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22. Some fixed point theorems in logarithmic convex structures
- Creator:
- Moazzen, Alireza, Cho, Yoel-Je, Park, Choonkil, and Eshaghi Gordji, Madjid
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- fixed point, logarithmic convex structure, and convex metric space
- Language:
- English
- Description:
- In this paper, we introduce the concept of a logarithmic convex structure. Let X be a set and D : X × X → [1, ∞) a function satisfying the following conditions: (i) For all x, y ∈ X, D(x, y) ≥ 1 and D(x, y) = 1 if and only if x = y. (ii) For all x, y ∈ X, D(x, y) = D(y, x). (iii) For all x, y, z ∈ X, D(x, y) ≤ D(x, z)D(z, y). (iv) For all x, y, z ∈ X, z ≠ x, y and λ ∈ (0, 1), D(z, W(x, y, λ)) ≤ D λ (x, z)D 1−λ (y, z), D(x, y) = D(x, W(x, y, λ))D(y, W(x, y, λ)), where W : X ×X ×[0, 1] → X is a continuous mapping. We name this the logarithmic convex structure. In this work we prove some fixed point theorems in the logarithmic convex structure.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
23. The occurrence of metacercariae of Petasiger (Digenea: Echinostomatidae) in an unusual site, within the lateral line scales of cyprinid fishes
- Creator:
- Kálmán Molnár, Gibson, David I, Cech, Gábor, Papp, Melitta, Deák-Paulus, Petra, Juhász, Lajos, Tóth, Norbert, and Székely, Csaba
- Format:
- electronic, počítač, and online zdroj
- Type:
- model:article and TEXT
- Subject:
- kaprovití, Cyprinidae, Balaton (Maďarsko : jezero), Balaton Lake (Hungary), metacercaria, molecular identification, Kis-Balaton Reservoir, 2, and 59
- Language:
- English
- Description:
- During a regular veterinary inspection of fishes from Lake Balaton, Hungary, echinostomatid metacercariae (Digenea), with collar spines characteristic of species of the genera Petasiger Dietz, 1909 and Paryphostomum Dietz, 1909, were found in the lateral line scales of a roach Rutilus rutilus (Linnaeus), an apparently unique site. In a subsequent examination of 586 fishes from 20 different species, similar infections were found in 11 species. The infection was virtually restricted to the lateral line scales, other scales being infected only incidentally. These encysted metacercariae had 27 collar spines, including eight larger angle spines and 19 smaller dorsal spines arranged in two rows. Two types of metacercarial cyst were found. One type had a cyst diameter of 138-171 µm × 105-120 µm and three central dorsal spines that were larger than the remainder and tended to resemble the angle spines. The second type of metacercarial cyst had a diameter of 128-157 µm × 105-115 µm and all 19 dorsal spines of the metacercaria were of a similar size. ITS sequences of the second type of metacercaria exhibited a 100% similarity to sequences of two adult Petasiger phalacrocoracis (Yamaguti, 1939) specimens collected from the gut of Phalacrocorax carbo (Linnaeus) in Hungary and to P. phalacrocoracis deposited in the GenBank database. Sequences obtained from two metacercariae of the first type showed a 2.8-2.9 % difference from sequences of the second type of metacercaria and from those of adult specimens of P. phalacrocoracis from cormorants. Based on these results, the second type metacercaria is considered to be a larval stage of P. phalacrocoracis, but the identity of the first type is uncertain. The unusual location of these metacercariae in the lateral line scales is discussed in relation to their transmission., Kálmán Molnár, David I. Gibson, Gábor Cech, Melitta Papp, Petra Deák-Paulus, Lajos Juhász, Norbert Tóth, Csaba Székely., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
24. The taxonomic identity and phylogenetic relationships of Cercaria pugnax and C. helvetica XII (Digenea: Lecithodendriidae) based on morphological and molecular data
- Creator:
- Kudlai, Olena, Stunžėnas, Virmantas, and Tkach, Vasyl
- Format:
- electronic, počítač, and online zdroj
- Type:
- model:article and TEXT
- Subject:
- morfologie (biologie), fylogeneze, morphology (biology), phylogeny, Paralecithodendrium, Lecithodendrium, xiphidiocercaria, rDNA sequences, 2, and 59
- Language:
- English
- Description:
- The present study analysed the taxonomic status and phylogenetic relationships of two species of xiphidiocercariae of the ʻmicrocotylaeʼ group, Cercaria pugnax La Valette St. George, 1855, from Viviparus viviparus (Linnaeus) in the Ukraine and Cercaria helvetica XII Dubois, 1928 from Bithynia tentaculata (Linnaeus) in Lithuania. Molecular phylogenetic analyses based on sequences of the ITS2 region and partial 28S gene of the nuclear rDNA revealed that both these xiphidiocercariae belong to the Lecithodendriidae Lühe, 1901 and represent larval stages of lecithodendriids parasitic in bats. Cercaria helvetica XII clustered with the typical representatives of the genus Lecithodendrium Looss, 1896, being very close, but not identical, to Lecithodendrium linstowi Dollfus, 1931. Sequences of C. pugnax matched exactly the sequences of adult Paralecithodendrium chilostomum (Mehlis, 1831). Morphological descriptions of the cercariae are included; these represent the first report of non-virgulate xiphidiocercariae belonging to the family Lecithodendriidae. Until now, the presence of glandular virgula organ in the region of the oral sucker was considered a robust synapomorphy for the Lecithodendriidae and several closely related families. Our results have shown that the relative importance of this character is in need of a re-assessment., Olena Kudlai, Virmantas Stunžėnas, Vasyl Tkach., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
25. Two new species of Urocleidoides Mizelle et Price, 1964 (Monogenoidea) from the gill lamellae of profundulids and poeciliids from Central America and southern Mexico
- Creator:
- Mendoza-Franco, Edgar F, Caspeta-Mandujano, Juan Manuel, Salgado-Maldonado, Guillermo, and Matamoros, Wilfredo Antonio
- Format:
- electronic, počítač, and online zdroj
- Type:
- model:article and TEXT
- Subject:
- parazitologie, parasitology, Guerrero (Mexiko : stát), Oaxaca de Juárez (Mexiko), Chiapas (Mexiko : stát), Guatemala, Honduras, Salvador, Panama, Guerrero (Mexico : state), Oaxaca (Mexico : State), Chiapas (Mexico : state), Guatemala City (Guatemala), Salvador (Brazil), Panama (Panama), Dactylogyridae, Profundulus, Pseudoxiphophorus, Poeciliopsis, Xiphophorus, 2, and 59
- Language:
- English
- Description:
- During investigations of gill ectoparasites (Platyhelminthes) parasitising freshwater fish from Central America (Guatemala, Honduras, El Salvador and Panama) and southeastern Mexico (Guerrero, Oaxaca and Chiapas), the following dactylogyrid monogenoidean were found: Urocleidoides simonae sp. n. from Profundulus punctatus (Günther) (type host), Profundulus balsanus Ahl, Profundulus guatemalensis (Günther), Profundulus kreiseri Matamoros, Shaefer, Hernández et Chakrabarty, Profundulus labialis (Günther), Profundulus oaxacae (Meek), Profundulus sp. 1 and Profundulus sp. 2 (all Profundulidae); Urocleidoides vaginoclaustroides sp. n. from Pseudoxiphophorus bimaculata (Heckel) (type host) and Poeciliopsis retropinna (Regan) (both Poeciliidae); and Urocleidoides vaginoclaustrum Jogunoori, Kritsky et Venkatanarasaiah, 2004 from P. labialis, Profundulus portillorum Matamoros et Shaefer and Xiphophorus hellerii Heckel (Poeciliidae). Urocleidoides simonae sp. n. differs from all other congeneric species in having anchors with well-differentiated roots, curved elongate shaft and short point. Urocleidoides vaginoclaustroides sp. n. most closely resembles U. vaginoclaustrum, but differs from this species mainly in the shape of its anchors (i.e. evenly curved shaft and short point vs curved shaft and elongate point extending just past the tip of the superficial anchor root). The complexity of potential hosts for species of Urocleidoides and their effect on its distribution on profundulid and poeciliid fishes are briefly discussed., Edgar F. Mendoza-Franco, Juan Manuel Caspeta-Mandujano, Guillermo Salgado-Maldonado, Wilfredo Antonio Matamoros., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
26. Ultrastructure and phylogeny of Glugea nagelia sp. n. (Microsporidia: Glugeidae), infecting the intestinal wall of the yellowfin hind, Cephalopholis hemistiktos (Actinopterygii: Serranidae), from the Red Sea
- Creator:
- Abdel-Baki, Abdel-Azeem S, Al-Quraishy, Saleh, Rocha, Sónia, Dkhil, Mohamed A, Casal, Graça, and Azevedo, Carlos
- Format:
- electronic, počítač, and online zdroj
- Type:
- model:article and TEXT
- Subject:
- parazitické organismy, parasitic organisms, fish parasite, microsporidian, fine structure, rRNA genes, 2, and 59
- Language:
- English
- Description:
- A new microsporidian species of the genus Glugea Thélohan, 1891 parasitising the marine teleost fish Cephalopholis hemistiktos Rüppell, collected from the Red Sea in Saudi Arabia, is described on the basis of microscopic and molecular procedures. Spherical and whitish xenoma were observed adhering to the intestinal wall. The numerous spores contained within these xenoma, were ovoid to pyriform and measured 4.3-6.0 µm (5.1 µm) in length and 1.8-2.9 µm (2.2 µm) in width. The spore's wall was composed of two thick layers, which were thinner in the area contacting the anchoring disk. The latter appeared at the spore's anterior pole, in an eccentric position to the longitudinal axis. A lamellar polaroplast surrounded the uncoiled portion of the polar filament projected to the basal region of the spore, giving rise to 26-29 turns with winding from the base to the anterior zone of the spore. The posterior vacuole, located at the spore's posterior pole, and surrounded by the polar filament coils, was irregular and composed of light material. Molecular analysis of the rRNA genes, including the ITS region, was performed using maximum parsimony, neighbour-joining and maximum likelihood methods. The ultrastructural features observed, combined with the phylogenetic data analysed, suggest this parasite to be a new species of the genus Glugea. This is the first species of this genus to be reported from Saudi Arabia and is herein named Glugea nagelia sp. n., Abdel-Azeem S. Abdel-Baki, Saleh Al-Quraishy, Sónia Rocha, Mohamed A. Dkhil, Graça Casal, Carlos Azevedo., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
27. Wing morphometric variability of the malaria vector Anopheles (Cellia) epiroticus Linton et Harbach (Diptera: Culicidae) for the duration of the rainy season in coastal areas of Samut Songkhram, Thailand
- Creator:
- Chaiphongpachara, Tanawat and Laojun, Sedthapong
- Format:
- print, počítač, and online zdroj
- Type:
- model:article and TEXT
- Subject:
- mikroevoluce, microevolution, Thajsko, Thailand, Mosquito, coastal environment, morphological variability, geometric morphometrics, 2, and 59
- Language:
- English
- Description:
- In Thailand, Anopheles (Cellia) epiroticus Linton et Harbach (Diptera: Culicidae) is the secondary vector of human malaria along coastal regions. While there are some studies of phenotypic variability and population structure of A. epiroticus, more information on morphological variation would enhance epidemiological understanding of medically important mosquito vectors. This research examined morphological variation at three different distances from coastlines of Samut Songkhram Province, Thailand, using landmark-based geometric morphometrics. Wing shape of A. epiroticus was significantly different in the area 0.2 km away from the sea compared to areas 2 and 4 km away from the sea (p < 0.05). Phenotypic variability in wing shape is associated with distance from the sea. Morphological variations in the area closest to the sea were most pronounced, showing a relationship between A. epiroticus and the ecosystem that affects wing geometry. These results provide important information to understand morphological variation of A. epiroticus in coastal areas., Tanawat Chaiphongpachara and Sedthapong Laojun., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
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