Length-weight relationship of 11 fish species from a tributary of the Amazon river system in northern Brazil.

The length?weight relationships (LWRs) of 11 freshwater fish for eight families (Leporinus friderici, Pterophyllum scalare, Geophagus camopiensis, Curimata incompta, Astyanax bimaculatus, Tetragonopterus chalceus, Moenkhausia lepidura, Metynnis lippincottianus, Plagioscion squamosissimus, Hemiodus unimaculatusandColomesus asellus) captured in tributary of the Amazon River system (Brazil) were investigated. These results represent the first reference on the LWRs for all 11 species in the eastern Amazon

Patterns of the parasite communities in a fish assemblage of a river in the Brazilian Amazon region.

This paper characterizes the pattern of ectoparasite and endoparasite communities in an assemblage of 35 sympatric fish from different trophic levels in a tributary from the Amazon River system, northern Brazil. In detritivorous, carnivorous, omnivorous and piscivorous hosts, the species richness consisted of 82 ectoparasites and endoparasites, but protozoan ectoparasites such as Ichthyophthirius multifiliis, Piscinoodinium pillulare and Tripartiella sp. were dominant species predominated, such that they were present in 80% of the hosts. The taxon richness was in the following order: Monogenea > Nematoda > Digenea > Crustacea > Protozoa > Acanthocephala = Cestoda > Hirudinea. Among the hosts, the highest number of parasitic associations occurred in Satanoperca jurupari, Aequidens tetramerus, Hoplerythrinus unitaeniatus, Hoplosternum littorale, Cichlasoma amazonarum, Chaetobranchus flavescens, Squaliforma emarginata, Chaetobranchopsis orbicularis and Hoplias malabaricus. A weak positive correlation between ectoparasite abundance and length of the hosts was observed. Ectoparasite communities of detritivorous, carnivorous and omnivorous hosts were similar, but these differed from the communities of piscivorous hosts. Larval endoparasite species with low host specificity were the main determinants of the parasite infracommunity structure of the fish assemblage. Fish assemblage had few species of helminth that were specialist endoparasites, while many were parasites at the larval stage, infecting intermediate and paratenic hosts. Finally, carnivorous and omnivorous hosts harbored endoparasite communities that were more heterogeneous than those of detritivorous and piscivorous hosts. This result lends supports to the notion that the feeding habits of the host species are a significant factor in determining the endoparasites fauna

La-images: A Software For Elemental Distribution Bioimaging Using La-icp-ms Data

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)The spatial distribution of chemical elements in different types of samples is an important field in several research areas such as biology, paleontology or biomedicine, among others. Elemental distribution imaging by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) is an effective technique for qualitative and quantitative imaging due to its high spatial resolution and sensitivity. By applying this technique, vast amounts of raw data are generated to obtain high-quality images, essentially making the use of specific LA-ICP-MS imaging software that can process such data absolutely mandatory. Since existing solutions are usually commercial or hard-to-use for average users, this work introduces LA-iMageS, an open-source, free-to-use multiplatform application for fast and automatic generation of high-quality elemental distribution bioimages from LA-ICP-MS data in the PerkinElmer Elan XL format, whose results can be directly exported to external applications for further analysis. A key strength of LA-iMageS is its substantial added value for users, with particular regard to the customization of the elemental distribution bioimages, which allows, among other features, the ability to change color maps, increase image resolution or toggle between 2D and 3D visualizations.8Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP, Sao Paulo, Brazil)Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq, Brasilia, Brazil)Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES, Brasilia, Brazil)Provincial Council of Ourense [INOU-16-05]national funds from FCT/MEC [UID/QUI/50006/2013, UID/Multi/04378/2013]ERDF under the PT2020 Partnership Agreement [POCI-01-0145-FEDER-007265, POCI-01-0145-FEDER-007728]Unidade de Ciencias Biomoleculares Aplicadas-UCIBIOXunta de GaliciaFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Colour segmentation of citrus fruits images for stem location

After mechanical harvesting, Cirrus fruits with long stems may cause damage on adjacent fruits during transportation and storage. A first step to solve before measuring the stem and taking the decision of cutting it or not, is the orientation of fruits. For this purpose, an image analysis method to locate the stem insertion point based on colour segmentation is proposed and evaluated. Four classes were defined for segmentation: background, peel, stem-calyx and cut stem, and a classifier based on bayesian decision rules was developed assuming that the independent variables (RGB) followed a normal distribution function, and that the classes had equal covariance matrix. The results point out an excellent performance of the classifier for the first two classes, and satisfactory for the other two. The location algorithm used information of areas and centroids to estimate the coordinates of the stem insertion point. From a total of 86 images tested, it was correctly estimated a 90,3% of times. The method resulted to be efficient for fruits without leaves appended to the stem

Distribution pattern of crustacean ectoparasites of freshwater fish from Brazil.

The purpose of this study was to use the informations relating to parasite crustaceans species that was published over the course of one century (1913 to 2013), in order to search for infestation and distribution patterns among these ectoparasites in Brazilian freshwater fish species. This search was carried out on 445 samples of 119 host fish of 27 families within the orders Characiformes, Perciformes, Clupeiformes, Mugiliformes, Osteoglossiformes, Symbranchiformes, Tetraodontiformes and Siluriformes from various regions of Brazil. We organized different host-parasite systems into matrices grouping species at different taxonomic and infestation levels and according to host parameters. Five families of parasites (Ergasilidae, Argulidae, Lernaeidae, Lernaeopodidae and Cymothoidae) distributed into 76 species of 27 genera were analyzed in the host samples, which presented dominance of Ergasilidae species, mainly from the genus Ergasilus. Some crustaceans are host and site-specific, especially in relation to fish in particular habitats and lifestyles (e.g. Perulernaea gamitanae, Anphira branchialisand Riggia paranensis), while other parasites frequently have no preference (e.g. Lernaea cyprinaceaand Braga patagonica). We found broadly similar distribution patterns for some crustacean species among the different localities, whereas other species showed well-defined geographical patterns, and these findings were discussed

Feasibility Assessment of Direct Marketing Strategies: The Case of Vegetable Farmer Clusters in Marilog, Davao City, Philippines

In the Philippines, majority of the vegetable farmers are categorized as small and are often disconnected from markets, which lessen their opportunities to sell at a profit. This study focused on the feasibility assessment of direct marketing strategies, specifically the farmers’ market and direct sales to institutional users. A random survey was conducted on 110 residents of the first district of Davao City where consumers’ willingness to shop at farmers’ markets was analyzed using Probit regression. On the other hand, case study analyses were conducted to assess the farmers’ market event in a university and the direct sales strategy to institutional user, the food service provider of a government agency. Costs and benefits of each direct marketing channel were also determined. The farmer groups PAFA and SAFE are the producers and sellers of vegetables for this research. The study revealed that majority of the respondents are willing to participate in a farmers’ market if one exists and they perceived it as a source of fresh yet affordable vegetables. Moreover, most of them believed that participating in a farmers’ market is a form of social responsibility. The institutional buyer mainly benefited through significant reduction in marketing costs. Alternatively, the farmers perceived direct marketing as opportunities for learning and maximizing economic gains through diversifying its market portfolio and securing a market for their produce. The results of the study indicate the feasibility of direct marketing strategies to be carried out by the vegetable farmer clusters, which are PAFA and SAFE

Metacercariae of Clinostomum Leidy, 1856 (Digenea: Clinostomidae) infecting freshwater fishes throughout Brazil: infection patterns, parasite?host interactions, and geographic distribution.

This review investigated information about metacercariae of Clinostomum Leidy, 1856 published over 91 years (1928 to 2019) to search for infection and geographic distribution patterns of this digenean species in freshwater fish from Brazil. The present study used 101 samples from 60 fish species of different families distributed in Characiformes, Siluriformes, Cichliformes, Gymnotiformes, Cypriniformes, Cyprinodontiformes, and Synbranchiformes. The greatest number of parasite-host associations were found for Cichliformes species of the Cichlidae family. Metacercariae of digeneans that belonged to four species of Clinostomum were found, with Clinostomum margin-atum and Clinostomum complanatum (68.7%) the dominant species, whereas 22.2% of parasites were allocated only to the genus Clinostomum. There was variation in prevalence, intensity and abundance of Clinostomum spp. in host fish, and infection sites included internal and external organs (e.g. intestine, stomach, operculum, muscle, mouth, heart, gills, body cavity, fins). There was similarity in prevalence, intensity, and abundance of Clinostomum spp. in detritivorous, omnivorous, and piscivorous host fish. Clinostomum metacercariae are distributed in the Amazon, Paraná River, São Francisco, Uruguay, Atlantic North and South, and Southeast basin systems, whereas C. marginatum and C. complanatum have distribution patterns limited to hydrographic basins of different regions. Clinostomum spp. have a cosmopolitan distribution and parasitize a diversity of host fish, and the present study constitutes the most extensive survey regarding these digeneans in fish throughout Brazil

Coherent states for compact Lie groups and their large-N limits

The first two parts of this article surveys results related to the heat-kernel coherent states for a compact Lie group K. I begin by reviewing the definition of the coherent states, their resolution of the identity, and the associated Segal-Bargmann transform. I then describe related results including connections to geometric quantization and (1+1)-dimensional Yang--Mills theory, the associated coherent states on spheres, and applications to quantum gravity. The third part of this article summarizes recent work of mine with Driver and Kemp on the large-N limit of the Segal--Bargmann transform for the unitary group U(N). A key result is the identification of the leading-order large-N behavior of the Laplacian on "trace polynomials."Comment: Submitted to the proceeding of the CIRM conference, "Coherent states and their applications: A contemporary panorama.

Location and characterization of the stem-calyx area on oranges by computer vision

Three image analysis methods were studied and evaluated to solve the problem of removing long stems attached to mechanically harvested oranges: colour segmentation based on linear discriminant analysis, contour curvature analysis, and a thinning process which involves iterating until the stem becomes a skeleton. These techniques are able to determine the presence or absence of a stem with certainty, to locate the stems from random views with more than 90% accuracy and from profile images with an accuracy ranging from 92.4% to 100% depending on the method used. Finally, determination of the length and cutting point of the stem is achieved with only 3.8% of failures. (C) 1996 Silsoe Research Institut