92 research outputs found

    An integrating study of genetic diversity and ecological niche modelling in Salvia aristata (Lamiaceae)

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    Applying both molecular data and ecological niche modelling is essential to infer the speciation mechanism and species delimitation in organisms. Salvia aristata Auch. ex Benth is an endemic species restricted to western, northwestern and centre of Iran and eastern parts of Turkey with variations in morphological character along its distributions. In this study, we applied SRAP marker and ecological niche modelling using climatic and geographic data to detect and examine the genetic structure and niche differentiation in S. aristata accessions. SRAP marker’s results showed 242 bands highly polymorph. Genetic distance analysis provided two main clusters. The STRUCTURE analysis provided two distinct ecotypes (K = 2). Our ecological niche model produced good results with high performance based on area under curve (AUC > 0.9) for both ecotypes. Altitude was the most important variable contributing in niche model of both ecotypes. The niche space of both ecotypes is different based on niche identity test and background test as well. Based on genetic and ecological evidence, it is concluded that S. aristata gene pool underwent a parapatric speciation process caused by niche divergence and reproductive isolations as a consequence of divergent selection on floral traits

    A revision of chestnut-leaved oak (Quercus castaneifolia C. A. Mey.; Fagaceae) in Hyrcanian Forests of Iran

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    Chestnut-leaved oak (Quercus castaneifolia C. A. Mey) is one of the most important native oaks of Iran distributed in the Hyrcanian Forests. The pure and mixed stands of it cover about 6.5% of these forests. The species represents morphological variations which have resulted in the description of several infraspecific taxa by different authors. Eight taxa were recognized as subspecies and varieties of Q. castaneifolia. In this survey, a set of quantitative and qualitative micro-morphological characteristics such as type of trichome, number and length of trichome rays, type of epicuticular waxes, type and shape of stomata, shape and sculptural features of pollen exine were studied using light microscopy and scanning electron microscopy. These characters were analyzed by the discriminant analysis method and combined with the macromorphological characters to designate the variation within the species and to evaluate the existing infraspecific taxa. Based on our results, the studied taxa are defined into four infraspecific taxa as follows: Q. castaneifolia subsp. castaneifolia var. castaneifolia, Q. castaneifolia subsp. castaneifolia var. minuta, Q. castaneifolia subsp. aitchisoniana, Q. castaneifolia subsp. undulate. The studied characteristics showed to be diagnostic for identification of the infraspecific taxa

    Dizaj i statistička optimizacija liposfera s glipizidom pomoću metodologije odgovora površine

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    A 32 factorial design was employed to produce glipizide lipospheres by the emulsification phase separation technique using paraffin wax and stearic acid as retardants. The effect of critical formulation variables, namely levels of paraffin wax (X1) and proportion of stearic acid in the wax (X2) on geometric mean diameter (dg), percent encapsulation efficiency (% EE), release at the end of 12 h (rel12) and time taken for 50% of drug release (t50), were evaluated using the F-test. Mathematical models containing only the significant terms were generated for each response parameter using the multiple linear regression analysis (MLRA) and analysis of variance (ANOVA). Both formulation variables studied exerted a significant influence (p < 0.05) on the response parameters. Numerical optimization using the desirability approach was employed to develop an optimized formulation by setting constraints on the dependent and independent variables. The experimental values of dg, % EE, rel12 and t50 values for the optimized formulation were found to be 57.54 ± 1.38 µm, 86.28 ± 1.32 %, 77.23 ± 2.78 % and 5.60 ± 0.32 h, respectively, which were in close agreement with those predicted by the mathematical models. The drug release from lipospheres followed first-order kinetics and was characterized by the Higuchi diffusion model. The optimized liposphere formulation developed was found to produce sustained anti-diabetic activity following oral administration in rats.32 faktorijalni dizajn primijenjen je za pripravu liposfera s glipizidom metodom separacije pomoću emulzija koristeći parafinski vosak i starinsku kiselinu kao tvari za usporavanje. Pomoću F-testa praćen je učinak kritičnih varijabli tijekom formuliranja, tj. količina parafinskog voska (X1) i udio stearinske kiseline (X2) na srednji promjer liposfera (dg), postotak inkapsulirane ljekovite tvari (% EE), oslobađanje ljekovite tvari nakon 12 h (rel12) te vrijeme potrebno za oslobađanje 50% ljekovite tvari (t50). Pomoću multiple linearne regresijske analize (MLRA) i analize varijabli (ANOVA) za svaki su parametar načinjeni matematički modeli koji sadrže samo značajne varijable. Proučavanje varijabli na oba načina ukazalo je na njihov značajan utjecaj (p < 0,05) na parametre liposfera. Postavljanjem ograničenja na zavisne i nezavisne varijable provedena je numerička optimizacija na principu poželjnosti. Eksperimentalne vrijednosti dg, % EE, rel12 i t50 optimiziranih formulacija bile su 57,54 ± 1,38 µm, 86,28 ± 1,32%, 77,23 ± 2,78% i 5,60 ± 0,32 h. Dobivene eksperimentalne vrijednosti iznosile su vrlo slične vrijednostima predviđenim matematičkim modelima. Oslobađanje glipizida iz liposfera slijedio je kinetiku prvog reda i okarakterizirano je Higuchijevim difuzijskim modelom. Optimizirane liposfere su nakon peroralne primjene na štakorima pokazale produljeni antidijabetički učinak

    Shift of the western boundary of the distribution area of Micromeria cristata (Hampe) Griseb. and Steptorhamphus tuberosus (Jacq.) Grossh.

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    During field investigations of Mt Rumija, two new taxa for the flora of Montenegro were recorded: Micromeria cristata (Hampe) Griseb. and Steptorhamphus tuberosus (Jacq.) Grossh. From the phytogeographic point of view these data indicate a change in the distribution area of both taxa, which have shifted to the west. Ashort overview of the taxonomic treatment of both genera is given

    Fast and Robust Edge-Based Localization in the Sony Four-Legged Robot League

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    This paper presents a fast approach for edge-based self-localization in RoboCup. The vision system extracts edges between the field and field lines, borders, and goals following a grid-based approach without processing whole images. These edges are employed for the selflocalization of the robot. Both image processing and self-localization work in real-time on a Sony Aibo, i. e. at the frame rate of the camera. The localization..

    A Palynological Study of Some Helichrysum (Asteraceae) Species in Iran

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    In this study, palynological characteristics of 23 specimens of Helichrysum Mill., representing 12 Iranian species were investigated. We evaluated pollen grains (25 per specimens) and tested them by 15 qualitative and quantitative characteristics using Scanning Electron Microscopy (SEM). Pollen grain descriptions of most species were presented for the first time in the world. The pollen grains were tricolporate, radially symmetrical and isopolar in all examined samples. They were small, and rarely medium in size. The polar outline view (amb) was the same among the species. The overall views of pollen grains were prolate-spheroidal, oblate-spheroidal, subprolate, prolate and spheroidal. However, the more abundant type was prolate-spheroidal. The exine sculpture was echinate, and tectum is perforate. The ANOVA test revealed a significant variation ( P < 0.001) for all the quantitative characteristics. In PCA analysis, the colpus length, width, and length/width ratio traits, polar and equatorial axes length, were the most variable features and some species were characterised by these characters. Results indicated that a few qualitative characteristics such as polar outline view and exine sculpture lack taxonomic importance via their stability among species. Also, the palynological traits had enough potential to separate the taxonomic boundaries of H. rubicundum and H. globiferum , but approximately the species clustering pattern did not agree with Flora Iranica

    Analysis of flat terrain for the Atlas robot

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    This paper gives a description of an approach to analyze the sensor information of the surroundings to select places where the foot of a humanoid can be placed. This will allow apply such robot in a rescue scenario, as foreseen in the DARPA Robotics Challenge, where a robot is forced to traverse difficult terrain
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