Non-affected Samples Research Articles

A Christmas gift: Signature of the 24th December 2018 eruption of Mt. Etna on the chemical composition of bulk deposition in eastern Sicily

The eruption of Mt. Etna which occurred on December 24th 2018 was characterized by strombolian activity and fire fountains, emitted by the New South-East Crater and along a fissure that propagated towards the SE. The influence of volcanic emissions on atmospheric deposition was clearly detectable at several kilometres from the source. Wet and dry (bulk) deposition samples were collected each month, through a network of eleven collectors, in the areas of Milazzo, and Priolo between June 2018 and June 2019. They were analysed for major ions and trace elements concentrations. The pH values range from 3.9 to 8.3, while the EC values range from 7 to 396 μS cm-1. An extensive neutralization of the acidity has been recognised mainly due to the suspended alkaline dust particles, which have a buffering role in rainwater. A high load of Na+ and Cl- was observed at all sites, related to the closeness of the study areas to the coast, showing a high positive correlation (R2 = 0.989) along the line of Na+/Cl- ratio in seawater. During the eruption, the volcanic plume was carried by the winds for long distance (more than 300 km) affecting the area of Priolo but not that of Milazzo, which was upwind with respect to Mt. Etna. The impact of volcanic HF was clearly recognised in the samples collected after the eruption. Volcanic SO2 and HCl had a lower impact due to the overwhelming input of anthropogenic sulfate and marine chloride. On the contrary, the signature of the Mt. Etna eruption can be well recognised in the high concentrations of certain trace elements in the samples collected immediately after the eruption. The strongest contrast between affected and non-affected samples was recognised in Al, Cd, and especially in the volatile elements Tl and Te, which are typically enriched in volcanic emissions. The results showed that volcanic eruptions might have a relevant effect on the atmospheric chemistry and on the composition of rainwater up to distances of 80 km from the emission vents.

Heavy metals in iron ore tailings and floodplain soils affected by the Samarco dam collapse in Brazil

In November 2015, the Fundão Dam collapsed releasing about 35 million m−3 of iron ore tailings into the environment, which covered approximately 15 km2 of floodplain soils. Four years later, there is still great concern and controversy regarding contamination by heavy metals in the affected areas. Thus, the present study sought to evaluate the heavy metal contents and its distribution in tailings and non-affected soils. Tailings samples were collected in the stretch between Bento Rodrigues and the Candonga hydroelectric plant, in addition to a sample inside the Fundão Dam. Non-affected soils and river sediments from the same region were also collected as a control group. The heavy metal contents in the tailings were lower than in non-affected samples from the same area, discarding the hypothesis of contamination by the tailings mud. The non-affected samples presented high levels of As, Ba, Co, Cr, Cu, Ni and Zn, with at least one sample exceeding the quality reference values (QRV's) established for Minas Gerais state, which indicated a scenario of pre-disaster contamination for the Doce River watershed. Most of the elements (As, Cr, Cu, Ni, V and Zn) were extracted in the residual fraction of the BCR sequential extraction, presenting low risk of release in nature. The health risk assessment for As estimated that all the non-affected soils and sediments from Gualaxo do Norte, Carmo and Doce rivers have carcinogenic risk higher than the acceptable value for children. From our results, it is more likely to conclude that the deposited tailings are not a time-bomb for heavy metals contamination in the region.

Changing of mechanical characteristics of Co-based amorphous alloy and Fe-based nano-crystalline alloy in the hydrogenous medium under the influence of impulse electric current

Experimentally established the preliminary influence of hydrogen-containing medium (NACE) in cobalt-based amorphous alloys reduces the temperature of the onset of ductility during annealing. The structure of the surface changes forming in the holding of samples in the NACE medium either separate NaCl crystals or branched crystalline structures on the surface. A layer of oxide appears on the nanocrystalline alloy is preventing in heat exchange between the sample and environment. The passing of the impulse electric current j = 108 – 109 A/m2 results increases mechanical stress releases comparing to non-affected samples by the hydrogen-containing medium because of the temperature increase. The amorphous structure proves to be more resistant under simultaneous influence with the impulse electric current to the effect of the hydrogen medium NACE compare to the nanocrystalline one.

Enzymatic efficacy of some types of Aspergillus fungi isolated from some manuscripts and its effect on some of the physical and chemical properties of the manuscripts

The study has been conducted in the laboratory of Imam Hussein Center (peace be upon him) for the restoration and conservation of manuscripts and the care of researchers at the Imam Hussein Holy Shrine. 150 fungal isolates of Aspergillus spp. have been taken from manuscripts. Aspergillus, Aspergillus flavus, Aspergillus nidulans, Candidus,Apergillus oryzae, Apergillus niger were diagnosed. The enzymatic tests were performed to determine which species has the ability to produce analyzer of protein,cellulose, fat and starch enzymes on solid culture media of specific inspection.The results showed that Aspergillus fungi were differentiated in its production of the studied enzymes. A. nigar gave positive result for all studied enzymes with varying level of efficacy. The highest enzyme activity of this species was amylase, lipase and cellulase. However, A.oryza recorded the highest efficacy of cellulase and amylase and medium efficacy with protease. A. candidus was producing high efficacy to protease, lipase and cellulase enzymes and gave a negative test with the amylase enzyme. A.flavus was the higher efficacy with protease, lipase, cellulase enzymes and medium efficacy with amylase, while A. nidulan was recorded as the highest efficacy with protease, lipase, and cellulase enzymes and medium efficacy with amylase enzyme.The effect of growth of these fungi on the physical properties of the elongation strength, tension force and color change of paper was studied. The results showed that the effect of fungi on the manuscripts through the exposure of the damaged sample to the dark color compared to the standard sample (unaffected). The results demonstrated that the lowest values in term of tensile strength and elongation for the affected sample compared to the non-affected sample, as well as the study of their effect on the chemical properties using X-ray diffraction analysis to determine the degree of crystallization of cellulose. The results showed an increase in the crystallization of cellulose. This means a change in the chemical and mechanical properties of cellulose. In addition, the infrared spectrum was used to determine changes in the functional groups of paper observing which revealed occurring a slight decrease in the OH group as a result of the loss of water molecules from cellulose. Also, we noticed an increase in C = O absorption due to cellulose oxidation processes.

Medium‐term effect of early life weather shock on non‐verbal intelligence of Sidr affected children

The present study intends to investigate the medium-term effect of early life weather shock on non-verbal intelligence of SIDR affected children. The hypothesis was, the nonverbal IQ of SIDR affected children would be lower than the non-verbal IQ of SIDR non-affected children. For this purpose, 60 students of grade 4 - 5 were selected as respondents. Among them half of the respondents were from SIDR affected area and remaining were from non-affected area. In order to measure non-verbal intelligence, Test of Non-verbal Intelligence-2 (TONI-2) was administered which was developed by Brown et al. (1990). Independent-sample t-test was employed to compare the non-verbal intelligence of the participants in SIDR affected and SIDR non-affected conditions. The result shown that there is a significant difference on non-verbal intelligence between affected and non-affected samples and the nonverbal intelligence (IQ) of SIDR affected children is significantly lower than the non-verbal intelligence (IQ) of non-affected participants.
 Dhaka Univ. J. Biol. Sci. 28(1): 61-69, 2019 (January)

Analysis of soft magnetic materials by electron backscatter diffraction as a powerful tool

The current work demonstrates that electron backscatter diffraction (EBSD) is a powerful and versatile characterization technique for investigating soft magnetic materials. The properties of soft magnets, e.g., magnetic losses strongly depend on the materials chemical composition and microstructure, including grain size and shape, texture, degree of plastic deformation and elastic strain. In electrical sheet stacks for e-motor applications, the quality of the machined edges/surfaces of each individual sheet is of special interest. Using EBSD, the influence of the punching process on the microstructure at the cutting edge is quantitatively assessed by evaluating the crystallographic misorientation distribution of the deformed grains. Using an industrial punching process, the maximum affected deformation depth is determined to be 200 - 300 μm. In the case of laser cutting, the affected deformation depth is determined to be approximately zero. Reliability and detection limits of the developed EBSD approach are evaluated on non-affected sample regions and model samples containing different indentation test bodies. A second application case is the investigation of the recrystallization process during the annealing step of soft magnetic composites (SMC) toroids produced by powder metallurgy as a function of compaction pressure, annealing parameters and powder particle size. With increasing pressure and temperature, the recrystallized area fraction (e.g., grains with crystallographic misorientations < 3°) increases from 71 % (200 MPa, 800°C) to 90% (800 MPa, 800°C). Recrystallization of the compacted powder material starts at the particle boundaries or areas with existing plastic deformation. The progress of recrystallization is visualized as a function of time and of different particle to grain size distributions. Here, large particles with coarse internal grain structures show a favorable recrystallization behavior which results in large bulk permeability of up to 600 – 700 and lower amount of residual misorientations (>3°).

Integrative genomic analyses for identification and prioritization of long non-coding RNAs associated with autism.

Genetic studies have identified many risk loci for autism spectrum disorder (ASD) although causal factors in the majority of cases are still unknown. Currently, known ASD risk genes are all protein-coding genes; however, the vast majority of transcripts in humans are non-coding RNAs (ncRNAs) which do not encode proteins. Recently, long non-coding RNAs (lncRNAs) were shown to be highly expressed in the human brain and crucial for normal brain development. We have constructed a computational pipeline for the integration of various genomic datasets to identify lncRNAs associated with ASD. This pipeline utilizes differential gene expression patterns in affected tissues in conjunction with gene co-expression networks in tissue-matched non-affected samples. We analyzed RNA-seq data from the cortical brain tissues from ASD cases and controls to identify lncRNAs differentially expressed in ASD. We derived a gene co-expression network from an independent human brain developmental transcriptome and detected a convergence of the differentially expressed lncRNAs and known ASD risk genes into specific co-expression modules. Co-expression network analysis facilitates the discovery of associations between previously uncharacterized lncRNAs with known ASD risk genes, affected molecular pathways and at-risk developmental time points. In addition, we show that some of these lncRNAs have a high degree of overlap with major CNVs detected in ASD genetic studies. By utilizing this integrative approach comprised of differential expression analysis in affected tissues and connectivity metrics from a developmental co-expression network, we have prioritized a set of candidate ASD-associated lncRNAs. The identification of lncRNAs as novel ASD susceptibility genes could help explain the genetic pathogenesis of ASD.

'Candidatus Phytoplasma brasiliense' (16SrXV-A Subgroup) Associated with Cauliflower Displaying Stunt Symptoms in Brazil.

Cauliflower stunt, caused by a phytoplasma of the group 16SrIII-J, was reported in the beginning of 2012 and has occurred with high incidences of infected plants (up to 90%) in crops located in the state of São Paulo in the southeast region of Brazil (3). Diseased plants exhibit general stunting, malformation of inflorescence, reddening leaves, and vessel necrosis (3). Further investigations with plants displaying identical symptoms collected in Nova Bassano, state of Rio Grande do Sul, Brazilian south region, have revealed the presence of a phytoplasma distinct from 16SrIII-J subgroup. Four symptomatic plus four asymptomatic samples were assayed from a field, and the presence of phytoplasma was evidenced by nested PCR assays performed with primers P1/Tint followed by R16F2n/16R2 in three affected plants, which amplified genomic fragments of 1.2 kb from the 16S rRNA gene. No amplification occurred in non-affected samples. Nested PCR products analyzed by conventional RFLP (2) using the enzymes AluI, RsaI, KpnI, HpaII, MseI, HhaI, MboI, and BstUI pointed to the presence of a phytoplasma belonging to group 16SrXV-A in all three phytoplasma-positive samples. Virtual RFLP analysis based on restriction patterns, derived from in silico digestion with 17 endonucleases (4), confirmed the previous results obtained from those samples by conventional RFLP. The 16S rDNA sequences of this phytoplasma identified in cauliflower (GenBank Accession No. JN818845) shared 99% sequence similarity with the reference phytoplasma for subgroup 16SrXV-A (Hibiscus witches'-broom phytoplasma, AF147708), designated 'Candidatus Phytoplasma brasiliense.' Analysis of putative restriction sites showed excellent identity between the phytoplasma studied here and the reference phytoplasma. In addition, the arrangement of branches of a phylogenetic tree constructed with phytoplasmas representing diverse 16Sr groups and subgroups supported that the phytoplasma found in cauliflower is closed related to the representative of the subgroup 16SrXV-A. Association of distinct phytoplasmas with the same kind of disease is not rare and the present pathosystem constitutes a new example. Members of this subgroup have been described almost exclusively in Brazil and previously reported in Sida sp., periwinkle, and hibiscus (1). In some European countries, as well as in the United States and Canada, phytoplasmas belonging to group 16SrI has been associated with this type of disease, which has been reported for various species of the genus Brassica, as published in previous works (3). However, a representative of the group 16SrVI was described in infected plants in Iran (3). Although the 16SrIII-J phytoplasma is currently the most important agent of cauliflower stunt in Brazil, and members of 16SrI are prevalent in other countries, this study revealed that a 16Sr XV-A phytoplasma may be also associated with this important disease of brassicas. Besides, the findings here reported expand the natural host range, including cauliflower as new host for phytoplasmas affiliated with 16SrXV-A.

A novel real-time ultrasonic method for prion protein detection using plasminogen as a capture molecule

BackgroundHigh resolution ultrasonography (HR-US) can monitor the molecular changes and biochemical interactions between proteins in real-time. The aim of this study was to use HR-US to characterize the real-time interactions between plasminogen coated beads and PrPSc and to determine if this approach could be applied to the identification of animals affected by prion diseases. Plasminogen, immobilized to beads, was used as a capturing tool for PrPSc in brain homogenates from scrapie affected sheep and the binding reaction was monitored in real-time in an ultrasonic cell.ResultsChanges in the ultrasonic parameters suggested that three processes occurred during the incubation: binding, protein-protein network formation and precipitation and that these processes occurred in a concentration dependent manner. Conversely, when homogenates from normal sheep were similarly examined, no evidence for the occurrence of these processes was found indicating the specificity of the interaction between the plasminogen coated beads and PrPSc.ConclusionThese results indicate firstly, that the plasminogen coated beads binded selectively to PrPSc and secondly, that a HR-US system can discriminate between scrapie affected and non-affected samples and thus has potential as a tool for the rapid diagnosis for prion diseases. This approach has the significant advantage of not requiring a proteinase K pre-digestion step, which is routinely used in current PrPSc detection assays.

Eddy currents to control steel decarburising

The work presented in the present paper aims at evaluating the opportunity of the eddy current method to characterise the decarburising extent which can occur during usual heat treatments of steel like austenising. The present work is based on previous studies highlighting the ability of eddy current to detect superficial defects such as cracks, pores or the possibility to corroborate its signal intensity with the mechanical microhardness modifications generated by carburising of steel. That is why eddy current is used here to systematically compare non-affected sample with the decarburised ones at different levels of decarburising. Among the techniques available to characterise the extent of decarburising, i.e. optical observations and microhardness profile, the eddy current technique provides a non-destructive method which is often required from an industrial control point of view. The results obtained show a strong correlation between the eddy current signal and the decarburised depth of the samples. As a consequence, they open realistic perspectives to characterise decarburising industrially.

IDENTIFICATION OF PETROLEUM RESIDUE SOURCES AFTER A FIRE AND OIL SPILL

ABSTRACT The evaluation of the environmental impacts resulting from an oil spill and fire at the West Hackberry Strategic Petroleum Reserve Complex was particularly challenging. The fire and spill resulted in two distinctive types of chemical releases into the environment. The spill released a large quantity of Arabian light crude oil into an area that had been exposed to Louisiana sweet crude oil during 40 years of production. The fire produced significant quantities of pyrogenic polycyclic aromatic hydrocarbons that were dispersed over a large area by wind. New methods were developed to identify samples, and consequently the areas, that were affected by these releases. Samples of sediment affected by the oil spill were distinguished from nonaffected samples by comparing the ratios of the alkyl phenanthrenes to the alkyl dibenzothiophenes (C1, C2, and C3) in a gas chromatography–mass spectrometry analysis of the extractable hydrocarbons. These ratios effectively identified affected sediment even when the samples had been exposed to the environment for more than a year. Contamination from the pyrogenic products of the fire was identified by the elevated quantities of fluoranthene and pyrene in affected samples. Foliage, soil, and sediment samples were collected quarterly for the year following the incident and were analyzed by the combined gas chromatography-mass spectrometry method. Impact from the fire was detected in foliage and soil samples collected several miles downwind from the incident.