835 resultados para sampling methodology


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This study aims to optimize an alternative method of extraction of carrageenan without previous alkaline treatment and ethanol precipitation using Response Surface Methodology (RSM). In order to introduce an innovation in the isolation step, atomization drying was used reducing the time for obtaining dry carrageenan powder. The effects of extraction time and temperature on yield, gel strength, and viscosity were evaluated. Furthermore, the extracted material was submitted to structural analysis, by infrared spectroscopy and nuclear magnetic resonance spectroscopy (¹H-NMR), and chemical composition analysis. Results showed that the generated regression models adequately explained the data variation. Carrageenan yield and gel viscosity were influenced only by the extraction temperature. However, gel strength was influenced by both, extraction time and extraction temperature. Optimal extraction conditions were 74 ºC and 4 hours. In these conditions, the carrageenan extract properties determined by the polynomial model were 31.17%, 158.27 g.cm-2, and 29.5 cP for yield, gel strength, and viscosity, respectively, while under the experimental conditions they were 35.8 ± 4.68%, 112.50 ± 4.96 g.cm-2, and 16.01 ± 1.03 cP, respectively. The chemical composition, nuclear magnetic resonance spectroscopy, and infrared spectroscopy analyses showed that the crude carrageenan extracted is composed mainly of κ-carrageenan.

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"La Niora" is a red pepper variety cultivated in Tadla Region (Morocco) which is used for manufacturing paprika after sun drying. The paprika quality (nutritional, chemical and microbiological) was evaluated immediately after milling, from September to December. Sampling time mainly affected paprika color and the total capsaicinoid and vitamin C contents. The commercial quality was acceptable and no aflatoxins were found, but the microbial load sometimes exceeded permitted levels.

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Assessing fish consumption is complex and involves several factors; however, the use of questionnaires in surveys and the use of the Internet as tool to collect data have been considered promising approaches. Therefore, the objective of this research was to design a data collection technique using a questionnaire to assess fish consumption by making it available on a specific home page on the Internet. A bibliographical survey or review was carried out to identify the features of the instrument, and therefore pre-tests were conducted with previous instruments, followed by the Focus Group technique. Specialists then performed an analysis and conducted an online pre-test. Multivariate data analysis was applied using the SmartPLS software. The results indicate that 1.966 participants belonging to the University of São Paulo (USP) community participated in the test, and after the exclusion of some variables, a statistically significant results were obtained. The final constructs comprised consumption, quality, and general characteristics. The instrument consisted of behavioral statements in a 5-point Likert scale and multiple-choice questions. The Cronbach's alpha reliability coefficient was 0.66 for general characteristics, 0.98 for quality, and 0.91 for consumption, which indicate good reliability of the instrument. In conclusion, the results proved that the Internet assessment is efficient. The instrument of analysis allowed us to better understand the process of buying and consuming fish in the country, and it can be used as base for further research.

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The objective of this study was to evaluate the applicability of the Petrifilm™ plates to enumerate microbial groups in sheep milk. Samples of sheep milk (n = 30) were plated simultaneously, to enumerate mesophilic aerobes, total coliforms, lactic acid bacteria, Staphylococcus aureus and Escherichia coli, using convencional reference protocols and Petrifilm™ plates. The results were compared using McNemar's test, linear regression and ANOVA (p < 0,05). The results demonstrated good significant between conventional methodologies and Petrifilm™ plates. Further, the Petrifim™ STX for counting S. aureus had higher recoverability of bacteria compared with the conventional methodology. Based on the results obtained and in view of the ease and rapidity procedures results, Petrifim ™ plates may be considered as alternatives for microbiological testing in sheep milk.

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AbstractOptimization of microwave drying conditions of Luvhele and Mabonde banana varieties were studied using response surface methodology. The drying was performed using a central composite rotatable design for two variables: microwave power level (100, 200 and 300 W) and drying time (40, 26, and 12 min.) for Luvhele; (100, 200 and 300 W) and (42, 27, and 12 min) for Mabonde. The colour and texture (hardness) data were analyzed using ANOVA and regression analysis. The fitness of the models obtained was good as the lack of fit for each of the models was not significant. The coefficient of determination R2 of the models was relatively high, hence the models obtained for the responses were adequate and acceptable. Drying conditions of 178.76 W, 12 min. drying time were found optimum for product quality at a desirability of 0.91 for Luvhele; while 127.67 W, 12 min. with a desirability of 0.86 was predicted for Mabonde. The result of this study could be used as a standard for microwave processing of Luvhele and Mabondebanana varieties.

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Abstract Caprine Coalho cheese presents great potential for a typical protected designation of origin, considering that this traditional Brazilian cheese presents a slightly salty and acid flavor, combined with a unique texture. This study optimized the HS-SPME-GC-MS methodology for volatile analysis of Coalho cheese, which can be used as a tool to help in the identification of the distinctive aroma profile of this cheese. The conditions of equilibrium time, extraction temperature and time were optimized using the statistical tool factorial experimental design 23, and applying the desirability function. After the evaluation, it was concluded that the optimum extraction conditions comprised equilibrium and extraction time of 20 and 40 minutes, respectively; and ideal extraction temperature of 45 °C. The optimum extraction of volatile compounds in goat Coalho cheese captured 32 volatile compounds: 5 alcohols, 5 esters, 3 ketones, 6 acids, 3 aldehydes, 3 terpenes, and 7 hydrocarbons.

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Introduction: The chronic kidney disease outcomes and practice patterns study (CKDopps) is an international observational, prospective, cohort study involving patients with chronic kidney disease (CKD) stages 3-5 [estimated glomerular filtration rate (eGFR) < 60 ml/min/1.73 m2, with a major focus upon care during the advanced CKD period (eGFR < 30 ml/min/1.73 m2)]. During a 1-year enrollment period, each one of the 22 selected clinics will enroll up to 60 advanced CKD patients (eGFR < 30 ml/min/1.73 m2 and not dialysis-dependent) and 20 earlier stage CKD patients (eGFR between 30-59 ml/min/1.73 m2). Exclusion criteria: age < 18 years old, patients on chronic dialysis or prior kidney transplant. The study timeline include up to one year for enrollment of patients at each clinic starting in the end of 2013, followed by up to 2-3 years of patient follow-up with collection of detailed longitudinal patient-level data, annual clinic practice-level surveys, and patient surveys. Analyses will apply regression models to evaluate the contribution of patient-level and clinic practice-level factors to study outcomes, and utilize instrumental variable-type techniques when appropriate. Conclusion: Launching in 2013, CKDopps Brazil will study advanced CKD care in a random selection of nephrology clinics across Brazil to gain understanding of variation in care across the country, and as part of a multinational study to identify optimal treatment practices to slow kidney disease progression and improve outcomes during the transition period to end-stage kidney disease.

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The number of security violations is increasing and a security breach could have irreversible impacts to business. There are several ways to improve organization security, but some of them may be difficult to comprehend. This thesis demystifies threat modeling as part of secure system development. Threat modeling enables developers to reveal previously undetected security issues from computer systems. It offers a structured approach for organizations to find and address threats against vulnerabilities. When implemented correctly threat modeling will reduce the amount of defects and malicious attempts against the target environment. In this thesis Microsoft Security Development Lifecycle (SDL) is introduced as an effective methodology for reducing defects in the target system. SDL is traditionally meant to be used in software development, principles can be however partially adapted to IT-infrastructure development. Microsoft threat modeling methodology is an important part of SDL and it is utilized in this thesis to find threats from the Acme Corporation’s factory environment. Acme Corporation is used as a pseudonym for a company providing high-technology consumer electronics. Target for threat modeling is the IT-infrastructure of factory’s manufacturing execution system. Microsoft threat modeling methodology utilizes STRIDE –mnemonic and data flow diagrams to find threats. Threat modeling in this thesis returned results that were important for the organization. Acme Corporation now has more comprehensive understanding concerning IT-infrastructure of the manufacturing execution system. On top of vulnerability related results threat modeling provided coherent views of the target system. Subject matter experts from different areas can now agree upon functions and dependencies of the target system. Threat modeling was recognized as a useful activity for improving security.

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Despite the increasing public profile of lesbian childbearing, public health resources for expectant women often bear heterosexist assumptions and create barriers to accessing information relevant to lesbian mothering experiences. This descriptive, exploratory study examined one lesbian couple's perceived educational needs for effective support, barriers to access, strategies for locating care, and the impact of childbearing on their lives, as well as their reflections on inviting ways to offer supportive practices in a public health context. A case study approach used feminist ethnographic methodology and purposeful convenience sampling. A prenatal and a postnatal open-ended interview were completed with 1 white, middle-class, able, lesbian childbearing couple, each ofwhom has birthed as coparent and biological mother in this couple relationship. Despite this couple's immense situated privilege, they struggled to locate the support they sought for childbearing in a way that offered optimal emotional and physical care from the preconceptual to postpartum stages and which maintained confidentiality or anonymity as desired. They created meaningful care through personal networks. The findings were framed using invitational and feminist theories: how people, places, programs, processes, policies, and politics contributed to educational support. A three part conceptual framework emerged which identified components of access to support: perceived safety of resources, disclosure status, situated privilege, and public or private availability of information. The consequences of lack of public access to comprehensive childbearing care for lesbian women and their communities are described. Educational possibilities addressed systemic heterosexism through the development of sensitive educators, meaningful curriculum, program planning, explicit policies, community partnerships, and political leadership with respect to both institutional and research venues.

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The purpose of this study was to examine processes and interactions that characterized positive developmental experiences in sport. A highly competitive and reputable U-17 girls' soccer team was chosen for the study through purposeful sampling, providing an information rich case from which data could be derived (Patton, 2002). Seventeen players and three coaches participated in this study. Based on an ethnographic methodology data were collected via observations and both informal and formal semi-structured interviews. Tlie data were coded according to the three procedures outlined by Seidel and Kelle (1995): a) noticing relevant phenomena, b) collecting examples of those phenomena, and c) analyzing those phenomena in order to find commonalities, differences, patterns and structures. Significant events and underlying themes were recounted chronologically through a collection of vignettes, aimed to provide a contextual lens for the reader. Results revolved around two prominent themes: Teamwork and leadership. These were closely related concepts that required players to demonstrate a wide range of developmental skills for the team to move collectively towards their end goal. Furthermore, teamwork and leadership experiences took both desirable and undesirable forms. For example, at the beginning of the season competition existed amongst the players at the expense of teamwork and leadership. As the season progressed the pursuit of a shared goal allowed the players to view each other as collaborators and teamwork and leadership skills became increasingly evident. At times, however, success on the field was prioritized above maintaining relationships off the field, requiring the coaches to intervene and re-establish equilibrium.

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The research question in this study was "How do the noninstitutionalized elderly in the Hamilton-Wentworth Region perceive their learning needs and interests related to health?" The theoretical foundations of instruction for adults were reviewed as well as learning needs and interests in adult education, the assessment of learning needs in general, and the assessment of the learning needs of the elderly. The methodology used was a descriptive design. A research-based questionnaire-interview was developed, refined, and pilot tested. From a random sampling procedure, a participant group of 23 was secured. The questionnaireinterview was administered in a home visit situation. Data, which were collected, were coded, analyzed, processed, and printed. The results indicated that each participant had many learning needs and interests of varying intensities. The participants had many preferences in the delivery of health promotion. The learning needs and interests had several significant correlations with other variables. The implications of the result~ were discussed.

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The purpose of this study was to assess the effects of changing a nursing documentation system, developed from King's Conceptual Framework, on the use of the nursing process. The null hypothesis was that there would be no significant increase in the reflection of the use of the nursing process on the nursing care plan or nurses' notes, as a result of using a nursing documentation system developed using King's Conceptual Framework (1981). The design involved the development of a questionnaire that was used to review health records pre and post implementation of a documentation system developed based on King's Conceptual Framework and Theory of Goal Attainment (1981). A Record Completeness Score was obtained from some of the questions. The null hypothesis was rejected. The results of the study have implications for nursing administration and the evaluation of nursing practice. If the use of a documentation system developed from a conceptual framework increases the reflection of the nursing process on the patient's health record, nursing will have the means to measure patient outcomes/goal attainment. All health care organizations and levels of government are focusing on methods to monitor and control the health-care dollar. In order for nursing to clearly determine the costs associated with nursing care, measurement of patient outcomes/goal attainment will need to be possible. In order to measure patient outcomes/goals attainment nurses will need to be able to collect data on their practice. It will be critical that nursing have a documentation system in place which facilitates the reflection of the nursing process within a theoretical framework.

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A new approach to treating large Z systems by quantum Monte Carlo has been developed. It naturally leads to notion of the 'valence energy'. Possibilities of the new approach has been explored by optimizing the wave function for CuH and Cu and computing dissociation energy and dipole moment of CuH using variational Monte Carlo. The dissociation energy obtained is about 40% smaller than the experimental value; the method is comparable with SCF and simple pseudopotential calculations. The dipole moment differs from the best theoretical estimate by about 50% what is again comparable with other methods (Complete Active Space SCF and pseudopotential methods).

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The prediction of proteins' conformation helps to understand their exhibited functions, allows for modeling and allows for the possible synthesis of the studied protein. Our research is focused on a sub-problem of protein folding known as side-chain packing. Its computational complexity has been proven to be NP-Hard. The motivation behind our study is to offer the scientific community a means to obtain faster conformation approximations for small to large proteins over currently available methods. As the size of proteins increases, current techniques become unusable due to the exponential nature of the problem. We investigated the capabilities of a hybrid genetic algorithm / simulated annealing technique to predict the low-energy conformational states of various sized proteins and to generate statistical distributions of the studied proteins' molecular ensemble for pKa predictions. Our algorithm produced errors to experimental results within .acceptable margins and offered considerable speed up depending on the protein and on the rotameric states' resolution used.