Sampling Depth Research Articles

Marine Plankton during the Polar Night: Environmental Predictors of Spatial Variability.

We studied the spatial patterns of the planktonic ecosystems at two Arctic sites strongly affected by Atlantic Inflow (FS, the Fram Strait; and BS, the Barents Sea). A high degree of similarity in the bacterial abundance (mean: 3.1 × 105 cells mL-1 in FS vs. 3.5 × 105 cells mL-1 in BS) was found, while other plankton characteristics were different. Bacterial biomass reached a maximum in BS (3.2-7.9 mg C m-3), while viral abundances tended to be higher in FS (2.0-5.7 × 106 particles mL-1). Larger bacterial cells were found in BS, suggesting the presence of different bacterial populations at both locations. The virus-to-bacteria ratio was significantly higher in FS than in BS (13.5 vs. 4.7). Chlorophyll a concentration was extremely low (<0.25 mg m-3). The highest zooplankton abundance was in the surface layer (919 individuals m-3 in FS vs. 602 ind. m-3 in BS). Zooplankton biomass strongly varied (1-39 mg C m-3), with the maximum in BS. High proportions of boreal taxa in the total zooplankton abundance indicate the Atlantification of pelagic ecosystems in the Arctic. Plankton indicators are correlated with temperature, salinity, and sampling depth. Strong intercorrelations were found between major plankton groups, suggesting tight links in the studied plankton ecosystems.

Estuarine Sediment Microbiomes from a Chronosequence of Restored Urban Salt Marshes.

Salt marshes play an important role in the global nutrient cycle. The sediments in these systems harbor diverse and complex bacterial communities possessing metabolic capacities that provide ecosystem services such as nutrient cycling and removal. On the East Coast of the USA, salt marshes have been experiencing degradation due to anthropogenic stressors. Salt marsh islands within Jamaica Bay, New York City (USA), are surrounded by a large highly urbanized watershed and have declined in area. Restoration efforts have been enacted to reduce further loss, but little is known about how microbial communities develop following restoration activities, or how processes such as nitrogen cycling are impacted. Sediment samples were collected at two sampling depths from five salt marsh islands to characterize the bacterial communities found in marsh sediment including a post-restoration chronosequence of 3-12 years. We used 16s rRNA amplicon sequencing to define alpha and beta diversity, taxonomic composition, and predicted metabolic profile of each sediment sample. We found significant differences in alpha diversity between sampling depths, and significant differences in beta diversity, taxonomic composition, and predicted metabolic capacity among the five sampling locations. The youngest restored site and the degraded natural sampling site exhibited the most distinct communities among the five sites. Our findings suggest that while the salt marsh islands are located in close proximity to each other, they harbor distinct bacterial communities that can be correlated with post-restoration age, marsh health, and other environmental factors such as availability of organic carbon. IMPORTANCE: Salt marshes play a critical role in the global nutrient cycle due to sediment bacteria and their metabolic capacities. Many East Coast salt marshes have experienced significant degradation over recent decades, thought largely to be due to anthropogenic stressors such as nitrogen loading, urban development, and sea-level rise. Salt marsh islands in Jamaica Bay (Queens/Brooklyn NY) are exposed to high water column nitrogen due to wastewater effluent. Several receding marsh islands have been subjected to restoration efforts to mitigate this loss. Little is known about the effect marsh restoration has on bacterial communities, their metabolic capacity, or how they develop post-restoration. Here, we describe the bacterial communities found in marsh islands including a post-restoration chronosequence of 3-12 years and one degraded marsh island that remains unrestored. We found distinct communities at marsh sites, despite their geographic proximity. Differences in diversity and community composition were consistent with changes in organic carbon availability that occur during marsh development, and may result in differences in ecosystem function among sites.

Solid-State Surface Patterning on Polymer Using the Microcellular Foaming Process

This study proposes a novel process that integrates the molding and patterning of solid-state polymers with the force generated from the volume expansion of the microcellular-foaming process (MCP) and the softening of solid-state polymers due to gas adsorption. The batch-foaming process, which is one of the MCPs, is a useful process that can cause thermal, acoustic, and electrical characteristic changes in polymer materials. However, its development is limited due to low productivity. A pattern was imprinted on the surface using a polymer gas mixture with a 3D-printed polymer mold. The process was controlled with changing weight gain by controlling saturation time. A scanning electron microscope (SEM) and confocal laser scanning microscopy were used to obtain the results. The maximum depth could be formed in the same manner as the mold geometry (sample depth: 208.7 μm; mold depth: 200 μm). Furthermore, the same pattern could be imprinted as a layer thickness of 3D printing (sample pattern gap and mold layer gap: 0.4 mm), and surface roughness was increased according to increase in the foaming ratio. This process can be used as a novel method to expand the limited applications of the batch-foaming process considering that MCPs can impart various high-value-added characteristics to polymers.

Effect of Soil Organic Mulching Combined with Aeration Treatment on Soil Quality, Nutrients Content, and Lei Bamboo Shoot Production

Lei bamboo cultivation is an important economic activity in the Zhejiang province of China. However, extensive management practices such as organic mulching aimed at optimizing Lei bamboo production usually have a long-term negative impact on soil pH. Thus, it is important for novel management practices that consider not only bamboo production but also soil quality to be developed. In this study, we evaluated the effect of four conditions: organic mulching combined with aeration (MA), organic mulching and no aeration (MNA), aeration and no mulching (NMA), and control treatment (CK) on soil quality parameters and Lei bamboo shoot production. The Lei bamboo stands have been receiving similar treatments for 3–4 years, but for this study, organic mulch materials (rice husks, stalks, bamboo leaves, non-living plant biomass materials and plants biochar) were reapplied in October 2021 and soil sampling was done in April 2022. Our results showed that the average oxygen content at a sampling depth of 10 cm in CK, MA, and NMA was 21.6%, 21.7%, and 20.7%, respectively. However, when mulching was applied without aeration (MNA), soil oxygen content and pH were decreased by 6.3% and 0.7 units compared to CK. Moreover, for this treatment soil pH was as low as 4.28 at a depth of 30 cm. Nevertheless, when mulching was applied together with aeration (MA), all soil quality parameters, including the contents of organic matter and nitrogen were significantly increased (p &lt; 0.05). For MA, soil pH was generally &gt; 5.0 even at a depth of 30 cm. For all the treatment plots, the number of bamboo shoots that were produced after one month of treatment followed the sequence MA (591.0) &gt; MNA (554.3) &gt; NMA (305.7) &gt; CK (53.3). Even though NMA and MNA treatments both improved bamboo growth by providing the required nutrients, we recommend the combined application of mulching and aeration (MA) for long-term Lei bamboo plantation management since the combination has the potential to improve nutrient supply and bamboo growth while retarding soil acidification.

Measurement of the mean central optical depth of galaxy clusters via the pairwise kinematic Sunyaev-Zel’dovich effect with SPT-3G and DES

We infer the mean optical depth of a sample of optically-selected galaxy clusters from the Dark Energy Survey (DES) via the pairwise kinematic Sunyaev-Zel'dovich (kSZ) effect. The pairwise kSZ signal between pairs of clusters drawn from the DES Year-3 cluster catalog is detected at $4.1 \sigma$ in cosmic microwave background (CMB) temperature maps from two years of observations with the SPT-3G camera on the South Pole Telescope. After cuts, there are 24,580 clusters in the $\sim 1,400$ deg$^2$ of the southern sky observed by both experiments. We infer the mean optical depth of the cluster sample with two techniques. The optical depth inferred from the pairwise kSZ signal is $\bar{\tau}_e = (2.97 \pm 0.73) \times 10^{-3}$, while that inferred from the thermal SZ signal is $\bar{\tau}_e = (2.51 \pm 0.55) \times 10^{-3}$. The two measures agree at $0.6 \sigma$. We perform a suite of systematic checks to test the robustness of the analysis.

Distribution of tritium-helium groundwater ages in a large Cenozoic sedimentary basin (North German Plain)

The travel time of groundwater plays a major role in the understanding of hydrogeological systems; however, large data sets necessary for regional studies of groundwater age are rare. In this study, a unique large data set of groundwater samples analysed for tritium and helium isotopes collected over the last 20 years from Cenozoic aquifers of the North German Plain is explored. Hereby, the variety of natural and technical influences on the tritium-helium age, including screen depth and length, groundwater recharge rate and climatic effects, are investigated. To a sampling depth of ~40 m below ground level, the median tritium-helium age increases almost linearly with depth, reaching a maximum of 40 years. Below, the portion of older, tritium-free water rises. The tritium-helium ages of the tritium-bearing portion increase only slightly to a maximum of about 46 years. The depth distribution of the tritium-helium age shows a dependency on groundwater recharge rates. Considering the same depth level, younger ages are related to higher groundwater recharge rates as compared to groundwater that infiltrated in areas with lower recharge rates. This is especially observed for shallow depths. Tritium-helium ages younger than 40 years are reflected well in the atmospheric tritium input curves, while deviations from it can be related to anthropogenic influences such as input from nuclear power plants and irrigation with deep, tritium-poor groundwater. The regional distribution for shallow wells indicates increasing tritium-helium ages from west to east, corresponding to decreasing groundwater recharge rates due to the more continental climate in the east.

Quantitative depth‐dependent analysis using the inelastic scattering backgrounds from X‐ray photoelectron spectroscopy and hard X‐ray photoelectron spectroscopy

The inelastic scattering contribution to an X‐ray photoelectron spectrum (XPS) reflects the distribution of elements within the sample depth. Varying the energy of the incident photons changes the inelastic scattering contribution. We present a standardless, automated method that exploits this change to enable compositional analysis within the XPS information depth (also known as amount of substance, AOS3λ). In this method, the photoelectron intensities observed using two or more X‐ray photon energies are normalised using correction factors. These correction factors are derived to determine the AOS3λ from the inelastic scattering signals collected from different samples. The AOS3λ are then compared with the ratio of the elastic XPS peak intensities calculated for different sample depths to find the layer thickness. The method has been applied to analyse spectra collected from thin amorphous carbon films to yield quantitative, standardless and automated XPS analysis.

Analytical applications of smartphones for agricultural soil analysis

Soil is one of the most important farming resources. Appropriate managing of its quality promotes productive and sustainable agriculture. The valuable farm practice in soil quality managing is based on regular soil analysis with the aim of determining the exact amount of nutrients or other chemical, physical, and biological soil properties. Soil analysis usually requires sample collection at the desired sampling depth followed by sample delivery to chemical laboratories. However, laboratory analyses are resource-intensive and costly, and require a lot of time, effort, and equipment. A low-cost, fast, and effective alternative for soil quality control is the application of smartphones to perform chemical analyses directly in the field or on the farm. In this paper, an overview of recent developments on smartphone-based methodologies for agricultural purposes and portable evaluation of soil quality and its properties is presented. The discussion focuses on recent applications of smartphone-based devices for the determination of basic soil parameters, content of organic matter, mineral fertilizers, and organic or inorganic pollutants. Obvious advantages of using smartphones, such as convenience and simplicity of use, and the main shortcomings, such as relatively poor precision of the results obtained, are also discussed. The general trend shows the huge interest from researchers to move the technology into the field with the aim of providing cost-effective and rapid soil analysis. This paper can broaden the understanding of using smartphones for chemical analysis of soil samples, as it is a relatively new area and is expected to be developed rapidly.Graphical

Archaeological soil from Roman occupational layers can be differentiated by microbial and chemical signatures

IntroductionSoil at the Roman site of Vindolanda (Northumberland, UK) provides excellent preservation of wooden artefacts including Roman writing tablets.MethodsIn this study we examined chemical and microbial signature changes within varied occupation contexts of archaeological soil. Analysis included investigating elemental composition, sterol biomarkers, bacterial diversity and community structures from excavation trenches at Vindolanda using pXRF, GC-MS and 16S rRNA gene amplicon sequencing. Samples were taken from varying depths starting at topsoil and working down through layers of Roman occupation including one cavalry stable floor, two infantry barracks and a cook house, and layers which contained Roman writing tablets.Results and DiscussionThe chemical results indicate that areas where wooden artefacts were found had increased soil moisture which was also correlated with specific chemical conditions including shifts in iron, sulphur and phosphorous concentration. Steroid biomarkers indicate the presence of faecal matter in layers, supporting occupation descriptions. Overall microbial diversity did not change across the depth profile but was correlated with soil moisture. Anaerobic soils associated with more optimal preservation differed to other soils with increases in Firmicutes, Proteobacteria, Campilobacterota and Bacteroidota observed. Microbial community structure and putative function as revealed by PICRUSt2 is linked to occupation usage rather than depth of samples with laminated floor layers differing from turf structures. Understanding the complex processes within archaeological soil can help us to understand dynamics of decomposition and preservation. In addition, the apparent preservation of the environmental microbial community as well as the artefacts themselves allows us to understand the microbial environments of the past, how they relate to the present and what this means for our changing environments in the future.

First emerging pollutants profile in groundwater of the volcanic active island of El Hierro (Canary Islands)

Emerging pollutants (EPs) are substances present in wastewater that have not been studied, previously, leading to ambiguity in regulations for their presence in water resources. Territories that are highly dependent on groundwater resources are at a high risk of suffering the consequences of EP contamination due to their dependence on good quality groundwater for agriculture, drinking, and other uses. A relevant example is El Hierro (Canary Islands), which was declared a biosphere reserve by the UNESCO in 2000 and is almost completely powered by renewable energies. Using high performance liquid chromatography-mass spectrometry, the concentrations of 70 EPs were assessed at 19 sampling points on El Hierro. The results indicated that no pesticides were present in groundwater; however, varied concentration levels of ultraviolet (UV) filters, UV stabilizers/blockers and pharmaceutically active compounds (PhACs) were found, with La Frontera being the most contaminated municipality. With regard to the different installation types, piezometers and wells were the ones showing the highest concentrations for most EPs. Interestingly, the depth of sampling correlated positively with EP concentration, and four different clusters virtually dividing the island into two areas could be identified based on the presence of each EP. More studies should be performed to ascertain why a few of the EPs showed considerably high concentrations at different depths. The results obtained highlight the need to, not only implement remediation measures once EPs have reached the soil and aquifers, but also to avoid their incorporation into the water cycle via homes, animal husbandry, agriculture, industry, and wastewater treatment plants (WWTPs).

Compositional characteristics and indication of n-fatty acids in alpine meadow plants and soils

AimTo explore the distributions and indication of n-fatty acids in the plants and soils from alpine meadow, and how n-fatty acids in plants and soils are associated. MethodsThe plant (grass, herb, and shrub) and soil samples were collected from alpine meadow in the Qinghai-Tibet Plateau, and the compositional characteristics of n-fatty acids were analyzed using GC-MS. Results and conclusionn-Fatty acids ranging from C6 to C28 were identified, C16 was the most abundant fatty acid in most plants, which contributed between 39.1% and 74.2% to total n-fatty acids; the most abundant fatty acid in soils was C15, which contributed between 72.1% and 89.1% to total n-fatty acid. The total n-fatty acid content of Artemisia hedinii and the long chain n-fatty acid content of Ajuga lupulina were the highest, while the total and long chain n-fatty acid content of Saxifraga tangutica were the lowest. The contents of C20, C22, C24 and C26 in indicative plants of degradation and typical dominant plants (Festuca sinensis, Elymus nutans, Poa crymophila, Kobresia humulis, Kobresia pygmaea) were higher than other long chain n-fatty acids (C ≥ 20). The n-fatty acids content of the plants in degraded alpine meadow were higher than that in non-degraded alpine meadow except C6, C23, C25 and C27. The total n-fatty acids content of plants and soils in degraded alpine meadow were higher than that of non-degraded meadow. The n-fatty acids content in soils were decreased with the increasing depth of sampling except C15. The positive correlation of long chain n-fatty acids content in soils and plants was strongly significant (p < 0.001, R2 = 0.926). The compositional characteristics of n-fatty acids in plants and soils were similar. Therefore, the source of the long chain n-fatty acids in the soil might be deduced from native vegetation.

In-situ trace elements and sulfur isotopic analyses of stibnite: Constraints on the genesis of Sb/Sb-polymetallic deposits in southern China

The Xiangzhong metallogenic province (XZMP), the largest polymetallic mineralization province in southern China, is known for its large number of Sb and Sb-polymetallic deposits (>100). In this study, detailed microscope observation, trace element, and sulfur isotopic analyses were performed on stibnite from the Xikuangshan, Woxi, and Banxi deposits in the XZMP to constrain the ore genesis.Stibnite from three deposits appears similar under backscattered electron imaging and has similar major elements contents. Detectable trace elements in stibnite are Fe, Cu, Zn, As, and Pb. Base metals (Cu, Pb, and Zn) are enriched in stibnite from the Woxi deposit but are depleted in stibnite from the Xikuangshan and Banxi deposits. Gold is detectable only in stibnite from the Woxi deposit. Cu, As, and Pb mainly occur as solid solutions within the crystal lattice in stibnite, while micro-scale inclusions of Fe- and/or Zn-rich phases are also observed. The δ34S values of stibnite from three deposits are distinct but with narrow ranges: +6.8 to +10.2 ‰; +5.5 to +6.5 ‰; −4.2 to +0.1 ‰ for the Xikuangshan, Banxi, and Woxi deposits, respectively. The δ34S values of stibnite suggest that the underlying basement rocks are the potential source of sulfur for the Sb mineralization in the Xikuangshan and Banxi districts while sulfur for the Sb mineralization of the Woxi district may have originated from a deep magmatic source. In addition, a positive trend between the δ34S values of stibnite and sampling depth suggests an input of the 34S-rich basin brine during the mineralization in the Woxi district.We propose a genetic model for the Sb mineralization in the XZMP: Fluids rich in Sb, Au, W, Cu, Pb, and Zn related to igneous activities ascended via regional deep faults and mixed with 34S-rich basin brine. Ore minerals of Sb, Au, and W were deposited within structural traps resulting in the Woxi-type deposits. The basement-derived deep fluids driven by orogenic leached Sb and related metals from the basement metamorphic rocks, which migrated via the regional faults and mixed with cold near surface meteoric water to form the Xikuangshan-type deposits.

Soil mineral nitrogen content and grain yield with enhanced efficiency fertilizers in maize

AbstractUrea is the most common N fertilizer worldwide, but N from urea breakdown can be easily lost through ammonia (NH3) volatilization, ammonium (NH4+) nitrification, nitrate (NO3−) denitrification or NO3−–leaching processes. Enhanced efficiency fertilizers (EEFs) are formulated to minimize N losses and maximize plant N uptake and crop yields. The capacity of urea EEFs (urea with urease inhibitor, nitrification inhibitor, both urease and nitrification inhibitors, and polymer‐coated) to maintain N in the soil profile throughout the growing season was determined by the analysis of [NH4+–N] and [NO3−–N] in three top‐soil depth increments at three dates in three seasons of no‐till maize (Zea mays L.). Surface‐applied EEFs, untreated urea, and injected urea ammonium nitrate (UAN) were compared at an application rate of 168 kg N ha−1. Within and across years, soil [NO3−–N] and [NH4+–N] typically decreased with depth and time since urea application. Among the EEFs, only a polymer‐coated urea produced greater [NO3−–N] and [NH4+–N] at several sampling dates and depths, and greater grain yields than untreated urea across the 3 yr. Nonetheless, the polymer‐coated urea resulted in significantly greater fertilizer use efficiency (FUE) than untreated urea in only 1 of 3 yr. Several EEFs increased grain yields compared to untreated urea each year, but FUE generally was similar to that with untreated urea. Environmental conditions influenced the effectiveness of EEFs in improving soil mineral N availability and increasing grain yield.

Method of measuring the temperature of wood exposed to fire with type K thermocouples

The study of wood behaviour in the event of fire is of increasing interest in the civil engineering field. Wood is one of the most prevalent combustible materials used in buildings. However, this material is protected by the char layer during fire exposure. It can slow down the charring rate of timber in fire and protect the internal wood structure. In fire tests, it is very important to use the most effective method of measuring the temperature of wood. In this paper, experimental tests are performed in furnaces and the charring rate is determined by measuring the depth of the charred part of timber at the end of the time. This approach is compared to direct measurements given by thermocouples positioned at different depths in the wood sample in different directions (radial, longitudinal, and tangential). All test samples were tested in a furnace where three surfaces of the sample were exposed to ISO-834 fire standards. The comparison between the two methods of measuring the charring rate allowed us to evaluate the accuracy of the thermocouple measurements according to the implementation adopted in the sample. Besides, the factors affecting the temperature measurement results are also mentioned in this study such as the position of the thermocouple in the wood, the size of the measuring sample and the size of the thermocouple.

Efficiency of genotyping by sequencing in inferring genomic relatedness and molecular insights into fat tail selection in Tunisian sheep.

In developing countries, the use of simple and cost-efficient molecular technology is crucial for genetic characterization of local animal resources and better development of conservation strategies. The genotyping by sequencing (GBS) technique, also called restriction enzyme- reduced representational sequencing, is an efficient, cost-effective method for simultaneous discovery and genotyping of many markers. In the present study, we applied a two-enzyme GBS protocol (PstI/MspI) to discover and genotype SNP markers among 197 Tunisian sheep samples. A total of 100 333 bi-allelic SNPs were discovered and genotyped with an SNP call rate of 0.69 and mean sample depth 3.33. The genomic relatedness between 183 samples grouped the samples perfectly to their populations and pointed out a high genetic relatedness of inbred subpopulation reflecting the current adopted reproductive strategies. The genome-wide association study contrasting fat vs. thin-tailed breeds detected 41 significant variants including a peak positioned on OAR20. We identified FOXC1, GMDS, VEGFA, OXCT1, VRTN and BMP2 as the most promising for sheep tail-type trait. The GBS data have been useful to assess the population structure and improve our understanding of the genomic architecture of distinctive characteristics shaped by selection pressure in local sheep breeds. This study successfully investigates a cost-efficient method to discover genotypes, assign populations and understand insights into sheep adaptation to arid area. GBS could be of potential utility in livestock species in developing/emerging countries.

English

The insufficiency of nutrients in the soils has been identified as one of the factors that have affected the productivity of crops. An investigation was carried out to assess the trophic level of soil in the region. Using a non-probability sampling technique, a total of 70 representative surface soil samples were collected between February and April, 2021. The sampling depth ranged from 0 to 30 cm, according to the root length of the crop. The collected soil samples were analyzed to assess the pH, EC, OM, available macronutrients, and micronutrients. The macronutrients were determined using a flame photometer, and micronutrients were determined with ICP-OES. The organic matter status was low in Trenabougou soils. The soils are moderately acidic in reaction (pH 5.84) with low soluble salt content (EC 0.27 dS/m). Some macronutrients were low or medium in fertility status. The nitrogen, potassium, and magnesium nutrient index values were below 1.25, indicating low fertility status. Nevertheless, sulphurous and calcium were found at medium fertility levels with a nutrient index of 1.87 and 2.17. The concentrations of micronutrients like iron, copper, and zinc were high in soils. Nevertheless, nickel, manganese, and boron were in the limited range suitable for plant growth. Key words: Available NPK, Nutrients, Nutrient Index, Siby, Mali.

Investigating Environmental Matrices for Use in Avian Influenza Virus Surveillance-Surface Water, Sediments, and Avian Fecal Samples.

Surveillance of avian influenza viruses (AIV) in wild water bird populations is important for early warning to protect poultry from incursions of high-pathogenicity (HP) AIV. Access to individual water birds is difficult and restricted and limits sampling depth. Here, we focused on environmental samples such as surface water, sediments, and environmentally deposited fresh avian feces as matrices for AIV detection. Enrichment of viral particles by ultrafiltration of 10-L surface water samples using Rexeed-25-A devices was validated using a bacteriophage ϕ6 internal control system, and AIV detection was attempted using real-time RT-PCR and virus isolation. While validation runs suggested an average enrichment of about 60-fold, lower values of 10 to 15 were observed for field water samples. In total 25/36 (60%) of water samples and 18/36 (50%) of corresponding sediment samples tested AIV positive. Samples were obtained from shallow water bodies in habitats with large numbers of waterfowl during an HPAIV epizootic. Although AIV RNA was detected in a substantial percentage of samples virus isolation failed. Virus loads in samples often were too low to allow further sub- and pathotyping. Similar results were obtained with environmentally deposited avian feces. Moreover, the spectrum of viruses detected by these active surveillance methods did not fully mirror an ongoing HPAIV epizootic among waterfowl as detected by passive surveillance, which, in terms of sensitivity, remains unsurpassed. IMPORTANCE Avian influenza viruses (AIV) have a wide host range in the avian metapopulation and, occasionally, transmission to humans also occurs. Surface water plays a particularly important role in the epidemiology of AIV, as the natural virus reservoir is found in aquatic wild birds. Environmental matrices comprising surface water, sediments, and avian fecal matter deposited in the environment were examined for their usefulness in AIV surveillance. Despite virus enrichment efforts, environmental samples regularly revealed very low virus loads, which hampered further sub- and pathotyping. Passive surveillance based on oral and cloacal swabs of diseased and dead wild birds remained unsurpassed with respect to sensitivity.

Effect of Anthropogenic Type and Depth on Microplastic Abundance in Mahakam River Water, Samarinda City

Mahakam is the second longest river in Indonesia and it functions as a source of raw water for drinking and other essential activities for the Samarinda people. Furthermore activities in the watershed generate solid waste such as plastic, which enters the waters and is potentially degraded into microplastics. There is a possibility that the presence of microplastics is affected by anthropogenic types along the river. Therefore, this research aims to determine the effect of anthropogenic type and river depth on the microplastic abundance in the Mahakam River. The samples were taken using an integrated approach at 3 depths, namely 0.5, 1, and 1.5 m, in 2 locations with different anthropogenic types. The sampling points include Kampung Tenun and Bukuan Villages, which represented densely populated and non-populated areas, respectively. The water collected was prepared with the following steps, which include filtration with 180 μm nylon, elimination of organic matter, density separator, and final filtration. Microplastic samples were identified based on the type, color, size, and type of polymer using a microscope and FTIR. The results show that there are 3 types of microplastics, 4 colors, and 5 size categories dominated by fiber type, black, and the smallest size, respectively. There are differences in abundance in Kampung Tenun and Bukuan Villages, namely 91 particles/L and 71 particles/L, indicating the effect of the anthropogenic type. Sampling depth also affects abundance, hence, the greater the depth, the lower the abundance value. It was also discovered that anthropogenic type and depth factors influence the identified polymer types. Nylon and nitrile polymer types were found at 2 locations and 3 sampling depths, but PVC, PETE, and PS were only found at certain locations. Furthermore, Bukuan Village, with a greater environmental factor value, has a smaller abundance than Kampung Tenun Village. HIGHLIGHTS Anthropogenic types affect the microplastic abundance in Mahakam River water Sampling depth affects the microplastic abundance in Mahakam River water Microplastics are found in Mahakam River water in 3 forms, 4 colors, and 5 types of polymers, with a size range of 180 - 5000 µm Environmental factors affect the microplastic abundance in Mahakam River water GRAPHICAL ABSTRACT

Responses of microbial community to geochemical parameters on vertical depth in bioheap system of low-grade copper sulfide

Monitoring of the microbial community in bioleaching system is essential for control process parameters and enhance the leaching efficiency. Due to the difficulty of sampling, microbial distribution, community succession and bioleaching activity along the vertical depth of bioleaching heaps remain unresolved. This study investigated the geochemical parameters and microbial community structure along a depth profile in a bioleaching heap and leachate. 80 ore samples at different heap depths and 9 leaching solution samples from three bioheaps of Zijin Copper Mine were collected. Microbial composition, mineral types and geochemical parameters of these samples were analyzed by 16S rRNA high-throughput sequencing and a series of chemical measurement technologies. The results revealed that the pH, Cu, Fe and the total sulfur contents were the major factors shaping the composition of the microbial communities in the bioleaching system. The extent of mineral oxidation increased as the sample depth increases, followed by the increasing of sulfur oxidizers. The abundance of sulfur and iron oxidizers including members of Acidithiobacillus, Sulfobacillus and Acidiferrobacter were significantly higher in the leaching heap than in the leaching solution, meanwhile, they showed strong positive interactions with other members within the same genera and iron oxidizer Leptospirillum and Ferroplasma. Besides, Acidithiobacillus negatively interacted with heterotrophs such as Sphingobium, Exiguobacterium, Brevundimonas and so on. On the contrast, members of Leptospirillum and unclassified Archaea were significantly abundant in the leaching solution and revealed strong interactions with members of Thermoplasmatales. The main conclusion of this study, especially the leaching potential of microorganisms prevailing in bioheaps and their relationships with geochemical factors, provides theoretical guidance for future process design such as the control of processing parameters and microbial community in heap leaching.

A simple multilevel sampler for synchronous collection of stratified waters.

Stratified water collection plays a crucial role in water quality monitoring, as most water bodies are not perfectly mixed systems. In order to precisely collect stratified waters, we developed an inexpensive, simple, and high-resolution sampler to simultaneously collect and measure physical and chemical parameters along vertical water profiles. The water sampler predominantly consists of two parts: (1) an apparatus for measuring sampling depth below the water and (2) water sampling units secured below the water. Proof of concept water sampling was performed in Caohai wetland (Southwest China) at 40cm intervals, as sampling depth and interval are adjustable. Stratified waters in four sampling sites were characterized by markedly different levels of major and trace elements as well as physicochemical parameters. Results indicate this simple multilevel sampler to be a cheap, precise, and portable option for simultaneously collecting water samples at different depths in a wide array of water body types.