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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
411

Evaluating Multi-Level Factors Influencing Adolescent Sugar Sweetened Beverage Consumption

Griecci, Christina F. 30 March 2018 (has links)
Background: Sugar sweetened beverages (SSBs) comprise the largest source of added sugars in US adolescents’ diets. SSB consumption is pervasive in US culture and is a critical risk factor for weight gain and obesity in adolescents. This thesis evaluates multi-level factors that influence adolescent SSB consumption. Methods: The first two aims of this thesis utilized data from the cross sectional, internet based Family Life, Activity, Sun, Health and Eating (FLASHE) study to: 1) examine availability of SSBs in multiple settings (home, school, neighborhood) and adolescent SSB consumption, 2) examine the associations between perceptions of parenting practices and adolescent SSB consumption. The third aim used focus group discussions to understand adolescents’ perceptions about SSBs. Results: We found that SSB availability in the home was an important predictor of adolescent SSB consumption, regardless of SSB availability in other settings. Also, parenting practices that facilitate adolescent SSB consumption are associated with higher adolescent SSB consumption, but discussing/negotiating SSB behaviors is not associated with adolescent SSB consumption. Adolescents’ described their attitudes, reinforcements, knowledge, and sources of influence around SSBs which are multifactorial and complex. Conclusions: This thesis identified potential targets for addressing adolescent SSB consumption through availability of SSBs at home, parenting practices, and adolescent perceptions around SSBs. These are important modifiable factors in the adolescents’ sociocultural environment that should be targeted in future dietary interventions to influence adolescent SBB consumption.
412

The Effects of Green Smoothie Consumption on Blood Pressure and Health-Related Quality of Life: A Randomized Controlled Trial

Maeda, Emiko 14 June 2013 (has links)
Chronic diseases are among the leading causes of death globally, and as much as 80% of these deaths are reported to be preventable with proper diet and lifestyle. Although extensive research has demonstrated that the increased consumption of fruits and vegetables offers protective health effects from many chronic illnesses, populations in both developed and developing nations consistently fall short of the recommended intake of 5 or more servings a day. This study investigated the effects of daily consumption of Green Smoothies for 4 consecutive weeks on blood pressure and health-related quality of life. Green Smoothies are a blended drink consisting of fruit, leafy greens and water. The study was a randomized controlled trial with a final sample of 29 volunteer participants. Data were collected at baseline and post-intervention and included anthropometric and physiologic measures, as well as a nutrition survey. The treatment group demonstrated trends toward improvements in waist circumference (p = 0.026), waist-to-hip ratio (p = 0.05), and symptoms of burden linked to diet (p = 0.04), small intestine (p = 0.04), large intestine (p = 0.05), and mineral needs (p = 0.04). Despite the lack of statistically significant reductions in blood pressure, the trend toward improvements in waist circumference and waist-to-hip ratio are considered to be useful and informative of health risk. Thus, the results of this study provide preliminary support for the consumption of Green Smoothies as a possible primary prevention effort for chronic conditions. It may also help to reduce health risks or even reverse the effects of chronic conditions.
413

The Role of Recovery from Work in Work Stress-Related Drinking

Shepherd, Brittnie Renae 10 November 2016 (has links)
Alcohol consumption has been linked to numerous adverse health and well-being outcomes; therefore determining what motivates individuals to drink is of utmost importance. One reason individuals may drink is to cope with work demands and their associated strain. This may be especially relevant for correctional officers (COs) as this occupation has been associated with high levels of job stressors and strain and heavy drinking. Drawing primarily on the job demands-resources and ego depletion models, this study examined how emotional job demands contribute to CO exhaustion and alcohol use. Additionally, interactions between common recovery from work experiences and exhaustion were tested to determine if recovery experiences could serve as a protective influence against work stress-related drinking. Participants were 1,370 correctional officers from 14 correctional facilities within the state of Oregon. Results indicate that exhaustion was positively related to both drinking quantity and drinking frequency and that emotional job demands had significant indirect effects on both types of drinking behaviors through employee exhaustion. The recovery experiences relaxation and detachment significantly moderated the relationship between exhaustion and drinking quantity, but not drinking frequency. Mastery experiences did not influence the strength of the positive relationship between exhaustion and either drinking outcome. These findings suggest that engaging in certain recovery experiences may lead to drinking fewer drinks on days when drinking, however the frequency of those days remains unaffected.
414

Punktskatt på sötade drycker i Sverige : En kostnads-nyttoanalys / Tax on sugar-sweetened beverages in Sweden : A cost-benefit analysis

Huss, Ellen, Solsten, Simon January 2023 (has links)
Unhealthy eating habits are one of the main causes of deteriorating health and premature death among Sweden’s population. Foods containing added sugars are common today and they rarely contain the nutrients that are essential for our bodies to stay healthy. Overconsuming sugar can lead to several diseases, including obesity and caries. Obesity in turn increases the risk of suffering from cardiovascular diseases, cancer, stroke, and diabetes type 2. The health effects of sugar are costly to society and a sugar tax on sugar-sweetened beverages is a possible financial instrument to improve public health and at the same time reduce healthcare costs. The cost savings and tax revenue can then be used to finance further implementations of strategies to improve the public health of the citizens of Sweden. The purpose of this essay is to investigate whether it is socio-economically viable to introduce an excise tax on sugar-sweetened beverages in Sweden. The drinks that would be affected by the tax are sodas, juices, energy drinks, sport drinks and ciders. A cost-benefit analysis is the economic method that will be used in this essay to investigate the issue. The possible costs and benefits from the implementation of a tax are identified and valued in monetary terms. In addition to this, a sensitivity analysis is carried out to test how sensitive the project is to differences in estimated costs and benefits. The calculations of costs and benefits are based on secondary data and statistics from previous studies as well as reports and statistics from Swedish authorities. The results of this essay show that the benefits of a tax on sugar-sweetened beverages had exceeded the costs, which is also showed by the cost-benefit ratio which is 1,47 and thus exceeds 1. The sensitivity analysis shows that the results are stable and credible since alternative values of costs and benefits also would lead to cost-benefit ratios exceeding 1. Based on the results, a recommendation is made to introduce an excise tax on sugar-sweetened beverages in Sweden, since the introduction is estimated to be socio-economically viable. / I denna uppsats utförs en kostnads-nyttoanalys för att undersöka om det är samhällsekonomiskt lönsamt att införa en punktskatt på sötad dryck i Sverige. De drycker som skulle påverkas av skatten är läsk, juice, saft, energidryck, sportdryck, cider samt måltidsdryck som är sötade med socker eller naturligt innehåller en hög sockerhalt. Socker har endast negativ påverkan på vår hälsa och överkonsumtion av socker är en orsak till ett flertal sjukdomar som är vanligt förekommande idag, bland annat övervikt och karies. Övervikt ökar i sin tur risken för att drabbas av fetma, hjärt- och kärlsjukdomar, cancer, stroke och diabetes typ 2. Hälsoeffekterna av socker är kostsamma för samhället och en sockerskatt på dryck är ett möjligt styrmedel för att förbättra folkhälsan och samtidigt minska dessa kostnader. Kostnadsbesparingarna kan därefter distribueras till viktiga ändamål, exempelvis för att finansiera ytterligare strategier för en bättre hälsa hos befolkningen. Resultaten i uppsatsen visar att fördelarna av en skatt på sötade drycker hade överstigit kostnaderna, vilket går att se då nyttokostnadskvoten som beräknas uppgår till 1,47 och alltså överstiger 1. Utöver kostnads-nyttoanalysen utförs även en känslighetsanalys för att testa hur känsligt resultatet är för förändringar av värdet för olika parametrar som kommer påverkas av införandet av skatten. Känslighetsanalysen visar att resultatet är stabilt och trovärdigt då även alternativa värden leder till en nyttokostnadskvot som överstiger 1. Resultatet används som grund för en rekommendation om att införa en punktskatt på sötade drycker i Sverige, då införandet är samhällsekonomiskt lönsamt.
415

Identification of Purpurogallin in Brewed Beverages and Effect of Roasting on Antioxidant Activity and Phenolic Compounds in Coffees

Liao, Yu-Chen 11 December 2015 (has links)
Coffee contains many antioxidants including purpurogallin, which is a hydrophobic phenolic antioxidant that is difficult to measure with reported methods. A method combining solid-phase extraction and liquid chromatography–mass spectrometry was developed to detect and quantify purpurogallin in brewed beverages, including coffee. For beverage preparation, water extraction was adopted for improved correlation with moka pot brewing. Purpurogallin was detected in all commercial coffee samples, and its content in ground coffees ranged from 455-630 ng/g dry weight. Purpurogallin was only detected in two English breakfast tea samples (335-360 ng/g dry weight) and was not detected in any cocoa sample. Antioxidant activity, total phenolic content, and phenolic profile of coffees with different degrees of roasting were determined and analyzed. The developed methodology was then further improved, and coffees with different roasting degrees were analyzed for their antioxidant activity, total phenolic content, and phenolic profile. The antioxidant activity ranged from 63.9-92.0 mg Trolox equivalents per gram of coffee (dry weight), and the total phenolic content ranged from 36.0-57.7 mg gallic acid equivalents per gram of coffee (dry weight). However, the total phenolic content was not correlated with the roasting degree (p > 0.05). When the roasting degree increases, chlorogenic acid decreases drastically, but shikimic acid, caffeic acid, gallic acid, pyrogallol, and purpurogallin increase correspondingly. The results suggest that purpurogallin is a common antioxidant in roasted coffees, and an increase in roasting degree will not only lead to dramatic breakdown of chlorogenic acid, but also promote significant formation of other phenolic compounds that can provide antioxidant activity.
416

Sockersötade drycker och bukspottkörtelcancer : Sambandet mellan intag av sockersötade drycker och risk för bukspottkörtelcancer / Sugar-sweetened beverages and pancreas cancer : Consumption of sugar-sweetened beverages and risk of pancreas cancer

Lundqvist, Jenny January 2023 (has links)
Bakgrund: Sockersötade drycker är drycker till vilka sockerarter tillsatts. Dessa drycker konsumeras globalt och många gånger överskrids rekommendationerna om intag av tillsatt socker, vilket kan leda till negativa hälsoeffekter. Sockersötade drycker kan öka risken att drabbas av övervikt, fetma och typ 2-diabetes som i sin tur är riskfaktorer för att utveckla bukspottkörtelcancer. Det finns därför ett ökat intresse att undersöka den potentiellt ökade cancerrisken vid konsumtion av sockersötade drycker. Syfte: Syftet var att undersöka om intag av sockersötade drycker kan öka risken att drabbas av bukspottkörtelcancer. Metod: Arbetet är en litteraturstudie där vetenskapliga artiklar sökts med databasen PubMed. Sökorden var ”sugar-sweetened beverages” och ”pancreas cancer”. Av de artiklar som erhölls inkluderades observationsstudier och kliniska studier. Utifrån ytterligare inklusions- och exklusionskriterier valdes sju studier ut och granskades. Resultat: Resultat från tre av sju studier visar att det inte förekommer något samband mellan konsumtion av sockersötad dryck och risk för bukspottkörtelcancer medan resultat från tre studier påvisar samband. Resultat från en studie visar att det finns samband hos kvinnor men inte hos män. Slutsats: Hälften av studierna visar ett samband mellan konsumtion av sockersötad dryck och en ökad risk att drabbas av bukspottkörtelcancer. För att minska risken kan det således vara fördelaktigt att följa de rekommendationer som finns kring tillsatt socker. / Background: Sugar-sweetened beverages are beverages to which sugars are added. These beverages are consumed globally and many times the recommendations on added sugar are exceeded, which can lead to negative health effects. Sugar-sweetened beverages may increase the risk of overweight, obesity and type 2 diabetes which are risk factors for developing pancreatic cancer. Thus, there is an increased interest to study the potentially increased cancer risk associated with the consumption of sugar-sweetened beverages. Aim: The aim was to examine whether consumption of sugar-sweetened beverages can increase the risk of pancreatic cancer. Method: This work is a literature study using scientific articles searched with the database PubMed. The search terms were “sugar-sweetened beverages” and “pancreas cancer.” Of the articles obtained, observational studies and clinical studies were included. Based on inclusion and exclusion criteria, seven studies were selected and reviewed. Results: Results from three of seven studies show that there is no relationship between consumption of sugar-sweetened beverages and risk of pancreatic cancer, while results from three other studies show that there is a relationship. Results from one study show that there is a relationship in women but not in men. Conclusion: Half of the studies shows that there is a relationship between consumption of sugar-sweetened beverages and increase the risk of pancreatic cancer. To reduce the risk, it can be beneficial to follow the recommendations that exist regarding added sugar.
417

The Creation and Validation of the Activation-Valence Affective Traits Survey (AVATS)

Coskunpinar, Ayca 03 July 2012 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Aim: The goals of the current studies were to (a) create a measure of affective traits that can assess both the discrete and the underlying dimensions of affective traits and (b) examine the reliability and validity of the scale in two independent samples. Participants: Participants were undergraduate students at a large, public US mid-western university (Study 1 N = 616; Study 2 N = 510). The mean age for Study 1 was 21.10 (SD = 5.05) and 21.02 for Study 2 (SD = 4.96). Design: Exploratory and confirmatory factor analyses were conducted to examine internal factor structure of the scale. A series of correlational, reliability, and hierarchical regression analyses were conducted to examine convergent, divergent, and criterion-related validity of the new scale. Findings: Activation-Valence Affective Traits Survey (AVATS) had good reliability and adequate construct, convergent, and discriminant validity as a measure of affective traits. Conclusions: This study introduces a new scale for measuring affective traits that offers more information on both the categorical and dimensional conceptualizations of affective traits, which also has predictive utility in relation to problem-related alcohol consumption.
418

Evaluation Of The Expectancy Challenge Alcohol Literacy Curriculum (ecalc) For Reducing Alcohol Use Among High School Students

Sivasithamparam, Janani 01 January 2011 (has links)
Alcohol use is the single most alarming behavior among youth in the United States. Adolescents especially are at risk for increases in heavy episodic drinking and drunkenness leading to alcohol-related problems such as academic failure, interpersonal violence, risky sexual behavior and death. In an effort to address this endemic issue, a number of alcohol use prevention programs have been developed and are currently implemented in the high school setting. Many of these programs, however, lack an empirical basis and have been unable to demonstrate significant reductions in alcohol use over time. The need for the development and dissemination of effective strategies to address adolescent drinking is evident. Recommendations for newly developing approaches encourage an emphasis on empiricallybased content and easily implemented protocols. Expectancy challenge-based interventions have been identified by the National Institute on Alcohol Abuse and Alcoholism as having strong evidence supporting their effectiveness in reducing alcohol use among college students. Recent efforts to translate such programs into forms effective with high school adolescents have been met with mixed results. The focus of the present study was to modify, implement and evaluate the Expectancy Challenge Alcohol Literacy Curriculum (ECALC), a program currently validated for use with college populations, for high school adolescents. The single session, high school version of the ECALC was infused into the existing Health Education high school curriculum and implemented with those in the 9th through 12th grades. Measures of alcohol expectancies and alcohol use were completed anonymously by each participant before delivery of the program and for 30 days thereafter. Impact of the ECALC was compared to classes randomly assigned to an attention-matched control condition. Findings revealed significant changes in alcohol expectancies and alcohol use reported by participants in the 11th and 12th grades following iv delivery of the ECALC. Changes were found across factor analytic and multidimensional scaling (MDS) statistical methods applied to the expectancy measure, as well as across measures of estimated intoxication and drinking quantity/frequency. Findings were consistent among both male and female participants. Reductions in alcohol use were not found among 9th and 10th grade participants, and expectancy changes were inconsistent. The assessment periods for baseline and follow-up were thirty days, which may reflect a limitation in that a longer follow-up may be more likely to capture significant behavioral changes over time. This study was the first to apply both factor analytic and MDS methods to analysis of the Comprehensive Effects of Alcohol questionnaire, with clear implications for expectancy measurement techniques likely to be most appropriate for capturing changes in expectancy activation patterns over time. Overall, this study represents an important advance in the development of an empirically-based and validated alcohol use prevention program effective for use with adolescents. In addition, the ECALC serves as a prevention program that is easily implemented in the high school setting, requiring only 50 minutes of class time, a classroom, and a motivated educator.
419

Development of polymeric and silica filtering materials functionalized with antimicrobial compounds for the elimination of microorganisms in liquid food

Peña Gomez, Natalie 17 February 2020 (has links)
Tesis por compendio / [ES] En la presente tesis doctoral se ha evaluado el uso de nuevos soportes celulósicos y silíceos como sistemas de filtración para la estabilización y conservación de alimentos líquidos con el fin de afrontar dos grandes retos de la industria de bebidas. Por un lado, evitar o minimizar los cambios en las propiedades nutricionales, estructurales y organolépticas de los alimentos, ocasionados por la pasteurización térmica tradicional, y ofrecer una alternativa al problema de la baja viabilidad debida a los altos costos de inversión/producción al aplicar nuevas tecnologías no térmicas. Por ello, esta tesis doctoral se centra en el desarrollo y evaluación de una nueva tecnología no térmica de conservación de alimentos líquidos basada en la filtración. Se han desarrollado sistemas de filtración a partir de soportes celulósicos y silíceos, sin funcionalizar o funcionalizados con compuestos antimicrobianos. En el primer capítulo se evaluó el uso de materiales de celulosa como soportes filtrantes para el tratamiento de alimentos líquidos. Como primera aproximación se desarrolló un material poroso nano-micro tubular a partir de la extracción y deslignificación del material celulósico presente en el corazón o raquis de la mazorca de maíz. El uso de este soporte resultó ser efectivo como material filtrante para el tratamiento de agua y zumo de naranja, en un sistema de flujo continuo, eliminando la carga microbiana. La aplicación de este soporte como sistema de filtración presenta diversas ventajas como su capacidad de retención microbiana, la reutilización de sub-productos del maíz y, por tanto, su respeto al medioambiente. Sin embargo, sería necesario optimizar el proceso de filtrado para evitar la frecuente obturación de sus poros que requirió varios ciclos de lavado durante el proceso, así como establecer un método de regeneración del material para incrementar su vida útil. Además, este sistema afectó al color del zumo filtrado, que no se mantuvo constante durante el proceso, lo que supone una importante desventaja que es necesaria abordar. Como segunda aproximación, se evaluó el potencial de la inmovilización de una molécula bioactiva sobre membranas de celulosa, para mejorar la capacidad de retención microbiana del material celulósico, así como permitir su reutilización. Los filtros de celulosa funcionalizados con poliaminas demostraron ser eficaces en la eliminación de patógenos en agua, debido a las cargas positivas generadas por los grupos amina inmovilizados en la superficie de las membranas, que atraen y retienen las bacterias cargadas negativamente. Dada la fácil preparación y procedimiento de uso de las membranas de celulosa funcionalizadas con poliaminas, éstas podrían ser consideradas una buena opción para el desarrollo de sistemas de tratamiento de aguas in situ, rápidos, de fácil manejo y de bajo coste. El segundo capítulo describe el desarrollo y aplicación de partículas de sílice funcionalizadas con compuestos de aceites esenciales, con el fin de diseñar coadyuvantes de filtración con actividad antimicrobiana. La filtración de diversas matrices alimentarias (agua, cerveza y zumo de manzana) a través de los soportes funcionalizados con los antimicrobianos naturales demostró ser eficaz en la reducción del recuento de la cepa patógena Escherichia coli, así como frente a la microflora endógena de la cerveza y el zumo (bacterias acidolácticas, aerobios mesófilos, psicrófilos, mohos y levaduras). La eficacia en el control microbiano se debe a la combinación de la adsorción física y la inactivación por contacto con los compuestos de aceites esenciales inmovilizados. Además, la evaluación de las propiedades físico-químicas y sensoriales de los alimentos líquidos demostró un efecto poco significativo, éste depende del tamaño de las partículas de sílice usadas y de la molécula bioactiva inmovilizada. Por lo tanto, el sistema de conservaci� / [CA] En la present tesi doctoral s'ha avaluat l'ús de nous suports cel·lulòsics i silicis com a sistemes de filtració per a l'estabilització i conservació d'aliments líquids, amb la finalitat d'afrontar dos grans reptes de la indústria de begudes. D'una banda, evitar o minimitzar els canvis en les propietats nutricionals, estructurals i organolèptiques dels aliments, ocasionats per la pasteurització tèrmica tradicional, i oferir una alternativa al problema de la baixa viabilitat deguda als alts costos d'inversió/producció en aplicar noves tecnologies no tèrmiques. Per això, aquesta tesi doctoral es centra en el desenvolupament i avaluació d'una nova tecnologia no tèrmica de conservació d'aliments líquids basada en la filtració. S'han desenvolupat sistemes de filtració a partir de suports cel·lulòsics i silicis, sense funcionalitzar o funcionalitzats amb compostos antimicrobians. En el primer capítol es va avaluar l'ús de materials de cel·lulosa com a suports filtrants per al tractament d'aliments líquids. Com a primera aproximació es va desenvolupar un material porós nano-micro tubular a partir de l'extracció i deslignificació del material cel·lulòsic present en el cor o raquis de la panolla de dacsa. L'ús d'aquest suport va resultar ser efectiu com a material filtrant per al tractament d'aigua i suc de taronja, en un sistema de flux continu, eliminant la càrrega microbiana. L'aplicació d'aquest suport com a sistema de filtració presenta diversos avantatges com la seua capacitat de retenció microbiana, la reutilització de subproductes de la dacsa i, per tant, el seu respecte al medi ambient. No obstant això, seria necessari optimitzar el procés de filtrat per a evitar la freqüent obturació dels seus porus que va requerir diversos cicles de rentada durant el procés, així com establir un mètode de regeneració del material per a incrementar la seua vida útil. A més, aquest sistema va afectar el color del suc filtrat, que no es va mantenir constant durant el procés, la qual cosa suposa un important desavantatge que és necessari abordar. Com a segona aproximació, es va avaluar el potencial de la immobilització d'una molècula bioactiva sobre membranes de cel·lulosa, per a millorar la capacitat de retenció microbiana del material cel·lulòsic, així com permetre la seua reutilització. Els filtres de cel·lulosa funcionalitzats amb poliamines van demostrar ser eficaces en l'eliminació de patògens en aigua, a causa de les càrregues positives generades pels grups amina immobilitzats en la superfície de les membranes, que atrauen i retenen els bacteris carregats negativament. Donada la fàcil preparació i procediment d'ús de les membranes de cel·lulosa funcionalitzades amb poliamines, aquestes podrien ser considerades una bona opció per al desenvolupament de sistemes de tractament d'aigües in situ, ràpids, de fàcil maneig i de baix cost. El segon capítol descriu el desenvolupament i aplicació de partícules de sílice funcionalitzades amb compostos d'olis essencials, amb la finalitat de dissenyar coadjuvants de filtració amb activitat antimicrobiana. La filtració de diverses matrius alimentàries (aigua, cervesa i suc de poma) a través dels suports funcionalitzats amb els antimicrobians naturals va demostrar ser eficaç en la reducció del recompte del cep patogen Escherichia coli, així com enfront de la microflora endògena de la cervesa i el suc (bacteris àcid làctics, aerobis mesòfils, psicròfils, floridures i llevats). L'eficàcia en el control microbià es deu a la combinació de l'adsorció física i la inactivació per contacte amb els compostos d'olis essencials immobilitzats. A més, l'avaluació de les propietats fisicoquímiques i sensorials dels aliments líquids estudiats va demostrar un efecte poc significatiu, aquest depèn de la grandària de les partícules de sílice usades i de la molècula bioactiva immobilitzada. Per tant, el sistema de conserv / [EN] In the present doctoral thesis the use of new cellulosic and silica supports as filtering systems for the stabilization and preservation of liquid foods has been evaluated to overcome two major challenges of the beverage industry. On the one hand, avoid or minimize the changes in the nutritional, structural and organoleptic properties of food caused by traditional thermal pasteurization, and offer an alternative to the problem of low viability due to high investment/production costs when applying new non-thermal technologies. Therefore, this doctoral thesis focuses on the development and evaluation of a new non-thermal technology for the preservation of liquid foods based on filtration. The filtering systems have been developed from cellulosic and silica supports, non-modified or functionalized with antimicrobial compounds. In the first chapter, the use of cellulose materials as filtering supports for the treatment of liquid foods was evaluated. As first approximation, a porous nano-micro tubular material was developed from the extraction and delignification of the cellulosic material present in the corn stalk. The use of this support was effective as filtering material for the treatment of water and orange juice, in a continuous flow system, eliminating the microbial load. The application of this support as filtering system has several advantages, such as its microbial retention capacity, the reuse of corn by-products and, therefore, its respect for the environment. However, it would be necessary to optimize the filtering process to avoid the frequent clogging of its pores that required several washing cycles during the process, as well as to establish a method of material regeneration to increase its life. In addition, this system affected the color of the filtered juice, which did not remain constant during the process, representing an important disadvantage that must be addressed. As a second approach, the potential of the immobilization of a bioactive molecule on cellulose membranes was evaluated to improve the microbial retention capacity of the cellulosic material, as well as to allow its reuse. The cellulose filters functionalized with polyamines proved to be effective in eliminating pathogens in water, due to the positive charges generated by the amine groups immobilized on the surface of the membranes, which attract and retain the negatively charged bacteria. Given the easy preparation and usage of the polyamines-functionalized cellulose membranes, these could be considered a good option for the development of fast, easy to use and low cost in situ water treatment systems. The second chapter describes the development and application of silica particles functionalized with essential oil components to design filtering aids with antimicrobial activity. The filtration of various food matrices (water, beer and apple juice) through the supports functionalized with natural antimicrobials proved to be effective in reducing the load of the pathogenic strain Escherichia coli, as well as reducing the endogenous microflora of beer and the juice (lactic acid bacteria, mesophilic, psychrophilic, mold and yeast). The removal capability is due to the combination of physical adsorption and contact inactivation with the essential oil compounds immobilized. In addition, the evaluation of the physicochemical and sensory properties of the liquid foods studied showed a not significant effect, it depends on the size of the silica particles used and the immobilized bioactive molecule. Therefore, the proposed preservation system has a high potential for cold beverage pasteurization processes. / N. Peña-Gomez would like to thank for financial support in the frame of her PhD project to Operational Programme of the European Social Fund (ESF) 2014-2020, the Agencia Estatal de Investigación, Generalitat Valenciana and FEDER-EU (Projects RTI2018-101599-B-C21 and AGL2015-70235-C2-1-R). The authors also thank the Electronic Microscopy & Microanalysis Laboratory at Patras University for support. / Peña Gomez, N. (2020). Development of polymeric and silica filtering materials functionalized with antimicrobial compounds for the elimination of microorganisms in liquid food [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/137041 / Compendio
420

Perceptions of postdrinking anxiety: effect of sex, beverage, and sex of companion

Wertz, Jennifer S. 30 December 2008 (has links)
The purpose of the current studies was to look at the importance of contextual and individual difference factors, as well as sex differences, on the expected effects of alcohol. The vulnerability and gender role violation hypotheses were examined as explanations for previous findings of sex differences in anxiety responses to alcohol consumption within heterosexual social situations. In the first study, the contextual variables of sex of the target being rated and sex of target’s companion as well as the factors of sex of subject and beverage consumed were examined to clarify the role of anxiety related to the presence of opposite sex companions and anxiety. The factors of sex of companion, sex of target, and beverage were manipulated within a vignette format. Subjects were asked to read the vignette and to answer questions about the main character in the vignette. There were significant beverage by sex of subject interactions indicating that male subjects expected alcohol to reduce impairment and increase social appeal relative to female subjects who tended to expect that consuming alcohol would decrease social appeal and increase impairment. In addition, male subjects expected alcohol to decrease anxiety and increase social skill while female subjects did not expect such an increase and, instead, expected a decrease in social skill in male targets drinking alcohol and no effect on anxiety. These findings did not support either the hypothesis of vulnerability or of gender role violation as explanations of sex differences in alcohol expectancies. Based on the findings of the first study, the goals of the second study were to tease apart possible relationships that individual differences in gender role, sexual description of target and additional motivation to impress the companion could have with feelings of anxiety and other alcohol expectancies in a situation in which both alcohol and being with an opposite sex companion are involved. This was done within a vignette format. Described target sexuality, motivation to impress, and discomfort with behaviors outside the traditional feminine gender role were not found to moderate alcohol expectancies. Interpretation of the results in relation to the vulnerability and gender role violation hypotheses and directions for future research are discussed. / Master of Science

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