Proposed Threshold Values Research Articles

Temporal and spatial variations in the effect-based ecotoxicological assessment of streams

BackgroundWater bodies are affected by chemical contamination, including micropollutants, which is not fully captured by conventional chemical monitoring methods. The inclusion of integrative, effect-based in vivo and in vitro methods in standardized assessment procedures offers the possibility of bridging discrepancies between chemical and biological assessments and has already been proposed in several studies. However, there is a need to develop a comparable ecotoxicological assessment system for surface waters as for chemical and ecological status. This study aims to contribute to this discourse by investigating the temporal and spatial variation of ecotoxicological effects by assessing water grab samples of 15 different sites in central Germany over the course of 1 year using different in vitro assays.ResultsThe level of measured estrogenicity and anti-estrogenicity varied between the four measurement campaigns, while baseline toxicity, dioxin-like effects and mutagenicity showed relatively constant detectable effects over the study period. The impact of conventionally treated wastewater appeared to be one of the strongest influencing stressors, as direct comparisons of ecotoxicity upstream and downstream of wastewater treatment plant dischargers showed a significant increase for most of the conducted bioassays. Comparison of the measured estrogenicity with proposed threshold values showed effects within ecotoxicologically relevant ranges.ConclusionsBioassays record ecotoxicological effects on the basis of specific modes of action, allowing whole groups of substances to be identified as pollutants. Recording ecotoxicological status in this way is a useful complement to water assessment tools and can contribute to successful water management. Although most of the assays in this study were very consistent in detecting strong anthropogenic influences, possible temporal variations of individual assays should be taken into account when planning sampling strategies to improve the comparability of results.

Performance Analyzes of Thermodynamic Indices and Atmospheric Parameters in Thunderstorm and Non-thunderstorm Days in Istanbul, Turkey

This study aims to analyze the thunderstorm (TS) events in the megacity Istanbul by using thermodynamic indices and atmospheric stability parameters for the period of 2001–2022. It was determined that TS events did not show any trend on an annual basis, mostly (%69) occurred in the warm season (May–September), and mostly (%93) lasted for a few hours (0–3 h). The thermodynamic indices and atmospheric stability parameters used in the study are Showalter Index (SI), Lifted Index (LI), Severe Weather Threat Index (SWEAT), K-Index (KI), Totals Totals Index (TTI), Convective Available Potential Energy (CAPE), Convective Inhibition (CIN), and Bulk Richardson Number (BRN). Annual and seasonal analyzes of all indices and parameters were performed for TS and non-TS events. Significant differences were found in both average, maximum, and minimum values. The Probability of Detection (POD), False Alarm Ratio (FAR), Miss Rate (MR), Critical Success Index (CIS), Hiedke Skill Score (HSS), and True Skill Score (TSS) were used to analyze the success of the threshold values presented in the literature in detecting TS events. Then, the seasonal successes of these threshold values were tested. It was observed that the performance of the selected indices varied across seasons. The highest predictive skill was generally observed during the summer season, with the POD value ranging between 0.58 and 0.97 and the TSS value varying between 0.32 and 0.57. Conversely, the lowest predictive skill was typically observed during the winter season, where the POD value ranged from 0.00 to 0.75 and the TSS value varied between 0.00 and 0.40. The ideal threshold values were determined for indices and parameters by increasing or decreasing the existing threshold values at certain rates. Success increases of up to 15% in skill scores for the proposed threshold values.

Halobacterium yunchengense sp. nov., Natronomonas amylolytica sp. nov., Halorientalis halophila sp. nov., Halobellus salinisoli sp. nov., halophilic archaea isolated from a saline lake and inland saline soil.

Four halophilic archaeal strains YCN1T, YCN58T, LT38T, and LT62T were isolated from Yuncheng Salt Lake (Shanxi, China) and Tarim Basin (Xinjiang, China), respectively. Phylogenetic and phylogenomic analyses showed that these four strains tightly cluster with related species of Halobacterium, Natronomonas, Halorientalis, and Halobellus, respectively. The AAI, ANI, and dDDH values between these four strains and their related species of respective genera were lower than the proposed threshold values for species delineation. Strains YCN1T, YCN58T, LT38T, and LT62T could be differentiated from the current species of Halobacterium, Natronomonas, Halorientalis, and Halobellus, respectively, based on the comparison of diverse phenotypic characteristics. The polar lipid profiles of these four strains were closely similar to those of respective relatives within the genera Halobacterium, Natronomonas, Halorientalis, and Halobellus, respectively. The phenotypic, phylogenetic, and genome-based analyses indicated that strains YCN1T, YCN58T, LT38T, and LT62T represent respective novel species within the genera Halobacterium, Natronomonas, Halorentalis, and Halobellus, for which the names Halobacterium yunchengense sp. nov., Natronomonas amylolytica sp. nov., Halorientalis halophila sp. nov., and Halobellus salinisoli sp. nov. are proposed, respectively.

Microtexturing of industrial surfaces via radial ultrasonic vibration-assisted machining: An analytical model and experimental validation

The aim of this paper is to develop an analytical model to predict different texture patterns obtained with Radial Ultrasonic Vibration Assisted Machining (RUVAM) and estimate the dimensions of their characteristic features. It is also validated experimentally by performing advanced surface metrology on C45 specimens. The model is based on considering the machining of craters along radial tracks as the main texturing mechanism due to the change in the effective depth of cut provoked by the ultrasonic vibration of the insert. Mathematical formulae composing the model are then developed by considering how the machined craters in those tracks interact radially and axially, describing the final texture as the result of a multidirectional geometrical interaction. To predict how those interactions take place depending on the manufacturing parameters chosen, threshold values for the feed rate and the depth of cut are proposed. They also allow the validation of the formulae that estimate the different geometrical descriptors of craters (radial and axial heights and widths). According to the different combinations of parameters, the model succeeds in proposing diverse potential texturing scenarios. In the second part of this paper, a full factorial design is planned and applied on C45 specimens to validate the results with a RUVAM tool of 40 kHz and a 1 μm-amplitude. The plan includes three factors (insert nose radius, depth of cut and feed rate). Their levels are defined according to the threshold values for feed and depth of cut defined by the model to reproduce different textures. Results prove that the proposed threshold values allow a very good assessment of the resulting microtexturing structures on the surfaces. The measured values of widths and heights are in agreement with the values predicted by the model. With this technique, the heights of the textured surfaces span from 5 to 400 μm and widths from 45 to 720 μm, depending on the selected parameters. In the radial direction, the vibratory motion of the insert is robustly imprinted on the material, with radial heights and widths of around 2 μm and 39.6 μm, agreeing with the model. In overall, errors comparing the experimental measurements and the values predicted by the model rise up to 9%, although this error can reach 15% at some cases on radial descriptors because of their higher sensitivity to the F-filtering. A last texturing mechanism can be attributed to RUVAM related to the shaping of craters, as different oval permeters can be obtained by combining the parameters adequately. All these results lead to potential future studies related with the functional implications of all the detected textures.

Actinomycetospora lemnae sp. nov., A Novel Actinobacterium Isolated from Lemna aequinoctialis Able to Enhance Duckweed Growth.

Duckweed-associated actinobacteria are co-existing microbes that affect duckweed growth and adaptation. In this study, we aimed to report a novel actinobacterium species and explore its ability to enhance duckweed growth. Strain DW7H6T was isolated from duckweed, Lemna aequinoctialis. Phylogenetic analysis based on its 16S rRNA gene sequence revealed that the strain was most closely related to Actinomycetospora straminea IY07-55T (99.0%), Actinomycetospora chibensis TT04-21T (98.9%), Actinomycetospora lutea TT00-04T (98.8%) and Actinomycetospora callitridis CAP 335T (98.4%). Chemotaxonomic and morphological characteristics of strain DW7H6T were consistent with members of the genus Actinomycetospora, while average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) between the draft genomes of this strain and its closely related type strains were below the proposed threshold values used for species discrimination. Based on chemotaxonomic, phylogenetic, phenotypic, and genomic evidence obtained, we describe a novel Actinomycetospora species, for which the name Actinomycetospora lemnae sp. nov. is proposed. The type strain is DW7H6T (TBRC 15165T, NBRC 115294T). Additionally, the duckweed-associated actinobacterium strain DW7H6T was able to enhance duckweed growth when compared to the control, in which the number of fronds and biomass dry weight were increased by up to 1.4 and 1.3 fold, respectively. Moreover, several plant-associated gene features in the genome of strain DW7H6T potentially involved in plant-microbe interactions were identified.

Comparative study on anthropogenic impacts on soil PAHs: Accumulation and source apportionment in tourist and industrial cities in Hebei Province, China

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous organic contaminants in urban soils. The accumulation and source identifications of PAHs within a city have been frequently studied. However, impacts of urbanization development modes on PAHs accumulation patterns by taking a city as a whole have been seldom reported. Four cities with two development modes in Hebei province, Chengde and Zhangjiakou (tourist cities) and Handan and Tangshan (industrial cities), were selected. The concentrations of 16 priority PAHs in soils in the study areas were investigated. The results showed that the average concentrations of Σ16PAHs in Handan (2517 μg/kg) and Tangshan (2256 μg/kg) were more than twice of those in Chengde (696 μg/kg) and Zhangjiakou (926 μg/kg) approximately. Lines of evidence, provided by a combination of diagnostic ratios, pairwise correlation, and PMF methods, revealed that the dominant sources of PAHs in either city were industrial emission, vehicle emission, and petrogenic/biogenic process but with different proportions. Linear fittings based on Bayesian kernel machine regression analysis (BKMR) were constructed to illustrate the impact of industrialization on PAHs accumulation. The probability of excessing the 10 % (376 μg/kg) and 50 % (1138 μg/kg) of current ∑16PAHs would be higher than 90 % given the gross industrial production per unit area >5.00 × 106 and 20.5 × 106 CNY/km2, respectively. The proposed threshold values of industrialization are of significance for determining industrial structure and proportion in urban management.

The importance of inspecting the inoculum’s methane production for estimating kinetic parameters in biochemical methane potential tests

The aim of this study was to improve the quality of estimations of the first-order kinetic constant k, in Biochemical Methane Potential (BMP) tests. The results showed that existing guidelines for BMP tests are not sufficient to improve the estimation of k. The methane production of the inoculum itself exerted a major influence on the estimation of k. A flawed value in k was correlated with a high endogenous methane production. Excluding blanks that showed a distinct lag-phase of >1 day and a mean relative standard deviation >10% during the first ten days of a BMP test helped to retrieve more consistent estimates for k. For improving the repeatability in the determination of k in BMP tests, it is strongly recommended to inspect the methane production rate of the blanks. The proposed threshold values may be applied by other researchers but need further verification with different data.

Evaluation of muscle strain injury severity in active human body models

Even though significant efforts in the field of injury detection with finite element active human body models (FE AHBMs) have been made, injuries of the muscle-tendon unit (MTU) have not yet been taken into consideration. Therefore, the goal of this study was to define a muscle strain injury criterion (MSIC) to evaluate the damage sustained by the musculature during muscle driven movement scenarios. The MSIC was derived from biomechanical tests found in the literature and the proposed threshold values were substantiated through a comparison to an estimate of the ultimate tensile strength of human skeletal muscle and the forces acting on the biceps femoris long head muscle during one sprinting gait cycle. The application of the MSIC to state-of-the-art FE AHBMs was demonstrated by evaluating the strain injury severity of selected neck muscles of a full-body AHBM during two seat rotation load cases. The results of the MSIC substantiation suggest that all three injury threshold values proposed in this work fall in a plausible corridor of forces acting on the MTU. The combined results of the AHBM simulations indicate that neither of the two examined seat rotations are likely to cause strain injury to the neck muscles and that the proposed MSIC can easily be applied to current AHBMs without further modification of the model architecture or the muscle parameters. The MSIC was also used to formulate a hypothesis on the aetiology of muscle strain injuries, through which it was demonstrated that material inhomogeneities in the MTU might be the cause for strain injuries sustained during otherwise physiological movements. This work is a first step in the direction of the definition of a wholistic injury criterion for the human skeletal muscle fibre.

Rainfall Forecasting Using GPS-Derived Atmospheric Gradient and Residual for Tropical Region

In recent studies, precipitable water vapor (PWV) has caught the interest of researchers in predicting rainfall. However, rainfall depends on several other atmospheric factors that play a vital role in its initiation. With only one atmospheric parameter, the false prediction is high, especially for long-term prediction. In this article, a new method for rainfall forecasting is proposed using horizontal tropospheric gradient and atmospheric residual that are important weather features. It is observed that the gradient orientation defines the weather front for a larger region, and the gradient slope, gradient magnitude, and atmospheric residual play a crucial role in rainfall prediction. The algorithm is based on global positioning system (GPS) PWV data from stations in the tropical region. This proposed algorithm obtains average false alarm (FA) and true detection (TD) rates of 36.6% and 87%, respectively, for a prediction window of 6 h. The proposed threshold values are found to be similar for three different tropical stations that make the algorithm location independent. The comparison of this approach with several other data suggests that this algorithm is suitable in the practical scenario for a long-term rainfall prediction with a better TD rate and a minimal FA rate.

A note on some uncertainties associated with Thornthwaite's aridity index introduced by using different potential evapotranspiration methods

Potential evapotranspiration (PET) is a key parameter for climate classification and aridity assessment. The widely used UNEP (1992) classification system is based on the estimation of the aridity index AI, which requires annual average values of precipitation P and PET. For the calculation of PET the Thornthwaite's (1948) formula is, in principle, suggested. Recent studies use more advanced and accurate methods for PET estimation but apply to AI the same thresholds proposed by UNEP for aridity classification. This work deals with the uncertainties introduced by the use of different PET methods in the estimation of the aridity index AI. Specifically, the Hargreaves-Samani (HS) method and four of its modifications, three modifications of Thornthwaite's formula and the equation of Hamon, are evaluated against the widely used Thornthwaite's original method, by assessing their impact on the AI. Climatic data as monthly average values of at least 30 years of measurements from 122 stations in the Greek peninsula are used. Results show that AI is highly affected by the PET method adopted, resulting thus to changes in climatic classification of a region. Further, results imply the need for an adjustment of the threshold values that determine aridity classes according to the method each time adopted. Therefore, new threshold values for the aridity classes are developed and presented in this work. The proposed threshold values cover a range of sites that belong to semi-arid SA, sub-humid SH and humid H aridity classes of the Greek peninsula.

Optimal selection of threshold in EIT reconstructed images for estimating size of objects

It is useful to convert reconstructed images to binary form for quantitatively establishing shapes and sizes of objects. In this work, we present guidelines for selecting appropriate threshold values based on systematic numerical investigations assuming prior knowledge of conductivity contrast. Various configurations of objects immersed in a background were considered. Open source software electrical impedance diffused optical reconstruction software (EIDORS) was used for reconstructing differential EIT images for these configurations. Diametric conductivity profiles were used to identify appropriate values of threshold to obtain accurate object size over a wide range of contrast. The calculated values of threshold and the resulting effect on estimated object size were compared with the usually preferred thresholds of 1/2 (FWHM) and 1/4 (FWQM) of maximum amplitude on the basis of size accuracy. It was found that the proposed threshold offers better size accuracy with respect to change in position and size of the object over a wide range of contrasts. The proposed threshold values were found to work satisfactorily for 15 dB signal to noise ratio and 10% error in conductivity contrast.

Surrogate safety evaluation and validation with crash history for interurban midblock sections under heterogeneous traffic conditions in India

Traditionally, road safety analysis has been conducted by analysing collision records, which has a reactive approach as the analyst waits for collisions to occur. The alternate proactive approach in the form of surrogate safety measures is to study traffic conflicts which are bound to occur more frequently and thus has related them to the possible incidences of collisions. In the present study, traffic conflict indicators have been used to assess the level of safety by considering the typical midblock sections of an interurban corridor using vehicle trajectory data extracted through microscopic simulation. The surrogate safety parameters such as Time to Collision (TTC), Deceleration Rate (DR), change in velocity (Delta V) as well as conflicting vehicle Speed (Max S) have been extracted from trajectory data through the application of numerical elaboration to evaluate safety. Further, an attempt has been made to quantify the traffic conflicts occurring at the midblock of referred study. The proposed threshold values of surrogate safety parameters have been validated using the reported three years’ crash data. The approach presented in the paper has helped in the identification of midblock locations prone to road crashes and hence has served as a proactive alternative as opposed to historical crash based analysis.

Flavobacterium pokkalii sp. nov., a novel plant growth promoting native rhizobacteria isolated from pokkali rice grown in coastal saline affected agricultural regions of southern India, Kerala

Nine plant-associated bacterial strains designated as L1I52T, NRK F1, NRK F15, NRK F16, NRK F41, NRK F42, NRK F47, NRK F49, and NRK F50 originating from the roots and rhizosphere region of a coastal saline tolerant pokkali rice were taxonomically characterized in this study. Genomic fingerprinting using Enterobacterial Repetitive Intergenic Consensus (ERIC) primers discriminated the nine strains based on the DNA fingerprint patterns indicating that they were not clonal in origin. Phylogenetic analysis using 16S rRNA and other five housekeeping genes (gyrB, glyA, atpA, dnaK and murG) revealed that the novel strains constituted a single novel species within the genus Flavobacterium. In all tree construction methods, the novel strains formed a distinct phylogenetic branch, with Flavobacterium daejeonense GH1-10T, F. sufflavum BBQ-12T, and F. glycines Gm-149T as their nearest phylogenetic neighbours. However, average nucleotide identity (ANI), average amino acid identity (AAI) and digital DNA-DNA hybridization (dDDH) comparison between the draft genomes of L1I52T (representative isolate) and it’s nearest phylogenetic neighbours were well below the proposed threshold values (<95 % and <70 %) used for species discrimination. Thus, based on the phenotypic, genotypic and chemotaxonomic data obtained in this study, we describe a novel Flavobacterium species for which we propose the name Flavobacterium pokkalii sp.nov., with strain L1I52T (=MTCC 12454T=KCTC 42429T) as the type strain. In addition, L1I52T is a potential plant growth promoting rhizobacteria as they can promote pokkali rice growth and we identified several plant associated gene features in the genome of L1I52T that are potentially involved in plant microbe interactions.

Approaches to denote treatment outcome: Clinical significance and clinical global impression compared.

ObjectivesThe authors of a previous study proposed a statistically based approach to denote treatment outcome, translating pretest and posttest scores into clinically relevant categories, such as recovery and reliable improvement. We assessed the convergent validity of the Jacobson–Truax (JT) approach, using T‐score based cutoff values, with ratings by an independent evaluator.MethodsPretest and retest scores on the Brief Symptom Inventory (BSI) and clinical global impression improvement (CGI‐I) ratings were collected repeatedly through routine outcome monitoring from 5,900 outpatients with common mental disorders. Data were collected in everyday practice in a large mental health care provider.ResultsContinuous pretest‐to‐retest BSI change scores had a stronger association with CGI‐I than the categorical variable based on JT. However, JT categorization and improvement according to CGI converged substantially with association indices (Somers' D) ranging from D = .50 to .56. Discordance was predominantly due to a more positive outcome according to JT than on CGI‐I ratings.ConclusionConverting continuous outcome variables into clinically meaningful categories comes at the price of somewhat diminished concurrent validity with CGI‐I. Nevertheless, support was found for the proposed threshold values for reliable change and recovery, and the outcome denoted in these terms corresponded with CGI improvement for most patients.

An Improved Dropping Algorithm for Line-of-Sight Massive MIMO With Max-Min Power Control

In line-of-sight massive MIMO, there is a nonnegligible probability that two users become highly correlated, which leads to a reduction in the achievable sum-rates of linear precoders. In this letter, threshold values of a previously proposed dropping algorithm are found analytically to avoid repeating a large number of simulations to find the optimal threshold. These thresholds allow us to improve conjugate beamforming (CB) and zero-forcing (ZF) sum-rates with max–min power control. By using the proposed threshold values, the CB and ZF sum-rates are maximized, when there are only two correlated users. In addition, by using the derived thresholds, a modified dropping algorithm is proposed for channels with any number of correlated users. The results of the simulation scenarios show that at signal to noise ratio of 20 dB and 120 antennas at the base station, the modified algorithm improves the average CB and ZF sum-rates up to 36% and 5%, respectively.

How to recognize stent graft infection after endovascular aortic repair: the utility of 18F-FDG PET/CT in an infrequent but serious clinical setting

To evaluate the diagnostic performance of 18F-FDG PET/CT in the detection of stent graft infection (SGI). In a retrospective study, two nuclear medicine physicians have independently analyzed 17 18F-FDG PET/CT examinations performed for clinical suspicion of SGI. The images were evaluated for the uptake pattern and intensity, and by the maximum standard uptake value (SUVmax), the target-to-background ratio with blood pool (TBRBP) and liver uptake (TBRhep) as a reference. The SGI was defined as the presence of focal hyperactivity with an intensity exceeding hepatic uptake. CT images were independently assessed for signs of SGI. Clinical review of all further patients' data served as the standard of reference. Nine cases were established as SGI by the clinical review. PET/CT correctly diagnosed SGI in eight and yielded a sensitivity of 89% and specificity of 100%. The mean SUVmax, TBRBP, and TBRhep values were 9.8 ± 4.0, 6.9 ± 2.6, and 4.6 ± 1.7 in the group of patients with true SGI, and 4.0 ± 1.1, 2.5 ± 0.4 (p < 0.001) and 1.9 ± 0.2 (p < 0.001) in true negative cases, respectively. CT alone showed a sensitivity of 78% and specificity of 100% and was concordant with PET/CT in 14 cases. The best performing threshold values of SUVmax, TBRBP, and TBRhep were 5.6, 3.5, and 2.2, respectively. 18F-FDG PET/CT with expert evaluation, semiquantitative and quantitative image analysis with the proposed threshold values for SUVmax, TBRBP, and TBRhep has good diagnostic accuracy in the detection of SGI. We propose that visual grading scale for SGI should use hepatic uptake as a visual reference.

IgG4-positive Cell Quantification Distinguishes Between Inflammatory and Noninflammatory Diseases of the Orbit.

IgG4-related ophthalmic disease (IgG4-ROD) is a rare inflammatory disorder often refractory to corticosteroids and prone to recurrence. IgG4-ROD may frequently lack the characteristic histopathological features seen in other organs. Thus, the criteria for diagnosis of IgG4-ROD relies on elevated IgG4 cells seen on biopsied tissue. Proposed threshold levels of IgG4 to diagnose IgG4-ROD are currently based on a limited understanding of this cell type's presence in the orbit. This study seeks to describe the population of IgG4 in inflammatory and noninflammatory orbital tissues. A tertiary care center's pathology database was searched with keywords "orbit" or "orbital" from 1995 to 2013. Specimens meeting the selection criteria were evaluated, and regions of highest inflammation were identified and immunostained with IgG4 and CD138 antibodies. Immunohistochemical quantification proceeded as previously established by the international consensus criteria. Eighteen cases without a history of orbital inflammation were included as controls and were evaluated as above. Specimens from 68 inflammatory and 18 noninflammatory orbits met the selection criteria. Pathologist interreader correlation coefficient on quantification was >0.70 (P<0.001). The mean IgG4+/high powered field (HPF) and IgG4+/CD138 was 10.3 and 0.1 in inflammatory tissues and 0.5 and 0.01 in noninflammatory tissues, respectively. The spearman rho correlation coefficient between IgG4/HPF and IgG4+/CD138+ was >0.95 (P<0.0001). The mean IgG4/HPF in our study reached previously proposed threshold values for diagnosis of IgG4-ROD, illustrating the need for further discussion regarding diagnostic criteria of IgG4-ROD.

A Framework for Prioritizing the TESS Planetary Candidates Most Amenable to Atmospheric Characterization

A key legacy of the recently launched the Transiting Exoplanet Survey Satellite (TESS) mission will be to provide the astronomical community with many of the best transiting exoplanet targets for atmospheric characterization. However, time is of the essence to take full advantage of this opportunity. The James Webb Space Telescope (JWST), although delayed, will still complete its nominal five year mission on a timeline that motivates rapid identification, confirmation, and mass measurement of the top atmospheric characterization targets from TESS. Beyond JWST, future dedicated missions for atmospheric studies such as the Atmospheric Remote-sensing Infrared Exoplanet Large-survey (ARIEL) require the discovery and confirmation of several hundred additional sub-Jovian size planets (Rp < 10 R⊕) orbiting bright stars, beyond those known today, to ensure a successful statistical census of exoplanet atmospheres. Ground-based extremely large telescopes (ELTs) will also contribute to surveying the atmospheres of the transiting planets discovered by TESS. Here we present a set of two straightforward analytic metrics, quantifying the expected signal-to-noise in transmission and thermal emission spectroscopy for a given planet, that will allow the top atmospheric characterization targets to be readily identified among the TESS planet candidates. Targets that meet our proposed threshold values for these metrics would be encouraged for rapid follow-up and confirmation via radial velocity mass measurements. Based on the catalog of simulated TESS detections by Sullivan et al., we determine appropriate cutoff values of the metrics, such that the TESS mission will ultimately yield a sample of ∼300 high-quality atmospheric characterization targets across a range of planet size bins, extending down to Earth-size, potentially habitable worlds.

Potentially toxic elements in the riparian soils of the Sava River

PurposeRiparian zone contamination is a growing problem for several European catchments due to high anthropogenic pressures. This study investigates As, Cd, Cr, Cu, Ni, Pb, and Zn concentrations in the Sava River riparian zone, characterized by wide agricultural areas, various geological substrates, and different types of industrial pollution. The accumulation and mobility of these elements were studied because they are listed as priority substances in the Water Framework Directive and environmental objectives for surface waters.Materials and methodsSampling was performed during the sampling campaign of the EU 7th FW-funded GLOBAQUA project in September 2015 during a low-water event. Soil samples were collected along the Sava River at 12 selected sampling sites, from a depth of 0–30 cm, at a distance of 10–15 m from the river bank. The extent of pollution was estimated by determining total and readily soluble element concentrations in the soils. Potential ecological risk and the source of the selected elements in the soils was determined using the enrichment factor (EF), potential ecological risk index (RI), and statistical methods such as the principal component analysis (PCA) and multiple linear regression analysis (MLRA).Results and discussionThis study showed that concentrations of the selected elements increase along the Sava. In terms of origin, PCA and MLRA indicated that Cr and Ni in soils are predominantly lithogenic, while As, Cd, Pb, and Zn are both lithogenic and anthropogenic (ore deposits, industry, and agriculture). PCA singled out Cu since its origin in soil is most probably from specific point-source pollution. EF was generally minor to moderate for most of the examined elements, apart from Cu, for which the EF was significant at one sampling site. Overall ecological risk (RI) fell within the low-risk category for most sites, apart from Belgrade sampling site (BEO), where high total Cd content affected individual and overall ecological risk indicators, indicating Cd could represent a considerable ecological risk for the downstream riparian zone.ConclusionsAt downstream sites, there was a noticeable increase in PTE content, with Cd, Cr, Ni, and Zn exceeding the proposed threshold values for European soils, indicating rising contamination in riparian soils. In terms of the ecological risk, only Cd could pose a potential ecological threat for the downstream riparian zone.

Optimal selection of threshold in EIT reconstructed images for Estimating size of Objects

It is useful to convert reconstructed images to binary form for quantitatively establishing shapes and sizes of objects. In this work, we present guidelines for selecting appropriate threshold values based on systematic numerical investigations assuming prior knowledge of conductivity contrast. Various configurations of objects immersed in a background were considered. Open source software electrical impedance diffused optical reconstruction software (EIDORS) was used for reconstructing differential EIT images for these configurations. Diametric conductivity profiles were used to identify appropriate values of threshold to obtain accurate object size over a wide range of contrast. The calculated values of threshold and the resulting effect on estimated object size were compared with the usually preferred thresholds of 1/2 (FWHM) and 1/4 (FWQM) of maximum amplitude on the basis of size accuracy. It was found that the proposed threshold offers better size accuracy with respect to change in position and size of the object over a wide range of contrasts. The proposed threshold values were found to work satisfactorily for 15 dB signal to noise ratio and 10% error in conductivity contrast.