631 research outputs found

    Immobilisation of glycosidases from commercial preparation on magnetic beads: Part 2: Aroma enhancement in wine using immobilised glycosidases

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    Most of the terpenes in wines are conjugated to various sugars, representing a significant reservoir of aromatic precursors. To promote the release of these terpenes, certain enzymes, such as β-glucosidase, α-arabinosidase and α-rhamnosidase, are necessary. A simple and cost-effective procedure for the immobilisation of multiple glycosidase activities (β-D-glucopyranosidase, α-L-arabinofuranosidase, α-L-rhamnopyranosidase and β-D-xylopyranosidase) from commercial Aspergillus niger preparation onto magnetic beads as carriers was developed as reported in Part 1 (Ferner et al. 2016).The aim of this work was to analyse a possible application of this immobilised biocatalyst due to its well-known advantages over soluble enzyme preparations – that is, control of the reaction process and preparation of enzyme-free products. Volatile compounds were analysed by gas chromatography (mass spectrometric detection). After the treatment of the model wine with different glycosides and white wine with immobilised glycosidases, the amount of free terpenes was significantly increased with respect to that of the control wine.The results of this study are of considerable interest for possible future applications of immobilised enzymes in the wine-making industry

    Species boundaries in Philippine montane forest skinks (Genus Sphenomorphus): three new species from the mountains of Luzon and clarification of the status of the poorly known S. beyeri, S. knollmanae, and S. laterimaculatus

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    Recent collections of Sphenomorphus beyeri Taylor 1915 from the type locality (Mt. Banahao, Luzon Isl., Philippines) serve as the basis for a thorough analysis of topotypic variation in external morphology within the species, and allow for detailed comparisons to other taxa. We clarify the taxonomic status of S. beyeri with respect to other, phenotypically similar species and evaluate species boundaries between allopatric populations referred to this taxon. The high elevation (1400–1700 m) population of Sphenomorphus (Brown et al., 1995a) from the Zambales Mountains and Bataan Peninsula of Luzon Island (previously referred by us to S. beyeri) is a new species that we describe here. We also describe two additional new species from the isolated, high elevation (1650–1750 m) forests of the Northern Cordillera and the Sierra Madre of Luzon, specimens of both of which had been previously identified as S. beyeri. All three new species differ from each other and all other Sphenomorphus species by scalation, body size, and coloration and all have non-overlapping distributions, associated with separate, isolated, geological components of Luzon Island. In this paper we also formally redescribe S. beyeri on the basis of a large series of specimens from the type locality (Mt. Banahao, southern Luzon Island) that we have accumulated over the last 15 years. We place S. knollmanae Brown, Ruedas, and Ferner 1995 in synonymy with S. laterimaculatus (Brown and Alcala, 1980) and redescribe the latter species on the basis of the holotype and 20 additional newly collected specimens from six localities on the Bicol Peninsula of Luzon Island and Marinduque Island. These and other data suggest that species boundaries in Philippine Sphenomorphus are poorly understood and that taxonomic diversity is substantially underestimated and in need of comprehensive taxonomic review

    Contested resources: unions, employers, and the adoption of new work practices in US and UK telecommunications

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    The pattern of adoption of high-performance work practices has been explained in terms of strategic contingency and in terms of union presence. We compare the post-deregulation/privatization changes in work practice at AT&T, Bell Atlantic and British Telecom. On the basis of these cases, we argue that the choice of new work practices should be understood as a consequence not only of the company's resources or changes in its environment, nor of a simple union presence, but also as a consequence of the practices' effects on union power, the nature of the union's engagement, and the union's strategic choices

    Convergence versus Divergence: Testing Varieties of Capitalism Perspective on the Globalization of Business Practices

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    This paper analyses links between intra-organizational adaptation and institutional variation across countries. Using the varieties of capitalism viewpoint, we examine strategic options open to multinational firms operating simultaneously in liberal market economies and coordinated market economies. A holistic perspective is achieved by implementing an original ‘index of institutional impact.’ Data are drawn from a survey of the subsidiaries of German firms in the UK in 2007. The results suggest that pressure towards accepting local practices for multinational firms varies across the dimensions in which firms resolve coordination problems, inciting speedy convergence in some, but allowing for maintaining distinctive practices in other

    Neurofibromatosis

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    Neurofibromatosis (NF) is one of the most common genetic disorders. Inherited in an autosomal dominant fashion, this phacomatosis is classified into two genetically distinct subtypes characterized by multiple cutaneous lesions and tumors of the peripheral and central nervous system. Neurofibromatosis type 1 (NF1), also referred to as Recklinghausen's disease, affects about 1 in 3500 individuals and presents with a variety of characteristic abnormalities of the skin and the peripheral nervous system. Neurofibromatosis type 2 (NF2), previously termed central neurofibromatosis, is much more rare occurring in less than 1 in 25 000 individuals. Often first clinical signs of NF2 become apparent in the late teens with a sudden loss of hearing due to the development of bi-or unilateral vestibular schwannomas. In addition NF2 patients may suffer from further nervous tissue tumors such as meningiomas or gliomas. This review summarizes the characteristic features of the two forms of NF and outlines commonalities and distinctions between NF1 and NF2

    How do MNC R&D laboratory roles affect employee international assignments?

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    Research and development (R&D) employees are important human resources for multinational corporations (MNCs) as they are the driving force behind the advancement of innovative ideas and products. International assignments of these employees can be a unique way to upgrade their expertise; allowing them to effectively recombine their unique human resources to progress existing knowledge and advance new ones. This study aims to investigate the effect of the roles of R&D laboratories in which these employees work on the international assignments they undertake. We categorise R&D laboratory roles into those of the support laboratory, the locally integrated laboratory and the internationally interdependent laboratory. Based on the theory of resource recombinations, we hypothesise that R&D employees in support laboratories are not likely to assume international assignments, whereas those in locally integrated and internationally interdependent laboratories are likely to assume international assignments. The empirical evidence, which draws from research conducted on 559 professionals in 66 MNC subsidiaries based in Greece, provides support to our hypotheses. The resource recombinations theory that extends the resource based view can effectively illuminate the international assignment field. Also, research may provide more emphasis on the close work context of R&D scientists rather than analyse their demographic characteristics, the latter being the focus of scholarly practice hitherto
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