Isolation of an acetyl-CoA synthetase gene (ZbACS2) from Zygosaccharomyces bailii

A gene homologous to Saccharomyces cerevisiae ACS genes, coding for acetyl-CoA synthetase, has been cloned from the yeast Zygosaccharomyces bailii ISA 1307, by using reverse genetic approaches. A probe obtained by PCR amplification from Z. bailii DNA, using primers derived from two conserved regions of yeast ACS proteins, RIGAIHSVVF (ScAcs1p; 210-219) and RVDDVVNVSG (ScAcs1p; 574-583), was used for screening a Z. bailii genomic library. Nine clones with partially overlapping inserts were isolated. The sequenced DNA fragment contains a complete ORF of 2027 bp (ZbACS2) and the deduced polypeptide shares significant homologies with the products of ACS2 genes from S. cerevisiae and Kluyveromyces lactis (81% and 82% identity and 84% and 89% similarity, respectively). Phylogenetic analysis shows that the sequence of Zbacs2 is more closely related to the sequences from Acs2 than to those from Acs1 proteins. Moreover, this analysis revealed that the gene duplication producing Acs1 and Acs2 proteins has occurred in the common ancestor of S. cerevisiae, K. lactis, Candida albicans, C. glabrata and Debaryomyces hansenii lineages. Additionally, the cloned gene allowed growth of S. cerevisiae Scacs2 null mutant, in medium containing glucose as the only carbon and energy source, indicating that it encodes a functional acetyl-CoA synthetase. Also, S. cerevisiae cells expressing ZbACS2 have a shorter lag time, in medium containing glucose (2%, w/v) plus acetic acid (0.1-0.35%, v/v). No differences in cell response to acetic acid stress were detected both by specific growth and death rates. The mode of regulation of ZbACS2 appears to be different from ScACS2 and KlACS2, being subject to repression by a glucose pulse in acetic acid-grown cells.     

Enhanced selenium content in buckwheat (<Emphasis Type="Italic">Fagopyrum esculentum</Emphasis> Moench) and pumpkin (<Emphasis Type="Italic">Cucurbita pepo</Emphasis> L.) seeds by foliar fertilisation

The fruit and thin-husked seeds of the pumpkin (Cucurbita pepo L.) and buckwheat grain (Fagopyrum esculentum Moench), both grown in Slovenia, were analysed for selenium (Se) content following foliar application of Se(VI) solution during the period of blooming. Samples were digested by a H₂SO₄-HNO₃-H₂O₂-V₂O₅ mixture and Se determined, based on hydride generation atomic fluorescence spectrometry. The whole procedure from weighing to measuring was carried out in the same Teflon vessel. The detection limit of the method was 0.14 ng g^–1 solution. Buckwheat seeds from untreated plants contained 47 ng g^–1 of Se and 394 ng g^–1 from plants after foliar fertilisation with Se. Pumpkin seeds from untreated plants contained 108 ng g^–1 of Se, and 381 ng g^–1 of Se from Se-treated plants, all per lyophilised sample. Se content in lyophilised pumpkin fruit was 15 ng g^–1 in untreated plants and 20 ng g^–1 in Se-treated pumpkin plants. It is thus feasible to enhance Se content in buckwheat and pumpkin seeds by foliar fertilisation, making them a rich source of dietary Se and useful as a raw material for enriched food products.     

Effect of steaming,freezing, and re-steaming on the texture properties of non-glutinous rice cakes

The effects of steaming time (6, 8, and 10 min), freezing storage period, and re-steaming for thawing on the textural properties of non-glutinous rice cakes (baekseolgi) were investigated. As the steaming time increased, the rice cakes softened. In particular, the sample that was steamed for 10 min showed lower hardness than those steamed for shorter periods. A short period of steaming was insufficient for water bound to the surface of the starch granules to penetrate the granules in the dough. During the re-steaming process of the frozen non-glutinous rice cake samples, the retrogradation of starch and water syneresis contributed to the increased hardness of non-glutinous rice cakes.     

Preparation and Characterization of Nanocomposites from Whey Protein Concentrate Activated with Lycopene

The production and characterization of nanocomposites based on whey protein concentrate (WPC) and montmorilonite (MMT) incorporated with lycopene as a functional substance is presented and discussed as an alternative biomaterial for potential uses in foodstuff applications. A full factorial design with varying levels of MMT (0% and 2% in w/w) and lycopene (0%, 6%, and 12% in w/w) was used. Color, light transmission, film transparency, moisture, density, solubility, water vapor permeability, and antioxidant activity of the resulting materials were evaluated. Results indicated that lycopene and MMT nanoparticles were successfully included in WPC films using the casting/evaporation method. Inclusion of 2% w/w of MMT in the polymeric matrix significantly improved barrier property against water vapor. Lycopene, besides its good red coloring ability, provided to the films antioxidant activity and UV‐vis light protection. These findings open a new perspective for the use of materials for bioactive packaging applications.     

Flow characteristics of fresh air discharged from a ventilation duct for mine ventilation

Journal of Mechanical Science and Technology - Regarding mine ventilation in a tunnel with one mining face, the turbulent flow structure and Mean age of air (MAA) of fresh air discharged from the...     

The effect of the viscosity ratio of dispersed phase to matrix on the rheological,morphological, and mechanical properties of polymer blends containing a LCP

The effect of the viscosity ratio of the dispersed LCP phase to the polystyrene/poly(phenylene oxide) (PS/PPO) thermoplastic matrix on the rheological, morphological, and resultant mechanical properties of the LCP blends was investigated. The viscosity of PS/PPO is largely dependent on the blend composition, so that different levels of viscosity ratios of dispersed LCP phase to PS/PPO thermoplastic matrix are obtained by using PS/PPO premixtures of different blend ratios as a thermoplastic matrix. When the viscosity of the LCP dispersed phase is lower than that of the thermoplastic matrix, finely distributed fibril structure of LCP is obtained. Tensile modulus of injection molded specimens show a positive deviation from the additive rule when the viscosity ratio (η_LCP/η_matrix) is smaller than unity. These improvements in tensile modulus are attributed to the formation of finely distributed LCP fibrils. © 1996 John Wiley & Sons, Inc.     

Migratory behaviour of adult fast-growing brown trout (Salmo trutta,L.) In relation to water flow in a regulated Norwegian river

The migration pattern of spawners of brown trout (Salmo trutta) in relation to water flow was analysed by radio-tracking in the regulated River Gudbrandsdalslågen, Norway. During the upstream spawning migration in the high flow period, trout (2–12 kg) were caught, tagged and released 15 km downstream of a fish ladder at the Hunderfossen waterfall. The released fish displayed a systematic and directional upstream movement to the outlet of the tunnel from the hydroelectricity plant. In autumn and winter there is a minimum water discharge of 20–2 m³/s on p.s. in the river between the dam and the outlet of the tunnel, which has a discharge of 200–300 m³/s. When the water flowing over the Hunderfossen dam decreased to 20 m³/s, the ascent of brown trout up the river stopped and fish periodically entered the power plant tunnel. To determine the flow necessary to attract fish into the spawning reach above the tunnel outlet, two experiments were undertaken using 12 and 17 radio-tagged trout. In the first experiment, 60 m³/s of water released for 24 h resulted in the migration of 50% of the trout up the river. The second experiment, releasing 60 m³/s for 24 h, followed by 30 m³/s for 24 h two days later, resulted in the migration of 60% of the trout. Only one fish ascended the river at a flow of 30 m³/s. It is recommended that a repeated release of water at 60 m³/s is made in periods of minimum water discharge to save the spawning migration. The results demonstrate the advantage of using radio-tracking in experiments dealing with fish migration in relation to water-flow management.     

Lysophosphatidylserine Induces MUC5AC Production via the Feedforward Regulation of the TACE-EGFR-ERK Pathway in Airway Epithelial Cells in a Receptor-Independent Manner

Lysophosphatidylserine (LysoPS) is an amphipathic lysophospholipid that mediates a broad spectrum of inflammatory responses through a poorly characterized mechanism. Because LysoPS levels can rise in a variety of pathological conditions, we sought to investigate LysoPS’s potential role in airway epithelial cells that actively participate in lung homeostasis. Here, we report a previously unappreciated function of LysoPS in production of a mucin component, MUC5AC, in the airway epithelial cells. LysoPS stimulated lung epithelial cells to produce MUC5AC via signaling pathways involving TACE, EGFR, and ERK. Specifically, LysoPS- dependent biphasic activation of ERK resulted in TGF-α secretion and strong EGFR phosphorylation leading to MUC5AC production. Collectively, LysoPS induces the expression of MUC5AC via a feedback loop composed of proligand synthesis and its proteolysis by TACE and following autocrine EGFR activation. To our surprise, we were not able to find a role of GPCRs and TLR2, known LyoPS receptors in LysoPS-induced MUC5AC production in airway epithelial cells, suggesting a potential receptor-independent action of LysoPS during inflammation. This study provides new insight into the potential function and mechanism of LysoPS as an emerging lipid mediator in airway inflammation.     

Sn self-doped α-Fe2O3 nanobranch arrays supported on a transparent,conductive SnO2 trunk to improve photoelectrochemical water oxidation

We produced hierarchically branched Fe₂O₃ nanorods on a Sb:SnO₂ transparent conducting oxide (TCO) nanobelt structure as photoanodes for photoelectrochemical water splitting. Single-crystalline SnO₂ nanobelts (NBs) surrounded by Fe₂O₃ nanorods (NRs) were synthesized by thermal evaporation, then underwent chemical bath deposition and annealing. When Fe₂O₃ was crystallized by annealing, Sn was diffused from SnO₂ NBs and incorporated to Fe₂O₃ NRs, which was confirmed through Energy dispersive spectroscopy. Unlike previous high temperature sintering (∼800 °C), Sn doped hematite NRs were obtained at a low temperature (∼650 °C). This occurred since SnO₂ NBs directly connected to Fe₂O₃ NRs are an abundant source of Sn dopant. The 3D hematite NRs on SnO₂ NBs annealed at 650 °C produce a photocurrent density of 0.88 mA/cm² at 1.23 V vs. RHE, which is 3 times higher than that of hematite NRs on a fluorine doped tin oxide (FTO) glass substrate annealed at the same temperature. The enhanced photocurrent is attributed to the improved electrical conductivity of Fe₂O₃ NRs by Sn doping, the efficient electron transport pathway by TCO nanowire and the increased surface area by hierarchically branched structure.