924 resultados para Marked Animals
Resumo:
A esquistossomose acomete 207 milhões de pessoas, com mais de 200 mil mortes anuais. Seu principal agente etiológico é o helminto Schistosoma e o principal modelo experimental, o camundongo. Linhagens de camundongos selecionadas geneticamente para susceptibilidade (TS) e resistência (TR) a tolerância imunológica constituem bons modelos para o estudo da resposta imunológica específica e inespecífica nas infecções. O objetivo deste trabalho foi caracterizar a infecção experimental por S. mansoni nestes camundongos, evidenciando a imunopatologia por diversos parâmetros na fase aguda da infecção. TR e TS não diferiram quanto a penetração de cercárias, recuperação de vermes adultos, fecundidade/produtividade de ovos das fêmeas de S. mansoni, mas predominaram ovos mortos em TS. Quanto maior o número de casais, maior a probabilidade de troca de casais e regressão sexual da fêmea, além de pequena redução da produtividade de ovos. Análise ultraestrutural dos parasitos machos recuperados de TS apresentaram tubérculos edemaciados, espinhos encurtados e em menor densidade que os parasitos dos TR. O tegumento dos parasitos recuperados de TS apresentou-se desorganizado, intensamente vacuolizado e com tendência a se desprender da superfície e espinhos internalizados e células vitelínicas desorganizadas. TS desenvolveram granulomas hepáticos grandes, com fibras radiais e predomínio do estágio exsudativo-produtivo com características de fase produtiva (EP/P), enquanto camundongos TR desenvolveram granulomas menores, com fibras concêntricas e predomínio de granulomas exsudativo-produtivos. TS desenvolveu hepatomegalia mais acentuada na fase aguda da infecção e exacerbada esplenomegalia na fase crônica. A aspartato aminotransferase mais elevada nos TR foi coerente com a acentuada histólise nos granulomas iniciais dos TR. É possível que a histólise menor em TS tenha contribuído para sua intensa hepatomegalia na fase aguda. Leucócitos totais séricos aumentaram em TS, nas fases aguda e crônica, mas não em TR. TS apresentaram anemia durante a fase crônica da infecção, possivelmente devido ao desvio na hematopoiese medular para a produção de leucócitos ou apoptose das hemácias. A mieloperoxidase neutrofílica hepática e no íleo foi maior em TS e a peroxidase de eosinófilos foi mais elevada no íleo do TS. Ambas as linhagens produziram IFN-γ, mas os níveis funcionais de IFN-γ foram diferentes nas duas linhagens em cultura de células. É possível que a imunopatologia hepática grave na linhagem TS possa estar relacionada aos altos títulos IFN-γ. TS produziu IL-10 em maior quantidade, entretanto esta citocina não foi capaz de regular o crescimento exacerbado dos granulomas hepáticos. Altos títulos de IL-4 na linhagem TS também são coerentes com a exacerbação dos granulomas, pois, como a IL-13, a IL-4 induz síntese de colágeno e está relacionada ao desenvolvimento da fibrose no granuloma esquistossomótico. Observamos redução do percentual relativo de células T CD4+ hepáticas de animais infectados em ambas as linhagens e redução percentual nas subpopulações de linfócitos B na medula óssea (precursores, linfócitos B imaturos, maduros e plasmócitos) mais acentuada em TS que em TR, possivelmente devido a extensa mobilização de B imaturos induzida pela inflamação ou desvio da hematopoiese para síntese de granulócitos em TS. Quantitativamente, TR não alterou suas subpopulações de linfócitos B. TS e TR são bons modelos para estudo da resposta imunológica na infecção esquistossomótica experimental. Novos estudos são necessários para confirmar nossas propostas e compreender os mecanismos envolvidos na diferença da resposta imunológica dessas linhagens na relação schistosoma-hospedeiro.
Resumo:
The purpose of this study was to validate aging results of juvenile Shortfin Mako (Isurus oxyrinchus) by vertebral band counts. Vertebrae of 29 juvenile Shortfin Mako marked with oxytetracycline (OTC) were obtained from tag-recapture activities to determine centrum growth-band deposition. Tagging occurred off southern California from 1996 to 2010, and time at liberty of the 29 sharks ranged from 4 months to 4.4 years (mean=1.3 years). Growth information also was obtained from length-frequency modal analyses (MULTIFAN and MIXDIST) by using a 29-year data set of commercial and research catch data, in addition to a tag-recapture growth model (e.g, the GROTAG model). For vertebrae samples used for age validation, shark size at time of release ranged from 79 to 142 cm fork length (FL) and from 98 to 200 cm FL at recapture. Results from band counts of vertebrae distal to OTC marks indicate 2 band pairs (2 translucent and 2 opaque) are formed each year for Shortfin Mako of the size range examined. Length-frequency analyses identified 3 age class modes. Growth rate estimates from 26.5 to 35.5 cm/year were calculated for the first age-class mode (85 cm FL) and from 22.4 to 28.6 cm/year for the second age-class mode (130 cm FL). Results from the tag-recapture growth model revealed fast growth during time at liberty for tagged fish of the 2 youngest age classes. Collectively, these methods suggest rapid growth of juvenile Shortfin Mako in the southern California study area and indicate biannual deposition of growth bands in vertebrae for the first 5 years.
Resumo:
NOAA’s National Centers for Coastal Ocean Science (NCCOS) conducts and supports research, monitoring, assessments, and technical assistance to meet NOAA’s coastal stewardship and management responsibilities. In 2001 the Biogeography Branch of NCCOS partnered with NOAA’s National Marine Sanctuary Program (NMSP) to conduct biogeographic assessments to support the management plan updates for the sanctuaries. The first biogeographic assessment conducted in this partnership focused on three sanctuaries off north/ central California: Cordell Bank, Gulf of the Farallones and Monterey Bay. Phase I of this assessment was conducted from 2001 to 2004, with the primary goal to identify and gather the best available data and information to characterize and identify important biological areas and time periods within the study area. The study area encompasses the three sanctuaries and extends along the coastal ocean off California from Pt. Arena to Pt. Sal (35°-39°N). This partnership project was lead by the NCCOS Biogeography Branch, but included over 90 contributors and 25 collaborating institutions. Phase I results include: 1) a report on the overall assessment that includes hundreds of maps, tables and analyses; 2) an ecological linkage report on the marine and estuarine ecosystems along the coast of north/central California, and 3) related geographic information system (GIS) data and other summary data files, which are available for viewing and download in several formats at the following website: http://ccma.nos.noaa.gov/products/biogeography/canms_cd/welcome.html Phase II (this report) was initiated in the Fall of 2004 to complete the analyses of marine mammals and update the marine bird colony information. Phase II resulted in significant updates to the bird and mammal chapters, as well as adding an environmental settings chapter, which contains new and existing data and maps on the study area. Specifically, the following Phase II topics and items were either revised or developed new for Phase II: •environmental, ecological settings – new maps on marine physiographic features, sea surface temperature and fronts, chlorophyll and productivity •all bird colony or roost maps, including a summary of marine bird colonies •updated at-sea data CDAS data set (1980-2003) •all mammal maps and descriptions •new overall density maps for eight mammal species •new summary pinniped rookery/haulout map •new maps on at-sea richness for cetaceans and pinnipeds •most text in the mammal chapter •new summary tables for mammals on population status and spatial and temporal patterns
Resumo:
We have recently exchanged and integrated into a single database tag detections for conch, teleost and elasmobranch fish from four separately maintained arrays in the U.S. Virgin Islands including the NMFS queen conch array (St. John nearshore), NOAA’s Biogeography Branch array (St. John nearshore & midshelf reef); UVI shelf edge arrays (Marine Conservation District, Grammanik & other shelf edge); NOAA NMFS Apex Predator array COASTSPAN (St. John nearshore). The integrated database has over 7.5 million hits. Data is shared only with consent of partners and full acknowledgements. Thus, the summary of integrated data here uses data from NOAA and UVI arrays under a cooperative agreement. The benefits of combining and sharing data have included increasing the total area of detection resulting in an understanding of broader scale connectivity than would have been possible with a single array. Partnering has also been cost-effectiveness through sharing of field work, staff time and equipment and exchanges of knowledge and experience across the network. Use of multiple arrays has also helped in optimizing the design of arrays when additional receivers are deployed. The combined arrays have made the USVI network one of the most extensive acoustic arrays in the world with a total of 150+ receivers available, although not necessarily all deployed at all times. Currently, two UVI graduate student projects are using acoustic array data.
Resumo:
Otolith thermal marking is an efficient method for mass marking hatchery-reared salmon and can be used to estimate the proportion of hatchery fish captured in a mixed-stock fishery. Accuracy of the thermal pattern classification depends on the prominence of the pattern, the methods used to prepare and view the patterns, and the training and experience of the personnel who determine the presence or absence of a particular pattern. Estimating accuracy rates is problematic when no secondary marking is available and no error-free standards exist. Agreement measures, such as kappa (κ), provide a relative measure of the reliability of the determinations when independent readings by two readers are available, but the magnitude of κ can be influenced by the proportion of marked fish. If a third reader is used or if two or more groups of paired readings are examined, latent class models can provide estimates of the error rates of each reader. Applications of κ and latent class models are illustrated by a program providing contribution estimates of hatchery-reared chum and sockeye salmon in Southeast Alaska.
Resumo:
Hermaphroditism, a phenomenon in which one and the same individual produces sperms, the male gamate the ovum, the female gamate, is generally common in plants and lower animals and hence is considered as a primitive character. However, it is rare in higher invertebrates such as insects, spiders, prawns and also in the lower vertebrates to which fishes belong. Prawns and fishes have highly evolved reproductive systems and occur as separate individuals of males and females. Both these groups do have some species which are regurarly hermaphrodites and others which are teratologically hermaphrodites.
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This report deals with the application of knowledge of mangrove ecosystems from around the world to the understanding of the present status of mangroves ecosystems in Pakistan.
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The present communication deals with the feeding trials of brown (Sargassum bovianum), green (Caulerpa faridii) and red (Gracilaria corticola) seaweeds in albino rats for a period of thirty days in order to investigate their digestibility and acceptability as supplementary food for animals. The parameters used were: changes in blood hemoglobin, ESR, MCHC, PCV and plasma vitamin levels. The result revealed that all the three species of seaweeds had acceptability up to 5% level, as no ill effect was noted during the experiment. But at 10% and 20% levels, marked changes were observed in blood parameters with diarrhea, vomiting and convulsions indicating possibilities of either tissue and muscular dystrophy, gastrointestinal tract necrosis or functional disorder of central nervous system. A heavy mortality was noted due to excessive water loss through diarrhea and vomiting. However, no mortality was observed after 22nd day at both 10% and 20% levels with subsided clinical signs. The results suggest that these three seaweed species could be used safely as a supplementary food, in native form, in animals at low concentrations.
Resumo:
Thirteen restriction endonucleases were used to investigate nucleotide sequence variation in the 18S rRNA DNA of 88 individuals from ten Sarcocystis taxa collected as cysts from their intermediate hosts, swine, cattle and water buffalo. A DNA sequence of
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Background: It is widely accepted that the ancestors of Native Americans arrived in the New World via Beringia approximately 10 to 30 thousand years ago (kya). However, the arrival time(s), number of expansion events, and migration routes into the Western
Resumo:
Large intestinal obstruction (LIO) in farm animals can cause a ischaemic necrosis of intestinal tissue, eventually leading to death. The roles of endothelin-1 (ET-1) and nitric oxide (NO) are not well understood in the process of LIO, but evidence suggests that endothelial-derived mediators may participate. In the present study, ET-1 concentration and total nitric oxide synthase (NOS) activity were measured in heart, liver, pancreas, lung and kidney in a model of LIO in sheep. Our data demonstrated that ET-1 concentration and NOS activity were altered, with significant increases of ET-1 in heart, lung and kidney and of NOS activity in pancreas and kidney, but a marked decline of NOS activity in liver (p<0.05). It is postulated that these alterations in NOS activity and ET-1 concentration may contribute to the progressive loss of organ function, and finally lead to death in LIO in sheep.
Resumo:
The present overview summarizes data from one year's study during the period of 1379 to 1380 in the regions by "Anzali" lagoon called "Abkenar" and "Hendkhale". Specimens from this lagoon obtained weekly during mordad and shahrivar mounths (July 21 to september 21). The study included 67 types of 5 phytoplanktonal phylum. In "Abkenar" region Cyanobacters with maximum of 97% and minimum of 64.5% of total combination of phytoplanktones made the dominating combination during the period of study , while in "hendkhale" chyrsophyta with maximum of 89% and minimum of 38.7% of total phytoplanktonal was the dominating figure at the same period of time. Researches on ecological parameteres showed that the avarage dissolved oxygen in -Abkenar" and "hendlchale" regions was 10.7 and 8.0 mg/lit respectivly, also total rate of Phosphat in these regions was 0.085 and 0.15 mg/lit respectivly. This study showed that the rates of Nitrat and Amonium in "Abkenar" region was 0.043 and 0.79 mg / lit while for the same substances in "Ilendkhale" measured 0.08 and 0.7 mg I lit respective. Also the avarage rate of chlorophyll a in these two areas measured 58,38 and 40.45 j.un /ht respectivly. Depending on results of correlation cofficient in "Abkenar" region we had Cyanobacters , water and air temperature , Chlorophyll a and total amount of Phosphat as a poitive correlation with transparency while Amonium and Nitrat showed , a negative correlation , EC and finally dissolved oxygen showed a very low rate of correlation coffiocient. To perform this research 5 genus of Cyanobacteres horn "Anzali" lagoon have been isolated and cultured in a laboratorial conditions Later by using Mouse Bioassay method one of these genus identified as a toxic algae. Levels of LD50 with intra peritoneal injection of toxin on mouse in 24 hours was 660 mg/kg and Levels of LC50 by using Bioassay method on Artemia and Daphnia has been shown 618 and 1000 mg kg respectively. Also the physiological effects of were investigated. algae on two types of Cypronides family called Cyprinus carpi° and Hypophrthabnichthys Resultes of blood analyses of Cypronides who were feeded by toxic algae showed a significant decline (P < 0.05) in white and red blood cells and their hematocrites. Levels of LDH , SGOT and SGPT in their blood serum had a significant increase in porportion to control group (P < 0.05) but there was no evidance a differences in Total Protein levels. Pathological studies show damage and destruction of hepato pancreas and kidney of these fishes. Signs and symptoms of intoxication caused by Cyanobacter called Planktohrix agardlltii in mouse and fish show heptotoxic character. This toxin belongs to cyclicpeptides of microcystines group.