30 research outputs found

    Fractal Behavior in the Clarification Process of Cane Sugar Production

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    Cane sugar production is an important industrial process. One of the most important steps in cane sugar production is the clarification process, which provides high-quality, concentrated sugar syrup crystal for further processing. To gain fundamental understanding of the physical and chemical processes associated with the clarification process and help design better approaches to improve the clarification of the mixed juice, we explore the fractal behavior of the variables pertinent to the clarification process. We show that the major variables in this key process all show persistent long-range correlations, for time scales up to at least a few days. Persistent long-range correlations amount to unilateral deviations from a preset target. This means that when the process is in a desired mode such that the target variables, color of the produced sugar and its clarity degree, both satisfy preset conditions, they will remain so for a long period of time. However, adversity could happen, in the sense that when they do not satisfy the requirements, the adverse situation may last quite long. These findings have to be explicitly accounted for when designing active controlling strategies to improve the quality of the produced sugar

    Characterisation of sucrose synthase activity in the sugarcane culm

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    Dissertation (PhD)--University of Stellenbosch, 2004.ENGLISH ABSTRACT: This study had three main goals: 1. to investigate the occurrence on the protein level of sucrose synthase (SuSy) isoforms in sugarcane sink tissue, 2. to determine the kinetic properties of these isoforms, 3. to establish the tissue localisation of SuSy in the sugarcane culm The results are summarised below: Three SuSy isoforms were obtained from leaf roll tissue. The SuSyA and SuSyB isoforms differed in terms of charge characteristics, with SuSyA not binding to an anion exchange column that bound SuSyB and SuSyC under the same conditions. Both SuSyB and SuSyC isoforms were eluted at 180 mM KCl. The SuSyA and SuSyB isoforms were present during autumn, but during winter only the SuSyC isoform could be isolated. Even though they eluted at the same salt concentration, SuSyB and SuSyC were different isoforms, because they had different kinetic parameters, as well as different immunological properties. SuSyB and SuSyC could not have been mixtures of the same isoforms, since a polyclonal antiserum against SuSyB, which inactivates native SuSyB, did not inactivate SuSyC. All three isoforms had significantly different kinetic parameters, with the SuSyA isoform also having a much lower sucrose breakdown/synthesis ratio than the other two isoforms. Therefore, at least three SuSy isoforms occur in sugarcane leaf roll tissue on the protein level. The SuSyC isoform was subsequently kinetically characterised in detail. Data showed that the enzyme employs an ordered ternary complex mechanism, with UDP binding first and UDP-glucose dissociating last. These experimentally obtained kinetic parameters were then used to extend a kinetic model of sucrose accumulation. Data show that when the experimentally determined SuSy kineticparameters were entered into the model, a 40 % increase in sucrose concentration and 7 times reduction in fructose concentration resulted. These data illustrate the pronounced physiological effects that may result from the presence of different SuSy isoforms. SuSy protein localisation data, obtained by an immunohistochemical approach, indicated that SuSy protein was present in both storage parenchyma and vascular tissue of young, intermediate, and mature internodes. SuSy enzyme activity in different parts of the internodes was similar, except for internode 3, which had much higher activity in the bottom part of the internode, possibly because growth is faster here, hence a higher demand for sucrose cleavage exists here.AFRIKAANSE OPSOMMING: Hierdie studie het ten doel gehad: 1. om die teenwoordigheid van sukrose sintase (SuSy) isovorme in suikkerriet swelgweefsel te ondersoek 2. om die kinetiese eienskappe van hierdie isovorme te ondersoek 3. om die weefsellokalisering van SuSy in die suikerrietstingel te bepaal Die resultate word hieronder opgesom: Drie SuSy isovorme is gevind in blaarrol weefsel. Die SuSyA en SuSyB isovorme het verskil in terme van ladingseienskappe, met SuSyA wat nie aan ‘n anioonuitruilkolom gebind het nie waaraan SuSyB en SuSyC wel onder dieselfde kondisies gebind het. Beide SuSyB en SuSyC isovorme is geĂ«lueer van die kolom teen 180 mM KCl. Die SuSyA en SuSyB isovorme was teenwoordig gedurende herfs, maar in die winter was slegs SuSyC teenwoordig. Ten spyte van die feit dat SuSyB en SuSyC teen dieselfde soutkonsentrasie geĂ«lueer is, het hulle verskillende isovorme verteenwoordig, aangesien hulle kinetiese en immunologiese eienskappe verskil het. SuSyB en SuSyC kon nie mengsels van dieselfde isovorme gewees het nie, want ‘n poliklonale antiserum teen SuSyB, wat SuSyB geĂŻnaktiveer het, het nie SuSyC geĂŻnaktiveer nie. Al drie isovorme het betekenisvol verskil wat kinetiese eienskappe betref, met die SuSyA isovorm wat ook ‘n baie laer sukrose afbraak/sintese verhouding gehad het as die ander twee isovorme. Daar is dus ten minste drie SuSy isovorme teenwoordig op die proteĂŻen vlak in suikerriet blaarrol weefsel. Die in-detail kinetiese analise van die SuSyC isovorm het getoon dat die ensiem ‘n geordende drietallige kompleks meganisme het, met UDP wat eerste bind en UDP-glukose wat laaste dissosieer. Die eksperimenteel bepaalde kinetiese parameters is toe gebruik om ‘n kinetiese model van sukrose akkumulering uit tebrei. Data het getoon dat wanneer die generiese SuSy kinetiese parameters in die oorspronklike model vervang word met die eksperimenteel bepaalde waardes, die berekende sukrose konsentrasie met ongeveer 40 % toeneem, terwyl die fruktose konsentrasie ongeveer 7 keer afneem. Hierdie resultaat toon die groot fisiologiese effek wat die uitdrukking van verskillende SuSy isovorme op suikermetabolisme kan hĂȘ. Die SuSy proteĂŻen lokaliseringsdata, wat met ‘n immunohistochemiese benadering verkry is, het aangedui dat SuSy in beide bergingsparenchiemselle sowel as vaatweefsel teenwoordig is in jong, intermediĂȘre en volwasse internodes. SuSy ensiemaktiwiteit in verskillende dele van die internodes was soortgelyk, behalwe in internode 3, wat baie hoĂ«r aktiwiteit gehad het in die onderste deel van die internode as bo, moontlik weens vinniger groei in hierdie deel van die internode, wat afhanklik is van afbraakprodukte van sukrose

    Alternative protein sources for organic poultry

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    Proceedings of the 10th International Chemical and Biological Engineering Conference - CHEMPOR 2008

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    This volume contains full papers presented at the 10th International Chemical and Biological Engineering Conference - CHEMPOR 2008, held in Braga, Portugal, between September 4th and 6th, 2008.FC

    Functional Foods and their Implications for Health Promotion

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    Functional Foods and Their Implications for Health Promotion presents functional foods, from raw ingredients to the final product, providing a detailed explanation on how these foods work and an overview of their impact on health. The book presents the functions of food against disease and discusses how healthier foods can be produced. Broken into four parts, the book presents a deep dive into plant-derived functional foods, dairy foods, marine food and beverages. The book includes case studies, applications, literature reviews and coverage of recent developments. Intended for nutritionists, dieticians, food technologists, as well as students and researchers working in nutrition, dietetics, and food science, this book is sure to be a welcomed resource

    An Evaluation of Medication Safety related Communications in the Patient Healthcare Pathway in Kuwait

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    Background: Patient safety is a recognised public health issue. When post-market medication safety information emerges, the benefits and risks of the medication concerned are usually evaluated by drug regulatory agencies. The outcomes of such pharmacovigilance activities are communicated to the public, patients and other healthcare professionals (HCPs). The aim of these medication safety communications might vary from improving the intended recipients’ knowledge or attitudes to outlining specific actions to be followed by them. However, it is currently recognised that sharing medication-related information does not improve patients’ safety on its own if not accompanied by an accurate implementation of these recommendations in clinical practice. Despite their importance in protecting patient safety and subsequently affecting public health, no previous study was found to have evaluated or described the process of creating and disseminating medication safety communications by the Kuwaiti drug regulatory agency. Equally, no study was found to have investigated the impact of or the factors affecting the implementation of regulatory-related medication safety communications in Kuwait. Therefore, this thesis aimed to address these gaps in knowledge by evaluating medication safety communications in the patient healthcare pathway in Kuwait. Methods: This multiphase study was preceded by a systematic literature review of the factors affecting HCPs’ implementation of regulatory-related medication safety communications, using a narrative synthesis approach. Following the systematic review, multiphase research was initiated. This consisted of three phases, each of which focused on a specific stakeholder group involved in the process of medication safety communication. Phase 1 involved Kuwait Drug and Food Control (KDFC), an administration within the Ministry of Health (MOH), as the regulatory agency responsible for pharmacovigilance activities. This was a convergent mixed-methods study. Data collection in this phase included documents produced by KDFC or issued to KDFC relating to medication safety and three face-to-face interviews with KDFC employees involved in pharmacovigilance activities. Documents were analysed using a descriptive quantitative approach and a framework analysis technique. Phase 2 focused on healthcare professionals working in MOH hospitals in Kuwait. This phase was an exploratory mixed-methods study, where focus group discussions were conducted followed by the distribution of an online survey. The focus group discussions were analysed using a thematic analysis technique. In the second part of this phase, an online survey was developed based on Phase 1, the focus group discussions and the systematic literature review. Survey data analysis included descriptive analysis (frequency and percentile) and statistical analysis including principal component analysis (PCA) and the Kruskal–Wallis H test, which was followed by a post hoc analysis of variables that had significant results. Other statistical tests applied included Fisher’s exact test, the Mann–Whitney U Test, and multivariate regression analysis. Participants’ answers to open-ended survey questions were analysed using a conventional content analysis technique. Phase 3 was an interpretive phenomenology study. This phase involved semi-structured phone interviews with six female patients of childbearing age who used a valproate-related medication for epilepsy or migraine. These patients had been prescribed the valproate-related medication in one of six secondary hospitals and one specialist neurology hospital within the MOH hospitals. An interpretive phenomenological analysis technique was applied to analyse the transcripts. Results: The results of the systematic literature review indicated that the factors affecting HCPs’ implementation of medication safety communications occur at multiple levels. These levels included the sources or senders of the safety information (delays in the delivery of medications safety communications), healthcare institutions (hospitals’ position and interpretations of the recommendations), the HCPs (knowledge of the content of medications safety communications), and the patients and/or their carers (willingness to use the medication concerned). Phase 1 revealed a lack of legislation and a pharmacovigilance-specific policy. Results from Phase 2 reflected poor knowledge of the concept of medication safety communications within the context of pharmacovigilance and a lack of familiarity with the tools used by KDFC to communicate emerging medication information among HCPs. In the survey, although the majority of HCPs who responded were aware of the teratogenicity of VRM (65.1%, (n = 110/169)), only 2.6% had responded correctly to the statements of the VRM KDFC recommendations. More than half of the participants (57%) reported changing their practice to accommodate at least one intended KDFC recommendation. Providing female patients with written information (37.2%) and counselling female patients about contraceptive use (37.2%) were the most reported intended changes in practice. The most reported barriers to implementation included not having the capacity in terms of time and/or the infrastructure to implement the recommendations (33.8%). Four themes originating from patient interviews included (1) the timeline of the patient’s experience (2) varied knowledge and perception with valproate use, (3) patient’s expectations from HCPs and (4) experiences and preferences towards medication safety communications. Conclusion: Medication safety communications are essential tools for disseminating information related to medication safety updates to HCPs, patients and the public. This research identified challenges at the level of the sender (KDFC) and the intended recipients (HCPs and patients) that could reduce the ability of KDFC’s medication safety communications to reach clinical practices. The first step in increasing their reach is to adapt electronic methods for disseminating such information. Involving stakeholders, such as HCPs and patients, in evaluating the clarity and understandability of KDFC’s medication safety communications should be the focus of future research

    Smoking and Second Hand Smoking in Adolescents with Chronic Kidney Disease: A Report from the Chronic Kidney Disease in Children (CKiD) Cohort Study

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    The goal of this study was to determine the prevalence of smoking and second hand smoking [SHS] in adolescents with CKD and their relationship to baseline parameters at enrollment in the CKiD, observational cohort study of 600 children (aged 1-16 yrs) with Schwartz estimated GFR of 30-90 ml/min/1.73m2. 239 adolescents had self-report survey data on smoking and SHS exposure: 21 [9%] subjects had “ever” smoked a cigarette. Among them, 4 were current and 17 were former smokers. Hypertension was more prevalent in those that had “ever” smoked a cigarette (42%) compared to non-smokers (9%), p\u3c0.01. Among 218 non-smokers, 130 (59%) were male, 142 (65%) were Caucasian; 60 (28%) reported SHS exposure compared to 158 (72%) with no exposure. Non-smoker adolescents with SHS exposure were compared to those without SHS exposure. There was no racial, age, or gender differences between both groups. Baseline creatinine, diastolic hypertension, C reactive protein, lipid profile, GFR and hemoglobin were not statistically different. Significantly higher protein to creatinine ratio (0.90 vs. 0.53, p\u3c0.01) was observed in those exposed to SHS compared to those not exposed. Exposed adolescents were heavier than non-exposed adolescents (85th percentile vs. 55th percentile for BMI, p\u3c 0.01). Uncontrolled casual systolic hypertension was twice as prevalent among those exposed to SHS (16%) compared to those not exposed to SHS (7%), though the difference was not statistically significant (p= 0.07). Adjusted multivariate regression analysis [OR (95% CI)] showed that increased protein to creatinine ratio [1.34 (1.03, 1.75)] and higher BMI [1.14 (1.02, 1.29)] were independently associated with exposure to SHS among non-smoker adolescents. These results reveal that among adolescents with CKD, cigarette use is low and SHS is highly prevalent. The association of smoking with hypertension and SHS with increased proteinuria suggests a possible role of these factors in CKD progression and cardiovascular outcomes
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