Quantifying methane emissions from rice fields in the Taihu Lake region, China by coupling a detailed soil database with biogeochemical model

As China has approximately 22% of the world's rice paddies, the regional quantification of CH<sub>4</sub> emissions from these paddies is important in determining their contribution to the global greenhouse gas effect. This paper reports the use of a biogeochemical model (DeNitrification and DeComposition or DNDC) for quantifying CH<sub>4</sub> emissions from rice fields in the Taihu Lake region of China. For this application, the DNDC model was linked to a 1:50 000 soil database derived from 1107 paddy soil profiles compiled during the Second National Soil Survey of China in the 1980s–1990s. The simulated results showed that the 2.3 Mha of paddy rice fields in the Taihu Lake region emitted the equivalent of 5.7 Tg C from 1982–2000, with the average CH<sub>4</sub> flux ranging from 114 to 138 kg C ha<sup>−1</sup> y<sup>−1</sup>. As for soil subgroups, the highest emission rate (660 kg C ha<sup>−1</sup> y<sup>−1</sup>) was linked to gleyed paddy soils accounting for about 4.4% of the total area of paddy soils. The lowest emission rate (91 kg C ha<sup>−1</sup> y<sup>−1</sup>) was associated with degleyed paddy soils accounting for about 18% of the total area of paddy soils. The most common soil in the area was hydromorphic paddy soils, which accounted for about 53% of the total area of paddy soils with a CH<sub>4</sub> flux of 106 kg C ha<sup>−1</sup> y<sup>−1</sup>. On a regional basis, the annual averaged CH<sub>4</sub> flux in the Taihu Lake plain soil region and alluvial plain soil region were higher than that in the low mountainous and hilly soil region and the polder soil region. The model simulation was conducted with two databases using polygons or counties as the basic units. The county-based database contained soil information coarser than the polygon system built based on the 1:50 000 soil database. The modeled results with the two databases found similar spatial patterns of CH<sub>4</sub> emissions in the Taihu Lake region. However, discrepancies exist between the results from the two methods. The total CH<sub>4</sub> emissions generated from the polygon-based database is 2.6 times the minimum CH<sub>4</sub> emissions generated from the county-based database, and is 0.98 times the maximum CH<sub>4</sub> emissions generated from the county-based database. The average value of the relative deviation ranged from −20% to 98% for most counties, which indicates that a more precise soil database is necessary to better simulate CH<sub>4</sub> emissions from rice fields in the Taihu Lake region using the DNDC model

Mechanical Testing of 3D Printed Prosthetics

The Rapid Orthotics for CURE Kenya team as a whole aims to empower the orthopedic technicians in the CURE Kenya hospital by creating, optimizing, and testing 3D printed prosthetics and orthotics. Our team started in 2016 by creating a 3D printing process for below the knee prosthetic sockets. Since then, we had adapted to the hospital\u27s needs over the years, expanding the capabilities of the system itself. Presently, a section of our team has worked specifically with these leg sockets to ensure the safety and functionality for patients. They have done testing to make sure the sockets are strong enough and to make sure the silicone liners are safe for use in developing countries. In addition to safety testing, over the years we have created ankle-foot orthotics and prosthetic hands. The design part of our team works to create new 3D printed devices to help our clients reach more patients. By 2024 we hope to fully integrate our expanded system in the orthopedic workshop in Kijabe, Kenya.https://mosaic.messiah.edu/engr2020/1018/thumbnail.jp

Evidence for Secretion of a Netrin-1-like Protein by Tetrahymena thermophila

Netrin-1 is a pleiotropic signaling molecule with targets in many mammalian cell types. Though first characterized as a chemotactic signal involved in neuronal guidance during development, netrin-1 has since been found to have a regulatory role in angiogenesis, and is also used as a biomarker in certain cancers. Tetrahymena thermophila are free-living protists that rely on chemotactic signals to find food, as well as to escape predators. Chemoattractants cause the cells to swim faster in the forward direction, while chemorepellents cause ciliary reversal, resulting in movement of the cell away from the noxious stimulus. We have previously found that netrin-1 is a chemorepellent in T. thermophila. More recently, we have detected netrin-1 by ELISA in both whole cell extract and secreted protein samples obtained from T. thermophila. In addition, we have immunolocalized netrin-1 staining to the cytosol of T. thermophila using an anti-netrin-1 antibody. We are currently running Western blots to determine the molecular weight of this protein and compare it to its vertebrate counterparts. Further experimentation is needed to determine the physiological role of this protein in T. thermophila

The determination of gypsum in soils

2 Pags. © Soil Science Society of America. This is an open access article distributed under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).This chapter of Soil Analysis Methods by Herrero et al. (2016) presents and discusses three simple gravimetric and spectroscopic methods for gypsum determination. First they present the Artieda method (Artieda et al., 2006) and second the Lebron method (Lebron et al., 2009), both based on measuring different water exchanges between the atmosphere and gypsum. The third presented method (Weindorf et al., 2013) uses the determination of specific chemical elements via portable X-ray fluorescence (XRF) spectroscopy as a proxy for gypsum determination; a key advantage being, this approach is field portable. These three methods use few, if any, chemicals and only rudimentary lab equipment.The funding of the project I-coop 2016SU0015 by CSIC made possible this note, written in in the framework of the Letter of Intent between CSIC and TTU.Peer reviewe

Soil Gypsum Determination

6 pags. Peer-reviewed Book Chapter. Copyright © by the Soil Science Society of America, Inc.The methods for gypsum content determination in soils are summarized and their applicability discussed. Special attention is given to the critical step of sample preparation, stressing the elimination of the oven heating at temperatures surpassing 40°C. Wet methods are unsuitable for soils rich in gypsum or containing other sulfates. Instead, oven-based methods playing on the mass variations due to the release of constitutional water of gypsum are preferable. Under laboratory settings, we recommend two existing methods: one directly measuring the loss of mass on heating and the other exploiting the gypsum–bassanite phase change under controlled conditions. Both reflectance and X-ray fluorescence (XRF) provide nondestructive methods for quick gypsum appraisal, and combining both methods increases the accuracy. The results are easily calibrated with gravimetric methods.Peer reviewe

Plant elemental composition and portable X-rayfluore scence (pXRF) spectroscopy:quantification under differentanalytical parameters

Emergence of portable X-ray fluorescence (pXRF) systems presents new opportunities for rapid, low-cost plant analysis, both as a lab system and in situ system. Numerous studies have extolled the virtues of using pXRF for a wide range of plant applications, however, for many such applications, there is need for further assessment with regards to analytical parameters for plant analysis. While pXRF is a potential powerful research tool for elemental composition analysis, its successful use in plant analysis is made more likely by having an understanding of X-ray physics, calibration process, and ability to test a variety of homogenous and well-characterized materials for developing a matrix-specific calibration. Because potential pXRF users may often underestimate the complexity of proper analysis, this study aims at providing a technical background for plant analysis using pXRF. The focus is on elemental quantification under different analytical parameters and different methods of sample presentation: direct surface contact under vacuum, placement in a sample cup with prolene as a seal, and without the aid of a vacuum. Direct analysis on the surface of a pXRF provided highest sensitivity and accuracy (R2 > 0.90) for light elements (Mg to P). Sulfur, K, and Ca can be reliably measured without the aid of a vacuum (R2 > 0.99, 0.97, and 0.93 respectively), although lower detection limits may be compromised. pXRF instruments provide plant data of sufficient accuracy for many applications and will reduce the overall time and budget compared with the use of conventional techniques. Sensitivity and accuracy are dependent on the instrument's settings, make, and model. © 2015 The Authors. X-Ray Spectrometry published by John Wiley & Sons, Ltd