Activity of dehydrogenases in clay soil exposed to quaternary ammonium salts with iodine anion

The aim of the research was to compare the effects of four to quaternary ammonium salts (QAS) with iodine anion: tetramethylammonium iodine [TMA][I], tetraethylammonium iodine [TEA][I], tetrapropylammonium iodine [TEA][I], tetrabutylammonium iodine [TBA][I]. The experiment was carried out on sandy clay loam samples with organic carbon content of 33.82 g·kg-1, and pH in 1 M KCl 7.13. QAS were added to soil at the dosages of: 0, 10, 100, and 1000 mg·kg-1. Activity of dehydrogenases was assayed on days: 1, 14, 35, and 70. Obtained results have shown that the soil treatment with quaternary ammonium salts with iodine anion caused decrease in activity of dehydrogenases. This inhibition increased with increase of QAS dosages, and increase with alkyl chains in cations. Analysis of variance η2 indicated, that type of QAS had the biggest impact on formation of activity of dehydrogenases in soil

EFFECTS OF GLYPHOSATE AMMONIUM SALT ON THE BIOAVAILABLE PHOSPHORUS CONTENT AND THE ACTIVITY OF SELECTED PHOSPHATASES IN LOAMY SAND

The aim of this study was to determine the effects of glyphosatę ammonium salt on the activity of some enzymes involved in the metabolism of phosphorus in the soil: acid phosphomonoeaterase (EC 3.1.3.2), alkaline phosphomonoeaterase (EC 3.1.3.1), phosphotrieaterase (EC 3.1.5.1), inorganic pyrophosphatase (EC 3.1.6.1), and a phosphorus content in a form available to plants. The experiment was carried out on loamy sand samples with organic carbon content 8.7 g kg-1. Into soil samples the aqueous solutions of Avans Premium 360 SC (360 g glyphosate ammonium salt in 1 dm3) were added. The amount of introduced glyphosate ammonium salt was 0 (control), 1, 10, 50 and 100 mg·kg-1, on days 0 (1 hour after glyphosate application), 7, 14, 28 and 56 measured parameters were determined spectrophotometrically. The obtained results showed that the application of glyphosate ammonium salt resulted in changes of available phosphorus content and the activity of enzymes involved in the metabolism of this element in loamy sand. The effects glyphosate ammonium salt dosage and effect of day of experiment were ambiguous. Among the determined parameters the most sensitive to the presence of the glyphosate ammonium was alkaline phosphomonoesterase

The role of anion in the impact of tetraethylammonium salts on soil phosphatase activities

Quaternary ammonium salts (QAS) are increasingly commonly used in the chemical industry. The diverse usage of these compounds results in high possibility of their penetration to the environment. The aim of this study was to compare the effect of three salts with tetraethylammonium cation with different anions such as chloride [TEA][Cl], bromide [TEA][Br], and iodine [TEA][I] on the activity of phosphatases in loamy sand. Organic carbon and total nitrogen content in the soil were 8.71 and 0.97 g·kg-1, respectively. The salts were applied to soil at doses of 0, 0.05, 0.50, and 5.00 mmol·kg-1. The samples were adjusted to 60% maximum water holding capacity, and they were incubated at a temperature of 20°C. Activities of acid phosphomonoesterase, alkaline phopshomonoesterase, phosphotriesterase, and inorganic pyrophosphatase were assayed on day 1, 7, 14, 28, 56, and 112. The obtained results demonstrated that the presence of [TEA] in the soil at the low dose (0.05 mmol·kg-1) may stimulate the activity of soil phosphatases. Higher doses of the soil had mostly inhibitory effect on phosphatases activity. Among the determined enzymes, phosphomonoesterases were the most sensitive to salts containing [TEA] cation. A considerable contribution of the anion type on the formation of activity of the determined enzymes of phosphorus compound changes. The strongest effect characterized tetraethylammonium bromide [TEA][Br]

Late glacial and Holocene paleoceanography of the central Nordic Seas

Five sediment cores of millennial to multicentennial resolution from the Greenland and Lofoten basins, central Nordic Seas, were analyzed for planktic foraminiferal fauna, planktic and benthic stable oxygen and carbon isotopes, and ice-rafted debris. The Nordic Seas are an important region for the global oceanic system because they constitute the main surface and the only deep water connection between the Artic and North Atlantic oceans. They are also a crucial area for deepwater formation. However, due to a lack of high resolution sediment records the paleoceanography of their central part has been poorly investigated in close detail yet. The results in this report show that on a larger spatial and temporal scale the oceanographic evolution of the Nordic Seas is governed mainly by orbital forcing, but other processes can play an equally important role in shorter-scale, more local changes. The most important of these factors are the intensity of Polar and Atlantic waters inflow, the influence of freshwater discharges, sea-ice processes and deep convection. The circum-Nordic Seas marine-based ice sheets collapsed 18,000-16,000 years before present, releasing large amounts of icebergs and freshwater, which affected the overturning circulation and contributed to the Heinrich stadial 1. Between 12,800 and 11,700 years before present the central Nordic Seas were affected by the last major freshwater outburst related with the Younger Dryas. Most likely it entered the area through the Fram Strait, suggesting an Arctic origin for the trigger of this cold event. The Holocene Thermal Maximum in the central Nordic Seas was delayed compared to their eastern part and stretched well into the middle Holocene. The deep convection, developing in the Greenland Basin since the early Holocene, reached its maximum intensity 7,000-6,000 years before present. Neoglacial cooling increased the stratification of the water column and around 3,000 years before present it led to a drop in the deepwater production rate. Ca. 2,000 years before present the subsurface water layer in the central Nordic Seas was warmed by enhanced Atlantic Water inflow to a level comparable with the Holocene Thermal Maximum

Spätglazial und Holozän Paläozeanographie des zentralen Europäischen Nordmeers

Five sediment cores of millennial to multicentennial resolution from the Greenland and Lofoten basins, central Nordic Seas, were analyzed for planktic foraminiferal fauna, planktic and benthic stable oxygen and carbon isotopes, and ice-rafted debris. The Nordic Seas are an important region for the global oceanic system because they constitute the main surface and the only deep water connection between the Artic and North Atlantic oceans. They are also a crucial area for deepwater formation. However, due to a lack of high resolution sediment records the paleoceanography of their central part has been poorly investigated in close detail yet. The results in this report show that on a larger spatial and temporal scale the oceanographic evolution of the Nordic Seas is governed mainly by orbital forcing, but other processes can play an equally important role in shorter-scale, more local changes. The most important of these factors are the intensity of Polar and Atlantic waters inflow, the influence of freshwater discharges, sea-ice processes and deep convection. The circum-Nordic Seas marine-based ice sheets collapsed 18,000-16,000 years before present, releasing large amounts of icebergs and freshwater, which affected the overturning circulation and contributed to the Heinrich stadial 1. Between 12,800 and 11,700 years before present the central Nordic Seas were affected by the last major freshwater outburst related with the Younger Dryas. Most likely it entered the area through the Fram Strait, suggesting an Arctic origin for the trigger of this cold event. The Holocene Thermal Maximum in the central Nordic Seas was delayed compared to their eastern part and stretched well into the middle Holocene. The deep convection, developing in the Greenland Basin since the early Holocene, reached its maximum intensity 7,000-6,000 years before present. Neoglacial cooling increased the stratification of the water column and around 3,000 years before present it led to a drop in the deepwater production rate. Ca. 2,000 years before present the subsurface water layer in the central Nordic Seas was warmed by enhanced Atlantic Water inflow to a level comparable with the Holocene Thermal Maximum.An fünf Sedimentkernen aus dem Grönlandbecken und dem Lofotenbecken (zentrales Europäisches Nordmeer) wurden die planktischen Foraminiferen, planktische und benthische stabile Sauerstoff- und Kohlenstoffisotope und eistransportiertes Material mit einer zeitlichen Auflösung von Jahrhunderten bis Jahrtausenden untersucht. Das Europäische Nordmeer ist eine wichtige Region für das globale Ozeanzirkulationssystem, weil es die wichtigste bzw. einzige Verbindung für den Austausch von Oberflächen- und Tiefenwasser zwischen dem Arktischen und dem Atlantischen Ozean darstellt. Es ist auch ein äußerst wichtiges Gebiet für die Tiefwasserbildung im Weltozean. Wegen nur weniger vorhandener zeitlich hochauflösender Sedimentkerne ist der zentrale Teil des Europäischen Nordmeeres bisher aber relativ unvollkommen untersucht. Die Ergebnisse in dieser Arbeit zeigen, dass die ozeanographische Entwicklung im Arbeitsgebiet großräumlich und auf längeren Zeitskalen vor allem durch orbitale Veränderungen beeinflusst wird. Andere Faktoren können jedoch regional und auf kürzeren Zeitskalen eine ebenso wichtige Rolle spielen. Die wichtigsten dieser Faktoren sind die Intensität der Advektion von polaren und atlantischen Wassermassen, der Einstrom von Süßwasser, sowie Prozesse in Zusammenhang mit der Tiefenwassererneuerung und der Bildung von Meereis. Die rund um das Europäische Nordmeer existierenden marinen Eisschelfe kollabierten ca. 18,000-16,000 Jahre vor heute (J. v. h.). Sie setzten große Mengen von Eisbergen und Süßwasser frei, die die thermohaline Zirkulation beeinflussten und zur Entstehung des Heinrich-Stadials 1 beigetrugen. Zwischen 12.800 und 11.700 J. v. h. wurde das zentrale Europäische Nordmeer vom letzten großen Süßwasserausstoß betroffen, der mit der Jüngeren Dryas assoziiert war. Wahrscheinlich erreichte das Süßwasser das Europäische Nordmeer durch die Framstraße, was auf einen arktischen Ursprung für den Auslöser dieser kalten Klimaphase hindeutet. Das holozäne Temperaturmaximum (HTM) im zentralen Europäischen Nordmeer begann im Vergleich zu seinem östlichen Teil etwas verzögert und zog sich bis ins mittleren Holozän hinein. Die Tiefenwassererneuerung, die sich im Grönlandbecken seit dem frühen Holozän entwickelte, erreichte ihre maximale Intensität ca. 7,000-6,000 J. v. h. Die neoglaziale Kühlung verstärkte die Schichtung der Wassersäule und führte ca. 3.000 J. v. h. zu einer Verringerung in der Tiefwasserproduktionsrate. Ab ca. 2000 J. v. h. zeigen die Daten eine Erwärmung der oberflächennahen Schichten im zentralen Europäischen Nordmeer ähnlich wie im HTM an, was auf einen erneuten verstärkten Atlantikwasserzustrom deutet

The Holocene Thermal Maximum in the Greenland Sea and Fram Strait : temporal and spatial variability

The Holocene Thermal Maximum (HTM) is a distinct time interval in the early Holocene when strong advection of Atlantic Water to the northern Nordic Seas led to the development of conditions favorable for plankton growth due to limited sea ice coverage. Here we present a synthesis of records from the northern and western part of this area, reaching from the SW Greenland Sea (73°N) to the Yermak Plateau (81°N) and revealing temporal and spatial differences in HTM development. High-resolution radiocarbon dating enables us to constrain the timing of the HTM on (sub)millennial scale resolution. In the Fram Strait and on the Yermak Plateau, rapidly increasing subpolar foraminiferal amounts in the sediments and calculated fluxes indicate the arrival of subsurface warm and saline Atlantic Water at 11-10.5 ka. Depending on the temporal resolution, the records show that the maximum influx was terminated already 2000 years later (9-8 ka), contemporaneous to the short period of maximum sea surface temperatures (cf. Risebrobakken et al., 2011, Paleoceanography v. 26). In the northernmost Greenland Sea, low-resolution records show that the timing may have been similar here. A new submilliennial-scale record from the Vesterisbanken (73°N) in the Greenland Sea, however, reveals a somewhat different picture for this more southern area, affected by the Greenland Gyre. A reduction in annual ice coverage, as indicated by increasing total amounts of planktic foraminifers in the sediment, also occurred between 11 and 10 ka, but the maximum Atlantic Water advection came later (9 ka) and lasted until 6 ka. Apparently, the SW Greenland Sea site records the history of Atlantic Water in the Greenland Gyre that decoupled from the northward flowing Norwegian Atlantic Current/Westspitsbergen Current south of the Fram Strait and supplied relatively high amounts of heat to the subsurface Greenland Sea well into the middle Holocene. At that time, the more northerly sites had already experienced a substantial cooling and an increase in ice coverage, probably induced by a stronger sea ice production in the Arctic Ocean than in the Early Holocene

Combined effect of low-molecular-weight organic acids and creosote on phosphatase activities in sandy soil

This paper assesses the impact of creosote and low-molecular-weight organic acids (LMWOAs) on the activity of acid phosphomonoesterase, alkaline phosphomonoesterase, phosphotriesterase, and inorganic pyrophosphatase in soil. The experiment was carried out on loamy sand samples with organic carbon content of 8.71 g·kg-1, with the following variable factors: dosages of creosote: 0, 0.5%, and 2.5%; type of LMWOAs: oxalic acid, tartaric acid, and citric acid in the amount of 50 mmol·kg-1of soil; days of experiment: 1, 7, 14, 28, 56, 112. Obtained results showed that contamination with creosote caused decrease in the activity of soil phosphatases. The observed effect did not always increase with increase in the dosage of the pollutant. Among the assayed phosphatases, the biggest changes were noted in the activity of phosphomonoesterases. Application of LMWOAs to contaminated soil mainly effected the inhibition of phosphatase, especially the activity of acid phosphomonoesterase. Comparison of the effects of LMWOAs showed that the citric acid was the least toxic to soil phosphatases

Paleoceanography of the Northwestern Greenland Sea and Return Atlantic Current evolution, 35–4 kyr BP

The flow of the Atlantic Water (AW) via the Return Atlantic Current (RAC) regulates the oceanographical conditions in the Northwestern (NW) Greenland Sea in the Fram Strait. As the intensity of the RAC might significantly influence both deep-water formation in the area and the stability of the Northeast Greenland Ice Sheet (NE GIS), knowledge of its variability in the past is important. Here we present a reconstruction of the paleoceanographic forcing of the AW on climatic conditions and associated environmental changes in the NW Greenland Sea by means of foraminiferal assemblages, stable (oxygen and carbon) isotopes, and various sedimentological parameters from sediment core GR02-GC retrieved from NE Greenland continental slope (1170 m water depth). Our data indicate an almost continuous presence of AW in the NW Greenland Sea during the last 35 kyr BP. Two peaks of low planktic δ18O values at ~34.5 and 33 kyr BP are interpreted as meltwater signals associated with warm AW-induced melting of the adjacent NE GIS. The NE GIS advanced between 32 and 29 kyr BP, resulting in reduced meltwater influx to the NW Greenland Sea. Increased iceberg calving and melting after 29 kyr BP, were probably linked to surface warming and glacier advance to the shelf-break lasting until 23.5 kyr BP. During the Last Glacial Maximum, the extensive sea ice cover was associated with the presence of subsurface AW at the study site. During the Bølling–Allerød (B/A, ~14.6–12.7 kyr BP) strong melting of glaciers and sea ice was probably caused by the combined effect of the B/A warming and the flow of warm AW. The RAC was weakened during the Younger Dryas (~12.8–11.7 kyr BP), which reduced the advection of warm AW to the NW Greenland Sea. After 11.7 kyr BP, the RAC reached its modern strength, whereas, during the Holocene Thermal Maximum, it reached its maximum strength for the study period. In addition, short-term weakening of AW inflow to the core site was observed, especially at 10.5, 8.5, and 5.8 kyr BP

The morphological and biochemical effects of feeding Hooker’s pitcher with Formica fusca or Calliphora vicina Larvae

The aim of this study was to determine if feeding Hooker’s pitcher (Nepenthes × hookeriana) with blowfly larvae (Calliphora vicina Rob-Desvoidy) or ants (Formica fusca L.) affected the plant’s biometric and biochemical parameters. The research included measurements of length and width of the laminae and pitchers, and the total contents of the ash, assimilation pigments, polyphenols, and flavonoids. These parameters were measured 30 days after the last feeding. This study demonstrated that feeding the plants with blowfly larvae resulted in increases in the lengths and widths of both the laminae and pitchers. Moreover, the laminae had reduced carotenoid content after feeding with blowfly larvae and ants whereas the pitchers of Hooker’s pitcher had increased chlorophyll and carotenoid content after feeding with blowfly larvae. Feeding Hooker’s pitcher plants with blowfly larvae also resulted in a reduction of the total polyphenol content in the laminae whereas the total flavonoid content increased in both the laminae and pitchers of Hooker’s pitcher. Feeding Nepenthes × hookeriana with insects ensures that their nutritional needs are met and leads to pitchers with good physiological condition

Assessment of Napropamide Dissipation and its Effect on Soil Enzymatic Activity

This paper assesses the dissipation of napropamide and its impact on the activity of dehydrogenases, alkaline phosphatase, acid phosphatase, and urease in sandy clay loam. The experiment was carried out on soil samples with organic carbon content of 12.08 g·kg-1, total nitrogen content of 0.97 g·kg-1, and pH 5.24 with the following variable factors: (a) dose of Devrinol 450 SC formation (containing 450 g of napropamide in dm3): 0 (control), 0.5, 1, 2, 4, 8, and 16-fold hold of field dose; (b) day of experiment: 1, 7, 14, 28, 56, and 112. The half-life of napropamide ranged from 33.50 to 71.42 days. The use of napropamide at the dose recommended by the manufacturer and at the dose reduced by half appeared to exhibit low toxicity in relation to enzymes determined. In contrast, the application of elevated napropamide doses decreased the values of biochemical parameters of the soil in most cases. The Pearson correlation coefficients showed statistically significant negative correlation between the content of napropamide residues and the enzymatic activity of the soil