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1.
When using saline waters, sprinkling irrigation at night is a recommended practice to reduce evaporation, salt absorption
by the wetted leaves and its negative effects on crops. We measured shoot ion concentrations (Cl−, Na+ and K+) and total dry matter (TDM) in alfalfa subject to diurnal and nocturnal saline sprinkler irrigations and established potential
relationships among them. The work was carried out along the 2004–2006 growing seasons using EC waters from 0.5 to 5.6 dS m−1. Saline sprinkling irrigations linearly increased shoot Cl− and Na+ and decreased shoot K+. Even though daytime evaporation was much higher than nigh-time, shoot ion accumulation and TDM were similar in the diurnal
and nocturnal irrigations. The salinity tolerance of alfalfa decreased in year 2006 due to increases in shoot Cl− and, particularly, shoot Na+. The lower threshold for shoot Na+ (276 meq kg−1) than for shoot Cl− (726 meq kg−1) shows that alfalfa is more sensitive to Na+ than to Cl−, and that Na+ accumulation is the preponderant cause of alfalfa yield decline after 3 years of sprinkling with saline waters. 相似文献
2.
Adolfo Isla Mnica Saldarriaga‐Crdoba Derie E. Fuentes Romina Albornoz Denise Haussmann Jorge Mancilla‐Schulz Alexis Martínez Jaime Figueroa Ruben Avendao‐Herrera Alejandro Yez 《Journal of fish diseases》2019,42(5):721-737
Piscirickettsia salmonisis the causative bacterial pathogen of piscirickettsiosis, a salmonid disease that causes notable mortalities in the worldwide aquaculture industry. Published research describes the phenotypic traits, virulence factors, pathogenicity and antibiotic‐resistance potential for various P. salmonisstrains. However, evolutionary and genetic information is scarce for P. salmonis. The present study used multilocus sequence typing (MLST) to gain insight into the population structure and evolution of P. salmonis. Forty‐two Chilean P. salmonisisolates, as well as the type strain LF‐89T, were recovered from diseased Salmo salar, Oncorhynchus kisutchand Oncorhynchus mykissfrom two Chilean Regions. MLST assessed the loci sequences of dnaK, efp, fumC, glyA, murG, rpoD and trpB. Bioinformatics analyses established the genetic diversity among P. salmonis isolates (H = 0.5810). A total of 23 sequence types (ST) were identified, 53.48% of which were represented by ST1, ST5 and ST2. Population structure analysis through polymorphism patterns showed few polymorphic sites (218 nucleotides from 4,010 bp), while dN/dS ratio analysis indicated purifying selection for dnaK, epf, fumC, murG, and rpoD but neutral selection for the trpB loci. The standardized index of association indicated strong linkage disequilibrium, suggesting clonal population structure. However, recombination events were detected in a group of seven isolates. Findings included genogroups homologous to the LF‐89T and EM‐90 strains, as well as a seven‐isolate hybrid genogroup recovered from both assessed regions (three O. mykiss and four S. salar isolates). The presented MLST scheme has comparative potential, with promising applications in studying distinct P. salmonis isolates (e.g., from different hosts, farms, geographical areas) and in understanding the epidemiology of this pathogen. 相似文献
3.
Investigation of biofilm production and icaA and icaD genes in Staphylococcus aureus isolated from heifers and cows with mastitis 
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下载免费PDF全文 Lívia Castelani Lucas Eduardo Pilon Thamires Martins Claudia Rodrigues Pozzi Juliana Rodrigues Pozzi Arcaro 《Animal Science Journal》2015,86(3):340-344
Biofilm formation and antimicrobial resistance of Staphylococcus aureus are important virulence factors in cases of mastitis in dairy cows. However, few studies have investigated mastitis strains isolated from heifers. Within this context, the objective of the present study was to investigate biofilm formation on Congo red agar, the presence of the icaA and icaD genes by polymerase chain reaction (PCR), and the percentage of in vitro antimicrobial resistance of 110 S. aureus isolates from mammary gland secretions of heifers and cows with mastitis. PCR detected the icaA and icaD genes in 98% and 100% of isolates, respectively. However, only 55.5% of all isolates produced a biofilm on Congo red agar. Antimicrobial susceptibility testing revealed that 47.0% of isolates from heifers and 70.4% of isolates from cows were resistant to at least one of the antimicrobial agents tested. Resistance to penicillin and/or ampicillin was the most frequent (44.5%). These results indicate the need to implement prophylactic and control measures of mastitis for heifers. Heifers and cows can carry resistant strains with the capacity of biofilm production, a fact representing a threat to public health and animal well‐being and generating losses to dairy farmers. 相似文献
4.
Ordóñez RM Zampini IC Rodríguez F Cattaneo F Sayago JE Isla MI 《Journal of agricultural and food chemistry》2011,59(16):8655-8660
In this study, antioxidant activities in free-radical-mediated oxidative systems and the genotoxic/antigenotoxic effects of two proteins with molecular mass around 17 kDa, purified from Solanum betaceum fruits (cyphomine) and Solanum tuberosum tubers (solamarine), were investigated. Both proteins inhibited uric acid formation with IC(50) values between 55 and 60 μg/mL, and both proteins were able to reduce oxidative damage by scavenging hydroxyl radicals and superoxide anion in a dose-dependent manner. Furthermore, the DPPH? reduction assay showed SC(50) values of 55-73 μg/mL. Cyphomine and solamarine were able to retain their antioxidant activity after heat treatment at 80 °C for 15 min. Allium cepa and Salmonella /microsome assays showed no genotoxic and mutagenic effects. Solamarine showed an antimutagenic effect against a direct mutagen (4-nitro-o-phenylenediamine). Consequently, the present study showed that the investigated proteins are promising ingredients for the development of functional foods with a beneficial impact on human health and an important source for the production of bioactive peptides. 相似文献
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6.
Isla A. Browning 《Potato Research》1995,38(3):281-289
Summary A comparison of reactions of potato cultivars toS. endobioticum indicated that the degree of susceptibility observed in laboratory tests correlated well with the reaction of cultivars in
field tests. Some cultivars found to be less resistant (Resistance Grade 2) in laboratory tests produced winter spores in
the field test, and 10% of those derived from cv. Ausonia germinated in distilled water. Compost from the field plot was estimated
to contain 14–18 apparently viable spores/g. and this resulted in 100% infection of the highly susceptible cv. Arran Chief.
The implications of these findings for descheduling sites previously scheduled due to wart infestation are discussed. 相似文献
7.
Isla MI Paredes-Guzman JF Nieva-Moreno MI Koo H Park YK 《Journal of agricultural and food chemistry》2005,53(4):1166-1172
Twenty-five samples of propolis were collected from seven different regions in northern Argentina; ethanolic extracts of propolis were prepared from all samples, and the respective samples were examined for UV absorption spectra, RPHPTLC, RPHPLC, antimicrobial activity, antiradical activity, and total phenolic content. It was found that 16 of the 25 samples showed a phenolic profile similar to that found in samples from southern Brazil and corresponding to poplar-based propolis and that the rest of the samples showed a different profile and higher antimicrobial and antiradical activities. 相似文献
8.
Unproductive saline and waterlogged (WT) wastelands could be beneficially transformed into agroforestry systems using trees tolerant to these stresses. We studied the salinity and waterlogging tolerance of five Australian tree species (Acacia salicina, Casuarina glauca, Casuarina obesa, Eucalyptus camaldulensis and Eucalyptus occidentalis) during seedling stage and their relationships with root and leaf ion concentrations. 8-month old plants were exposed for 5 months to five irrigation water salinity treatments (EC values between 2 and 22 dS m?1) and two waterlogging treatments (drained or WT). The salinity tolerance of the five species was high, although decreased in WT conditions. Irrespective of salinity, the two Casuarina species were more tolerant and the other three species were less tolerant to WT than drained conditions. In all species, salinity and waterlogging increased leaf Cl? and Na+ and decreased leaf Ca2+, but not leaf K+. Root Cl? and Na+ increased with salinity but not with waterlogging. Salinity tolerance was negatively correlated with Cl? and Na+ leaf accumulation rates per unit increase in salinity. Waterlogging reduced the ability of the seedlings to exclude Cl? and Na+ from the leaves. The two most salt tolerant Casuarina species under both drained and WT conditions showed the highest leaf Cl? and Na+ exclusion and the highest root Cl? and Na+ accumulation, suggesting that sequestration of these toxic ions in their roots was a significant salt-tolerant mechanism. Revegetation of saline and WT wastelands with these tolerant Casuarina species could be profitably used for biomass, biofuel and renewable energy production. 相似文献
9.
Isla Arcaro Berit L. Fischer Kara M. Lascola Stuart C. Clark-Price 《Veterinary anaesthesia and analgesia》2017,44(1):70-76
Objective
To investigate the effects of intravenous (IV) administration of terbutaline on PaO2, PaCO2, pH, heart rate (HR) and arterial pressures in healthy, laterally recumbent horses breathing ambient air under total intravenous anesthesia (TIVA).Study design
Prospective experimental study.Animals
Eight healthy adult horses were enrolled. Six horses, four mares and two geldings weighing 433-624 kg, completed the study.Methods
Horses were sedated with xylazine (1.0 mg kg?1) IV for placement of arterial and venous catheters. Anesthesia was induced with midazolam (0.1 mg kg?1) and ketamine (2.2 mg kg?1) IV and maintained with an IV infusion of guaifenesin (50 mg mL?1), ketamine (2 mg mL?1) and xylazine (0.5 mg mL?1) at 1.9 ± 0.3 mL kg?1 hour?1. Horses were in left lateral recumbency and breathed air spontaneously. Arterial blood was collected for pH and blood gas analysis during xylazine sedation, 15 minutes after induction of anesthesia, immediately before and 5, 15 and 30 minutes after administration of terbutaline (2 μg kg?1), and when the horse was standing after recovery from anesthesia. HR, systolic (SAP), mean (MAP) and diastolic (DAP) arterial pressures were recorded at 5 minute intervals during anesthesia. Normal data were analyzed with anova and non-normal data were analyzed with a Friedman test with a p < 0.05 considered significant.Results
The mean PaO2 decreased from baseline to <60 mmHg (8.0 kPa) during anesthesia (p < 0.0001) and did not improve after administration of terbutaline. After terbutaline administration, HR increased (p = 0.002), and SAP, MAP and DAP decreased (p < 0.001) with the greatest changes occurring immediately after terbutaline administration.Conclusions and clinical relevance
Terbutaline (2 μg kg?1) IV did not improve PaO2 and was associated with adverse cardiovascular effects during TIVA in healthy, laterally recumbent horses breathing air. 相似文献10.