The effect of temperature on growth and cellulase (β-1,4-endoglucanase) production in the compost fungusChaetomium thermophile var.dissitum

Chaetomium thermophile var.dissitum, isolated from an experimental urban refuse compost, had the following growth characteristics: Minimum temperature, 27±1°C; optimum, 45–50°C; maximum, 57±1°C; pH optimum 5.5–6.0.A number of carbohydrates could be used for growth, but cellulase formation measured with carboxymethylcellulose as substrate was initiated only on cellulose or xylan. With cellulose as the carbon source, cellulase accumulation in the culture filtrate followed closely that of growth, when the temperature was varied. pH optimum for the cellulase system was 5.0.The optimum temperature for cellulase activity with carboxymethylcellulose as substrate varied between 77°C with 1/2 h incubation time and 58°C with 10 h incubation time.With cotton as substrate, the optimum temperature was 58°C regardless of incubation time. Carboxymethylcellulose had a higher stabilizing effect on the enzyme than cotton. The temperature stability of the cellulase was highest at pH 6.0.     

Influence of lifting technique on perceptual and cardiovascular responses to submaximal repetitive lifting

Oxygen consumption ( O₂), heart rate, ventilation and central rating of perceived exertion (RPE) in repetitive lifting while executing squat and stoop techniques were investigated in ten male forestry workers. In all five mass/frequency combinations studied, O₂ was significantly higher for the squat than for the stoop technique. No differences were found in RPE between the techniques. The O₂ and RPE recordings were also related to those obtained during maximal repetitive lifting (same lifting technique) and maximal treadmill running. The O₂ expressed as a percentage of that obtained during maximal repetitive lifting with the same lifting technique was defined as relative aerobic intensity (% O_{2max, lifting}). The % O_{2max, lifting} was not significantly different between the techniques except for the lowest mass lifted (1 kg). This study therefore would support the hypothesis that RPE is more closely related to % O_{2max, lifting} than to absolute aerobic intensity. Related to maximal treadmill running, it was demonstrated for both lifting techniques that relative RPE (percentage of the RPE during maximal running) was more accurate than relative O₂ (percentage of maximal O₂ during maximal running) for determining the % O_{2max, lifting} in repetitive lifting. The study showed that the higher O₂ during squat. lifting compared to stoop lifting was caused by the O₂ expended in lifting and lowering the body rather than the O₂ expended lifting and lowering the external mass. It was concluded that the stoop technique was not superior to the squat technique in terms of central RPE. Based on % O_{2max, lifting}, there may be a rationale for choosing the stoop technique during repetitive lifting with light masses, but not with heavy masses.     

Creating a sustainable commercial harvest of <Emphasis Type="Italic">Laminaria hyperborea</Emphasis>, in Norway

The mechanized harvesting of Laminaria hyperborea in Norway began nearly 50 years ago. Based on a clear understanding of the ecology and life cycle of L. hyperborea as well as the ecosystem, a sustainable management program for the harvest was created with a 5-year cycle and rotating zones in fields as the foundation of the plan. This has allowed a steady annual harvest of 130,000–180,000 t wet weight, depending on market demand. In the last decade, the Norwegian government, working with industry and other stakeholders, has produced more refined policies/documents governing the harvest. This macroalgal harvest plan provides an excellent example for resource managers in other parts of the world laboring to create sustainable harvest management plans.     

Comparative Genomics to Delineate Pathogenic Potential in Non-O157 Shiga Toxin-Producing Escherichia coli (STEC) from Patients with and without Haemolytic Uremic Syndrome (HUS) in Norway

Shiga toxin-producing Escherichia coli (STEC) cause infections in humans ranging from asymptomatic carriage to bloody diarrhoea and haemolytic uremic syndrome (HUS). Here we present whole genome comparison of Norwegian non-O157 STEC strains with the aim to distinguish between strains with the potential to cause HUS and less virulent strains. Whole genome sequencing and comparisons were performed across 95 non-O157 STEC strains. Twenty-three of these were classified as HUS-associated, including strains from patients with HUS (n = 19) and persons with an epidemiological link to a HUS-case (n = 4). Genomic comparison revealed considerable heterogeneity in gene content across the 95 STEC strains. A clear difference in gene profile was observed between strains with and without the Locus of Enterocyte Effacement (LEE) pathogenicity island. Phylogenetic analysis of the core genome showed high degree of diversity among the STEC strains, but all HUS-associated STEC strains were distributed in two distinct clusters within phylogroup B1. However, non-HUS strains were also found in these clusters. A number of accessory genes were found to be significantly overrepresented among HUS-associated STEC, but none of them were unique to this group of strains, suggesting that different sets of genes may contribute to the pathogenic potential in different phylogenetic STEC lineages. In this study we were not able to clearly distinguish between HUS-associated and non-HUS non-O157 STEC by extensive genome comparisons. Our results indicate that STECs from different phylogenetic backgrounds have independently acquired virulence genes that determine pathogenic potential, and that the content of such genes is overlapping between HUS-associated and non-HUS strains.     

First fungus gnats of genus Manota Williston (Diptera: Mycetophilidae) from Japan

The genus Manota is recorded from Japan for the first time. Three new species, Manota satoyamanis, Manota indahae and Manota tunoae spp. nov., are described, based on specimens collected in an ecological sampling program of arthropods in the “satoyama” landscape of Ishikawa Prefecture. “Satoyama” represents the traditional rural landscape of Japan, which is characterized by a mosaic of secondary forests, plantations, ponds and rice paddy fields. The new species raise the number of Palearctic Manota species from five to eight.     

The development of new algorithms for remote sensing of snow conditions based on data from the catchment of Øvre Heimdalsvatn and the vicinity

The catchment of Øvre Heimdalsvatn and the surrounding area was established as a site for snow remote sensing algorithm development, calibration and validation in 1997. Information on snow cover and snowmelt are important for understanding the timing and scale of many lake ecosystem processes. Field campaigns combined with data from airborne sensors and spaceborne high-resolution sensors have been used as reference data in experiments over many years. Several satellite sensors have been utilised in the development of new algorithms, including Terra MODIS and Envisat ASAR. The experiments have been motivated by operational prospects for snow hydrology, meteorology and climate monitoring by satellite-based remote sensing techniques. This has resulted in new time-series multi-sensor approaches for monitoring of snow cover area (SCA) and snow surface wetness (SSW). The idea was to analyse, on a daily basis, a time series of optical and radar satellite data in multi-sensor models. The SCA algorithm analyses each optical and synthetic aperture radar (SAR) image individually and combines them into a day product based on a set of confidence functions. The SSW algorithm combines information about the development of the snow surface temperature and the snow grain size (SGS) in a time-series analysis. The snow cover algorithm is being evaluated for application in a global climate monitoring system for snow variables. The successful development of these algorithms has led to operational applications of snow monitoring in Norway and Sweden, as well as enabling the prediction of the spring snowmelt flood and thus the initiation of many lake production processes.     

4-Substituted-5(3)-carbamoyl-3(5)-(2-deoxy-β-D-ribofuranosyl)pyrazoles. Application of Palladium Catalyzed Glycal Coupling Methodology to the Synthesis of Pyrazofurin Analogs

Abstract

Analogs of the C-nucleoside pyrazofurin were prepared in 7–9 steps using a key Pd(0)- catalyzed coupling reaction between protected iodopyrazoles 6a and 6b and glycal 8 to form the glycosyl bond. Conditions for this reaction were improved from those previously described for related reactions in order to maximize product yields and eliminate the need for triphenylarsine.

     

Stereocontrolled Transesterification for the Synthesis of Chiral Phosphite Triester Backbone

Abstract

We have developed stereocontrolled transesterification for the synthesis of chiral phosphite mester backbone under basic conditions. Substrate phosphite triesters with phenoxy derivative substituents as leaving groups were separated into individual stereoisomers and reacted with hydroxyl-containing compounds to form desired backbone.

     

Nanoparticle Mediated P-Glycoprotein Silencing for Improved Drug Delivery across the Blood-Brain Barrier: A siRNA-Chitosan Approach

The blood-brain barrier (BBB), composed of tightly organized endothelial cells, limits the availability of drugs to therapeutic targets in the central nervous system. The barrier is maintained by membrane bound efflux pumps efficiently transporting specific xenobiotics back into the blood. The efflux pump P-glycoprotein (P-gp), expressed at high levels in brain endothelial cells, has several drug substrates. Consequently, siRNA mediated silencing of the P-gp gene is one possible strategy how to improve the delivery of drugs to the brain. Herein, we investigated the potential of siRNA-chitosan nanoparticles in silencing P-gp in a BBB model. We show that the transfection of rat brain endothelial cells mediated effective knockdown of P-gp with subsequent decrease in P-gp substrate efflux. This resulted in increased cellular delivery and efficacy of the model drug doxorubicin.