Enclosure Rather Than Topography Enhances the Soil Ecological Stoichiometry in Typical Steppe on the Loess Plateau, China

Grassland is one of the largest terrestrial ecosystems in the world, a large part of which is distributed in varied topography. And grazing and enclosure are the main ways to use this part. Grazing changes the soil structure through feeding, trampling and excreta return, thus affects the soil nutrients. The aspect mainly affects soil temperature and moisture by affecting solar radiation. The slope affects soil nutrients by affecting surface runoff. Water and temperature are the main factors affecting soil nutrients. We carried out to explore the effect of enclosure years and topography on soil ecological stoichiometry. The results showed that: soil organic carbon density, soil nitrogen density and soil phosphorus density increased with the increasing enclosure years and decreased with the increasing slope. Soil N/P (ratio between soil nitrogen density and soil phosphorus density) increased with increasing the enclosure years and the slope while soil C/N (ratio between soil organic carbon density and soil nitrogen density) decreased. Soil C/P (ratio between soil organic carbon density and soil phosphorus density) increased with the increasing enclosure years, however the trend with slope change was not obvious. The enclosure of sunny slope is more beneficial to soil nutrient accumulation

Fe and MN Concentrations in Plants Correlated Negatively With Air Temperature Precipitation in Three Types of Grassland

Alpine meadows, typical steppe, and deserts are globally important grassland ecosystems. We investigated the seasonal trends in Fe and Mn concentrations in the dominant species and community of plants from diverse grassland types in northwest China. It was found that seasonal Fe and Mn concentrations in most plant species were negatively correlated with seasonal precipitation, biomass, and temperature. Additionally, seasonal Cu concentrations in Reaumuria soongorica was significantly correlated with seasonal precipitation. The seasonal mean temperature explained more of the seasonal variation of the Fe and Mn concentrations in the plant community of these grasslands than precipitation, except for the concentrations of Mn in typical steppe vegetation. However, there was almost no significant correlation between these factors and the seasonal Cu and Zn concentrations. These results provided a scientific basis for the assessment of plant trace elements in alpine meadows, typical steppes, and deserts around the world

Multimodal Remote Sensing Image Registration Based on Adaptive Multi-scale PIIFD

In recent years, due to the wide application of multi-sensor vision systems, multimodal image acquisition technology has continued to develop, and the registration problem based on multimodal images has gradually emerged. Most of the existing multimodal image registration methods are only suitable for two modalities, and cannot uniformly register multiple modal image data. Therefore, this paper proposes a multimodal remote sensing image registration method based on adaptive multi-scale PIIFD(AM-PIIFD). This method extracts KAZE features, which can effectively retain edge feature information while filtering noise. Then adaptive multi-scale PIIFD is calculated for matching. Finally, the mismatch is removed through the consistency of the feature main direction, and the image alignment transformation is realized. The qualitative and quantitative comparisons with other three advanced methods shows that our method can achieve excellent performance in multimodal remote sensing image registration

Optimization of Protein-Protein Interaction Measurements for Drug Discovery Using AFM Force Spectroscopy

Increasingly targeted in drug discovery, protein-protein interactions challenge current high throughput screening technologies in the pharmaceutical industry. Developing an effective and efficient method for screening small molecules or compounds is critical to accelerate the discovery of ligands for enzymes, receptors and other pharmaceutical targets. Here, we report developments of methods to increase the signal-to-noise ratio (SNR) for screening protein-protein interactions using atomic force microscopy (AFM) force spectroscopy. We have demonstrated the effectiveness of these developments on detecting the binding process between focal adhesion kinases (FAK) with protein kinase B (Akt1), which is a target for potential cancer drugs. These developments include optimized probe and substrate functionalization processes and redesigned probe-substrate contact regimes. Furthermore, a statistical-based data processing method was developed to enhance the contrast of the experimental data. Collectively, these results demonstrate the potential of the AFM force spectroscopy in automating drug screening with high throughput