Linear Thermodynamics of Rodlike DNA Filtration

Linear thermodynamics transportation theory is employed to study filtration of rodlike DNA molecules. Using the repeated nanoarray consisting of alternate deep and shallow regions, it is demonstrated that the complex partitioning of rodlike DNA molecules of different lengths can be described by traditional transport theory with the configurational entropy properly quantified. Unlike most studies at mesoscopic level, this theory focuses on the macroscopic group behavior of DNA transportation. It is therefore easier to conduct validation analysis through comparison with experimental results. It is also promising in design and optimization of DNA filtration devices through computer simulation.Singapore-MIT Alliance (SMA

Tuning the emission properties of a fluorescent polymer using a polymer microarray approach - identification of an optothermo responsive polymer

Fluorescent polymer microarrays were prepared using inkjet printing and screened. The fluorescence intensity was found to be tunable by temperature change when the dye was immobilized in identified thermo-responsive polymer beads.</p

Periodic oscillations of the relativistic pendulum with friction

We consider the existence and multiplicity of periodic oscillations for the forced pendulum model with relativistic effects by using the Poincare-Miranda theorem. Some detailed information about the bound for the period of forcing term is obtained. To support our analytical work, we also consider a forced pendulum oscillator with the special force $\gamma_0\sin(\omega t)$ including a sufficiently small parameter. The result shows us that for all $\omega\in(0,+\infty)$, there exists a $2\pi/\omega$ periodic solution under our settings

Analysis of Lightning and Precipitation Activities in Three Severe Convective Events Based on Doppler Radar and Microwave Radiometer over the Central China Region

Hubei Province Region (HPR), located in Central China, is a concentrated area of severe convective weather. Three severe convective processes occurred in HPR were selected, namely 14&ndash;15 May 2015 (Case 1), 6&ndash;7 July 2013 (Case 2), and 11&ndash;12 September 2014 (Case 3). In order to investigate the differences between the three cases, the temporal and spatial distribution characteristics of cloud&ndash;ground lightning (CG) flashes and precipitation, the distribution of radar parameters, and the evolution of cloud environment characteristics (including water vapor (VD), liquid water content (LWC), relative humidity (RH), and temperature) were compared and analyzed by using the data of lightning locator, S-band Doppler radar, ground-based microwave radiometer (MWR), and automatic weather stations (AWS) in this study. The results showed that 80% of the CG flashes had an inverse correlation with the spatial distribution of heavy rainfall, 28.6% of positive CG (+CG) flashes occurred at the center of precipitation (&gt;30 mm), and the percentage was higher than that of negative CG (&minus;CG) flashes (13%). Moreover, the quantity of thunderstorm cells in Case 1 was more than other cases, the peak time of +CG flashes was prior to that of total CG flashes in Case 2 and Case 3, and the time of +CG flashes&rsquo; peak in Case 2 was prior to that of precipitation at about 2 h. Based on the analysis of the cloud environment, there are three main reasons for the differences of CG flashes and precipitation. Firstly, the structure of the LWC vertical profile and the height of the LWC peak are different, and high LWC makes it difficult for the collision of ice particles to generate electricity. Secondly, the differences between convective available potential energy (CAPE), precipitation, and CG flashes is caused by the sudden increase of VD from 1.5 km to 3 km, and thirdly, the production of CG flashes is very sensitive to RH at the surface layer and the total CG flashes increase as the RH increasing

Effects of Mixed Phase Microphysical Process on Precipitation in a Simulated Convective Cloud

The effects of the liquid water content (LWC) and mixing ratio of hydrometeors in the simulation of convective precipitation in Wuhan, Hubei Province, China, are investigated using a three-dimensional convective rainstorm model. The microphysical processes of warm and cold clouds are considered into microphysical parameterization. The warm-cloud process is dominated by the combined effects of condensation and drop coalescence. The cold-cloud process is initiated mainly by production of graupel, and the microphysical parameterizations are used to predict the mixing ratio of cloud droplets, rain, ice crystals, snow, and graupel. The simulations results show that 80% rainfall is derived from warm cloud microphysical processes, and the rest is produced by cold cloud microphysical processes. The mixed phase microphysical process can invigorate the production of convective rainfall and enhance the liquid water content (LWC). In addition, the vertical distribution of LWC is mainly concentrated at the height isotherms of −10 to −20 °C in precipitation and the concentration area of LWC matches the distribution range of graupel particles. However, the growth of graupel particles depend on the microphysical processes of nucleation and propagation between rain and graupel particles (NUrg) and collision and coalescence between cloud droplets and graupel (CLcg), in which NUrg is a major source of graupel particles and the contribution of the process accounts for 77% of the amount of graupel particles

A High-Fidelity Parametric Model for Tropical Cyclone Boundary Layer Wind Field by Considering Effects of Land Cover and Terrain

The proper simulation of the tropical cyclone (TC) boundary layer wind field is essential to predict the maximum wind speed, the imposed wind loading on civil structures, and the related potential disasters. A high-fidelity parametric model is developed to produce the wind field and to study the wind characteristics of TCs in the boundary layer. This model adopts a widely used boundary layer turbulence closure scheme and is built on a terrain-following coordinate system, which can consider various land cover and terrain effects. To improve the computational efficiency, a nested grid system is adopted. The developed model is implemented to reproduce the wind fields of Hurricane Isabel (2003), Hurricane Katrina (2005), Hurricane Irene (2011), Typhoon Hagupit (2008), Typhoon Hato (2017), and Typhoon Mangkhut (2018). Different types of observation datasets are used to validate the developed model, including the Hurricane Research Division\u27s H*Wind snapshots, the National Data Buoy Center\u27s wind records, and several meteorological sounding stations\u27 observations. The spatial wind fields and the wind speed time series are presented. The influence of land cover and terrain on the behavior of TC is investigated. The simulation results demonstrate the high-fidelity and computational efficiency of the developed model, implying its potential applications for TC hazard modeling

Selection and validation of reference genes for real-time quantitative PCR in hyperaccumulating ecotype of Sedum alfredii under different heavy metals stresses.

Real-time Quantitative PCR (RT-qPCR) has become an effective method for accurate analysis of gene expression in several biological systems as well as under different experimental conditions. Although with high sensitivity, specificity and broad dynamic range, this method requires suitable reference genes for transcript normalization in order to guarantee reproducible and meaningful results. In the present study, we evaluated five traditional housekeeping genes and five novel reference genes in Hyperaccumulating ecotype of Sedum alfredii, a well known hyperaccumulator for heavy metals phytoremediation, under Cd, Pb, Zn and Cu stresses of seven different durations. The expression stability of these ten candidates were determined with three programs--geNorm, NormFinder and BestKeeper. The results showed that all the selected reference genes except for SAND could be used for RT-qPCR normalization. Among them UBC9 and TUB were ranked as the most stable candidates across all samples by three programs together. For the least stable reference genes, however, BestKeeper produced different results compared with geNorm and NormFinder. Meanwhile, the expression profiles of PCS under Cd, Pb, Zn and Cu stresses were assessed using UBC9 and TUB respectively, and similar trends were obtained from the results of the two groups. The distinct expression patterns of PCS indicated that various strategies could be taken by plants in adaption to different heavy metals stresses. This study will provide appropriate reference genes for further gene expression quantification using RT-qPCR in Hyperaccumulator S. alfredii

Transcriptome analysis of immature xylem in the Chinese fir at different developmental phases

Background.Chinese fir [Cunninghamia lanceolata (Lamb.) Hook.] is one of the most important native tree species for timber production in southern China. An understanding of overall fast growing stage, stem growth stage and senescence stage cambium transcriptome variation is lacking. We used transcriptome sequencing to identify the repertoire of genes expressed during development of xylem tissue in Chinese fir, aiming to delineate the molecular mechanisms of wood formation. Results. We carried out transcriptome sequencing at three different cultivation ages (7Y, 15Y and 21Y) generating 68.71 million reads (13.88 Gbp). A total of 140,486 unigenes with a mean size of 568.64 base pairs (bp) were obtained via de novo assembly. Of these, 27,427 unigenes (19.52%) were further annotated by comparison to public protein databases. A total of 5,331 (3.79%) unigenes were mapped into 118 pathways by searching against the Kyoto Encyclopedia of Genes and Genomes Pathway database (KEGG). Differentially expressed genes (DEG) analysis identified 3, 16 and 5,899 DEGs from the comparison of 7Y vs. 15Y, 7Y vs. 21Y and 15Y vs. 21Y, respectively, in the immature xylem tissues, including 2,638 significantly up-regulated and 3,280 significantly down-regulated genes. Besides, five NAC transcription factors, 190 MYB transcription factors, and 34 WRKY transcription factors were identified respectively from Chinese fir transcriptome. Conclusion. Our results revealed the active transcriptional pathways and identified the DEGs at different cultivation phases of Chinese fir wood formation. This transcriptome dataset will aid in understanding and carrying out future studies on the molecular basis of Chinese fir wood formation and contribute to future artificial production and applications