898 resultados para Gill
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Data from permanent parasites (juvenile trypanorhynchs and anisakids) indicated that Spanish mackerel Scomberomorus commerson from four sites on the west coast of Australia, Abrolhos, Shark Bay, Exmouth and Onslow, intermingled and were probably all drawn from the same stock. Fish from Broome, Kupang (Indonesia), Groote Eylandt-Torres Strait and the cast coast of Australia had distinct faunas of permanent parasites and probably each belonged to a different stock. There was evidence of movement of fish between Broome and the west coast. Abundances of temporary parasites (gill copepods and monogeneans) suggested that males and females on the west coast migrated separately because in several cases the parasite fauna of one sex was more similar to that of fish in an adjacent area than to the opposite sex in the same area. (C) 2001 The Fisheries Society of the British Isles.
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Aim: The pseudo-Pelger-Huet (PH) anomaly has been associated with a variety of primary haematological disorders, infections and drugs. Recently, the development of dysgranulopoiesis characterised by a pseudo-PH anomaly has been reported in two patients with the use of mycophenolate mofetil (MMF) in the setting of heart and/or lung transplantation. We present a further five cases of MMF-related dysgranulopoiesis characterised by a pseudo-PH anomaly occurring after renal transplantation. Methods: All patients were receiving standard immunosuppression protocols for renal transplantation, including a combination of MMF, steroids and either cyclosporin or tacrolimus. Oral ganciclovir was also used for cytomegalovirus prophylaxis in each case. Results: Development of dysplastic granulopoiesis occurred a median of 96 days (range 66-196 days) after transplantation. Moderate or severe neutropaenia (
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Recent studies have shown that phox homology (PX) domains act as phosphoinositide-binding motifs. The majority of PX domains studied show binding to phosphatidylinositol 3-monophosphate (Ptdlns(3)P), an association that allows the host protein to localize to membranes of the endocytic pathway. One issue, however, is whether PX domains may have alternative phosphoinositide binding specificities that could target their host protein to distinct subcellular compartments or allow their allosteric regulation by phosphoinositides other than PtdIns(3)P. It has been reported that the PX domain of sorting nexin 1 (SNX1) specifically binds phosphatidylinositol 3,4,5-trisphosphate (PtdIns(3,4,5)P-3) (Zhong, Q., Lazar, C. S., Tronchere, H., Sato, T., Meerloo, T., Yeo, M., Songyang, Z., Emr, S. D., and Gill, G. N. (2002) Proc. Natl. Acad. Sci. U. S. A. 99,6767-6772). In the present study, we have shown that whereas SNX1 binds PtdIns(3,4,5)P-3 in protein:lipid overlay assays, in liposomes-based assays, binding is observed to PtdIns(3)P and phosphatidylinositol 3,5-bisphosphate (PtdIns(3,5)P-2) but not to PtdIns(3,4,5)P-3. To address the significance of PtdIns(3,4,5)P-3 binding, we examined the subcellular localization of SNX1 under conditions in which plasma membrane PtdIns(3,4,5)P-3 levels were significantly elevated. Under these conditions, we failed to observe association of SNX1 with this membrane. However, consistent with the binding to PtdIns(3)P and PtdIns(3,5)P-2 being of more physiological significance was the observation that the association of SNX1 with an early endosomal compartment was dependent on a 3-phosphoinositide-binding PX domain and the presence of PtdIns(3)P on this compartment. Finally, we somal association of SNX1 is important for its ability to regulate the targeting of internalized epidermal growth factor receptor for lysosomal degradation.
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A 12-day-old nestling Gouldian finch (Erythrura [Chloebia] gouldiae) was presented for investigation of a mortality problem in nestling finches raised by Bengalese finch foster parents. On histological examination, large numbers of spores consistent with a microsporidian organism were present within the small intestinal mucosa. Electron microscopy and molecular studies (sequencing the 5' end of the ssu rRNA gene) further defined the organism as Encephalitozoon hellem. Sequence homology with other eukaryotes was determined using a BLASTN search from the NCBI GenBank database. The finch isolate sequences showed greater than 99% homology with those of previously reported human and avian isolates.
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Contaminant transport in coastal aquifers is of increasing interest since, with the development of coastal areas, contaminants from surface sources may enter coastal aquifers and pollute the groundwater flow. Coastal groundwater flow is complicated because of the presence of a freshwater-saltwater diffusion zone and the tidal variation of sea level at the seaward end. This paper investigates experimentally the behaviour of contaminant plumes with different densities in an unconfined coastal aquifer. Experiments were performed in a flow tank filled with glass beads as the porous medium. Results show that the dense contaminant has a more diffusive front than the less dense one in the seaward direction towards the coastline. The plume becomes more diffusive when it travels closer to the saltwater interface. On the contrary, the less dense contaminant presents a relatively sharp outline. It tends to migrate in the upper portion of the aquifer and exits in a concentrated manner over a small discharge area at the coastline, not further seaward under the sea. Non-dimensional parameters show that instabilities occur in our experiments for a density difference of 1.2% or larger between the contaminant and the ambient water. The experimental results provide guidance for field monitoring and numerical modelling. (C) 2002 Elsevier Science Ltd. All rights reserved.
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Dinoflagellates exist in symbiosis with a number of marine invertebrates including giant clams, which are the largest of these symbiotic organisms. The dinoflagellates (Symbiodinium sp.) live intercellularly within tubules in the mantle of the host clam. The transport of inorganic carbon (Ci) from seawater to Symbiodinium (=zooxanthellae) is an essential function of hosts that derive the majority of their respiratory energy from the photosynthate exported by the zooxanthellae. Immunolocalisation studies show that the host has adapted its physiology to acquire, rather than remove CO2, from the haemolymph and clam tissues. Two carbonic anhydrase (CA) isoforms (32 and 70 kDa) play an essential part in this process. These have been localised to the mantle and gill tissues where they catalyse the interconversion of HCO3- to CO2, which then diffuses into the host tissues. The zooxanthellae exhibit a number of strategies to maximise Ci acquisition and utilisation. This is necessary as they express a form II Rubisco that has poor discrimination between CO2 and O-2. Evidence is presented for a carbon concentrating mechanism (CCM) to overcome. this disadvantage. The CCM incorporates the presence of a light-activated CA activity, a capacity to take up both HCO3- and CO2, an ability to accumulate an elevated concentration of Ci within the algal cell, and localisation of Rubisco to the pyrenoid. These algae also express both external and intracellular CAs, with the intracellular isoforms being localised to the thylakoid lumen and pyrenoid. These results have been incorporated into a model that explains the transport of Ci from seawater through the clam to the zooxanthellae.
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Experimental infections were used to track the fate of the dorsal sensilla of Merizocotyle icopae (Monogenea: Monocotylidae) from nasal tissue of the shovelnose ray, Rhinobatos typus (Rhinobatidae). Scanning and transmission electron microscopy revealed that 3 types of uniciliate dorsal sensilla exist at different times in the development of the monogenean. Type 1 sensilla have little or no invagination where the cilium exits the distal end of the dendrite and possess a ring of epidermis surrounding the cilium distal to the invagination. Type 2 sensilla have a deep invagination where the cilium exits the dendrite. Type 3 sensilla can be distinguished from the other types by the shape of the dendrite. The larvae have predominantly Type I dorsal sensilla, most of which are lost approximately 24 h after infection and a few Type 2 sensilla, which are retained. Additional Type 2 sensilla (termed Adult Type 2 sensilla), which are slightly different morphologically from the Type 2 sensilla of the larvae, form in later stages of development. Numerous Type 3 sensilla are unique to the dorsal surface of adults. Loss of all Type I sensilla upon attachment to the host, R. typus, suggests that these may be chemo- or mechanoreceptors responsible for host location by the swimming infective larvae. Type 2 sensilla appear to be important in the larvae, juveniles, and adults whereas the modality mediated by Type 3 is specific to adults. (C) 2003 Wiley-Liss, Inc.
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O Planeamento Concomitante teve a sua origem no Reino Unido. É um método radical de intervenção social, baseado na Teoria de Afecto (Attachment Theory). O Planeamento Concomitante procura garantir que as crianças vulneráveis nas casas de acolhimento do Estado sejam adoptadas mais rapidamente possível. As crianças são acolhidas no âmbito deste Planeamento durante o período em que está em curso a avaliação da capacidade acolhedora dos pais adoptivos. As crianças sem condições de retorno para as suas famílias são desta forma legalmente adoptadas pelos pais adoptivos com quem as crianças já conseguiram desenvolver laços afectivos.
Host-symbiont interactions in the deep-sea vent mussel Bathymodiolus azoricus : a molecular approach
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Tese de Doutoramento, Ciências do Mar, especialidade de Biologia Marinha, 19 de Dezembro de 2015, Universidade dos Açores.
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Dissertation submitted to the Faculty of Sciences and Technology of New University of Lisbon for obtaining the degree of Master in Environmental Management Systems
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Miracetyma etimaruyagen. et sp. n. is proposed from the gills filaments of Curimata cyprinoides(Linnaeus, 1758), Potamorhina latior(Spix, 1829) and Psectrogaster essequibensis(Gunther, 1864). The species of the new genus is characterized by having a more complex latching antenna. The claw is greatly reduced and has a groove; the third segment has one or two grooves; the first, second and third segments have one or two cuticular extensions. The legs have pectinate setae and the first endopod is greatly modified, very long, and without setae. The first segment of the first endopod is large, strong and elongate and the second segment is subcylindrical, slender and elongate. These modifications imply in a loss of swimming capacity which is linked to secure fixation on the gill filament. As a result, the leg morphology has evolved other functions.
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This study characterized morphologically Trichodina heterodentata Duncan, 1977 from cultivated fingerlings of "pirarucu" Arapaima gigas in Peru. Body and gill smears were air-dried at room temperature, impregnated with silver nitrate and/or stained with gomori trichromic. Prevalence was 100%. Trichodina heterodentata was considered a medium-sized trichodinid with mean body diameter of 56.0+ 5.25 (47.3-76.0) μm, denticulate ring 28.21± 2.71 (20-34.7) μm, adhesive disc 45.7±3.8 (37.1-57.3) μm diameter and number of denticles of 20.7± 2.6 (12-24). The present study reports not only the first occurrence of T. heterodentata in Peru but also the first record of this trichodinid infesting A. gigas. Camparative tables of all reports of T. heterodentata are also presented.
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Relatório de estágio de mestrado em Ensino de Educação Física nos Ensinos Básico e Secundário