263 research outputs found

    APPLICATION OF A FUNCTIONAL MATHEMATICAL QUALITY INDEX

    Get PDF
    In this article, we apply a functional mathematical index (FMI), introduced in a previous publication, to 20 commercial potato varieties. The index allows evaluation of nutritional, safety and processing "quality parameters" of different potato cultivars. The main goal of the index is to link the quality of the chemical composition with factors that may affect the growth, production, distribution and processing of potatoes and potato products for commercial use. The index has been used to assess FMI values of 20 commercial potato cultivars in terms of their content of asparagine and reducing sugars, which form heat-induced potentially toxic acrylamide and of antioxidative phenolic compounds, which participate in nonenzymatic browning reactions and may exert beneficial effects after consumption. PRACTICAL APPLICATIONS The index could be useful to a wide set of users, including consumers of potatoes as well as to potato producers and breeders, because it makes it possible to relate the index to the potato price and operate a more accurate choice for selection of so-called "optimal potatoes." Potato producers may find the index useful because it can help them detect the critical points throughout the whole food production chain in order to facilitate selection of high-quality potatoes for sale to consumers. Potato breeders could apply the index to the development and selection of improved cultivars for commercial use

    Effect of pomegranate powder on the heat inactivation of Escherichia coli O104: H4 in ground chicken

    Get PDF
    Health concerns have led to a search for natural plant-based antimicrobials. Ellagic acid has been shown to have antimicrobial activity against foodborne pathogens. The objective of this study was to assess the effect of a high-ellagic acid commercial pomegranate on the heat resistance of Escherichia coli O104:H4 in ground chicken. A full 2 4 factorial design was used, consisting of temperature treatment with four levels (55.0, 57.5, 60.0, and 62.5 °C) and pomegranate with four levels (0.0, 1.0, 2.0, and 3.0 wt/wt. % containing 70% ellagic acid). Experiments were conducted twice, providing a total of 32 survival curves. A three-parameter Weibull primary model was used to describe survival kinetics. Secondary models were then developed to estimate the shape parameter ß (i.e., curvature representing susceptibility of cells to stress), scale parameter ? (i.e., time to reach the first decimal reduction) and the 5.0-log lethality time t 5.0 (i.e., time to reach a 5.0-log reduction), all as polynomial functions of temperature and pomegranate powder concentration. The positive effect of pomegranate concentration on both ß and ? demonstrated that the phenolic-rich pomegranate powder causes E. coli O104:H4 cells to become more susceptible to heat, increasing the steepness and concavity of the isothermal survival curves. It was estimated that the 5.0-log reduction time would reach a minimum at a pomegranate powder concentration of 1%, producing a 50% decrease in lethality time, in comparison to that without added pomegranate powder. Nonetheless, a mixed-effect omnibus regression further confirmed that the greatest difference in the thermal resistance of E. coli O104:H4 happened between tests with and without pomegranate powder. In fact, adding more than 1.0% pomegranate powder, at a constant temperature, resulted only in a marginal decrease in thermal resistance. Meat processors can use the model to design lethality treatments in order to achieve specific reductions of E. coli O104:H4 in ground chicken.We thank Angie Osoria and Carol E. Levin for technical assistance as well as in facilitating the preparation of the manuscript. Also, Dr. Gonzales-Barron wishes to acknowledge the financial support provided by the Portuguese Foundation for Science and Technology (FCT) through the award of a five-year Investigator Fellowship (IF) in the mode of Development Grants (IF/00570).info:eu-repo/semantics/publishedVersio

    Effect of Allyl Isothiocyanate on Developmental Toxicity in Exposed Xenopus Laevis Embryos

    Get PDF
    The pungent natural compound allyl isothiocyanate isolated from the seeds of Cru-ciferous (Brassica) plants such as mustard is reported to exhibit numerous beneficialhealth-promoting antimicrobial, antifungal, anticarcinogenic, cardioprotective, and neu-roprotective properties. Because it is also reported to damage DNA and is toxic to aquaticorganisms, the objective of the present study was to determine whether it possesses tera-togenic properties. The frog embryo teratogenesis assay-Xenopus (FETAX) was used todetermine the following measures of developmental toxicity of the allyl isothiocyanate:(a) 96-h LC50, defined as the median concentration causing 50% embryo lethality; (b) 96-h EC50, defined as the median concentration causing 50% malformations of the survivingembryos; and (c) teratogenic malformation index (TI), equal to 96-h LC50/96-h EC50. Thequantitative results and the photographs of embryos before and after exposure suggest thatallyl isothiocyanate seems to exhibit moderate teratogenic properties. The results also indi-cate differences in the toxicity of allyl isothiocyanate toward exposed embryos observedin the present study compared to reported adverse effects of allyl isothiocyanate in fish,rodents, and humans. The significance of the results for food safety and possible approachesto protect against adverse effects of allyl isothiocyanate are discussed

    Type-2 fuzzy linear systems

    Get PDF
    Fuzzy Linear Systems (FLSs) are used in practical situations where some of the systems parameters or variables are uncertain. To date, investigations conducted on FLSs are restricted to those in which the uncertainty is assumed to be modeled by Type-1 Fuzzy Sets (T1FSs). However, there are many situations where considering the uncertainty as T1FSs may not be possible due to different interpretations of experts about the uncertainty. Moreover, solutions of FLSs are T1FSs which do not provide any information about a measure of the dispersion of uncertainty around the T1FSs. Therefore, in this research a model of uncertain linear equations system called a type-2 fuzzy linear system is presented to overcome the shortcomings. The uncertainty is represented by a special class of type-2 fuzzy sets – triangular perfect quasi type-2 fuzzy numbers. Additionally, conditions for the existence of a unique type–2 fuzzy solution to the linear system are derived. A definition of a type-2 fuzzy solution is also given. The applicability of the proposed model is illustrated using examples in the pulp and paper industry, and electrical engineering

    Petri Nets with Fuzzy Logic (PNFL): Reverse Engineering and Parametrization

    Get PDF
    Background: The recent DREAM4 blind assessment provided a particularly realistic and challenging setting for network reverse engineering methods. The in silico part of DREAM4 solicited the inference of cycle-rich gene regulatory networks from heterogeneous, noisy expression data including time courses as well as knockout, knockdown and multifactorial perturbations. Methodology and Principal Findings: We inferred and parametrized simulation models based on Petri Nets with Fuzzy Logic (PNFL). This completely automated approach correctly reconstructed networks with cycles as well as oscillating network motifs. PNFL was evaluated as the best performer on DREAM4 in silico networks of size 10 with an area under the precision-recall curve (AUPR) of 81%. Besides topology, we inferred a range of additional mechanistic details with good reliability, e.g. distinguishing activation from inhibition as well as dependent from independent regulation. Our models also performed well on new experimental conditions such as double knockout mutations that were not included in the provided datasets. Conclusions: The inference of biological networks substantially benefits from methods that are expressive enough to deal with diverse datasets in a unified way. At the same time, overly complex approaches could generate multiple different models that explain the data equally well. PNFL appears to strike the balance between expressive power and complexity. This also applies to the intuitive representation of PNFL models combining a straightforward graphical notation with colloquial fuzzy parameters

    A genetic cause of Alzheimer disease: mechanistic insights from Down syndrome

    Get PDF
    Down syndrome, caused by an extra copy of chromosome 21, is associated with a greatly increased risk of early onset Alzheimer disease. It is thought that this risk is conferred by the presence of three copies of the gene encoding amyloid precursor protein (APP), an Alzheimer risk factor, although the possession of extra copies of other chromosome 21 genes may also play a role. Further study of the mechanisms underlying the development of Alzheimer disease in Down syndrome could provide insights into the mechanisms that cause dementia in the general population

    Advances in the treatment of prolactinomas

    Get PDF
    Prolactinomas account for approximately 40% of all pituitary adenomas and are an important cause of hypogonadism and infertility. The ultimate goal of therapy for prolactinomas is restoration or achievement of eugonadism through the normalization of hyperprolactinemia and control of tumor mass. Medical therapy with dopamine agonists is highly effective in the majority of cases and represents the mainstay of therapy. Recent data indicating successful withdrawal of these agents in a subset of patients challenge the previously held concept that medical therapy is a lifelong requirement. Complicated situations, such as those encountered in resistance to dopamine agonists, pregnancy, and giant or malignant prolactinomas, may require multimodal therapy involving surgery, radiotherapy, or both. Progress in elucidating the mechanisms underlying the pathogenesis of prolactinomas may enable future development of novel molecular therapies for treatment-resistant cases. This review provides a critical analysis of the efficacy and safety of the various modes of therapy available for the treatment of patients with prolactinomas with an emphasis on challenging situations, a discussion of the data regarding withdrawal of medical therapy, and a foreshadowing of novel approaches to therapy that may become available in the future
    • …
    corecore