Ecosystem service values and land use change in the opium poppy cultivation region in Northern Part of Lao PDR

Land use change and land-cover impacts ecosystem services and functions. In this paper according to the study area’s land use characteristic and ecosystem type, the Land use category of the study area was divided into seven categories, including Forest, Grassland, Farmland, Water, Wetlands, Urban land and Barren land. The dynamic information of the forest Land use change during 10 years was calculated by the map algebra in ArcGIS 9.2. Both in 1992 and in 2002, Forest and Grassland were two largest Land use category in the study area. Forest took up 44.7% and 39.4% of the total area, and Grassland was 50.13% and 50.72% of the total area in 1992 and 2002. Finally, we valued change in ecosystem services delivered by each land use category using coefficients published by Costanza et al. [5]. Ecosystem services value of study area, the total ecosystem services value of 10.6 million hectares of this study area decreased by 11.74%. From the coefficient of sensitivity (CS) was less than unity in all case, it indicated that the total ecosystem services values was relatively inelastic and the results suggest that we have to pay attention more on land use change and finally, policy for driving forces of land use change were developed.     

Estimation of gross primary production of irrigated maize using Landsat-8 imagery and Eddy Covariance data

A study was conducted to understand the potential of Landsat-8 in the estimation of gross primary production (GPP) and to quantify the productivity of maize crop cultivated under hyper-arid conditions of Saudi Arabia. The GPP of maize crop was estimated by using the Vegetation Photosynthesis Model (VPM) utilizing remote sensing data from Landsat-8 reflectance (GPP_VPM) as well as the meteorological data provided by Eddy Covariance (EC) system (GPP_EC), for the period from August to November 2015. Results revealed that the cumulative GPP_EC for the entire growth period of maize crop was 1871 g C m⁻². However, the cumulative GPP determined as a function of the enhanced vegetation index – EVI (GPP_EVI) was 1979 g C m⁻², and that determined as a function of the normalized difference vegetation index – NDVI (GPP_NDVI) was 1754 g C m⁻². These results indicated that the GPP_EVI was significantly higher than the GPP_EC (R² = 0.96, P = 0.0241 and RMSE = 12.6%). While, the GPP_NDVI was significantly lower than the GPP_EC (R² = 0.93, P = 0.0384 and RMSE = 19.7%). However, the recorded relative error between the GPP_EC and both the GPP_EVI and the GPP_NDVI was −6.22% and 5.76%, respectively. These results demonstrated the potential of the landsat-8 driven VPM model for the estimation of GPP, which is relevant to the productivity and carbon fluxes.     

Assessing the effect of EWDP on vegetation restoration by remote sensing in the lower reaches of Tarim River

In this study, effect of ecological water diversion on vegetation restoration in the lower reaches of Tarim River is assessed by coupling remote sensing techniques and a field-based survey. Land use/cover and fractional vegetation coverage (Fvc) maps derived from remote sensing images, ground validation data, and hydrological observation data are adopted to analyze the responses of Ecological Water Diversion Project (EWDP). The results indicate that, the EWDP has showed a positive effect on vegetation restoration in the lower part of Tarim Basin. During 2001 to 2013, transformation from unused land to nature vegetation (i.e. forest land, grassland and scrubland) was the major process of land use/cover change; the area of natural vegetation showed a 4.7% increase, and the area of unused land reduced by 6.8%. Landscape patch size was decreased, the degree of fragmentation and diversity of landscape was increased, and landscape structure in the study area became more complex. Moreover, vegetation coverage promoted from 2001 to 2013; average Fvc in 2013 was 1.5 times greater than that in 2001. The results can provide not only an accurate assessment for the EWDP, but also a visual insight for the water resources management practices in the study area, such that the sustainability for local ecosystem can be facilitated.     

Structural basis for ligand recognition and discrimination of a quorum-quenching antibody

In the postantibiotic era, available treatment options for severe bacterial infections caused by methicillin-resistant Staphylococcus aureus have become limited. Therefore, new and innovative approaches are needed to combat such life-threatening infections. Virulence factor expression in S. aureus is regulated in a cell density-dependent manner using “quorum sensing,” which involves generation and secretion of autoinducing peptides (AIPs) into the surrounding environment to activate a bacterial sensor kinase at a particular threshold concentration. Mouse monoclonal antibody AP4-24H11 was shown previously to blunt quorum sensing-mediated changes in gene expression in vitro and protect mice from a lethal dose of S. aureus by sequestering the AIP signal. We have elucidated the crystal structure of the AP4-24H11 Fab in complex with AIP-4 at 2.5 Å resolution to determine its mechanism of ligand recognition. A key Glu^H95 provides much of the binding specificity through formation of hydrogen bonds with each of the four amide nitrogens in the AIP-4 macrocyclic ring. Importantly, these structural data give clues as to the interactions between the cognate staphylococcal AIP receptors AgrC and the AIPs, as AP4-24H11·AIP-4 binding recapitulates features that have been proposed for AgrC-AIP recognition. Additionally, these structural insights may enable the engineering of AIP cross-reactive antibodies or quorum quenching vaccines for use in active or passive immunotherapy for prevention or treatment of S. aureus infections.     

Enzymatic resolution of racemates with a ‘remote’ stereogenic center as an efficient tool in drug,flavor and vitamin synthesis

The enantioselective recognition of ‘remote’ stereogenic centers represents a scientific task in organic chemistry being also of current interest in the pharmaceutical industry. This is due to a range of pharmaceutically relevant molecules or intermediates thereof bearing a stereogenic center, which is separated from the functional group by a larger non-chiral moiety such as, for example, a longer sequence of bonds of at least three carbon or hetero-atoms or by a planar aromatic moiety. Notably, biocatalysis turned out to provide an excellent solution for a range of challenging syntheses in this field. For example, efficient enzymatic resolution processes of racemates with such a ‘remote’ stereogenic center were developed for the synthesis of pelitrexol, lasofoxifene and (S)-monastrol. In general, good yields accompanied by high enantioselectivities were obtained, thus underlining the tremendous potential of enzymes to recognize and enantioselectively transform enantiomers of racemates with ‘remote’ stereogenic centers. Such or similar types of stereoselective recognitions of ‘remote’ stereogenic centers by means of enzymes have been also reported in the field of flavor and vitamin synthesis. Thus, biocatalysis represents a promising solution for the efficient approach to enantiomerically pure complex chiral molecules with stereogenic centers being located apart from the functional group, and it can be expected that enzymatic resolution will be increasingly applied when searching for an efficient and also technically feasible process for also novel complex chiral molecules bearing a ‘remote’ stereogenic center.     

基于Bioperl实现远程自动获取抗逆基因序列

BioPerl对于现今大量的生物数据来说,具有很好的获取和处理能力,并且NCBI提供了可以直接访问它下属的Entrez数据库（包括PubMed）的编程接口,即E-Utilities。为了从NCBI中自动获取大量抗逆基因序列,使得生物抗逆基因二次数据库得以搭建,该文基于BioPerl设计了远程自动获取大量抗逆基因序列的程序。此程序灵巧、精悍,Perl语言强大的文本处理功能使程序能实现不同类型基因序列的远程获取。     

数字化远程介入手术示教的实践与思考

目的:探讨介入手术远程演示教学系统的应用及效果。方法:采取多机组、多屏幕实况转播,将导管室的高清血管造影图像、术野图像、全景图像传输到会场。结果:学员对介入手术远程转播满意度为100%,其中最满意的是转播交互环节。本次共进行10台手术远程转播,无一例转播相关并发症发生,患者对治疗评价均及保护隐私情况非常满意。基本实现了导管室与会场的双向音视频互动,学员同术者在手术过程中的直接交流起到了较好的教学效果。结论:介入手术演示已经成为继续医学教育必不可少的手段,数字化介入手术转播是将来介入手术转播的发展方向。     

基于分割的多尺度城市绿地景观

利用多分辨率分割生成3种尺度的城市绿地景观.以50像元和300像元的目标分割值生成小尺度和大尺度的景观影像目标层,利用最近邻法分类两个目标层.对小尺度景观分类后的结果进行分割生成中间尺度的景观影像目标层并进行分类.从3个景观尺度的分类目标层中矢量化提取出绿地信息并计算6个景观指数：多样性、优势度、均匀度和分维数、破碎度和内缘比.多样性、优势度、均匀度和分维数的最大值分别为2.2、0.681、0.948和0.326,最小分别为1.641、0.122、0.707和0.113.表明多样性、均匀度和破碎度随着景观尺度的增大而减小,优势度随着景观尺度的增大而增大.基于分割产生多尺度景观的方法可以满足城市绿地景观研究的需求.