Soil Moisture Sensing via Swept Frequency Based Microwave Sensors

There is a need for low-cost, high-accuracy measurement of water content in various materials. This study assesses the performance of a new microwave swept frequency domain instrument (SFI) that has promise to provide a low-cost, high-accuracy alternative to the traditional and more expensive time domain reflectometry (TDR). The technique obtains permittivity measurements of soils in the frequency domain utilizing a through transmission configuration, transmissometry, which provides a frequency domain transmissometry measurement (FDT). The measurement is comparable to time domain transmissometry (TDT) with the added advantage of also being able to separately quantify the real and imaginary portions of the complex permittivity so that the measured bulk permittivity is more accurate that the measurement TDR provides where the apparent permittivity is impacted by the signal loss, which can be significant in heavier soils. The experimental SFI was compared with a high-end 12 GHz TDR/TDT system across a range of soils at varying soil water contents and densities. As propagation delay is the fundamental measurement of interest to the well-established TDR or TDT technique; the first set of tests utilized precision propagation delay lines to test the accuracy of the SFI instrument’s ability to resolve propagation delays across the expected range of delays that a soil probe would present when subjected to the expected range of soil types and soil moisture typical to an agronomic cropping system. The results of the precision-delay line testing suggests the instrument is capable of predicting propagation delays with a RMSE of +/−105 ps across the range of delays ranging from 0 to 12,000 ps with a coefficient of determination of r2 = 0.998. The second phase of tests noted the rich history of TDR for prediction of soil moisture and leveraged this history by utilizing TDT measured with a high-end Hewlett Packard TDR/TDT instrument to directly benchmark the SFI instrument over a range of soil types, at varying levels of moisture. This testing protocol was developed to provide the best possible comparison between SFI to TDT than would otherwise be possible by using soil moisture as the bench mark, due to variations in soil density between soil water content levels which are known to impact the calibration between TDR’s estimate of soil water content from the measured propagation delay which is converted to an apparent permittivity measurement. This experimental decision, to compare propagation delay of TDT to FDT, effectively removes the errors due to variations in packing density from the evaluation and provides a direct comparison between the SFI instrument and the time domain technique of TDT. The tests utilized three soils (a sand, an Acuff loam and an Olton clay-loam) that were packed to varying bulk densities and prepared to provide a range of water contents and electrical conductivities by which to compare the performance of the SFI technology to TDT measurements of propagation delay. For each sample tested, the SFI instrument and the TDT both performed the measurements on the exact same probe, thereby both instruments were measuring the exact same soil/soil-probe response to ensure the most accurate means to compare the SFI instrument to a high-end TDT instrument. Test results provided an estimated instrumental accuracy for the SFI of +/−0.98% of full scale, RMSE basis, for the precision delay lines and +/−1.32% when the SFI was evaluated on loam and clay loam soils, in comparison to TDT as the bench-mark. Results from both experiments provide evidence that the low-cost SFI approach is a viable alternative to conventional TDR/TDT for high accuracy applications

Topsoil carbon stocks in urban greenspaces of the Hague, the Netherlands

Industrial Ecolog

Ten-year experience of a national multidisciplinary tumour board for cancer and pregnancy in the Netherlands

Background: Most physicians encounter pregnant women with cancer incidentally, leading to a lack of expertise or confidence to inform and treat these patients based on the most recent guidelines and expert opinions. In the Netherlands, a national multidisciplinary tumour board for cancer, infertility and pregnancy (CIP-MDT) was founded in December 2012, including 35 specialists from a variety of disciplines. This study evaluates the frequency of consultation of the CIP-MDT, the types of questions asked and the satisfaction of consulting physicians with its existence. Methodology: Of all requests to the CIP-MDT between December 2012 and June 2021, tumour type, stage, gestational age at diagnosis and recommendations were collected and analysed. For evaluating the methods of the CIP-MDT, a survey with questions regarding experiences with the CIP-MDT and its impact on treatment decisions was sent out to physicians that consulted the CIP-MDT. Results: Recommendations (n = 213) concerned preferred and safest options for imaging, treatment options during pregnancy, possible effects on the child and fertility preserving options. Most frequently discussed malignancies were breast cancer (n = 66), cervical cancer (n = 34), haematological malignancies (n = 32) and melanoma (n = 21). The questionnaire was completed by 54% of the physicians (n = 50). Satisfaction with the recommendations of the CIP-MDT was high, and 94% of the physicians informed their patients about consulting the CIP-MDT and felt supported by the received recommendations. Discussion: The national Dutch CIP-MDT contributes to a high level of satisfaction among physicians requesting advice. Further research should be executed to confirm that a CIP-MDT improves the outcomes for pregnant women and their children

Proton therapy of a pregnant patient with nasopharyngeal carcinoma

Background and purpose: Radiotherapy during pregnancy is rarely administered due to lack of data and practical challenges. This is the first detailed report of proton therapy as cancer treatment for a pregnant patient with nasopharyngeal carcinoma. Materials and methods: Pencil beam scanning proton therapy was prescribed to a pregnant patient to a total dose of 70 Gy (RBE) to the therapeutic CTV and 54.25 Gy to the prophylactic CTV, delivered in 35 fractions with a simultaneous integrated boost technique. Results: Phantom measurements showed a thirty-fold decrease in fetal radiation dose when using proton compared to photon therapy, with a total fetal dose of 5.5 mSv for the complete proton treatment, compared to 185 and 298 mSv for the photon treatment with and without lead shielding, respectively. After adminstering proton therapy during pregnancy, at 39 weeks of gestation, a healthy boy with a birthweight on the 83th percentile was delivered. Pediatric follow-up at 2 months of age of the offspring showed normal growth and age-adequate motor development with no signs of neurological problems. MR follow-up of the tumor 3 months after the end of treatment showed complete remission. Conclusion: This case demonstrates the potential of proton therapy for treatment during pregnancy. Compared to photon therapy, proton therapy can significantly limit fetal dose, while simultaneously offering a more optimized treatment to the patient

Measured and Predicted Solute Transport in a Tile Drained Field

Most solute transport measurement techniques are tedious and require extensive soil excavation. A field experiment was conducted to evaluate whether surface transport properties determined by a nondestructive time domain reflectometry (TDR) technique could be used to accurately predict tile flux concentrations. A 14 by 14 m field plot selected above a 1.1-m deep tile drain was studied. Low electrical conductivity (EC) water was sprinkled on the plot surface, and after reaching a steady-state condition, a pulse of calcium chloride solution (16.3 cm) with an EC of 23 dS m−1 was applied through the same sprinklers. Time domain reflectometry equipment was used to record the change in EC of surface (∼ top 2 cm) soil at 45 locations. The EC of the tile drainage flow was measured continuously with an EC probe. The surface convective lognormal transfer (CLT) function parameters, log mean irrigation depth, μI, and its standard deviation, σI, were found to be 3.44 and 0.94 [ln(cm)], respectively, for a reference depth of 110 cm. These surface parameters were used in a one-dimensional (1-D) CLT model and in a two-dimensional (2-D) model (CLT vertical function combined with exponential horizontal transfer function) to predict the tile flux concentrations. The 1-D CLT model predicted an earlier arrival time of chemicals to the tile drain than observed values. The root mean square error, RMSE, of the 1-D CLT predictions was 0.123, and the coefficient of efficiency, E, was −0.47. The 2-D model predictions of tile flux concentrations were similar to the observed values. The root mean squared errors (RMSE) and E were 0.023 and 0.94, respectively. The findings suggest that in this field soil, the surface solute transport properties determined by TDR could be combined with a 2-D transport model to make reasonable predictions of tile flux concentrations

Chapter 14 Electrical Properties of Soils

This chapter discusses the electric and electromagnetic methods that are used to evaluate the electrical properties of soils. Electric techniques exploit the flow of a steady-state current in the subsurface, while electromagnetic methods rely on the phenomenon of electromagnetic induction and the wave character of the electromagnetic field. The electrical techniques and associated properties are: (a) spontaneous potential methods in which the formation of water resistivity is determined; (b) resistivity methods in which the apparent resistivity can be calculated using Wenner, Schlumberger, and dipole-dipole arrays; and (c) specific conductivity methods in which the soil-specific conductivity is calculated by incorporating in the analysis of soil geometric factors, such as fabric anisotropy, tortuosity, resistance to solid matrix, bulk fluid phase, and electric double layer. Various parameters that influence the measured electrical properties are also presented, such as the nature of the soil composition (particle size distribution, mineralogy), soil structure (porosity, pore size distribution, connectivity, and anisotropy), moisture content, temperature, concentration of dissolved species in the pore-solution, wet-dry cycles, age of contaminants, and mineral formation due to biodegradation. Finally, the extraction of aquifer hydraulic properties such as porosity and hydraulic conductivity, from the measured electrical properties is discussed

Meta-analysis of epigenome-wide association studies in neonates reveals widespread differential DNA methylation associated with birthweight

Birthweight is associated with health outcomes across the life course, DNA methylation may be an underlying mechanism. In this meta-analysis of epigenome-wide association studies of 8,825 neonates from 24 birth cohorts in the Pregnancy And Childhood Epigenetics Consortium, we find that DNA methylation in neonatal blood is associated with birthweight at 914 sites, with a difference in birthweight ranging from -183 to 178 grams per 10% increase in methylation (P-Bonferroni <1.06 x 10(-7)). In additional analyses in 7,278 participants,Peer reviewe