Composite Fingerprints Research Articles

Comparison of Polysaccharide Profiles of Different Seaweeds Based on Ion Chromatography and Ultrahigh‐Performance Liquid Chromatography

ABSTRACTIn traditional Chinese medicine research, seaweeds used for drug and health food development mainly refer to Sargassum pallidum (Turn.) C. Ag. (SP) and Sargassum fusiforme (Harv.) Setch. (SF). In the Chinese Pharmacopoeia, polysaccharides are the main quality control indicators. The total sugar content is determined by the anthrone–sulfuric acid method to evaluate the quality of seaweeds. However, this method cannot reflect the structural characteristics of seaweed polysaccharides and cannot distinguish among different seaweed varieties. Given this, to comprehensively evaluate the quality of different seaweeds, this study conducted a thorough analysis of the primary structure of polysaccharides in 11 batches of SF and 7 batches of SP. The neutral sugar content was determined by the anthrone–sulfuric acid colorimetric method, weight average molecular weight (Mw) by high‐performance size exclusion chromatography coupled with multi‐angle laser light scattering and refractive index detector method, sulfate content by ion chromatography and monosaccharide composition by ultrahigh‐performance liquid chromatography method, while also using professional software for statistical and similarity analysis. The results showed significant differences (p < 0.05) in neutral sugar content and Mw between S. fusiforme polysaccharides and S. pallidum polysaccharides, which can be used to distinguish SF and SP. The monosaccharide composition fingerprint was analyzed using chemometric methods, and it was found that fucose and glucose could serve as differential markers to distinguish SF and SP. This study further deepens the understanding of polysaccharides in seaweeds and more comprehensively evaluates the quality of different seaweeds.

Confluence-based suspended sediment fingerprinting: an exploratory approach to determining source to sink sediment contributions in the Tsitsa River catchment, Eastern Cape, South Africa

ABSTRACT In the Tsitsa River catchment of the Eastern Cape Province, South Africa, concerns regarding the sedimentation of a proposed large, multipurpose, in-channel water storage scheme prompted investigations of sub-catchment suspended sediment loads and yields. Confluence-based fingerprinting and source apportionment was undertaken to explore whether this simple approach could identify relative sub-catchment contributions to downstream sediment loads, supplementing modelling and direct sampling. In November 2018, fine sediment sequestered in bed substrates was sampled above and below confluences, using a resuspension technique. The < 63 µm sample fraction underwent analysis of mineral magnetic properties, gamma emitting radionuclide activities and geochemistry to identify suitable tracers. Conservatism and range tests were used to select different combinations of composite fingerprints at seven confluences. Bivariate source apportionment using an unmixing model showed that the approach could be used as a preliminary means of determining relative sub-catchment sediment contributions. Catchment characteristics such as geology and land cover, as well as land tenure and management, were considered as explanatory factors for the difference in sediment contributions. The results for most sub-catchments were broadly similar to those from other studies. Shortcomings of this approach included the reliance on a single sampling effort, and uncertainty associated with sub-catchment sediment transport and residence times.

Neural Network-Based Filter Design for Compressive Raman Classification of Cells.

Cell-based therapies are bound to revolutionize medicine, but significant technical hurdles must be overcome before wider adoption. In particular, nondestructive, label-free methods to characterize cells in real time are needed to optimize the production process and improve quality control. Raman spectroscopy, which provides a fingerprint of a cell's chemical composition, would be an ideal modality but is too slow for high-throughput applications. Compressive Raman techniques, which measure only linear combinations of Raman intensities, can be fast but require careful optimization to deliver high performance. Here, we develop a neural network model to identify optimal parameters for a compressive sensing scheme that reduces measurement time by 2 orders of magnitude. In a data set containing Raman spectra of three different cell types, it achieves up to 90% classification accuracy using only five linear combinations of Raman intensities. Our method thus unlocks the power of Raman spectroscopy for the characterization of cell products.

Mountaintop Removal Coal Mining Contaminates Snowpack across a Broad Region.

Mountaintop removal coal mining is a source of downstream pollution. Here, we show that mountaintop removal coal mining also pollutes ecosystems downwind. We sampled regional snowpack near the end of winter along a transect of sites located 3-60 km downwind of coal mining in the Elk River valley of British Columbia, Canada. Vast quantities of polycyclic aromatic compounds (PACs), a toxic class of organic contaminants, are emitted and transported atmospherically far from emission sources. Summed PAC (ΣPAC) snowpack concentrations ranged from 29-94,866 ng/L. Snowpack ΣPAC loads, which account for variable snowpack depth, ranged from <10 μg/m2 at sites >50 km southeast of the mines to >1000 μg/m2 at sites in the Elk River valley near mining operations, with one site >15,000 μg/m2. Outside of the Elk River valley, snowpack ΣPAC loads exhibited a clear spatial pattern decreasing away from the mines. The compositional fingerprint of this PAC pollution matches closely with Elk River valley coal. Beyond our study region, modeling results suggest a depositional footprint extending across western Canada and the northwestern United States. These findings carry important implications for receiving ecosystems and for communities located close to mountaintop removal coal mines exposed to air pollution elevated in PACs.

Establishment of chemical fingerprint and determination of main active ingredients in Centellae Herba by HPLC combined with multivariate chemometrics analysis

AbstractIn this paper, a simple and efficient high‐performance liquid chromatography method was established to analyze the chemical composition fingerprint of Centellae Herba (CHA) and determine five triterpenoid active components in CHA, namely, asiaticoside B (AB), madecassoside, asiaticoside, madecasic acid, and asiaticoic acid. The separation of the compounds was carried out on an XD‐C18 column (250 mm × 4.6 mm, 5 µm), the wavelength of the ultraviolet detector was set to 205 nm, and the mobile phase was composed of acetonitrile −0.05% phosphoric acid, 2 mmol/L β‐cyclodextrin aqueous solution, and gradient elution at the flow rate of 1.0 mL/min. A general chromatographic fingerprint consisting of 20 characteristic peaks of 18 batches of CHA samples was established, and the samples were classified and evaluated by similarity analysis, hierarchical cluster analysis, and principal component analysis combined with multivariate econometric analysis. In quantitative analysis, all calibration curves showed good linear regression in the test range (r &gt; 0.999), the average recovery was 96.12%–104.63%, and the relative standard deviations of repeatability and stability were less than 2.00%. The results show that the method is accurate and effective and can be used for the comprehensive quality control of CHA.

Integrated multi-proxy source-to-sink analysis of Late Barremian (Lower Cretaceous) clastic systems in the Essaouira-Agadir Basin

This study investigates the provenance of the continental and marine Late Barremian clastics of the Bouzergoun Formation, exposed in the Essaouira-Agadir Basin (EAB). Thin section petrography, Scanning Electron Micrography, heavy minerals analysis, and detrital zircon dating were conducted and integrated with a large dataset of published Low-Temperature Thermochronology (LTT) studies to reconstruct the associated source-to-sink system(s). The results constrain the source and size of the system, and composition of deposited clastics, and investigate the mechanism for delivery of coarse clastics into the offshore domain, a key target for hydrocarbon exploration.The homogeneity of rock composition fingerprints throughout the basin indicates a common provenance for both the northern and southern studied transects. Hinterland analysis based on LTT data identifies the Western Meseta and Massif Ancien de Marrakech (MAM) regions as the only possible source candidates exhuming during the Late Barremian, confirmed by detrital zircon geochronology. Heavy mineral populations reveal partly recycled sediment including a probable igneous source. Rock fragment populations comprise limestones, sandstones, and volcanic composition, which correlate with lithologies of the MAM.The integration of all data suggests a best-fit model for the Late Barremian of a source-to-sink system of moderate size (200–300 km long), dominantly sourced from the MAM (western High Atlas). This provided a sand-rich mix of sediment resulting from the erosion of exhuming Triassic continental basins, with associated clays from the weathering of basalts and Triassic/Jurassic mudstones.Late Barremian eustatic sea level fall, together with regional uplift in the hinterland, is interpreted to have resulted in a forced regression that allowed the system to prograde towards the slope margin, offering enhanced potential for sand delivery into the deep offshore domain. Seismic imaging offshore provides tentative interpretation of synchronous high reflectivity deepwater channels located in structural lows controlled by diapiric salt movement.The Mesetian domain was likely undergoing denudation at the same time and shedding clastic-rich sediments to the northern part of the EAB, beyond the studied region. Sediment supply from the MAM may be mixed with the Mesetian sands to the northern part of the EAB and tentatively in the offshore Essaouira.

Classification of Algerian olive oils: Physicochemical properties, polyphenols and fatty acid composition combined with machine learning models

The regulation of olive cultivar and geographical origin is a requirement for the global extra virgin olive oil market, due to its significant impact on consumer choice. Our work involves obtaining a promising marker parameter for cultivar and geographical origin that can be used to verify declared labels. The effects of these factors on the physicochemical parameters and composition of monovarietal extra virgin olive oil (MEVOO) from Algeria were studied. Thirteen olive fruit varieties were analyzed using different physicochemical methods, including phenolic and fatty acid composition. Five classification techniques, random forests (RForest), gradient boosted trees (GBoost), Naïve Bayes (NBayes), logistic regression (LRegression) and decision tree (DTree), were applied and their results were compared. The best validation accuracy of 91.7 % was achieved with DT classification through a feature selection procedure using a genetic algorithm (GA). These results demonstrate the effective use of machine learning techniques to rapidly classify different Algerian varieties based on their compositional fingerprints.

Tropical Red Macroalgae Cultivation with a Focus on Compositional Analysis.

To create carbon efficient sources of bioenergy feedstocks and feedstuff for aquaculture and terrestrial livestock, it is critical to develop and commercialize the most efficient seaweed cultivation approach with a sustainable nutrient input supply. Here, we present data for a novel, onshore tropical macroalgae cultivation system, based on influent deep seawater as the nutrient and carbon sources. Two red algal species were selected, Agardhiella subulata and Halymenia hawaiiana, as the basis for growth optimization. Highest productivity in small-scale cultivation was demonstrated with A. subulata in the 10% deep seawater (64.7 µg N L-1) treatment, growing at up to 26% specific growth rate day-1 with highest yields observed at 247.5 g m-2 day-1 fresh weight. The highest yields for H. hawaiiana were measured with the addition of 10% deep seawater up to 8.8% specific growth rate day-1 and yields at 63.3 g fresh weight m-2 day-1 equivalent. Biomass should be culled weekly or biweekly to avoid density limitations, which likely contributed to a decrease in SGR over time. With a measured 30-40% carbon content of the ash-free dry weight (20-30% of the dry weight) biomass, this translates to an almost 1:1 CO2 capture to biomass ratio. The compositional fingerprint of the high carbohydrate content of both Agardhiella and Halymenia makes for an attractive feedstock for downstream biorefinery applications. By focusing on scaling and optimizing seaweed farming technologies for large-scale onshore farms, the opportunities for yield potential, adaptability to cultivation conditions, and meeting global sustainability goals through novel, carbon-negative biomass sources such as seaweed can be realized.

Quantifying the contributions of natural and anthropogenic dust sources in Shanxi Province, northern China

Dust storms have direct or indirect impacts on climate change and human health. Identifying and quantifying natural/anthropogenic dust sources can facilitate effective prevention and control of dust events. Based on surface real-time PM10 monitoring data, satellite remote sensing and the HYSPLIT model, this study determined the specific timing, coverage and sources of dust events in Shanxi Province, Northern China. Thus, a composite fingerprinting technique was established to quantify potential dust sources and dust contributions of single dust events. The dust oxidation model was validated, indicating that the composite fingerprinting technique was well suited to the study region. The results show that natural dust sources (67%) contributed more to the study region than anthropogenic dust sources. They were mainly from the northwest and north of the study region. Particularly, the contributions of Taiyuan (TY) and Linfen (LF) accounted for the largest (82%) and smallest (55%) proportions, respectively, both exceeding 50%. Anthropogenic dust sources contributed 33%, mainly from the east and south of the study region. The contribution of anthropogenic dust sources increased in the study region from north to south. In terms of potential dust sources, the Tengger Desert and Badain Jaran Desert (TDBD) contributed the most (26%), followed by the Otindag Sandy Land (OL) (22%). The Taklimakan Desert (TD) contributed the least (2%). The Middle Farmland region of the Hexi Corridor (HMF) in the west (15%) had the largest proportion of anthropogenic dust sources. Differences in the regional contribution of potential dust sources mainly resulted from winter winds, surface drought severity and particle size. At an insignificant distance from the study region, the contribution of potential dust sources was larger in the west than in the east and increased from south to north overall. These methods and findings can contribute to improving the ecological environment in Northern China.

Multiuser Smartphone-Based Localization by Composite Fingerprint Descriptors in Large Indoor Environments

Multiuser Smartphone-Based Localization by Composite Fingerprint Descriptors in Large Indoor Environments

High chemodiversity in the structural and enantiomeric composition of volatiles emitted by Kermes oak populations in Southern France

Investigating the intraspecific variability of volatiles produced by vegetation is of fundamental importance in the understanding of their ecological roles and in correctly assessing their fluxes from vegetation covers. We characterized foliar emissions and CO2/H2O-gas exchanges from 80 seed-grown Kermes oak (Quercus coccifera L.) saplings originating from 4 populations located on a northeast–southwest transect in Southern France. Emissions of a large range of volatiles including chiral isomers were determined under environmentally controlled conditions by online and offline gas chromatography. All saplings emitted principally α-, β-pinene, sabinene, myrcene, eucalyptol, and limonene plus traces of other monoterpenes (MTs), sesquiterpenes, and isoprene. The enantiomers of α- and β-pinene were highly correlated with a predominance of the (+)-forms in the emissions. On average, the total isoprenoid emission rate was 772 ± 398 ng m−2 s−1. The compositional fingerprint varied in a discontinuous manner among individuals unrelated to the emission quantity and little influenced by season and leaf age. Cluster analyses revealed 4 main chemotypes plus 2 subtypes, which could be explained by a combination of 5 putative MTs synthases producing predominantly myrcene, limonene, eucalyptol, (+)-pinenes, and sabinene plus (−)-pinenes, respectively. The frequency of chemotypes, the average fraction of single volatiles and the ratios of pinene enantiomers were significantly different among populations without clear geographic or climatic cline. However, plants of one chemotype, which was most abundant in the population of the driest site, expressed an increased photosynthetic water use efficiency. Overall, the results revealed a marked ubiquitous chemical polymorphism in Kermes oak populations with similarities to that observed in other MT producing oak species, especially with its closely related and sympatric congener Holm oak.

Antiulcer activity and mechanism of action of the hydroethanolic extract of leaves of Terminalia argentea Mart. In different in vivo and in vitro experimental models

Ethnopharmacological relevanceTerminalia argentea Mart. (Combretaceae) is a deciduous tree commonly found in Brazil, Bolivia, and Paraguay. It occurs in all regions of Brazil and is widespread in the Amazon, Cerrado, Pantanal, Atlantic Rain Forest, and Caatinga Biomes. In the traditional medicine of Brazil, people widely use tea or decoction of its leaf materials for treating gastritis, ulcers, wound healing, and inflammation. Aim of the studyThe current study aims to evaluate the gastroprotective and ulcer-healing activities of the hydroethanolic extract of T. argentea leaves (HETa) and investigate the underlying mechanisms of action through in vivo and in vitro experiments. MethodsWe extracted the leaves of T. argentea with a 70% hydroethanolic solution (HETa) and performed phytochemical analysis using high-performance liquid chromatography (HPLC) and electrospray ionization mass spectrometry (ESI-MSn). We researched the antiulcer activity using in vivo and in vitro experiments, administering three doses (2, 10, and 50 mg/kg) and different concentrations of 1, 5, and 20 μg/mL, respectively. We verified the acute antiulcer activity using chemical models (acidified ethanol (EtOH/HCl) and indomethacin (IND)) and physiological models (water-immersion stress (WRS)). To induce chronic ulcers, used acetic acid and treated the animals for seven days. To investigate the mechanism of action, conducted assays of antioxidant activity, measured the dosage of inflammatory cytokines, quantified mucus, treated with inhibitors (IND, L-NAME, glibenclamide, and yohimbine), performed histopathological analysis, and measured gastric acid secretion. Furthermore, we performed in vitro experiments on murine macrophage cell lines (RAW 264-7 cells) to quantify nitrite/nitrate and cytokine production and on V79-4 cells to verify cell proliferation/migration. ResultsWe conducted HPLC and ESI-MSn analyses to obtain a fingerprint of the chemical composition of the HETa, revealing the presence of phenolics (caffeoyl ellagic acid), flavonoids (rutin, quercetin xyloside, quercetin rhamnoside, quercetin glucoside, quercetin galloyl xyloside, quercetin), and tannins (terminalin), respectively. The three doses of HETa reduced acute and chronic ulcers in different models. The mechanism of action involves increasing mucus production and angiogenesis, and it partially involves prostaglandins, nitric oxide, K+ATP channels, and α2-adrenergic receptors. HETa also exhibited antioxidant potential, reducing myeloperoxidase (MPO) activity, and increasing glutathione (GSH) levels. Moreover, it demonstrated anti-inflammatory action by reducing nitrite/nitrate levels and pro-inflammatory cytokine concentrations in vivo, and it increased in vitro proliferation/migration of fibroblasts. ConclusionsThe study shows that HETa presents a potent preventive and curative antiulcer effect in different ulcer models, supporting the popular use of homemade preparations of T. argentea leaves. The preventive and gastric healing ulcer activity of HETa involves multiple targets, including increasing the gastric mucus barrier, antioxidant defenses, and anti-inflammatory effects on gastric mucosa repair. Phytochemical analysis identified the presence of phenolic compounds, flavonoids, and tannins in HETa, and the antiulcer activity may be attributable to the combined effect of these constituents.

Identification of Sedimentary Environments through Dynamic Image Analysis of the Particle Morphology of Beach Sediments on the East and West Coasts of Hainan Island in South China

Particle morphology is an important feature of sediments that reflects their transport history and depositional environment. In this study, we used dynamic image analysis (DIA) to measure the size and shape of beach sediments on the east and west coasts of Hainan Island in South China Sea. DIA is a fast and accurate method that can capture and analyze a large number of sediment particles in real-time. We extracted morphological descriptors of each particle, such as equivalent diameter, sphericity, aspect ratio and symmetry, and their distributions based on volume and number. We performed multivariate analysis on the particle morphological data, including alpha diversity, statistical analysis and fingerprint techniques. We found that the Shannon index, calculated by the number distribution of sediment particle morphology, can effectively discriminate between the two sites, reflecting different sediment sources, transport processes and depositional conditions. We also established a composite fingerprint based on seven morphological parameters and diversity indices, which can accurately distinguish between aeolian and hydraulic sedimentary environments. Our study demonstrates the potential application of DIA in identifying sedimentary environments and establishing sediment fingerprints. This can help us understand the sediment transport processes and depositional mechanisms in coastal areas.

Scheelite composition fingerprints pulsed flow of magmatic fluid in the Fujiashan W skarn deposit, eastern China

Abstract Scheelite (CaWO4) is an economically important W mineral in skarns that form when magmatic fluids exsolved from a granitic intrusion react with carbonate wall rocks. In the Fujiashan W skarn deposit, scheelite formed during four stages of the hydrothermal skarn development. We present cathodoluminescence (CL) images and in situ trace element and Sr-O isotope data of scheelite from these four stages, i.e., scheelite in prograde and retrograde skarn, quartz-sulfide veins, and late calcite replacements. Scheelite from prograde skarn and quartz sulfide veins are homogeneous and show oscillatory zoning textures in CL images, whereas scheelite from retrograde skarn and late carbonate stages display dissolution-reprecipitation and patchy textures. The brightness of CL textures decreases with a higher substitution of Mo. Molybdenum-rich scheelite (up to 2.1 wt%) is characterized by relatively high contents of Nb and Ta (up to 156 and 0.9 ppm, respectively), positive Eu anomalies, high-δ18O values (5.2 to 5.9‰), and relatively low-87Sr/86Sr values (0.70661 to 0.70727), and has grown in a system with a continuous supply of magmatic fluid. Molybdenum-poor scheelite (0.2 wt%) has low contents of Nb and Ta, negative Eu anomalies, low-δ18O values (4.2 to 4.3‰), and relatively high-87Sr/86Sr ratios (0.70748 to 0.70804). This type of scheelite formed in a system with a restricted flow of magmatic fluid during scheelite precipitation became increasingly depleted in elements that substitute into scheelite. The continued reaction of the magmatic fluid with the wall rocks and the precipitation of minerals from the fluid resulted in a systematic change of the δ18O and 87Sr/86Sr ratios. Chemical and isotopic variations in scheelite may reflect the pulsed flow of a magmatic fluid and do not require the involvement of different fluids or contrasting redox conditions.

Using geochemical elements to discriminate sediment sources in a typical karst watershed

Knowledge of temporal variations in sediment sources is necessary to identify the principal sources of sediment for effective implementation of soil conservation measures and to improve the calibration and validation of process-based soil erosion models. Quantitative information on sediment provenance is often limited in karst regions because of their complex surfaces and underground three-dimensional erosion systems. Peak-cluster depressions are typical landforms in karst areas and can well intercept most sediment from hillsides such as dams or reservoirs. Thus, peak-cluster depressions are suitable areas for sediment source identification. The objective of this study was to quantify the contribution of sediment sources in a typical karst watershed and to identify temporal variations in sediment sources in the watershed in the past 60 years. We collected 194 soil samples from three sediment profiles in a karst depression and 58 source samples from cropland, fissure soil, and forestland. We used a composite fingerprinting method based on 45 geochemical properties and an IsoSource multivariate mixed model in a typical karst watershed. The results indicate that cropland was the principal sediment source (89.2 %) in the last 60 years, followed by fissure soil (9.6 %) and forestland (1.2 %). Importantly, compared with the period from 1949 to 1999, the contribution of sediment from fissure soil reached a maximum value of approximately 20 % from 1999 to 2015. This result implies that the “Grain for Green” program, which was implemented in 1999, clearly reduced the amount of soil erosion from cropland. Therefore, the program may greatly affect sediment deposition in karst depressions. Using metal ratios as fingerprint factors, the IsoSource mixed model can be effectively used to study the source of sediments in karst watersheds quantitatively. This study can aid the existing understanding of soil erosion processes and contributes to the sustainable development of agro-ecology in karst watersheds.

The Role of Paddy Fields in the Sediment of a Small Agricultural Catchment in the Three Gorges Reservoir Region by the Sediment Fingerprinting Method

Identifying sediment sources is a prerequisite for developing sediment management strategies. Erosion sediment derived from a small agriculture catchment is an important component of sediment inflow in the Three Gorges Reservoir Area. Paddy fields are one of the major land-use types in this region and can have both positive and negative effects on sediment. In this study, two different source group classification schemes were used to analyze the effect of paddy fields on the sediment in a typical small agriculture catchment in the Three Gorges Reservoir Region. A total of 32 soil source samples were collected from four kinds of land-use types (13 from dry land, 5 from orchards, 8 from paddy fields, and 6 from forest) in the Shipanqiu catchment. Moreover, the properties consisted of 41 elements and 12 element ratios were analyzed. Composite fingerprinting methodology was applied to discriminate and quantify the sediment source contributions. Additionally, element ratio was used as the fingerprint property in the fingerprinting application. The results showed that the element ratio was verified as an effective fingerprint property. Additionally, the relative sediment contributions of the potential land-use sources were 55.25% of dry land, 32.69% of orchards, and 12.06% of forest. Paddy fields played a role of sink rather than of source in this study. Accordingly, both forest and paddy fields are effective sediment management strategies. Particularly, paddy fields are a preferred choice for soil erosion control in mountainous and hilly areas. Furthermore, the proper management of paddy fields can help promote sediment retention and reduce soil erosion, which have positive effects on both the environment and agricultural productivity.

Microwave assisted free radical degradation of Schisandra polysaccharides: Optimization, identification and application

In order to establish structural-fingerprinting of polysaccharides for improvement of quality assessment, a sample preparation method based on microwave assisted free radical degradation (MFRD) of plant polysaccharides was proposed to produce oligosaccharides and small Mw polysaccharides. As a case study of Schisandra chinensis and S. sphenanthera fruit polysaccharides (SCP and SSP), the MFRD condition (i.e., 100 °C, 30 s and 80 W) was confirmed to be optimal. The potential structures of the MFRD products of SCP and SSP were further discussed by combinations of HILIC-ESI−-QTOF-MSE and HILIC-ESI−-Q-OT-IT-MS/MS. As followed, multivariable statistical analysis shows a clear separation of SCP and the SSP in PCA and OPLS-DA plots based HILIC-ESI−-QTOF-MSE data. The VIP plot unveils several key Q-markers (e.g., peaks 3, 8, 9, 10, 15, 25, 26, 28, 29 and 30) with significant differences and stable emergences. Furthermore, a low-polymerization compositional fingerprinting was successfully constructed for SCP and SSP using a high-performance anion-exchange chromatography with pulsed amperometric detection. Compared to the conventional sample preparation methods, the MFRD took only a few thousandth of the time to accomplish degradations of plant polysaccharides. It significantly improves sample preparations and is generally applicable to various polysaccharide samples.

MALDI MSI Separation of Same Donor’s Fingermarks Based on Time of Deposition—A Proof-of-Concept Study

Despite the advent of DNA profiling, fingerprints still play an important role in suspect identification. However, if single crime scene marks may be challenging to identify, overlapping fingermarks, understandably, pose an even greater challenge. In the last decade, mass spectrometry-imaging methods have provided a possible solution to the separation of fingermarks from two or more donors, based on the differential chemical composition. However, there are no studies attempting to separate overlapping marks from the same donor. This is important in relation to fingermark deposition at different times, which could be critical, for example, to ascertain legitimate access to the scene. In the work presented here, we investigate whether Matrix-Assisted Laser Desorption Ionisation Mass Spectrometry Imaging can separate the same donor's fingermarks deposited at different times based on intra-donor fingermark composition variability. Additionally, the hypothesis that the different times of deposition could be also determined was investigated in the view of linking the suspect at the scene at different times; the dating window of MALDI MSI within the selected molecular range was explored. Results show that it is possible to separate overlapping fingermarks from the same donor in most cases, even from natural marks. Fresh marks (0 days) could be separated from those of fourteen days of age, though the latter could not be distinguished from the set aged for seven days. Due to the use of only one donor, these are to be considered preliminary data, though findings are interesting enough to warrant further investigation of the capabilities and limitations of this approach using a larger cohort of donors.

Differentiating individuals through the chemical composition of their fingermarks

Fingermark patterns are one of the oldest means of biometric identification. During this last decade, the molecules that constitute the fingermark residue have gained interest among the forensic research community to gain additional intelligence regarding its donor profile including its gender, age, lifestyle or even its pathological state. In this work, the molecular composition of fingermarks have been studied to monitor the variability between donors and to explore its capacity to differentiate individuals using supervised multi-class classification models. Over one year, fingermarks from thirteen donors have been analysed by Matrix-Assisted Laser Desorption/Ionisation Mass Spectrometry Imaging (n = 716) and mined by different machine learning approaches. We demonstrate the potential of the fingermark chemical composition to help differentiating individuals with an accuracy between 80% and 96% depending on the period of sample collection for each donor and size of the pool of donors. It would be premature at this stage to transpose the results of this research to real cases, however the conclusions of this study can provide a better understanding of the variations of the chemical composition of the fingermark residue in between individuals over long periods and help clarifying the notion of donorship.

Assembly process and source tracking of microbial communities in sediments of Dongting Lake

Sediment source tracing can accurately provide a theoretical basis for controlling soil erosion effectively, by identifying the most serious types of land use. Traditional sediment tracing methods are based on physical, chemical, biological, and composite fingerprinting, which have not included microbes. As high-throughput sequencing becomes more prevalent, microorganisms can provide more information than what we think. Thus, whether the microorganism can also be used as a special fingerprint factor for sediment source identification during soil erosion, we have tested it by using microbial source tracking tool FEAST to quantify the microbe contribution from five types of eroded land (including dryland, urban, paddy field, forest and grassland) to the depositional areas (Niubitan) in the Yuanjiang basin. The source microbial community in the erosive area was heterogeneous, and assembly process analysis further demonstrated that the source tracking results could reach higher accuracy. The results of FEAST showed that dryland (35.50%), urban (17.21%), paddy field (8.14%), and forest (1.07%) were the major contributors to Niubitan. Our results follow the general soil erosion rules and prove its validity. Taken together, a new perspective is provided by these results for tracing sediment sources in erosion-sedimentary systems.