production of large seed crops by a plant population. The pollination efficiency hypothesis proposes that masting increases pollination success in plants. Despite its general appeal, no previous studies have used long-term data together with population- and individual-level analyses to assess pollination efficiency ...
Introduction The most common approach for obturation of roots, which are treated endodontically, is lateral condensation. Finger spreaders have an essential role in packing the gutta-percha cones. We carried out this research to compare the compaction index of root canal obturation obtained with stainless steel (SS) spreader, nickel-titanium (NiTi) spreader, and different gutta-percha tapers. ...
Pattern formation in reaction-diffusion systems is often invoked as a mechanism for biological morphogenesis. Patterns in chemical systems typically occur either as propagating waves or as stationary, spatially periodic, Turing structures. The spiral and concentric (target) waves found to date in spatially extended chemical or physical systems are smooth and continuous; only living systems, suc...
Pattern formation in reaction-diffusion systems is often invoked as a mechanism for biological morphogenesis. Patterns in chemical systems typically occur either as propagating waves or as stationary, spatially periodic, Turing structures. The spiral and concentric (target) waves found to date in spatially extended chemical or physical systems are smooth and continuous; only living systems, suc...
The periodically forced Brusselator model displays temporal mixed-mode and quasiperiodic oscillations, period doubling, and chaos. We explore the behavior of such media as reaction-diffusion systems for investigating spiral instabilities. Besides near-core breakup and far-field breakup resulting from unstable modes in the radial direction or Doppler-induced instability (destabilization of the c...
Study of needle morphometric indices in Scots pine in the remote period after the Chernobyl accident
Biological effects in Scots pine populations experiencing chronic radiation exposure at doses up to 130 mGy per year as a result of the Chernobyl accident were studied in 2011 and 2013, using needle indices as endpoints. No relationships between the length, the mass of needles and the asymmetry in weight of paired needles and radiation exposure were revealed. The frequency of necrotic needles i...
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