An Empirical Model for Estimating Soil Thermal Diffusivity from Texture, Bulk Density, and Degree of Saturation

Soil thermal diffusivity κ is an essential parameter for studying surface and subsurface heat transfer and temperature changes. It is well understood that κ mainly varies with soil texture, water content θ, and bulk density ρb, but few models are available to accurately quantify the relationship. In this study, an empirical model is developed for estimating κ from soil particle size distribution, ρb, and degree of water saturation Sr. The model parameters are determined by fitting the proposed equations to heat-pulse κdata for eight soils covering wide ranges of texture, ρb, and Sr. Independent evaluations with published κdata show that the new model describes the κ(Sr) relationship accurately, with root-mean-square errors less than 0.75 × 10−7 m2 s−1. The proposed κ(Sr) model also describes the responses of κ to ρb changes accurately in both laboratory and field conditions. The new model is also used successfully for predicting near-surface soil temperature dynamics using the harmonic method. The results suggest that this model provides useful estimates of κ from Sr, ρb, and soil texture

Summary of Advances in the Heat-Pulse Technique: Improvements in Measuring Soil Thermal Properties

This essay provides a summary of “Advances in the Heat-Pulse Technique: Improvements in Measuring Soil Thermal Properties” recently appearing in Methods of Soil Analysis. Series

2-Amino-nicotinamide induces apoptosis of prostate cancer cells via inhibition of PI3K/AKT and phosphorylation of STA3/JAK2

Purpose: To study the cytotoxicity of 2-amino-nicotinamide against prostate cancer (PCa) cells, and the underlying molecular mechanism.Methods: The effect of 2-amino-nicotinamide on cell viability and apoptosis was determined by 3-(4,5- dimethylthiazol-2-yl)-2,5-diphenyltetrazolium (MTT) and flow cytometry, respectively, while its effect on cellular production of fluorescent-oxidized product from DCFH-DA was measured using flow cytometry. Apoptosis-related protein expressions were evaluated by western blot assay.Results: 2-Amino-nicotinamide produced cytotoxicity against MCF-7, SGC7901, PCa 22Rv1 and LNCaP cancer cell lines (p < 0.05). Mechanistic data revealed that 2-amino-nicotinamide activated apoptosis, and enhanced cleavage of PARP and caspase-3 in PCa 22Rv1 and LNCaP cells. In PCa 22Rv1 and LNCaP cell lines, cytochrome C and Bax levels were enhanced by treatment with 2-aminonicotinamide, while Bcl-2 protein level was suppressed (p < 0.05). Activated expressions of PI3K, Akt and ERK in PCa 22Rv1 and LNCaP cells were down-regulated, while p38 expression was increased.Moreover, 2-amino-nicotinamide suppressed the activation of JAK2 and STAT3, but did not alter total JAK2 and STAT3 levels in PCa 22Rv1 and LNCaP cells (p < 0.05).Conclusion: 2-Amino-nicotinamide exerts cytotoxic effects on prostate carcinoma cells via activation of apoptosis and down-regulation of PI3K/AKT and STA3/JAK2. Thus, 2-amino nicotinamide is a potential bioactive agent for prostate cancer management. Keywords: 2-Amino-nicotinamide, Apoptosis, Fluorescent-oxidized, Cytotoxicit

An Improved Thermo-TDR Technique for Monitoring Soil Thermal Properties, Water Content, Bulk Density, and Porosity

The thermo-time domain reflectometry (thermo-TDR) technique is valuable for monitoring in situ soil water content (θ), thermal properties, bulk density (ρb), porosity (n), and air-filled porosity (na) in the vadose zone. However, the previous thermo-TDR sensor has several weaknesses, including limited precision of TDR waveforms due to the short probe length, small measurement volume, and thermal property estimation errors resulting from finite probe properties not accounted for by the heat pulse method. We have developed a new thermo-TDR sensor design for monitoring θ, thermal properties, ρb, n, and na. The new sensor has a robust heater probe (outer diameter of 2.38 mm and length of 70 mm) and a 10-mm spacing between the heater and sensing probes, which provides a sensing volume three times larger than that of the previous sensor. The identical cylindrical perfect conductors and the tangent line–second-order bounded mean oscillation theories were applied to analyze the raw data. Laboratory tests showed that θ values determined with the new sensor had a RMSE of 0.014 m3 m−3 compared with 0.016 to 0.026 m3 m−3 with the previous sensor. Soil thermal property estimates with the new sensor agreed well with modeled values. Soil ρb, n, and na derived from θ and thermal properties were consistent with those derived from gravimetric measurements. Thus, the new thermo-TDR sensor provides more accurate θ, thermal properties, ρb, n, and na values than the previous sensor

IMECE2002-32838 CONVECTION EFFECTS IN THREE-DIMENSIONAL DENDRITIC GROWTH

ABSTRACT A phase-field model is developed to simulate free dendritic growth coupled with fluid flow for a pure material in three dimensions. The preliminary results presented here illustrate the strong influence of convection on the three-dimensional (3D) dendrite growth morphology. The detailed knowledge of the flow and temperature fields in the melt around the dendrite from the simulations allows for a detailed understanding of the convection effects on dendritic growth

Summary of Thermo–Time Domain Reflectometry Method: Advances in Monitoring In Situ Soil Bulk Density

Soil bulk density (ρb) is a key indicator of soil compaction and soil health that relates to water infiltration, plant rooting depth, nutrient availability, and soil microbial activity. Under field conditions, ρb usually varies with time and depth because of agronomic practices, root growth, and environmental processes (e.g., rainfall events, wetting/drying, and freezing/thawing). The traditional technique (i.e., the coring method) for determining ρb has the problems of destructive sampling, labor intensive, and is unable to capture the spatial and temporal variations. In a chapter of the recent Methods of Soil Analysis book, we present a review of the theory, instrumentation, and procedures of the thermo–time domain reflectometry (thermo-TDR) technique for monitoring in situ ρb (Lu et al., 2017)

Applications of Thermo-TDR Sensors for Soil Physical Measurements

Advanced sensors provide new opportunities to improve the understanding of soil properties and processes. One such sensor is the thermo-TDR sensor, which combines the functions of heat pulse probes and time domain reflectometry probes. Recent advancements in fine-scale measurements of soil thermal, hydraulic, and electrical properties with the thermo-TDR sensor enable measuring soil state variables (temperature, water content, and ice content), thermal and electrical properties (thermal diffusivity, heat capacity, thermal conductivity, and bulk electrical conductivity), structural parameters (bulk density and air-filled porosity) and fluxes (heat, water, and vapor) simultaneously. This chapter describes the theory, methodology, and potential applications of the thermo-TDR technique

Transcriptome profiling in rumen, reticulum, omasum, and abomasum tissues during the developmental transition of pre-ruminant to the ruminant in yaks

The development of the four stomachs of yak is closely related to its health and performance, however the underlying molecular mechanisms are largely unknown. Here, we systematically analyzed mRNAs of four stomachs in five growth time points [0 day, 20 days, 60 days, 15 months and 3 years (adult)] of yaks. Overall, the expression patterns of DEmRNAs were unique at 0 d, similar at 20 d and 60 d, and similar at 15 m and adult in four stomachs. The expression pattern in abomasum was markedly different from that in rumen, reticulum and omasum. Short Time-series Expression Miner (STEM) analysis demonstrated that multi-model spectra are drastically enriched over time in four stomachs. All the identified mRNAs in rumen, reticulum, omasum and abomasum were classified into 6, 4, 7, and 5 cluster profiles, respectively. Modules 9, 38, and 41 were the most significant three colored modules. By weighted gene co-expression network analysis (WGCNA), a total of 5,486 genes were categorized into 10 modules. CCKBR, KCNQ1, FER1L6, and A4GNT were the hub genes of the turquoise module, and PAK6, TRIM29, ADGRF4, TGM1, and TMEM79 were the hub genes of the blue module. Furthermore, functional KEGG enrichment analysis suggested that the turquoise module was involved in gastric acid secretion, sphingolipid metabolism, ether lipid metabolism, etc., and the blue module was enriched in pancreatic secretion, pantothenate and CoA biosynthesis, and starch and sucrose metabolism, etc. Our study aims to lay a molecular basis for the study of the physiological functions of rumen, reticulum, omasum and abomasum in yaks. It can further elucidate the important roles of these mRNAs in regulation of growth, development and metabolism in yaks, and to provide a theoretical basis for age-appropriate weaning and supplementary feeding in yaks