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| Whitby, Hannah; Hollibaugh, James T.; Van Den Berg, Constant M. G.. |
| The concentrations of dissolved copper (Cu-d), copper-binding ligands, thiourea-type thiols, and humic substances (HScu) were measured in estuarine waters adjacent to Sapelo Island, Georgia, USA, on a monthly basis from April to December 2014. Here we present the seasonal cycle of copper speciation within the estuary and compare it to the development of an annually occurring bloom of Ammonia Oxidizing Archaea (AOA), which require copper for many enzymes. Two types of complexing ligands (L-1 and L-2) were found to dominate with mean complex stabilities (log K'(cuL)) of 14.5 and 12.8. Strong complexation resulted in lowering the concentration of free cupric ion (Cu2+) to femtomolar (fM) levels throughout the study and to sub-fM levels during the summer... |
| Tipo: Text |
Palavras-chave: Copper speciation; Cathodic stripping voltammetry; Humic substances; Thiols; Thiourea; Organic ligands; Thaumarchaeota; Ammonia-oxidizing archaea. |
| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00616/72834/72735.pdf |
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| Ikram,R.M.; Tanveer,A.; Ata,Z.; Saqib,M.. |
| The aim of this study was to examine the dormancy behavior of Euphorbia dracunculoides and Astragalus spp., weeds of arid chickpea. The dormancy breaking treatments were: Gibberalic acid (GA3) and Thiourea each at 50, 100, 150, 200, 250, and 300 ppm and Potassium nitrate (KNO3) at 5,000, 10,000, 15,000, 20,000, 25,000, and 30,000 ppm (24 h soaking). Germination (G) percentage and germination energy (GE) of E. dracunculoides was maximum (89 and 22, respectively) at 250 ppm concentration of GA3 and 81.50 and 11.50 at 15000 ppm concentration of KNO3. Thiourea at 250 and 300 ppm resulted in maximum G percentage (51) and GE (25.50) of E. dracunculoides, whereas the G percentage and GE of Astragalus spp. were maximum (28 and 19, respectively) at the lowest... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: GA3; KNO3; Thiourea; Dormancy; E. dracunculoides; Astragalus spp. |
| Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582014000400009 |
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| MUNAWAR,S.; NAEEM,M.; ALI,H.H.; JAMIL,M.; IQBAL,M.; NAZIR,M.Q.; BALAL,R.M.; SAFDAR,M.E.. |
| ABSTRACT Understanding the mechanisms involved in releasing seed dormancy is crucial for effective plant management and renewal of species in the arid zone. Zaleya pentandra is an emerging invasive weed of the arid areas of Pakistan. We investigated the effects of different dormancy breaking treatments on the germination of Z. pentandra seeds. Seeds were treated with hot water (by placing them in boiling water for 5, 15, 30, 60, 90, 120, and 150 min), dry heat (by placing them in a preheated oven at 70 oC for 1, 2, and 4 hours; at 70 oC for 1, 2, 3, and 4 days, and at 200 oC for 5, 10, 15, 30, and 45 min) and stratification (by placing them at 2-5 ºC in a refrigerator for 5, 10, 30, and 60 min; for 3, 6, and 12 hours, and for 1, 2, 4, 8, 15, and 30 days).... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Germination; Scarification; Stratification; Dry heat; Thiourea; Arid zone. |
| Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582015000400623 |
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