171,207 research outputs found
Dynamics of influenza with the rates of vaccination and treatment
No full textVural C. Dynamics of influenza with the rates of vaccination and treatment / C. Vural, E. Demir // Algebraic and geometric methods of analysis - 2024 : abstr. of the Intern. sci. conf., Odesa, 27-30 May - 2024 / [Odesa Nat. Univ. of Technology et al.] ; sci comm.: [ Yu. Fedchenko, N. Konovenko et al.]. – Odesa, 2024. – P. 128. – Ref.: 1 tit
Two new species of Echinops sect. Ritropsis (Asteraceae) from Turkey
No full textEchinops antalyensis C. Vural and Echinops borae C. Vural (both in sect. Ritropsis) are described as new species from South Anatolia, Turkey. A revised diagnostic key of the species of Echinops sect. Ritropsis in Turkey is given. The morphological differences from the closely related species are discussed. An IUCN threat category for the two new species is proposed and observations on the ecology of the populations are provided. The geographical distributions of the new species are preseted
Two new species of Echinops sect. Ritropsis (Asteraceae) from Turkey
No full textEchinops antalyensis C. Vural and Echinops borae C. Vural (both in sect. Ritropsis) are described as new species from South Anatolia, Turkey. A revised diagnostic key of the species of Echinops sect. Ritropsis in Turkey is given. The morphological differences from the closely related species are discussed. An IUCN threat category for the two new species is proposed and observations on the ecology of the populations are provided. The geographical distributions of the new species are preseted
The taxonomical revision of genus cota j.gay (asteraceae) in turkey
No full textBu çalışmada, Cota J. Gay (Asteraceae) cinsine ait taksonların morfolojik, palinolojik, moleküler ve sitogenetik özellikleri, tür tanıma anahtarları, tür betimleri ve coğrafi yayılışları sunulmuştur. Türkiye Florası'nda Cota cinsi Anthemis L. cinsinin 3 seksiyonundan biri olarak verilmiştir. Son yıllarda yapılan çalışmalar sonucunda Cota seksiyonuna ait taksonların tümü cins seviyesine yükseltilmiştir. Türkiye Florası'nda Cota seksiyonu tür ve türaltı seviyede 22 taksonla temsil edilmektedir. Türkiye için Cota cinsine ait yeni bir tür tespit edilmiştir (Cota hamzaoglui U.Özbek & Vural). Cota tinctoria L. var. euxina (Boiss.) Grierson ve C. tinctoria L. var. virescens Grierson taksonları tür seviyesine çıkartılarak Cota euxina (Boiss.) U.Özbek & Vural ve C. virescens (Grierson) U.Özbek & Vural adını almıştır. C. melanolepis Boiss. türü ülkemiz siyasi sınırları içinde yetişmediğinden listemizden çıkartılmıştır. Bu çalışma sonucunda Cota cinsi üyeleri tür ve türaltı seviyede 22 takson olarak değerlendirilmiştir. Bütün türlere fitocoğrafik bölge önerilmiştir. Ayrıca Türkiye Florası'nda endemik olarak belirtilen C. melanoloma Trautv. subsp. melanoloma ve C. wiedemanniana (Fisch. & C.A. Mey.) Holub türlerinin endemik olmadıkları tespit edilmiştir. Türkiye Bitkileri Kırmızı Kitabı'nda DD olarak değerlendirilen C. fulvida Boiss. türü tip lokalitesi dışında başka bir lokaliteden ilk kez toplanmıştır. RAPD ve SDS-PAGE verilerine göre taksonlar arasında farklılıklar tespit edilmiş ve moleküler sonuçların morfolojik bulguları desteklediği sonucuna varılmıştır. Cota cinsine ait taksonların polenlerinin morfolojik özellikleri birbirine oldukça benzemektedir. Taksonların polen tipleri trikolporat, polen şekilleri prolat-sferoidal ve oblat-sferoidal, süslenmeleri ise ekinattır. Çalışılan taksonların kromozom sayıları 2n=18'dir.In this study, morphological, palynological, molecular and cytogenetical characters have been discussed. The identification keys, descriptions and geographical distribution maps of taxa belonging to genus Cota J. Gay (Asteraceae) have been presented. Cota is given as one of three sections of the Anthemis in Flora of Turkey. As a result of recent studies sect. Cota have been elevated to genus level, and then all taxa attributed to this section transfered to the new genus. Genus Cota is represented by 22 taxa in the Flora of Turkey. A new species of the genus Cota has been described as Cota hamzaoglui U. Özbek & Vural. Cota tinctoria L. var. euxina (Boiss.) Grierson and C. tinctoria L. var. virescens Grierson has been arised to the species level as Cota euxina (Boiss.) U.Özbek & Vural and C. virescens (Grierson) U.Özbek & Vural. C. melanolepis Boiss. did not find throughout the political borders of our country, so it has been excluded from the list. As a result of this study Cota contains 22 taxa. The phytogeographic region for all species has been proposed. The endemisity of C. melanoloma Trautv. subsp. melanoloma and C. wiedemanniana (Fisch. & C.A. Mey.) Holub has not been confirmed, although they are endemic due to Flora of Turkey. C. fulvida Boiss., which is placed in DD category according to Red Data Book of Turkish Plants, has been collected for first time from another locality except of type locality. Results of RAPD and SDS-PAGE data have been approved the differences between the taxa. The molecular studies due to the taxa of this genus support the morphological features. Palinological characters of Cota species are very similar. The type of pollen grains are tricolporate, the shape of pollen grains are prolate-spheroidal and oblate-spheroidal, and ornamentations are echinate. The chromosome number of the examined taxa has been indicated as 2n=18
Dynamics of the lignin glass transition
No full textVURAL, DERYA/0000-0002-0120-3024; Petridis, Loukas/0000-0001-8569-060XWOS: 000442270800017PubMed: 30046795The dynamics of lignin, a complex and heterogeneous major plant cell-wall macromolecule, is of both fundamental and practical importance. Lignin is typically heated to temperatures above its glass transition to facilitate its industrial processing. We performed molecular dynamics simulations to investigate the segmental () relaxation of lignin, the dynamical process that gives rise to the glass transition. It is found that lignin dynamics involves mainly internal motions below T-g, while segmental inter-molecular motions are activated above T-g. The segments whose mobility is enhanced above T-g consist of 3-5 lignin monomeric units. The temperature dependence of the lignin segmental relaxation time changes from Arrhenius below T-g to Vogel-Fulcher-Tamman above T-g. This change in temperature dependence is determined by the underlying energy landscape being restricted below T-g but exhibiting multiple minima above T-g. The Q-dependence of the relaxation time is found to obey a power-law up to Q(max), indicative of sub-diffusive motion of lignin above T-g. Temperature and hydration affect the segmental relaxation similarly. Increasing hydration or temperature leads to: (1) the process starting earlier, i.e. the beta process becomes shortened, (2) Q(max) decreasing, i.e. the lengthscale above which subdiffusion is observed increases, and (3) the number of monomers constituting a segment increasing, i.e. the motions that lead to the glass transition become more collective. The above findings provide molecular-level understanding of the technologically important segmental motions of lignin and demonstrate that, despite the heterogeneous and complex structure of lignin, its segmental dynamics can be described by concepts developed for chemically homogeneous polymers.Genomic Science Program, Office of Biological and Environmental Research, U.S. Department of Energy (DOE) [FWP ERKP752]; Office of Science of the U. S. Department of EnergyUnited States Department of Energy (DOE) [DE-AC02-05CH11231]; DOEUnited States Department of Energy (DOE) [DE-AC05-00OR22725]This research was supported by the Genomic Science Program, Office of Biological and Environmental Research, U.S. Department of Energy (DOE), under Contract FWP ERKP752. This research used resources of the National Energy Research Scientific Computing Center, a DOE Office of Science User Facility supported by the Office of Science of the U. S. Department of Energy under Contract No. DE-AC02-05CH11231. Oak Ridge National Laboratory is managed by UT-Battelle, LLC, for DOE under Contract DE-AC05-00OR22725
Convergence analysis of blind image deconvolution via dispersion minimization
No full textA new non-linear adaptive filter called blind image deconvolution via dispersion minimization has recently been proposed for restoring noisy blurred images blindly. This is essentially a two-dimensional version of the constant modulus algorithm that is well known in the field of blind equalization. The two-dimensional extension has been shown capable of reconstructing noisy blurred images using partial a priori information about the true image and the point spread function in a variety of situations by means of simulations. This paper analyses the behaviour of the algorithm by investigating the static properties of the cost function and the dynamic convergence of the parameter estimates. The theoretical results are supported with computer simulations. Copyright (c) 2006 John Wiley & Sons, Ltd
Türkiye Uludağ’dan yeni bir Cota türü
No full textCota hamzaoglui U.Ozbek & Vural (Asteraceae, Anthemideae) is described as a new species from Uludag in the Bursa province of Turkey. Information given on the new species includes a Latin diagnosis, taxonomic description, line drawing, and several photographs, as well as comments on the species' geographical distribution, including a map, and its affinity to Cota oxylepis Boiss. and C. fulvida (Grierson) Holub.Cota hamzaoglui U.Özbek & Vural (Asteraceae, Anthemideae) Uludağ’dan (Bursa) yeni bir tür olarak betimlendi. Yeni türün latince ayırt edici özellikleri, taksonomik betimi, çizimi, coğrafi k yayılışı ve Cota oxylepis Boiss. ve C. fulvida (Grierson) Holub’ya yakınlığı hakkında bazı yorumlar yapıldı
Recursive blind image deconvolution via dispersion minimization
No full textThis paper presents an adaptive autoregressive (AR) approach to the blind image deconvolution problem which has several advantages over standard adaptive FIR filters. There is no need to figure out the optimum filter support when using an AR deconvolution filter because it is the same as the support of the blur. Thus there is no distortion introduced by the finite support of the FIR filter. While an FIR filter provides an approximate inverse to the blur at convergence, the AR filter converges to an approximation of the blur itself. Hence, the method can be used for blur identification. Simulations suggest that convergence of the adaptive AR filter coefficients occur rapidly and the improvement in signal-to-noise ratios are higher than in the FIR case for a given blur (and with the same step-size for the adaptive algorithms). When the adaptive AR method is derived naively to minimize the dispersion, it requires a recursion within a recursion which is computationally complex. We propose a simplification that removes the inner recursion, and prove conditions under which this simplification is valid when dealing with binary images. Simulations are used to show that the method may also be applied to certain multi-valued images as well. Copyright (c) 2005 John Wiley & Sons, Ltd
Blind image deconvolution via dispersion minimization
No full textIn linear image restoration, the point spread function of the degrading system is assumed known even though this information is usually not available in real applications. As a result, both blur identification and image restoration must be performed from the observed noisy blurred image. This paper presents a computationally simple iterative blind image deconvolution method which is based on non-linear adaptive filtering. The new method is applicable to minimum as well as mixed phase blurs. The noisy blurred image is assumed to be the output of a two-dimensional linear shift-invariant system with an unknown point spread function contaminated by an additive noise. The method passes the noisy blurred image through a two-dimensional finite impulse response adaptive filter whose parameters are updated by minimizing the dispersion. When convergence occurs, the adaptive filter provides an approximate inverse of the point spread function. Moreover, its output is an estimate of the unobserved true image. Experimental results are provided. (c) 2005 Elsevier Inc. All rights reserved
A new combination in Descurainia (Brassicaceae) from Turkey
No full textDescurainia sophia (L.) Webb ex Prantl subsp. bartschii (O.E. Schulz) C. Vural comb. & stat. nov., previously regarded as a species, is proposed based on the morphological and pollen characteristics. A detailed description is given on the basis of new material from the type locality. The taxon is endemic to central Anatolia, Turkey. A key to the Turkish subspecies of Descurainia sophia is provided
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