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1
Gao, Ya, Bihan Gu, Lingchen Mao, Daofang Zhang, and Hong Tao. "Natural Factors on Heterogenetic Accumulations of PTEs in Sloping Farmland in a Typical Small Mountainous Watershed in Southwest China." Separations 9, no. 6 (June 10, 2022): 149. http://dx.doi.org/10.3390/separations9060149.
Повний текст джерелаАнотація:
High potential toxic element (PTE) concentrations in soils that exceed local regulatory threshold values have been reported in non-polluted mountainous areas worldwide. However, there have been few studies that have comprehensively investigated the contribution of natural factors including the parental material, pedogenesis processes and physiochemical properties of soils on the distribution of PTEs in these soils. Therefore, in this study, we studied the distribution of 13 PTEs in sloping farmland soils collected from a mountainous watershed in Guizhou Province, Southwest China. The contributions of natural influencing factors were analyzed using a geostatistical analysis and a geographic detector method. All of the PTEs were unevenly distributed, especially Sb, and the average contents of V, Cr, Co, Ni, Cu, Zn, As, Mo, Cd, Sb, Tl, Pb and Hg were 57.15, 36.20, 4.61, 12.61, 13.36, 63.50, 11.94, 0.78, 0.37, 6.44, 0.48, 27.42 and 0.36mg/kg, respectively. The proportion of samples with Cd, Hg and As exceeding the screening value of the soil pollution risk of agricultural land in China was 46.7%, 5.9% and 4.4%, respectively. Except for Cd and Pb, the q values of the PTEs calculated from the geographical detector were above 0.05, indicating that altitude changes, which affect the pedogenesis process, have a great impact on the spatial distribution. Stratigraphic factors contributed greatly to the distribution of Co, Ni and Cu, which indicates their similarity in parental material. The combined effect of clay content, topographic factors and agricultural land types had the strongest explanatory power for V, Cr, Mo and Pb. The distributions of As, Sb, Tl and Hg are strongly associated with a potential source of mercury ore, and their accumulation is also enhanced by the adsorption on soil clay. Agricultural As also contributes to its distribution.
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HENDERSON, W. G., L. C. ANDERSON, and C. R. McGIMSEY. "Distinguishing Natural and Archaeological Deposits: Stratigraphy, Taxonomy, and Taphonomy of Holocene Shell-Rich Accumulations from the Louisiana Chenier Plain." PALAIOS 17, no. 2 (April 1, 2002): 192–205. http://dx.doi.org/10.1669/0883-1351(2002)017<0192:dnaads>2.0.co;2.
Повний текст джерела
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Wen, Baole, Daria Akhbari, Li Zhang, and Marc A. Hesse. "Convective carbon dioxide dissolution in a closed porous medium at low pressure." Journal of Fluid Mechanics 854 (August 31, 2018): 56–87. http://dx.doi.org/10.1017/jfm.2018.622.
Повний текст джерелаАнотація:
Motivated by the persistence of natural carbon dioxide ($\text{CO}_{2}$) fields, we investigate the convective dissolution of $\text{CO}_{2}$ at low pressure (below 1 MPa) in a closed system, where the pressure in the gas declines as convection proceeds. This introduces a negative feedback that reduces the convective dissolution rate even before the brine becomes saturated. We analyse the case of an ideal gas with a solubility given by Henry’s law, in the limits of very low and very high Rayleigh numbers. The equilibrium state in this system is determined by the dimensionless dissolution capacity, $\unicode[STIX]{x1D6F1}$, which gives the fraction of the gas that can be dissolved into the underlying brine. Analytic approximations of the pure diffusion problem with $\unicode[STIX]{x1D6F1}>0$ show that the diffusive base state is no longer self-similar and that diffusive mass transfer declines rapidly with time. Direct numerical simulations at high Rayleigh numbers show that no constant flux regime exists for $\unicode[STIX]{x1D6F1}>0$; nevertheless, the quantity $F/C_{s}^{2}$ remains constant, where $F$ is the dissolution flux and $C_{s}$ is the dissolved concentration at the top of the domain. Simple mathematical models are developed to predict the evolution of $C_{s}$ and $F$ for high-Rayleigh-number convection in a closed system. The negative feedback that limits convection in closed systems may explain the persistence of natural $\text{CO}_{2}$ accumulations over millennial time scales.
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Tebbens, L. A., A. Veldkamp, and S. B. Kroonenberg. "Natural compositional variation of the river Meuse (Maas) suspended load: a 13 ka bulk geochemical record from the upper Kreftenheye and Betuwe Formations in northern Limburg." Netherlands Journal of Geosciences - Geologie en Mijnbouw 79, no. 4 (December 2000): 391–409. http://dx.doi.org/10.1017/s0016774600021909.
Повний текст джерелаАнотація:
AbstractUnambiguously pristine and largely unpolluted sediments from the Late Weichselian and Holocene infillings of the Meuse residual channels in northern Limburg (the Netherlands) have been sampled to determine the natural compositional variation of the river’s suspended load.Bulk geochemical and granulometric analyses demonstrate that about 70% of the variation can be ascribed to hydrodynamic mineral sorting. Clay- and fine silt-sized phyllosilicates are the most important deterministic features, hosting the bulk of AI2O3, TiO2, K2O, MgO and trace element variability (notably Ba, Cr, Ga, Rb and V). Quartz is abundant in the fine and coarse sand fractions. Na2O and the Zr-Nb-Nd-Y quartet relate to albitic feldspars and heavy minerals, respectively, in the coarse silt fraction. The granulometry should therefore be quantified if geochemical baseline data for a particular geological unit or region are drawn up and for the evaluation of potentially polluted sediments.Although provenance has not changed, the composition of Meuse sediments cannot be considered constant over a time frame of 1000–10,000 years, due to climatic change. Weathering of phyllosilicates in both interstadial and interglacial soil environments and changing relative source-area contributions alter the detrital clay-mineral supply to raise the AI2O3 and lower the K2O and MgO contents in Holocene Meuse sediments. Early diagenetic siderite and vivianite formation in gyttjas causes relative accumulations of Fe2O3, MnO, P2O5, Co, Ni and notably Zn above the phyllosilicate background values. These accumulations are natural and show that sediments with elevated trace metal contents are not necessarily polluted. Very early atmospheric pollution in relation to ore mining and smelting activities in the Roman era, however, probably caused elevated Pb contents in Subatlantic humic clays and peat samples, long before the historic pollution of the Industrial Revolution started.The A12O3, Fe2O3 and CaO contents are used to predict the trace-element values as a function of sample granulometry, siderite/vivianite and lime content, respectively. As such, they can provide a sound basis for environmental researchers to determine baseline values of heavy metals in bulk samples of fine-grained fluvial sediments.
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Zeng, Yongyao, and Bo Zhou. "Variation Feature, Pollution Risk Assessment, and Source Analysis of Heavy Metals in Lanzhou City, Northwestern China." Geofluids 2022 (July 18, 2022): 1–15. http://dx.doi.org/10.1155/2022/5165194.
Повний текст джерелаАнотація:
Lanzhou is located in the northwest of China and is famous for its petrochemical and heavy industries of China. The city has suffered long-term pollution of heavy metals in recent years. Significant efforts, such as tax subsidies for new energy vehicles and treating solid waste, have been launched by the Lanzhou municipal government to address the pollution of heavy metals since 2010. What is the current status of heavy metal pollution in Lanzhou? In this study, the concentrations of 12 heavy metals (V, Cr, Mn, Co, Ni, Cu, Zn, As, Mo, Cd, Sb, and Pb) were tested from 20 sediment samples. Mn, Zn, V, and Cr are the predominant heavy metals, with mean concentrations of 534.65, 65.85, 56.29, and 36.05 mg/kg; Ni, Cu, Pb, Co, and As are in moderate amounts, with mean concentrations of 25.2, 21.5, 16.7, 9.87, and 4.86 mg/kg; Mo and Cd have the lowest mean concentrations of 0.54 and 0.15 mg/kg. A low ecological risk is confirmed by two indices, the Hakanson potential ecological risk index ( R I ) and the geoaccumulation index ( I geo ). The R I index has lower E i r values (<40) and R I values (<150), which range from 18.11 to 37.95, with an average value of 25.61. Co, V, Cd, Cu, Zn, As, Cr, Ni, Pb, and Mn metals are classified as an uncontaminated environment (level 0) and a moderately to heavily contaminated environment (level 2-level 3) by I geo values. Seven heavy metals (Pb, Cd, Cr, As, Cu, Zn, and Ni) in Lanzhou are the relatively lowest amount in the 5 cities in China. The changing trends of heavy metal concentrations firstly increase and then decrease gradually from 2005 to 2022. The time turning point of concentration shrinking occurred in approximately 2014, which is in response to the increased efforts of addressing the pollution launched by the Lanzhou municipal government since 2010. Source analysis by Pearson’s correlation and principal component analysis revealed that the accumulation of Mo metal was caused by the enrichment of MnO2 in the oxidic condition; the accumulations of Cu, Co, Ni, Mn, Cr, Zn, Cd, and Pb metals are influenced by natural sources and human activities (vehicle exhaust and industrial pollution), respectively.
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Yilmaz, Aysenur, Sibel Yıldız, Ahmet Çelik, and Uğur Çevik. "Determination of Heavy Metal and Radioactivity in Agaricus campestris Mushroom Collected from Kahramanmaraş and Erzurum Proviences." Turkish Journal of Agriculture - Food Science and Technology 4, no. 3 (March 31, 2016): 208. http://dx.doi.org/10.24925/turjaf.v4i3.208-215.596.
Повний текст джерелаАнотація:
In this study, radioactivity and heavy metals accumulations in Agaricus campestris mushroom collected from Kahramanmaraş and Erzurum provinces was determined. HPGe gamma detector was used for the determination of radioactivity concentrations. Heavy metal content was measured using a ICP-MS. As radioactive element; natural (238U, 232Th 40K) and artificial radionuclide (137Cs) concentrations were determined. The values of the committed effective dose were calculated. Same measurements were made in soils. Absorbed dose and excess lifetime cancer risk were calculated. Amount of Mg, Al, Ca, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Cd, Pb206, Pb207 and Pb208 as heavy metals of mushrooms were determined. 238U, 232Th, 40K activity concentrations of mushroom collected from Erzurum was determined as 12.1 ± 0.8, 11.7 ± 0.9, 497.7 ± 17.8 Bq/kg, respectively and 137Cs was not detected by system. 232Th and 40K activity concentrations of mushroom collected from Kahramanmaraş was determined as 13.4 ± 0.5, 134.9 ± 6.3 Bq/kg, respectively, 238U and 137Cs was not detected by system similarly. The value of the committed effective dose collected from Erzurum and Kahramanmaraş were calculated as 75 and 29 μSv respectively and these values were found lower than 290 μSv accepted as world average. Absorbed dose and risk of lifetime cancer for Erzurum was determined as 37.39 nGy/h, 16.5 x 10-5; absorbed dose and excess lifetime cancer risk for Kahramanmaraş was determined as 30.92 nGy/h, 13.3 x 10-5 respectively. Amount of daily intake for each heavy metal was calculated. Radionuclide activity concentrations and accumulations of heavy metal were not founded threaten level to healthy, except from arsenic As (0.025 and 0.039 mg/kg) in mushroom collected from both provinces. They were found a bit higher than upper limit (0.015 mg/kg) in report which is prepared World Health Organization (WHO) and Food and Agriculture Organization of the United Nations (FAO) jointly.
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Kampman, N., A. Maskell, M. J. Bickle, J. P. Evans, M. Schaller, G. Purser, Z. Zhou, et al. "Scientific drilling and downhole fluid sampling of a natural CO<sub>2</sub> reservoir, Green River, Utah." Scientific Drilling 16 (November 5, 2013): 33–43. http://dx.doi.org/10.5194/sd-16-33-2013.
Повний текст джерелаАнотація:
Abstract. A scientific borehole, CO2W55, was drilled into an onshore anticline, near the town of Green River, Utah for the purposes of studying a series of natural CO2 reservoirs. The objective of this research project is to recover core and fluids from natural CO2 accumulations in order to study and understand the long-term consequences of exposure of supercritical CO2, CO2-gas and CO2-charged fluids on geological materials. This will improve our ability to predict the security of future geological CO2 storage sites and the behaviour of CO2 during migration through the overburden. The Green River anticline is thought to contain supercritical reservoirs of CO2 in Permian sandstone and Mississippian-Pennsylvanian carbonate and evaporite formations at depths > 800 m. Migration of CO2 and CO2-charged brine from these deep formations, through the damage zone of two major normal faults in the overburden, feeds a stacked series of shallow reservoirs in Jurassic sandstones from 500 m depth to near surface. The drill-hole was spudded into the footwall of the Little Grand Wash normal fault at the apex of the Green River anticline, near the site of Crystal Geyser, a CO2-driven cold water geyser. The hole was drilled using a CS4002 Truck Mounted Core Drill to a total depth of 322 m and DOSECC’s hybrid coring system was used to continuously recover core. CO2-charged fluids were first encountered at ~ 35 m depth, in the basal sandstones of the Entrada Sandstone, which is open to surface, the fluids being effectively sealed by thin siltstone layers within the sandstone unit. The well penetrated a ~ 17 m thick fault zone within the Carmel Formation, the footwall damage zone of which hosted CO2-charged fluids in open fractures. CO2-rich fluids were encountered throughout the thickness of the Navajo Sandstone. The originally red sandstone and siltstone units, where they are in contact with the CO2-charged fluids, have been bleached by dissolution of hematite grain coatings. Fluid samples were collected from the Navajo Sandstone at formation pressures using a positive displacement wireline sampler, and fluid CO2 content and pH were measured at surface using high pressure apparatus. The results from the fluid sampling show that the Navajo Sandstone is being fed by active inflow of CO2-saturated brines through the fault damage zone; that these brines mix with meteoric fluid flowing laterally into the fault zone; and that the downhole fluid sampling whilst drilling successfully captures this dynamic process.
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Li, Qi, Jinming Zhang, Wen Ge, Peng Sun, Yafen Han, Husen Qiu, and Shoubiao Zhou. "Geochemical Baseline Establishment and Source-Oriented Ecological Risk Assessment of Heavy Metals in Lime Concretion Black Soil from a Typical Agricultural Area." International Journal of Environmental Research and Public Health 18, no. 13 (June 26, 2021): 6859. http://dx.doi.org/10.3390/ijerph18136859.
Повний текст джерелаАнотація:
To accurately assess the potential ecological risk posed by heavy metals in lime concretion black soil and quantify the risk contributions from different sources, an investigation of 217 surface soil samples and 56 subsoil samples was performed in the southern part of Suzhou City. Geochemical baseline values of soil heavy metals (Cr, Zn, Pb, Ni, Hg, Cu, Cd, As, Mn and Co) in the study area were calculated as 53.6, 61.5, 19.8, 27.6, 0.08, 18.4, 0.13, 12.9, 416.1 and 11.0 mg/kg, respectively, by using reference metal normalization and cumulative frequency curve methods. Subsequently, four potential sources of soil heavy metals were identified by the positive matrix factorization. Finally, the potential ecological risks arising from the identified sources were determined by the integrated model of positive matrix factorization and Hakanson potential ecological risk index. Results showed that the ecological risk posed by soil heavy metals in the study area ranged from low to moderate level. Hg and Cd were the two largest risk contributors, supplying 36.0% and 30.3% of total risk value. The origin of heavy metals in the soils is mostly related to four sources including agricultural activities, natural dispersion, coal consumption and traffic pollution. Source apportionment of the potential ecological risks revealed that the dominant risk source in the study area was natural dispersion (42.0%), followed by coal related industries (26.5%), agricultural activities (20.4%) and traffic pollution (11.1%). This work gives a clear baseline information of the heavy metal accumulations in lime concretion black soil and provides a successful case study for the source-oriented ecological risk assessment.
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Punanova, Svetlana. "About characteristic features of naftides in connection with the process of formation of deposits." Georesursy 23, no. 4 (November 30, 2021): 107–15. http://dx.doi.org/10.18599/grs.2021.4.12.
Повний текст джерелаАнотація:
Studies have been carried out to assess the qualitative features of fluids, aimed at identifying the regularities in the differentiation of the properties of naphthides during the formation of hydrocarbon deposits outside anticlinal structures. Due to the exhaustion of hydrocarbon reserves associated with anticlinal traps, the main attention is paid to the composition of fluids confined specifically to non-anticlinal structures – to traps of a combined structure. Physicochemical properties, trace element (TE) composition, phase states of naphthides in deposits affected by hypergenetic or catagenetic processes have been analyzed using specific examples; in regions with a possible additional inflow of hydrocarbons (Romashkino group of fields in the Republic of Tatarstan); in the crystalline basement of sedimentary basins. The results of the analysis make it possible to predict the characteristic features of fluids in traps of various types at certain levels of the processes of oil formation, secondary transformation and destruction of accumulations, mainly due to the tectonic regime of the sedimentary basin. With prolonged lateral migration, at great depths with good isolation from surface weathering agents, light oils, depleted in TE, more often of nickel specialization, are found in lithologically and stratigraphically screened traps, and gas condensate accumulations are possible. At shallow depths with poor regional or local seals, heavy, highly viscous hypergene-transformed oils, natural bitumens with high concentrations of industrially significant metals V, Ni, Co, Mo Cd, U were found in traps of pinch-out zones and various types of trap screening. tectonically-screened traps) with a multiphase filling of traps and, at the same time, the influence and inflow of deep ones, i.e. more catagenically transformed fluids, it is possible to detect light oils of the nickel type or gas condensates enriched with elements of “magmatic emanations” – As, Hg, Al, B, rare earth elements. Oils filling combined traps in the crystalline basement within platform oil and gas basins, as a rule, do not differ in their compositional peculiarities in comparison with oils in overlying or adjacent parts of the sedimentary section.
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Łukaszewski, Mariusz. "The application of volume texture extraction to three-dimensional seismic data – lithofacies structures exploration within the Miocene deposits of the Carpathian Foredeep." Geology, Geophysics and Environment 46, no. 4 (January 26, 2021): 301–13. http://dx.doi.org/10.7494/geol.2020.46.4.301.
Повний текст джерелаАнотація:
There are numerous conventional fields of natural gas in the Carpathian Foredeep, and there is also evidence to suggest that unconventional gas accumulations may occur in this region. The different seismic sig-natures of these geological forms, the small scale of amplitude variation, and the large amount of data make the process of geological interpretation extremely time-consuming. Moreover, the dispersed nature of information in a large block of seismic data increasingly requires automatic, self-learning cognitive processes. Recent developments with Machine Learning have added new capabilities to seismic interpretation, especially to multi-attribute seismic analysis. Each case requires a proper selection of attributes. In this paper, the Grey Level Co-occurrence Matrix method is presented and its two texture attributes Energy and Entropy. Haralick’s two texture parameters were applied to an advanced interpretation of the interval of Miocene deposits in order to discover the subtle geological features hidden between the seismic traces. As a result, a submarine-slope channel system was delineated leading to the discovery of unknown earlier relationships between gas boreholes and the geological environment. The Miocene deposits filling the Carpathian Foredeep, due to their lithological and facies diversity, provide excellent conditions for testing and implementing Machine Learning techniques. The presented texture attributes are the desired input components for self-learning systems for seismic facies classification.
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Mallia, Vittoria, Lada Ivanova, Gunnar S. Eriksen, Emma Harper, Lisa Connolly, and Silvio Uhlig. "Investigation of In Vitro Endocrine Activities of Microcystis and Planktothrix Cyanobacterial Strains." Toxins 12, no. 4 (April 4, 2020): 228. http://dx.doi.org/10.3390/toxins12040228.
Повний текст джерелаАнотація:
Cyanobacteria are cosmopolitan photosynthetic prokaryotes that can form dense accumulations in aquatic environments. They are able to produce many bioactive metabolites, some of which are potentially endocrine disrupting compounds, i.e., compounds that interfere with the hormonal systems of animals and humans. Endocrine disruptors represent potential risks to both environmental and human health, making them a global challenge. The aim of this study was to investigate the potential endocrine disrupting activities with emphasis on estrogenic effects of extracts from cultures of Microcystis or Planktothrix species. We also assessed the possible role of microcystins, some of the most studied cyanobacterial toxins, and thus included both microcystin-producing and non-producing strains. Extracts from 26 cyanobacterial cultures were initially screened in estrogen-, androgen-, and glucocorticoid-responsive reporter-gene assays (RGAs) in order to identify endocrine disruption at the level of nuclear receptor transcriptional activity. Extracts from selected strains were tested repeatedly in the estrogen-responsive RGAs, but the observed estrogen agonist and antagonist activity was minor and similar to that of the cyanobacteria growth medium control. We thus focused on another, non-receptor mediated mechanism of action, and studied the 17β-estradiol (natural estrogen hormone) biotransformation in human liver microsomes in the presence or absence of microcystin-LR (MC-LR), or an extract from the MC-LR producing M. aeruginosa PCC7806 strain. Our results show a modulating effect on the estradiol biotransformation. Thus, while 2-hydroxylation was significantly decreased following co-incubation of 17β-estradiol with MC-LR or M. aeruginosa PCC7806 extract, the relative concentration of estrone was increased.
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Papadopoulos, Argyrios, Ioannis T. Tzifas, and Harilaos Tsikos. "The Potential for REE and Associated Critical Metals in Coastal Sand (Placer) Deposits of Greece: A Review." Minerals 9, no. 8 (July 31, 2019): 469. http://dx.doi.org/10.3390/min9080469.
Повний текст джерелаАнотація:
The rare earth elements (REEs) are characterized by the European Union (EU) as critical raw materials with a significant risk of supply because of their broad utility in both traditional and emerging technological applications. The growing demand for REE has caused a flurry in the search for new REE deposits in Europe and elsewhere in the world, and is also linked to rising exploitation efforts in a variety of geological settings. To this end, Greece appears to be a promising candidate to become a leading EU country in terms of REE by virtue of its natural endowment in sedimentary heavy mineral deposits (placers) along its long coastline. The present review focuses on the distribution, abundance, and bulk geochemistry of REEs and other critical metals (Ta, Nb, Co) associated with placer deposits of Greece, and specifically with geologically young heavy mineral sand accumulations developed proximal to felsic plutonic source rocks. These deposits are also enriched in the actinides uranium (U) and thorium (Th), as both of these metals are typically associated with REE-rich minerals such as xenotime, monazite, thorite, allanite, and zircon. Previous studies have employed a variety of analytical techniques down to nano-meter scale with the aim to elucidate the mineralogy and distribution of REE and associated actinides in Greek beach placers. In view of this mineralogically-intensive background, the present review focuses chiefly on bulk geochemical characteristics of the same deposits and the variations thereof between two major geographical regions (northern Greece, southern Aegean) and across individual placer occurrences within them. In this framework, we present comprehensive compositional comparisons between the different deposits, highlighting the geological sub-environments wherein they occur, their distinctive sources and geochemical signatures, and their potential economic significance in terms of REE and other critical metal enrichments where applicable.
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Marcinkonis, Saulius, Bronislavas Karmaza, and Colin A. Booth. "GEOCHEMISTRY OF FRESHWATER CALCAREOUS SEDIMENTS AND LONGEVITY IMPACTS OF THEIR APPLICATION TO ACIDIC SOILS OF EASTERN LITHUANIA / GEOCHEMINĖ GĖLAVANDENIŲ KALKINGŲJŲ NUOSĖDŲ SUDĖTIES VARIACIJA IR JŲ NAUDOJIMO PALIKIMAS RŪGŠTIEMS RYTŲ LIETUVOS DIRVOŽEMIAMS." Journal of Environmental Engineering and Landscape Management 20, no. 4 (November 22, 2012): 285–91. http://dx.doi.org/10.3846/16486897.2012.656646.
Повний текст джерелаАнотація:
Numerous investigations on the quaternary depositions of natural calcareous sediments and their use for soil conditioning have been carried-out in the Baltic region. Locally sourced freshwater limestone were formerly introduced (1950s) for soil liming, due to the absence or limited availability of appropriate industrial materials. Nowadays, with a greater awareness and understanding of the CO2 issues surrounding the production of industrial lime (intensively heated during manufacture), together with increasing costs of its production and transport, attention has returned to previous approaches. The main aim of this study was the identification of geological distribution peculiarities of freshwater limestone depositions, spatial and vertical geochemical variation and modelling of their previous agricultural use in acid soils regions. Geochemical composition data of local lake limestone has been lacking in Lithuania. Studies reveal that the quality parameters of sediments mostly align with the minimum for standard lime requirements (EN ISO 12945:2008), but materials are geochemically diverse even between layers of the same deposit. Tests show calcareous materials are especially rich in total manganese (3500 ppm) and slightly lower was total barium concentrations (490 ppm). Just a few mg kg−1 less were total concentrations of silver, boron, cobalt, chromium, copper, gallium, nickel, lead and vanadium. Former use of these sediments for liming purposes with regard to the national hygiene norm (HN 60:2004) controlled elements disclaim direct risks of soil pollution by higher heavy metals and rare elements accumulation. Previous liming studies indicate natural limes offer slow acting degradability compared to industrial products (dust limestone) and longer lasting liming effect. However, heavy metals and rare elements applied to soils are locked in topsoil (diffusion is mainly limited to depth of soil tillage). Unfortunately, cessation of liming and accelerated soil acidification promotes increased element mobility, which raises the risk of higher accumulations in crops, and their transfer to the food chain and/or their transport to groundwater. Santrauka Baltijos jūros regione atlikta nemažai tyrimų, kurių sudėtinė dalis – kalkingųjų kvartero nuosėdų tyrimai ir jų naudojimas dirvai gerinti. Gėlavandenės klintys buvo naudojamos dirvožemiams kalkinti trūkstant pramoninių kalkinių medžiagų. Šiuo metu jomis vėl domimasi, nes jos leidžia išvengti CO2 emisijų, susidarančių gaminant pramonines kalkines medžiagas (kaitinant klintis), jų naudojimas yra ekonomiškai patrauklus. Pagrindinis atliktų tyrimų tikslas – nustatyti geologinio paskirstymo ypatumus gėlavandenėse kalkingosiose nuosėdose, horizontalųjį bei vertikalųjį geocheminį pasiskirstymą ir ankstesnio šių medžiagų naudojimo žemės ūkio paskirties rūgščių dirvožemių regionuose išliekamąjį poveikį. Geocheminė gėlavandenių klinčių sudėtis anksčiau Lietuvoje nebuvo tirta. Atliekant tyrimus nustatyta, kad kalkingosios nuosėdos dažniausiai atitiko minimalių standartinių kalkinių medžiagų reikalavimų kokybės rodiklius (EN ISO 12945:2008), bet geocheminė šių medžiagų sudėtis yra labai įvairi net skirtinguose to paties klodo sluoksniuose. Buvo nustatyta, kad išanalizuotose kalkingosiose nuosėdose yra ypač daug suminio Mn (3500 ppm) ir šiek tiek mažesnė Ba koncentracija (490 ppm). Tik keli mg kg−1 ar mažiau buvo rasta suminių Ag, B, Co, Cr, Cu, Ga, Ni, Pb ir V. Modeliuojant buvusį šių nuosėdų naudojimą kalkinimo tikslais, vertinant pagal higienos normoje (HN) kontroliuojamų elementų koncentracijas, paneigtas tiesioginis dirvožemio taršos pavojus sunkiaisiais metalais ir retaisiais elementais. Šiomis medžiagomis kalkintuose dirvožemiuose sunkiųjų metalų ir retųjų elementų atsargos yra ilgam imobilizuotos (mobilesnės iš esmės yra tik armens sluoksnyje). Tačiau dėl nutrauktų kalkinimo darbų spartėjant dirvožemio rūgštėjimui, šių elementų mobilumas didėja, taip pat padidėja grėsmė susikaupti augaluose, patekti į mitybos grandinę ir užteršti gruntinius vandenis.
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Wilton, Katelynn Marie, and Daniel D. Billadeau. "Vasodilator Stimulated Phosphoprotein (VASP)-Mediated Actin Polymerization Drives Natural Killer Cell Granule Convergence." Journal of Immunology 200, no. 1_Supplement (May 1, 2018): 170.7. http://dx.doi.org/10.4049/jimmunol.200.supp.170.7.
Повний текст джерелаАнотація:
Abstract Natural killer (NK) cells eliminate transformed and malignant cells through a highly orchestrated series of actin and microtubule cytoskeletal rearrangements, culminating in the secretion of preformed lytic granules. Despite the importance of actin and microtubules, the roles of many molecular cytoskeletal regulators in this process have not yet been ascertained. In this study, we investigated the role of Vasodilator Stimulated Phosphoprotein (VASP), an actin regulatory protein, in NK cell-mediated cytotoxicity. Interestingly, we found that depletion of VASP inhibits NK cell cytotoxicity and that VASP co-localizes with F-actin at the NK cell – target cell cytotoxic synapse. Surprisingly, despite their co-localization, VASP depletion did not affect either F-actin accumulation at the cytotoxic synapse or conjugate formation. Instead, we found that a minority of VASP localized and biochemically co-purified with cytolytic granules. Although VASP knockdown did not affect microtubule organizing center (MTOC) polarization, it did dramatically impact lytic granule convergence to the MTOC. Significantly, VASP depletion decreased F-actin accumulation on cytolytic granules and depolymerization of F-actin with Latrunculin A impaired lytic granule convergence. Taken together, these results demonstrate a novel requirement for VASP-mediated actin polymerization in NK cell granule convergence and cytotoxicity and highlight a role for F-actin in lytic granule convergence.
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Khan, Mohammad Tanzimudin, and Tony Lynch. "The Genealogy of Contemporary Nature/Forest Conservation." Human Geography 6, no. 3 (November 2013): 105–20. http://dx.doi.org/10.1177/194277861300600309.
Повний текст джерелаАнотація:
We seek to understand the contemporary adaptive co-management framework of natural/forest resource conservation. To do this we trace the genealogy of adaptive co-management and its call for the “democratic participation” of “all stakeholders”. We show how this inserted commercial agents as stakeholders, thus providing contemporary neoliberal accumulation regimes with a problem-solving framework for natural/forest conservation shaped by, and amenable to, their characteristic managerial discourse of “flexibility”, “innovation”, “voluntary self-regulation”, “incentivization”, “partnership”, “network(ing)”, “social learning” and “local knowledge”.
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Ivanchenko, V. V., V. A. Baranov, N. V. Vyatkina, and N. M. Dorokhova. "Effective use of solar collectors in heat supply systems in the Siberian region." Interexpo GEO-Siberia 8, no. 2 (May 18, 2022): 133–37. http://dx.doi.org/10.33764/2618-981x-2022-8-2-133-137.
Повний текст джерелаАнотація:
The article discusses the possibility of more efficient use of solar collectors and use in heat supply systems in the Siberian region. The symbiosis of storage and accumulation of solar energy is considered. The development of Novosibirsk scientists on methods of accumulating solar energy was studied, air and water solar collectors were manufactured, tested. It is concluded that collectors can be used to maintain plus energy indoor temperatures, use to heat water; the use of solar collectors may reduce heating costs, which will not be taxed on CO; the use of solar collectors can also significantly reduce the use of natural resources and, as a result, reduce the environmental burden on the environment. Practical significance: the results of the study can be used both in real everyday situations and in physics lessons when studying the transformation of energy and solving practical problems.
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Malapi-Nelson, M., R. H. Wen, B. H. Ownley, and M. R. Hajimorad. "Co-infection of Soybean with Soybean mosaic virus and Alfalfa mosaic virus Results in Disease Synergism and Alteration in Accumulation Level of Both Viruses." Plant Disease 93, no. 12 (December 2009): 1259–64. http://dx.doi.org/10.1094/pdis-93-12-1259.
Повний текст джерелаАнотація:
Co-infection of potyviruses with taxonomically diverse plant viruses results in disease synergism and elevation in the level of accumulation of non-potyviruses involved. In the majority of cases, however, the accumulation level of potyviruses remains essentially unaltered. A few potyviruses, such as Soybean mosaic virus (SMV), naturally infect soybean (Glycine max). Soybean is also a natural host to a number of non-potyviruses including Alfalfa mosaic virus (AMV), which causes mild symptoms often associated with symptom remission. We have now studied the interactions between AMV and SMV on symptom severity and accumulation level of each of the two viruses in soybean. Co-infection of soybean with AMV and SMV was established following mechanical inoculation, irrespective of simultaneous or sequential introduction of the two viruses. In multiple experiments, co-infection of soybean resulted in severe symptoms in doubly infected plants in a strain-independent manner, with enhancement in the level of AMV indicating that the interaction of AMV with SMV is synergistic. Conversely, the level of SMV accumulation was reduced. This suggests that in co-infection with AMV, SMV interacts antagonistically. The observation that co-infection of AMV and SMV results in disease synergism suggests enhancement of potential that AMV may become a serious viral disease of soybean.
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Burden, A., A. Garbutt, and C. D. Evans. "Effect of restoration on saltmarsh carbon accumulation in Eastern England." Biology Letters 15, no. 1 (January 2019): 20180773. http://dx.doi.org/10.1098/rsbl.2018.0773.
Повний текст джерелаАнотація:
Wetland soils are globally important carbon stores, and natural wetlands provide a sink for atmospheric carbon dioxide (CO 2 ) through ongoing carbon accumulation. Recognition of coastal wetlands as a significant contributor to carbon storage (blue carbon) has generated interest into the climate change mitigation benefits of restoring or recreating saltmarsh habitat. However, the length of time a re-created marsh will take to become functionally equivalent to a natural (reference) system, or indeed, whether reference conditions are attainable, is largely unknown. Here, we describe a combined field chronosequence and modelling study of saltmarsh carbon accumulation and provide empirically based predictions of changes in the carbon sequestration rate over time following saltmarsh restoration. Carbon accumulation was initially rapid (average 1.04 t C ha −1 yr −1 during the first 20 years), slowing to a steady rate of around 0.65 t C ha −1 yr −1 thereafter. The resulting increase in C stock gave an estimated total C accumulation of 74 t C ha −1 in the century following restoration. This is approximately the same as our observations of natural marsh C content (69 t C ha −1 ), suggesting that it takes approximately 100 years for restored saltmarsh to obtain the same carbon stock as natural sites.
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Odom, A. L., and W. J. Rink. "Natural accumulation of Schottky-Frenkel defects: Implications for a quartz geochronometer." Geology 17, no. 1 (1989): 55. http://dx.doi.org/10.1130/0091-7613(1988)017<0055:naosfd>2.3.co;2.
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Duan, Hai Jing, Zhi Qi Tong, and Jian Hua Ma. "Accumulation Sequences of Heavy Metals in Poplar Tree-Rings in Kaifeng City, China." Advanced Materials Research 347-353 (October 2011): 2308–12. http://dx.doi.org/10.4028/www.scientific.net/amr.347-353.2308.
Повний текст джерелаАнотація:
Sixteen tree-rings of Polar (P. Euramericana) were collected in the different function districts of Kaifeng City, China. Concentrations of Cu and Zn in the xylem of tree-rings from 1990 to 2009 were measured using F-AAS, and that of Co using ICP-MS. The results show that concentrations of Cu and Zn in tree-rings in the control area do not vary significantly in the period from 1990 to 2009 and much lower than that in urban areas. The accumulation sequences of Zn in tree-rings in different urban districts appear increasing trends in the period, and that of Cu present waved rising trends. The sequences of Co in tree-rings both in urban and control area had no significant change in the period. Copper and Zinc are the typical anthropogenic metals, and Co is a natural source metal. We can understand the heavy metal pollution changes in urban area from their accumulation sequences in tree-rings.
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Ni, Xia, Ji Ma, Jiangong Li, Juanjuan Huang, Dongmao Jiao, and Zhibin Lu. "Structure and Microwave Characteristics of Co/TiO2 Nanocomposites Prepared by Ball Milling." Journal of Nanoscience and Nanotechnology 8, no. 9 (September 1, 2008): 4470–76. http://dx.doi.org/10.1166/jnn.2008.293.
Повний текст джерелаАнотація:
Co/TiO2 nanocomposites were fabricated via direct ball milling. The structure and microwave characteristics of the Co/TiO2 nanocomposites were investigated. The results show that the hcp and fcc Co phases coexist in the nanocomposites for a long milling duration. The accumulation of the stacking faults in Co and the increase of the Co/TiO2 interfaces were detected by nuclear magnetic resonance. The measured relative complex permittivity of the Co/TiO2 nanocomposite-paraffin wax mixture indicates that a high electrical resistivity and a dielectric loss exist in the Co/TiO2 nanocomposites. The dielectric loss mainly results from the polarisation of the metal/insulator interfaces. The imaginary part of the relative complex permeability of the mixture exhibits a broad resonance peak at 5.1 GHz which originates from the natural resonance in Co. The broadening of the resonance peak can be attributed to the fluctuating magnetocrystalline anisotropy at the stacking faults and interfaces regions. The calculated reflection loss curves show that the minimal reflection loss value of the Co/TiO2 nanocomposite-paraffin wax mixture can reach −32 dB at 4.0 GHz with a 3 mm sample thickness. The improved microwave absorption properties may result from the high electrical resistivity, dielectric loss and natural resonance.
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Potijun, Supakorn, Suparat Jaingam, Nuttha Sanevas, Srunya Vajrodaya, and Anchalee Sirikhachornkit. "Improving the co-production of triacylglycerol and isoprenoids in Chlamydomonas." Biofuel Research Journal 7, no. 4 (December 1, 2020): 1235–44. http://dx.doi.org/10.18331/brj2020.7.4.2.
Повний текст джерелаАнотація:
Biodiesel and natural products derived from microalgae require a smaller land area and have higher production rates compared to plants and animals and has recently attracted considerable interest. However, biodiesel production from microalgal triacylglycerol is still far from commercial realization due to its high production cost. One way to overcome this obstacle is to improve the triacylglycerol accumulation and couple its production with other high-value compounds. Of particular interest is the sterol biosynthetic pathway with squalene as an intermediate due to its close relationship with triacylglycerol and carotenoid biosynthetic pathways. Besides, both squalene and carotenoids are isoprenoid lipids that have health benefits. Perturbation of one pathway has been suggested to affect other pathways. Three terbinafine-sensitive mutants of the green microalga Chlamydomonas reinhardtii were isolated using terbinafine, a drug that inhibits squalene epoxidase, leading to squalene accumulation. One of the mutants, tfs2, accumulated twice the amount of wild-type triacylglycerol. As well as squalene accumulation, the presence of terbinafine further increased the triacylglycerol content. The level of prenyl lipid carotenoid and chlorophyll was also more significant than that of the wild type. Growth and photosynthesis were not compromised in this mutant. This is the first study that has demonstrated a mutant screening method to improve the co-production of TAG and isoprenoid lipids in a green microalgae.
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Mambelli-Lisboa, Nicole, Juliana Mozer Sciani, Alvaro Rossan Brandão Prieto da Silva, and Irina Kerkis. "Co-Localization of Crotamine with Internal Membranes and Accentuated Accumulation in Tumor Cells." Molecules 23, no. 4 (April 20, 2018): 968. http://dx.doi.org/10.3390/molecules23040968.
Повний текст джерелаАнотація:
Crotamine is a highly cationic; cysteine rich, cross-linked, low molecular mass cell penetrating peptide (CPP) from the venom of the South American rattlesnake. Potential application of crotamine in biomedicine may require its large-scale purification. To overcome difficulties related with the purification of natural crotamine (nCrot) we aimed in the present study to synthesize and characterize a crotamine analog (sCrot) as well investigate its CPP activity. Mass spectrometry analysis demonstrates that sCrot and nCrot have equal molecular mass and biological function—the capacity to induce spastic paralysis in the hind limbs in mice. sCrot CPP activity was evaluated in a wide range of tumor and non-tumor cell tests performed at different time points. We demonstrate that sCrot-Cy3 showed distinct co-localization patterns with intracellular membranes inside the tumor and non-tumor cells. Time-lapse microscopy and quantification of sCrot-Cy3 fluorescence signalss in living tumor versus non-tumor cells revealed a significant statistical difference in the fluorescence intensity observed in tumor cells. These data suggest a possible use of sCrot as a molecular probe for tumor cells, as well as, for the selective delivery of anticancer molecules into these tumors.
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Niu, Yajie, Wenjun Liang, Xi Wei, and Youzhi Han. "Forest Gaps Modulate the Composition and Co-Occurrence Network of Soil Bacterial Community in Larix principis-rupprechtii Mayr Plantation." Agronomy 13, no. 1 (December 22, 2022): 38. http://dx.doi.org/10.3390/agronomy13010038.
Повний текст джерелаАнотація:
Forest gaps create a favorable microenvironment for the growth of the soil microbial community. This study aimed to explore the effects of gap-related microenvironmental heterogeneity on soil bacterial communities in Larix principis-rupprechtii Mayr forest gaps. Therefore, the redundancy analysis (RDA) and structure equations modeling (SEM) of affecting elements were further used to test the significance of forest gaps’ effect on soil bacterial community composition and co-occurrence structure complexity. The formation of forest gaps increased canopy opening (CO) and significantly increased soil moisture content (SW), soil temperature (ST) and the accumulation of acid phosphatase (PHO) and sucrase (INV) in the soil, and the G250 (forest gap size: >250 m2) was most conductive to the accumulation of light and soil total nutrient. G50, G70, and G100 (forest gap size: 50–70 m2, 70–100 m2, 100–125 m2) were most favorable for the natural regeneration of the L. principis-rupprechtii Mayr plantation. The light properties under the forest gaps were the most significant factor that influenced the soil bacterial community composition, followed by the size of the forest gap, with standard path coefficients (Std. PCs) of 0.45 and −0.37, respectively. The canopy opening (CO), relative light intensity (RLA) and leaf area index (LAI) were considered to be the most important environmental factors affecting bacterial community composition (Std. PCs: 0.97, 0.99, and −0.93, respectively). The natural regeneration density under the forest gap was the most significant factor influencing the complexity of the soil bacterial community co-occurrence network, followed by soil nutrients (Std. PCs: 0.87 and −0.76, respectively).
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Martín, Susana, and Santiago F. Elena. "Application of game theory to the interaction between plant viruses during mixed infections." Journal of General Virology 90, no. 11 (November 1, 2009): 2815–20. http://dx.doi.org/10.1099/vir.0.012351-0.
Повний текст джерелаАнотація:
Natural mixed infections of plant viruses are frequent, often leading to unpredictable variations in symptoms, infectivity, accumulation and/or vector transmissibility. Cauliflower mosaic caulimovirus (CaMV) has often been found in mixed infections with turnip mosaic potyvirus (TuMV) in plants of the genus Brassica. This study addressed the effect of mixed infection on infectivity, pathogenicity and accumulation of CaMV and TuMV in Arabidopsis thaliana plants inoculated mechanically with cDNA infectious clones. In singly infected plants, TuMV accumulation was approximately 8-fold higher than that of CaMV. In co-infected plants, there was 77 % more TuMV accumulation compared with single infections, whilst the accumulation of CaMV was 56 % lower. This outcome describes a biological game in which TuMV always plays the winner strategy, leading to the competitive exclusion of CaMV. However, the infectivity of each virus was not affected by the presence of the other, and no symptom synergism was observed.
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Patton, John T., Theodore Smith, Leonard D. Shultz, and John L. Magnani. "Pan-Selectin Inhibitor GMI-1070 Blocks Cell Adhesion of Acute Myelogenous Leukemia Cell Lines." Blood 112, no. 11 (November 16, 2008): 4039. http://dx.doi.org/10.1182/blood.v112.11.4039.4039.
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Abstract Most patients with acute myelogenous leukemia (AML) initially respond to chemotherapy but later relapse and die from the disease (50–70%). One mechanism by which AML cells resist treatment with anti-proliferative drugs is by cell adhesion in protective microenvironments in areas such as the bone marrow. Here, we investigate the effects of GMI-1070 on the mechanism of adhesion of an AML cell line (MV-4-11) derived from biphenotypic myelomonocytic cells. GMI-1070 is a small molecule rationally designed pan-selectin antagonist with particularly strong activity for E-selectin (IC50 = 3.4 μM). Over 95% of these AML cells express ligands for E and P-selectins as determined by fluorescence-activated cell sorter analysis using E or P-selectin/hIg chimeras. Virtually all of these cells strongly express the specific E-selectin ligands CD65 and FH-6 using flow cytometry. The ability of these AML cells to roll and adhere to E or P-selectin expressed on monolayers of human endothelial cells (HUVECs) under the shear forces of normal blood flow was determined in vitro using flow chambers. The data was captured by videomicroscopy and processed using digital imaging. AML cells rolled and adhered to endothelium expressing E or P-selectin and both forms of adhesion are inhibited by GMI-1070. In contrast, much less rolling and adhesion was observed by multiple myeloma cell line U-266 only on endothelial cells expressing P-selectin although these specific interactions are also inhibited by GMI-1070. To analyze the adhesion, homing and infiltration of this AML cell line in vivo, recently developed NOD-scid IL2rgnull mice were used as hosts for in vivo experimentation. These mice lack adaptive immune function, are completely deficient in host natural killer cells and support long term growth of primary human leukemias (AML, CML, and ALL). Mice were injected i.v. with MV-4-11 AML cells (1 × 106) and blood samples were taken from the retro-orbital plexus at 1 and 2 weeks post injection. Blood counts were performed using an ADVIA Hematology Analyzer. At intervals post injection, the presence of AML cells in the bone marrow (BM), spleen, and peripheral blood was determined by flow cytometry of cells co-expressing human CD45 and human CD33. At 3 weeks, AML cells represented 26% of cells in the bone marrow and 2.3% of cells in the spleen. At 6 weeks, high percentages of AML cells were found in both tissues as well as in the blood (bone marrow, 83%; spleen, 69%; blood, 36%). Histological analyses showed accumulations of AML cells in the BM, spleen, lungs, liver, kidneys, and ovaries. At these later stages, hematopoietic cells in the BM cavity were largely replaced by sheets of leukemic cells. This model proved to be effective in studying the homing of an AML cell line to protective environments in the bone marrow and dissemination of disease to other organs and is being used to determine the effects on cell adhesion-mediated drug resistance (CAM-DR) by selectin-mediated inhibition of adhesion using small molecule antagonist, GMI-1070. GMI-1070 is currently in Phase I clinical trials.
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Bobryshev, Yuri V., and Reginald S. A. Lord. "Co-accumulation of Dendritic Cells and Natural Killer T Cells within Rupture-prone Regions in Human Atherosclerotic Plaques." Journal of Histochemistry & Cytochemistry 53, no. 6 (June 2005): 781–85. http://dx.doi.org/10.1369/jhc.4b6570.2005.
Повний текст джерелаАнотація:
We previously reported that CD1d, a molecule responsible for the presentation of lipid antigens, is expressed in atherosclerotic lesions and that its expression is restricted to dendritic cells. Recent studies demonstrating that CD1d-restricted natural killer T (NKT) cells are involved in atherogenesis prompted the present study investigating whether NKT cells are present in human atherosclerotic lesions and, if so, whether there is an association between NKT cells and dendritic cells. We found that NKT cells do accumulate in rupture-prone shoulders of atherosclerotic plaques and observed direct contacts of dendritic cells with NKT cells in rupture-prone regions of plaque.
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Alekseenko, Vladimir, Natalya Shvydkaya, Jaum Bech, Alexander Puzanov, and Aleksey Nastavkin. "Trace element accumulation by soils and plants in the North Caucasian geochemical province." Journal of Mining Institute 247 (March 16, 2021): 1–13. http://dx.doi.org/10.31897/pmi.2021.1.15.
Повний текст джерелаАнотація:
Long-term studies of the North Caucasian geochemical province allowed to establish regional abundances and calculate accumulation (dispersion) factors for chemical elements in rocks, soils, and plants. Certain natural regional patterns characterize the province. Associations of elements in high and low concentrations are often determined by the predominant composition of rocks: carbonate-terrigenous, terrigenous, and igneous. The study of the average contents of several chemical elements in the soils of the province showed that the association of accumulated elements includes metals with different migration characteristics. Thus, despite the rather close values of the ionic radii, Pb, Zn, Cu, and Li (judging by the ionic potential) are characterized by the formation of cations, while Mn, Mo, and Zr form complex ions. Such elements as Zn, Cu, and Pb are mainly accumulated on hydrosulfuric barriers, while Mo, Co, and Mn are stopped by oxygenous barriers. For Cu, Zn, Mo, and Co, biogenic accumulation plays a significant role, while for Pb and Ni it is practically absent. The absolute dispersion of the elements did not reach environmentally hazardous values, although it indicates a fairly intensive migration. In woody plants, Ba, Nb, Sc, Sr, and Zn are accumulated most intensively.
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Chen, Hongling, Dandan Wu, Qiao Wang, Lihu Fang, Yanan Wang, Changlin Zhan, Jiaquan Zhang, et al. "The Predominant Sources of Heavy Metals in Different Types of Fugitive Dust Determined by Principal Component Analysis (PCA) and Positive Matrix Factorization (PMF) Modeling in Southeast Hubei: A Typical Mining and Metallurgy Area in Central China." International Journal of Environmental Research and Public Health 19, no. 20 (October 14, 2022): 13227. http://dx.doi.org/10.3390/ijerph192013227.
Повний текст джерелаАнотація:
To develop accurate air pollution control policies, it is necessary to determine the sources of different types of fugitive dust in mining and metallurgy areas. A method integrating principal component analysis and a positive matrix factorization model was used to identify the potential sources of heavy metals (HMs) in five different types of fugitive dust. The results showed accumulation of Mn, Fe, and Cu can be caused by natural geological processes, which contributed 38.55% of HMs. The Ni and Co can be released from multiple transport pathways and accumulated through local deposition, which contributed 29.27%. Mining-related activities contributed 20.11% of the HMs and showed a relatively high accumulation of As, Sn, Zn, and Cr, while traffic-related emissions contributed the rest of the HMs and were responsible for the enrichment in Pb and Cd. The co-applied source-identification models improved the precision of the identification of sources, which revealed that the local geological background and mining-related activities were mainly responsible for the accumulation of HMs in the area. The findings can help the government develop targeted control strategies for HM dispersion efficiency.
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Shchegolkov, A. V., A. V. Shchegolkov, V. S. Yagubov, A. S. Zorin, and A. V. Kobelev. "Heat storage materials based on nanomodified paraffin, controlled by a magnetic field." Proceedings of the Voronezh State University of Engineering Technologies 80, no. 4 (March 21, 2019): 344–48. http://dx.doi.org/10.20914/2310-1202-2018-4-344-348.
Повний текст джерелаАнотація:
The article presents studies of nano-modified heat-accumulating materials controlled by a magnetic field. Paraffin is used as a material with the effect of energy accumulation in the phase transition. Carbon nanotubes are used to modify paraffin. For the synthesis of carbon nanotubes used catalyst Co-Mo/Al2O3-MgO. The synthesis process is based on the CVD method. The method of obtaining nanomodified paraffin with ferromagnetic properties is described. To impart paraffin ferromagnetic properties, a ferromagnetic powder previously ground with carbon nanotubes was introduced into it. Mechanical activation was used for the ferromagnetic powder, which provided particles with an average size of 5 ?m. The analysis of charge control regimes of a paraffin-based heat-accumulating material was carried out using a non-contact method for measuring the temperature field. For this purpose, the FLUKE Ti9 thermal imager with a 160 x 120 radiation detector and a matrix in the focal plane and a measurement range from -20 to +250? was used. The morphology and structure of the synthesized carbon nanotubes were studied by scanning electron microscopy (a Hitachi H-800 transmission electron microscope). The behavior of the modified paraffin in the conditions of mineral motor oil under the influence of electromagnetic fields was studied. The design of a heat accumulator for working with a magnetically controlled heat-accumulating material is proposed. It is established that the heat transfer in the system is provided by two simultaneously occurring processes of natural and thermomagnetic convection. In turn, convection can be realized by changing the magnetic susceptibility with a change in temperature and with a geometric change in the position of a magnet or a group of magnets.
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Villamil-Garzón, Angela, Wilmer J. Cuellar, and Mónica Guzmán-Barney. "Natural co-infection of Solanum tuberosum crops by the Potato yellow vein virus and potyvirus in Colombia." Agronomía Colombiana 32, no. 2 (May 1, 2014): 213–23. http://dx.doi.org/10.15446/agron.colomb.v32n2.43968.
Повний текст джерелаАнотація:
The Potato yellow vein virus (PYVV), a Crinivirus with an RNA tripartite genome, is the causal agent of the potato yellow vein disease, reported in Colombian since 1950, with yield reductions of up to 50%. Co-infection of two or more viruses is common in nature and can be associated with differences in virus accumulation and symptom expression. No evidence of mixed infection between PYVV and other viruses has been reported. In this study, eight plants showing yellowing PYVV symptoms: four Solanum tuberosum Group Phureja (P) and four Group Andigena (A), were collected in Cundinamarca, Colombia to detect mixed infection in the isolates using next generation sequencing (NGS). The Potato virus Y (PVY) complete genome (similar to N strain) and the Potato virus V (PVV) partial genomes were detected using NGS and re-confirmed by RT-PCR. Preliminary field screening in a large sample showed that PYVV and PVY co-infect potato plants with a prevalence of 21% within the P group and 23% within the A group. This is the first report of co-infection of PYVV and potyvirus in Colombia and with the use of NGS. Considering that potyviruses enhance symptom severity and/or yield reductions in mixed infections, our results may be relevant for disease diagnosis, breeding programs and tuber certification.
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Ong, SuFey, Davinna Ligons, Jobert Barin, Lei Wu, Monica Talor, Nicola Diny, Jillian Fontes, Elizabeth Gebremariam, Noel Rose, and Daniela Cihakova. "Natural killer cells protect against cardiac inflammation and fibrosis by directly limiting eosinophilic accumulation (BA7P.144)." Journal of Immunology 194, no. 1_Supplement (May 1, 2015): 115.4. http://dx.doi.org/10.4049/jimmunol.194.supp.115.4.
Повний текст джерелаАнотація:
Abstract Myocarditis is the inflammation of the cardiac muscle and is among the leading causes of sudden cardiac failure in young adults. We demonstrate here that natural killer (NK) cells, a subset of the Type I innate lymphoid cell (ILC) group, suppress experimental autoimmune myocarditis (EAM). EAM was initiated in BALB/c mice by immunization with myocarditogenic peptide emulsified in complete Freund's adjuvant. During disease, activated cardiac NK cells accumulated in the heart, secreted interferonγ, perforin, and granzyme-B, and expressed activation markers CD69, TRAIL, and CD27. The depletion of NK cells during EAM with anti-asialo GM1 antibody resulted in a 10-fold increase from 0.12 - 12.0% in the percentage of eosinophils found in the cardiac tissue at the peak of disease. This was accompanied by significantly increased myocarditis severity and elevated fibrosis. Eosinophils were required for the change in disease severity in the absence of NK cells, as treatment with anti-asialo GM1 did not increase myocarditis severity in eosinophil-deficient ΔdoubleGATA1 mice. We show that NK cells limited eosinophilic infiltration during EAM indirectly through altering eosinophil-related chemokine production by resident cardiac fibroblasts both in vitro and in vivo. Additionally, the co-culture of NK cells and eosinophils directly induced eosinophil apoptosis in vitro. Altogether, we define a new pathway of eosinophilic regulation through interactions with NK cells.
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Wang, Shuhao, Junfeng Shen, Baisong Du, Kexin Xu, Zhengshuai Zhang, and Chengyu Liu. "The Relationship between Natural Pyrite and Impurity Element Semiconductor Properties: A Case Study of Vein Pyrite from the Zaozigou Gold Deposit in China." Minerals 11, no. 6 (June 1, 2021): 596. http://dx.doi.org/10.3390/min11060596.
Повний текст джерелаАнотація:
Pyrite is a common sulfide mineral in gold deposits, and its unique thermoelectricity has received extensive attention in the field of gold exploration. However, there is still a lack of detailed research and direct evidence about how impurity elements affect mineral semiconductor properties. In this paper, combined with first-principles calculations, laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) mapping technology and in situ Seebeck coefficient scanning probe technology were used to study the law of changing semiconductor properties in pyrite containing impurity elements such as As, Co, Ni, and Cu. The results showed that pyrite containing arsenic is a P-type semiconductor, and pyrites containing Ni, Co, Cu, and other elements are N-type semiconductors. When P-type pyrites containing As were supplemented with Ni, Cu, and other elements, the semiconductor type changed to N-type. However, Co addition did not change the semiconductor type of arsenic-rich pyrite. Pyrite formed under different temperature conditions tended to be enriched with different combinations of impurity elements, leading to the relative accumulation of P-type or N-type pyrites.
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MacLeod, Matthew, Hans Peter H. Arp, Mine B. Tekman, and Annika Jahnke. "The global threat from plastic pollution." Science 373, no. 6550 (July 1, 2021): 61–65. http://dx.doi.org/10.1126/science.abg5433.
Повний текст джерелаАнотація:
Plastic pollution accumulating in an area of the environment is considered “poorly reversible” if natural mineralization processes occurring there are slow and engineered remediation solutions are improbable. Should negative outcomes in these areas arise as a consequence of plastic pollution, they will be practically irreversible. Potential impacts from poorly reversible plastic pollution include changes to carbon and nutrient cycles; habitat changes within soils, sediments, and aquatic ecosystems; co-occurring biological impacts on endangered or keystone species; ecotoxicity; and related societal impacts. The rational response to the global threat posed by accumulating and poorly reversible plastic pollution is to rapidly reduce plastic emissions through reductions in consumption of virgin plastic materials, along with internationally coordinated strategies for waste management.
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Shopska, Maya, Zara Cherkezova-Zheleva, Daniela Paneva, Mihail Iliev, Georgi Kadinov, Ivan Mitov, and Veneta Groudeva. "Biogenic iron compounds: XRD, Mossbauer and FTIR study." Open Chemistry 11, no. 2 (February 1, 2013): 215–27. http://dx.doi.org/10.2478/s11532-012-0148-5.
Повний текст джерелаАнотація:
AbstractMaterials based on biogenic iron oxides, which are a product of the metabolic activities of the neutrophilic iron-oxidizing bacteria (NIOB) from Sphaerotilus-Leptothrix group, were investigated. Natural microbial probes were collected from freshwater flow from Vitosha Mountain (Bulgaria) and cultivated under laboratory conditions in respect to select suitable cultures and conditions (nutrition media) for biomaterial accumulation of biogenic oxides. Samples were studied by physicochemical methods: X-ray diffraction, Mossbauer spectroscopy and IR spectroscopy. Their phase composition and physicochemical properties were obtained. Presence of both amorphous and crystal phase (ultra- and highly dispersed particles) was proved. Iron-containing compound in the natural biomass consists of α-FeOOH. The cultivated materials have more complex composition with iron-containing ingredients as α-FeOOH, Γ-FeOOH, Γ-Fe2O3 and Fe3O4. The sample of natural biomass was tested in reaction of CO oxidation and it showed potential to be used as catalyst support.
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Lin, Shian-Ren, and Ching-Feng Weng. "PG-Priming Enhances Doxorubicin Influx to Trigger Necrotic and Autophagic Cell Death in Oral Squamous Cell Carcinoma." Journal of Clinical Medicine 7, no. 10 (October 21, 2018): 375. http://dx.doi.org/10.3390/jcm7100375.
Повний текст джерелаАнотація:
Synergistic effects between natural compounds and chemotherapy drugs are believed to have fewer side effects with equivalent efficacy. However, the synergistic potential of prodigiosin (PG) with doxorubicin (Dox) chemotherapy is still unknown. This study explores the synergistic mechanism of PG and Dox against oral squamous cell carcinoma (OSCC) cells. Three OSCC cell lines were treated with different PG/Dox combinatory schemes for cytotoxicity tests and were further investigated for cell death characteristics by cell cycle flow cytometry and autophagy/apoptosis marker labelling. When OSCC cells were pretreated with PG, the cytotoxicity of the subsequent Dox-treatment was 30% higher than Dox alone. The cytotoxic efficacy of PG-pretreated was found better than those of PG plus Dox co-treatment and Dox-pretreatment. Increase of Sub-G1 phase and caspase-3/LC-3 levels without poly (ADP-ribose) polymeras (PARP) elevation indicated both autophagy and necrosis occurred in OSCC cells. Dox flux after PG-priming was further evaluated by rhodamine-123 accumulation and Dox transporters analysis to elucidate the PG-priming effect. PG-priming autophagy enhanced Dox accumulation according to the increase of rhodamine-123 accumulation without the alterations of Dox transporters. Additionally, the cause of PG-triggered autophagy was determined by co-treatment with endoplasmic reticulum (ER) stress or AMP-activated protein kinase (AMPK) inhibitor. PG-induced autophagy was not related to nutrient deprivation and ER stress was proved by co-treatment with specific inhibitor. Taken together, PG-priming autophagy could sensitize OSCC cells by promoting Dox influx without regulation of Dox transporter. The PG-priming might be a promising adjuvant approach for the chemotherapy of OSCC.
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Carrillo, Eduardo, Franck A. Audemard M., Christian Beck, Michel Cousin, François Jouanne, Victor Cano, Raymi Castilla, Luis Melo, and Thierry Villemin. "A Late Pleistocene-Holocene natural seismograph along the Boconó Fault (Mérida Andes, Venezuela): the moraine-dammed Los Zerpa paleo-lake." Bulletin de la Société Géologique de France 177, no. 1 (January 1, 2006): 3–17. http://dx.doi.org/10.2113/177.1.3.
Повний текст джерелаАнотація:
Abstract The Boconó Fault system is a major active tectonic feature accommodating an important part of the dextral relative motion between the Caribbean Plate and northern South-America. The main trace follows an axial valley running SW-NE within the Mérida Andes (northwestern Venezuela), and crosscuts a series of moraines related to late Pleistocene glaciers developments and retreats, at an altitude between 2600 and 5000 m. Several lakes were generated after the last retreat (between the Late Glacial Maximum –LGM– and the Younger Dryas re-advance), dammed by lateral and frontal moraines. Among them, the Los Zerpa moraine system yielded rich outcrops ranging from an upstream very coarse torrential to deltaic fill, to a downstream clayey-silty horizontal laminated lacustrine accumulation; a fore-set-type heterogeneous “prograding” body links the two sets. The whole system, as well as the surrounding moraines, underwent successive major earthquakes during the Late Glacial/lower Holocene period as evidenced by co-seismic scarps in the moraines, migrations of the outlet, and associated sagponds. Besides active faulting affecting both the moraines and the sedimentary fill, the latter –main purpose of our detail study– exhibits various evidence of strong disturbances which we relate to seismic shaking, such as: i) successive unconformities with co-seismic slips along fractures in the coarse proximal sediments; ii) successive dip changes, discontinuities, and slumps in the foreset-like set; iii) slumps with basal liquefaction, syn-sedimentary fractures, and instantaneous re-sedimentation in the fine-grained laminated accumulation. Lateral (temporal) correlations are established between the successive disturbances detected in the three situations; in turn, these sedimentary events are correlated with seismic activity of the Boconó Fault main trace. Thus, the whole paleo-lake may be considered as a natural seismograph which worked during several thousands years, after the end of the LGM and during early Holocene.
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Graham, Sean A., Christopher B. Craft, Paul V. McCormick, and Allison Aldous. "Forms and accumulation of soil P in natural and recently restored peatlands—Upper Klamath Lake, Oregon, USA." Wetlands 25, no. 3 (September 2005): 594–606. http://dx.doi.org/10.1672/0277-5212(2005)025[0594:faaosp]2.0.co;2.
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Park, Eunkuk, Eunguk Lim, Subin Yeo, Yoonjoong Yong, Junga Yang, and Seon-Yong Jeong. "Anti-Menopausal Effects of Cornus officinalis and Ribes fasciculatum Extract In Vitro and In Vivo." Nutrients 12, no. 2 (January 30, 2020): 369. http://dx.doi.org/10.3390/nu12020369.
Повний текст джерелаАнотація:
Natural herbal medicines have been developed for the treatment and prevention of women’s menopausal symptoms. In this study, we investigated the anti-menopausal effects of Cornus officinalis (CO) and Ribes fasciculatum (RF) extracts in 3T3-L1 preadipocytes, MC3T3-E1 preosteoblasts, and COV434 granulosa cells in vitro and ovariectomized (OVX) ddY mice in vivo. Combination treatment of CO and RF extract at 7:3 ratio inhibited lipid accumulation via Plin1 and Adipoq downregulation in a cocktail of dexamethasone, 3-isobutyl-1-methylxanthine, and insulin (DMI)-induced differentiated 3T3-L1 cells. In addition, CO + RF treatment significantly enhanced osteoblastic differentiation, with mineralized nodule formation occurring through the upregulation of osteoblast-inducing markers in osteoblastic MC3T3-E1 cells. Increased production of estradiol and mRNA expression of ERα (ESR1) were observed in androstenedione-induced COV434 granulosa cells treated with the CO + RF extract. In CO + RF-treated mice, fatty hepatocyte deposition and abdominal visceral fat tissues reduced with OVX-induced uterine atrophy. Furthermore, bone mineral density and bone mineral content were significantly enhanced by CO + RF in mouse models of ovariectomy-induced femoral bone loss. Taken together, our findings suggested that CO + RF promoted estrogenic activity and had anti-obesity and anti-osteoporotic effects in vitro and in vivo. Thus, a combination of CO and RF extracts may be a good therapeutic strategy for managing women’s menopausal syndromes.
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Zinicovscaia, Inga, Constantin Hramco, Omari Chaligava, Nikita Yushin, Dmitrii Grozdov, Konstantin Vergel, and Gheorghe Duca. "Accumulation of Potentially Toxic Elements in Mosses Collected in the Republic of Moldova." Plants 10, no. 3 (March 2, 2021): 471. http://dx.doi.org/10.3390/plants10030471.
Повний текст джерелаАнотація:
For the second time, the moss biomonitoring technique was applied to evaluate the deposition of potentially toxic elements in the Republic of Moldova. The study was performed in the framework of the International Cooperative Program on Effects of Air Pollution on Natural Vegetation and Crops. Moss Hypnum cupressiforme Hedw. samples were collected in May 2020 from 41 sampling sites distributed over the entire territory of the country. The mass fractions of 35 elements (Na, Mg, Al, Cl, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Br, Se, Rb, Sr, Sb, Cs, Ba, Cd, La, Ce, Sm, Eu, Tb, Hf, Ta, Th, Pb, and U) were determined using neutron activation analysis and atomic absorption spectrometry. Comparing with 2015/2016 moss survey data, significant differences in the mass fractions of Cr, As, Se, Br, Sr, Sb, Cd, Pb, and Cu were found. Main air pollution sources (natural processes, transport, industry, agriculture, mining) were identified and characterized using factor and correlation analyses. GIS maps were built to point out the zones with the highest element mass fractions and to relate this to the known sources of contamination. Contamination factor, geo-accumulation index, pollution load index, and potential ecological risk index were calculated to assess the air pollution levels in the country. According to the calculated values, Moldova can be characterized as unpolluted to moderately polluted, with low potential ecological risk related to the degree of atmospheric deposition of potentially toxic elements. The cities of Chisinau and Balti were determined to experience particular environmental stress and are considered moderately polluted.
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Li, Tao, Päivi Tiiva, Åsmund Rinnan, Riitta Julkunen-Tiitto, Anders Michelsen, and Riikka Rinnan. "Long-term effects of elevated CO2, nighttime warming and drought on plant secondary metabolites in a temperate heath ecosystem." Annals of Botany 125, no. 7 (March 11, 2020): 1065–75. http://dx.doi.org/10.1093/aob/mcaa037.
Повний текст джерелаАнотація:
Abstract Background and Aims Plant secondary metabolites play critical roles in plant stress tolerance and adaptation, and are known to be influenced by the environment and climate changes, yet the impacts and interactions of multiple climate change components are poorly understood, particularly under natural conditions. Methods Accumulation of phenolics and emissions of volatile organic compounds (VOCs) were assessed on heather, Calluna vulgaris, an abundant evergreen dwarf shrub in European heathlands, after 6 years of exposure to elevated CO2, summer drought and nighttime warming. Key Results Drought alone had the strongest effects on phenolic concentrations and compositions, with moderate effects of elevated CO2 and temperature. Elevated CO2 exerted the greatest impact on VOC emissions, mainly by increasing monoterpene emissions. The response magnitudes varied among plant tissue types and chemical constituents, and across time. With respect to interactive effects of the studied climate change components, the interaction between drought and elevated CO2 was most apparent. Drought mainly reduced phenolic accumulation and VOC emissions, while elevated CO2 mitigated such effects. Conclusions In natural ecosystems, co-occurring climate factors can exert complex impacts on plant secondary metabolite profiles, which may in turn alter ecosystem processes.
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Dinić, Jelena, Ana Podolski-Renić, Marko Jeremić, and Milica Pešić. "Potential of Natural-Based Anticancer Compounds for P-Glycoprotein Inhibition." Current Pharmaceutical Design 24, no. 36 (February 15, 2019): 4334–54. http://dx.doi.org/10.2174/1381612825666190112164211.
Повний текст джерелаАнотація:
Medicinal value of natural products comes from symbiotic and competitive evolution in Earth’s complex biosphere. Billions of years of co-evolutionary interactions among millions of species have produced a large repertoire of defense molecules effective in fighting bacteria, viral, and fungal pathogens. Each species contains millions of different and useful molecules and new research technologies enabled the screening of molecules and complex mixtures from diverse biological sources. Traditional use of plants and other species led to the discovery of many bioactive compounds with various properties. In the last four decades, a large number of them were evaluated for their potential to treat cancer. Penetration of drugs into the cancer cell is necessary for their lethal pharmacological effect through interaction with intracellular target molecules. Increased activity of membrane efflux pumps reduces the intracellular drug accumulation, thereby preventing drug-target interactions. The discovery of the efflux transporter P-glycoprotein (P-gp) in multidrug resistant (MDR) cancer cells prompted the efforts in overcoming drug resistance by P-gp inhibition. The search for nontoxic anticancer agents from natural sources able to overcome MDR has been imperative in the field of drug design and discovery. Herein, we review various natural compounds from diverse sources emphasizing their potential to inhibit P-gp activity and/or expression.
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Jia, Xin, and Bo Yi. "Spatial Concentration Variation of Contaminants in a Residential Kitchen and the Effect of Makeup Air System." Advanced Materials Research 610-613 (December 2012): 1996–99. http://dx.doi.org/10.4028/www.scientific.net/amr.610-613.1996.
Повний текст джерелаАнотація:
In this paper, the experimental data of CO, CO2 and total volatile organic compound (TVOC) concentration in a residential kitchen are presented. Based on them, a simulation software with friendly and simply operating interfaceis is developed on the platform of VC++. The distribution law of the contaminants is studied via the simulation results, and it is obvious that location of accumulation of the contaminants are highly relevant to the location of stove and closer to the walls. An addition natural air makeup system is proposed to improve indoor airenvironment in kitchens, the effection of the air makeup system is analyzed with exergy theory.
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Shigabaeva, Gulnara N., Andrey V. Soromotin, Еvgeny V. Galunin, Аnna V. Ruseikina, Anna А. Kurbash, Andrey E. Petrov, and Alena D. Bashmachnikova. "Geo-ecological characteristics of the small lakes bottom sediments in the North of Western Siberia." Image Journal of Advanced Materials and Technologies 6, no. 4 (2021): 299–307. http://dx.doi.org/10.17277/jamt.2021.04.pp.299-307.
Повний текст джерелаАнотація:
The article analyzes and provides data on the processes of accumulation of heavy metals by bottom sediments from the point of view of environmental assessment. The purpose of this paper is to identify the degree of anthropogenic influence on the lakes of the Tazovskiy and Surgut districts, and assess the ecological state of water bodies and adjacent territories. The main processes occurring in natural reservoirs, which lead to the transfer of toxicants into the environment, are considered. The data of quantitative chemical analysis of bottom sediments of two groups of natural reservoirs with an assessment of their ecological state according to the results of statistical processing of the measured values were obtained. Excess concentrations of metals were recorded: for mobile forms – 2200 times for Fe, 1050 times for Mn, 35 times for Cr, 20 times for Co, up to 15 times for Ni, 5 times for Cu, 3 times for Pb, for acid-soluble forms – 45 000 times for Fe, 550 times for Pb, up to 75 times for Ni, 525 times for Mn, 105 times for Cr, 50 times for Cu, 16 times for Co. The geochemical interpretation of the results of the factor analysis is presented.
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Huang, Xuexia, Dinggui Luo, Dongye Zhao, Ning Li, Tangfu Xiao, Jingyong Liu, Lezhang Wei, Yu Liu, Lirong Liu, and Guowei Liu. "Distribution, Source and Risk Assessment of Heavy Metal(oid)s in Water, Sediments, and Corbicula Fluminea of Xijiang River, China." International Journal of Environmental Research and Public Health 16, no. 10 (May 23, 2019): 1823. http://dx.doi.org/10.3390/ijerph16101823.
Повний текст джерелаАнотація:
A total of 43 water and sediment samples, and 34 Corbicula fluminea samples were collected in Xijiang River in southern China to determine the spatial distribution and sources of 12 metals/metalloids (V, Co, Cr, Ni, Cu, Mn, Zn, Cd, Pb, As, Sb, and Tl) and to assess the pollution levels and ecological risks of the pollutants. The results showed that the levels of the metals/metalloids (except for Tl) in the river water from almost all of the sampling sites met the Chinese national surface water quality standards. However, the concentrations of the metals/metalloids in the sediments exceeded the background values by a factor of 1.03–56.56 except for V, Co, and Mn, and the contents of Zn, Cd, and Pb in the Corbicula fluminea soft tissue exceeded the limits of the Chinese Category I food Quality Standards. The spatial distribution analysis showed that the concentrations of the contaminants in the lower reaches of Xijiang River were higher than in the upper reaches. The bioaccumulation factor (BAF), biota-sediment accumulation factor (BSF), geo-accumulation index (Igeo), and the potential ecological risk index (RI) were obtained to assess the pollution levels and ecological risks. The results indicated that Cu, Cd, and Zn were the most prone to bio-accumulation in the Corbicula fluminea soft tissue, and the lower reaches showed a much higher pollution level and risk than the upper reaches. The metals/metalloids in the sediments posed serious threat on the aquatic ecosystem, of which Cd, As, and Sb are the most risky contaminants. The results of principal component analysis (PCA) indicated Cr, Ni, Cu, Mn, Cd, Pb, and As in the sediments came from relevant industrial activities, and V and Co originated from natural sources, and Sb from mining activities, Zn and Tl came from industrial activities and mining activities.
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Gololobova, Anna, Yana Legostaeva, Vladimir Popov, Victor Makarov, and Olesya Shadrinova. "Geochemical Characteristics of Soils to the Impact of Diamond Mining in Siberia (Russia)." Minerals 12, no. 12 (November 27, 2022): 1518. http://dx.doi.org/10.3390/min12121518.
Повний текст джерелаАнотація:
This article presents the results of long-term research and monitoring of the soil cover exposed to the impact of the mining and processing plant developing diamond deposits in the northeast of Siberia. The soil collection includes 436 samples of different types of Cryosols. Soil pH; soil organic carbon (SOC); granulometric composition; and mobile forms of Pb, Ni, Mn, Cd, Co, Cr, Zn, Cu, and As were identified in the samples. Multivariate statistics of the correlation matrix, clustering analysis (CA), and principal component analysis (PCA) were used to determine the sources of heavy metals. The intensity of the accumulation of chemical elements in the soil was assessed using calculated concentration coefficients (Kc) and the index of total contamination of the soil cover (Zc). In the study area, Cryosols are characterized by biogenic accumulation of Ni, Mn, and Cd in the upper soil layer and Cr, Ni, Co, Mn, and Cu in the suprapermafrost horizon. Correlation matrix, CA, and PCA revealed three distinct sources that could be considered for the investigated potentially toxic elements (PTEs): anthropogenic, lithogenic, and the source which comes from a mixed contribution of anthropogenic and lithogenic factors. The most anthropogenic contribution in the heavy metals in the study area appears in Zn, Cd, As, and Pb. The assessment interpreted that origin of Mn in the area is most likely to be a natural source. The content of Co, Cr, and Ni are controlled by both lithogenic control and anthropogenic sources. Active accumulation of mobile forms of Mn, Zn, and Ni with anomalously high concentration coefficients can be traced in the soils in the impact zone of mining operations. Anthropogenic soil contamination is spread over an area of 260 km2.
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Vinichuk, Mykhailo. "Selected Metals in Various Fractions of Soil and Fungi in a Swedish Forest." ISRN Ecology 2012 (July 5, 2012): 1–7. http://dx.doi.org/10.5402/2012/521582.
Повний текст джерелаАнотація:
The patterns of uptake and distribution of Co, Ni, Cu, Zn, Cd, and Pb in the soil-mycelium-sporocarps compartments in various transfer steps are presented. I attempted to find out whether there is a difference between the uptake of metals from soil to fungi (mycelium/soil ratio) and transport within fungal thalli (sporocarps/mycelium ratio). The concentration of Cu, Zn, and Cd increased in the order bulk soil < soil-root interface (or rhizosphere) < fungal mycelium < fungal sporocarps. The concentration of Co, Ni, and Pb decreased in the order bulk soil (or rhizosphere) < fungal mycelium < soil-root interface < fungal sporocarps. The uptake of Cu, Zn, and Cd during the entire transfer process in natural conditions between soil and sporocarps occurred against a concentration gradient. Mycorrhizal fungi (mycelium and sporocarps) only absorbed Co, Ni, and Pb but did not accumulate these elements in their thalli. Metal accumulation within fungal mycelium biomass in the top forest soil layer (0–5 cm) may account for about 5% of the total amount of Co, 4% Ni, 7% Cu, 8% Zn, 24% Cd, and 3% Pb.
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Chang, Y. C., S. C. Huang, and K. F. Chen. "Evaluation of the effects of nanoscale zero-valent iron (nZVI) dispersants on intrinsic biodegradation of trichloroethylene (TCE)." Water Science and Technology 69, no. 11 (March 31, 2014): 2357–63. http://dx.doi.org/10.2166/wst.2014.169.
Повний текст джерелаАнотація:
In this study, the biodegradability of nanoscale zero-valent iron (nZVI) dispersants and their effects on the intrinsic biodegradation of trichloroethylene (TCE) were evaluated. Results of a microcosm study show that the biodegradability of three dispersants followed the sequence of: polyvinyl alcohol-co-vinyl acetate-co-itaconic acid (PV3A) > polyoxyethylene (20) sorbitan monolaurate (Tween 20) > polyacrylic acid (PAA) under aerobic conditions, and PV3A > Tween 20 > PAA under anaerobic conditions. Natural biodegradation of TCE was observed under both aerobic and anaerobic conditions. No significant effects were observed on the intrinsic biodegradation of TCE under aerobic conditions with the presence of the dispersants. The addition of PAA seemed to have a slightly adverse impact on anaerobic TCE biodegradation. Higher accumulation of the byproducts of anaerobic TCE biodegradation was detected with the addition of PV3A and Tween 20. The diversity of the microbial community was enhanced under aerobic conditions with the presence of more biodegradable PV3A and Tween 20. The results of this study indicate that it is necessary to select an appropriate dispersant for nZVI to prevent a residual of the dispersant in the subsurface. Additionally, the effects of the dispersant on TCE biodegradation and the accumulation of TCE biodegrading byproducts should also be considered.
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BIDUSSI, Massimo, Knut Asbjørn SOLHAUG, and Yngvar GAUSLAA. "Increased snow accumulation reduces survival and growth in dominant mat-forming arctic-alpine lichens." Lichenologist 48, no. 3 (May 2016): 237–47. http://dx.doi.org/10.1017/s0024282916000086.
Повний текст джерелаАнотація:
AbstractRelative growth rates (RGR) and carbon-based secondary compounds (CBSCs) were quantified in four dominant terricolous arctic-alpine mat-forming lichens with different preferences for snow cover. The aim was to evaluate the effects of snow depth, and thus snow cover duration, on lichen growth and performance. The species,Alectoria ochroleuca,Flavocetraria nivalis,Cladonia mitisandCetrariella delisei, are associated with increasing snow depth, respectively. They were transplanted for one year at five snow depths (0, 60, 120, 160 and 200 cm measured in early May) along each of four natural ridge to snow bed gradient transects in oceanic-alpine sites (western Norway). Snow slightly thicker than in source habitats caused negative RGR in the ridge top-dependentA. ochroleucaand the co-occurringF. nivaliswith somewhat higher snow tolerance. OnlyC. mitiswith the broadest ecological niche had positive RGR along most of the gradients (0–160 cm), even outside its natural range. The most snow-tolerant species,C. delisei, tolerant also to temporal inundation in water, had the lowest RGR. Nevertheless, it performed as well in places with little or no snow as in places where it grows naturally. Snow depth significantly affected total concentrations of CBSCs mainly inA. ochroleuca, which experienced substantial mass loss under snow. There was a highly significant increase in usnic acid concentration with increasing mass loss inA. ochroleuca, probably because usnic acid decays more slowly than other components. In conclusion, snow reduced lichen RGR, but in species-specific ways. Therefore, increasing snow depthper sealong spatial and/or temporal scales likely reduces abundance and distribution of dominant mat-forming lichens in the alpine ecosystems of Scandinavia.
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Legostaeva, Yana, Anna Gololobova, and Vladimir Popov. "Geochemical Risks of Diamond Mining in Siberia." Environmental Sciences Proceedings 5, no. 1 (December 7, 2020): 4. http://dx.doi.org/10.3390/iecg2020-08907.
Повний текст джерелаАнотація:
Geochemical risk is caused by the release of hazardous chemicals to the earth surface. Primary diamond deposits are located in difficult mining and geological conditions. They represent natural geochemical anomalies associated with the mineral composition of rocks and groundwater, which contain a number of impurity elements with high toxic properties (Tl, Di, As, Cd, Hg), and increased concentrations of heavy metals (Cu, Zn, Pb, Ti, V and others). The paper presents the physical-geographical and mining-geological conditions of the diamondiferous region, where three large mining and processing divisions operate: Udachninsky, Aikhalsky and Nyurbinsky. pH, organic matter (humus), total nitrogen, and physical clay were identified in the study samples, by using potentiometric, photoelectric colorimetric, spectrophotometric methods, and pipette method for particle size analysis. Gross and mobile forms of trace elements were determined by atomic absorption and emission spectrometry. The groups of elements were identified that determined the natural and man-made anomalies. The accumulation of Cr, Ni, and Co determines the influence of kimberlite magmatism in general. Cu, Sr, and Li are accumulated in the soils of the Daldyn-Alakit diamond-bearing region. Increased concentrations of Mn and Cu are typical in the soils of the Sredne-Markhinsky diamond-bearing region. An assessment of the ecological and geochemical state of the study areas was carried out according to the indicator of total pollution (Zc), which is the sum of the excess of the concentration coefficients of chemical elements accumulating in anomalies. Areas of pollution and zones of the greatest risk are localized, which occupy up to 75% of the total area of industrial sites. They confined to quarry-dump complexes and to areas of impact of tailing dumps of processing plants.