High Background Levels Research Articles

The influence of natural geochemical provinces on the drinking water quality and the public health risk formation

The high content of chemical elements in the sources of drinking water in addition to anthropogenic contamination may be due to the presence of the source in a particular geochemical provinces, creating the initially high background levels of chemicals of concern in water. It was found that among 14 geochemical provinces of Perm region in 4 there was the excess of the maximum allowable concentrations in water sources: the manganese to 2.3 MAC and strontium to 17.0 MAC. It is shown that, despite the use of modern methods of water treatment used in the economic activity and for the purpose of drinking water, in drinking water after treatment manganese, fluorine, strontium, beryllium and Nickel exceeding to 20.0 MPC, substance characteristic water sources within the boundaries of the geochemical provinces, are recorded. The event production control does not always include a program of sampling on the specific geochemical provinces of the substance, such as boron, bromine, barium, etc. In the course of the assessment of health risk from consumption of drinking water from sources located within the boundaries of geochemical provinces obtained that the coefficients of the danger (HQ) exceeded the acceptable level to 2.2 times for a number of substances, and the hazard index (HI) of health disorders exceeded the permissible level up to 2.5 times. The total contribution of the typical geochemical provinces of substances has reached 100,0 % for some organs and target systems.

Single-Photon Detectors Modeling and Selection Criteria for High-Background LiDAR

Vision systems capable of acquiring both two-dimensional and three-dimensional information through Light Detection And Ranging are assuming ever-increasing importance, being this market driven by the push from automotive companies to develop systems to be integrated in self-driving vehicles. Among others, candidate sensors for these systems are avalanche photodiodes, single-photon avalanche diodes, and silicon photomultipliers. Avalanche Photodiodes provide a good robustness to high background light at the cost of requiring an analog readout, instead Single-Photon Avalanche Diodes offer the possibility to implement digital readout and single-photon sensitivity, but are prone to saturation at extremely high background levels. We compare these three single- and multi-photon detector topologies, operated either in linear or digital regime, aiming at identifying the best suited detector to achieve the highest performance in Light Detection And Ranging applications at the lowest optical power active illumination and in presence of intense background (e.g. 100 klux). We present Matlab modelling and simulations and their experimental validation. Eventually, we propose a nomogram (referred to 100 m target distance) for identifying the most suited sensor topology across different operating areas and constraints, in order to achieve at least 70% success ratio.

Coding closed and open quantum systems in MATLAB: applications in quantum optics and condensed matter

We develop a package of numerical simulations implemented in MATLAB to solve complex many-body quantum systems. We focus on widely used examples that include the calculation of the magnetization dynamics for the closed and open Ising model, dynamical quantum phase transition in cavity QED arrays, Markovian dynamics for interacting two-level systems, and the non-Markovian dynamics of the pure-dephasing spin-boson model. These examples will be useful for undergraduate and graduate students with a medium or high-level background in MATLAB, and also for researchers interested in numerical studies applied to quantum optics and condensed matter systems.

Investigating the expression level of NF-KB and HIF1A genes among the inhabitants of two different background radiation areas in Ramsar, Iran

This study investigated the fluctuation of NF-KB and HIF-1a gene expression between inhabitants of a high-level background radiation area (HBRA) and a normal-level background radiation area (NBRA) of Ramsar, Iran. Sixty participants with the mean age of 48 ± 15 years were selected and divided into two groups. The group receiving a dose of ≤1.5 mGy/year (NBRA) was considered the control group and the target group (HBRA) received a dose of >1.5 mGy/year. These two groups were from neighbor regions to minimize socioeconomic differences between the participants. Blood samples were collected from each group and NF-KB and HIF-1a expression levels were compared using quantitative real-time PCR (qPCR) based on the stem loop method. The effects of residency duration in the respective areas and gender on the expression of NF-KB and HIF-1a was also examined. The HIF-1a expression level was statistically lower in the HLBRA region (P < 0.0002), while NF-KB expression was upregulated (P < 0.0001). Although the under-expression of HIF-1a in response to dose rate was significant in females (P < 0.0004), it was not different in males (P = 0.74), indicating a significant difference between sexes (P = 0.0047). The upregulation of NF-KB expression related to dose level was also significant for the female group (P < 0.0001), whereas it was not for the male group (P = 0.72). Notably and as expected, there was a significant relation between longer residency in the HBRA and HIF-1A under-expression (P < 0.026), while there was no effect of increasing residency time for NF-KB over-expression level (P = 0.29). The dwellers of the HBRA those noted that despite receiving an elevated radiation level were seemingly good in general health, showed some alterations in their molecular mechanisms, specifically HIF-1a and NF-KB expression levels. It is not clear if this is indicative of a beneficial adaptive response and more research is recommended.

Mapping large-scale diffuse γ-ray emission in the 10−100 TeV band with Cherenkov telescopes

Context. Measurement of diffuse γ-ray emission from the Milky Way with Imaging Atmospheric Cherenkov Telescopes (IACT) is difficult because of the high level of charged cosmic ray background and the small field of view. Aims. We show that such a measurement is nevertheless possible in the energy band 10−100 TeV. Methods. The minimal charged particle background for IACTs is achieved by selecting the events to be used for the analyses of the cosmic ray electrons. Tight cuts on the event quality in these event selections allow us to obtain a sufficiently low background level to allow measurement of the diffuse Galactic γ-ray flux above 10 TeV. We calculated the sensitivities of different types of IACT arrays for the Galactic diffuse emission measurements and compared them with the diffuse γ-ray flux from different parts of the sky measured by the Fermi Large Area Telescope below 3 TeV and with the astrophysical neutrino signal measured by IceCube telescope. Results. We show that deep exposure of existing IACT systems is sufficient for detection of the diffuse flux from all the Galactic Plane up to Galactic latitude |b| ∼ 5°. The Medium Size Telescope array of the CTA will be able to detect the diffuse flux up 30° Galactic latitude. Its sensitivity will be sufficient for detection of the γ-ray counterpart of the Galactic component of the IceCube astrophysical neutrino signal above 10 TeV. We also propose that a dedicated IACT system composed of small but wide-field-of-view telescopes could be used to map the 10−100 TeV diffuse γ-ray emission from across the whole sky. Conclusions. Detection and detailed study of diffuse Galactic γ-ray emission in the previously unexplored 10−100 TeV energy range is possible with the IACT technique. This is important for identification of the Galactic component of the astrophysical neutrino signal and for understanding the propagation of cosmic rays in the interstellar medium.

Detecting moving targets in active sonar echograph of harbor environment using high-order time lacunarity.

This paper presents a feature for detecting potential targets from high level littoral clutters in active sonar echographs. Based on lacunarity, which describes the image texture statistics, an extension to the time domain is made in order to measure the dynamic behavior of target echoes and background clutters. Moreover, as high-order moments have been shown to well characterize the non-Rayleigh tails of littoral clutter, high-order computation is incorporated in the proposed high-order time lacunarity (HOT-Lac). The potential of HOT-Lac is demonstrated using a series of active sonar echographs with diverse cooperative targets detected in real-world harbor environments in the South China Sea. Specifically, it is shown how HOT-Lac can effectively distinguish different moving small targets from high-level background clutter, and how this ability can be exploited to highlight an invasion target in harbor security.

Abstract No. 422 Biomarker discovery using established and primary hepatocellular carcinoma cell lines

Hepatocellular carcinoma (HCC) is the fastest rising cause of cancer related death. The limited role of biopsy in diagnosis and treatment monitoring emphasizes the importance of developing biomarkers for incurable disease. The identification of biomarkers from serum in patients with HCC is limited by the high levels of background resulting from albumin. The purpose of this study was to overcome this limitation in order to identify novel biomarkers using unbiased proteomic profiling of HCC secreted proteins derived from established and primary HCC cell lines. Following 48-hour incubations, media was collected from 5 HCC established and primary HCC cell lines as well as 5 non-HCC cell lines including normal hepatocytes, fibroblasts and a colorectal cancer line. Unbiased profiling of secreted proteins was performed using liquid chromatography-mass spectrometry (LC-MS). The removal of serum from culture media overcame the high background signal that results from albumin and has limited proteomic profiling of secreted proteins in patient serum. Unbiased LC-MS profiling of secreted HCC proteins by the assayed cell lines enabled the identification of 36 proteins that were present at detectable levels in HCC cell lines but at limited or undetectable levels in non-HCC cell lines (Table 1). While several of these proteins were previously identified as candidate biomarkers of HCC based on a literature search, others have not been reported. Unbiased proteomic profiling of secreted proteins derived from serum-free culture media of established and primary HCC cell lines enabled the discovery of secreted proteins that represent promising biomarker candidates.Tabled 1Top 36 Hits in HCC cell lines vs non-HCC & non-liver cell linesAccessionDescriptionP01011-1Alpha-l-antichymotrypsinP02771Alpha-fetoproteinP10451-1OsteopontinP10451-5Isoform 5 of OsteopontinP09237MatrilysinP00995Serine protease inhibitor Kazal-type 1P56470galectin-4P05026Sodium/potassium-transporting ATPase subunit beta-1P05089Arginase-1P08294Extracellular superoxide dismutase [Cu-Zn]P78509ReelinP60022Beta-defensin 1P36268Inactive glutathione hydrolase 2Q8NFZ8Cell adhesion molecule 4095671-1N-acetylserotonin O-methyltransferase-like proteinP41240tyrosine-protein kinase CSKQ9H479fructosamine-3-kinaseP52926-1high mobility group protein HMGI-CQ9BX67Junctional adhesion molecule CP18846Cyclic AMP-dependent transcription factor ATF-1P51654-1Glypican-3P38571lysosomal acid lipase/cholesteryl ester hydrolase060256-1Phosphoribosyl pyrophosphate synthase-associated protein 2Q9C0C9(E3-independent) E2 ubiquitin-conjugating enzymeP02790HemopexinQ9Y6N7Roundabout homolog 1Q9HAT2sialate O-acetylesteraseQ969Q060S ribosomal protein L36a-likeQ58WW2DDB1- and CUL4-associated factor 6O94868F-BAR and double SH3 domains protein 2P09467Fructose-l,6-bisphosphatase 1P07902Galactose-l-phosphate uridylyltransferaseQ8N392-1Rho GTPase-activating protein 18Q96PK6-1RNA-binding protein 14Q5R3I4tetratricopeptide repeat protein 38P98155-1very low-density lipoprotein receptor Open table in a new tab

Application of Superresolution Radial Fluctuation (SRRF) Imaging to Measurement of Single-Molecule DNA Hybridization Kinetics

Superresolution radial fluctuations (SRRF) is a novel algorithm based superresolution imaging technique that incorporates radial intensity gradients and temporal intensity fluctuations to calculate and project SRRF images with resolution up to 2x below the diffraction limit in real time. SRRF, has been used for imaging sub-diffraction intracellular structures and for performing time-resolved superresolution measurements of live cell dynamics. However, no application to single-molecule localization and tracking techniques has been shown. Here, we characterize the capabilities of the SRRF algorithm on measuring DNA hybridization kinetics from a DNA capture surface via single-molecule localization and tracking. We find that SRRF data has some obvious advantages such as a substantial increase in the signal-to-background ratio of single-molecule data. This is a side effect of the image radiality transform which yields low radiality values for regions which contain randomized intensity values on the distance scales of the radiality calculation. This is particularly usefully when measuring hybridization kinetics with slow on rates which necessitate higher solution phase concentrations and resulting in higher background levels. We also find that with sparse data such as these, molecule localization can be performed by calculation of the 1st moment centroids of the SRRF point spread functions (PSF) which can deliver spatial resolution similar to non-linear fitting of the optical PSF but with much faster computational times. Finally, we explore the ability for SRRF to resolve individual molecules in high DNA surface density conditions which result in many overlapping optical PSFs. We find that measuring single-molecule data following the SRRF radiality transform allows for resolving much higher densities of molecules than diffraction limited images thus allowing for faster collection of statistically significant population data.

Mechanisms underlying the promotion of osteosarcoma cell proliferation and invasion by lncRNA PBB12.

PBB12, a long noncoding RNA (lncRNA), has not been reported to be involved in the progression of osteosarcoma to date. According to our research data, it was found that osteosarcoma patients with a high PBB12 level frequently showed increased metastasis. Mechanistic research demonstrated that PBB12 can competitively bind to hsa‑miR‑204‑5p by acting as a microRNA sponge. Furthermore, PBB12 intervenes in the Kruppel‑like factor 4 (KLF4)/hsa‑miR‑204‑5p/activating transcription factor 2 (ATF2) pathway and affects the proliferation and invasion of osteosarcoma cells. High PBB12 expression was founld to lead to the loss of function of the cancer suppressors KLF4 and hsa‑miR‑204‑5p; these effects are the intrinsic reason why osteosarcoma patients with high levels of PBB12 often develop tumor metastases. Invitro functional experimental data showed that in the osteosarcoma cell lines MG63 and SAOS‑2, PBB12 silencing and overexpression significantly increases or reversed the inhibitory effect of KLF4 on the proliferation and invasion of tumor cells, respectively. The involvement of the interaction between PBB12 and the KLF4/hsa‑miR‑204‑5p/ATF2 pathway in osteosarcoma progression was reported for the first time, and these data provide important theoretical support for gene therapy targeting KLF4 and hsa‑miR‑204‑5p. The great significance of this study is that a high or low genetic background level of PBB12 in osteosarcoma patients may serve as an important marker for screening patients for a high risk of tumor metastasis. Furthermore, for osteosarcoma patients with high PBB12 expression, the primary task for all accurate personalized clinical treatment programs may be the determination of how to effectively knock down PBB12 in tumor bodies.

Conformal tracking for all-silicon trackers at future electron–positron colliders

Conformal tracking is an innovative and comprehensive pattern recognition technique using a cellular automaton-based track finding performed in a conformally-mapped space. It is particularly well-suited for light-weight silicon systems with high position resolution, such as the next generation of tracking detectors designed for future electron–positron colliders. The algorithm has been developed and validated with simulated data of the CLICdet tracker. It has demonstrated not only excellent performance in terms of tracking efficiency, fake rate and track parameters resolution but also robustness against the high beam-induced background levels. Thanks to its geometry-agnostic nature and its modularity, the algorithm is very flexible and can easily be adapted to other detector designs and experimental environments at future e+e− colliders.

Effects of industrial effluents containing moderate levels of antibiotic mixtures on the abundance of antibiotic resistance genes and bacterial community composition in exposed creek sediments

Environmental discharges of very high (mg/L) antibiotic levels from pharmaceutical production contributed to the selection, spread and persistence of antibiotic resistance. However, the effects of less antibiotic-polluted effluents (μg/L) from drug-formulation on exposed aquatic microbial communities are still scarce. Here we analyzed formulation effluents and sediments from the receiving creek collected at the discharge site (DW0), upstream (UP) and 3000 m downstream of discharge (DW3000) during winter and summer season. Chemical analyses indicated the largest amounts of trimethoprim (up to 5.08 mg/kg) and azithromycin (up to 0.39 mg/kg) at DW0, but sulfonamides accumulated at DW3000 (total up to 1.17 mg/kg). Quantitative PCR revealed significantly increased relative abundance of various antibiotic resistance genes (ARGs) against β-lactams, macrolides, sulfonamides, trimethoprim and tetracyclines in sediments from DW0, despite relatively high background levels of some ARGs already at UP site. However, only sulfonamide (sul2) and macrolide ARG subtypes (mphG and msrE) were still elevated at DW3000 compared to UP. Sequencing of 16S rRNA genes revealed pronounced changes in the sediment bacterial community composition from both DW sites compared to UP site, regardless of the season. Numerous taxa with increased relative abundance at DW0 decreased to background levels at DW3000, suggesting die-off or lack of transport of effluent-originating bacteria. In contrast, various taxa that were more abundant in sediments than in effluents increased in relative abundance at DW3000 but not at DW0, possibly due to selection imposed by high sulfonamide levels. Network analysis revealed strong correlation between some clinically relevant ARGs (e.g. blaGES, blaOXA, ermB, tet39, sul2) and taxa with elevated abundance at DW sites, and known to harbour opportunistic pathogens, such as Acinetobacter, Arcobacter, Aeromonas and Shewanella. Our results demonstrate the necessity for improved management of pharmaceutical and rural waste disposal for mitigating the increasing problems with antibiotic resistance.

Desialylation and Apoptosis Crosstalk to Modulate Platelet Clearance

Our understanding of cell biological processes involved in aging has advance greatly over the past decades. Platelets are small cells that circulate for 4-5 days in mice and 7-10 days in humans. And even though, platelets are anucleated cells, a growing body of evidence shows that platelet clearance is a well-regulated mechanism. We have recently demonstrated that platelets lose sialic acid as they circulate and age in blood and are rapidly cleared by the hepatic Ashwell-Morell receptor (AMR). And others have shown, in a series of studies using genetically modified mice or pharmacological inhibitors that platelets undergo apoptosis by triggering the intrinsic mitochondrial apoptotic machinery. Here, we investigate if desialylation and apoptosis are related events. First, using a newly developed state-of-the-art technique called dynamic BH3 profiling (DBP), we investigated the mitochondria readiness to undergo apoptosis on platelets derived from WT and AMR deficient (Asgr2-/-) mice. In our assay, digitonin-permeabilized platelets were exposed to activators signaling peptides (such as Bim, Bid and PUMA), and as cells undergo apoptosis due to peptide treatment, they released Cytochrome C. Our data showed that desialylated platelets derived from Asgr2-/-mice have high background levels of Cytochrome C release when compared to WT platelets in the presence of all activator peptides, indicating that desialylated platelets are highly primed to apoptosis. We also tested the level of dependence on pro-survival protein, by using sensitizer peptides (Bad, Hrk and MS1). We observed that desialylated platelets (Asgr2-/-platelets), and to a certain degree, WT platelets, are extremely sensitive to BCL-xL inhibition, as indicated by the extremely high response to Bad and Hrk peptides even at lower concentrations (0.1 and 1uM). Surprisingly, WT and Asgr2-/-platelets show very little response to the MS1 peptide, indicating that they are not dependent on MCL1 for survival, as otherwise suggested. Flow cytometry analysis revealed desialylated platelets from Asgr2-/-mice have a ~2-fold increase in Phosphatidylserine (PS) surface exposure when compared to WT platelets. In addition, western blot analysis showed increased expression of cleaved caspase 3 in Asgr2-/-platelets, but no changes in Bcl-xL protein expression between WT and Asgr2-/-platelets. Next, WT and Asgr2-/-mice received a single dose of the BH3 mimetic, ABT-737, which binds and inhibits pro-survivor proteins (Bcl-2, Bcl-xL and Bcl-w) inducing apoptosis in vivo. Approximately 2 hours after the injection of ABT-737, we observed a big drop on platelets counts in both WT (~42%) and Asgr2-/-(~59%) mice. Importantly, platelets from Asgr2-/-mouse were cleared more efficiently (~20%) from the circulation when compared to those in WT mice, consistent with the ~20% increment in platelet number observed in this mouse model and supporting the notion that the platelets that circulate longer in the Asgr2-/-mice are more sensitive to apoptotic events. To investigate if apoptosis could be triggering platelet desialylation, WT mice were treated with ABT-737 and 1hour later (time point before platelet count drop), platelets were collected and analyzed by flow cytometry. Interestingly, analysis of galactose exposure by RCA-I lectin showed no differences in desialylation between ABT-737 and PBS control groups. On the other hand, Phosphatidylserine (PS) exposure was significantly elevated on ABT-737 group, indicating that platelets were undergoing apoptosis without changing their sialylated status. To confirm our in vivodata, freshly isolated washed WT platelets were treated with ABT-737 to induce apoptosis or Neuraminidase (NA) to desialylated platelets. NA treatment induced platelet desialylation (increased RCA-I binding) in WT platelets, as expected, and interestingly triggered apoptosis, judge by increased PS exposure in both ABT-737 and NA treated groups. However, ABT-737 treatment wasn't able to induce desialylation as levels of RCA-I binding to platelets was the same when compared to PBS control platelets. Taken together, our data shows that desialylated platelets in circulation are prone to apoptosis. In addition, our findings strongly support the hypothesis that desialylation of platelet surface glycoproteins trigger the intrinsic apoptotic pathway in platelets in vivo. Disclosures No relevant conflicts of interest to declare.

Effects of phosphorus and nitrogen fertilization on soil arylsulfatase activity and sulfur availability of two tropical plantations in southern China

Understanding how phosphorus (P) and nitrogen (N) fertilization influence the dynamics of other nutrients [particularly sulfur (S)] is essential for improving the integrated nutrient management of tropical plantations. This study investigated how adding P and N fertilizers would affect S dynamics in the soils of two tropical forest plantations. Specifically, we tested whether the addition of P and N alters the availability of exchangeable S and microbial biomass S (MBS) and, hence, arylsulfatase activity (AS) and ratios of AS to C- and/or N-acquiring enzyme activity in the 0–5 cm soil layer were measured. The sites contained both control plots (no fertilizer application) and plots with 6-year continuous fertilizer (P and N) application. Soil exchangeable S clearly decreased, while AS activity marginally increased in P-fertilized plots. The ratios of soil AS activity to C- and/or N-acquiring enzyme activity tended to increase, possibly because the requirements of microbes for S relative to C and N were elevated, with P fertilization exacerbating shortages in S. In comparison, N fertilization did not influence exchangeable S, soil pH, and MBS. This lack of response might be attributed to continuous deposition of high levels of background N at the study sites. Soil AS activity and the ratios of soil AS activity to C- and/or N-acquiring enzyme activity tended to be lowered by N fertilization; thus, AS activity might be more sensitive to N fertilization than to soil pH. In conclusion, P fertilization must be carefully managed in tropical forest plantations to minimize its negative impact on soil S availability.

Development of a quick dot blot assay for the titering of bovine ephemeral fever virus

BackgroundBovine ephemeral fever virus (BEFV) causes fever and muscle stiffness in cattle, resulting in negative economic impact for cattle and dairy farms. During the manufacturing process of inactivated vaccine for virus control, it is important to determine the virus titer, but traditional methods such as plaque assay and TCID50 assay require days of waiting time. We sought to develop a quick dot blot assay for BEFV titering.ResultsThree different kinds of BEFV antigens were prepared to raise primary antibodies for BEFV detection in dot blot assays: 1) purified BEFV particles, 2) Escherichia coli (E. coli)-expressed BEFV G1 region, and 3) E. coli-expressed BEFV N protein. Results showed that antibodies raised against purified BEFV particles can detect BEFV particles, but it also showed a high background level from the proteins of BHK-21 cells. Antibodies raised against E.coli-expressed BEFV G1 region could not detect BEFV particles in dot blot assays. Finally, antibodies raised against E.coli-expressed BEFV N protein detected BEFV particles with a high signal-to-noise ratio in dot blot assays.ConclusionsE.coli-expressed N protein is a suitable antigen for the production of antiserum that can detect BEFV particles with a high signal-to-noise ratio. A dot blot assay kit using this antiserum can be developed as a quick and economical way for BEFV titering.

Saliency Object Detection from Video Streams using Salient-Graph Model with High-Level Background Prior

This study proposes a novel salient graph model with high-level background prior. As usual, the collected data is pre-processed and then used for segmentation analysis. Object detection is still a daunting task due to increased complexity of false positive rate. Thus, a salient graph model is constructed using high-level background prior. Initially, the contrast of an image enhanced for superpixels and used for finding the shortest path of visible region. Then, saliency map is formed by spatial analysis of those visible superpixels. In salient post-processing, the salient graph is constructed by labelling background nodes with minimized cost. Based on formed salient region, each adjacent superpixel with background nodes are used for queries. Atlast, the estimated saliency and objectness measures detects the objects with minimal constraints. The proposed framework is analyzed on SegTrack and SegTrack 2, video segmentation dataset. The results states that the proposed method achieves better results than state of the art models by improved precision, recall, F-measure and computational time.

Spatial Distribution and Pollution Assessment of As at a Small Scale in Agricultural Soils of the Karst Region

The karst landforms in Guizhou are widely distributed, and the problem of soil arsenic (As) pollution is prominent in these areas because of the high environmental background levels. In order to study the distribution characteristics of As contents in agricultural soils with high background values of As, representative As polluted regions (typical karst region, semi-karst region) in southwestern Xingyi City of Guizhou Province were selected as the research objects, and the non-karst region served as the control group. Geostatistical analyses were then combined with GIS data to study the spatial variability and pollution conditions of As in agricultural soils. Furthermore, Moran's I statistic was used to analyze the spatial autocorrelation and directional characteristics of As at a small scale in the soil. The results showed that As contents in soils from different geomorphological regions were ranked as follows:typical karst region > semi-karst region > non-karst region. The arithmetic mean value and geometric mean value of As in agricultural soils in the typical karst region were 47.9 mg·kg-1 and 43.3 mg·kg-1, respectively. Meanwhile, the arithmetic mean value and geometric mean value of As in agricultural soils in the semi-karst region were 36.8 mg·kg-1 and 30.1 mg·kg-1, respectively. The As content in agricultural soils from these two regions was significantly higher than the background values of As in Guizhou. In addition, the standard exceedance rates of As in those two regions were 98.5% and 96.7%, respectively, thus demonstrating a high degree of As accumulation. In contrast, the standard exceedance rate of As in the non-karst region was only 6.7%. Among these three afore-mentioned landform types, the results of independent sample T tests showed that there were no significant differences in the content of As between agricultural soil and (natural) soil (P>0.05). The Moran's I coefficient of the As content in agricultural soil was 0.45, and the Z value was 11.61, thus suggesting that there was a significant positive spatial autocorrelation at the small scale (P<0.05), especially in the northeast-southwest direction, and the structural variation was dominant. The As polluted agricultural soils were generally at the slight pollution and mild pollution levels, which accounted for 27.10% and 29.02% of the samples, respectively. However, some regions were at the level of moderate pollution. The non-polluted samples accounted for 41.94% of the samples.

Is Telomere Length a Biomarker of Adaptive Response in Space? Curious Findings from NASA and Residents of High Background Radiation Areas.

Telomere length and stability is a biomarker of aging, stress, and cancer. Shortening of telomeres and high level of DNA damages are known to be associated with aging. Telomere shortening normally occurs during cell division in most cells and when telomeres reach a critically short length, DNA damage signaling and cellular senescence can be triggered. The induction of an adaptive response by space radiation was first documented in 2003. Telomere length alterations are among the most fascinating observations in astronauts and residents of high background radiation areas. While study of the chronic exposure to high levels of background ionizing radiation in Kerala, India failed to show a significant influence on telomere length, limited data about the NASA astronaut Scott Kelly show that exposure to space radiation can induce telomeres to regain length. Interestingly, his telomeres shortened again only a couple of days after returning to Earth. The difference between these situations may be due to the differences in radiation dose, dose-rate, and/or type of radiation. Moreover, Scott Kelly’s spacewalks (EVA) could have significantly increased his cumulative radiation dose. It is worth noting that the spacewalks not only confer a higher dose activity but are also characterized by a different radiation spectrum than inside the space craft since the primary particles would not interact with the vehicle shell to generate secondary radiation. Generally, these differences can possibly indicate the necessity of a minimum dose/dose-rate for induction of adaptive response (the so called Window effect).

Feasibility Study of a New Cherenkov Detector for Improving Volcano Muography.

Muography is an expanding technique for internal structure investigation of large volume object, such as pyramids, volcanoes and also underground cavities. It is based on the attenuation of muon flux through the target in a way similar to the attenuation of X-ray flux through the human body for standard radiography. Muon imaging have to face with high background level, especially compared with the tiny near horizontal muon flux. In this paper the authors propose an innovative technique based on the measurement of Cherenkov radiation by Silicon photo-multipliers arrays to be integrated in a standard telescope for muography applications. Its feasibility study was accomplished by means of Geant4 simulations for the measurement of the directionality of cosmic-ray muons. This technique could be particularly useful for the suppression of background noise due to back-scattered particles whose incoming direction is likely to be wrongly reconstructed. The results obtained during the validation study of the technique principle confirm the ability to distinguish the arrival direction of muons with an efficiency higher than 98% above 1 GeV. In addition, a preliminary study on the tracking performance of the presented technique was introduced.

Dating the Anthropocene in deep-sea sediments: How much carbon is buried in the Irminger Basin?

Evaluation of biogeochemical processes in Anthropocene deep-sea sediments require accurate dating techniques. Here we show the results of an approach using high resolution low level background gamma spectrometry with two simultaneous hyper-pure germanium (HPGe) detectors. The quantitative role of the deepest zones (>3000 m depth) of the Irminger Basin (Subpolar North Atlantic Ocean) as a carbon sink during the Anthropocene is evaluated combining a chronology based in the natural radionuclide 210Pb with sedimentological analysis and elemental composition. The average sedimentation rate of the central Irminger is 1.28 ± 0.18 mm·yr−1, with a mean weighted flux to the sediment for inorganic and organic carbon of 46 ± 15 g·Cinorg·m−2·yr−1 and 8 ± 1 g·Corg·m−2·yr−1. The biogenic fraction of the mass flux is increased since the XXth century. The contribution of the deepest zones of the Irminger Basin to the Anthropocene carbon sequestration in the North Atlantic Ocean is considerable at basin-scale.

Introducing a new tool for greenhouse gas calculation tailored for cropland: rationale, operational framework and potential application

The new GHG calculator named SECTOR (Source-selective and Emission-adjusted GHG CalculaTOR for Cropland) is based on the IPCC Tier 2 approach for rice as well as other crops. The new features of SECTOR facilitate high flexibility in terms of entering newly obtained emission factors, easy data transfer from crop statistics for entering activity data and detailed specifications of GHG scenarios. A new procedure of entering frequency-based data on current water management practices was also developed. Moreover, the tool allows deviating from the 2006 IPCC Guidelines by considering field records with high background levels of N2O emissions in the overall assessment of GHG emissions.This article assesses different applications of the tool, namely as add-ons to field measurements, for GHG calculation at national/sectorial scale and within measurement, reporting and verification of development projects. SECTOR is downloadable in the form of templates that can be used to develop custom versions with varying levels of disaggregated data entries at different scales. A case study for rice production in one Vietnamese province demonstrates the potential to display GHG results in combination with GIS. SECTOR can easily be adjusted to incorporate new emission factors and calculation procedures expected in forthcoming revisions of the IPCC Guidelines.HighlightsA new GHG calculation tool was developed based on the IPCC Tier 2 approach for rice as well as other cropsFeatures of the tool facilitate high flexibility in terms of emission factors, easy data transfer from crop statistics for entering activity data and detailed specification of GHG scenariosThis article assesses different user groups and possible applications of the toolA case study for rice production in one Vietnamese province demonstrates the potential to display GHG results in combination with GIS