997 resultados para Key products
Resumo:
A rapid method for the analysis of biomass feedstocks was established to identify the quality of the pyrolysis products likely to impact on bio-oil production. A total of 15 Lolium and Festuca grasses known to exhibit a range of Klason lignin contents were analysed by pyroprobe-GC/MS (Py-GC/MS) to determine the composition of the thermal degradation products of lignin. The identification of key marker compounds which are the derivatives of the three major lignin subunits (G, H, and S) allowed pyroprobe-GC/MS to be statistically correlated to the Klason lignin content of the biomass using the partial least-square method to produce a calibration model. Data from this multivariate modelling procedure was then applied to identify likely "key marker" ions representative of the lignin subunits from the mass spectral data. The combined total abundance of the identified key markers for the lignin subunits exhibited a linear relationship with the Klason lignin content. In addition the effect of alkali metal concentration on optimum pyrolysis characteristics was also examined. Washing of the grass samples removed approximately 70% of the metals and changed the characteristics of the thermal degradation process and products. Overall the data indicate that both the organic and inorganic specification of the biofuel impacts on the pyrolysis process and that pyroprobe-GC/MS is a suitable analytical technique to asses lignin composition. © 2007 Elsevier B.V. All rights reserved.
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New Approach’ Directives now govern the health and safety of most products whether destined for workplace or domestic use. These Directives have been enacted into UK law by various specific legislation principally relating to work equipment, machinery and consumer products. This research investigates whether the risk assessment approach used to ensure the safety of machinery may be applied to consumer products. Crucially, consumer products are subject to the Consumer Protection Act (CPA) 1987, where there is no direct reference to “assessing risk”. This contrasts with the law governing the safety of products used in the workplace, where risk assessment underpins the approach. New Approach Directives are supported by European harmonised standards, and in the case of machinery, further supported by the risk assessment standard, EN 1050. The system regulating consumer product safety is discussed, its key elements identified and a graphical model produced. This model incorporates such matters as conformity assessment, the system of regulation, near miss and accident reporting. A key finding of the research is that New Approach Directives have a common feature of specifying essential performance requirements that provide a hazard prompt-list that can form the basis for a risk assessment (the hazard identification stage). Drawing upon 272 prosecution cases, and with thirty examples examined in detail, this research provides evidence that despite the high degree of regulation, unsafe consumer products still find their way onto the market. The research presents a number of risk assessment tools to help Trading Standards Officers (TSOs) prioritise their work at the initial inspection stage when dealing with subsequent enforcement action.
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The field of free radical biology and medicine continues to move at a tremendous pace, with a constant flow of ground-breaking discoveries. The following collection of papers in this issue of Biochemical Society Transactions highlights several key areas of topical interest, including the crucial role of validated measurements of radicals and reactive oxygen species in underpinning nearly all research in the field, the important advances being made as a result of the overlap of free radical research with the reinvigorated field of lipidomics (driven in part by innovations in MS-based analysis), the acceleration of new insights into the role of oxidative protein modifications (particularly to cysteine residues) in modulating cell signalling, and the effects of free radicals on the functions of mitochondria, extracellular matrix and the immune system. In the present article, we provide a brief overview of these research areas, but, throughout this discussion, it must be remembered that it is the availability of reliable analytical methodologies that will be a key factor in facilitating continuing developments in this exciting research area.
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The advantages of liposomes as delivery systems for peptide, protein and DNA vaccines is well-recognised, unfortunately their application has been stinted by their instability during storage and their limited shelf-life. Further, sterilisation of these systems has been problematic, with degradation of the liposomes being reported after sterilisation using the various techniques available. Work form our laboratory has investigated techniques that can be applied to particulate liposomal vaccines such that they can be prepared in a freeze-dried and sterile format. In this article, we describe techniques for the lyophilisation, cryoprotection and sterilisation of liposomal vaccines. Applying these methods allows for the retention of both the chemical integrity of the lipids and the key physico-chemical characteristics of the liposomes (e.g., particle size, zeta potential, and dynamic viscosity), thus supporting the enhanced transition of liposomal vaccines from the bench to the clinic. © 2006 Elsevier Inc. All rights reserved.
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The aim of this study is to characterise and compare fast pyrolysis product yields from straw, high yielding perennial grasses and hardwoods. Feedstocks selected for this study include: wheat straw (Triticum aestivum), switch grass (Panicum virgatum), miscanthus (Miscanthus x giganteus), willow short rotation coppice (Salix viminalis) and beech wood (Fagus sylvatica). The experimental work is divided into two sections: analytical (TGA and Py-GC-MS) and laboratory scale processing using a continuously fed bubbling fluidized bed reactor with a capacity of up to 1 kg/h. Pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS) has been used to quantify pyrolysis products and simulate fast pyrolysis heating rates, in order to study potential key light and medium volatile decomposition products found in these feedstocks. Py-GC-MS quantification results show that the highest yields of furfural (0.57 wt.%), 2-furanmethanol (0.18 wt.%), levoglucosan (0.73 wt.%), 1,2-benzenediol (0.27 wt.%) and 2-methoxy-4-vinylphenol (0.38 wt.%) were found in switch grass, and that willow SRC produced the highest yield of phenol (0.33 wt.%). The bio-oil higher heating value was highest for switch grass (22.3 MJ/kg). Water content within the bio-oil is highest in the straw and perennial grasses and lowest in the hardwood willow SRC. The high bio-oil and char heating value and low water content found in willow SRC, makes this crop an attractive energy feedstock for fast pyrolysis processing, if the associated production costs and harvest yields can be maintained at current reported values. The bio-oil from switch grass has the highest potential for the production of high value chemicals. © 2013 Elsevier Ltd. All rights reserved.
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While many offline retailers have developed informational websites that offer information on products and prices, the key question for such informational websites is whether they can increase revenues via web-to-store shopping. The current paper draws on the information search literature to specify and test hypotheses regarding the offline revenue impact of adding an informational website. Explicitly considering marketing efforts, a latent class model distinguishes consumer segments with different short-term revenue effects, while a Vector Autoregressive model on these segments reveals different long-term marketing response. We find that the offline revenue impact of the informational website critically depends on the product category and customer segment. The lower online search costs are especially beneficial for sensory products and for customers distant from the store. Moreover, offline revenues increase most for customers with high web visit frequency. We find that customers in some segments buy more and more expensive products, suggesting that online search and offline purchases are complements. In contrast, customers in a particular segment reduce their shopping trips, suggesting their online activities partially substitute for experiential shopping in the physical store. Hence, offline retailers should use specific online activities to target specific product categories and customer segments.
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Although the importance of translation for the development of tissue engineering, regenerative medicine and cell-based therapies is widely recognized, the process of translation is less well understood. This is particularly the case among some early career researchers who may not appreciate the intricacies of translational research or make decisions early in development which later hinders effective translation. Based on our own research and experiences as early career researchers involved in tissue engineering and regenerative medicine translation, we discuss common pitfalls associated with translational research, providing practical solutions and important considerations which will aid process and product development. Suggestions range from effective project management, consideration of key manufacturing, clinical and regulatory matters and means of exploiting research for successful commercialization.
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Introduction - The Dutch implementation of the black border provision in the 2001 European Union Tobacco Products Directive (TPD) is studied to examine the implications of tobacco industry involvement in the implementation phase of the policy process. Methods - A qualitative analysis was conducted of Dutch government documents obtained through Freedom of Information Act requests, triangulated with in-depth interviews with key informants and secondary data sources (publicly available government documents, scientific literature, and news articles). Results - Tobacco manufacturers’ associations were given the opportunity to set implementation specifications via a fast-track deal with the government. The offer of early implementation of the labelling section of the TPD was used as political leverage by the industry, and underpinned by threats of litigation and arguments highlighting the risks of additional public costs and the benefits to the government of expediency and speed. Ultimately, the government agreed to the industry's interpretation, against the advice of the European Commission. Conclusions - The findings highlight the policy risks associated with corporate actors’ ability to use interactions over technical product specifications to influence the implementation of health policy and illustrate the difficulties in limiting industry interference in accordance with Article 5.3 of the Framework Convention on Tobacco Control (FCTC). The implementation phase is particularly vulnerable to industry influence, where negotiation with industry actors may be unavoidable and the practical implications of relatively technical considerations are not always apparent to policymakers. During the implementation of the new TPD 2014/40/EU, government officials are advised to take a proactive role in stipulating technical specifications.
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OBJECTIVES: To examine the volume, relevance and quality of transnational tobacco corporations' (TTCs) evidence that standardised packaging of tobacco products 'won't work', following the UK government's decision to 'wait and see' until further evidence is available. DESIGN: Content analysis. SETTING: We analysed the evidence cited in submissions by the UK's four largest TTCs to the UK Department of Health consultation on standardised packaging in 2012. OUTCOME MEASURES: The volume, relevance (subject matter) and quality (as measured by independence from industry and peer-review) of evidence cited by TTCs was compared with evidence from a systematic review of standardised packaging . Fisher's exact test was used to assess differences in the quality of TTC and systematic review evidence. 100% of the data were second-coded to validate the findings: 94.7% intercoder reliability; all differences were resolved. RESULTS: 77/143 pieces of TTC-cited evidence were used to promote their claim that standardised packaging 'won't work'. Of these, just 17/77 addressed standardised packaging: 14 were industry connected and none were published in peer-reviewed journals. Comparison of TTC and systematic review evidence on standardised packaging showed that the industry evidence was of significantly lower quality in terms of tobacco industry connections and peer-review (p<0.0001). The most relevant TTC evidence (on standardised packaging or packaging generally, n=26) was of significantly lower quality (p<0.0001) than the least relevant (on other topics, n=51). Across the dataset, TTC-connected evidence was significantly less likely to be published in a peer-reviewed journal (p=0.0045). CONCLUSIONS: With few exceptions, evidence cited by TTCs to promote their claim that standardised packaging 'won't work' lacks either policy relevance or key indicators of quality. Policymakers could use these three criteria-subject matter, independence and peer-review status-to critically assess evidence submitted to them by corporate interests via Better Regulation processes.
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Rapidly rising world populations have sparked growing concerns over global food production to meet this increasing demand. Figures released by The World Bank suggest that a 50 % increase in worldwide cereal production is required by 2030. Primary amines are important intermediates in the synthesis of a wide variety of fine chemicals utilised within the agrochemical industry, and hence new 'greener' routes to their low cost manufacture from sustainable resources would permit significantly enhanced crop yields. Early synthetic pathways to primary amines employed stoichiometric (and often toxic) reagents via multi-step protocols, resulting in a large number of by-products and correspondingly high Environmental factors of 50-100 (compared with 1-5 for typical bulk chemicals syntheses). Alternative catalytic routes to primary amines have proven fruitful, however new issues relating to selectivity and deactivation have slowed commercialisation. The potential of heterogeneous catalysts for nitrile hydrogenation to amines has been demonstrated in a simplified reaction framework under benign conditions, but further work is required to improve the atom economy and energy efficiency through developing fundamental insight into nature of the active species and origin of on-stream deactivation. Supported palladium nanoparticles have been investigated for the hydrogenation of crotononitrile to butylamine (Figure 1) under favourable conditions, and the impact of reaction temperature, hydrogen pressure, support and loading upon activity and selectivity to C=C versus CºN activation assessed.
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A szerzők tanulmányukban az információbiztonság egy merőben új, minőségi változást hozó találmányával, a kvantumkulcscserével (QKD-vel – quantum key distribution) foglalkoznak. Céljuk az, hogy az újdonságra mint informatikai biztonsági termékre tekintsenek, és megvizsgálják a bevezetéséről szóló vállalati döntés során felmerülő érveket, ellenérveket. Munkájuk egyaránt műszaki és üzleti szemléletű. Előbb elkülönítik a kvantumkulcscsere hagyományos eljárásokkal szembeni használatának motiváló tényezőit, és megállapítják, milyen körülmények között szükséges a napi működésben alkalmazni. Ezt követően a forgalomban is kapható QKD-termékek tulajdonságait és gyártóit szemügyre véve megfogalmazzák a termék széles körű elterjedésének korlátait. Végül a kvantumkulcscsere-termék bevezetéséről szóló vállalati döntéshozás különböző aspektusait tekintik át. Információbiztonsági és üzleti szempontból összehasonlítják az új, valamint a hagyományosan használt kulcscsereeszközöket. Javaslatot tesznek a védendő információ értékének becslésére, amely a használatbavétel költség-haszon elemzését támaszthatja alá. Ebből levezetve megállapítják, hogy mely szervezetek alkotják a QKD lehetséges célcsoportját. Utolsó lépésként pedig arra keresik a választ, melyik időpont lehet ideális a termék bevezetésére. _____ This study aims to illuminate Quantum Key Distribution (QKD), a new invention that has the potential to bring sweeping changes to information security. The authors’ goal is to present QKD as a product in the field of IT security, and to examine several pro and con arguments regarding the installation of this product. Their work demonstrates both the technical and the business perspectives of applying QKD. First they identify motivational factors of using Quantum Key Distribution over traditional methods. Then the authors assess under which circumstances QKD could be necessary to be used in daily business. Furthermore, to evaluate the limitations of its broad spread, they introduce the vendors and explore the properties of their commercially available QKD products. Bearing all this in mind, they come out with numerous factors that can influence corporate decision making regarding the installation of QKD. The authors compare the traditional and the new tools of key distribution from an IT security and business perspective. They also take efforts to estimate the value of the pieces of information to be protected. This could be useful for a subsequent cost–benefit analysis. Their findings try to provide support for determining the target audience of QKD in the IT security market. Finally the authors attempt to find an ideal moment for an organization to invest in Quantum Key Distribution.
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To carry out their specific roles in the cell, genes and gene products often work together in groups, forming many relationships among themselves and with other molecules. Such relationships include physical protein-protein interaction relationships, regulatory relationships, metabolic relationships, genetic relationships, and much more. With advances in science and technology, some high throughput technologies have been developed to simultaneously detect tens of thousands of pairwise protein-protein interactions and protein-DNA interactions. However, the data generated by high throughput methods are prone to noise. Furthermore, the technology itself has its limitations, and cannot detect all kinds of relationships between genes and their products. Thus there is a pressing need to investigate all kinds of relationships and their roles in a living system using bioinformatic approaches, and is a central challenge in Computational Biology and Systems Biology. This dissertation focuses on exploring relationships between genes and gene products using bioinformatic approaches. Specifically, we consider problems related to regulatory relationships, protein-protein interactions, and semantic relationships between genes. A regulatory element is an important pattern or "signal", often located in the promoter of a gene, which is used in the process of turning a gene "on" or "off". Predicting regulatory elements is a key step in exploring the regulatory relationships between genes and gene products. In this dissertation, we consider the problem of improving the prediction of regulatory elements by using comparative genomics data. With regard to protein-protein interactions, we have developed bioinformatics techniques to estimate support for the data on these interactions. While protein-protein interactions and regulatory relationships can be detected by high throughput biological techniques, there is another type of relationship called semantic relationship that cannot be detected by a single technique, but can be inferred using multiple sources of biological data. The contributions of this thesis involved the development and application of a set of bioinformatic approaches that address the challenges mentioned above. These included (i) an EM-based algorithm that improves the prediction of regulatory elements using comparative genomics data, (ii) an approach for estimating the support of protein-protein interaction data, with application to functional annotation of genes, (iii) a novel method for inferring functional network of genes, and (iv) techniques for clustering genes using multi-source data.
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Insulin signaling is one of the main initiators of adipogenesis, the conversion from pre-adipocyte to adipocyte or lipid droplet. Rab proteins are the master regulator of intracellular trafficking and endosome fusion in endocytosis, making them potential regulators of insulin signaling in adipogenesis. Pre-adipocytes 3T3-Ll cells expressing several Rab5 constructs were used to examine the effect of dehydroleucodine (DhL ), a sesquiterpene lactone isolated from aerial parts of Artemisia douglasiana Besser. The results obtained identify Rab5 deactivation as a key step for adipogenesis by forming signaling endosomes. The addition of DhL significantly inhibited the lipid droplet accumulation in a dose-dependent manner and dramatically attenuated the synthesis of adipogenic transcriptional factors, C/EBPa and PPARy. Activation of AMPKa, Erk and Akt during adipocytic differentiation was not inhibited by treatment with DhL. This data suggest that DhL has an important role in Rab5 dependent adipogenesis by regulating several transcriptional factors including PP ARy expression, which is known to play an essential role during fat formation.
The non-timber forest products sector in nepal : policy issues in plant conservation and utilization
Resumo:
The non-timber forest products (NTFPs) sector in Nepal is being promoted with the concept of sustainable management as articulated by the Convention on Biological Diversity. To promote and regulate this sector, Nepal adopted the Herbs and NTFP Development Policy in 2004. The goal of this thesis was to assess the effectiveness of this policy along with other forestry and natural resource policies in Nepal concerning the conservation and sustainable use of NTFPs. I conducted open-ended semi-structured interviews with 28 key informants in summer 2006 in Nepal where I also collected relevant documents and publications. I did qualitative analysis of data obtained from interviews and document review. The research found many important issues that need to be addressed to promote the NTFP sector as envisioned by the Government of Nepal. The findings of this research will help to further implement the policy and promote the NTFP sector through sustainable management practices.
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Formulated food systems are becoming more sophisticated as demand grows for the design of structural and nutritional profiles targeted at increasingly specific demographics. Milk protein is an important bio- and techno-functional component of such formulations, which include infant formula, sports supplements, clinical beverages and elderly nutrition products. This thesis outlines research into ingredients that are key to the development of these products, namely milk protein concentrate (MPC), milk protein isolate (MPI), micellar casein concentrate (MCC), β-casein concentrate (BCC) and serum protein concentrate (SPC). MPC powders ranging from 37 to 90% protein (solids basis) were studied for properties of relevance to handling and storage of powders, powder solubilisation and thermal processing of reconstituted MPCs. MPC powders with ≥80% protein were found to have very poor flowability and high compressibility; in addition, these high-protein MPCs exhibited poor wetting and dispersion characteristics during rehydration in water. Heat stability studies on unconcentrated (3.5%, 140°C) and concentrated (8.5%, 120°C) MPC suspensions, showed that suspensions prepared from high-protein MPCs coagulated much more rapidly than lower protein MPCs. β-casein ingredients were developed using membrane processing. Enrichment of β-casein from skim milk was performed at laboratory-scale using ‘cold’ microfiltration (MF) at <4°C with either 1000 kDa molecular weight cut-off or 0.1 µm pore-size membranes. At pilot-scale, a second ‘warm’ MF step at 26°C was incorporated for selective purification of micellised β-casein from whey proteins; using this approach, BCCs with β-casein purity of up to 80% (protein basis) were prepared, with the whey protein purity of the SPC co-product reaching ~90%. The BCC ingredient could prevent supersaturated solutions of calcium phosphate (CaP) from precipitating, although the amorphous CaP formed created large micelles that were less thermo-reversible than those in CaP-free systems. Another co-product of BCC manufacture, MCC powder, was shown to have superior rehydration characteristics compared to traditional MCCs. The findings presented in this thesis constitute a significant advance in the research of milk protein ingredients, in terms of optimising their preparation by membrane filtration, preventing their destabilisation during processing and facilitating their effective incorporation into nutritional formulations designed for consumers of a specific age, lifestyle or health status