Research on Efficient Seismic Data Acquisition Methods Based on Sparsity Constraint

In actual exploration,the demand for 3D seismic data collection is increasing,and the requirements for data are becoming higher and higher.Accordingly,the collection cost and data volume also increase.Aiming at this problem,we make use of the nature of data sparse expression,based on the theory of compressed sensing,to carry out the research on the efficient collection method of seismic data.It combines the collection of seismic data and the compression in data processing in practical work,breaking through the limitation of the traditional sampling frequency,and the sparse characteristics of the seismic signal are utilized to reconstruct the missing data.We focus on the key elements of the sampling matrix in the theory of compressed sensing,and study the methods of seismic data acquisition.According to the conditions that the compressed sensing sampling matrix needs to meet,we introduce a new random acquisition scheme,which introduces the widely used Low-density Parity-check(LDPC)sampling matrix in image processing into seismic exploration acquisition.Firstly,its properties are discussed and its conditions for satisfying the sampling matrix in compressed sensing are verified.Then the LDPC sampling method and the conventional data acquisition method are used to synthesize seismic data reconstruction experiments.The reconstruction results,signal-to-noise ratio and reconstruction error are compared to verify the seismic data based on sparse constraints.The LDPC sampling method improves the current seismic data reconstruction efficiency,reduces the exploration cost and the effectiveness and feasibility of the method.

Improving the efficiency and effectiveness of global phosphorus use: focus on root and rhizosphere levels in the agronomic system

Phosphorus(P)is essential for life and for efficient crop production,but global P use with limited recycling is inefficient in several sectors,including agronomy.Unfortunately,plant physiologists,agronomists,farmers and end users employ different measures for P use efficiency(PUE),which often masks their values at different scales.The term P use effectiveness,which also considers energetic and sustainability measures in addition to P balances,is also a valuable concept.Major physiological and genetic factors for plant P uptake and utilization have been identified,but there has been limited success in genetically improving PUE of modern crop cultivars.In maize,studies on root architectural and morphological traits appear promising.Rhizosphere processes assist in mobilizing and capturing sparingly soluble phosphate from rock phosphate.Combinations of phosphate-solubilizing microorganisms with ammonium-based nitrogen fertilizer,as well as strategies of fertilizer placement near the roots of target crops,can moderately enhance PUE.The desired concentration of P in the products differs,depending on the final use of the crop products as feed,food or for energy conversion,which should be considered during crop production.

Complex Regulation of Plant Phosphate Transporters and the Gap between Molecular Mechanisms and Practical Application： What Is Missing？

It has been almost 25 years since the first report of the gene encoding a high-affinity phosphate transporter （PT）, PH084, in yeast. Since then, an increasing number of yeast PH084 homologs as well as other genes encoding proteins with phosphate （Pi） transport activities have been identified and functionally characterized in diverse plant species. Great progress has been made also in deciphering the molecular mechanism underlying the regulation of the abundance and/or activity of these genes and their products. The regulatory genes affect plant Pi homeostasis commonly through direct or indirect regulation of the abundance of PTs at different levels. However, little has been achieved in the use of PTs for developing genetically modified crops with high phosphorus use efficiency （PUE）. This might be a consequence of overemphasizing Pi uptake from the rhizosphere and lack of knowledge about the roles of PTs in Pi transport and recycling within the plant that are required to optimize PUE. Here, we mainly focused on the genes encoding proteins with Pi transport activities and the emerging understanding of their regulation at the transcriptional, posttranscriptional, translational, and post-translational levels. In addition, we propose potential strategies for effective use of PTs in improving plant growth and development.

Plant adaptation to low phosphorus availability:Core signaling,crosstalks,and applied implications

Phosphorus(P)is an essential nutrient for plant growth and reproduction.Plants preferentially absorb P as orthophosphate(Pi),an ion that displays low solubility and that is readily fixed in the soil,making P limita-tion a condition common to many soils and Pi fertilization an inefficient practice.To cope with Pi limitation,plants have evolved a series of developmental and physiological responses,collectively known as the Pi starvation rescue system(PSR),aimed to improve Pi acquisition and use efficiency(PUE)and protect from Pi-starvation-induced stress.Intensive research has been carried out during the last 20 years to un-ravel the mechanisms underlying the control of the PSR in plants.Here we review the results of this research effort that have led to the identification and characterization of several core Pi starvation signaling components,including sensors,transcription factors,microRNAs(miRNAs)and miRNA inhibitors,kinases,phosphatases,and components of the proteostasis machinery.We also refer to recent results revealing the existence of intricate signaling interplays between Pi and other nutrients and antagonists,N,Fe,Zn,and As,that have changed the initial single-nutrient-centric view to a more integrated view of nutrient homeostasis.Finally,we discuss advances toward improving PUE and future research priorities.