The line structure of balanced ternary designs with block size three, index three and rho(2) = 1, 2

In this paper necessary and sufficient conditions for a vector to be the fine structure of a balanced ternary design with block size 3, index 3 and rho(2) = 1 and 2 are determined with one unresolved case.

Eye design and color signaling in a stomatopod crustacean Gonodactylus smithii

Many species of stomatopod crustaceans have multiple spectral classes of photoreceptors in their retinas. Behavioral evidence also indicates that stomatopods are capable of discriminating objects by their spectral differences alone, Most animals use only two to four different types of photoreceptors in their color vision systems, typically with broad sensitivity functions, but the stomatopods apparently include eight or more narrowband photoreceptor classes for color recognition. It is also known that stomatopods use several colored body regions in social interactions. To examine why stomatopods may be so 'concerned' with color, we measured the absorption spectra of visual pigments and intrarhabdomal filters, and the reflectance spectra from different parts of the bodies of several individuals of the gonodactyloid stomatopod species, Gonodactylus smithii. We then applied a model of multiple dichromatic channels for color encoding to examine whether the finely tuned color vision was specifically co-evolved with their complex color signals. Although the eye design of stomatopods seems suitable for detecting color signals of their own, the detection of color signals from other animals, such as reef fishes, can be enhanced as well. Color vision in G. smithii is therefore not exclusively adapted to detect its own color signals, but the spectral tuning of some photoreceptors (e.g. midband Rows 2 and 3) enhances the contrast of certain color signals to a large enough degree to make co-evolution between color vision and these rather specific color signals likely. Copyright (C) 2000 S. Karger AG, Basel.

Why do non-color words interfere with color naming?

In the non-color-word Stroop task, university students' response latencies were longer for low-frequency than for higher frequency target words. Visual identity primes facilitated color naming in groups reading the prime silently or processing it semantically (Experiment 1) but did not when participants generated a rhyme of the prime (Experiment 3). With auditory identity primes, generating an associate or a rhyme of the prime produced interference (Experiments 2 and 3). Color-naming latencies were longer for nonwords than for words (Experiment 4). There was a small long-term repetition benefit in color naming for low-frequency words that had been presented in the lexical decision task (Experiment 5). Facilitation of word recognition speeds color naming except when phonological activation of the base word increases response competition.

Identification of cellular changes associated with increased production of human growth hormone in a recombinant Chinese hamster ovary cell line

A proteomics approach was used to identify the proteins potentially implicated in the cellular response concomitant with elevated production levels of human growth hormone in a recombinant Chinese hamster ovary (CHO) cell line following exposure to 0.5 mM butyrate and 80 muM zinc sulphate in the production media. This involved incorporation of two-dimensional (2-D) gel electrophoresis and protein identification by a combination of N-terminal sequencing, matrix-assisted laser desorption/ionisation-time of flight mass spectrometry, amino acid analysis and cross species database matching. From these identifications a CHO 2-D reference,map and annotated database have been established. Metabolic labelling and subsequent autoradiography showed the induction of a number of cellular proteins in response to the media additives butyrate and zinc sulphate. These were identified as GRP75, enolase and thioredoxin. The chaperone proteins GRP78, HSP90, GRP94 and HSP70 were not up-regulated under these conditions.

Neuroarchitecture of the color and polarization vision system of the stomatopod haptosquilla

The apposition compound eyes of stomatopod crustaceans contain a morphologically distinct eye region specialized for color and polarization vision, called the mid-band. In two stomatopod superfamilies, the mid-band is constructed from six rows of enlarged ommatidia containing multiple photoreceptor classes for spectral and polarization vision. The aim of this study was to begin to analyze the underlying neuroarchitecture, the design of which might reveal clues how the visual system interprets and communicates to deeper levels of the brain the multiple channels of information supplied by the retina. Reduced silver methods were used to investigate the axon pathways from different retinal regions to the lamina ganglionaris and from there to the medulla externa, the medulla interna, and the medulla terminalis. A swollen band of neuropil-here termed the accessory lobe-projects across the equator of. the lamina ganglionaris, the medulla externa, and the medulla interna and represents, structurally, the retina's mid-band. Serial semithin and ultrathin resin sections were used to reconstruct the projection of photoreceptor axons from the retina to the lamina ganglionaris. The eight axons originating from one ommatidium project to the same lamina cartridge. Seven short visual fibers end at two distinct levels in each lamina cartridge, thus geometrically separating the two channels of polarization and spectral information. The eighth visual fiber runs axially through the cartridge and terminates in the medulla externa. We conclude that spatial, color, and polarization information is divided into three parallel data streams from the retina to the central nervous system. (C) 2003 Wiley-Liss, Inc.

Process development for a recombinant Chinese Hamster Ovary (CHO) cell line utilizing a metal induced and amplified metallothionein expression system

The suspension Chinese Hamster Ovary cell line, 13-10-302, utilizing the metallothionein (MT) expression system producing recombinant human growth hormone (hGH) was studied in a serum-free and cadmium-free medium at different fermentation scales and modes of operation. Initial experiments were carried out to optimize the concentration of metal addition to induce the MT promoter. Subsequently, the cultivation of the 13-10-302 cell line was scaled up from spinner flasks into bioreactors, and the cultivation duration was extended with fed-batch and perfusion strategies utilizing 180 muM zinc to induce the promoter controlling expression of recombinant hGH. It was shown that a fed-batch process could increase the maximum cell numbers twofold, from 3.3 to 6.3 x 10(6) cell/mL, over those obtained in normal batch fermentations, and this coupled with extended fermentation times resulted in a fourfold increase in final hGH titer, from 135 +/- 15 to 670 +/- 70 mg/L at a specific productivity q(hGH) value of 12 pg cell(-1)d(-1). The addition of sodium butyrate increased the specific productivity of hGH in cells to a value of approximately 48 pg cell(-1)d(-1), resulting in a final hGH titer of over a gram per liter during fed-batch runs. A BioSep acoustic cell recycler was used to retain the cells in the bioreactor during perfusion operation. It was necessary to maintain the specific feeding rates (SFR) above a value of 0.2 vvd/(10(6) cell/mL) to maintain the viability and productivity of the 13-10-302 cells; under these conditions the viable cell number increased to over 107 cell/mL and resulted in a volumetric productivity of over 120 mg(hGH) L(-1)d(-1). Process development described in this work demonstrates cultivation at various scales and sustained high levels of productivity under cadmium free condition in a CHO cell line utilizing an inducible metallothionein expression system. (C) 2004 Wiley Periodicals, Inc.

The 2.0 angstrom crystal structure of a pocilloporin at pH 3.5: The structural basis for the linkage between color transition and halide binding

The pocilloporin Rtms5 and an engineered variant Rtms5(H146S) undergo distinct color transitions (from blue to red to yellow to colorless) in a pH-dependent manner. pK(a) values of 4.1 and 3.2 were determined for the blue (absorption lambda(max), 590 nm) to yellow (absorption lambda(max), similar to 453 nm) transitions of Rtms5 and Rtms5H(146). The pK(a) for the blue-yellow transition of Rtms5H(146S) increased by 1.4 U in the presence of 0.1 M KI, whereas the pK(a) for the same transition of Rtms5 was relatively insensitive to added halides. To understand the structural basis for these observations, we have determined to 2.0 A resolution the crystal structure of a yellow form of Rtms5(H146S) at pH 3.5 in the presence of iodide. Iodide was found occupying a pocket in the structure with a pH of 3.5, forming van der Waals contacts with the tyrosyl moiety of the chromophore. Elsewhere, it was determined that this pocket is occupied by a water molecule in the Rtms5(H141S) structure (pH 8.0) and by the side chain of histidine 146 in the wild-type Rtms5 structure. Collectively, our data provide an explanation for the observed linkage between color transitions for Rtms5(H146S) and binding to halides.

Mode of action of back-line application of spinosad, a non-systemic parasiticide, on sheep

Spinosad, applied as a jetting solution or dip is an efficacious, non-systemic treatment for the control of Bovicola ovis in sheep. This paper describes the effect of back-line treatment width and group housing of animals on the efficacy of spinosad for the control of lice. A 0.4 mg/kg liveweight dose was found to be the suboptimal dose of spinosad for the control of body lice in a dose titration study and was used to investigate application and housing effects in a second study. Lousy Merino sheep were treated with either a narrow 3-cm application of spinosad or with a wider 25-cm swathe. After treatment they were either kept alone or in groups of 6 sheep per pen. Lice were counted at day 0 and every 14 days to 70 days after treatment before estimation of the percentage of lice control and analysis of treatment effects. A much higher percentage of lice control was achieved with 0.4 mg/kg in the second study than in the first, possibly because of differences in formulation used. The wider application width gave significantly higher (P < 0.05) control of lice than the narrow application when sheep were either housed alone or in groups up to day 42 post-treatment. Greater control of lice was seen in group-housed sheep compared with sheep housed individually (P < 0.05) up to day 70. Using broader application widths combined with holding the animals together after treatment with pour-on formulations may optimise the delivery and efficacy of ectoparasiticides for livestock.

Processing of mutated human proinsulin to mature insulin in the non-endocrine cell line, CHO

Heterologous genes encoding proproteins, including proinsulin, generally produce mature protein when expressed in endocrine cells while unprocessed or partially processed protein is produced in non-endocrine cells. Proproteins, which are normally processed in the regulated pathway restricted to endocrine cells, do not always contain the recognition sequence for cleavage by furin, the endoprotease specific to the constitutive pathway, the principal protein processing pathway in non-endocrine cells. Human proinsulin consists of B-Chain-C-peptide-A-Chain and cleavage at the B/C and C/A junctions is required for processing. The B/C, but not the C/A junction, is recognised and cleaved in the constitutive pathway. We expressed a human proinsulin and a mutated proinsulin gene with an engineered furin recognition sequence at the C/A junction and compared the processing efficiency of the mutant and native proinsulin in Chinese Hamster Ovary cells. The processing efficiency of the mutant proinsulin was 56% relative to 0.7% for native proinsulin. However, despite similar levels of mRNA being expressed in both cell lines, the absolute levels of immunoreactive insulin, normalized against mRNA levels, were 18-fold lower in the mutant proinsulin-expressing cells. As a result, there was only a marginal increase in absolute levels of insulin produced by these cells. This unexpected finding may result from preferential degradation of insulin in non-endocrine cells which lack the protection offered by the secretory granules found in endocrine cells.

Super-CHO - A cell line capable of autocrine growth under fully defined protein-free conditions

Chinese Hamster Ovary (CHO) cells are widely used for the large scale production of recombinant biopharmaceuticals. Growth of the CHO-K1 cell line has been demonstrated in serum-free medium containing insulin, transferrin and selenium. In an attempt to get autocrine growth in protein-free medium, DNA coding for insulin and transferrin production was transfected into CHO-K1 cells. Transferrin was expressed well, with clones secreting approximately 1000 ng/10(6)cells/24h. Insulin was poorly expressed, with rates peaking at 5 ng/10(6)cells/24h. Characterisation of the secreted insulin indicated that the CHO cells were incompletely processing the insulin molecule. Site-directed mutagenesis was used to introduce a furin (prohormone converting enzyme) recognition sequence into the insulin molecule, allowing the production of active insulin. However, the levels were still too low to support autocrine growth. Further investigations revealed insulin degrading activity (presumably due to the presence of insulin degrading enzymes) in the cytoplasm of CHO cells. To overcome these problems insulin-like growth factor I (instead of insulin) was transfected into the cells. IGF-1 was completely processed and expressed at rates greater than 500 ng/10(6)cells/24h. In this paper we report autonomous growth of the transfected CHO-K1 cell line expressing transferrin and IGF-1 in protein-free medium without the addition of exogenous growth factors. Growth rates and final cell densities of these cells were identical to that of the parent cell line CHO-K1 growing in insulin, transferrin, and selenium supplemented serum-free media.

Substrate-bound carbohydrates stimulate signal transduction and neurite outgrowth in an olfactory neuron cell line

SUBPOPULATIONS of olfactory receptor neurons, which are dispersed throughout the olfactory neuroepithelium, express specific cell surface carbohydrates and project to discrete regions of the olfactory bulb. Cell surface carbohydrates such as N-acetyl-lactosamine have been postulated to mediate sorting and selective fasciculation of discrete axon subpopulations during development of the olfactory pathway. Substrate-bound N-acetyl-lactosamine promotes neurite outgrowth by both clonal olfactory receptor neuron cell lines and olfactory receptor neurons in vitro, indicating that cell surface carbohydrates may be ligands for receptor-mediated stimulation of axon growth in vivo. In the present study, the role of transmembrane signaling in N-acetyl-lactosamine-stimulated neurite outgrowth was examined in the clonal olfactory neuron cell line 4.4.2. Substrate-bound N-acetyl-lactosamine stimulated neurite outgrowth which was specifically inhibited by antagonists to N- and L-type calcium channels and to tyrosine kinase phosphorylation. These results indicate that N-acetyl-lactosamine can evoke transmembrane receptor-mediated responses capable of influencing neurite outgrowth.