Reusable radiochromic hackmanite with gamma exposure memory.

Radiochromic films are used as position-sensitive dose meters in e.g. medical physics and radiation processing. The currently available films like those based on lithium-10,12-pentacosdiynoate or leucomalachite green are either toxic or non-reusable, or both. There is thus a great need for a sustainable solution for radiochromic detection. In the present work, we present a suitable candidate: hackmanite with the general formula Na8Al6Si6O24(Cl,S)2. This material is known as a natural intelligent material capable of changing color when exposed to ultraviolet radiation or X-rays. Here, we show for the first time that hackmanites are also radiochromic when exposed to alpha particles, beta particles (positrons) or gamma radiation. Combining experimental and computational data we elucidate the mechanism of gamma-induced radiochromism in hackmanites. We show that hackmanites can be used for gamma dose mapping in high dose applications as well as a memory material that has the one-of-a-kind ability to remember earlier gamma exposure. In addition to satisfying the requirements of sustainability, hackmanites are non-toxic and the films made of hackmanite are reusable thus showing great potential to replace the currently available radiochromic films.

Corrigendum: Multi-Dimensional Plant Element Stoichiometry-Looking Beyond Carbon, Nitrogen, and Phosphorus.

[This corrects the article DOI: 10.3389/fpls.2020.00023.].

Multi-Dimensional Plant Element Stoichiometry-Looking Beyond Carbon, Nitrogen, and Phosphorus.

Nutrient elements are important for plant growth. Element stoichiometry considers the balance between different nutrients and how this balance is affected by the environment. So far, focus of plant stoichiometry has mainly been on the three elements carbon (C), nitrogen (N), and phosphorus (P), but many additional elements are essential for proper plant growth. Our overall aim is to test the scaling relations of various additional elements (K, Ca, Mg, S, Cu, Zn, Fe, Mn), by using ten data sets from a range of plant functional types and environmental conditions. To simultaneously handle more than one element, we define a stoichiometric niche volume as the volume of an abstract multidimensional shape in n dimensions, with the n sides of this shape defined by the plant properties in question, here their element concentrations. Thus, a stoichiometric niche volume is here defined as the product of element concentrations. The volumes of N and P (VNP ) are used as the basis, and we investigate how the volume of other elements (VOth ) scales with respect to VNP¸ with the intention to explore if the concentrations of other elements increase faster (scaling exponent > 1) or slower (<1) than the concentrations of N and P. For example, scaling exponents >1 suggest that favorable conditions for plant growth, i.e., environments rich in N and P, may require proportionally higher uptake of other essential elements than poor conditions. We show that the scaling exponent is rather insensitive to environmental conditions or plant species, and ranges from 0.900 to 2.479 (average 1.58) in nine out of ten data sets. For single elements, Mg has the smallest scaling exponent (0.031) and Mn the largest (2.147). Comparison between laboratory determined stoichiometric relations and field observations suggest that element uptake in field conditions often exceeds the minimal physiological requirements. The results provide evidence for the view that the scaling relations previously reported for N and P can be extended to other elements; and that N and P are the driving elements in plant stoichiometric relations. The stoichiometric niche volumes defined here could be used to predict plant performances in different environments.

Generic parameters of first-order kinetics accurately describe soil organic matter decay in bare fallow soils over a wide edaphic and climatic range.

The conventional soil organic matter (SOM) decay paradigm considers the intrinsic quality of SOM as the dominant decay limitation with the result that it is modelled using simple first-order decay kinetics. This view and modelling approach is often criticized for being too simplistic and unreliable for predictive purposes. It is still under debate if first-order models can correctly capture the variability in temporal SOM decay observed between different agroecosystems and climates. To address this question, we calibrated a first-order model (Q) on six long-term bare fallow field experiments across Europe. Following conventional SOM decay theory, we assumed that parameters directly describing SOC decay (rate of SOM quality change and decomposer metabolism) are thermodynamically constrained and therefore valid for all sites. Initial litter input quality and edaphic interactions (both local by definition) and microbial efficiency (possibly affected by nutrient stoichiometry) were instead considered site-specific. Initial litter input quality explained most observed kinetics variability, and the model predicted a convergence toward a common kinetics over time. Site-specific variables played no detectable role. The decay of decades-old SOM seemed mostly influenced by OM chemistry and was well described by first order kinetics and a single set of general kinetics parameters.

Modelling the influence of ectomycorrhizal decomposition on plant nutrition and soil carbon sequestration in boreal forest ecosystems.

Tree growth in boreal forests is limited by nitrogen (N) availability. Most boreal forest trees form symbiotic associations with ectomycorrhizal (ECM) fungi, which improve the uptake of inorganic N and also have the capacity to decompose soil organic matter (SOM) and to mobilize organic N ('ECM decomposition'). To study the effects of 'ECM decomposition' on ecosystem carbon (C) and N balances, we performed a sensitivity analysis on a model of C and N flows between plants, SOM, saprotrophs, ECM fungi, and inorganic N stores. The analysis indicates that C and N balances were sensitive to model parameters regulating ECM biomass and decomposition. Under low N availability, the optimal C allocation to ECM fungi, above which the symbiosis switches from mutualism to parasitism, increases with increasing relative involvement of ECM fungi in SOM decomposition. Under low N conditions, increased ECM organic N mining promotes tree growth but decreases soil C storage, leading to a negative correlation between C stores above- and below-ground. The interplay between plant production and soil C storage is sensitive to the partitioning of decomposition between ECM fungi and saprotrophs. Better understanding of interactions between functional guilds of soil fungi may significantly improve predictions of ecosystem responses to environmental change.

Production and turnover of ectomycorrhizal extramatrical mycelial biomass and necromass under elevated CO2 and nitrogen fertilization.

Extramatrical mycelia (EMM) of ectomycorrhizal fungi are important in carbon (C) and nitrogen (N) cycling in forests, but poor knowledge about EMM biomass and necromass turnovers makes the quantification of their role problematic. We studied the impacts of elevated CO2 and N fertilization on EMM production and turnover in a Pinus taeda forest. EMM C was determined by the analysis of ergosterol (biomass), chitin (total bio- and necromass) and total organic C (TOC) of sand-filled mycelium in-growth bags. The production and turnover of EMM bio- and necromass and total C were estimated by modelling. N fertilization reduced the standing EMM biomass C to 57% and its production to 51% of the control (from 238 to 122 kg C ha(-1)  yr(-1) ), whereas elevated CO2 had no detectable effects. Biomass turnover was high (˜13 yr(-1) ) and unchanged by the treatments. Necromass turnover was slow and was reduced from 1.5 yr(-1) in the control to 0.65 yr(-1) in the N-fertilized treatment. However, TOC data did not support an N effect on necromass turnover. An estimated EMM production ranging from 2.5 to 6% of net primary production stresses the importance of its inclusion in C models. A slow EMM necromass turnover indicates an importance in building up forest humus.

Closure of mesenteric defects in laparoscopic gastric bypass: a multicentre, randomised, parallel, open-label trial.

BACKGROUND: Small bowel obstruction due to internal hernia is a common and potentially serious complication after laparoscopic gastric bypass surgery. Whether closure of surgically created mesenteric defects might reduce the incidence is unknown, so we did a large randomised trial to investigate. METHOD: This study was a multicentre, randomised trial with a two-arm, parallel design done at 12 centres for bariatric surgery in Sweden. Patients planned for laparoscopic gastric bypass surgery at any of the participating centres were offered inclusion. During the operation, a concealed envelope was opened and the patient was randomly assigned to either closure of mesenteric defects beneath the jejunojejunostomy and at Petersen's space or non-closure. After surgery, assignment was open label. The main outcomes were reoperation for small bowel obstruction and severe postoperative complications. Outcome data and safety were analysed in the intention-to-treat population. This trial is registered with ClinicalTrials.gov, number NCT01137201. FINDINGS: Between May 1, 2010, and Nov 14, 2011, 2507 patients were recruited to the study and randomly assigned to closure of the mesenteric defects (n=1259) or non-closure (n=1248). 2503 (99·8%) patients had follow-up for severe postoperative complications at day 30 and 2482 (99·0%) patients had follow-up for reoperation due to small bowel obstruction at 25 months. At 3 years after surgery, the cumulative incidence of reoperation because of small bowel obstruction was significantly reduced in the closure group (cumulative probability 0·055 for closure vs 0·102 for non-closure, hazard ratio 0·56, 95% CI 0·41-0·76, p=0·0002). Closure of mesenteric defects increased the risk for severe postoperative complications (54 [4·3%] for closure vs 35 [2·8%] for non-closure, odds ratio 1·55, 95% CI 1·01-2·39, p=0·044), mainly because of kinking of the jejunojejunostomy. INTERPRETATION: The results of our study support the routine closure of the mesenteric defects in laparoscopic gastric bypass surgery. However, closure of the mesenteric defects might be associated with increased risk of early small bowel obstruction caused by kinking of the jejunojejunostomy. FUNDING: Örebro County Council, Stockholm City Council, and the Erling-Persson Family Foundation.

Intra-abdominal hypertension--an experimental study of early effects on intra-abdominal metabolism.

BACKGROUND: The main aim of this experimental study was to investigate the early effects of intra-abdominal hypertension (IAH) on intra-abdominal metabolism and intestinal mucosal blood flow to evaluate whether metabolites can serve as markers for organ dysfunction during IAH. METHODS: A swine model was used, and the animals were anesthetized and ventilated. Fifteen animals were subjected to IAH of 30 mm Hg for 4 hr by carbon dioxide insufflation. Seven animals served as controls. Hemodynamic data, arterial blood samples, and urine output were analyzed. Intraluminal laser Doppler flowmetry measured intestinal mucosal blood flow. Glucose, glycerol, lactate, and pyruvate concentrations and lactate-to-pyruvate (l/p) ratio were measured intraperitoneally and intramurally in the small intestine and rectum using microdialysis. RESULTS: IAH lowered the abdominal perfusion pressure by 12-18 mm Hg, reduced the intestinal mucosal blood flow by 45-63%, and decreased urine output by 50-80%. In the intervention group, glycerol concentrations increased at all locations, pyruvate concentrations decreased, and the l/p ratio increased intraperitoneally and intramurally in the small intestine. Control animals remained metabolically stable. Glucose and lactate concentrations were only slightly affected or unchanged in both the groups. CONCLUSIONS: IAH reduces intestinal blood flow and urinary output and causes early metabolic changes, indicating a discrete shift toward anaerobic metabolism. Intraperitoneal microdialysis may be useful in the early detection of impaired organ dysfunction with metabolic consequences in IAH and abdominal compartment syndrome.

Temperature sensitivity of soil respiration rates enhanced by microbial community response.

Soils store about four times as much carbon as plant biomass, and soil microbial respiration releases about 60 petagrams of carbon per year to the atmosphere as carbon dioxide. Short-term experiments have shown that soil microbial respiration increases exponentially with temperature. This information has been incorporated into soil carbon and Earth-system models, which suggest that warming-induced increases in carbon dioxide release from soils represent an important positive feedback loop that could influence twenty-first-century climate change. The magnitude of this feedback remains uncertain, however, not least because the response of soil microbial communities to changing temperatures has the potential to either decrease or increase warming-induced carbon losses substantially. Here we collect soils from different ecosystems along a climate gradient from the Arctic to the Amazon and investigate how microbial community-level responses control the temperature sensitivity of soil respiration. We find that the microbial community-level response more often enhances than reduces the mid- to long-term (90 days) temperature sensitivity of respiration. Furthermore, the strongest enhancing responses were observed in soils with high carbon-to-nitrogen ratios and in soils from cold climatic regions. After 90 days, microbial community responses increased the temperature sensitivity of respiration in high-latitude soils by a factor of 1.4 compared to the instantaneous temperature response. This suggests that the substantial carbon stores in Arctic and boreal soils could be more vulnerable to climate warming than currently predicted.

Early complications after laparoscopic gastric bypass surgery: results from the Scandinavian Obesity Surgery Registry.

OBJECTIVE: To identify risk factors for serious and specific early complications of laparoscopic gastric bypass surgery using a large national cohort of patients. BACKGROUND: Bariatric procedures are among the most common surgical procedures today. There is, however, still a need to identify preoperative and intraoperative risk factors for serious complications. METHODS: From the Scandinavian Obesity Surgery Registry database, we identified 26,173 patients undergoing primary laparoscopic gastric bypass operation for morbid obesity between May 1, 2007, and September 30, 2012. Follow-up on day 30 was 95.7%. Preoperative data and data from the operation were analyzed against serious postoperative complications and specific complications. RESULTS: The overall risk of serious postoperative complications was 3.4%. Age (adjusted P = 0.028), other additional operation [odds ratio (OR) = 1.50; confidence interval (CI): 1.04-2.18], intraoperative adverse event (OR = 2.63; 1.89-3.66), and conversion to open surgery (OR = 4.12; CI: 2.47-6.89) were all risk factors for serious postoperative complications. Annual hospital volume affected the rate of serious postoperative complications. If the hospital was in a learning curve at the time of the operation, the risk for serious postoperative complications was higher (OR = 1.45; CI: 1.22-1.71). The 90-day mortality rate was 0.04%. CONCLUSIONS: Intraoperative adverse events and conversion to open surgery are the strongest risk factors for serious complications after laparoscopic gastric bypass surgery. Annual operative volume and total institutional experience are important for the outcome. Patient related factors, in particular age, also increased the risk but to a lesser extent.

Health care use during 20 years following bariatric surgery.

CONTEXT: Bariatric surgery results in sustained weight loss; reduced incidence of diabetes, cardiovascular events, and cancer; and improved survival. The long-term effect on health care use is unknown. OBJECTIVE: To assess health care use over 20 years by obese patients treated conventionally or with bariatric surgery. DESIGN, SETTING, AND PARTICIPANTS: The Swedish Obese Subjects study is an ongoing, prospective, nonrandomized, controlled intervention study conducted in the Swedish health care system that included 2010 adults who underwent bariatric surgery and 2037 contemporaneously matched controls recruited between 1987 and 2001. Inclusion criteria were age 37 years to 60 years and body mass index of 34 or higher in men and 38 or higher in women. Exclusion criteria were identical in both groups. INTERVENTIONS: Of the surgery patients, 13% underwent gastric bypass, 19% gastric banding, and 68% vertical-banded gastroplasty. Controls received conventional obesity treatment. MAIN OUTCOME MEASURES: Annual hospital days (follow-up years 1 to 20; data capture 1987-2009; median follow-up 15 years) and nonprimary care outpatient visits (years 2-20; data capture 2001-2009; median follow-up 9 years) were retrieved from the National Patient Register, and drug costs from the Prescribed Drug Register (years 7-20; data capture 2005-2011; median follow-up 6 years). Registry linkage was complete for more than 99% of patients (4044 of 4047). Mean differences were adjusted for baseline age, sex, smoking, diabetes status, body mass index, inclusion period, and (for the inpatient care analysis) hospital days the year before the index date. RESULTS: In the 20 years following their bariatric procedure, surgery patients used a total of 54 mean cumulative hospital days compared with 40 used by those in the control group (adjusted difference, 15; 95% CI, 2-27; P = .03). During the years 2 through 6, surgery patients had an accumulated annual mean of 1.7 hospital days vs 1.2 days among control patients (adjusted difference, 0.5; 95% CI, 0.2 to 0.7; P < .001). From year 7 to 20, both groups had a mean annual 1.8 hospital days (adjusted difference, 0.0; 95% CI, -0.3 to 0.3; P = .95). Surgery patients had a mean annual 1.3 nonprimary care outpatient visits during the years 2 through 6 vs 1.1 among the controls (adjusted difference, 0.3; 95% CI, 0.1 to 0.4; P = .003), but from year 7, the 2 groups did not differ (1.8 vs 1.9 mean annual visits; adjusted difference, -0.2; 95% CI, -0.4 to 0.1; P = .12). From year 7 to 20, the surgery group incurred a mean annual drug cost of US $930; the control patients, $1123 (adjusted difference, -$228; 95% CI, -$335 to -$121; P < .001). CONCLUSIONS: Compared with controls, surgically treated patients used more inpatient and nonprimary outpatient care during the first 6-year period after undergoing bariatric surgery but not thereafter. Drug costs from years 7 through 20 were lower for surgery patients than for control patients. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT01479452.

Environmental and stoichiometric controls on microbial carbon-use efficiency in soils.

Carbon (C) metabolism is at the core of ecosystem function. Decomposers play a critical role in this metabolism as they drive soil C cycle by mineralizing organic matter to CO(2). Their growth depends on the carbon-use efficiency (CUE), defined as the ratio of growth over C uptake. By definition, high CUE promotes growth and possibly C stabilization in soils, while low CUE favors respiration. Despite the importance of this variable, flexibility in CUE for terrestrial decomposers is still poorly characterized and is not represented in most biogeochemical models. Here, we synthesize the theoretical and empirical basis of changes in CUE across aquatic and terrestrial ecosystems, highlighting common patterns and hypothesizing changes in CUE under future climates. Both theoretical considerations and empirical evidence from aquatic organisms indicate that CUE decreases as temperature increases and nutrient availability decreases. More limited evidence shows a similar sensitivity of CUE to temperature and nutrient availability in terrestrial decomposers. Increasing CUE with improved nutrient availability might explain observed declines in respiration from fertilized stands, while decreased CUE with increasing temperature and plant C : N ratios might decrease soil C storage. Current biogeochemical models could be improved by accounting for these CUE responses along environmental and stoichiometric gradients.

Plant stoichiometry at different scales: element concentration patterns reflect environment more than genotype.

All plant species require at least 16 elements for their growth and survival but the relative requirements and the variability at different organizational scales is not well understood. We use a fertiliser experiment with six willow (Salix spp.) genotypes to evaluate a methodology based on Euclidian distances for stoichiometric analysis of the variability in leaf nutrient relations of twelve of those (C, N, P, K, Ca, Mg, Mn, S, Fe, Zn, B, Cu) plus Na and Al. Differences in availability of the elements in the environment was the major driver of variation. Variability between leaves within a plant or between individuals of the same genotype growing in close proximity was as large as variability between genotypes. Elements could be grouped by influence on growth: N, P, S and Mn concentrations follow each other and increase with growth rate; K, Ca and Mg uptake follow the increase in biomass; but uptake of Fe, B, Zn and Al seems to be limited. The position of Cu lies between the first two groups. Only for Na is there a difference in element concentrations between genotypes. The three groups of elements can be associated with different biochemical functions.

Nutrient limitation on terrestrial plant growth--modeling the interaction between nitrogen and phosphorus.

Growth of plants in terrestrial ecosystems is often limited by the availability of nitrogen (N) or phosphorous (P) Liebig's law of the minimum states that the nutrient in least supply relative to the plant's requirement will limit the plant's growth. An alternative to the law of the minimum is the multiple limitation hypothesis (MLH) which states that plants adjust their growth patterns such that they are limited by several resources simultaneously. We use a simple model of plant growth and nutrient uptake to explore the consequences for the plant's relative growth rate of letting plants invest differentially in N and P uptake. We find a smooth transition between limiting elements, in contrast to the strict transition in Liebig's law of the minimum. At N : P supply ratios where the two elements simultaneously limit growth, an increase in either of the nutrients will increase the growth rate because more resources can be allocated towards the limiting element, as suggested by the multiple limitation hypothesis. However, the further the supply ratio deviates from these supply rates, the more the plants will follow the law of the minimum. Liebig's law of the minimum will in many cases be a useful first-order approximation.

Evaluation of Monte Carlo-based calibrations of HPGe detectors for in situ gamma-ray spectrometry.

The aim of this work was to evaluate the use of Monte Carlo-based calibrations for in situ gamma-ray spectrometry. We have performed in situ measurements at five different sites in Sweden using HPGe detectors to determine ground deposition activity levels of (137)Cs from the 1986 Chernobyl accident. Monte Carlo-calculated efficiency calibration factors were compared with corresponding values calculated using a more traditional semi-empirical method. In addition, results for the activity ground deposition were also compared with activity densities found in soil samples. In order to facilitate meaningful comparisons between the different types of results, the combined standard uncertainty of in situ measurements was assessed for both calibration methods. Good agreement, both between the two calibration methods, and between in situ measurements and soil samples, was found at all five sites. Uncertainties in in situ measurements for the given measurement conditions, about 20 years after the fallout occurred, were found to be in the range 15-20% (with a coverage factor k=1, i.e. with a confidence interval of about 68%).

Uncertainty in HPGe detector calibrations for in situ gamma-ray spectrometry.

Semi-empirical methods are often used for efficiency calibrations of in situ gamma-ray spectrometry measurements with high-purity germanium detectors. The intrinsic detector efficiency is experimentally determined for different photon energies and angles of incidence, and a suitable expression for the efficiency is fitted to empirical data. In this work, the combined standard uncertainty of such an efficiency function for two detectors was assessed. The uncertainties in individual efficiency measurements were found to be about 1.9 and 3.1% (with a coverage factor k = 1, i.e. with a confidence interval of about 68%) for the two detectors. The main contributions to these uncertainties were found to originate from uncertainties in source-to-detector distance, source activity and full-energy peak count rate. The standard uncertainties of the fitted functions were found to be somewhat higher than the uncertainty of individual data points, i.e. 5.2 and 8.1% (k = 1). With the introduction of a new expression for the detector efficiency, these uncertainties were reduced to 3.7 and 4.2%, i.e. with up to a factor of two. Note that this work only addresses the uncertainty in the determination of intrinsic detector efficiency.

Effects of bariatric surgery on mortality in Swedish obese subjects.

BACKGROUND: Obesity is associated with increased mortality. Weight loss improves cardiovascular risk factors, but no prospective interventional studies have reported whether weight loss decreases overall mortality. In fact, many observational studies suggest that weight reduction is associated with increased mortality. METHODS: The prospective, controlled Swedish Obese Subjects study involved 4047 obese subjects. Of these subjects, 2010 underwent bariatric surgery (surgery group) and 2037 received conventional treatment (matched control group). We report on overall mortality during an average of 10.9 years of follow-up. At the time of the analysis (November 1, 2005), vital status was known for all but three subjects (follow-up rate, 99.9%). RESULTS: The average weight change in control subjects was less than +/-2% during the period of up to 15 years during which weights were recorded. Maximum weight losses in the surgical subgroups were observed after 1 to 2 years: gastric bypass, 32%; vertical-banded gastroplasty, 25%; and banding, 20%. After 10 years, the weight losses from baseline were stabilized at 25%, 16%, and 14%, respectively. There were 129 deaths in the control group and 101 deaths in the surgery group. The unadjusted overall hazard ratio was 0.76 in the surgery group (P=0.04), as compared with the control group, and the hazard ratio adjusted for sex, age, and risk factors was 0.71 (P=0.01). The most common causes of death were myocardial infarction (control group, 25 subjects; surgery group, 13 subjects) and cancer (control group, 47; surgery group, 29). CONCLUSIONS: Bariatric surgery for severe obesity is associated with long-term weight loss and decreased overall mortality.

The likely impact of elevated [CO2], nitrogen deposition, increased temperature and management on carbon sequestration in temperate and boreal forest ecosystems: a literature review.

Temperate and boreal forest ecosystems contain a large part of the carbon stored on land, in the form of both biomass and soil organic matter. Increasing atmospheric [CO2], increasing temperature, elevated nitrogen deposition and intensified management will change this C store. Well documented single-factor responses of net primary production are: higher photosynthetic rate (the main [CO2] response); increasing length of growing season (the main temperature response); and higher leaf-area index (the main N deposition and partly [CO2] response). Soil organic matter will increase with increasing litter input, although priming may decrease the soil C stock initially, but litter quality effects should be minimal (response to [CO2], N deposition, and temperature); will decrease because of increasing temperature; and will increase because of retardation of decomposition with N deposition, although the rate of decomposition of high-quality litter can be increased and that of low-quality litter decreased. Single-factor responses can be misleading because of interactions between factors, in particular those between N and other factors, and indirect effects such as increased N availability from temperature-induced decomposition. In the long term the strength of feedbacks, for example the increasing demand for N from increased growth, will dominate over short-term responses to single factors. However, management has considerable potential for controlling the C store.

In situ gamma-ray spectrometry for environmental monitoring: a semi empirical calibration method.

In situ gamma spectrometry using high-purity germanium (HPGe) detectors is a frequently used method for the determination of radionuclide ground deposition levels. Such measurements do, however, require an efficiency calibration based on detector sensitivity and parameters such as soil density and vertical activity distribution. In this work, a novel expression is used for the detector efficiency, incorporating both the influence of photon energy and incidence angle. Detector-specific efficiency data are determined empirically. For the theoretical calculation of the photon fluence at the detector, a three-layer model of finite thickness is developed for the description of soil density and vertical activity distribution. In order to facilitate the calibration of in situ measurements, a PC program has been developed to enable rapid, on-site calculations of radionuclide ground deposition levels. The semi empirical calibration method was tested on in situ measurements with two different detectors, and the results show good agreement with results obtained from traditional soil sampling.