Yapay Sinir Ağları ve K-Ortalamalar Tabanlı Büyük Veri Azaltma Algoritmasının Tasarımı ve Uygulaması

Büyük veri azaltma sürecinde karşılaşılan başlıca zorluk, veri setinin homojenliğinin ve problem uzayını temsil yeteneğinin korunmasıdır. Bu durum, büyük veri setleri üzerinde yapılan modelleme çalışmalarında hesaplama karmaşıklığının yeterince azaltılamamasına, geliştirilen modelin orijinal veri setine dayalı olarak geliştirilen modele kıyasla kararlılık ve doğruluk performansının önemli ölçüde azalmasına neden olmaktadır. Bu makale çalışmasının amacı, büyük veri setleri için kararlı ve etkili bir şekilde çalışan veri azaltma algoritması geliştirmektir. Bu amaçla, yapay sinir ağları (YSA) tabanlı problem modelleme modülü ve K-ortalamalar tabanlı veri azaltma modülünden oluşan melez bir algoritma geliştirilmiştir. Problem modelleme modülü, büyük veri seti için performans eşik değerlerini tanımlamayı sağlamaktadır. Bu sayede, orijinal veri setinin ve veri azaltma işlemi uygulanmış veri setlerinin problem uzayını temsil yetenekleri ve kararlılıkları analiz edilmektedir. K-ortalamalar modülünün görevi ise, veri uzayını K-adet kümede gruplamayı ve bu grupların her biri için küme merkezini referans alarak kademeli olarak veri (gözlem) azaltma işlemini gerçekleştirmektir. Böylelikle, K-ortalamalar modülü ile veri azaltma işlemi uygulanırken, azaltılmış veri setlerinin performansı ise YSA modülü ile test edilmekte ve performans eşik değerlerini karşılama durumu analiz edilmektedir. Geliştirilen melez veri azaltma algoritmasının performansını test etmek ve doğrulamak amacıyla UCI Machine Learning uluslararası veri havuzunda yer alan üç farklı veri seti kullanılmıştır. Deneysel çalışma sonuçları istatistiksel olarak analiz edilmiştir. Analiz sonuçlarına göre büyük veri setlerinde kararlılık ve performans kaybı yaşanmadan %30-%40 oranları arasında veri azaltma işlemi başarılı bir şekilde gerçekleştirilmiştir

Determination of anticholinesterase and antioxidant activities of methanol and water extracts of leaves and fruits of Chamaerops humilis L.

The present study was carried out to investigate the antioxidant activity of the water and methanol extracts of leaves and fruits extracts of Chamaerops humilis L. by using ABTS cation radicals and cupric reducing antioxidant capacity (CUPRAC). Anticholinesterase effect of the extracts was tested against both AChE and BChE using a microplate-reader assay based on the Ellman method. The methanol extracts of C. humilis leaves contained relatively higher content of flavonoids and total phenolics than those of fruits. All the extracts were found to have different levels of antioxidant activity in the systems tested. The leave extract showed the highest value of antioxidant activity, based on ABTS radical-scavenging activity, while the fruit water extract showed the highest value (0.53±0.50 µg/mL) of cupric reducing antioxidant activity.  Our data indicates that both methanol and water fruit extract were active for BChE inhibition (31.65 ± 0.37 and 30.19 ± 0.56%) respectively, whereas, all leave extracts did not show any activity against BChE. The present study demonstrated that the methanol and water extracts fractions of C. humilis have different responses with different antioxidant methods. Our results suggest that the C. humilis could be used as a source of antioxidant agents and may be beneficial in the AD treatment

Phytochemical profile and some biological activities of three Centaurea species from Turkey

Purpose: To characterise the phytochemical profile of whole plants of Centaurea balsamita, C. depressa and C. lycopifolia with LC-ESI-MS/MS, and as well as their antioxidant, anticholinesterase and antimicrobial activities.Methods: Organic and aqueous extracts of the three Centaurea species were evaluated for DPPH free radical, ABTS cation radical scavenging and cupric reducing antioxidant capacity (CUPRAC). Acetyland butyryl-cholinesterase enzyme inhibition abilities of the extracts using petroleum ether, acetone, methanol and water were studied to determine anticholinesterase activity, while antimicrobial activity was determined by disc diffusion method using appropriate antimicrobial standards and organisms. The phytochemical components of the methanol extracts were assessed by LC-MS/MS.Results: The methanol extract of C. balsamita exhibited much higher DPPH free and ABTS cation radicals scavenging activities (with IC50 of 62.65 ± 0.97 and 24.21 ± 0.70 mg/ml, respectively) than the other extracts. The petroleum ether extracts of the plant species exhibited moderate inhibitory activity against butyrylcholinesterase enzymes while the acetone extract of C. balsamita showed good antifungal activity against Candida albicans. Quinic acid (17513 ± 813 μg/g, 63874 ± 3066 μg/g and 108234 ± 5195 μg/g) was the major compound found in the methanol extracts of C. balsamita, C. depressa and C. Lycopifolia, respectively.Conclusion: These results indicate quinic acid is the major compound in the three plant species and that Centaurea balsamita has significant antioxidant, anticholinesterase and antimicrobial properties. Further studies to identify the compounds in the extracts responsible for the activities are required.Keywords: Centaurea, LC-ESI-MS/MS, Anticholinesterase, Antioxidant, Antimicrobia

Ecology and genomics of an important crop wild relative as a prelude to agricultural innovation

Domesticated species are impacted in unintended ways during domestication and breeding. Changes in the nature and intensity of selection impart genetic drift, reduce diversity, and increase the frequency of deleterious alleles. Such outcomes constrain our ability to expand the cultivation of crops into environments that differ from those under which domestication occurred. We address this need in chickpea, an important pulse legume, by harnessing the diversity of wild crop relatives. We document an extreme domestication-related genetic bottleneck and decipher the genetic history of wild populations. We provide evidence of ancestral adaptations for seed coat color crypsis, estimate the impact of environment on genetic structure and trait values, and demonstrate variation between wild and cultivated accessions for agronomic properties. A resource of genotyped, association mapping progeny functionally links the wild and cultivated gene pools and is an essential resource chickpea for improvement, while our methods inform collection of other wild crop progenitor species

Photochemical reactions of VIB and VIIB group metal carbonyl complexes with a chiral Schiff base

The hitherto unknown complexes, [M(CO)(4)(eta(2)-H2L)], [M = Cr; 1, Mo; 2, W; 3]; fac-[Re(CO)(3)Br(eta(2)-H2L)], 4 and [(eta(5)-C5H5)Mn(CO)Br(eta(2)-H2L)], 5 have been synthesized by the photochemical reactions of VIB and VIIB metal carbonyls [M(CO)(6)] [M = Cr, Mo, W], Re(CO)(5)Br and (eta(5)-C5H5) Mn(CO)(3) with chiral Schiff base N,N'-bis-(2-hydroxynaphthalene-1-carbaldehydene)-(1R,2R)-(-)-diaminocyclohexane (H2L) in THF and characterized by elemental analyses, FTIR, H-1-NMR and mass spectra. The spectroscopic studies show that H2L ligand is coordinated to the central metal as a bidentate ligand coordinating via its imine nitrogens (C=N) in 1-5

Synthesis and characterization of macrocyclic Cd(II) complexes

378-382Ten new Cd(II) complexes have been synthesized with Cd(ClO₄)₂.6H₂O, Cd(NO₃)₂.6H₂O in chloroform-methanol. The complexes have been characterized by elemental analysis, IR, ¹H NMR, UV-vis spectra, magnetic susceptibility, conductivity measurements and mass spectra. On the basis of the spectral studies, four-coordinated tetrahedral geometry may be assigned to these complexes

Synthesis and Characterization of Stable Hetereocyclic (Schiff Base) Divalent Tin Species and Photogeneration of Their Transition Metal Carbonyl Complexes

New stable divalent heterocyclic species [SnL1; 1, SnL2; 2] using ONNO and SNNS tetradentate Schiff bases; N,N'-bis(salicylidene)-1,2-bis(o-aminophenoxy)ethane (H2L1) and N,N'-bis(2-aminothiophenol)-1,4-bis(2-carboxaldehydephenoxy)butane (H2L2) were obtained in good yields by alcolysis of the M-N bonds of the divalent precursor Sn[N(SiMe3)2]2 by diols. They have been isolated as solids at ambient temperature and are monomeric. FT-IR, 1H and 119Sn-NMR spectra are suggestive of N ... M intramolecular coordination. Then the synthesis and characterization of the new stable mono and cis-disubstituted Sn(II) chromium and tungsten carbonyl complexes [L1Sn]M(CO)5 (M= Cr, 3; W, 4); [L2Sn]M(CO)5 (M= Cr, 5; W, 6); cis-[L1Sn]2M(CO)4 (M= Cr, 7; W, 8) and cis-[L2Sn]2M(CO)4 (M= Cr, 9; W, 10) are described. Pentacarbonyl complexes (36) were obtained in high yields by treatment of the M(CO)5THF (M= Cr, W) intermediates with the divalent species [SnL1; 1, SnL2; 2] and tetracarbonyl complexes (710) were synthesized by the photochemical reactions of [LnSn]M(CO)5 with [LnSn] (n = 1, 2). Each of the new carbonyl complexes has been characterized by IR, 1H, 13C, 119Sn-NMR spectroscopy, and mass spectrometry. The sigma donor and pi acceptor ability of the divalent tin species [SnL1, 1; SnL2, 2] as ligands in the transition metal carbonyl complexes (310) is discussed by comparing ?(CO) stretching frequencies