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Induction and Characterization of Embryogenic Callus in Cotyledons Leaves of Tabebuia roseo-alba

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Journal of Agricultural Science and Technology(B) 2012年第8期2卷 950-955页

作者： Jorge Marcelo Padovani Porto Patricia Duarte de Oliveira Paiva Renato Paiva Eduardo Alves departament of Biology Federal University of Lavras Lavras 37200-000 Brazil departament of Agriculture Federal University of Lavras Lavras 37200-000 Brazil departament of Plant Pathology Federal University of Lavras Lavras 37200-000 Brazil

Seeds from Tabebuia roseo-alba lose viability very fast. Moreover, the seed germination rate is very low, reaching approximately 40%. This study aimed at the in vitro induction of embryogenic callus. This technology allows subsequent plant regeneration as an alternative for the production of T. roseo-alba seedlings. Seeds were germinated in vitro and after 20 days, cotyledonary leaves, hypocotyls and root segments excised from these seedlings were used as explants. They were inoculated on MS medium supplemented with sucrose (30 g/L), agar (5.0 g/L) and different auxins. The effect of 2,4-D, picloram and NAA at concentrations 0.0, 0.5, 1.0, 2.0 and 4.0 mg/L was evaluated. For the analysis of callus with embryogenic characteristics, ultra-structural study by scanning electron microscopy and cytochemical test with carmine were performed. The results showed that the culture medium supplemented with 4 mg/L NAA presented induction of callus with embryogenic characteristics in all explants used, with cotyledonary leaves showing the highest percentage (70% of explants with embryogenic characteristics). The use of 2, 4-D and picloram was efficient for callus formation in different explants, but no embryogenic characteristics were observed. From the ultra-structural analysis of callus with embryogenic characteristics, it was found that cells from different explant sources had isodiametric format. This format is similar to somatic embryos in globular stage. The cytochemical analysis confirmed the presence of pro-embryogenic cells in callus mass. Callus induced from cotyledonary leaves presented 46% positive reaction to carmine acetic.

关键词：胚性愈伤组织体外诱导子叶体细胞胚胎扫描电子显微镜 MS培养基发生特性表征

具有全局中心的平面多项式Hamilton系统

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中国科学：数学 2022年第6期52卷 617-628页

作者：何鸿锦 Jaume Llibre 肖冬梅上海交通大学数学科学学院上海200240 departament de Matemátiques Universitat Autònoma de BarcelonaBarcelona 08193Spain

本文给出平面多项式Hamilton系统具有全局中心的充要条件,这刻画出整个实平面有叶层结构,即它被该系统对应的多项式Hamilton函数的水平集(即实代数曲线)分层,而每一层对应的实代数曲线都是卵形线(即紧闭分枝).进一步地,本文证明,对于任... 详细信息

本文给出平面多项式Hamilton系统具有全局中心的充要条件,这刻画出整个实平面有叶层结构,即它被该系统对应的多项式Hamilton函数的水平集(即实代数曲线)分层,而每一层对应的实代数曲线都是卵形线(即紧闭分枝).进一步地,本文证明,对于任意正整数n和任意一种类型中心(即线性型、幂零型和退化型),都存在2n+1次平面多项式Hamilton系统使其具有该类型的全局中心,而2n次平面多项式Hamilton系统没有全局中心.作为特殊情形,本文也给出平面三次多项式Hamilton系统具有退化型中心的充要条件.

关键词：平面多项式 Hamilton系统全局中心实代数曲线卵形线

Optimal Synergic Deep Learning for COVID-19 Classification Using Chest X-Ray Images

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Computers, Materials & Continua 2023年第6期75卷 5255-5270页

作者： JoséEscorcia-Gutierrez Margarita Gamarra Roosvel Soto-Diaz Safa Alsafari Ayman Yafoz Romany F.Mansour departament of Computational Science and Electronic Universidad de la CostaCUCBarranquilla080002Colombia Biomedical Engineering Program Universidad Simón BolívarBarranquilla080002Colombia Department of Computer Science and AI Faculty of Computer Science and EngineeringUniversity of JeddahJeddahSaudi Arabia Department of Information Systems Faculty of Computing and Information TechnologyKing Abdulaziz UniversityJeddahSaudi Arabia Department of Mathematics Faculty of ScienceNew Valley UniversityEl-Kharga72511Egypt

A chest radiology scan can significantly aid the early diagnosis and management of COVID-19 since the virus attacks the *** X-ray(CXR)gained much interest after the COVID-19 outbreak thanks to its rapid imaging time,widespread availability,low cost,and *** radiological investigations,computer-aided diagnostic tools are implemented to reduce intra-and inter-observer *** lately industrialized Artificial Intelligence(AI)algorithms and radiological techniques to diagnose and classify disease is *** current study develops an automatic identification and classification model for CXR pictures using Gaussian Fil-tering based Optimized Synergic Deep Learning using Remora Optimization Algorithm(GF-OSDL-ROA).This method is inclusive of preprocessing and classification based on *** data is preprocessed using Gaussian filtering(GF)to remove any extraneous noise from the image’s ***,the OSDL model is applied to classify the CXRs under different severity levels based on CXR *** learning rate of OSDL is optimized with the help of ROA for COVID-19 diagnosis showing the novelty of the *** model,applied in this study,was validated using the COVID-19 *** experiments were conducted upon the proposed OSDL model,which achieved a classification accuracy of 99.83%,while the current Convolutional Neural Network achieved less classification accuracy,i.e.,98.14%.

关键词： Artificial intelligence chest X-ray COVID-19 optimized synergic deep learning preprocessing public health

Positive-Definite Operator-Valued Kernels and Integral Representations

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Applied Mathematics 2012年第12期3卷 1990-1999页

作者： L. Lemnete-Ninulescu departament of Mathematics Politechnica University of Bucharest Bucharest Romania

A truncated trigonometric, operator-valued moment problem in section 3 of this note is solved. Let be a finite sequence of bounded operators, with arbitrary, acting on a finite dimensional Hilbert space H. A necessary and sufficient condition on the positivity of an operator kernel for the existence of an atomic, positive, operator-valued measure , with the property that for every with , the moment of coincides with the term of the sequence, is given. The connection between some positive definite operator-valued kernels and the Riesz-Herglotz integral representation of the analytic on the unit disc, operator-valued functions with positive real part in the class of operators in Section 4 of the note is studied.

关键词： Unitary-Operator Self-Adjoint Operator Joint Spectral Measure of a Commuting Tuple of Operators Spectral Projector Complex Moments Analytic Vectorial Functions

Influence of the Molecular Weight on PVA/GO Composite Membranes for Fuel Cell Applications

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Journal of Renewable Materials 2020年第9期8卷 1171-1180页

作者： C.González-Guisasola O.Gil-Castell R.Teruel-Juanes A.Ribes-Greus Instituto de Tecnología de Materiales(ITM) Universitat Politècnica de ValènciaValencia46022Spain departament d’Enginyeria Química Universitat de ValènciaBurjassot46100Spain

Composite polymer electrolyte membranes were prepared with poly(vinyl alcohol)(PVA).Two different molecular weight(Mw),67·103 and 130·103 g·mol−1 were selected,cross-linked with sulfosuccinic acid(SSA)and doped graphene oxide(GO).The effects on the membranes obtained from these polymers were characterized in order to evaluate the fuel cell *** microscopy showed a proper nanoparticle distribution in the polymer *** chemical structure was evaluated by Fourier transform infrared *** absence of a crystalline structure and the enhancement on the thermal stability with the addition of 1%of GO was demonstrated by thermal *** transference number and protonic conductivity were correlated to the performance of a hydrogen fuel ***,a power increase in the composite membranes with lower molecular weight was *** polymer chains may improve protonic conductivity and consequently the fuel cell performance.

关键词： Fuel cell graphene oxide polarization poly(vinyl alcohol) polyelectrolyte

A Feature Selection Strategy to Optimize Retinal Vasculature Segmentation

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Computers, Materials & Continua 2022年第2期70卷 2971-2989页

作者： Jose Escorcia-Gutierrez Jordina Torrents-Barrena Margarita Gamarra Natasha Madera Pedro Romero-Aroca Aida Valls Domenec Puig Electronic and Telecommunications Engineering Program Universidad Autónoma del CaribeBarranquilla080001Colombia Department of Computational Science and Electronic Universidad de la CostaCUCBarranquilla080001Colombia Ophthalmology Service Universitari Hospital Sant JoanInstitut de Investigacio Sanitaria Pere VirgiliReus43201Spain departament d’Enginyeria Informàtica i Matemàtiques Escola Tècnica Superior d’EnginyeriaUniversitat Rovira i VirgiliTarragona43007Spain

Diabetic retinopathy (DR) is a complication of diabetesmellitus thatappears in the retina. Clinitians use retina images to detect DR pathologicalsigns related to the occlusion of tiny blood vessels. Such occlusion brings adegenerative cycle between the breaking off and the new generation of thinnerand weaker blood vessels. This research aims to develop a suitable retinalvasculature segmentation method for improving retinal screening proceduresby means of computer-aided diagnosis systems. The blood vessel segmentationmethodology relies on an effective feature selection based on SequentialForward Selection, using the error rate of a decision tree classifier in theevaluation function. Subsequently, the classification process is performed bythree alternative approaches: artificial neural networks, decision trees andsupport vector machines. The proposed methodology is validated on threepublicly accessible datasets and a private one provided by Hospital Sant Joanof Reus. In all cases we obtain an average accuracy above 96% with a sensitivityof 72% in the blood vessel segmentation process. Compared with the state-ofthe-art, our approach achieves the same performance as other methods thatneed more computational *** method significantly reduces the numberof features used in the segmentation process from 20 to 5 dimensions. Theimplementation of the three classifiers confirmed that the five selected featureshave a good effectiveness, independently of the classification algorithm.

关键词： Diabetic retinopathy artificial neural networks decision trees support vector machines feature selection retinal vasculature segmentation

Small-scale edaphic heterogeneity as a floristic-structural complexity driver in Seasonally Dry Tropical Forests tree communities

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Journal of Forestry Research 2020年第6期31卷 2347-2357页

作者： Cle´ber Rodrigo de Souza Jean Daniel Morel Alisson Borges Miranda Santos Wilder Bento da Silva Vinı´cius Andrade Maia Polyanne Aparecida Coelho Vanessa Leite Rezende Rubens Manoel dos Santos Forest Sciences departament Federal University of LavrasCx.P.3037Lavras 37200-000Brazil Biology Department Federal University of LavrasCx.P.3037Lavras 37200-000Brazil

Our work aimed to test the hypothesis that soil microscale heterogeneity act as a community ecological driver,increasing diversity and promoting structural shifts on the Seasonally Dry Tropical Forest(SDTF)tree *** evaluated the relationship between microscale edaphic variations and floristic–structural patterns of tree communities in a SDTF fragment located in the southern end of the Brazilian Caatinga *** and soil data were obtained through 27 sample units of 400 m2(20 m 920 m),within each one we measured and identified at species level all arboreal individuals with Circumference at the Breast Height greater or equal to 10 cm,and also collected the soil *** the data we evaluated soil variation influence on the tree community structural and floristic patterns trough generalized linear *** explained the small-scale structural and floristic variations,contributing significantly to biomass,sprouting and to floristic relationships between sample *** was also observed a possible relation of the result with the Caatinga domain biogeographic history,due the presence of Sedimentary Caatinga species,which are not expected for the study *** plays an important role in driving small-scale complexity and diversity of SDTF,but we also suggest that Caatinga biogeographic events have influence on the high heterogeneity patterns.

关键词： Caatinga domain Edaphic variables Sprouting Sedimentary Caatinga

Periodic Orbits for Some Systems of Delay Differential Equations

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Acta Mathematica Sinica,English Series 2008年第2期24卷 267-274页

作者： Jaume LLIBRE Alexandrina-Alina TAR■A departament de Matemàtiques Universitat Autònoma de Barcelona 08193 Bellaterra Barcelona Spain Department of Applied Mathematics Babe■-Bolyai University1 Kogalniceanu str. 400084 Cluj-Napoca Cluj Romania

We provide sufficient conditions for the existence of periodic orbits of some systems of delay differential equations with a unique delay. We extend Kaplan-Yorke＇s method for finding periodic orbits from a delay diff... 详细信息

关键词： delay differential system periodic orbit

Public places contamination in Tirana from dogs intestinal geohelminths

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Journal of Coastal Life Medicine 2016年第9期4卷 714-717页

作者： Violeta Zanaj Dhimitër Rrapti Milidin Bakalli departament of Medicine Aleksander Moisiu University of DurresDurresAlbania departament of Medicine Veterinare Agricultural University of TiranaTiranaAlbania

Objective:To assess the prevalence of infestation of stray dogs that attend public areas of Tirana by geohelminths zoonotic:Toxocara canis(***),Ancylostomatids and Trichuris spp.,and indirectly to assess the level of environment contamination by invasive exogenous stages of these ***:A total of 240 fecal samples was collected from stray dogs in public three urban areas of *** samples were analyzed by using the centrifugation-flotation ***:Result showed that 54.58%of the dogs were infested from ***,Ancylostomatids(Ancylostoma *** Uncinaria spp.)and Trichuris *** infested dogs from Ancylostomatids were 37(15.41%),from *** were 47(19.58%)and from Trichuris *** 47(19.58%).Conclusions:Tirana public places are contaminated by exogenous stages of invasive intestinal dog’s geohelminths all through the *** the contamination level is higher during the spring and autumn and the parks with trees and grass are more polluted than the bare *** these environments have become a permanent risk factor of infection from parasitic zoonoses for the humans and animals that frequent those *** is the duty of local authorities who takes care of legislation compilation,to prevent the public areas to become fecalized from dogs and to implement a plan with different actions to minimize the number of stray dogs.

关键词： Geohelminths zoonotic Stray dogs Prevalence Contamination Infestation