2,087 research outputs found

    Cloning and high-level production of a chitinase from Chromobacterium sp. and the role of conserved or nonconserved residues on its catalytic activity

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    A gene encoding an alkaline (pI of 8.67) chitinase was cloned and sequenced from Chromobacterium sp. strain C-61. The gene was composed of 1,611 nucleotides and encoded a signal sequence of 26N-terminal amino acids and a mature protein of 510 amino acids. Two chitinases of 54 and 52kDa from both recombinant Escherichia coli and C-61 were detected on SDS-PAGE. Maximum chitinase activity was obtained in the culture supernatant of recombinant E. coli when cultivated in TB medium for 6days at 37°C and was about fourfold higher than that from C-61. Chi54 from the culture supernatants could be purified by a single step based on isoelectric point. The purified Chi54 had about twofold higher binding affinity to chitin than to cellulose. The chi54 encoded a protein that included a type 3 chitin-binding domain belonging to group A and a family 18 catalytic domain belonging to subfamily A. In the catalytic domain, mutation of perfectly conserved residues and highly conserved residues resulted in loss of nearly all activity, while mutation of nonconserved residues resulted in enzymes that retained activity. In this process, a mutant (T218S) was obtained that had about 133% of the activity of the wild type, based on comparison of K cat value

    Mentalisation Amongst Maternal and Child Health Nurses Using the Newborn Behavioural Observations With Infant-mother dyads: A Qualitative Study

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    © 2020 Elsevier Inc. Purpose: This study explored Maternal and Child Health Nurses\u27 (MCHN) mentalisation processes towards infant-mother dyads when using the Newborn Behavioural Observations (NBO) system in practice. Design and methods: Ten Australian MCHNs (female; aged 31–66 years), who had used the NBO clinically within the last 12 months, were recruited from a database of NBO-trained practitioners. Interpretative phenomenological analysis of one-on-one semi-structured interviews explored MCHNs experiential meaning-making. Results: Analysis of the data produced four main themes: reflections regarding the dyad, personal reflections, reflection into action, and professional identity and future practice. MCHNs reported that the NBO\u27s focus on the pre-verbal infant provided them with an added dynamic to consultations outside of the practitioner-caregiver relationship. Thus, they were able to provide holistic and collaborative relationship support to infant-mother dyads. Emotional satisfaction and pride in profession were also reported; in current literature, these factors have been found to reduce burnout in primary care providers. Conclusions: The NBO appears to promote practitioner mentalisation, offering MCHNs a framework and confidence to apply infant mental health theory practically. Practice implications: The NBO offers potential benefits to child and family health nursing practice, and other primary care providers, who offer infant mental health and relationship support as part of their work with families in the first three months. The NBO also provides a means to shift from prescriptive to mentalisation-based, infant-inclusive, and individualised practice

    Can we Improve how we Diagnose Osteomyelitis in the Diabetic Foot?

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    Soft tissue infection in a diabetic foot with an ulcer is often clinically obvious but the diagnosis of osteomyelitis underlying a diabetic foot ulcer is challenging. It has been calculated that there are over 1 million amputations worldwide for diabetes related complications every year, many preceded by an ulcer complicated by osteomyelitis. This research encompasses two studies attempting to add to the ways in which osteomyelitis is diagnosed. The first was examining the role of inflammatory blood markers in recognising and separating ulcers with cutaneous infection from both suspected and proven osteomyelitis. The response of the body to produce these markers when an injury occurs is well known but arguments exist as to the capacity of the individual with diabetes to do so. Despite the recognition and allowance for common confounding factors no trend was found. This study may have been more difficult than originally thought due to the many interactions of the diseased state of diabetes, the drugs used to control it and the many other confounders that would have influenced the inflammatory process and as such the level of the markers. The second study was comparing a new form of scanning technique (SPECT/CT) to the technique most commonly used as a ‘gold standard’ – MRI. The results of each type of scan were compared to the clinical diagnosis and each other. The SPECT/CT scan appears to show some good results and may be a more suitable scan for individuals who are unable to have a MRI for example due to the need to introduce a renally excreted drug to help make the images clearer but it does mean introducing a small amount of radiation into the individual.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

    Effect of changing data size on eigenvalues in the Korean and Japanese stock markets

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    In this study, we attempted to determine how eigenvalues change, according to random matrix theory (RMT), in stock market data as the number of stocks comprising the correlation matrix changes. Specifically, we tested for changes in the eigenvalue properties as a function of the number and type of stocks in the correlation matrix. We determined that the value of the eigenvalue increases in proportion with the number of stocks. Furthermore, we noted that the largest eigenvalue maintains its identical properties, regardless of the number and type, whereas other eigenvalues evidence different features

    Deterministic Factors of Stock Networks based on Cross-correlation in Financial Market

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    The stock market has been known to form homogeneous stock groups with a higher correlation among different stocks according to common economic factors that influence individual stocks. We investigate the role of common economic factors in the market in the formation of stock networks, using the arbitrage pricing model reflecting essential properties of common economic factors. We find that the degree of consistency between real and model stock networks increases as additional common economic factors are incorporated into our model. Furthermore, we find that individual stocks with a large number of links to other stocks in a network are more highly correlated with common economic factors than those with a small number of links. This suggests that common economic factors in the stock market can be understood in terms of deterministic factors.Comment: 4 pages, 1 figur

    Cornell Realism, Explanation, and Natural Properties

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    The claim that ordinary ethical discourse is typically true and that ethical facts are typically knowable seems in tension with the claim that ordinary ethical discourse is about features of reality friendly to a scientific worldview. Cornell Realism attempts to dispel this tension by claiming that ordinary ethical discourse is, in fact, discourse about the same kinds of things that scientific discourse is about: natural properties. We offer two novel arguments in reply. First, we identify a key assumption that we find unlikely to be true. Second, we identify two features of typical natural properties that ethical properties lack. We conclude that Cornell Realism falls short of dispelling the tension between ethical conservativism and ethical naturalism
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