Search Results (20,493)

In the formerly glaciated terrains in the northern hemisphere and countries such as Finland, till is the most common sediment covering the bedrock. Specifically, indicator or heavy mineral studies utilising till as a vector for mineral deposits undercover have been successful. The pyrite trace-element composition from in situ mineral analyses has been shown to be an effective discriminator between different mineral deposit types, and this has led to research using heavy mineral pyrite in till to identify potential mineral deposits in a given area. However, pyrite is easily oxidised in till beds, and thus, alternative methods should be considered. Goethite pseudomorphs are more commonly found in the till sediments as remnants after pyrite oxidation. This study evaluates trace element compositions of goethitised pyrite recovered in the till beds from central Lapland in northern Finland. Intra-grain trace-elemental variations gathered using laser-ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) between the intact pyrite core and oxidised rim demonstrated complex dynamics and variations between different trace-element values. For example, Cu, V and Mn exhibited elevated trace-element values in the goethite rim compared to the pyrite core. However, elemental ratios such as Ni/As and Co/Ni remain stable between the pyrite core and oxidised rim. Therefore, these ratios have the potential to be used as a discriminating tool between the pyrite core and oxidised rim. In addition, nanoscale variabilities using focused ion beam (FIB) and transmission electron microscopy (TEM) were utilised to inspect possible nano inclusions within the studied heavy mineral grain. The FIB and TEM studies revealed a nanocrystalline pyrite nodule observation within the goethite rim. Full article

In recent decades, there have been individual cases of damage to the revetments of the German North Sea estuaries due to clogging by precipitated ochre products. This process is defined as ochre clogging and has been extensively explained in the literature. The primary aim of the investigations was to better understand the clogging process under in situ conditions and the causative environmental conditions surrounding the filters. Extensive in situ investigations were therefore carried out. It was found that a permeability reduction in geotextile filters can be strongly accelerated by ochre clogging, which appears to be a biogeochemical process. This describes a combined action of the chemical precipitation of iron and manganese, precipitation by microorganisms, and physical clogging. A further aim of this study was to establish limit values for the decisive ochre clogging parameters, which could be used to quantify the susceptibility to ochre clogging. It was shown that the determination of the iron and manganese content of the groundwater, as well as the redox capacity of the groundwater, is sufficient to assess the tendency for ochre clogging. To minimise the negative impact on filter performance, recommendations for an adapted filter design have been developed as a guide for planners. Full article

The micro-arc oxidation (MAO) technique was used to grow in situ oxidation coating on the surface of R60705 zirconium alloy in Na₂SiO₃, Na₂EDTA, and NaOH electrolytes. The thickness, surface morphology, cross-section morphology, wear resistance, composition, and structure of the micro-arc oxidation coating were analyzed by an eddy current thickness measuring instrument, XPS, XRD, scanning electron microscopy, energy spectrometer, and wear testing machine. The corrosion resistance of the coating was characterized by a polarization curve and electrochemical impedance spectroscopy (EIS). The results show that, with the increase in frequency, the single-pulse discharge energy decreases continuously, and the coating thickness shows a decreasing trend, from the highest value of 152 μm at 400 Hz to the lowest value of 87.5 μm at 1000 Hz. The discharge pore size on the surface of the coating gradually decreases, and the wear resistance and corrosion resistance of the coating first increase and then decrease. The corrosion resistance is the best when the frequency is 400 Hz. At this time, the corrosion potential is −0.215 V, and the corrosion current density is 2.546 × 10⁻⁸ A·cm⁻². The micro-arc oxidation coating of zirconium alloy is mainly composed of monoclinic zirconia (m-ZrO₂) and tetragonal zirconia (t-ZrO₂), in which the content of monoclinic zirconia is significantly more than that of tetragonal zirconia. Full article

Additively manufactured implants, surgical guides, and medical devices that would have direct contact with the human body require predictable behaviour when stress is applied during their standard operation. Products built with Fused Filament Fabrication (FFF) possess orthotropic characteristics, thus, it is necessary to determine the properties that can be achieved in the XY- and Z-directions of printing. A concentration of 10 wt% of hydroxyapatite (HA) in polyetherketoneketone (PEKK) matrix was selected as the most promising biomaterial supporting cell attachment for medical applications and was characterized with an Ultimate Tensile Strength (UTS) of 78.3 MPa and 43.9 MPa in the XY- and Z-directions of 3D printing, respectively. The effect of the filler on the crystallization kinetics, which is a key parameter for the selection of semicrystalline materials suitable for 3D printing, was explained. This work clearly shows that only in situ crystallization provides the ability to build parts with a more thermodynamically stable primary form of crystallites. Full article

The current research examined the impact of different concentrations of oat beta-glucan (OG) on the in vitro digestibility of fava bean starch (FS). Our pasting analysis demonstrated that OG effectively decreased the viscosity and regrowth of FS, suppressing its in situ regrowth while enhancing the in vitro pasting temperature. Moreover, OG markedly diminished amylose leaching and minimized the particle size of the pasted starch. Rheological and textural evaluations demonstrated that OG markedly diminished the viscoelasticity of the starch and softened the gel strength of the composite system. Structural analysis revealed that hydrogen bonding is the primary interaction in the FS-OG system, indicating that OG interacts with amylose through hydrogen bonding, thereby delaying starch pasting and enhancing the gelatinization characteristics of FS gels. Notably, the incorporation of OG resulted in a reduction in the levels of rapidly digestible starch (RDS) and slowly digestible starch (SDS) in FS, accompanied by a notable increase in resistant starch (RS) content, from 21.30% to 31.82%. This study offers crucial insights for the application of OG in starch-based functional foods. Full article

Hybrid nanocomposites based on poly(3,6-dianiline-2,5-dichloro-1,4-benzoquinone) (PDACB) in salt form and graphene oxide (GO) have been obtained for the first time, and the significant influence of the preparation method on the composition and structure of nanocomposites and their functional properties has been demonstrated. Nanocomposites were prepared in three ways: via ultrasonic mixing of PDACB and GO; via in situ oxidative polymerization of 3,6-dianiline-2,5-dichloro-1,4-benzoquinone (DACB) in the presence of GO; and by heating a suspension of previously prepared PDACB and GO in DMF with the removal of the solvent. The results of the study of the composition, chemical structure, morphology, thermal stability and electrical properties of nanocomposites obtained via various methods are presented. Nanocomposites obtained by mixing the components in an ultrasonic field demonstrated strong intermolecular interactions between PDACB and GO both due to the formation of hydrogen bonds and π-stacking, as well as through electrostatic interactions. Under oxidative polymerization of DACB in the presence of GO, the latter participated in the oxidative process, being partially reduced. At the same time, a PDACB polymer film was formed on the surface of the GO. Prolonged heating for 4 h at 85 °C of a suspension of PDACB and GO in DMF led to the dedoping of PDACB with the transition of the polymer to the base non-conductive form and the reduction of GO. Regardless of the preparation method, all nanocomposites showed an increase in thermal stability compared to PDACB. All nanocomposites were characterized by a hopping mechanism of conductivity. Direct current (dc) conductivity σ_dc values varied within two orders of magnitude depending on the preparation conditions. Full article

For deep underground coal mining ecosystems, research on microbial communities and geochemical characteristics of sediments in different functional zones is lacking, resulting in the knowledge of zone-level mine water pollution prevention and control being narrow. In this study, we surveyed the geochemical distinctions and microbial communities of five typical functional zones in a representative North China coalfield, Xinjulong coal mine. The data indicated that the geochemical compounds and microbial communities of sediments showed distinguishing features in each zone. The microbial community richness and diversity were ranked as follows: surface water > rock roadways > sumps > coal roadways ≥ goafs. Canonical Correlation Analysis (CCA), Spearman correlation and co-occurrence network analysis demonstrated that microbial communities were sensitive and closely related to hydrochemical processes. The microbial community distribution in the underground mine was closely related not only to nutrient elements (i.e., C, S, P and N), but also to redox-sensitive substances (i.e., Fe and As). When it comes to mine water pollution prevention and control, the central zones are goafs. With the increase in goaf closure time, total nitrogen (TN), total organic carbon (TOC) and total sulfur (TS) decreased, but As, Fe and total phosphorus (TP) gradually increased, and the characteristic pollutant SO₄²⁻ concentration in water samples decreased. Additionally, the sulfate-reducing bacteria (SRB) had relatively higher proportions in goafs, suggesting goafs were able to purify themselves. In practical engineering, in situ nitrogen injection technology used to expel oxygen and create an anaerobic environment can be implemented to enhance SRB reducing sulfate in goafs. Meanwhile, because coal mine pollution discharge generally only discharges mine water and leaves sediment underground, the pollutants can be transferred to the sediment by strengthening the relevant reactions including the heavy metal solidification and stabilization function of bacteria. Full article

Preserving local autochthonous domestic animal populations and the products derived from them is a crucial aspect of managing human utilization of the biosphere. This management approach aims to ensure sustainable benefits for both present and future generations. The diversity of autochthonous domestic animal populations plays a vital role in the functionality and sustainability of the food production system. It encompasses both productive and non-productive aspects, contributing significantly to the overall health, nutrition, and food security of the landscape by providing a wide range of animal-derived food resources. Based on the data contained in the Draft Program of Rural Development, a significant presence of more than 44 autochthonous and local breeds of domestic animals has been noted in Serbia. In order to enable the sustainable preservation of local domestic animals, the competent Ministry of Agriculture of the Republic of Serbia has, through a number of projects, implemented models for the preservation of local breeds on farms (in situ), as well as provided technical assistance to small farms that keep animal collections. It also helps the local population to procure animals, conducts product quality research, and provides opportunities to integrate conservation programs through tourism. Given that molecular characterization is a key factor for the preservation of autochthonous breeds, in the Republic of Serbia, DNA markers are used for identification and to investigate the belonging to a specific breeds or strain. All the mentioned activities led to an immediate increase in the number of animals, which is especially true for the autochthonous breeds of cattle (Busha), sheep (Sjenicka, Svrljiska, and Vlach-vitohorn) and pigs (Mangalitsa, Moravka, and Resavka) that are discussed in this paper. In addition to the significant measures undertaken to preserve animal genetic resources (AnGR), it is necessary to continue to work primarily on ex situ conservation in order to prevent the loss of their gene pools. However, regardless of the evident effort that has been made to preserve autochthonous genetic resources in Serbia, we believe that there is still a lot of room for further improvement. This primarily refers to advanced technologies that have not been applied so far, mostly related to the identification of genomic regions associated with economic traits, resistance to diseases, and adaptability to emerging climate changes. In this way, the production capacity and functional characteristics of autochthonous species and breeds of domestic animals in Serbia will be improved. Full article

Bursaphelenchus mucronatus is the sibling species of B. xylophilus, which causes pine wilt disease. Sex pheromone-mediated mating behavior underlies the development of B. xylophilus populations. The study of the molecular mechanism of sex pheromone receptor genes is vital for the control of B. xylophilus. The pivotal role of the 5-HT receptor ser-1 in Caenorhabditis elegans’s mating has been demonstrated, but there is little known in B. mucronatus and B. xylophilus. In our study, the molecular features and biological functions of Bmu-ser-1 are explored. qPCR results showed that Bmu-ser-1 was expressed at all ages, especially at J2 and J4, with significantly high expression. Notably, the expression levels in males were significantly higher than that in females. The results of in situ hybridization suggest that the Bmu-ser-1 gene was expressed at the site of the digestive system during the embryonic stage, the whole body during the J2 stage, and mainly at the end of the germinal primordium during the J3 stage, as well as centrally in the vulva of females and in the gonads and tail of males during the J4 and adult stages. The RNAi results indicate a significant decrease in hatchability and stagnation at the J1 stage after interference. Treated J2 had reduced motility and stunted growth. Males after interference showed mismatch and females showed spawning difficulties. Sexual arousal experiments further validated Bmu-ser-1 as a receptor gene for males receiving female sex pheromones. Collectively, our findings strongly suggest that the Bmu-ser-1 gene has a classical role, the control of nematode growth; and a novel role involved in mating. The study on the molecular mechanisms of growth and reproduction in B. mucronatus could provide a reference for understanding the population expansion and disease epidemics of B. xylophilus. Full article

Putatively, tooth agenesis was attributed to the initiation failure of tooth germs, though little is known about the histological and molecular alterations. To address if constitutively active FGF signaling is associated with tooth agenesis, we activated Fgf8 in dental mesenchyme with Osr-cre knock-in allele in mice (Osr2-cre^KI; Rosa26R-Fgf8) and found incisor agenesis and molar microdontia. The cell survival assay showed tremendous apoptosis in both the Osr2-cre^KI; Rosa26R-Fgf8 incisor epithelium and mesenchyme, which initiated incisor regression from cap stage. In situ hybridization displayed vanished Shh transcription, and immunostaining exhibited reduced Runx2 expression and enlarged mesenchymal Lef1 domain in Osr2-cre^KI; Rosa26R-Fgf8 incisors, both of which were suggested to enhance apoptosis. In contrast, Osr2-cre^KI; Rosa26R-Fgf8 molar germs displayed mildly suppressed Shh transcription, and the increased expression of Ectodin, Runx2 and Lef1. Although mildly smaller than WT controls prenatally, the Osr2-cre^KI; Rosa26R-Fgf8 molar germs produced a miniature tooth with impaired mineralization after a 6-week sub-renal culture. Intriguingly, the implanted Osr2-cre^KI; Rosa26R-Fgf8 molar germs exhibited delayed odontoblast differentiation and accelerated ameloblast maturation. Collectively, the ectopically activated Fgf8 in dental mesenchyme caused incisor agenesis by triggering incisor regression and postnatal molar microdontia. Our findings reported tooth agenesis resulting from the regression from the early bell stage and implicated a correlation between tooth agenesis and microdontia. Full article

In response to the evolving landscape of maritime operations, new technologies are on the horizon as mixed reality (MR), which shall enhance navigation safety and efficiency during remote assistance as, e.g., in the remote pilotage use case. However, up to now, it is uncertain if this technology can provide benefits in terms of usability and situational awareness (SA) compared with screen-based visualizations, which are established in maritime navigation. Thus, this paper initially tests and assesses novel approaches to pilotage in the congested maritime environment, which integrates augmented reality (AR) for ship captains and virtual reality (VR) and desktop applications for pilots. The tested prototype employs AR glasses, notably the Hololens 2, to superimpose the Automatic Identification System (AIS) data directly into the captain’s field of view, while pilots on land receive identical information alongside live 360-degree video feeds from cameras installed on the ship. Additional minimum functionalities include waypoint setting, bearing indicators, and voice communication. The efficiency and usability of these technologies are evaluated through in situ tests conducted with experienced pilots on a real ship using the System Usability Scale, the Situational Awareness Rating Technique, as well as Simulator Sickness Questionnaires during the assessment. This includes a first indicative comparison of VR and desktop applications for the given use case. Full article

Background: Efforts on a global scale for combating malaria have achieved substantial progress over the past twenty years. Two Central American nations have accomplished their goal of eliminating malaria: El Salvador and Belize. Honduras has decreased the incidence of malaria and now reports fewer than 4000 malaria cases annually, aspiring to reach elimination by 2030. To accomplish this goal, it is essential to assess the existing strategies employed for malaria control and to address the task of incorporating novel intervention strategies to identify asymptomatic reservoirs. Methods: A survey for detecting asymptomatic cases was carried out in the community of Kaukira, in Gracias a Dios, Honduras, focusing on malaria transmission during 2023. Asymptomatic community members were recruited as participants, malaria screening was performed through a rapid diagnostic test in situ, and a blood sample was collected on filter paper. Highly sensitive molecular assays based on photo-induced electron transfer PCR (PET-PCR) were performed to detect the two species of Plasmodium circulating in Honduras: Plasmodium vivax and Plasmodium falciparum. In addition, the identification of the parasite species was verified by amplifying three genetic markers (Pvmsp3α, Pvmsp3ß, and Pfmsp1). Results: A total of 138 participants were recruited, mostly adult women. All individuals tested negative on the rapid diagnostic test. Positive results for malaria were detected by PET-PCR in 17 samples (12.3%). Most samples (12 out of 17) were amplified with a Ct value between 37 and 42, indicating very low parasitemias. Out of the 17 samples, 16 of them also showed amplification in the species assays. There were nine cases of P. falciparum infections and seven cases of P. vivax infections that were further confirmed by nested PCR (nPCR) of Pvmsp3 and Pfmsp1. Parasitemias ranged from 100 p/μL to less than 0.25 p/μL. One sample showed mixed infection. Conclusions: The existence of asymptomatic malaria reservoirs in Honduras can contribute to disease transmission and pose a challenge that may hinder elimination efforts, requiring public health authorities to modify surveillance strategies to identify the disease and treat this population accordingly. Full article

Permeability characterized by permeability coefficient is one of the important engineering properties of clay, and its permeation mechanism depends on the permeation process of water in clay. To clarify the characteristics and influencing factors of the anisotropy of stress in red clay, indoor variable head permeability tests were conducted to obtain the permeability coefficients of undisturbed red clay in vertical and horizontal directions under different overlying loads. The research results indicate that under the same overburden load, the vertical permeability coefficient (k_V) is greater than the horizontal permeability coefficient (k_H), and on semi-logarithmic coordinates, both permeability coefficients exhibit a linear negative growth relationship with the overburden load. Moreover, with a gradual increase in the overburden load, the permeability coefficient ratio kV/kH shows a decreasing trend. When the overburden load does not exceed 150 kPa, the ratio of permeability coefficients (k_V/k_H) shows a linear decreasing trend, and when the overburden load exceeds 150 kPa, the rate of decrease gradually slows and eventually stabilizes. It is also found that the void ratio (e) is linearly related to lgk_V and lgk_H, and based on this, a prediction model for the anisotropy of stress in undisturbed red clay based on permeability coefficients is established. Under increasing osmotic pressure, the permeability coefficients in both directions exhibit linear growth. Essentially, it is the osmotic pressure that alters the stress pathways of red clay, and the smaller the overburden load, the greater the effect of osmotic pressure. With the increase in the overburden load, the anisotropy of stress gradually weakens. Full article

Ground source heat pump (GSHP) systems depend on the capacity for heat transfer between the system and the ground, and it is good practice to carry out an in situ thermal response test (TRT) to determine the undisturbed ground temperature, the thermal conductivity of the ground, and the thermal resistance of the borehole. Conventionally, a TRT is undertaken in a replica borehole heat exchanger (BHE); however, alternative methods have been developed that can provide continuous depth-resolved temperature recordings. The enhanced TRT (ETRT) uses a hybrid cable system which incorporates a resistance heating wire to provide a linear heat source and a fibre optic cable to measure the temperature along the length of the borehole. In this paper, a case study is presented in which a TRT and ETRT were carried out in the same BHE to evaluate its thermal response and estimate the thermal characteristics of the ground. After a brief introduction of both methods and their interpretation, a comparison between them is presented regarding their advantages and disadvantages using the results of the performed tests, which revealed an 8% difference in the soil thermal conductivity values, averaged over the length of the BHE. Full article

Genebanks, other than their pivotal role as diversity conservation repositories, regenerate part of their collection every year to maintain their material in optimal conditions. During regeneration cycles, morpho-physiological data are collected, contributing to the creation of large datasets that offer a valuable resource of information. In Italy, rice cultivation has been documented since the second half of the 15th century, and nowadays, Italy contributes more than 50% of the total European rice production. The ex situ collection of rice (mainly Oryza sativa L. subgroup japonica) held at the Research Center for Cereal and Industrial Crops (CREA-CI) of Vercelli is quite unique in Italy and its establishment dates back to the beginning of the 20th century. The collection is hereby presented through the analysis of 21 years of historic data, from 2001 to 2022, in 17 different locations in Northern Italy, for a total of 6592 entries, 677 genotypes analyzed and 9 phenotypic traits under investigation. An R script has been developed to analyze the dataset. The BLUEs calculation, heritability, PCA and correlation with weather data provided a comprehensive overview of the germplasm stored in the genebank. The great variability and phenotypic diversity were assessed, key aspects from the perspective of breeding programs. This work starts a re-evaluation of historic data, historic cultivars, and represents the first step toward the shift of the genebank to a bio-digital resource center. Full article