Alterations in growth and branching of Neurospora crassa caused by sub-inhibitory concentrations of antifungal agents

Six antifungal agents at subinhibitory concentrations were used for investigating their ability to affect the growth and branching in Neurospora crassa. Among the antifungals herein used, the azole agent ketoconazole at 0.5 mu g/ml inhibited radial growth more than fluconazole at 5.0 mu g/ml while amphotericin B at 0.05 mu g/ml was more effective than nystatin at 0.05 mu g/ml. Morphological alterations in hyphae were observed in the presence of griseofulvin, ketoconazole and terbinafine at the established concentrations. The antifungal agents were more effective on vegetative growth than on conidial germination. Terbinafine markedly reduced growth unit length (GU) by 54.89%, and caused mycelia to become hyperbranched. In all cases, there was a high correlation between hyphal length and number of tips (r > 0.9). All our results showed highly significant differences by ANOVA, (p < 0.001, alpha = 0.05). Considering that the hyphal tip is the main interface between the fungus and its environment/through which enzymes and toxins are secreted and nutrients absorbed, it would not be desirable to obtain a hyperbranched mycelia with inefficient doses of antifungal drugs.

In vitro studies of cutaneous retention of magnetic nanoemulsion loaded with zinc phthalocyanine for synergic use in skin cancer treatment

In this study was developed a new nano drug delivery system (NDDS) based on association of biodegradable surfactants with biocompatible magnetic fluid of maguemita citrate derivative. This formulation consists in a magnetic emulsion with nanostructured colloidal particles. Preliminary in vitro experiments showed that the formulation presents a great potential for synergic application in the topical release of photosensitizer drug (PS) and excellent target tissue properties in the photodynamic therapy (PDT) combined with hyperthermia (HPT) protocols. The physical chemistry characterization and in vitro assays were carried out by Zn(II) Phtalocyanine (ZnPc) photosensitizer incorporated into NDDS in the absence and the presence of magnetic fluid, showed good results and high biocompatibility. In vitro experiments were accomplished by tape-stripping protocols for quanti. cation of drug association with different skin tissue layers. This technique is a classical method for analyses of drug release in stratum corneum and epidermis+ dermis skin layers. The NDDS formulations were applied directly in pig skin (tissue model) fixed in the cell`s Franz device with receptor medium container with a PBS/EtOH 20% solution (10mM, pH 7.4) at 37 degrees C. After 12 h of topical administration stratum corneum was removed from fifty tapes and the ZnPc retained was evaluated by solvent extraction in dimetil-sulphoxide under ultrasonic bath. These results indicated that magnetic nanoemulsion (MNE) increase the drug release on the deeper skin layers when compared with classical formulation in the absence of magnetic particles. This could be related with the increase of biocompatibility of NDDS due to the great affinity for the polar extracelullar matrix in the skin and also for the increase in the drug partition inside of corneocites wall. (C) 2008 Elsevier B.V. All rights reserved.

Role of phospholipase C and protein kinase C in Aspergillus nidulans during growth on pectin or glucose: Effects on germination and duplication cycle

The effects of PLC and Pkc inhibitors on Aspergillus nidulans depend on the carbon source. PLC inhibitors Spm and C48/80 delayed the first nuclear division in cultures growing on glucose, but stimulated it in media supplemented with pectin. Less intense were these effects on the mutant transformed with PLC-A gene rupture (AP27). Neomycin also delayed the germination in cultures growing on glucose or pectin; however, on glucose, the nuclear division was inhibited whereas in pectin it was stimulated. These effects were minor in AP27. The effects of Ro-31-8425 and BIM (both Pkc inhibitors) were also opposite for cultures growing on glucose or pectin. On glucose cultures of both strains BIM delayed germination and the first nuclear division, whereas on pectin both parameters were stimulated. Opposite effects were also detected when the cultures were growing on glucose or pectin in the presence of Ro-31-8425.

The 2008 update of the Aspergillus nidulans genome annotation: A community effort

The identification and annotation of protein-coding genes is one of the primary goals of whole-genome sequencing projects, and the accuracy of predicting the primary protein products of gene expression is vital to the interpretation of the available data and the design of downstream functional applications. Nevertheless, the comprehensive annotation of eukaryotic genomes remains a considerable challenge. Many genomes submitted to public databases, including those of major model organisms, contain significant numbers of wrong and incomplete gene predictions. We present a community-based reannotation of the Aspergillus nidulans genome with the primary goal of increasing the number and quality of protein functional assignments through the careful review of experts in the field of fungal biology. (C) 2009 Elsevier Inc. All rights reserved.

Staphylococcus hominis subsp novobiosepticus strains causing nosocomial bloodstream infection in Brazil

To report the isolation of six Staphylococcus hominis subsp. novobiosepticus (SHN) strains from hospitalized patients with bloodstream infections in two Brazilian hospitals and to characterize their susceptibility profile to several antimicrobials. Species identification was performed by biochemical methods and sodA gene sequencing. The MICs of antimicrobials were determined by broth and agar dilution methods and by Etest. Isolates were typed by PFGE and PCR amplification was used to detect the ccr gene complex and the mec class. Morphometric evaluation of cell wall was performed by transmission electron microscopy (TEM). Susceptibility profiles indicated that the majority of isolates (five) were multidrug-resistant. Overlapping and multiplex PCR showed that five out of the six strains harboured SCCmec type III with class A mec and type 3 ccr. The initial vancomycin MIC value of 4 mg/L for these strains increased to 16-32 mg/L after growth for 10 days in BHI broth supplemented with this antimicrobial. TEM indicated that vancomycin resistance was associated with cell wall thickening and to another mechanism not fully elucidated. Only one SHN strain was oxacillin- and vancomycin-susceptible. The nosocomial infections in at least five of the patients from both hospitals were caused by a single clone of SHN. It is very important to consider SHN strains as the cause of nosocomial infections. The clinical implications resulting from the pattern of multidrug resistance in these strains may be complicated by the emergence of vancomycin resistance.

Paracoccin from Paracoccidioides brasiliensis; purification through affinity with chitin and identification of N-acetyl-beta-D-glucosaminidase activity

The dimorphic fungus Paracoccidioides brasiliensis is the causative agent of paracoccidioidomycosis, the most frequent systemic mycosis in Latin America. Our group has been working with paracoccin, a P. brasiliensis lectin with MM 70 kDa. which is purified by affinity, with immobilized N-acetylglucosamine (GlcNAc). Paracoccin has been described to play a role in fungal adhesion to extracellular matrix components and to induce high and persistent levels or TNF alpha. and nitric oxide production by macrophages. In the cell wall, paracoccin colocalizes with the beta-1,4-homopolymer of GlcNAc into the budding sites of the P. brasiliensis yeast cell. In this paper we present a protocol for the chitin-affinity purification or paracoccin. This procedure provided higher yields than those achieved by means of the technique based oil the affinity of this lectin with GlcNAc and had an impact on downstream assays. SDS-PAGE and Western blot analysis revealed similarities between the N-acetylglucosamine- and chitin-bound fractions, confirmed by MALDI-TOF-MS of trypsinic peptides. Western blot of two-dimensional gel electrophoresis of the yeast extract showed a major spot with M(r) 70000 and pl approximately 5.63. Moreover, an N-acetyl-beta-D-glucosaminidase activity was reported for paracoccin, thereby providing new insights into the mechanisms that lead to cell wall remodelling and opening new perspectives for its structural characterization. Copyright (C) 2009 John Wiley & Sons. Ltd.

Sketch design drawing, Hill House, Chapel Hill, Brisbane

Three-dimensional projection sketch showing roof forms and wall finishes.

Warehouse, PNG Coffee Industry Board Office and Warehouse, Goroka

View of exterior wall to warehouse.

Effects of temperature-dependent viscosity variation on entropy generation, heat and fluid flow through a porous-saturated duct of rectangular cross-section

Effect of temperature-dependent viscosity on fully developed forced convection in a duct of rectangular cross-section occupied by a fluid-saturated porous medium is investigated analytically. The Darcy flow model is applied and the viscosity-temperature relation is assumed to be an inverse-linear one. The case of uniform heat flux on the walls, i.e. the H boundary condition in the terminology of Kays and Crawford, is treated. For the case of a fluid whose viscosity decreases with temperature, it is found that the effect of the variation is to increase the Nusselt number for heated walls. Having found the velocity and the temperature distribution, the second law of thermodynamics is invoked to find the local and average entropy generation rate. Expressions for the entropy generation rate, the Bejan number, the heat transfer irreversibility, and the fluid flow irreversibility are presented in terms of the Brinkman number, the Péclet number, the viscosity variation number, the dimensionless wall heat flux, and the aspect ratio (width to height ratio). These expressions let a parametric study of the problem based on which it is observed that the entropy generated due to flow in a duct of square cross-section is more than those of rectangular counterparts while increasing the aspect ratio decreases the entropy generation rate similar to what previously reported for the clear flow case.

Heat transfer and entropy generation optimization of forced convection in a porous-saturated duct of rectangular cross-section

We investigate analytically the first and the second law characteristics of fully developed forced convection inside a porous-saturated duct of rectangular cross-section. The Darcy-Brinkman flow model is employed. Three different types of thermal boundary conditions are examined. Expressions for the Nusselt number, the Bejan number, and the dimensionless entropy generation rate are presented in terms of the system parameters. The conclusions of this analytical study will make it possible to compare, evaluate, and optimize alternative rectangular duct design options in terms of heat transfer, pressure drop, and entropy generation. (c) 2006 Elsevier Ltd. All rights reserved.

Sillon de Talbert, Pleubian, Bretagne, France

Coastal photograph of Sillon du Talbert, L'Armor, Pleubian on 16 April 2004 low tide. End of the Sillon, looking N-N-E at the Archipel d'Ollone. The Sillon du Talbert is a natural thin 3-km long tongue made of "galets" (pebbles about 5 to 20 cm) and sand. It is located at the tip of a peninsula between the estuaries of the rivers Jaudy (Le Jaudy) and Trieux (Le Trieux) next to Ile de Bre´hat. At the end of the Sillon, there is an archipel of small islands and rocks called "Archipel d'Ollone" (Ollone archipel), also called the Talbert islands (Iles de Talbert) by the locals. The Sillon du Talbert (or Sillon de Talbert) is an important reserve of flora and fauna. The Sillon was damaged by locals using stones for construction until 1928, and by the Germans, who used stones for the Ile Blanche bunker system construction in 1943 as part of the WWII Atlantic wall. (Coastal Photograph by Hubert Chanson, Department of Civil Engineering, the University of Queensland, Brisbane, Queensland 4072, Australia.)

Turbulence in Hydraulic Jumps: Experimental Measurements

A hydraulic jump is the transition from a supercritical open channel flow to a subcritical regime. It is characterised by a highly turbulent flow with macro-scale vortices, some kinetic energy dissipation and a bubbly two-phase flow structure. New air-water flow measurements were performed in hydraulic jump flows for a range of inflow Froude numbers. The experiments were conducted in a large-size facility using two types of phase-detection intrusive probes: i.e., single-tip and double-tip conductivity probes. These were complemented by some measurements of free-surface fluctuations using ultrasonic displacement meters. The present study was focused on the turbulence characteristics of hydraulic jumps with partially-developed inflow conditions. The void fraction measurements showed the presence of an advective diffusion shear layer in which the void fractions profiles matched closely an analytical solution of the advective diffusion equation for air bubbles. The present results highlighted some influence of the inflow Froude number onto the air bubble entrainment process. At the largest Froude numbers, the advected air bubbles were more thoroughly dispersed vertically, and larger amount of air bubbles were detected in the turbulent shear layer. In the air-water mixing layer, the maximum void fraction and bubble count rate data showed some longitudinal decay function in the flow direction. Such trends were previously reported in the literature. The measurements of interfacial velocity and turbulence level distributions provided new information on the turbulent velocity field in the highly-aerated shear region. The present data suggested some longitudinal decay of the turbulence intensity. The velocity profiles tended to follow a wall jet flow pattern. The air–water turbulent time and length scales were deduced from some auto- and cross-correlation analyses based upon the method of CHANSON (2006,2007). The results provided the integral turbulent time and length scales of the eddy structures advecting the air bubbles in the developing shear layer. The experimental data showed that the auto-correlation time scale Txx was larger than the transverse cross-correlation time scale Txz. The integral turbulence length scale Lxz was a function of the inflow conditions, of the streamwise position (x-x1)/d1 and vertical elevation y/d1. Herein the dimensionless integral turbulent length scale Lxz/d1 was closely related to the inflow depth: i.e., Lxz/d1 = 0.2 to 0.8, with Lxz increasing towards the free-surface. The free-surface fluctuations measurements showed large turbulent fluctuations that reflected the dynamic, unsteady structure of the hydraulic jumps. A linear relationship was found between the normalized maximum free-surface fluctuation and the inflow Froude number.

Effects of viscous dissipation and boundary conditions on forced convection in a channel occupied by a saturated porous medium

Forced convection with viscous dissipation in a parallel plate channel filled by a saturated porous medium is investigated numerically. Three different viscous dissipation models are examined. Two different sets of wall conditions are considered: isothermal and isoflux. Analytical expressions are also presented for the asymptotic temperature profile and the asymptotic Nusselt number. With isothermal walls, the Brinkman number significantly influences the developing Nusselt number but not the asymptotic one. At constant wall heat flux, both the developing and the asymptotic Nusselt numbers are affected by the value of the Brinkman number. The Nusselt number is sensitive to the porous medium shape factor under all conditions considered.

Effects of viscous dissipation and boundary conditions on forced convection in a channel occupied by a saturated porous medium

Forced convection with viscous dissipation in a parallel plate channel filled by a saturated porous medium is investigated numerically. Three different viscous dissipation models are examined. Two different sets of wall conditions are considered: isothermal and isoflux. Analytical expressions are also presented for the asymptotic temperature profile and the asymptotic Nusselt number. With isothermal walls, the Brinkman number significantly influences the developing Nusselt number but not the asymptotic one. At constant wall heat flux, both the developing and the asymptotic Nusselt numbers are affected by the value of the Brinkman number. The Nusselt number is sensitive to the porous medium shape factor under all conditions considered.

Sections of some Carboniferous dispersed spores

Sections of microspores, some cingulate, one zonate and one saccate, are discussed and illustrated. It is shown that sections aid the elucidation of wall structures; thus diagnoses can be more precisely written and this may eventually remove some classificatory difficulties. A sectioning technique is described.