PLANT LEAF IDENTIFICATION BASED ON VOLUMETRIC FRACTAL DIMENSION

Texture is an important visual attribute used to describe the pixel organization in an image. As well as it being easily identified by humans, its analysis process demands a high level of sophistication and computer complexity. This paper presents a novel approach for texture analysis, based on analyzing the complexity of the surface generated from a texture, in order to describe and characterize it. The proposed method produces a texture signature which is able to efficiently characterize different texture classes. The paper also illustrates a novel method performance on an experiment using texture images of leaves. Leaf identification is a difficult and complex task due to the nature of plants, which presents a huge pattern variation. The high classification rate yielded shows the potential of the method, improving on traditional texture techniques, such as Gabor filters and Fourier analysis.

Plant Leaf Identification Using Gabor Wavelets

This article presents a novel method of plant classification using Gabor wavelet filters to extract texture filters in a foliar surface. The aim of this promising method is to add to the results obtained by other leaf attributes (such as shape, contour, color, among others), increasing, therefore, the percentage of classification of plant species. To corroborate the efficiency of the technique, an experiment using 20 species from Brazilian flora was done and discussed. The results are also compared with texture Fourier descriptors and cooccurrence matrices. (C) 2009 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 19, 236-243, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ima.20201

The effects of temperature on the molecular orientation of zinc phthalocyanine films

Phthalocyanine compounds have been widely investigated as candidate materials for technological applications, which is mainly due to their thermal stability and possibility of processing in the form of thin films. In most applications, the controlled growth of thin films with high crystalline quality is essential. In this study, zinc phthalocyanine (ZnPc) thin films were prepared by evaporation on glass and Au-coated glass substrates with subsequent annealing at different temperatures in ambient atmosphere. The morphological and structural features of 80 nm thick zinc phthalocyanine films were investigated, evidencing an alpha -> beta phase transformation after annealing the films at 200 A degrees C, as indicated by UV-Vis spectroscopy and FTIR analyses. A better uniformity of the annealed films was also evidenced via AFM analysis, which may be of importance for applications where film homogeneity and excellent optical quality are required.

ON CLOSED GEODESICS IN THE LEAF SPACE OF SINGULAR RIEMANNIAN FOLIATIONS

In this paper we prove the existence of closed geodesics in the leaf space of some classes of singular Riemannian foliations (s.r.f.), namely s.r.fs. that admit sections or have no horizontal conjugate points. We also investigate the shortening process with respect to Riemannian foliations.

Pineapple Leaf Fibers for Composites and Cellulose

Pineapple leaf fiber (PALF) which is rich in cellulose, abundantly available, relatively inexpensive, low density, nonabrasive nature, high filling level possible, low energy consumption, high specific properties, biodegradability and has the potential for polymer reinforcement. The utilization of pineapple leaf fiber (PALF) as reinforcements in thermoplastic and thermosetting resins in micro and nano form for developing low cost and lightweight composites is an emerging field of research in polymer science and technology. In this paper we examines the industrial applicabiliy of PALF, mainly for production of composite materials and special papers, chemical feedstocks (bromelin enzyme) and fabrics.

INVASIVE AQUATIC INVASION: THE SPREAD OF VARIABLE LEAF MILFOIL IN MAINE

http://digitalcommons.colby.edu/atlasofmaine2009/1033/thumbnail.jpg

Use of microprojectile bombardment in transient expression assays to analyze protochlorophyllide reductase gene expression in greening maize seedling leaf cells

In young cells of leaf meristems the progenitors of chloroplasts are small organelles known as proplastids, which divide and differentiate into chloroplasts. However, in the absence of light, proplastids undergo a different sequence of development and become etioplasts. When light is supplied to etiolated plants during the "greening" process, etioplasts differentiate into chloroplasts containing chlorophyll. An important light dependent step in chlorophyll biosynthesis is the photoreduction of protochlorophyllide to chlorophyllide by the NADPH:protochlorophyllide reductase (PCR) enzyme. This enzyme is present at high activity only in etiolated tissue and during early stages of light-induced chlorophyll synthesis. The enzyme and its corresponding mRNAs decrease dramatically with prolonged exposure to light. We have investigated the light-dependent transcriptional regulation of a PCR gene in greening maize leaf cells using a transient expression assay based on microprojectile bombardment. The promoter region was isolated and cloned into a ?-glucuronidase (GUS) reporter gene expression plasmid. We have used this chimeric plasmid in tungsten particle bombardment of both etiolated and greening maize seedling leaves to determine whether the cloned promoter region contains regulatory sequences that control light-responsive PCR gene expression.

Invasive Aquatic Invasion: The Spread of Variable Leaf Milfoil in Maine

Variable leaf milfoil, Myriophyllum heterophyllum, has been present in Maine since 1970. We created an analysis area including seventeen infestation sites and all bodies of water within a forty mile buffer. We also eliminated all water locations with a size less than 7,101 km2, the size of the smallest infestation site, Shagg Pond. Within those specifications we randomly selected seventeen un-infested bodies of water and used them as our uncontaminated sample. We looked for relationships between presence and number of boat launches, and proximity to a populated area. Using the Mann-Whitney test, we compared the sample size of non-infested lakes to the infested lakes. We found there was no significant difference in all three variables on the infestation of variable leaf milfoil.

Caracterização funcional de dois cDNAs de cana-de- açúcar : PKCI e SHAGGY

Flowering is controlled by several environmental and endogenous factors, usually associated with a complex network of metabolic mechanisms. The gene characterization in Arabidopsis model has provided much information about the genetic and molecular mechanisms that control flowering process. Some of these genes had been found in rice and maize. However, in sugarcane this processe is not well known. It is known that early flowering may reduce its production up to 60% at northeast conditions. Considering the impact of early flowering in sugarcane production, the aim of this work was to make the gene characterization of two cDNAs previously identified in subtractive cDNA libraries: scPKCI and scSHAGGY. The in silico analysis showed that these two cDNAs presented both their sequence and functional catalytic domains conserved. The results of transgenic plants containing the overexpression of the gene cassette scPKCI in sense orientation showed that this construction had a negative influence on the plant development as it was observed a decrease in plant height and leaf size. For the scPKCI overexpression in antisense orientation it was observed change in the number of branches from T1 transgenic plants, whereas transgenic T2 plants showed slow development during germination and initial stages of development. The other cDNA analyzed had homology to SHAGGY protein. The overexpression construct in sense orientation did not shown any effect on development. The only difference observed it was an increase in stigma structure. These results allowed us to propose a model how these two genes may be interact and affect floweringdevelopment.

Leaf anatomy of rubber-tree clones

A seringueira é uma planta de fácil reconhecimento por ser lenhosa, de porte mediano a grande, que apresenta um padrão característico de desfolha e reenfolhamento e, sobretudo, pela produção de látex. O objetivo do trabalho foi efetuar um estudo anatômico e morfológico foliar, comparando os clones RRIM 600 e GT 1 de seringueira &91;Hevea brasiliensis (Wild. ex Adr. de Juss.) Muell.- Arg&93;, desenvolvidos sob as mesmas condições edáficas e climáticas, para obtenção de informações que possam fornecer subsídios para correlações com dados fisiológicos e também diferenciar os clones em relação ao conteúdo de fibras, espessamento de tecidos do parênquima paliçádico e do parênquima lacunoso, caracterização anatômica do pecíolo, número e tamanho de estômatos e fornecer dados referentes a morfologia foliolar. Foram realizadas secções transversais na região do mesófilo, nervura central e pecíolo, seguindo-se os métodos usuais de preparação de lâminas permanentes. Foram realizadas análises biométricas de extensões de tecidos dos parênquimas paliçádico e lacunoso e contagem do número de células do parênquima lacunoso. Paralelamente foram realizadas análises biométricas para aferições de estômatos. Não houve diferenças para a altura das células epidérmicas, altura e número de camadas do parênquima lacunoso e para o comprimento e para a maior largura do limbo foliolar. Porém houve variação para a espessura das células do parênquima paliçádico, sendo que GT 1 apresentou maior espessura em relação a RRIM 600. GT1 apresentou maior número de estômatos em relação a RRIM 600, porém com menor tamanho. GT1 apresentou maior diâmetro da nervura central da folha e do pecíolo e maior quantidade de fibras de esclerênquima que RRIM 600.

Orientation and external morphology of burrows of the mangrove crab Ucides cordatus (Crustacea: Brachyura: Ucididae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Acute lethal and sublethal effects of neem leaf extract on the neotropical freshwater fish Prochilodus lineatus

The aim of this study was to determine the toxicity of the aqueous extract of neem leaves, a product extensively used in fish-farms as alternative for the control of fish parasites and fish fry predators, for the neotropical fish Prochilodus lineatus. The 24 It LC(50) of neem leaf extract for juveniles P lineatus was estimated as 4.8 g L(-1); the fish were then exposed for 24 h to 2.5, 5.0 and 7.5 g L(-1) or only clean water (control). Plasma glucose levels were higher in fish exposed to 2.5 g L(-1) and 5.0 g L(-1) neem extract, relative to control, indicating a typical stress response. Neem extract did not interfere with the osmoregulating capacity of the fish, as their plasma sodium, chloride, total protein and osmolarity did not change. The presence of the biopesticide interfered with the antioxidant defense system of P. lineatus, as there was a decrease in liver catalase activity at all neem concentrations and the detoxifying enzyme glutathione-S-transferase was activated in fish exposed to 5.0 g L(-1). Fish exposed to all neem extract concentrations exhibited damaged gill and kidney tissue. These results indicate that although neem extract is less toxic to P. lineatus than other synthetic insecticides used in fish-farming it does cause functional and morphological changes in this fish species. (c) 2006 Elsevier B.V. All rights reserved.

Cryptococcus haglerorum, sp nov., an anamorphic basidiomycetous yeast isolated from nests of the leaf-cutting ant Atta sexdens

A yeast strain (CBS 8902) was isolated from the nest of a leaf-cutting ant and was shown to be related to Cryptococcus humicola. Sequencing of the D1/D2 region of the 26S ribosomal DNA and physiological characterization revealed a separate taxonomic position. A novel species named Cryptococcus haglerorum is proposed to accommodate strain CBS 8902 that assimilates n-hexadecane and several benzene compounds. Physiological characteristics distinguishing the novel species from some other members of the C. humicola complex are presented. The phylogenetic relationship of these strains to species of the genus Trichosporon Behrend is discussed.

Metabolism of plant polysaccharides by Leucoagaricus gongylophorus, the symbiotic fungus of the leaf-cutting ant Atta sexdens L.

Atta sexdens L, ante feed on the Fungus they cultivate on cut leaves inside their nests. The fungus, Leucoagaricus gongylophorus, metabolizes plant polysaccharides, such as xylan, starch, pectin, and cellulose, mediating assimilation of these compounds lay the ants, This metabolic integration may be an important part of the ant-fungus symbiosis, and it involves primarily xylan and starch, both of which support rapid fungal growth. Cellulose seems to be less important for symbiont nutrition, since it is poorly degraded and assimilated by the fungus. Pectin is rapidly degraded but slowly assimilated by L. gongylophorus, and its degradation may occur so that the fungus can more easily access other polysaccharides in the leaves.