77 resultados para Cornell University. School of Civil Engineering.


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The use of macroalgae (seaweed) as a potential source of biofuels has attracted considerable worldwide interest. Since brown algae, especially the giant kelp, grow very rapidly and contain considerable amounts of polysaccharides, coupled with low lignin content, they represent attractive candidates for bioconversion to ethanol through yeast fermentation processes. In the current study, powdered dried seaweeds (Ascophylum nodosum and Laminaria digitata) were pre-treated with dilute sulphuric acid and hydrolysed with commercially available enzymes to liberate fermentable sugars. Higher sugar concentrations were obtained from L. digitata compared with A. nodosum with glucose and rhamnose being the predominant sugars, respectively, liberated from these seaweeds. Fermentation of the resultant seaweed sugars was performed using two non-conventional yeast strains: Scheffersomyces (Pichia) stipitis and Kluyveromyces marxianus based on their abilities to utilise a wide range of sugars. Although the yields of ethanol were quite low (at around 6 g/L), macroalgal ethanol production was slightly higher using K. marxianus compared with S. stipitis. The results obtained demonstrate the feasibility of obtaining ethanol from brown algae using relatively straightforward bioprocess technology, together with non-conventional yeasts. Conversion efficiency of these non-conventional yeasts could be maximised by operating the fermentation process based on the physiological requirements of the yeasts.

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Background Sweet cherries (Prunus avium L.) are a nutritious fruit which are rich in polyphenols and have high antioxidant potential. Most sweet cherries are consumed fresh and a small proportion of the total sweet cherries production is value added to make processed food products. Sweet cherries are highly perishable fruit with a short harvest season, therefore extensive preservation and processing methods have been developed for the extension of their shelf-life and distribution of their products. Scope and Approach In this review, the main physicochemical properties of sweet cherries, as well as bioactive components and their determination methods are described. The study emphasises the recent progress of postharvest technology, such as controlled/modified atmosphere storage, edible coatings, irradiation, and biological control agents, to maintain sweet cherries for the fresh market. Valorisations of second-grade sweet cherries, as well as trends for the diversification of cherry products for future studies are also discussed. Key Findings and Conclusions Sweet cherry fruit have a short harvest period and marketing window. The major loss in quality after harvest include moisture loss, softening, decay and stem browning. Without compromising their eating quality, the extension in fruit quality and shelf-life for sweet cherries is feasible by means of combination of good handling practice and applications of appropriate postharvest technology. With the drive of health-food sector, the potential of using second class cherries including cherry stems as a source of bioactive compound extraction is high, as cherry fruit is well-known for being rich in health-promoting components.

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Animals that fast during breeding and/or development, such as phocids, must regulate energy balance carefully to maximize reproductive fitness and survival probability. Adiponectin, produced by adipose tissue, contributes to metabolic regulation by modulating sensitivity to insulin, increasing fatty acid oxidation by liver and muscle, and promoting adipogenesis and lipid storage in fat tissue. We tested the hypotheses that (1) circulating adiponectin, insulin, or relative adiponectin gene expression is related to nutritional state, body mass, and mass gain in wild gray seal pups; (2) plasma adiponectin or insulin is related to maternal lactation duration, body mass, percentage milk fat, or free fatty acid (FFA) concentration; and (3) plasma adiponectin and insulin are correlated with circulating FFA in females and pups. In pups, plasma adiponectin decreased during suckling (linear mixed-effects model [LME]: T = 4.49; P < 0.001) and the early postweaning fast (LME: T = 3.39; P = 0.004). In contrast, their blubber adiponectin gene expression was higher during the early postweaning fast than early in suckling (LME: T = 2.11; P = 0.046). Insulin levels were significantly higher in early (LME: T = 3.52; P = 0.004) and late (LME: T = 6.99; P < 0.001) suckling than in fasting and, given the effect of nutritional state, were also positively related to body mass (LME: T = 3.58; P = 0.004). Adiponectin and insulin levels did not change during lactation and were unrelated to milk FFA or percentage milk fat in adult females. Our data suggest that adiponectin, in conjunction with insulin, may facilitate fat storage in seals and is likely to be particularly important in the development of blubber reserves in pups.

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Phocid seals have been proposed as models for diabetes because they exhibit limited insulin response to glucose, high blood glucose and increasing insulin resistance when fasting. Liver glucose-6-phosphatase (G6Pase) catalyses the final step in glucose production and is central to glucose regulation in other animals. G6Pase comprises a translocase (SLC37A4) and a catalytic subunit (G6PC). G6PC and SLC37A4 expression and activity are normally regulated by nutritional state and glucostatic hormones, particularly insulin, and are elevated in diabetes. We tested the hypotheses that (1) grey seal G6PC and SLC37A4 cDNA and predicted protein sequences differ from other species’ at functional sites, (2) relative G6Pase protein abundances are lower during feeding than fasting and (3) relative G6Pase protein abundances are related to insulin, insulin receptor phosphorylation and key metabolite levels. We show that G6PC and partial SLC37A4 cDNA sequences encode proteins sharing 82–95 % identity with other mammals. Seal G6PC contained no differences in sites responsible for activity, stability or subcellular location. Several substitutions in seal SLC37A4 were predicted to be tolerated with low probability, which could affect glucose production. Suckling pups had higher relative abundance of both subunits than healthy, postweaned fasting pups. Furthermore, relative G6PC abundance was negatively related to glucose levels. These findings contrast markedly with the response of relative hepatic G6Pase abundance to feeding, fasting, insulin, insulin sensitivity and key metabolites in other animals, and highlight the need to understand the regulation of enzymes involved in glucose control in phocids if these animals are to be informative models of diabetes.

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The cytokine hormone leptin is a key signalling molecule in many pathways that control physiological functions. Although leptin demonstrates structural conservation in mammals, there is evidence of positive selection in primates, lagomorphs and chiropterans. We previously reported that the leptin genes of the grey and harbour seals (phocids) have significantly diverged from other mammals. Therefore we further investigated the diversification of leptin in phocids, other marine mammals and terrestrial taxa by sequencing the leptin genes of representative species. Phylogenetic reconstruction revealed that leptin diversification was pronounced within the phocid seals with a high dN/dS ratio of 2.8, indicating positive selection. We found significant evidence of positive selection along the branch leading to the phocids, within the phocid clade, but not over the dataset as a whole. Structural predictions indicate that the individual residues under selection are away from the leptin receptor (LEPR) binding site. Predictions of the surface electrostatic potential indicate that phocid seal leptin is notably different to other mammalian leptins, including the otariids. Cloning the grey seal leptin binding domain of LEPR confirmed that this was structurally conserved. These data, viewed in toto, support a hypothesis that phocid leptin divergence is unlikely to have arisen by random mutation. Based upon these phylogenetic and structural assessments, and considering the comparative physiology and varying life histories among species, we postulate that the unique phocid diving behaviour has produced this selection pressure. The Phocidae includes some of the deepest diving species, yet have the least modified lung structure to cope with pressure and volume changes experienced at depth. Therefore, greater surfactant production is required to facilitate rapid lung re-inflation upon surfacing, while maintaining patent airways. We suggest that this additional surfactant requirement is met by the leptin pulmonary surfactant production pathway which normally appears only to function in the mammalian foetus.

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How rainfall infiltration rate and soil hydrological characteristics develop over time under forests of different ages in temperate regions is poorly understood. In this study, infiltration rate and soil hydrological characteristics were investigated under forests of different ages and under grassland. Soil hydraulic characteristics were measured at different scales under a 250-year-old grazed grassland (GL), 6-year-old (6yr) and 48-year-old (48yr) Scots pine (Pinus sylvestris) plantations, remnant 300-year-old individual Scots pine (OT) and a 4000-year-old Caledonian Forest (AF). In situ field-saturated hydraulic conductivity (Kfs) was measured, and visible root:soil area was estimated from soil pits. Macroporosity, pore structure and macropore connectivity were estimated from X-ray tomography of soil cores, and from water-release characteristics. At all scales, the median values for Kfs, root fraction, macroporosity and connectivity values tended to AF>OT>48yr>GL>6yr, indicating that infiltration rates and water storage increased with forest age. The remnant Caledonian Forest had a huge range of Kfs (12 to >4922mmh-1), with maximum Kfs values 7 to 15 times larger than those of 48-year-old Scots pine plantation, suggesting that undisturbed old forests, with high rainfall and minimal evapotranspiration in winter, may act as important areas for water storage and sinks for storm rainfall to infiltrate and transport to deeper soil layers via preferential flow. The importance of the development of soil hydrological characteristics under different aged forests is discussed.

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The Green Deal (GD) was launched in 2013 by the UK Government as a market-led scheme to encourage uptake of energy efficiency measures in the UK and create green sector jobs. The scheme closed in July 2015 after 30 months due to government concerns over low uptake and industry standards but additional factors potentially contributed to its failure such as poor scheme design and lack of understanding of the customer and supply chain journey. We explore the role of key delivery agents of GD services, specifically SMEs, and we use the LoCal-Net project as a case study to examine the use of networks to identify and reduce barriers to SME market engagement. We find that SMEs experienced multiple barriers to interaction with the GD such as lack of access to information, training, and confusion over delivery of the scheme but benefited from interaction with the network to access information, improve understanding of the scheme, increasing networking opportunities and forming new business models and partnerships to reduce risk. The importance of SMEs as delivery agents and their role in the design of market-led schemes such as the GD are discussed with recommendations for improving SME engagement in green sector initiatives.

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Introduction The Scottish Oral Health Research Collaboration identified dental education research (DER) as a key strand of their strategy,(1) leading to the formation of the Dental Education Research Group. The starting point for this group was to understand various stakeholders’ perceptions of research priorities, yet no existing studies were found. The aim of the current study was to identify DER priorities for Scotland in the next 3-5 years. Methods The study utilised a similar methodology to that of Dennis et al,(2) in medical education. Data were collected sequentially using two online questionnaires with multiple dental stakeholders represented at undergraduate and postgraduate levels across urban and rural Scotland. 85 participants completed questionnaire 1 (qualitative) and 649 participants completed questionnaire 2 (quantitative). Qualitative and quantitative data analysis approaches were used. Results Of the 24 priorities identified, the top priorities were: role of assessments in identifying competence; undergraduate curriculum prepares for practice; and promoting teamwork within the dental team. Following factor analysis, the priorities loaded on four factors: teamwork and professionalism, measuring and enhancing performance, personal and professional development challenges, and curriculum integration and innovation. The top barriers were lack of time, funding, staff motivation, valuing of DER, and resources/ infrastructure. Discussion There were many similarities between the identified priorities for dental and medical education research2, but also some notable differences, which will be discussed. Overwhelmingly, the identified priorities in dentistry related to fitness for practice and robust assessment practices. Take home message Priority setting exercises with multiple stakeholders are an important first step in developing a national research strategy. References 1. Bagg J, Macpherson L, Mossey P, Rennie J, Saunders B, Taylor M (2010) Strategy for Oral Health Research in Scotland. Edinburgh: The Scottish Government. 2. Dennis A A, Cleland J A, Johnston P, Ker JS, Lough, M Rees CE (2014) Exploring stakeholders’ views of medical education research priorities: a national study. Medical Education, 48(11): 1078-1091.

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Construction management research literature has identified the importance of understanding the practical realities of skills and training provision and the role of reflective practice in the development of knowledge. This paper examines vocational training of experienced site staff in the development of their knowledge through SVQ training to investigate the primary factors for successful learning in site-based construction staff with a supervisory/management role. Using semi-structured interviews the impact of vocational training on individual candidates and other sitebased staff are investigated. The paper explores, through the reflections of 26 SVQ candidates (20 SVQ3 and 6 SVQ4), a deeper understanding of how site supervisors and site managers learn through the SVQ process and develop tacit knowledge through formal reflection. Reflective practice develops practical wisdom (Phronesis). The investigation explains aspects of practical wisdom and how knowledge, practice and skills are developed through vocational training. There is a clear perception by those completing the qualification that it has enabled them to perform their job better identifying numerous examples relating to problem solving, critical thinking, making decisions and leadership. It has been found that Phronesis is evident on a day-to-day basis on site activities developed through reflective practice in personal development. The reflective practice in developing knowledge also builds, within individuals, a better understanding of themselves and their capabilities through the learning achieved in the SVQ. Future work is identified around analysing the role of the assessor in facilitating Phronesis in the SVQ context.

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Designing for users rather than with users is still a common practice in technology design and innovation as opposed to taking them on board in the process. Design for inclusion aims to define and understand end-users, their needs, context of use, and, by doing so, ensure that end-users are catered for and included, while the results are geared towards universality of use. We describe the central role of end-user and designer participation, immersion and perspective to build user-driven solutions. These approaches provided a critical understanding of the counterpart role. Designer(s) could understand what the user’s needs were, experience physical impairments, and see from other’s perspective the interaction with the environment. Users could understand challenges of designing for physical impairments, build a sense of ownership with technology and explore it from a creative perspective. The understanding of the peer’s role (user and designer), needs and perspective enhanced user participation and inclusion.

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This is an abstract of a presented talk at the European Biotechnology Conference held in Latvia during 05–07 May 2016

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Students may need explicit training in informal statistical reasoning in order to design experiments or use formal statistical tests effectively. By using scientific scandals and media misinterpretation, we can explore the need for good experimental design in an informal way. This article describes the use of a paper that reviews the measles mumps rubella vaccine and autism controversy in the UK to illustrate a number of threshold concepts underlying good study design and interpretation of scientific evidence. These include the necessity of sufficient sample size, representative and random sampling, appropriate controls and inferring causation.

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Human radiosensitivity is a quantitative trait that is generally subject to binomial distribution. Individual radiosensitivity, however, may deviate significantly from the mean (by 2-3 standard deviations). Thus, the same dose of radiation may result in different levels of genotoxic damage (commonly measured as chromosome aberration rates) in different individuals. There is significant genetic component in individual radiosensitivity. It is related to carriership of variant alleles of various single-nucleotide polymorphisms (most of these in genes coding for proteins functioning in DNA damage identification and repair); carriership of different number of alleles producing cumulative effects; amplification of gene copies coding for proteins responsible for radioresistance, mobile genetic elements, and others. Among the other factors influencing individual radioresistance are: radioadaptive response; bystander effect; levels of endogenous substances with radioprotective and antimutagenic properties and environmental factors such as lifestyle and diet, physical activity, psychoemotional state, hormonal state, certain drugs, infections and others. These factors may have radioprotective or sensibilising effects. Apparently, there are too many factors that may significantly modulate the biological effects of ionising radiation. Thus, conventional methodologies for biodosimetry (specifically, cytogenetic methods) may produce significant errors if personal traits that may affect radioresistance are not accounted for.

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As mechatronic devices and components become increasingly integrated with and within wider systems concepts such as Cyber-Physical Systems and the Internet of Things, designer engineers are faced with new sets of challenges in areas such as privacy. The paper looks at the current, and potential future, of privacy legislation, regulations and standards and considers how these are likely to impact on the way in which mechatronics is perceived and viewed. The emphasis is not therefore on technical issues, though these are brought into consideration where relevant, but on the soft, or human centred, issues associated with achieving user privacy.