On a heuristic point of view concerning the optical activity

Motivated by a recent finding that Fresnel's phenomenological description of the optical activity in the chiral medium is not self-consistent, we conduct a thorough investigation into the nature of the polarization of a plane light wave. We demonstrate that the polarization of light is the reflection of one of its quantum-mechanical properties, called the quasi-spin. Unexpectedly, the quasi-spin is not an observable with respect to the laboratory coordinate system. Instead, it is with respect to the momentum-dependent local coordinate system. The representative operators for the quasi-spin are the Pauli matrices. The wavefunction is the Jones vector. In order to completely determine a state of polarization, two different kinds of degrees of freedom are needed. One is the degrees of freedom to characterize the state of quasi-spin. They are the Stokes parameters, the expectation values of the Pauli matrices in the state described by the Jones vector. The other is the degrees of freedom to specify the local coordinate system, including the propagation direction and an angle of rotation about it. Accordingly, there are two independent mechanisms to change the state of polarization. One is to change the state of quasi-spin in a fixed local coordinate system. This is the traditional mechanism that can be expressed as an SU(2) rotation of the Jones vector. The other is to change the local coordinate system with the state of quasi-spin remaining fixed in it. At last, we show that it is the newly-identified mechanism that accounts for the optical activity.Comment: 24 page

Stokes parameters alone cannot completely characterize the polarization of plane light waves

It was generally assumed that the Stokes parameters are complete characterization for the state of polarization of a plane light wave so that their counterparts in quantum optics, called the Stokes operators, represent the polarization of photons. Here we show, through analyzing the properties of polarized plane waves in an optically active medium, that the Stokes parameters are not able to completely characterize the state of polarization of a plane wave. The key point is that only when a plane wave is expanded in terms of the orthogonal base modes, which are physically meaningful, can the two expansion coefficients make up the Jones vector. Taking this into consideration, we demonstrate that the Stokes parameters of any elliptically polarized wave in an isotropic chiral medium, determined solely by its Jones vector, are transmitted unchanged. They are not able to reflect the rotation of its polarization ellipse along with the propagation. The relationship of the Stokes parameters with the polarization of light needs further investigation.Comment: 13 page

Long-range dependence and multifractality of ship flow sequences in container ports : A comparison of Shanghai, Singapore, and Rotterdam

The prediction of ship traffic flow is an important fundamental preparation for layout and design of ports as well as management of ship navigation. However, until now, the temporal characteristics and accurate prediction of ship flow sequence in port are rarely studied. Therefore, in this study, we investigated the presence of long-range dependence in container ship flow sequences using the Multifractal Detrended Fluctuation Analysis (MF-DFA). We considered three representative container ports in the world—including Shanghai, Singapore, and Rotterdam container ports—as the study sample, from 1 January 2013 to 31 December 2017. Empirical results suggested that the ship flow sequences are deviated from normal distribution, and the sequences with different time scales exhibited varying degrees of long-range dependence. Furthermore, the ship flow sequences possessed a multifractal nature, where the larger the time scale of ship flow time series, the stronger the multifractal characteristics are. The weekly ship flow sequence in the port of Singapore owned the highest degree of multifractality. Furthermore, the multifractality presented in the ship flow sequences of container ports are due to the correlation properties as well as the probability density function of the ship flow sequences. The study outlines the importance of adopting these features for an accurate modeling and prediction for maritime ship flow series

Effect of pinocembrin pre-treatment on expressions of Cx43 protein and claudin 1 in myocardial ischemia cardiomyocytes of arrhythmic rats

Purpose: To investigate the effects of pinocembrin on ventricular rhythm and the expression of cardiomyocyte ligament junction protein (Cx43) and claudin 1 (ZO-1) in ischemia/reperfusion (I/R) rats.Methods: Ischemia/reperfusion (I/R) model rats (n = 15) were divided into 5 groups: IR group, control group, and 3 pinocembrin groups (3, 10 and 30 mg/kg). The serum levels of creatine kinase-MB isoenzyme (CK-MB) and troponin I (cTnI) were measured by enzyme-linked immunosorbent assay (ELISA). Changes in myocardial tissue were detected by H & E staining, while mRNA and protein levels of Cx43, ZO-1 and Kir2.1 were measured by reverse transcriotion-polymerase chain reaction (RT-PCR) and Western blotting, respectively.Results: In pinocembrin groups, heart rate (HR), mean arterial pressure (MAP) and rate-pressure product (RPP) levels were significantly higher compared with IR group (p < 0.05). Moreover, the extent of arrhythmia and the levels of CK-MB and cTnI in pinocembrin groups were lower relative to IR group, while Na+-K+-ATPase and Ca2+-Mg2+-ATPase activities, as well as Cx43 mRNA, ZO-1 mRNA, and protein levels of Cx43, ZO-1 and Kir2.1 were significantly higher than the corresponding values for IR group (p < 0.05).Conclusion: These results suggest that pinocembrin reduces ventricular arrhythmias in I/R rats by upregulation of expressions of Cx43, ZO-1 and Kir21, and inhibition of re-distribution of ZO-1 and Cx43. These findings provide the basis for the clinical application of pinocembrin in the treatment of arrhythmia.Keywords: Pinocembrin, Ventricular arrhythmia, Ligament junction protein, Recombinant human Kir2.1 protein, Arterial pressure, Protein levels, Claudin, Cardiomyocyt

Impacts of recent cultivation on genetic diversity pattern of a medicinal plant, Scutellaria baicalensis (Lamiaceae)

<p>Abstract</p> <p>Background</p> <p>Cultivation of medicinal plants is not only a means for meeting current and future demands for large volume production of plant-based drug and herbal remedies, but also a means of relieving harvest pressure on wild populations. <it>Scutellaria baicalensis </it>Georgi (Huang-qin or Chinese skullcap) is a very important medicinal plant in China. Over the past several decades, wild resource of this species has suffered rapid declines and large-scale cultivation was initiated to meet the increasing demand for its root. However, the genetic impacts of recent cultivation on <it>S. baicalensis </it>have never been evaluated. In this study, the genetic diversity and genetic structure of 28 wild and 22 cultivated populations were estimated using three polymorphic chloroplast fragments. The objectives of this study are to provide baseline data for preserving genetic resource of <it>S. baicalensis </it>and to evaluate the genetic impacts of recent cultivation on medicinal plants, which may be instructive to future cultivation projects of traditional Chinese medicinal plants.</p> <p>Results</p> <p>Thirty-two haplotypes of <it>S. baicalensis </it>(HapA-Y and Hap1-7) were identified when three chloroplast spacers were combined. These haplotypes constituted a shallow gene tree without obvious clusters for cultivated populations, suggesting multiple origins of cultivated <it>S. baicalensis</it>. Cultivated populations (<it>h</it>_T= 0.832) maintained comparable genetic variation with wild populations (<it>h</it>_T= 0.888), indicating a slight genetic bottleneck due to multiple origins of cultivation. However, a substantial amount of rare alleles (10 out of 25 haplotypes within wild populations) lost during the course of <it>S. baicalensis </it>cultivation. The genetic differentiation for cultivated group (<it>G</it>_ST= 0.220) was significantly lower than that of wild group (<it>G</it>_ST= 0.701). Isolation by distance analysis showed that the effect of geographical isolation on genetic structure was significant in wild populations (<it>r </it>= 0.4346, <it>P </it>< 0.0010), but not in cultivated populations (<it>r = </it>0.0599, <it>P </it>= 0.2710). These genetic distribution patterns suggest that a transient cultivation history and the extensive seed change among different geographical areas during the course of <it>S. baicalensis </it>cultivation.</p> <p>Conclusions</p> <p>Although cultivated <it>S. baicalensis </it>maintains comparable genetic diversity relative to wild populations, recent cultivation has still imposed profound impacts on genetic diversity patterns of the cultivated <it>S. baicalensis </it>populations, i.e., the loss of rare alleles and homogenization of cultivated populations. This study suggests that conservation-by-cultivation is an effective means for protecting genetic resources of <it>S. baicalensis</it>, however, the wild resources still need to be protected <it>in situ </it>and the evolutionary consequences of extensive seed exchange mediated by human being should be monitored carefully.</p

Transcriptomic Response of Wolf Spider, \u3cem\u3ePardosa pseudoannulata\u3c/em\u3e, to Transgenic Rice Expressing \u3cem\u3eBacillus thuringiensis\u3c/em\u3e Cry1Ab Protein

Background: Bacillum thuringiensis (Bt) toxin produced in Cry1-expressing genetically modified rice (Bt rice) is highly effective to control lepidopteran pests, which reduces the needs for synthetic insecticides. Non-target organisms can be exposed to Bt toxins through direct feeding or trophic interactions in the field. The wolf spider Pardosa pseudoannulata, one of the dominant predators in South China, plays a crucial role in the rice agroecosystem. In this study, we investigated transcriptome responses of the 5th instar spiders fed on preys maintained on Bt- and non-Bt rice. Results: Comparative transcriptome analysis resulted in 136 differentially expressed genes (DEGs) between spiderlings preying upon N. lugens fed on Bt- and non-Bt rice (Bt- and non-Bt spiderlings). Functional analysis indicated a potential impact of Bttoxin on the formation of new cuticles during molting. GO and KEGG enrichment analyses suggested that GO terms associated with chitin or cuticle, including “chitin binding”, “chitin metabolic process”, “chitin synthase activity”, “cuticle chitin biosynthetic process”, “cuticle hydrocarbon biosynthetic process”, and “structural constituent of cuticle”, and an array of amino acid metabolic pathways, including “alanine, asparatate and glutamate metabolism”, “glycine, serine and theronine metabolism”, “cysteine and methionine metabolism”, “tyrosine metabolism”, “phenylalanine metabolism and phenylalanine”, and “tyrosine and tryptophan biosynthesis” were significantly influenced in response to Cry1Ab. Conclusions: The Cry1Ab may have a negative impact on the formation of new cuticles during molting, which is contributed to the delayed development of spiderlings. To validate these transcriptomic responses, further examination at the translational level will be warranted

Transcriptomic Response of Wolf Spider, \u3cem\u3ePardosa pseudoannulata\u3c/em\u3e, to Transgenic Rice Expressing \u3cem\u3eBacillus thuringiensis\u3c/em\u3e Cry1Ab Protein

Background: Bacillum thuringiensis (Bt) toxin produced in Cry1-expressing genetically modified rice (Bt rice) is highly effective to control lepidopteran pests, which reduces the needs for synthetic insecticides. Non-target organisms can be exposed to Bt toxins through direct feeding or trophic interactions in the field. The wolf spider Pardosa pseudoannulata, one of the dominant predators in South China, plays a crucial role in the rice agroecosystem. In this study, we investigated transcriptome responses of the 5th instar spiders fed on preys maintained on Bt- and non-Bt rice. Results: Comparative transcriptome analysis resulted in 136 differentially expressed genes (DEGs) between spiderlings preying upon N. lugens fed on Bt- and non-Bt rice (Bt- and non-Bt spiderlings). Functional analysis indicated a potential impact of Bttoxin on the formation of new cuticles during molting. GO and KEGG enrichment analyses suggested that GO terms associated with chitin or cuticle, including “chitin binding”, “chitin metabolic process”, “chitin synthase activity”, “cuticle chitin biosynthetic process”, “cuticle hydrocarbon biosynthetic process”, and “structural constituent of cuticle”, and an array of amino acid metabolic pathways, including “alanine, asparatate and glutamate metabolism”, “glycine, serine and theronine metabolism”, “cysteine and methionine metabolism”, “tyrosine metabolism”, “phenylalanine metabolism and phenylalanine”, and “tyrosine and tryptophan biosynthesis” were significantly influenced in response to Cry1Ab. Conclusions: The Cry1Ab may have a negative impact on the formation of new cuticles during molting, which is contributed to the delayed development of spiderlings. To validate these transcriptomic responses, further examination at the translational level will be warranted

Protein tyrosine kinase 6 is associated with nasopharyngeal carcinoma poor prognosis and metastasis

BACKGROUND: The aim of this study was to analyze the expression of protein tyrosine kinase 6 (PTK6) in nasopharyngeal carcinoma (NPC) samples, and to identify whether PTK6 can serve as a biomarker for the diagnosis and prognosis of NPC. METHODS: We used quantitative RT-PCR and Western blotting analysis to detect mRNA and protein expression of PTK6 in NPC cell lines and immortalized nasopharyngeal epithelial cell lines. 31 NPC and 16 non-tumorous nasopharyngeal mucosa biopsies were collected to detect the difference in the expression of mRNA level of PTK6 by quantitative RT-PCR. We also collected 178 NPC and 10 normal nasopharyngeal epithelial cases with clinical follow-up data to investigate the expression of PTK6 by immunohistochemistry staining (IHC). PTK6 overexpression on cell growth and colony formation ability were measured by the method of cell proliferation assay and colony formation assay. RESULTS: The expression of PTK6 was higher in most of NPC cell lines at both mRNA and protein levels than in immortalized nasopharyngeal epithelial cell lines (NPECs) induced by Bmi-1 (Bmi-1/NPEC1, and Bmi-1/NPEC2). The mRNA level of PTK6 was high in NPC biopsies compared to non-tumorous nasopharyngeal mucosa biopsies. IHC results showed the expression of PTK6 was significantly correlated to tumor size (P<0.001), clinical stage (P<0.001), and metastasis (P=0.016). The patients with high-expression of PTK6 had a significantly poor prognosis compared to those of low-expression (47.8% versus 80.0%, P<0.001), especially in the patients at the advanced stages (42.2% versus 79.1%, P<0.001). Multivariate analysis indicated that the level of PTK6 expression was an independent prognostic factor for the overall survival of patients with NPC (P <0.001). Overexpression of PTK6 in HNE1 cells enhanced the ability of cell proliferation and colony formation. CONCLUSIONS: Our results suggest that high-expression of PTK6 is an independent factor for NPC patients and it might serve as a potential prognostic biomarker for patients with NPC

Identification and Characterization of a Novel Non-Coding RNA Involved in Sperm Maturation

A long and ever-expanding roster of small (∼20–30 nucleotides) RNAs has emerged during the last decade, and most can be subsumed under the three main headings of microRNAs(miRNAs), Piwi-interacting RNAs(piRNAs), and short interferingRNAs(siRNAs). Among the three categories, miRNAs is the most quickly expanded group. The most recent number of identified miRNAs is 16,772 (Sanger miRbase, April 2011). However, there are insufficient publications on their primary forms, and no tissue-specific small RNAs precursors have been reported in the epididymis. Here, we report the identification in rats of an epididymis-specific, chimeric, noncoding RNA that is spliced from two different chromosomes (chromosomes 5 and 19), which we named HongrES2. HongrES2 is a 1.6 kb mRNA-like precursor that gives rise to a new microRNA-like small RNA (mil-HongrES2) in rat epididymis. The generation of mil-HongrES2 is stimulated during epididymitis. An epididymis-specific carboxylesterase named CES7 had 100% cDNA sequence homology at the 3′end with HongrES2 and its protein product could be downregulated by HongrES2 via mil-HongrES2. This was confirmed in vivo by initiating mil-HongrES2 over-expression in rats and observing an effect on sperm capacitation