The use of wavefront encoding to reduce crosstalk in a multicasting fiber telecom switch

A multicasting fiber optic switch employing a liquid crystal on silicon spatial light modulator is used to demonstrate wavefront encoding, a novel technique for crosstalk mitigation. Experimentally we reduce worst case crosstalk by 7.5dB. © 2012 OSA.

Demonstration of a self aligned hybrid silicon-plasmonic waveguide with low loss and nanoscale confinement

We demonstrate self-aligned approach for fabricating hybrid silicon plasmonic waveguide. The demonstrated structure provides nanoscale confinement together with propagation length of 100 microns on chip. Near-field measurements of propagation and coupling loss are presented. ©2011 Optical Society of America.

Depletion of Vipp1 in Synechocystis sp PCC 6803 affects photosynthetic activity before the loss of thylakoid membranes

A vipp1 mutant of Synechocystis sp. PCC 6803 could not be completely segregated under either mixotrophic or heterotrophic conditions. A vipp1 gene with a copper-regulated promoter (P-petE-vipp1) was integrated into a neutral platform in the genome of the merodiploid mutant. The copper-induced expression of P-petE-vipp1 allowed a complete segregation of the vipp1 mutant and observation of the phenotype of Synechocystis 6803 with different levels of vesicle-inducing protein in plastids 1 (Vipp1). When P-petE-vipp1 was turned off by copper deprivation, Synechocystis lost Vipp1 and photosynthetic activity almost simultaneously, and at a later stage, thylakoid membranes and cell viability. The photosystem II (PSII)-mediated electron transfer was much more rapidly reduced than the PSI-mediated electron transfer. By testing a series of concentrations, we found that P-petE-vipp1 cells grown in medium with 0.025 mu M Cu2+ showed no reduction of thylakoid membranes, but greatly reduced photosynthetic activity and viability. These results suggested that in contrast to a previous report, the loss of photosynthetic activity may not have been due to the loss of thylakoid membranes, but may have been caused more directly by the loss of Vipp1 in Synechocystis 6803.

Fridericia dianchiensis sp nov (Enchytraeidae, oligochaeta) from Yunnan Province, China

Fridericia dianchiensis, a new enchytraeid species collected from Yunnan Province, is described here. It is characterized by a combination of the following characters: 1) lateral bundles containing maximum 3 chaetae; 2) esophageal appendages with 3-4 simple, terminal branches; 3) dorsal vessel originating in XX-XXIII; 4) sub-neural glands absent; 5) seminal vesicle large, occupying two segments; 6)clitellum girdle-shaped or gland cells absent between bursal slits and pre-middle ventrally; 7) coelomocytes without refractile vesicles, 8) spermatheca without diverticula and both ampullae broadly united; and 9) long spermathecal ectal duct without gland at the orifice.

High variability of the gvpA-gvpC region in Microcystis

Gas vesicles provide buoyancy to Microcystis and other common cyanobacterial bloom-forming species. gvpA and gvpC are structural genes encoding gas vesicle proteins. Phylogenetic analyses of 10 Microcystis strains/uncultured samples showed that gvpC and each intergenic segment of the gvpA-gvpC region can be divided into two types. The combination of different types of gvpC and intergenic segments is an important factor that diversifies this genomic region. Some Microcystis strains isolated in China possess a 172 to 176 bp sequence tag in the intergenic segment between gvpA and gvpC. The gvpA-gvpC region in Microcystis can be divided into at least 4 classes and more numbers of subclasses. Compared to rbcLX and other regions, the high variability of the gvpA-gvpC region should be more useful in identifying geographical isolates or ecotypes of Microcystis.

Electrical addressing of polymer stabilized hyper-twisted chiral nematic liquid crystals with interdigitated electrodes: Experiment and model

Electro-optic switching in short-pitch polymer stabilized chiral nematic liquid crystals was studied and the relative contributions of flexoelectric and dielectric coupling were investigated: polymer stabilization was found to effectively suppress unwanted textural transitions of the chiral nematic liquid crystal and thereby enhance the electro-optical performance (high optical contrast for visible light, a near ideal optical hysteresis, fast electro-optic response). Test cells were studied that possessed interdigitated electrodes to electrically address the liquid crystal. Based on simulations, a well-fitted phenomenological description of the electro-optic response was derived considering both flexoelectro-optic and Kerr-effect based electro-optic response. © 2014 AIP Publishing LLC.

Intelectin gene from the grass carp Ctenopharyngodon idella: cDNA cloning, tissue expression, and immunohistochemical localization

The cDNA encoding grass carp intelectin was isolated from a head kidney cDNA library, and termed gcIntL. The deduced amino acid sequence of gcIntL consists of 318 amino acids, and about 55% identical and 74% similar to human intelectin, which is a new type of lectin recognizing galactofuranose, and plays a role in the recognition of bacteria-specific components in animal hosts. The gcIntL gene consists of seven exons and six introns, spacing over approximately 3 kb of genomic sequence. Phylogenetic analysis clearly demonstrated that the gcIntL formed a clade with Danio rerio intelectin and 35 kDa serum lectin. By real-time quantitative RT-PCR analysis, gcIntL transcripts were significantly induced in head kidney, trunk kidney, spleen, and intestine from LPS-stimulated fish. RT-PCR and Western blotting analysis demonstrated that the mRNA and protein of gcIntL gene have the same expression pattern, and both were detected in brain, gill, intestine, head kidney, trunk kidney, spleen, and heart. Furthermore, gcIntL protein could be detected in gill, intestine, trunk kidney, head kidney, spleen, heart, and brain including medulla oblongata and optic lobe, as determined by immunohistochemistry. This is the first report of intelectin expression pattern in fish, and of recombinant gcIntL and polyclonal antibody against gcIntL. (c) 2006 Elsevier Ltd. All rights reserved.

Identification of a putative oocyte-specific small nuclear ribonucleoprotein polypeptide C in gibel carp

Previous studies have demonstrated that germinal vesicle of amphibian oocyte contains small nuclear ribonucleoprotein polypeptide C (SNRPC). In this study, a putative member of SNRPC was identified from Carassius auratus gibelio oocyte cDNA library. Its full-length cDNA has an open reading frame of 201 nt for encoding a peptide of 66 an, a short 5'-UTR of 19 nt and a long 3'-UTR of 347 nt including a polyadenylation signal and poly- (A) tail, and the deduced amino acid sequence has 47% identity with the C-terminal of the zebrafish small nuclear ribonucleoprotein polypeptide C. Western blot analysis revealed its oocyte-specific expression. Immunofluorescence localization indicated that its gene product localized to numerous nucleoli within the oocytes and showed dynamic changes with the nucleoli during oocyte maturation. RT-PCR and Western blot analysis further revealed its constant presence in the oocytes and in the embryos until hatching. The data suggested that the newly identified CagOSNRPC might be a nucleolar protein. (c) 2006 Elsevier Inc. All rights reserved.

A taxonomic study of Oconnorella (Enchytraeidae, Oligochaeta) from Changbaishan Mountain, China

We describe three enchytraeid species, including two new species, from Mt. Changbaishan, Jilin Province, northeastern China. Oconnorella cheni sp. nov. is characterized by a simple spermatheca; absence of the oesophageal appendages and seminal vesicle; and nephridia from 6/7, with a distinct funnel and the efferent duct arising from the anterior part of the postseptale. Oconnorella globula sp. nov. is distinguished by a spermatheca with two diverticula; lack of oesophageal appendages and seminal vesicle; and nephridia from 6/7, with distinct funnel and the efferent duct arising from the mid-ventral or posteroventral part of the postseptale. We redescribe Oconnorella changbaishanensis (Xie et al., 2000) from type and live specimens, and amend some characters that cannot be investigated clearly from mounted specimens. We revise the generic diagnosis of Oconnorella.

The first non-mammalian CXCR3 in a teleost fish: Gene and expression in blood cells and central nervous system in the grass carp (Ctenopharyngodon idella)

A novel fish chemokine receptor gene, chemokine (C-X-C motif) receptor 3 (CXCR3)-like was isolated from the grass carp Ctenopharyngodon idella , with its full-length genomic sequence. The cDNA of grass carp CXCR3-like (gcCXCR3-like) consists of 1261 bp with a 49bp 5'-UTR and a 189 bp 3'-UTR. An open reading frame of 1023 bp encodes a 341-amino acid peptide, with seven transmembrane helices. The deduced amino acid sequence showed the same sequence identities (37.8%) with its counterparts in goat and human. The gcCXCR3-like gene consists of two exons, with one intervening intron, spaced over approximately 2 kb of genomic sequence. Phylogenetic analyses clearly demonstrated that the gcCXCR3-like resembles the CXCR3s of other vertebrates. Real-time PCR analysis showed that gcCXCR3-like was expressed in all tested organs except heart and the expression level of gcCXCR3-like was highest in brain. Flow cytometric analyses showed the positive rate of labelled leukocytes from the healthy grass carp was 17.3%, and the labelled leukocytes were divided into three types by cell sorting. Immunohistochemical localization revealed that gcCXCR3-like expressed in whole brain regions including cerebel, diencephalon, medulla oblongata, optic lobe, and rhinencephalon, and that the labelled leukocytes are actually populations of monocyte and/or phagocyte, lymphocyte and the granulocyte. It is considered that fish CXCR expression and their function may need to be investigated in both nervous and immune systems. (c) 2006 Elsevier Ltd. All rights reserved.

Stretchable liquid-crystal blue-phase gels.

Liquid-crystalline polymers are materials of considerable scientific interest and technological value. An important subset of these materials exhibit rubber-like elasticity, combining the optical properties of liquid crystals with the mechanical properties of rubber. Moreover, they exhibit behaviour not seen in either type of material independently, and many of their properties depend crucially on the particular mesophase employed. Such stretchable liquid-crystalline polymers have previously been demonstrated in the nematic, chiral-nematic, and smectic mesophases. Here, we report the fabrication of a stretchable gel of blue phase I, which forms a self-assembled, three-dimensional photonic crystal that remains electro-optically switchable under a moderate applied voltage, and whose optical properties can be manipulated by an applied strain. We also find that, unlike its undistorted counterpart, a mechanically deformed blue phase exhibits a Pockels electro-optic effect, which sets out new theoretical challenges and possibilities for low-voltage electro-optic devices.

Infection and propagation of lymphocystis virus isolated from the cultured flounder Paralichthys olivaceus in grass carp cell lines

The causative agent of lymphocystis disease that frequently occurs in cultured flounder Paralichthys olivaceus in China is lymphocystis virus (LV). In this study, 13 fish cell lines were tested for their susceptibility to LV. Of these, 2 cell lines derived from the freshwater grass carp Ctenopharyngodon idellus proved susceptible to the LV, and 1 cell line, GCO (grass carp ovary), was therefore used to replicate and propagate the virus. An obvious cytopathic effect (CPE) was first observed in cell monolayers at 1 d post-inoculation, and at 3 d this had extended to about 75% of the cell monolayer. However, no further CPE extension was observed after 4 d. Cytopathic characteristics induced by the LV were detected by Giemsa staining and fluorescence microscopic observation with Hoechst 33258 staining. The propagated virus particles were also observed by electron microscopy. Ultrastructure analysis revealed several distinct cellular changes, such as chromatin compaction and margination, vesicle formation, cell-surface convolution, nuclear fragmentation and the occurrence of characteristic 'blebs' and cell fusion. This study provides a detailed report of LV infection and propagation in a freshwater fish cell line, and presents direct electron microscopy evidence for propagation of the virus in infected cells. A possible process by which the CPEs are controlled is suggested.

Isolation of a lethal rhabdovirus from the cultured Chinese sucker Myxocyprinus asiaticus

A rhabdovirus was found to be associated with a lethal hemorrhagic disease in the cultured Chinese sucker Myxocyprinus asiaticus Bleeker. The rhabdovirus was amplified and isolated from the infected GCO, (grass carp ovary) cells. In ultrathin sections of liver cells from the diseased fish, the virus particles exhibited the characteristic bacilliform morphology, and budded through vesicle membranes of the infected cells. The isolated rhabdovirus particles were found to have a bacilliform morphology with 2 rounded ends rather than a typical flat base. The virus particles were measured and ranged in size from 150 to 200 nm in length and 50 to 60 nm in diameter. Most other characteristics, including their size, extensive virus infectivity to fish cell Lines, strong cytopathogenic effects, stability at high temperatures, vesicle formation in infected cells, structure protein electrophoretic patterns and the presence of an RNA genome, very closely resembled those of other fish rhabdoviruses. At present it is not known if this is a novel virus species or if it is an isolate of a known fish rhabdovirus. Until a confirmed identification can be made, we will temporarily refer to this virus as Chinese sucker rhabdovirus (CSRV).

The effect of an electric field on the nonlinear response of InAs/GaAs quantum dots

The refractive nonlinearities of InAs/GaAs quantum dots under a dc electric field at photon energies above its band gap energy have been studied using the reflection Z-scan technique. The effect of the dc electric field on the nonlinear response of InAs/GaAs quantum dots showed similar linear and quadratic electro-optic effects as in the linear response regime at low fields. This implies that the electro-optic effect in the nonlinear regime is analogous to the response in the linear regime for semiconductor quantum dots. Our experimental results show the potential for voltage tunability in InAs quantum dot-based nonlinear electro-optic devices.

Effects of external magnetic field on the effective g factor of (Ga,Mn)As

With the help of time resolved magneto-optic Kerr rotation measurements, the optically induced spin precession in heavily doped diluted magnetic semiconductor Ga0.937Mn0.063 As was observed. It was found that the effective g factor increases with increasing magnetic field, which is attributed to the magnetic-field-induced increase of the density of the non-localized holes. Those free holes will couple with the localized magnetic ions by p-d interactions, leading to the formation of spontaneous magnetization in Ga0.937Mn0.063As, which in turn to the enhancement of the effective g factor.