992 resultados para Yangtze River Delta
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Resumo:Sarcoides são tumores fibroblásticos, considerados os tumores de pele mais comuns em pele de equinos e que raramente apresentam regressão espontânea. Papilomavírus bovino (BPV) tipos 1 e 2 são relacionados com a patogenia do sarcoide e, provavelmente, o BPV tipo 13 (BPV13), recentemente descrito, também pode estar associado com a formação dessa lesão. Neste estudo, 20 amostras de lesões cutâneas, sendo 12 constituídas por tecidos frescos e 8 amostras de tecido fixado em formalina e embebido em parafina, provenientes de 15 cavalos foram utilizadas para a identificação do DNA de BPV. A análise histopatológica (HE) confirmou todas as lesões como sarcoide. Para a amplificação do DNA de papilomavírus (PV) foram realizadas três reações de PCR. Como triagem, os primers IFNR2/IDNT2 foram utilizados para amplificar um fragmento da ORF L1 do PV. O segundo par de primersutilizado é complementar a sequência dos genes E5 e L2 de BPVs 1, 2 e 13. O terceiro par de primers(FAP59/FAP64) utilizado tem o gene L1 como alvo. A primeira e a segunda PCRs permitiram amplificar produtos em todas as amostras avaliadas. Entretanto, na terceira reação, na qual foram utilizados os primers FAP, foi possível amplificar produtos com tamanho molecular esperado somente nas amostras constituídas por tecidos frescos. O sequenciamento de nucleotídeos e as análises filogenéticas realizadas nos fragmentos E5L2 resultaram na identificação de BPV1, 2 e 13 em 14 (70%), 2 (10%) e em 4 (20%) amostras de sarcoides, respectivamente. As amostras de sarcoides de um dos animais continha somente o DNA de BPV1. Entretanto, nas amostras provenientes do segundo cavalo foi possível identificar o DNA de três tipos de Deltapapillomavirus bovino (BPV1, 2 e 13) em lesões distintas. Este estudo ratifica a presença do DNA de BPV1, 2 e 13 em lesões de sarcoides em equinos, além de identificar três tipos de BPVs em um mesmo animal e descrever pela primeira vez no Brasil a presença de BPV1 e 2 nesse tipo de lesão.
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Abstract: We sampled ticks from specimens of the rococo toad Rhinella schneideriby flannel dragging on two Islands located in the São Francisco River near the Três Marias hydroelectric dam, southeastern Brazil. A total of 120 toads was examined, of which 63 (52.5%) were parasitized only by Amblyomma rotundatumtotaling 96 larvae, 163 nymphs and 134 females. The burden of parasitism ranged from one to 43 ticks, with a mean intensity of infestation of 6.2±5.5 ticks per host. The tick A. rotundatumexhibited highly aggregated distribution. Peak abundance of larvae and nymphs occurred in the dry season (May to September), whereas peak abundance of females occurred in the wet season (October to April). We collected most ticks near the head and hind limbs of R. schneideri. The finding of two engorged A. rotundatumnymphs in the same resting places of two toads and the absence of this species in the dragged areas suggest a nidicolous behavior at the studied site.
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Abstract: Equine infectious anemia (EIA) is a transmissible and incurable disease caused by a lentivirus, the equine infectious anemia virus (EIAV). There are no reports in the literature of this infection in Equidae on Marajo Island. The objective of this study was to diagnose the disease in the municipalities of Cachoeira do Arari, Salvaterra, Santa Cruz do Arari and Soure, on Marajó Island, state of Pará, Brazil. For serological survey samples were collected from 294 horses, over 5-month-old, males and females of puruca and marajoara breeds and from some half-breeds, which were tested by immunodiffusion in Agar gel (AGID). A prevalence of 46.26% (136/294) positive cases was found. EIA is considered endemic in the municipalities studied, due to the ecology of the region with a high numbered population of bloodsucking insect vectors and the absence of official measures for the control of the disease.
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Larsmo-Öjasjön i Österbotten skapades genom invallningar på 1960-talet pga. industrins behov av sötvatten. Sedan dess har vattenområdet drabbats av återkommande försurning och fiskdöd, och invallningen har ofta beskyllts för problemen. Avhandlingen undersöker syrabelastningen i området; bl.a. hur markanvändning, hydrologi och klimatförändringen påverkar belastningen. Konsekvenserna undersöks med fiskyngel som bioindikator, och olika miljömetoder testas och diskuteras. Ökad kunskap om försurningen hjälper oss att tillämpa effektiva miljömetoder och få förbättrad vattenkvalitet i framtiden. Den primära orsaken till den försämrade vattenkvaliteten under de senaste 40 åren är intensiv dikning av svavelrika sediment. Detta leder till oxidering av svavlet till svavelsyra och uppkomst av sura sulfatjordar. Syran löser upp mängder med toxiska metaller som spolas ut i vattendragen. Undersökningen visar att tiotusentals ton svavelsyra tillsammans med stora mängder metaller rinner till Larsmo-Öjasjön per år från sura sulfatjordar. Åarna bidrar med mest belastning, men den sammanlagda belastningen från de otaliga dikena och bäckarna är oväntat stor. Andra potentiella källor till försurningen, t.ex. muddringar och humussyror, beräknas vara obetydliga. Syra- och metallbelastningen varierar kraftigt med hydrologin, dvs. störst belastning sker under vår- och höstflöden. En eventuell klimatförändring kan ändra på avrinningsmönstret och orsaka mera belastning vintertid. Den årligt återkommande syra- och metallbelastningen kan ofta hindra lakens förökning, vilket kan ha större långtgående konsekvenser för fiskpopulationerna än de relativt sällsynta stora surchockerna med synlig fiskdöd. För att förebygga skador på vattendragen bör man undvika att dränera svavelrika sedimenten. På redan existerande sura sulfatjordar visade sig kontroll av grundvattennivån kunna möjliggöra en effektiverad markanvändning utan märkbart ökade miljökonsekvenser.
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Floristic comparison of periphyton communities from three systems with different hydrodynamic regimes (lentic, semilotic, and lotic) was carried out during high and low water periods on the Upper Paraná River floodplain. For each period and system, glass slides were sampled every two days during 18-day periods, and Eichhornia azurea Kunth petioles were sampled three times. A total of 228 species was collected, representing 12 classes, mainly diatoms and desmids. The highest species-richness was found in communities from lentic system and during high water. Species richness in the lotic system was more stable over succession and hydrological periods. Algal taxonomic structure in river community was clearly separated from the other two systems, with 43% of similarity level. The hydrological period was next in importance, followed last by the substratum type, with communities associated at 65-78% similarity levels, depending on system and hydrological period. The type of system, but not the water levels,was the main factor that influenced community richness, followed by disturbances caused by flood pulses and the operation of reservoirs upstream. The periphyton on artificial and natural substrata presented high degree of similarity.
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Floristic and phytosociological surveys were carried out for 12 months in the Embrapa-SPSB, Petrolina, Pernambuco, Brazil. A transect was laid on starting at the river bank extending for 790 m away from the river and divided into 140 10 × 10 m contiguous plots. In each plot, all standing plants, alive or dead, with stem diameter at soil level > 3 cm and total height > 1 m were sampled. Along this transect, an elevation range of 9.40 m was registered and five topographical environments were identified: riverside (MR), dike (D), floodable depression (DI), boundary terrace (TL) - all of them belonging to the fluvial terrace with Fluvic Neosol and Haplic Cambisol both silty textured eutrophic soils - and the inlander tableland (TS), with medium sandy-textured Red-Yellow Argisols. Fourty-eight species/morphospecies, distributed into 39 genera and 21 families, were identified. Four phytogeoenvironments (MR, D + TL, DI + TL, and TS) were registered based on environmental variations and floristic similarities among plots using cluster analyses. The MR environment showed the largest total density, total basal area, maximum and medium heights and maximum diameter. Moreover, it had 8.1% of plants with heights above 8 m against 0.6% for D + TL, 0.2% for DI + TL, and 0% for TS. The species with the largest importance value were Inga vera subsp. affinis (DC.) T.D. Pennington in MR, Mimosa bimucronata Kunth in D + TL and DI + TL and M. tenuiflora (Willd.) Poir. in TS.
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The present study deals with a survey of the order Alismatales (except Araceae) in the upper and middle Araguaia River region located between the states of Mato Grosso and Goiás, Brazil. Field expeditions were carried out during the rainy and dry seasons. The route covered approximately 2,000 km and 41 aquatic environments were visited. Thirteen taxa, representing the families Alismataceae (nine), Hydrocharitaceae (three) and Najadaceae (one) were identified. Keys for the identification of families and species in field, brief diagnoses, schematic illustrations and relevant comments were elaborated based on field observations as well as on the analysis of the specimens collected.
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There is an important pioneer vegetation formation along the Xingu River in the area where the Belo Monte hydroelectric dam is being constructed that is highly adapted to a seasonally fluctuating water levels. The aim of this study was to examine the habitat and flora of the pioneer formations in the Belo Monte area. The area was divided in three sections for study purposes (Reservoir, Low Flow, and Control) that were expected to experience different degrees of impact from the dam project. The calculations of habitat losses were based on satellite imagery classifications, and a total of 111 plots were established in the three areas for vegetation sampling. Habitat losses of the pioneer formations will total 89.7% when the project is fully functional. Forty-five of the 72 recorded species are restricted to single areas. Species richness and diversity were significantly lower in the control area. The completion of the Belo Monte reservoir will result in habitat reductions and will consequently reduce the richness and diversity of pioneer formations. Studies suggest monitoring the populations located in the reduced flow area to determine possible impacts resulting from changes in the regional hydrological cycle caused by the Xingu River dam.
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The genetic variability of the "curimba", Prochilodus lineatus, from three locations in the Paraná river basin, was investigated by starch gel electrophoresis. A total of 160 specimens were analyzed for 19 enzymes, 12 of which permitted successful interpretation of electrophoretic patterns. Eighteen loci were identified and six of them proved to be polymorphic (EST-1*, EST-2*, IDH-1*, PGM-1*, PGM-2*, LDH-2*). Mean heterozygosity was considered high (13%) by comparison with the literature. A low level of differentiation was found among subpopulations, with mean F ST = 0.018. Values of genetic distance and genetic identity suggest that, at least along this stretch of the river, P. lineatus comprises a single breed with high gene flow. This analysis has important implications for fishery management, aquaculture, and conservation of the stocks
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The purpose of the present study was to investigate the in vitro and in vivo effects of aluminum sulfate on delta-aminolevulinic acid dehydratase (ALA-D) activity from the brain, liver and kidney of adult mice (Swiss albine). In vitro experiments showed that the aluminum sulfate concentration needed to inhibit the enzyme activity was 1.0-5.0 mM (N = 3) in brain, 4.0-5.0 mM (N = 3) in liver and 0.0-5.0 mM (N = 3) in kidney. The in vivo experiments were performed on three groups for one month: 1) control animals (N = 8); 2) animals treated with 1 g% (34 mM) sodium citrate (N = 8) and 3) animals treated with 1 g% (34 mM) sodium citrate plus 3.3 g% (49.5 mM) aluminum sulfate (N = 8). Exposure to aluminum sulfate in drinking water inhibited ALA-D activity in kidney (23.3 ± 3.7%, mean ± SEM, P<0.05 compared to control), but enhanced it in liver (31.2 ± 15.0%, mean ± SEM, P<0.05). The concentrations of aluminum in the brain, liver and kidney of adult mice were determined by graphite furnace atomic absorption spectrometry. The aluminum concentrations increased significantly in the liver (527 ± 3.9%, mean ± SEM, P<0.05) and kidney (283 ± 1.7%, mean ± SEM, P<0.05) but did not change in the brain of aluminum-exposed mice. One of the most important and striking observations was the increase in hepatic aluminum concentration in the mice treated only with 1 g% sodium citrate (34 mM) (217 ± 1.5%, mean ± SEM, P<0.05 compared to control). These results show that aluminum interferes with delta-aminolevulinate dehydratase activity in vitro and in vivo. The accumulation of this element was in the order: liver > kidney > brain. Furthermore, aluminum had only inhibitory properties in vitro, while in vivo it inhibited or stimulated the enzyme depending on the organ studied.
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Lead has been shown to produce cognitive and motor deficits in young rats that could be mediated, at least in part, by inhibition of the zinc-containing heme biosynthetic enzyme delta-aminolevulinate dehydratase (ALA-D). In the present study we investigated the effects of lead and/or zinc treatment during the second stage of rapid postnatal brain development on brain, kidney and blood ALA-D specific activity, as well as the negative geotaxis behavior of rats. Eight-day-old Wistar rats were injected intraperitoneally with saline, lead acetate (8 mg/kg) and/or zinc chloride (2 mg/kg) daily for five consecutive days. Twenty-four hours after treatment, ALA-D activity was determined in the absence and presence of DL-dithiothreitol (DTT). The negative geotaxis behavior was assessed in 9- to 13-day-old rats. Treatment with lead and/or zinc did not affect body, brain or kidney weights or brain- or kidney-to-body weight ratios of the animals. In spite of the absence of effect of any treatment on ALA-D specific activity in brain, kidney and blood, the reactivation index with DTT was higher in the groups treated with lead or lead + zinc than in the control group, in brain, kidney and blood (mean ± SEM; brain: 33.33 ± 4.34, 38.90 ± 8.24, 13.67 ± 3.41; kidney: 33.50 ± 2.97, 37.60 ± 2.67, 15.80 ± 2.66; blood: 63.95 ± 3.73, 56.43 ± 5.93, 31.07 ± 4.61, respectively, N = 9-11). The negative geotaxis response behavior was not affected by lead and/or zinc treatment. The results indicate that lead and/or zinc treatment during the second stage of rapid postnatal brain growth affected ALA-D, but zinc was not sufficient to protect the enzyme from the effects of lead in brain, kidney and blood.
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The present study analyzes Na+ and K+ disturbances caused by low pH in two catfish species from the Amazon River. Corydoras adolfoi inhabits ion-poor, black-stained, low pH (3.5-4.0) waters, while C. schwartzi is native to ion-rich waters at circumneutral pH. Fish were exposed to pH 3.5 Ca2+-free, and Ca2+-enriched (~500 µmol/l) water to determine the protective effects of calcium. Net Na+ and K+ fluxes were measured in the water collected from the fish experimental chambers. C. adolfoi was unable to control the Na+ efflux at low pH, exhibiting Na+ loss up to -594 ± 84 nmol g-1 h-1 during the first hour. After 3 and 6 h, net Na+ flux increased by 7- and 23-fold, respectively. In C. schwartzi, at pH 3.5, the initial high Na+ loss (-1,063 ± 73 nmol g-1 h-1) was gradually attenuated. A K+ loss occurred in both species, but remained relatively constant throughout exposure. High [Ca2+] affected ion losses in both species. C. adolfoi had 70% loss attenuation, indicating incapacity to control Na+ efflux. In C. schwartzi, elevated [Ca2+] completely prevented the Na+ losses caused by exposure to low pH. Rather different patterns were seen for K+ fluxes, with C. adolfoi showing no K+ disruption when exposed to low pH/high [Ca2+]. Thus, C. adolfoi loses Na+ during acid exposure, but has the ability to control K+ loss, while C. schwartzi controls diffusive Na+ loss but exhibits a slightly higher K+ loss. Ion balance was influenced by [Ca2+] at low pH in C. schwartzi but not in C. adolfoi.
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The interaction of the product of H2O2 and (PhSe)2 with delta-aminolevulinate dehydratase (delta-ALA-D) from mammals and plants was investigated. (PhSe)2 inhibited rat hepatic delta-ALA-D with an IC50 of 10 µM but not the enzyme from cucumber leaves. The reaction of (PhSe)2 with H2O2 for 1 h increased the inhibitory potency of the original compound and the IC50 for animal delta-ALA-D inhibition was decreased from 10 to 2 µM. delta-ALA-D from cucumber leaves was also inhibited by the products of reaction of (PhSe)2 with H2O2 with an IC50 of 4 µM. The major product of reaction of (PhSe)2 with H2O2 was identified as seleninic acid and produced an intermediate with a lambdamax at 265 nm after reaction with t-BuSH. These results suggest that the interaction of (PhSe)2 with mammal delta-ALA-D requires the presence of cysteinyl residues in close proximity. Two cysteine residues in spatial proximity have been recently described for the mammalian enzyme. Analysis of the primary structure of plant delta-ALA-D did not reveal an analogous site. In contrast to (PhSe)2, seleninic acid, as a result of the higher electrophilic nature of its selenium atom, may react with additional cysteinyl residue(s) in mammalian delta-ALA-D and also with cysteinyl residues from cucumber leaves located at a site distinct from that found at the B and A sites in mammals. Although the interaction of organochalcogens with H2O2 may have some antioxidant properties, the formation of seleninic acid as a product of this reaction may increase the toxicity of organic chalcogens such as (PhSe)2.