表观反射率及其在植被遥感中的应用

 由于植被遥感应用定量化和监测等的需求,光学遥感数据的辐射校正更加受到重视。该文论述了辐射校正,辐射定标和大气校正的概念以及它们之间的区别及关系。特别对辐射定标的结果之一,大气层顶表观反射率,简称表观反射率(Apparent reflectance)的定义、概念、计算和它在植被遥感中的应用等方面,进行了详细的论述。     

一测多评法测定不同产地黄柏炭中4种生物碱含量

为建立同时测定不同产地黄柏炭中4种生物碱成分(黄柏碱、木兰花碱、小檗红碱、小檗碱)的一测多评法。实验以小檗碱为内参物,基于HPLC法建立小檗碱与其它成分的相对校正因子,并用校正因子计算4种成分的含量;用外标法和一测多评法同时测定30批黄柏炭样品的含量。结果表明30批黄柏炭样品的外标法与一测多评法结果之间无明显差异,说明了一测多评法的准确性和可行性。因此在缺乏对照品的情况下,以小檗碱为内参物同时测定黄柏碱、木兰花碱、小檗红碱的含量是可行的。该方法准确性和重复性良好,可用于黄柏炭的质量控制。     

Unrecognized and imperilled diversity in an endemic barb (Smiliogastrini,Enteromius) from the Fouta Djallon highlands

The Upper Guinean Forests of Guinea, Sierra Leone and Liberia contain high levels of freshwater biodiversity. The Guinean Range and associated Fouta Djallon highlands separate two biogeographical provinces in the region and served as a refugium during past climatic fluctuations. While many species of freshwater fishes are restricted to one biogeographical province or the other, some are reported to occur on both sides of the divide. Here, we examine the molecular and morphological diversity of an endemic small African barb, Enteromius foutensis, reported to occur in both provinces. This integrative analysis revealed unrecognized diversity and suggests recent, or ongoing, events that facilitated geodispersal and subsequent divergence in the region. The molecular analysis revealed three divergent and well‐supported populations within E. foutensis. Accounting for allometric shape variation allowed us to observe diagnostic morphological differences among the populations. Enteromius foutensis sensu stricto is restricted to the Little Scarcies drainage in Guinea and northern Sierra Leone. Our study revealed two candidate species distinct from E. foutensis. One is likely a narrow endemic restricted to a small area in the Konkouré River basin; the other candidate species inhabits the upper Senegal and Gambie River drainages. How these patterns of diversity compare with other freshwater species from the Fouta Djallon highlands and the conservation status of these candidate species are also discussed.     

Single-stranded DNA versus tailed duplex in sequence conversion of lacZα DNA

Abstract

Targeted DNA editing has great potential to cure some genetic diseases; however, the use of artificial nucleases such as CRISPR-Cas9 and TALEN in gene therapy can potentially cause severe side effects due to off-target DNA cleavages. Single-stranded (ss) DNAs and 5'-tailed duplexes (TDs) can achieve target base substitutions when introduced without artificial nucleases into cultured cells and mouse liver. In this study, ss DNA and TD were separately co-introduced into human U2OS cells, together with a target plasmid DNA bearing an inactivated lacZα gene, and the gene correction efficiencies were compared. Unlike the genes examined in previous studies, ss DNA and TD showed similar efficiencies. Therefore, ss DNAs might be as useful as TD for gene correction, depending on the target sequence.     

Potential of transposon-mediated cellular reprogramming towards cell-based therapies

Induced pluripotent stem(iPS) cells present a seminal discovery in cell biology and promise to support innovative treatments of so far incurable diseases. To translate i PS technology into clinical trials, the safety and stability of these reprogrammed cells needs to be shown. In recent years, different non-viral transposon systems have been developed for the induction of cellular pluripotency, and for the directed differentiation into desired cell types. In this review, we summarize the current state of the art of different transposon systems in i PS-based cell therapies.     

purpl: program for marker correction on multicross designs made of Pure Lines

In plants, molecular analyses carried out on breeding populations are becoming increasingly popular. Here we introduce a new software tool, purpl , which was designed to follow and correct the inheritance of codominant molecular markers in such populations in which the level of difficulties in marker notation and the uncertainty of pedigrees are generally high. Based on a five‐step algorithm and on the computation of intuitive probability scores, purpl corrects many different possible sources of bias by extracting the more likely information in the parent and progeny files (initially linked by putative pedigrees), and rebuilds possible missing information. PurPL and the user's guide are available at http://www.clermont.inra.fr/umr‐asp/purpl/     

Approximating Exact Probabilities by χ2 and Continuity-Corrected χ2 in 2×2 Tables

Computations have been performed to find an adequate definition of exact two-sided probabilities in 2times2 contingency tables. It turns out, that both uncorrected χ² and Yates' correction for continuity give only unsatisfactory approximations to the exact probabilities of the hypergeometric distribution. The latter are therefore recommended for general use.     

The effect of scatter correction and radius of rotation on semiquantitative measurements in SPECT 123I-FP-CIT imaging. A phantom study

PurposeThe high energy emissions of ¹²³I and the suboptimal radius of rotation affect the semiquantitative measurements performed during ¹²³I-FP-CIT tomographic imaging. An in-house extra low cost striatum phantom with brain and striatum compartments was constructed and was used to study the effects of Triple Energy Window scatter correction (TEW-SC) and radius of rotation on the Specific Binding Ratio (SBR) measurements.Materials and methodsThe phantom compartments were filled with radioactive ¹²³I solutions with varying concentrations, in a series of experiments. Tomographic images were acquired at six different radii of rotation, with and without TEW-SC and the SBRs were calculated using appropriate regions of interest, as in clinical imaging.ResultsSBRs decreased with increasing radius of rotation in both non-SC and TEW-SC images, the decrease being more pronounced in the latter. The application of TEW-SC increases SBR values by 40% on average. A maximum %Recovery of 42.7% of the true SBR value was achieved in the non-SC images, which increased to 64.6% after TEW-SC. Appropriate correction factors (CF) were calculated in order to make the SBR values independent on the radius of rotation, which could be used to correct SBR values obtained from tomographic acquisitions with suboptimal radius of rotation.ConclusionThe use of appropriate CF can provide more consistent SBR values and a more meaningful comparison between SBRs calculated from images acquired at different radii of rotation.