Spring Content Research Articles

A comparative study of the quality differences and seasonal dynamics of flavonoids between the aerial parts and roots of Scutellaria barbata

IntroductionScutellaria barbata D. Don is a widely cultivated Chinese herbal medicine known for its medicinal properties. However, differences in the spatial distribution of metabolites, accumulation patterns of flavonoids, and pharmacological activities between the aerial parts and roots of S. barbata still remain unclear, posing challenges for its standardized cultivation and quality control. This study aimed to elucidate the quality differences between these plant parts and clarify their seasonal variations.MethodsThe chemical profiles were qualitatively analyzed by UPLC-QTOF-MS/MS. The accumulation patterns of total flavonoids, scutellarin and baicalin in different parts of S. barbata were quantitatively analyzed by UV and HPLC respectively. The differences of pharmacological efficacy were evaluated by antioxidant assays and CCK-8 assay.ResultsIn this research, there were 46 compounds identified in S. barbata that included 44 flavonoids. The aerial parts primarily accumulate flavonoids with 4′-hydroxyl group, while the root mainly accumulate flavonoids without this group. Additionally, the accumulation and variation of flavonoid components were seasonally dependent, with the aerial parts reaching peak content in spring during vigorous vegetative growth and the roots accumulating most flavonoids in autumn. The extracts from both parts exhibited antioxidant activity and inhibitory effects on cancer cell proliferation, with notable differences between them.DiscussionThis study provides valuable insights into the quality differences and seasonal dynamics of the different parts of S. barbata, offering a reference for standardized harvesting and quality control.

N supply and yield of sugar beet after cover cropping: effects of cover crop species and management

Despite long-time practice, the effect of cover crop (CC) cultivation on N supply and yield of subsequent sugar beet (SB) is not clear for the temperate climate of Central Europe. To elucidate, four field trials with oil radish, spring vetch, saia oat, and winter rye CCs were conducted on typical loessial soil in Germany. Mineral fertilizer N dose was varied as second factor: zero (N0) and optimum dose (Nopt). Biomass characteristics before winter, soil mineral nitrogen content in spring (SMN), and sugar yield and total plant N content of SB were measured. The CC N effect (Neff), calculated as the difference in SB N uptake after CC minus bare fallow, was computed for the periods sowing-summer (July/August) and summer-harvest. On average, sugar yield was decreased after rye and increased after vetch CC compared to bare fallow which was more pronounced under N0 than Nopt. In the period sowing-summer, characterized by a high SB N demand, Neff was close to 0 kg N ha–1 after rye and up to +30 kg N ha–1 after vetch. In contrast, Neff in summer-harvest was negative, amounting up to –80 kg N ha–1 after radish and rye. Regression analysis revealed a significant relationship between Neff in the period sowing-summer and the sugar yield difference between the cover crop treatments and bare fallow (R2 = 0.29). A multiple regression analysis (R2 = 0.68) indicated that high CC biomass combined with a large negative spring SMN difference between CC treatment and fallow caused a large yield penalty, which can be compensated for by elevated N fertilization. Moreover, CC management ensuring either a limited CC biomass or low SMN difference of CCs compared to fallow by e.g., later sowing, less vital CC species or early CC termination, will likely secure higher SB yield after CCs than fallow.

Effect of NiTi parameters on the mechanical properties of integrated braided stents

Stent insertion can serve as an effective therapy method for patients with esophageal stricture but stents with inappropriate mechanical properties lead to restenosis. To prepare a stent matching the esophageal environmental mechanics, both the NiTi spring yarn and polyester multifilament were used to produce seven kinds of stents by braiding technology. The mechanical properties of the stents were tested including compression, flexibility, and antimigration behavior. Results showed that three different parameters including spring consistency with tracks, spring content, and spring pitch altered the effective number of coils and elastic modulus, and affected the compression strength, flexibility and migration resistance of the stent. In particular, the integrated braided stent with full consistency, 12 NiTi spiral yarns, and spring pitch of 1.00 mm had the best mechanical properties among all the prototypes in this research. The compression strength, bending strength, and migration resistance were 1048.75 cN, 46.35 cN, and 3.74 N, respectively. In summary, this research presents a new preparation method for esophageal stent manufacture in the treatment of inoperable esophageal malignancies.

The Impact of Sowing Date on Soil Mineral Nitrogen Uptake Efficiency and Fertilizer N Uptake Efficiency for Winter Oilseed Rape (Brassica napus L.) in Ireland

Nitrogen (N) application on winter oilseed rape (Brassica napus L.; WOSR) in the mild Atlantic climate of Ireland is based on a soil N Index system, which does not take into account any variations in crop N demand prior to the main spring dressing of N fertilizer. This study tests whether UK- canopy management (CM) principles for oilseed rape N fertilization are applicable for oilseed rape grown in Ireland. The tested principles included (i) final N uptake of unfertilized crops will be equivalent to the soil mineral N (SMN) and N in the crop measured at the end of winter, i.e., soil N uptake efficiency (SNUpE) = 1; and (ii) the (apparent) N fertilizer N uptake efficiency, (FNUpE) is 0.6 (60%). Three years of field trials were carried out from 2017/18 to 2019/20 on different sites based on a split-plot design. Three sowing dates (SD): mid-August (SD1), End-August (SD2) and mid-September (SD3) were set as main plots and five N application strategies namely, CM standard, CM higher yield, CM low N rate, Fix225 and zero-N were set at subplot level. Results from unfertilized plots demonstrated that the ratio of final crop N uptake at harvest to the combined post-winter SMN + crop N was 1.13 and 1.14 on the two early sowing dates but 1.68 for the latest sowing. Additionally, SMN was not systematically impacted by SD, except in site-year-2. Instead, crop N content in spring had the biggest influence when calculating soil N supply for the season. More mineralization occurred through the growing season resulting in SNUpE of above 100% on all SDs. This additional available N (AAN) was quantified as 11 kgN·ha−1 on average for SD1 and SD2 and 38.6 kgN·ha−1 for SD3. FNUpE values were calculated closest to the economical optimum N rate (Nopt) and were 0.534, 0.574 and 0.486, respectively for SD1, SD2 and SD3. The Nopts at each SD were 157 kgN·ha−1 (SD1), 148 kgN·ha−1 (SD2) and 175 kgN·ha−1 (SD3) and the respective yields at each Nopt were 4.93 t ha−1, 4.90 t·ha−1 and 4.34 t·ha−1. This study shows the UK–CM principles were applicable in the mild Irish climate; however, values of SNUpE and FNUpE differ from one site-year-SD to another. Mid-August to early September sowing dates produced higher post-winter crop N content due to SMN uptake, and this results in a lower Nopt than the later SD. Sowing later led to a higher Nopt due to a combination of lower post-winter N uptake and lower FNUpE, although the effect of these factors was partially offset by a greater AAN. Measurements of SNS post-winter, an estimate of N mineralization during the growing season, together with a consideration of the sowing date helped determine the scope for reduction in fertilizer while achieving high yield and high FNUpE. Among different N rate strategies, CM standard and CM high yield were closest to the Nopt for having lower N rates at the maximum economical yield point.

Potential soil methane oxidation in naturally regenerated oak-dominated temperate deciduous forest stands responds to soil water status regardless of their age—an intact core incubation study

Key messagePotential CH4 oxidation in the top soil layer increased with decreasing soil water content in spring but was inhibited during severe summer drought in naturally-regenerated oak-dominated temperate deciduous forest stands regardless of their age. No direct effect of mineral nitrogen on soil CH4 oxidation was found. Soil CH4 oxidation in temperate forests could be reduced by extreme climatic events.ContextThe oxidation of atmospheric methane (CH4) by methanotrophic bacteria in forest soils is an important but overlooked ecosystem service.AimOur objective was to determine which factors drive variations in soil CH4 oxidation in oak-dominated temperate deciduous forest stands of different ages.MethodsSoil samples were collected in 16 stands aged 20 to 143 years in periods of high and low soil water content (SWC). The potential rate of soil CH4 oxidation was measured by incubating the first five centimetres of intact soil cores at 20 °C.ResultsSWC was the main driver accounting for variations in CH4 oxidation. In spring, a two-fold reduction in SWC greatly increased CH4 oxidation. But when the soil was dry in late summer, a further reduction in SWC led to a decrease in CH4 oxidation in the top soil layer. No direct effect of mineral nitrogen on soil CH4 oxidation was found.ConclusionsWith regard to soil CH4 oxidation, naturally regenerated forest stands contribute equally to climate change mitigation regardless of their age. Considering future climate scenarios for Europe, soil CH4 sink in temperate forests could be reduced, due to both an increase in the number of flooding episodes in spring and drier summers.

Dynamics of hydrochemical indicators and water quality of lake maloe chabachye

Pollution and drainage of surface waters is a global and national environmental problem. This article presents the results of the dynamics of hydrophysical, hydrochemical indicators and water quality in Lake Maloe Chabachye of the State National Natural Park “Burabay” by seasons for 2016-2020. The dynamics of the content of biogenic elements and heavy metals; degree and chemistry of salinity, as well as pollution index and water quality class have been studied. The research results have showed that in term of water smell, color, pH, content of dissolved oxygen, biochemical oxygen demand and general iron, the water in the lake corresponds to the maximum permitted concentration.The chemical oxygen demand, mineralization degree, the content of ammonium ions, fluorides, chlorides, sulfates, manganese, copper and zinc exceeds the maximum permitted concentration. Seasonal dynamics analysis showed darkening of water color in spring. Dissolved oxygen content in winter and spring exceeded the norm by 2.8 and 2.4 times; in summer and autumn – 2 and 2.1 times. Chemical oxygen demand in winter and summer periods exceeded the norm by 6.6 and 6.7 times; in spring and autumn – by 4.9 and 4.4 times. There was a decrease in fluoride content in spring and autumn. In winter and summer the water was salty; in spring and autumn it was brackish. Dangerous water pollution with copper cations was evaluated in spring and autumn. An excess of zinc content was noted in September. According to the pollution index (1.1-1.2), the water in the lake corresponds to the 3rd class of pollution. According to the Unified Quality Classification, the water in the lake belongs to the 4 th class (in terms of biochemical and chemical oxygen demand, the content of copper, manganese, zinc and iron –the 1 stclass; ammonium –the 2nd class; sulfates –the 4th class; magnesium, mineralization, fluorides and chlorides –the 5th class of pollution). Key words: lake, hydrophysics, hydrochemics, mineralization, pollution.

Spatial and temporal variation in soil bulk density and saturated hydraulic conductivity and its influencing factors along a 500 km transect

Soil bulk density (BD) and saturated hydraulic conductivity (Ks) are two critical soil physical parameters that affect soil water holding capacity, infiltration, carbon stocks, and many land and surface processes. Although variations in spatial and temporal BD and Ks are widely recognized and known to differ at different scales, little large-scale data is available. This study explores changes in spatial and temporal BD and Ks along a 500 km transect on the Chinese Loess Plateau (CLP). On seven different occasions, we took BD and Ks measurements in undisturbed soil samples within the surface (0–10 cm) and subsurface (10–20 cm) soil layers from August 2015 to October 2018 along this long transect. This transect covers two climate zones (subhumid and semiarid) and mainly includes five land-use types. BD and log10-transformed Ks (LogKs) exhibited weak and moderate spatial variations during different sampling periods along the long transect, respectively. The highest LogKs values of the two soil layers were observed in summer. Only BD (LogKs) in the surface soil layer of semiarid zone was significantly higher (lower). Grassland had slightly lower BD and higher Ks compared to the other land-use types. Climate had no significant effect on BD and Ks variability. Land-use type and season separately had a significant impact on BD and Ks variability, while sampling time significantly influenced both BD and Ks variability. Ks was negatively correlated with soil water content in spring, summer and autumn. In this long transect, spatial and temporal variations in BD and Ks are determined by land-use types, seasonal changes, sampling time and soil water condition. Understanding temporal BD and Ks variations and their dominant factors will help in the selection of soil physical parameters to optimize hydrological models more accurately at a regional scale.

Seasonal variation in agronomic characteristics and sugar content of cabbage genotypes

Cabbage is one of the most popular vegetables that is rich in sugars contributing to flavor and consumer acceptance; however, little information is available on the effect of genotypes and growing conditions on sugar accumulation. We assessed the seasonal variation in agronomic characteristics and free sugar content in cabbage (Brassica oleracea L. var. capitata L.) grown under open field conditions. Seventy-five cabbage genotypes were grown in the spring and autumn 2019, and their morphological characteristics and sugar concentrations were evaluated. Six cabbage types produced predominantly round-shaped heads (64 genotypes). Bright green and green were the dominant colors depending on the outer and inner leaves of the cabbage head. The most variable quantitative trait was head weight in both spring (36.9%) and autumn (49.2%). Glucose was the predominant sugar in most genotypes in both seasons. Mean glucose content in spring and autumn was 209.3 and 214.9 mg g-1 with 14.8% and 14.6% variation, respectively. Most genotypes produced higher fructose concentrations in fall than in spring. Sucrose levels showed the highest variation in both spring (36.0%) and autumn (60.5%), followed by fructose and glucose levels. Most agronomic parameters exhibited nonsignificant or negative correlations with sugar content, except the correlation of head height and width with glucose content. Fructose and glucose were positively correlated with total sugar content, while there was nonsignificant correlation with sucrose. Genotypes 160330 and 183701 produced comparably high and stable total sugar content in both seasons and can therefore be used as commercial breeding materials. We revealed a significant effect of genotype and season on cabbage agronomic characteristics and sugar content.

Quality assessment of leaf extracts of 12 olive cultivars and impact of seasonal variation based on UV spectroscopy and phytochemcial content using multivariate analyses.

Recently, focus has been made on the health-oriented uses of olive leaves, a byproduct of olive production, as a potential source of antioxidants. Oleuropein is one of the phenolic components in olive leaves known for its high antioxidant value. The main aim of the current study was constructing a model for the quality assessment of olive leaves and their potential phytochemical content and hence biological value as well. The phytochemical variation in olive leaves in both flowering (spring) and fruiting seasons (autumn) was also investigated. In this study, the leaves of 12 different olive cultivars from different geographical origins growing in Egypt were assessed for their oleuropein content, total flavonoid (TF) content and total polyphenol (Pph) content in spring and autumn via ultraviolet (UV) spectroscopy and high-performance liquid chromatography (HPLC) coupled to multivariate data analyses. The antioxidant activity of olive leaf extracts was assessed using 2,2'-diphenyl-1-picrylhydrazyl (DPPH) assay. Higher levels of oleuropein, TF and Pph content were found in spring with the highest oleuropein content in the Spanish cultivar; Manzanillo, followed by the Italian cultivar Coratina and the Egyptian Agizi Okasi (218.94, 151.58 and 122.18 mg/100 g of dried leaf extract, respectively). UV spectra was also measured and the collected data were coupled to multivariate analyses showing clustering of cultivars with common geographical origin. Our findings emphasised the influence of collection time and type of cultivar on the chemical profile of olive leaves. The model presented herein, serves for the quality assessment of olive leaves based on their phytochemical profile.

Atmospheric Concentration, Particle-bound Content, and Dry Deposition of PCDD/Fs

In this study, the atmospheric total-PCDD/Fs-WHO2005-TEQ concentrations, gas-particle partitioning, PM2.5 concentration, PM2.5-bound total PCDD/Fs-WHO2005-TEQ content and dry deposition flux in Shanghai and Nanjing were investigated from 2018-2020. In Shanghai, the total PCDD/Fs-WHO2005-TEQ concentration dropped from 0.0291 pg-WHO2005-TEQ m–3 from 2018–2019 to 0.0250 pg-WHO2005-TEQ m–3 in 2020, while in Nanjing, it dropped from 0.0423 pg-WHO2005-TEQ m–3 to 0.0338 pg-WHO2005-TEQ m–3. The average concentrations of PCDD/Fs-WHO2005-TEQ in spring and winter in Shanghai and Nanjing were 47.6% and 53.8% higher than those in summer, respectively. From 2018-2019, the average particle phase fractions of total-PCDD/Fs-WHO2005-TEQ in Shanghai and Nanjing were 50.3% and 57.5%, respectively, while in 2020, they were 47.8% and 55.1%, respectively. From 2018-2019, the average PM2.5-bound total PCDD/Fs-WHO2005-TEQ content was 0.342 and 0.493 ng-WHO2005-TEQ g–1 in Shanghai and Nanjing, respectively, while in 2020, it was 0.312 and 0.489 ng-WHO2005-TEQ g–1, respectively. In Shanghai and Nanjing, the average PM2.5-bound total PCDD/Fs-WHO2005-TEQ content in spring and winter was 77.5% and 73.2% higher than that in summer, respectively. From 2018–2019, the dry deposition flux of total-PCDD/Fs-WHO2005-TEQ was 316.3 and 460.5 pg WHO2005-TEQ m–2 month–1 in Shanghai and Nanjing, respectively, while in 2020, it was 272.5 and 368.4 pg WHO2005-TEQ m–2 month–1, respectively. The average dry deposition flux of total-PCDD/Fs-WHO2005-TEQ in spring and winter was 47.6% and 53.8% higher than that summer in Shanghai and Nanjing, respectively. The above results indicate that COVID-19 in 2020 had a positive effect on air quality improvement in PCDD/Fs. On average, more than 98.88% of the total PCDD/Fs-WHO2005-TEQ dry deposition flux was primarily contributed by the particle phase. This was attributed to the fact that dry deposition of particle phase PCDD/Fs was mainly due to gravitational settling accompanied by higher dry deposition velocities, while the gas phase PCDD/Fs were deposited mostly by diffusion at a lower dry deposition velocity. © The Author(s).

Principal Components and Classification Analysis of Manganese Content in Spring of Perennial Grassland Forage from Microecosystems of Banat Hills

The purpose of this research was to monitor the manganese (Mn) content of forage from perennial grassland microecosystems situated in the west part of Romania. Mineral and organic fertilization, since 2003, influenced the microecosystems conditions. It was used fermented sheep manure as organic fertilizer. Calamagrostis epigejos, Festuca rupicola and Trifolium repens represented mainly the Poaceae and Fabaceae families of grassland floristic matrix. It was determined the spring Mn content in the middle and at the end of May by ContrAA300 High-Resolution Continuum Source spectrometer of Analytik Jena. It was selected a number of 17 variables to compute the PC&CA model. The first three components described around 75% of total variance. The correlation coefficients for spring Mn contents of forage and mineral fertilization data were high, in 0.6 – 0.9 range. The correlation coefficients between fermented sheep manure data and spring Mn contents of forage were negatively.

Fatty acids and fat soluble vitamins content of Black Sea round goby (Neogobius melanostomus, Pallas, 1814) during fishing seasons

The aim of the present study was to determine and compare the seasonal changes in proximate composition, fatty acid profile and fat soluble vitamins content in spring and autumn goby (Neogobius melanostomus) caught from the Bulgarian Black Sea waters. Proximate composition (moisture, protein and total lipid) was determined according to AOAC (1991). Analysis of fatty acid methyl esters was performed by GC/MS system. Vitamins A, D3 and E were analysed simultaneously using RP-HPLC system. Protein was in the range 18.10 – 18.75 %, fat content was: 1.60 - 2.61g.100g-1 wet weight (w.w.). The fatty acid (FA) and vitamins contents showed significant seasonal changes. The spring goby was characterized with low saturated fatty acid (SFA, 31.8 %), high mono unsaturated fatty acids (MUFA, 34.86 %) and polyunsaturated fatty acids (PUFA, 33.34 %). In both seasons omega-3 (n-3) PUFA levels were higher than omega-6 (n-6) PUFAs. Higher amounts of alpha-tocopherol (614.9 μg.100g-1w.w.) and all-trans retinol (14.8 μg.100 g-1w.w.) were found in autumn samples, whereas cholecalciferol (4.9 μg.100 g-1w.w.) - in spring goby. Regardless of the observed seasonal changes of nutritional quality, goby species is an excellent source of analysed components, especially of n-3 PUFA, and can be recommended for healthy human diet.

Global warming affects nutrient upwelling in deep lakes

Measures to reduce lake phosphorus concentrations have been encouragingly successful in many parts of the world. After significant eutrophication in the twentieth century, nutrient concentrations have declined in many natural settings. In addition to these direct anthropogenic impacts, however, climate change is also altering various processes in lakes. Its effects on lacustrine nutrient budgets remain poorly understood. Here we investigate the total phosphorus (TP) concentrations in the epilimnion of the meromictic Lake Zug under present and future climatic conditions. Results are compared with those of other deep lakes. Data showed that TP transported from the hypolimnion by convective winter mixing was the most important source of TP for the epilimnion, reaching values more than ten times higher than the external input from the catchment. We found a logarithmic relationship between winter mixing depth (WMD) and epilimnetic TP content in spring. Warming climate affects WMD mainly due to its dependence on autumn stratification. Model simulations predict a reduction of average WMD from 78 (current) to 65 m in 2085 assuming IPCC scenario A2. Other scenarios show similar but smaller changes in the future. In scenario A2, climate change is predicted to reduce epilimnetic TP concentrations by up to 24% during warm winters and may consequently introduce significant year-to-year variability in primary productivity.

Seasonality in Nutrient Contents of Edible Green Algae Ulva compressa and Ulva fasciata from Southeast Coast of India

Seasonal variations in the proximate (protein, carbohydrate, dietary fiber, ash, moisture, lipid, amino acid and fatty acid content), mineral composition (Na, K, Ca, Mg, Fe, Zn, C, Mn) and Heavy metals content (Cd, Pb, Hg and Ni) of Ulva compressa and Ulva fasciata were investigated for all four different seasons (Spring, North east monsoon, Summer and South west monsoon) during 2015 to 2016. Data were analyzed using one- and two-way ANOVA. Significant variations in the proximate constituents were found among seasons and species. Maximum proximate and mineral composition in U. compressa are protein, carbohydrate, ash content, moisture content and lipid in northeast monsoon, dietary fiber, amino acids content and mineral content in southwest monsoon, fatty acids content in spring. Heavy metals were not detected except lead. In U. fasciata, maximum proximate and mineral composition are protein, carbohydrate, moisture content, ash content in spring season, dietary fiber in summer season, lipid and total amino acids content in northeast monsoon, fatty acids contents and mineral content in southwest season. Heavy metals were not detected except lead. U. compressa has highest protein, carbohydrate, moisture content, amino acids and mineral content as compared to U. fasciata. U. fasciata has maximum dietary fiber, ash content, lipid content and fatty acids as compared to U. compressa. In general, Northeast monsoon showed the highest proximate and mineral composition in both the algae. The present study revealed that these two edible algae have higher proximate contents which can be more ideal for food consumption for humans and animals.

Impact of projected climate change on workability, attainable yield, profitability and farm mechanization in Norwegian spring cereals

In cold-temperate climate with high soil water content in spring, the farmer often faces the choice between topsoil compaction during seedbed preparation and delayed sowing, both of which may reduce attainable cereal yield. The objective of this study was to explore whether future climate change with increasing precipitation would aggravate this dilemma. We generated weather based on historical and projected future climate in South-eastern and Central Norway. Using this weather data as input, we simulated spring workability, attainable yield, timeliness costs, and mechanization management with a workability model and a mechanization model. The projected climate changes resulted in improved workability for spring fieldwork and higher attainable yield in South-eastern Norway, and either positive or negative changes in Central Norway compared to historical conditions. We observed a general increase in variability of workability and attainable yield, and a larger risk of extremely unfavourable years in the most unfavourable scenarios in Central Norway. Changes in profitability and mechanization management were small, but followed the same pattern. The negative effects in the most unfavourable climate scenarios in Central Norway were in contrast to positive effects in earlier studies. We explained discrepancies by differences in research methods and purpose. However, simulated sowing dates of annual crops should consider workability of the soil, in terms of water content. Under worst-case conditions, in need of a certain time window to complete their spring fieldwork, farmers might adapt to impaired spring workability by working the soil at higher water content than simulated in our study. The consequence would be a larger loss of attainable yield and less profitability in the future. We anticipate that negative effects may also be expected in other northern cold-temperate regions with high soil water content in spring.

Seasonal Variability and Evolution of Glaciochemistry at An Alpine Temperate Glacier on the Southeastern Tibetan Plateau

Temperate glaciers are highly sensitive to climatic and environmental changes. Studying the chemical composition of snow, firn, and ice on temperate glaciers is important for understanding the variations in atmospheric circulation patterns, deposition conditions, and melting processes. To define snowpack chemistry and environmental significance, seven snowpacks (one snowpack in late autumn, two in winter, two in spring, and two in summer) were sampled in 2008/2009 on Baishui Glacier No. 1 in Mt. Yulong. Soluble ions in the winter snowpacks showed low values in the middle part but high values in the lower and upper parts, influenced by the atmospheric deposition of snow accumulation. The larger variations of ionic concentrations in the spring snowpacks were associated with the variable atmospheric patterns with high dust content in spring, leading to high ionic concentrations in the upper snowpack. Strong meltwater percolation resulted in quick migration and redistribution of ions for the profiles during the monsoon period. The ion elution sequence was Ca2+ > SO42− > NH4+ > K+ > NO3− > Na+ > Cl− > Mg2+. Factor analysis showed that NO3−, SO42−, NH4+ were mainly supplied by wet deposition-plus-anthropogenic input, while Cl− and Na+ originated from marine sources. Ca2+ and Mg2+ had multiple sources and the local terrestrial source was important because of locally exposed carbonate. The results suggest that chemical concentrations reflect mainly impurities supplied by atmospheric circulation and precipitation during periods of snow accumulation, as well as during the melting process.

Atmospheric PM2.5 and total PCDD/Fs-WHO2005-TEQ Level: A Case of Handan and Kaifeng Cities, China

From 2015 to 2017, the atmospheric PM2.5, the total PCDD/Fs-WHO2005-TEQ concentrations, PM2.5-bound total PCDD/Fs-WHO2005-TEQ contents, and the gas-particle partitioning of PCDD/Fs in Handan and Kaifeng were investigated. In addition, a regression analysis of the air quality index (AQI) and total PCDD/Fs-WHO2005-TEQ concentration was also studied. From 2015-2017, in Handan, the three-year average PM2.5 concentrations in spring, summer, autumn and winter were 66.9, 61.3, 74.8, and 138 µg m–3, respectively and averaged 85.3 µg m–3, which was 1.2 orders of magnitude higher than that in Kaifeng (71.1 µg m–3). The three-year average PM2.5-bound total PCDD/Fs-WHO2005-TEQ content in spring, summer, autumn, and winter in Handan were 0.88, 0.28, 0.67, and 0.72 ng WHO2005-TEQ g–1, respectively, and averaged 0.64 ng WHO2005-TEQ g–1, which was 1.1 order of magnitude higher than that in Kaifeng (0.57 ng WHO2005-TEQ g–1). The three-year average fraction of gas phase total PCDD/Fs-WHO2005-TEQ concentrations in spring, summer, autumn, and winter in Handan were 26.4%, 62.8%, 28.9%, and 3.34%, respectively, and averaged 30.4%. The three-year average fraction of gas phase total PCDD/Fs-WHO2005-TEQ concentrations in Kaifeng (34.3%) was 1.1 order of magnitude higher than that in Handan (30.4%). Positive correlations between the AQI and the total PCDD/Fs-WHO2005-TEQ concentration were found and their R2 values in 2015, 2016, and 2017 were 0.929, 0.921, and 0.876, respectively. Therefore, the AQI can be used to roughly predict the level of total PCDD/Fs-WHO2005-TEQ in ambient air through the use of a regression equation in these two cities.

Long-range transport of atmospheric lead reaching Ny-Ålesund: Inter-annual and seasonal variations of potential source areas

Atmospheric particulate matter (PM10) was collected at Ny-Ålesund (Svalbard Islands, Norwegian Arctic) during spring and summer from 2010 to 2014 and analysed for lead content, enrichment factor and isotopic composition (208Pb/206Pb and 207Pb/206Pb). It was found that atmospheric lead was mainly of anthropogenic origin and neither its mean concentration, nor its isotopic composition was subjected to significant inter-annual differences (p-value > 0.1). Seasonal differences in both lead content and isotopic compositions occurred (p-value < 0.001), with the exception of 2013 samples. Lead content in spring was higher than in summer. Isotopic analysis indicated that mining and smelting activities in the Rudny Altay region (Central Eurasia), as well as industrial emission in north-eastern North America, were the main sources of atmospheric lead in spring and summer, respectively. During 2013, no significant differences between the two seasons were found (p-value > 0.3), showing a prolonged influence of Eurasian sources also in summer. The results obtained by the Pb isotopic composition were corroborated by a back-trajectory cluster analysis of air-masses reaching the sampling site.

The Effects of Season and Sex on the Nutritional Quality of Muscle Types of Blue Crab Callinectes sapidus and Swimming Crab Portunus segnis

The effects of season and sex on the nutritional quality of muscle types (lump crab meatLCM, claw crab meat-CCM) of swimming crab (Portunus segnis) and blue crab (Callinectes sapidus) were investigated. Carapace width, carapace length and total weight of both crab species were measured. High protein content in spring and low protein content in autumn were observed for both crab species. The levels of lipid content of both crab species were found to be similar. Higher lipid contents in spring and winter, lower lipid contents in summer and autumn for both sexes were found. Although both crab species contain small amounts of fat, they are good sources of n-3 PUFA content (especially EPA and DHA) for all seasons regardless of sex and muscle types.

Seasonal and annual variation in the diet of brown bears Ursus arctos in the boreal forest of southcentral Sweden

Understanding a species' feeding ecology is essential for successful management and conservation, because food abundance can influence body mass, survival, reproductive success, movements, and habitat use. We describe annual and seasonal variations in the diet of brown bears Ursus arctos in southcentral Sweden, based on analysis of 527 fecal samples from 1994–1996 and 2000–2001. There was distinct seasonal variation in most of the 26 food items we documented. Ungulates, predominantly moose Alces alces, and insects comprised most of the estimated dietary energy content in spring and summer. Insects were represented almost entirely by ants, of which Formica spp. and Camponotus herculeanus were the most common. During autumn, berries dominated the diet. The most important berry species were bilberry Vaccinium myrtillus, crowberry Empetrum hermaphoditum and lingonberry V. vitis‐idaea. We determined berry availability by inventorying 308 random plots three times for two consecutive years. These three berries occurred with great spatial, seasonal and annual variation in abundance. The bears showed the strongest positive preference for bilberries, a lesser positive preference for crowberries, but no preference for lingonberries. The proportion of berries in the autmn diet was stable between years, but the relative importance of the species changed, indicating that bears switched to crowberries when bilberries were less abundant. The effects of predicted future climatic change might have severe effects on the availability of the berries, which is the only important food available for fat acquisition prior to hibernation.