稻属叶表皮结构特征及其系统学意义

本文对稻属Oryza L. 23种植物叶片表皮的结构特征进行了观察和研究,结果表明:叶表皮的某 些性状,如在叶片脉带之间长细胞中乳突的大小和分布以及叶表皮气孔器上小乳突的数目和着生位置 在稻属的各种之间有着一定的变异规律,这在稻属各种的分类和其系统关系的研究中有一定的价值。 综合这些性状的变异特征,按照叶片下表皮脉间长细胞中乳突的大小和分布特征以及气孔器中小乳突 的数目和着生位置可将稻属这23个物种分为3组。第一组包括长颖野稻、马来野稻、疣粒野稻和颗粒 野稻,这些种的叶表皮脉间长细胞中没有大乳突和中乳突,仅偶见极稀疏分布的小乳突,气孔器中均无 小乳突。第二组包括短药野稻、二倍体和四倍体药用野稻、小粒野稻、紧穗野稻、斑点野稻、阔叶野稻、高 株野稻、大颖野稻、根茎野稻和澳洲野稻,这些种的叶表皮脉间长细胞中通常没有大、中乳突,但密布小 乳突,且大多数种的气孔器保卫细胞的近两端各有2个小乳突。第三组包括栽培稻、一年生普通野稻、 多年生普通野稻、长雄蕊野稻、展颖野稻、南方野稻、矮舌野稻、非洲栽培稻和希来特野稻,这些种的叶 表皮脉间的长细胞中常有大乳突、中乳突和小乳突,而气孔器保卫细胞的近两端各有2个明显的小乳 突,并同时常在气孔器副卫细胞的近内缘还有2～4个小乳突。     

Dornyei二语学习动机框架的研究与应用

动机是影响学习成效的一个重要因素,因此动机研究也是外语教学研究最重要的课题之一。几十年来,在研究过程中涌现出的各种动机理论和动机框架对我国的英语教学改革影响至深。本文拟从介绍Dornyei的二语动机框架着手,分析其三层面动机因素对我国大学英语教学改革的启发。     

Do low-skilled workers gain from high-tech employment growth? High-technology multipliers,employment and wages in Britain

Do low-skilled workers benefit from the growth of high-technology industries in their local economy? Policymakers invest considerable resources in attracting and developing innovative, high-tech industries, but there is relatively little evidence on the distribution of the benefits. This paper investigates the labour market impact of high-tech growth on low and mid-skilled workers, using data on UK local labour markets from 2009–2015. It shows that high-tech industries – either STEM-intensive ‘high-tech’ or digital economy – have a positive jobs multiplier, with each 10 new high-tech jobs creating around 7 local non-tradeable service jobs, around 6 of which go to low-skilled workers. Employment rates for mid-skilled workers do not increase, but they benefit from higher wages. Yet while low-skilled workers gain from higher employment rates, the jobs are often poorly paid service work, so average wages fall, particularly when increased housing costs are considered.     

The anatomy of a troll? Patent licensing business models in the light of patent reassignment data

We examine patent licensing business models of non-practicing entities that generate revenue by selling, licensing, or litigating patents. They may also pursue R&D activities, invent new technologies, or provide services to inventors or product companies. We describe their business models and patent market behavior and then compare their litigation strategies against product companies using a matched sample of highly comparable patents. The main differences among patent licensing firms stem from their technological capabilities, patent portfolio sizes, and external relationships. We find that licensing firms with technological capabilities often pursue litigation until decision and engage in forum shopping. In contrast, litigation incidence, parties involved, and outcomes are primarily determined by patent characteristics, not entity types. Licensing business models drive the acquisition of certain types of patents that influence the outcomes of the patent system. We argue that patent policy should strengthen mechanisms to discover invention quality rather than focus on the amount of litigation or types of entities.     

Electricity (de)regulation and innovation

In this paper we study the effect of deregulation on innovation in the electricity sector using a sample of 31 OECD countries. Exploiting sharp reductions in the level of product market regulation, explicitly linked to changes in the legal framework, we perform a difference-in-difference analysis by matching data retrieved from the OECD International Regulation, OECD Patent Grants, and UN World Development Indicators databases. Our main findings suggest that a decrease in regulation intensity, following a significant reform, has a negative impact on patents (granted by the European Patent Office). This impact appears to be mainly due to the degree of market contestability. Finally, we find evidence of an inverted U-shaped relationship between regulation and innovation. This may imply that the effect of deregulation on innovation depends on the strength of the deregulatory process.     

“In Praise of Wool”: The development of partition chromatography and its under-appreciated impact on molecular biology

The invention of partition chromatography by the biochemists Archer Martin and Richard Synge in 1941 offered crucial insights into the structure and function of DNA, insights at least as important as those from X-ray crystallography. Even so, the role that partition chromatography played in molecular biological studies is far less well known. Using new archival material, this article describes the origins of Martin and Synge’s work, arguing that their achievement was far more than a new technical innovation; it went on to have a profound impact on the development of molecular biology to an extent that scholars have insufficiently appreciated.     

The comparison of the three assays for determination of fecal calprotectin in inflammatory bowel disease

IntroductionFecal calprotectin is a biomarker for monitoring inflammatory bowel disease (IBD) activity. Our aim, therefore, was to evaluate two new assays, the point of care test Quantum Blue and the Liaison Calprotectin with respect to the Calprest, commonly used assay, and to determine their performance for IBD diagnosis.Materials and methodsWe included 73 prospective patients with IBD. Fecal calprotectin was measured and analysed with the routine Calprest assay and two recently introduced assays, the Quantum Blue and the Liaison Calprotectin. Furthermore, we compared the results by Bland and Altman analysis, and Passing-Bablok regression.ResultsWe observed no difference in median calprotectin values obtained by the Calprest (94.6 µg/g, 95%CI 66.5 to 166.1) and Liaison assay (101.0 µg/g, 95%CI 48.1 to 180.1) whereas significantly higher concentrations were obtained with the Quantum Blue assay (240.0 µg/g, 95%CI 119.9 to 353.2). The mean absolute and relative difference between the Calprest and Quantum Blue methods was statistically significant (- 162.3 µg/g and
- 143.1%). Mean absolute difference between the Calprest and Liaison calprotectin methods was positive (2.2 µg/g). The agreement between assays revealed that Quantum Blue and Calprest have fair agreement with Kappa coefficient of 0.38 (95%CI 0.26 to 0.51). Liaison Calprotectin and Calprest revealed moderate agreement with a weak Kappa coefficient of 0.47 (95%CI 0.32 to 0.62).ConclusionClinicians should be aware of these differences between the assays and avoid comparison of their respective results.     

The sidestep cutting manoeuvre requires exertion of lumbosacral lateral flexion torque to avoid excessive pelvic obliquity

During sidestep cutting, the pelvis is supported only on one side; this affects the athlete’s posture. This study investigated the mechanism to avoid excessive pelvic obliquity during sidestep cutting. Ten physically active men performed sidestep cutting with maximal effort, and we captured the kinematics and kinetics with force platforms and an eight-camera motion capture system. Our results indicated that the stance hip exerted little abduction torque; however, lumbosacral lateral flexion torque was exerted towards the free-leg side (peak value: 3.39 ± 0.91 N m/kg). Although bilateral hip joint forces acted to drop the free-leg side of the pelvis, the net torque around pelvic elevation/drop axis was nearly zero during the entire stance phase and the change in the angular momentum around the pelvic elevation/drop axis from touchdown to toe-off was negligible (?0.004 ± 0.003 N m s/kg). The integrated components of lateral flexor for elevating the free-leg side of the pelvis (0.220 ± 0.072 N m s/kg) were significantly larger than any other integrated components, which were all negligible (<0.010 N m s/kg). Thus, sidestep cutting requires the lumbosacral lateral flexion torque exertion to neutralise the passive action that drops the free-leg side of the pelvis.     

马齿苋营养成分分析与抗氧化性研究

目的：按新的国家标准对药食两用植物马齿苋的营养成分进行测定,并对其在体外对自由基的清除作用进行初步研究。方法：粗纤维、淀粉、还原糖、脂肪分别按GB/T5009.10-2003、GB/T5009.9-2003、GB/T5009.3-2003、GB/T5009.6-2003方法测定。对不同的提取部位用邻苯三酚自氧化法和Fenton法测定对氧自由基与羟自由基的清除作用。结果：马齿苋以干品计,粗纤维、淀粉、还原糖、脂肪含量分别为21.3%、4.6%（酶法测定）、3%、1.9%（直接酸水解法）。其水提取部位在一定范围内有较强的作用。结论：马齿苋是具有较高营养价值的食用植物,有一定的抗氧化活性,有较高的开发价值。