Application of transglutaminases in the modification of wool textiles

The use of the protein-crosslinking enzymes transglutaminases (EC 2.3.2.13), as biocatalysts in the processing of wool textiles offers a variety of exciting and realistic possibilities, which include reducing the propensity of wool fabric to shrink and maintaining or increasing fabric strength. Guinea pig liver (GPL) transglutaminase or the microbial transglutaminase isolated from Streptoverticilium mobaraense, when applied to wool either alone or following a protease treatment, resulted in an increase in wool yarn and fabric strength (up to a 25% increase compared to a control). This indicates that transglutaminases can remediate the negative effects of proteolytic treatments in terms of loss in fibre strength. Incubation of samples pretreated with different oxidative and reducing agents with both sources of transglutaminases led to significant increases in tensile strength for all samples tested, suggesting that yarn strength lost following chemical treatments can also be recovered. The two different transglutaminases (TGases) could also impart a significant reduction in fabric shrinkage. The incorporation of primary amine transglutaminase substrates into wool fibres, with a view to altering wool functionality, was demonstrated using the incorporation of the fluorescent primary amine fluorescein cadaverine (FC). Incubation of wool with this fluorescent amine and transglutaminase led to high levels of incorporation into the fibres. The treatment of wool textiles with transglutaminases indicates that a number of novel and radically different finishes for wool textiles can be developed.

Fibre Bragg gratings in polymer optical fibre for applications in sensing

This thesis presents the potential sensing applications of fibre Bragg gratings in polymer optical fibres. Fibre Bragg gratings are fabricated in different kinds of polymer optical fibres, including Poly methyl methacrylate (PMMA) and TOPAS cyclic olefin copolymer based microstructured polymer optical fibres and PMMA based step-index photosensitive polymer optical fibre, using the 325nm continuous wave ultraviolet laser and phase mask technique. The thermal response of fabricated microstructured polymer optical fibre Bragg gratings has been characterized. The PMMA based single mode microstructured polymer optical fibre Bragg gratings exhibit negative non-linear Bragg wavelength shift with temperature, including a quasi-linear region. The thermal sensitivity of such Bragg gratings in the linear region is up to -97pm/°C. A permanent shift in the grating wavelength at room temperature is observed when such gratings are heated above a threshold temperature which can be extended by annealing the fibre before grating inscription. The largest positive Bragg wavelength shift with temperature in transmission is observed in TOPAS based few moded microstructured polymer optical fibre Bragg gratings and the measured temperature sensitivity is 250±0.5pm/°C. Gluing method is developed to maintain stable optical coupling between PMMA based single mode step index polymer optical fibre Bragg gratings and single mode step index silica optical fibre. Being benefit from this success, polymer optical fibre Bragg gratings are able to be characterised for their temperature, humidity and strain sensitivity, which are -48.2±1pm/°C, 38.3±0.5pm per %RH and 1.33±0.04 pm/µ??respectively. These sensitivities have been utilised to achieve several applications. The strain sensitivity of step index polymer optical fibre Bragg grating devices has been exploited in the potential application of the strain condition monitoring of heavy textiles and when being attached to textile specimens with certain type of adhesives. These polymer fibre Bragg grating devices show better strain transfer and lower structure reinforcement than silica optical fibre Bragg grating devices. The humidity sensitivity of step index polymer optical fibre Bragg grating devices is applied to detecting water in jet fuel and is proved to be able to measure water content of less than 20 ppm in Jet fuel. A simultaneous temperature and humidity sensor is also made by attaching a polymer fibre Bragg grating to a silica optical fibre Bragg grating and it shows better humidity measurement accuracy than that of electronic competitors.

Isolation, characterisation and application of novel microbial protein cross-linking enzymes

Microbial transglutaminase is favoured for use in industry over the mammalian isoform, and hence has been utilized, to great effect, as an applied biocatalyst in many industrial areas including the food and textiles industries. There are currently only a limited number of microbial TGase sources known. A number of organisms have been screened for transglutaminase activity using biochemical assays directed towards TGase catalyzed reactions (amine incorporation and peptide cross-linking assay). Of those organisms screened, TGase was identified in a number of isolates including members of the Bacillus and Streptomyces families. In addition, a protein capable of performing a TGase-like reaction was identified in the organism Pseudomonas putida that was deemed immunologically distinct from previously described TGase isoforms, though further work would be required to purify the protein responsible. The genuses Streptoverticillium and Streptomyces are known to be closely related. A number of micro-organisms relating to Streptomyces mobaraensis (formerly Streptoverticillium mobaraensis) have been identified as harboring a TGase enzyme. The exact biological role of Streptomyces TGase is not well understood, though from work undertaken here it would appear to be involved in cell wall growth. Comparison of the purified Streptomyces TGase proteins showed them to exhibit marginally different characteristics in relation to enzymatic activity and pH dependency upon comparison with Streptomyces mobaraensis TGase. In addition, TGase was identified in the organism Saccharomonospora viridis that was found to be genetically identical to that from S. mobaraensis raising questions about the enzymes dissemination in nature. TGase from S. baldaccii was found to be most diverse with respect to enzymatic characteristics whilst still retaining comparable E(y-glutamyl) lysine bond formation to S. mobaraensis TGase. As such S. baldaccii TGase was cloned into an expression vector enabling mass production of the enzyme thereby providing a viable alternative to S. mobaraensis TGase for many industrial processes.

Modeling foreign exchange rate pass-through using the exponential GARCH

In this chapter, the authors use an EGARCH-ECM to estimate the pass-through effects of Foreign Exchange (FX) rate changes and changes in producers' prices for 20 U.K. export sectors. The long-run adjustments of export prices to FX rate changes and changes in producers' prices are within the range of -1.02% (for the Textiles sector) and -17.22% (for the Meat sector). The contemporaneous Pricing-To-Market (PTM) coefficients are within the range of -72.84% (for the Fuels sector) and -8.05% (for the Textiles sector). Short-run FX rate pass-through is not complete even after several months. Rolling EGARCH-ECMs show that the short and long-run effects of changes in FX rate and producers' prices vary substantially, as do asymmetry and volatility estimates before equilibrium is achieved.

Does institutional quality affect firm performance? Insights from a semiparametric approach

Using a novel modeling approach, and cross-country firm level data for the textiles industry, we examine the impact of institutional quality on firm performance. Our methodology allows us to estimate the marginal impact of institutional quality on productivity of each firm. Our results bring into question conventional wisdom about the desirable characteristics of market institutions, which is based on empirical evidence about the impact of institutional quality on the average firm. We demonstrate, for example, that once both the direct impact of a change in institutional quality on total factor productivity and the indirect impact through changes in efficiency of use of factor inputs are taken into account, an increase in labor market rigidity may have a positive impact on firm output, at least for some firms. We also demonstrate that there are significant intra-country variations in the marginal impact of institutional quality, such that the characteristics of “winners” and “losers” will have to be taken into account before policy is introduced to change institutional quality in any direction.

Does human capital endowment of FDI recipient countries really matter? Evidence from cross-country firm level data

The stylized literature on foreign direct investment suggests that developing countries should invest in the human capital of their labour force in order to attract foreign direct investment. However, if educational quality in developing country is uncertain such that formal education is a noisy signal of human capital, it might be rational for multinational enterprises to focus more on job-specific training than on formal education of the labour force. Using cross-country data from the textiles and garments industry, we demonstrate that training indeed has greater impact on firm efficiency in developing countries than formal education of the work force.

Policy, economic federalism, and product market entry:the Indian experience

Productivity growth has long been associated with, among other things, contestability of markets which, in turn, is dependent on the ease with which potential competitors to the incumbent firms can enter the product market. There is a growing consensus that in emerging markets regulatory and institutional factors may have a greater influence on a firm's ability to enter a product market than strategic positions adopted by the incumbent firms. We examine this proposition in the context of India where the industrial policies of the 1980s and the 1990s are widely believed to be pro-incumbent and pro-competition, respectively, thereby providing the setting for a natural experiment with 1991 as the watershed year. In our analysis, we also take into consideration the possibility that the greater economic federalism associated with the reforms of the 1990s may have affected the distribution of industrial units across states after 1991. Our paper, which uses the experiences of the textiles and electrical machinery sectors during the two decades as the basis for the analysis, finds broad support for both these hypotheses.

Entry, reforms complementarity and performance:a tale of two Indian manufacturing sectors

In this paper, we use plant-level data from two Indian industries, namely, electrical machinery and textiles, to examine the empirical relationship between structural reforms like abandonment of entry restrictions to the product market, competition and firm-level productivity and efficiency. These industries have faced different sets of policies since Independence but both were restricted in the adoption of technology and in the development of optimal scales of production. They also belonged to the first set of industries that benefited from the liberalization process started in the 1980s. Our results suggest that both the industries have improved their efficiency and scales of operation by the turn of the century. However, the process of adjustment seems to have been worked out more fully for electrical machinery. We also find evidence of spatial fragmentation of the market as late as 2000–2001. Gains in labour productivity were much more evident in states that either have a strong history of industrial activity or those that have experienced significant improvements in business environment since 1991.

Pricing-to-market using EGARCH-error correction model

In this paper, the authors use an exponential generalized autoregressive conditional heteroscedastic (EGARCH) error-correction model (ECM), that is, EGARCH-ECM, to estimate the pass-through effects of foreign exchange (FX) rates and producers’ prices for 20 U.K. export sectors. The long-run adjustment of export prices to FX rates and producers’ prices is within the range of -1.02% (for the Textiles sector) and -17.22% (for the Meat sector). The contemporaneous pricing-to-market (PTM) coefficient is within the range of -72.84% (for the Fuels sector) and -8.05% (for the Textiles sector). Short-run FX rate pass-through is not complete even after several months. Rolling EGARCH-ECMs show that the short and long-run effects of FX rate and producers’ prices fluctuate substantially as are asymmetry and volatility estimates before equilibrium is achieved.

Does human capital endowment of foreign direct investment recipient countries really matter? evidence from cross-country firm level data

The stylized literature on foreign direct investment (FDI) suggests that developing countries should invest in the human capital of their labor force in order to attract FDI. However, if educational quality in developing country is uncertain such that formal education is a noisy signal of human capital, it might be rational for multinational enterprises to focus more on job-specific training than on formal education of the labor force. Using cross-country data from the textiles and garments industry, we demonstrate that training indeed has a greater impact on firm efficiency in developing countries than formal education of the workforce. © 2013 John Wiley & Sons Ltd.