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91.
Nunes M. L. Ferreira Da Silva E. De Almeida S. F. P. 《Water, air, and soil pollution》2003,149(1-4):227-250
In order to study the anthropogenic impact of trace metals in the Caima and Mau River basins (north-central Portugal), 415 stream sediment samples were randomly collected in the main streams of these rivers and the minus 80-mesh fraction was analysed by Inductively Coupled Plasma – Optical Emission Spectrometry (ICP-OES). The presence of abandoned mines was identified as the main source of Cu, Pb, Cd and Ni in the area. A strong pair-wise correlation between Pb, Zn, Cd and Ni was found. In this study, the geochemical indices (Contamination Index (CI) and Multiple Pollution Index (MPI)), and the diatom indices (Specific Pollution Index (SPI) and Biological Diatom Index (BDI)) are used to define the Caima and Mau River basins environmental quality. The estimation of the CI and MPI indices shows that the sediments near Coval da Mó area are enriched with Pb, Cd, Zn Ni and Co suggesting an anthropogenic origin of metal contamination in this zone. In order to evaluate the biological effects caused by the trace metals, 17 sites were selected from the two River basins. Surface water and epilithic diatom communities were sampled during the summer of 2001. In general, the water and diatom data showed medium to good water quality. However, samples collected near the mining areas (Coval da Mó) revealed low abundance and diversity of diatom taxa indicating a stressed environment. Some diatoms showed morphologically abnormal valves that may be related to the high level of metal pollution in this area. 相似文献
92.
Luzia Renata Oliveira Dias Ligiane Oliveira Leme José Felipe Warmling Sprícigo Ivo Pivato Margot Alves Nunes Dode 《Reproduction in domestic animals》2020,55(1):11-20
In vitro produced embryos are still sensitive to the freezing process which can be explained, in part, by the high-lipid accumulation that characterizes these embryos. Therefore, we aimed to evaluate the effect of delipidating agents, L-carnitine and the trans-10 cis-12 conjugated linoleic acid (CLA) isomer, on blastocyst development, lipid content, gene expression and cryotolerance when added to embryo culture media. Embryos were cultured in four different media: T1: control (n = 616), synthetic oviduct fluid (SOF) media with 5% foetal bovine serum (FBS); T2: L-carnitine (n = 648), SOF medium with 5% FBS and 0.6 mg/ml of L-carnitine; T3: CLA (n = 627), SOF medium with 5% FBS and 100 μM trans-10 cis-12 CLA; and T4: L-carnitine + CLA: (n = 597), SOF medium with 5% FBS plus 0.6 mg/ml L-carnitine and 100 μM trans-10 cis-12 CLA. Supplementation of culture medium with either or both delipidating agents reduced (p < .05) blastocyst rate on D7 (T1 = 49 ± 3.5; T2 = 39 ± 3.0; T3 = 42 ± 3.9 and T4 = 39 ± 3.9), but did not affected gene expression (p > .05). Although embryos cultured in the presence of L-carnitine contained fewer (p < .05) lipid droplets than the control embryos, they showed a lower re-expansion rate 24 hr post-thaw than those (p < .05). In conclusion, although L-carnitine reduced the amount of lipids in cultured embryos, the use of L-carnitine and CLA during in vitro culture was not able to improve the embryo production and the response to cryopreservation. 相似文献
93.
Sara R. RodriguesCarina Caldeira Bruno B. CastroFernando Gonçalves Bruno Nunes Sara C. Antunes 《Pesticide biochemistry and physiology》2011,99(2):181-188
Inhibition of cholinesterases (ChEs) has been widely used as an environmental biomarker of exposure to organophosphates (OP) and carbamate (CB) pesticides. More recently, this biomarker has been suggested as a putative biomarker for exposure to detergents. The use of cholinesterase inhibition as effect criterion in Ecotoxicology requires the previous characterization of the specific enzymatic forms that may be present in different tissues or organs. Different ChEs isoforms may be present in the same tissue and may exhibit distinct sensitivities towards environmental contaminants. This work intended to characterize the soluble ChEs present in pumpkinseed sunfish (Lepomis gibbosus) total head and dorsal muscle homogenates, through the use of different substrates and selective inhibitors of cholinesterasic activity. Also, the in vitro effects of sodium dodecylsulphate (SDS - anionic detergent) and chlorfenvinphos (organophosphate pesticide) on the enzymatic activity of the mentioned species were investigated. In general terms, the predominant cholinesterasic form present in both tissues was acetylcholinesterase. Chlorfenvinphos was responsible for inhibitory effects on AChE activity, while SDS did not cause any significant effect. These results suggest that in environmental monitoring programs, L. gibbosus head and dorsal muscle AChE can be an adequate diagnostic tool for exposure to OP pesticides; this conclusion however is not applicable to detergent residues. We also discuss the usefulness of L. gibbosus as an alternative model system and valuable option for freshwater ecotoxicological monitoring programs. 相似文献
94.
The influence of different nitrogen (N) forms on salt tolerance of Pisum sativum L. was investigated. Plants of the pea cultivar “Resal” were subjected to 0 (control) or 90 mM NaCl and one of the following nitrogen forms: 5 mM mineral N supplied as either NO , NH , or NH4NO3 or N supplied by biological N2 fixation (inoculated with Rhizobium leguminosarum bv. viciae). Root and shoot biomass were determined 15, 30, 45, and 60 d after emergence, and Na+, K+, and Cl– concentrations were determined by capillary electrophoresis. Nitrogen sources induced significant differences in plant growth and in ion accumulation and distribution and in differentially affected salt tolerance. In the absence of salt, the largest biomass accumulation was obtained with NH4NO3. In the presence of NaCl, NO ‐fed plants experienced less salt toxicity than plants supplied with other N sources, as indicated by lower Na+ and Cl– and higher K+ concentrations in the shoot. The results also suggest that it is possible to establish an effective symbiosis under saline conditions, provided that a salt‐tolerant Rhizobium isolate with good N2‐fixing ability is used. The use of the appropriate N‐fertilizer source can enhance the growth of Pisum sativum. Hence, NH4NO3 may be preferably used under non‐saline and NO under moderately saline conditions. 相似文献
95.
Silva SV Soares AT Batista AM Almeida FC Nunes JF Peixoto CA Guerra MM 《Reproduction in domestic animals》2011,46(5):874-881
The aim of the present study was to evaluate the in vitro and in vivo effect of the addition of superoxide dismutase (SOD) and reduced glutathione (GSH) to ram semen freezing extender. Significant differences (p < 0.05) were detected between groups regarding total motility (TM), straightness (STR) and wobble (WOB), for which the GSH 7 mM group had lesser TM and better STR than the other groups and the GSH 5 and 7 mM groups had higher wobble values than the control, SOD 25 and 100 U/ml groups. The ultrastructural analysis revealed that the acrosome was better preserved after freezing in the SOD 100 U/ml and GSH 2 and 5 mM (p < 0.05) groups than the other groups, whereas mitochondria in both the control group and the 7 mM GSH group suffered the greatest damage. The plasma membrane remained preserved after freezing, regardless of the group. For in vivo fertilization, the SOD group achieved better results than the GSH group (p > 0.05). It can therefore be concluded that the addition of SOD 100 U/ml and GSH 2 and 5 mM preserves the acrosome integrity of frozen ram spermatozoa, while the addition of SOD 100 U/ml to Tris egg-yolk extender offers protection to the membranes of sperm cells after thawing. 相似文献
96.
M M Smith L M Massoudi J D Nunes W C McCain 《American journal of veterinary research》1992,53(2):242-245
Tooth surface and interradicular area (furcation) measurements were taken of 20 first mandibular molar teeth obtained randomly from canine cadavers. The lingual furcation entrance had a mean width of 1.2 +/- 0.3 mm. The buccal furcation entrance had a mean width of 1.3 +/- 0.4 mm. There was no significant difference between mean furcation entrance measurements. The horizontal attachment area between the cementoenamel junction and the coronal roof of the lingual furcation was 1.1 +/- 0.4 mm. The horizontal attachment area between the cementoenamel junction and the coronal roof of the buccal furcation (0.5 +/- 0.3 mm) was significantly different from the lingual horizontal attachment area. Distal root length and mesial root length were 16.0 +/- 1.5 mm and 16.1 +/- 1.6 mm, respectively. The mean coefficient of variation for variables measured was 14.0%. Tooth size did not have a significant effect on furcation entrance measurement. All teeth had a concavity coronal to the furcation area, which extended apically for a mean distance of 65.6% of the distal root length and 83.8% of the mesial root length. Furcation anatomy of the first mandibular molar is complex and may be a contributing factor in periodontal disease involving the interradicular area. 相似文献
97.
Souza MR Moreira JL Barbosa FH Cerqueira MM Nunes AC Nicoli JR 《Veterinary microbiology》2007,120(1-2):142-150
In the present study, lactic acid bacteria (LAB) from the cecum of chickens bred either under intensive (commercial broilers) or extensive (free-range) conditions were isolated, identified and some of their probiotic characteristics determined. The LAB identified by 16S-23S rRNA PCR-ARDRA were mainly of Lactobacillus species and to a lesser extent of Enterococcus spp. for all animals. Free-range chickens showed a higher presence of Lactobacillus acidophilus while Lactobacillus reuteri and Lactobacillus johnsonii were more frequently recovered from commercial broilers. Lactobacillus crispatus was found only in commercial broilers, Lactobacillus vaginalis and Lactobacillus agilis only in free-range chickens and Lactobacillus salivarius in both types. Enterococcus isolates from ceca of commercial broilers showed a higher resistance to antimicrobial drugs. Lactobacillus isolates from free-range chickens presented a higher frequency of in vitro antagonistic activity against selected pathogens than from commercial broilers. All LAB isolates had predominantly non-hydrophobic surfaces, but with variations depending on age of the chickens and breeding conditions. Animal breeding caused variation on composition, antimicrobial susceptibility, antagonistic activity and surface hydrophobicity of LAB from chicken cecum. LAB isolates from ceca of free-range chickens have potential as probiotic agents, which may be used in the future as replacing the use of antimicrobials as growth promoters. 相似文献
98.
Francisco Henrique Nunes da Silva Alves Isadora Cristófoli Pereira Samuel Alves dos Santos Ana Leticia Rocha Monteiro Pedro Marcus Pereira Vidigal Acelino Couto Alfenas Jorge Luis Badel 《Plant pathology》2023,72(1):130-143
Erwinia psidii (Eps) is the causal agent of emerging diseases of eucalypt and guava; however, the mechanisms underlying its pathogenicity are not fully understood. Here, we predicted factors involved in the ability of Eps to cause disease on its host plants. For that, the genomes of four Eps strains exhibiting different virulence on eucalypt were sequenced, and hrp/hrc genes coding for the type III secretion system (T3SS), effectors injected into the plant cell cytoplasm through the T3SS (T3SEs) and their plant subcellular localizations, as well as proteins deployed to the host apoplast, were predicted. It was found that Eps possesses a complete hrp/hrc gene cluster based on comparison with Erwinia amylovora. A total of 18 T3SEs were predicted, 11 of which were shared among all strains, none were exclusive to any strain and seven were absent in at least one strain. No sequence variation among strains was found for five T3SE candidates whereas extensive variation was found for six, suggesting the latter may be determinants of virulence differences. The T3SE candidates are predicted to target the plant cell nucleus, cytoplasm, mitochondrion, chloroplast and peroxisome. The predicted apoplastic effector repertoire common to all four strains was over-represented in proteins of unknown functions or predicted to possess enzymatic activities, among which the most abundant were oxidoreductases and peptidases. Proteins with lytic transglycosylase activity were predicted in strain-specific apoplastic effector repertoires. These results provide an important framework for future research aimed at uncovering the factors underlying Eps pathogenicity. 相似文献
99.
Possamai Ana Paula Silva Alcalde Claudete Regina de Souza Rodrigo Gomes Ludmila Couto de Macedo Francisco de Assis Fonseca Martins Elias Nunes 《Tropical animal health and production》2015,47(1):259-263
Tropical Animal Health and Production - The objective of this study was to evaluate the effect of feeding Saanen goat kids with calcium salts of fatty acids (CSFA) in diet, on intake, performance,... 相似文献
100.
Phillips RJ Davis BJ Tanaka KL Byrne S Mellon MT Putzig NE Haberle RM Kahre MA Campbell BA Carter LM Smith IB Holt JW Smrekar SE Nunes DC Plaut JJ Egan AF Titus TN Seu R 《Science (New York, N.Y.)》2011,332(6031):838-841
Shallow Radar soundings from the Mars Reconnaissance Orbiter reveal a buried deposit of carbon dioxide (CO(2)) ice within the south polar layered deposits of Mars with a volume of 9500 to 12,500 cubic kilometers, about 30 times that previously estimated for the south pole residual cap. The deposit occurs within a stratigraphic unit that is uniquely marked by collapse features and other evidence of interior CO(2) volatile release. If released into the atmosphere at times of high obliquity, the CO(2) reservoir would increase the atmospheric mass by up to 80%, leading to more frequent and intense dust storms and to more regions where liquid water could persist without boiling. 相似文献