29,969 research outputs found

    Desarrollo de papeles biocativos por injerto de mol茅culas espec铆ficas en celulosa

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    Tesis (DCI)--FCEFN-UNC, 2019En la presente tesis se presenta el desarrollo de papeles bioactivos con potencial aplicaci贸n en el envasado activo de alimentos. Para tal fin, se propuso el injerto de eugenol, un compuesto de origen natural con propiedades antimicrobiana, antioxidante y repelente de insectos, en celulosa, utilizando 谩cido policarbox铆lico como agente ligante. Con el objetivo de evaluar la escalabilidad del proceso propuesto, se estudiaron distintas tecnolog铆as de curado, tales como calentamiento por convecci贸n, infrarrojo, microondas y conducci贸n. En todos los casos, se analizaron la influencia de las variables operativas sobre el avance de la reacci贸n y propiedades finales del papel preparado, utilizando un dise帽o de experimentos Doehlert para elegir las experiencias a realizar, y analizando los resultados mediante metodolog铆a de superficie de respuesta y an谩lisis estad铆stico ANOVA. Se pudo comprobar que la reacci贸n de injerto de eugenol en papel comercial se produjo con 茅xito en todas las tecnolog铆as estudiadas. Asimismo, se encontraron las condiciones 贸ptimas de reacci贸n para cada una de las tecnolog铆as, para lo cual se busc贸 un compromiso entre el avance de la reacci贸n y las propiedades finales del material (mec谩nicas y color). A partir de estas condiciones, se prepararon papeles y se realiz贸 una caracterizaci贸n m谩s espec铆fica para su aplicaci贸n como envase de alimentos comparando los papeles modificados con el papel virgen. Se analizaron las propiedades mec谩nicas por ensayo de tracci贸n, rasgado y punzonado y se midi贸 la absorci贸n de agua y la capacidad de degradaci贸n. Por otro lado, las propiedades bioactivas analizadas fueron la actividad antioxidante, antimicrobiana, repelente e insecticida de gorgojos (T. castaneum y R. dominica). Una vez probado que el papel modificado presenta buenas caracter铆sticas f铆sicas y bioactivas para su posible aplicaci贸n en el envasado de alimentos, se realizaron prototipos de envasado para harina, como alimento representativo de alimentos derivados de cereales, susceptibles al ataque de plagas. En este estudio se analiz贸 la migraci贸n de reactivos, propiedades organol茅pticas y conservaci贸n del alimento, arrojando resultados promisorios para la industria de envases de alimentos. Finalmente, se realiz贸 una comparaci贸n de las tecnolog铆as de curado ensayadas, analizando diferentes aspectos como avance de reacci贸n, propiedades finales, apariencia, tiempo de reacci贸n, consumo de energ铆a, entre otros, como as铆 tambi茅n disponibilidad y uso de estas tecnolog铆as a escala industrial, seleccionando la tecnolog铆a de conducci贸n como la m谩s adecuada para una propuesta de escalado industrial.Fil: Muratore, Florencia. Universidad Nacional de C贸rdoba. Facultad de Ciencias Exactas, F铆sicas y Naturales; Argentina.Fil: Muratore, Florencia. Consejo Nacional de Investigaciones Cient铆ficas y T茅cnicas. Instituto de Investigaci贸n y Desarrollo en Ingenier铆a de Procesos y Qu铆mica Aplicada; Argentina

    Identifying and responding to people with mild learning disabilities in the probation service

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    It has long been recognised that, like many other individuals, people with learningdisabilities find their way into the criminal justice system. This fact is not disputed. Whathas been disputed, however, is the extent to which those with learning disabilities arerepresented within the various agencies of the criminal justice system and the ways inwhich the criminal justice system (and society) should address this. Recently, social andlegislative confusion over the best way to deal with offenders with learning disabilities andmental health problems has meant that the waters have become even more muddied.Despite current government uncertainty concerning the best way to support offenders withlearning disabilities, the probation service is likely to continue to play a key role in thesupervision of such offenders. The three studies contained herein aim to clarify the extentto which those with learning disabilities are represented in the probation service, toexamine the effectiveness of probation for them and to explore some of the ways in whichprobation could be adapted to fit their needs.Study 1 and study 2 showed that around 10% of offenders on probation in Kent appearedto have an IQ below 75, putting them in the bottom 5% of the general population. Study 3was designed to assess some of the support needs of those with learning disabilities in theprobation service, finding that many of the materials used by the probation service arelikely to be too complex for those with learning disabilities to use effectively. To addressthis, a model for service provision is tentatively suggested. This is based on the findings ofthe three studies and a pragmatic assessment of what the probation service is likely to becapable of achieving in the near future

    Consent and the Construction of the Volunteer: Institutional Settings of Experimental Research on Human Beings in Britain during the Cold War

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    This study challenges the primacy of consent in the history of human experimentation and argues that privileging the cultural frameworks adds nuance to our understanding of the construction of the volunteer in the period 1945 to 1970. Historians and bio-ethicists have argued that medical ethics codes have marked out the parameters of using people as subjects in medical scientific research and that the consent of the subjects was fundamental to their status as volunteers. However, the temporality of the creation of medical ethics codes means that they need to be understood within their historical context. That medical ethics codes arose from a specific historical context rather than a concerted and conscious determination to safeguard the well-being of subjects needs to be acknowledged. The British context of human experimentation is under-researched and there has been even less focus on the cultural frameworks within which experiments took place. This study demonstrates, through a close analysis of the Medical Research Council's Common Cold Research Unit (CCRU) and the government's military research facility, the Chemical Defence Experimental Establishment, Porton Down (Porton), that the `volunteer' in human experiments was a subjective entity whose identity was specific to the institution which recruited and made use of the subject. By examining representations of volunteers in the British press, the rhetoric of the government's collectivist agenda becomes evident and this fed into the institutional construction of the volunteer at the CCRU. In contrast, discussions between Porton scientists, staff members, and government officials demonstrate that the use of military personnel in secret chemical warfare experiments was far more complex. Conflicting interests of the military, the government and the scientific imperative affected how the military volunteer was perceived

    EVALUACI脫N ANALG脡SICA PERIOPERATORIA DEL ACETAMINOF脡N EN PERRAS SOMETIDAS A OVARIOHISTERECTOM脥A ELECTIVA

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    Tesis de doctorado que eval煤a el efecto analg茅sico del acetaminof茅n en perras ovarihisterectomizadas.La administraci贸n de analg茅sicos antiinflamatorios no esteroidales (AINES) para el control del dolor post-quir煤rgico en perros es una pr谩ctica com煤n, debido a sus efectos analg茅sicos, antiinflamatorios y antipir茅ticos. En el presente trabajo se realizaron dos estudios. En el experimento 1, el objetivo fue evaluar la analgesia post-operatoria del acetaminof茅n (paracetamol) a trav茅s de la utilizaci贸n de las escalas de reconocimiento cl铆nico del dolor DIVAS (Escala Din谩mica e Interactiva Anal贸gica Visual) y UMPS (Escala de la Universidad de Melbourne), en perras sometidas a ovariohisterectom铆a electiva. Adem谩s de valorar la seguridad y eficacia cl铆nica del uso del acetaminof茅n en perros mediante pruebas de funcionamiento hep谩tico y renal en el post-operatorio inmediato. Para ello, se utilizaron 30 perras de diferentes razas que fueron asignadas aleatoriamente a uno de los tres grupos de tratamiento: acetaminof茅n [GACET; n=10, 15 mg kg-1 intravenoso (IV)], carprofeno (GCARP; n=10, 4 mg kg-1 IV) y meloxicam (GMELOX; n=10, 0.2 mg kg-1 IV). Todos los tratamientos se administraron 30 minutos antes de la cirug铆a y posterior a esta durante 48 horas. En este per铆odo el acetaminof茅n se administr贸 por v铆a oral cada 8 horas (15 mg kg-1); el carprofeno (4 mg kg-1) y el meloxicam (0.1 mg kg-1) se administraron por v铆a IV cada 24 horas. Durante el postoperatorio, los sistemas de puntuaci贸n del dolor DIVAS y UMPS fueron medidos a las 1, 2, 4, 6, 8, 12, 16, 20, 24, 36 y 48 horas post-cirug铆a. Para evaluar la seguridad cl铆nica de los tratamientos, se recolectaron muestras de sangre de la vena yugular para realizar la medici贸n de enzimas ALT, AST, ALP, y los metabolitos bilirrubina directa, bilirrubina indirecta, bilirrubina total, creatinina, urea, alb煤mina y glucosa. Esto fue realizado en T0 (pre-anestesia; TBASAL), 48 y 96 horas despu茅s de la cirug铆a (T48, T96). Los resultados indican que en la evaluaci贸n cl铆nica del dolor de todos los grupos de estudio, hubo una reducci贸n gradual en la percepci贸n del mismo durante el postoperatorio en ambos sistemas de puntuaci贸n; no obstante, tambi茅n fue observado que ninguna escala difiri贸 significativamente entre los tres grupos de tratamiento (P>0.05) en cada momento de evaluaci贸n durante las 48 horas post-cirug铆a. En cuanto a los par谩metros bioqu铆mico s茅ricos, s贸lo la ALT aument贸 significativamente en T96 en el GACET y GCARP con respecto a los valores basales (P<0.01). El resto de los analitos s茅ricos evaluados se mantuvo en rangos normales. En el experimento 2 bajo el mismo dise帽o experimental de tratamientos administrados, el objetivo fue evaluar el efecto analg茅sico perioperatorio del acetaminof茅n 2 administrado pre y post-quir煤rgicamente en perras sometidas a ovariohisterectom铆a electiva a trav茅s de la medici贸n del 铆ndice de la actividad del tono parasimp谩tico (PTA). Este par谩metro hemodin谩mico fue medido 60 minutos antes de la cirug铆a (TBASAL) y durante el transquir煤rgico en la aplicaci贸n de est铆mulos nociceptivos: colocaci贸n de las pinzas de campo backhouse (TPINZ), incisi贸n de piel y abordaje quir煤rgico primario (TINC), ligadura y extracci贸n de ped铆culo ov谩rico izquierdo (TOVI) y derecho (TOVD), ligadura y transfixi贸n del cuello uterino (TLIGUT), secci贸n quir煤rgica del cuello uterino (TCUT), reconstrucci贸n de peritoneo y planos anat贸micos musculares (TMUSC) y sutura de piel (TSUT). Durante el postoperatorio, el 铆ndice PTA fue valorado a las 1, 2, 4, 6, 8, 12, 16, 20, 24, 36 y 48 horas, en los mismos tiempos en que fueron evaluadas las escalas de reconocimiento de dolor DIVAS y UMPS. Los resultados obtenidos en la medici贸n del 铆ndice PTA basal para GACET fue 65 卤 8, para GCARP 65 卤 7 y para GMELOX 62 卤 5. Durante los diferentes tiempos transquir煤rgicos, los valores promedio de 铆ndice PTA indican que GACET (76 卤 14) y GMELOX (72 卤 18) muestran tendencia a manifestar mayores niveles en comparaci贸n con GCARP (62 卤 13) desde el inicio del procedimiento quir煤rgico sin que esto pudiera comprobarse estad铆sticamente, ya que no hubo diferencias significativas entre grupos de tratamiento ni entre los tiempos quir煤rgicos evaluados (P>0.05). En el postoperatorio, el 铆ndice PTA fue de 65 卤 9 en el GACET, 63 卤 8 en el GCARP y 65 卤 8 en el GMELOX. Los resultados tampoco mostraron diferencias estad铆sticamente significativas con los valores basales o entre los tratamientos (P>0.05). El 铆ndice PTA postoperatorio mostr贸 una sensibilidad del 40%, especificidad del 98.46% y valor predictivo negativo del 99.07% con respecto a la escala validada de UMPS. En conclusi贸n, el acetaminof茅n puede considerarse una herramienta para el tratamiento efectivo del dolor perioperatorio agudo en perros, ya que mostr贸 la misma eficacia cl铆nica que el meloxicam y el carprofeno para la analgesia postquir煤rgica en perras sometidas a ovariohisterectom铆a electiva. Adem谩s, la evidencia del uso de este medicamento no condujo a reacciones adversas o cambios en los par谩metros evaluados, lo que indica su seguridad cl铆nica. Finalmente, destacar que el 铆ndice PTA representa una medici贸n objetiva del comfort y analgesia postoperatoria, por lo que es una herramienta que podr铆a ayudar a predecir las respuestas hemodin谩micas asociadas con el dolor

    Lift EVERY Voice and Sing: An Intersectional Qualitative Study Examining the Experiences of Lesbian, Gay, Bisexual, and Queer Faculty and Administrators at Historically Black Colleges and Universities

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    While there is minimal literature that address the experiences of lesbian, gay, bisexual, and trans* identified students at Historically Black Colleges and Universities (HBCUs), the experiences of Black, queer faculty and administrators at HBCUs has not been studied. This intersectional qualitative research study focused on the experiences of lesbian, gay, bisexual, and queer identified faculty and administrators who work at HBCUs. By investigating the intersections of religion, race, gender, and sexuality within a predominantly Black institution, this study aims to enhance diversity, equity, and inclusion efforts at HBCUs by sharing the experiences of the LGBQ faculty and administrators that previously or currently work at an HBCU as a full-time employee. The research questions that guided this study were 1) How have LGBQ faculty and staff negotiated/navigated their careers at HBCUs? and 2) How do LGBQ faculty and staff at HBCUs influence cultural (relating to LGBQ inclusion) change at the organizational level? The main theoretical framework used was intersectionality and it shaped the chosen methodology and methods. The Politics of Respectability was the second theoretical framework used to describe the intra-racial tensions within the Black/African American community. The study included 60-120 minute interviews with 12 participants. Using intersectionality as a guide, the data were coded and utilized for thematic analysis. Then, an ethnodramatic performance engages readers. The goals of this study were to encourage policy changes, promote inclusivity for LGBQ employees at HBCUs, and provide an expansion to the body of literature in the field pertaining to the experiences of LGBQ faculty and administrators in higher education

    Gamification in E-Learning: game factors to strengthen specific English pronunciation features in undergraduate students at UPTC Sogamoso

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    Appendix A Characterization survey (104), Appendix B. EFL Students鈥 questionnaire (109), Appendix C. Characterization survey: data treatment question (113), Appendix D. Informed consent letter, English version (114), Appendix E. Carta de consentimiento informado, versi贸n en espa帽ol (117), Appendix F. Time Schedule (120), Appendix G. Sample Challenges at Moodle (126), Appendix H. Participants鈥 questionnaire results (128).La gamificaci贸n es un t茅rmino que suele denotar el uso de componentes del juego en situaciones no relacionadas con el juego en s铆 para crear experiencias de aprendizaje agradables, divertidas y motivadoras para los estudiantes (Werbach y Hunter, 2012). Por lo tanto, el an谩lisis de los factores b谩sicos de los juegos se convierte en algo esencial a la hora de definir y utilizar la gamificaci贸n como estrategia de mediaci贸n del ingl茅s como lengua extranjera para fortalecer rasgos espec铆ficos de pronunciaci贸n en los estudiantes de pregrado de la UPTC Sogamoso. El procedimiento de estudio se basa en la investigaci贸n acci贸n mediante la implementaci贸n de la estrategia de gamificaci贸n para la mediaci贸n en la pronunciaci贸n del ingl茅s, orientada a treinta estudiantes de diferentes programas de ingenier铆a, administraci贸n y tecnolog铆a con niveles heterog茅neos de dominio del ingl茅s. Las actividades se centran principalmente en la producci贸n de sonidos, el ritmo, el acento y la entonaci贸n, los rasgos de pronunciaci贸n segmental y suprasegmental. Los resultados arrojaron una evidente mejora en las caracter铆sticas segm茅ntales y suprasegmentales de la percepci贸n en la pronunciaci贸n de los participantes as铆 como la contribuci贸n del objetivo de los juegos a la instrucci贸n fon茅tica y fonol贸gica, la sensaci贸n en el juego a la motivaci贸n para mejorar la pronunciaci贸n, el reto establecido en los juegos a la actitud positiva de los participantes, y la sociabilidad a la exposici贸n practica de la pronunciaci贸n inglesa.Gamification is a relatively new term that often denotes the use of game components in situations unrelated to the game itself to create enjoyable, fun, and motivating learning experiences for students (Werbach and Hunter, 2012). Therefore, analyzing the games' basic factors becomes essential when defining and using gamification as a strategy for English as Foreign Language mediation to strengthen specific pronunciation features in UPTC Sogamoso undergraduate students. The study procedure is based on action research by implementing the gamification strategy for mediation in English pronunciation, oriented to thirty students from different engineering, management, and technology programs at heterogeneous levels of English proficiency. The activities mainly focus on sound production, rhythm, stress, and intonation, segmental and suprasegmental pronunciation features. The results showed an evident improvement in the segmental and suprasegmental features of the participants' pronunciation perception as well as the contribution of game goals to phonetics and phonological instruction, the game sensation to the motivation for pronunciation improvement, the game challenge to the participants' positive attitude, and the sociality to the English pronunciation exposure practice

    Globalisation and pollinators: pollinator declines are an economic threat to global food systems

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    1. Trade in animal-pollinated crops plays an important role in global food systems: in many low-income countries, export of pollinated crops such as coffee and cocoa plays a significant role in livelihoods, while food systems in many higher income nations depend on international trade in these crops to satisfy their local demands. Losses of pollination services therefore pose a significant risk to economies beyond the area directly affected. 2. Using a simple extension of a common economic model, we explore which countries are most affected by a loss of pollination services in three case study groups of 25 countries that are vulnerable to different risks: pesticide use, natural disasters and economic debts. 3. In all three cases, large, developed economies such as the United Kingdom, Germany and Japan, are estimated to suffer the greatest economic losses, even if pollinator losses only affect smaller, less-developed economies. 4. In cases where higher income countries are affected by pollinator losses, there is a significant shift in the value of global pollinated crop production towards other large, unaffected countries. 5. Our findings highlight the need for richer countries to invest in pollinator conservation beyond their own borders to maintain resilient food systems. We provide suggestions for further economic research to better understand and identify system vulnerabilities to pollinator losses

    Understanding interactions between Ramularia collo-cygni and barley leaf physiology to target improvements in host resistance and disease control strategy

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    Ramularia Leaf Spot (RLS) is an increasingly problematic disease of barley. Control options are limited as the causal fungus, Ramularia collo-cygni, has developed resistance to several of the major fungicide groups. Developing new methods for controlling this disease is therefore a priority. R. collo-cygni can grow systemically in barley plants from infected seed, without inducing visible symptoms. In the field, visible symptoms normally only appear after flowering. The relative contribution of the latent and symptomatic stages of the fungal lifecycle to reduction in barley yield is not currently known with any certainty. Two possibilities are that the effect of asymptomatic infection on pre-flowering photosynthetic activity, and the development of grain sink capacity, plays an important role; or that reduction in photosynthetic activity during grain filling, resulting from lesion development and loss of green leaf area, is the predominant factor. This research aimed to increase our understanding of the impact of different phases of the fungal lifecycle on barley photosynthesis and yield formation, to better target host resistance and disease control strategies. Controlled environment and field experiments were used to determine the relative effects of asymptomatic and symptom-expressing phases of R. collo-cygni infection on photosynthesis and yield formation in spring barley. In controlled environment experiments leaf photosynthetic activity was measured in seedlings inoculated with suspensions of R. collo-cygni mycelia. Measurements were made before and after visible symptom development using Infra-Red Gas Analysis (IRGA), chlorophyll fluorescence analysis and chlorophyll fluorescence imaging. No reduction in photosynthetic activity was observed in leaves infected with R. collo-cygni, compared to those of non- infected leaves, during the latent phase of infection. After the appearance of visible symptoms, photosynthetic activity within lesions reduced as the lesions developed. However, this did not lead to reductions in photosynthetic activity when measured across the whole leaf area, suggesting that for there to be a significant effect of disease on whole leaf photosynthetic activity, visible symptoms must develop into mature lesions and coalesce to cover larger areas of the leaf surface. In field experiments plots were treated with a full fungicide regime, left untreated, or inoculated with R. collo-cygni and treated with fungicide to which R. collo-cygni is resistant (the latter as a precaution against lack of natural RLS disease that year and/or other diseases developing on untreated plots). RLS was the only disease of significance that developed in untreated or inoculated plots. Symptoms first appeared after flowering, around Zadoks Growth Stage 72. Fungicide-treated plots remained free of disease. Chlorophyll fluorescence analysis of field plants showed no effect of infection on the maximum quantum efficiency of Photosystem II (Fv/Fm) before visible symptom development, consistent with results from controlled environment experiments. Grain yield of untreated and fungicide-treated plots was predicted from fixed common values of radiation use efficiency (RUE) and utilisation of soluble sugar reserves, and measured values of post-flowering healthy (green) leaf area light interception. Grain yields predicted from the difference in post-flowering light interception between fungicide-treated plants and untreated or inoculated plants displaying symptoms of RLS were comparable with the measured yield response to fungicide. This suggests that yield loss to RLS is primarily associated with a reduction in light capture during grain filling, resulting from lesion development and loss of green leaf area. Results from controlled environment and field experiments suggested that symptom expression was associated with leaf senescence. Further controlled environment experiments tested this relationship by using treatments to vary the onset and rate of leaf senescence. Seedlings that were treated with cytokinin to delay senescence after inoculation with suspensions of R. collo-cygni mycelia developed fewer lesions than control plants. Fungal growth, as measured by quantification of R. collo-cygni DNA in leaves, was also restricted in plants treated with cytokinin. Collectively these results suggest that prevention of visible symptom development, rather than prevention of asymptomatic growth, is the most important target for management of this disease. Control methods targeted at delaying senescence could be a useful avenue for further investigation
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