578 research outputs found
Light, temperature and the induction of dormancy in 'Potamogeton crispus' and 'Potamogeton obtusifolius'
Dormancy in many aquatic angiosperms is characterized by the production of turions, specialized vegetative buds which function as both propagules and perennating organs. In temperate climate species, induction of dormancy is usually associated with short days, often in conjunction with low temperatures. By contrast, the turions of Potamogeton crispus are formed around midsummer and the species grows luxuriantly throughout the winter. The environmental factors controlling turion formation in Potamogeton crispus were investigated under natural and laboratory conditions. Potamogeton obtusifolius, a typical temperate climate species exhibiting autumnal turion production, was studied for comparative purposes. Phenological development of natural populations in two Scottish lakes was compared with seasonal measurements of temperature, daylength, underwater light attenuation and light quality (the red and far red wavelength bands). Temperature and photoperiod were identified as the primary environmental factors regulating turion formation in both species. Laboratory experiments confirmed the field observation that turions are produced by Potamogeton crispus in response to long days (greater than 12 to 16h) and high temperatures (greater than 16°C). In Potamogeton obtusifolius, turion production is associated with short days and high temperatures. Because of the complexity of the underwater light climate, the effect of light quantity (irradiance) and light quality on turion production could not be determined. Laboratory experiments showed that under inductive photoperiodic and temperature conditions, low red:far red ratios and low irradiance inhibited turion formation in Potamogeton crispus. The action of phytochrome in the perception of the long day photoperiodic signal and the quantitative effect of sucrose concentration on the magnitude of turion production in Potamogeton crispus was investigated. A model of phytochrome action in the control of photoperiodic and photomorphogenetic responses in aquatic angiosperms is presented and the role of turions in the life history of Potamogeton crispus and Potamogeton obtusifolius is assessed
A Self Study of Changing Art Education Pedagogy in Mid-Career: Possibilities, Impediments and Insights
When art teachers are asked to adopt a different teaching pedagogy, often little thought is given to the impact that those changes have on the lives of those teachers. This thesis answers the question: What are the possibilities and impediments of an experienced art teacher choosing to change art education pedagogy in mid-career? The author, a mid-career art educator investigates the experience of making a fundamental change to her teaching pedagogy. Drawing from the literature of holistic art education, pre-service elementary generalists in art methods courses, self-study methodology and grounded theory methods of analysis, this thesis documents the author’s transition between teaching styles.
Having successfully taught in a teacher-centered/authoritarian style for nearly 15 years, she rewrote her pedagogy based on the literature of holistic art education, emphasizing a more student-centered teaching method. She then attempted to apply this new pedagogy while teaching an art methods course for pre-service elementary generalist teachers. The structure of this study is based on weekly, audio-recorded self-interviews she conducted after each class. These audio-recordings were used to track her emotional and cognitive responses as she worked toward integrating her new teaching pedagogy into practice.
This study uncovers the feelings of vulnerability, stress and mental and physical fatigue the author experienced as a result from making these changes. Yet opportunities for growth are revealed as well. She gained new insights into the experiences of her students, a better understanding of how to navigate change in the classroom and a renewed sense of purpose to her teaching practice.
Drawing from these findings, the author presents a model for self-directed, holistic change to art education pedagogy that can help art teachers embrace and navigate change in their own classrooms.
This dissertation concludes with suggestions for future research in the following areas: the lives of mid-to-late career art educators whose voices are absent from the literature of art education; the notion of vulnerability in the lives of pre-service and early-career art teachers; and a longitudinal study on the long-term impact of holistic/student-centered art education pedagogy and elementary generalist teachers
Use of Enterococcus, BST and Sterols for Poultry Pollution Source Tracking in Surface and Groundwater
Portraits of women’s paid domestic-care labour: Ethnographic studies from globalizing India
Our introduction to this Special Issue draws out themes from all four articles which focus on India’s
domestic-care economy: women’s paid domestic labour, care work and surrogacy. Through fine-grained
ethnographic detail, all the articles nuance questions around agency and resistance, and actively challenge
the ‘passive victim’ stereotype that continues to be the primary imaginary in many representations of
domestic-care workers. We describe how the articles detail the intimacy, emotional labour and complex
spatial dynamics inherent within a sector that often involves working in the homes of others, caring for
children, and complex relationships with employers. Additionally, we show how care workers encounter
quotidian forms of bodily control, distancing, segregation, authority, stigma, coercion, punitive sanctions
and stark exploitation embedded in the intersections of class, caste, gender and ethnicity. To provide a
wider framing for the articles, we utilize this introduction to situate them within broader historical and
geographical contexts. Thus, we consider how Global Care Chains (GCCs), labour markets, migration,
and colonial/postcolonial considerations interplay in shaping the everyday lives of domestic care workers
in contemporary globalizing India
Human Development and Controlled Substance Prescribing in Ohio Counties
Background: Human development is a holistic measure of well-being. The American Human Development Index (AHDI) operationalizes the concept for the American context, using a composite measure of income, education, and health. This work presents the first county-level examination of AHDI for the state of Ohio and examines the relationship between human development and controlled substance prescribing.Methods: Publicly available data from the census and prior publications were compiled to calculate county-level AHDI for all 88 Ohio counties. Correlations were examined between AHDI and 4 classes of controlled substances, opioids, benzodiazepines, stimulants, and sedatives, using Pearson product moment correlation coefficient.Results: County AHDI scores ranged from 3.3 to 7.6, with mean and median values of 4.8. At the county level, human development is negatively correlated with opioid (r = -0.46, r2 = 0.22, P <0.0001) and benzodiazepine (r = -0.43, r2 = 0.18, P <0.0001) prescribing and positively associated with stimulant prescribing (r = 0.49, r2 = 0.24, P <0.0001). Neither sedative prescribing practices (r = 0.09, P = 0.40) nor median age (r = -0.09, P = 0.41) were significantly correlated with AHDI.Conclusion: There is a strong correlation between AHDI and prescribing of several classes of controlled substanc-es. Work remains to ascertain mechanisms and directionality of these relationships. Whether higher prescribing in areas with lower human development is an attempt to medicate health inequity or low human development is an additional manifestation of the opioid epidemic, this study underscores the necessity of pursuing equity in all policies
Prácticas de consumo acerca de la compra, almacenaje y preparación de aves de corral y huevos en países seleccionados del Norte y de Sur America: un estudio piloto
Antecedentes: Aves de corral, huevos, y sus productos representan un potencial peligro en la seguridad alimentaria. Prácticas de consumo relacionadas con estos alimentos han sido estudiadas en varios países, pero pocos datos existen de Latinoamérica. Objetivo: El objetivo de este estudio piloto fue proveer información de manera de caracterizar la compra, almacenaje, y preparación de aves de corral y huevos entres países: Argentina, Colombia, y Estados Unidos. Métodos: Consumidores (n=425 en total) en cada locación, completaron cuestionarios acerca del comercio de compra de aves de corral y huevos, condiciones de almacenamiento (e.j. refrigerador o freezer), preparación y prácticas de manipulación, y manipulación de sobras. Resultados: Los resultados indicaron que en Estados Unidos, la mayoría de los consumidores encuestados adquiere huevos almacenados en refrigeración, mientras que en Argentina (91%) y Colombia(84%) los huevos adquiridos estaban almacenados a temperatura ambiente. Asimismo, casi la totalidad delos consumidores en Estados Unidos almacenan los huevos en refrigeración, mientras que un 23% y un 45.9% de consumidores Argentinos y Colombianos, respectivamente almacenan huevos a temperatura ambiente, lo cual potencialmente significa una práctica no segura. Algunas prácticas sostienen posible contaminación cruzada, por ejemplo el lavado de aves y huevos previos a la cocción. Conclusiones: Los resultados muestran una primera comparación entre países de América sobre las prácticas de consumo de aves de corral y huevos, que servirán como base para futuras investigaciones y desarrollos de mensajes educacionales sobre seguridad alimentaria.Background: Poultry, eggs, and their products represent a potential food safety hazard. Although consumer practices related to these foods have been studied in various countries, little data exists from Latin America. Objective: The objective of this pilot study was to provide initial data to characterize consumers’ purchase, storage, handling, and preparation of poultry products and eggs in three countries: Argentina, Colombia, and USA. Methods: Consumers (n = 425 total) in each location completed a questionnaire about poultry products and egg purchase locations, storage conditions (i.e. refrigerator or freezer), preparation and handling practices, and managing leftovers. Results: The results indicated that in the USA most surveyed consumers purchased refrigerated eggs, whereas in Argentina (91%) and Colombia (84%) eggs typically were purchased at room temperature. Furthermore, almost all consumers in the USA stored eggs in the refrigerator, but 23% of Argentinian and 45.9% of Colombian consumers stored eggs at room temperature, which is potentially an unsafe practice. Some practices supported possible cross-contamination, for example washing raw eggs and poultry prior to cooking. Conclusions: These results are a first comparison across countries in the Americas of consumer poultry and egg practices and can serve as the basis for further research and development of food safety educational messages.Fil: Koppel, Kadri. Kansas State University; Estados UnidosFil: Sosa, Miriam Patricia. Provincia de Buenos Aires. Dirección General de Cultura y Educación. Instituto Superior Experimental de Tecnología Alimentaria. Departamento de Evaluación Sensorial de Alimentos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Gutierrez Gusman, Nelson. Universidad Surcolombiana; ColombiaFil: Cardinal, Paula. Provincia de Buenos Aires. Dirección General de Cultura y Educación. Instituto Superior Experimental de Tecnología Alimentaria. Departamento de Evaluación Sensorial de Alimentos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Godwin, Sandra L.. University of Tennessee; Estados UnidosFil: Cates, Sheryl C.. No especifíca;Fil: Chambers, Edgar. Kansas State University; Estados Unido
Systems genetics analysis of body weight and energy metabolism traits in Drosophila melanogaster
<p>Abstract</p> <p>Background</p> <p>Obesity and phenotypic traits associated with this condition exhibit significant heritability in natural populations of most organisms. While a number of genes and genetic pathways have been implicated to play a role in obesity associated traits, the genetic architecture that underlies the natural variation in these traits is largely unknown. Here, we used 40 wild-derived inbred lines of <it>Drosophila melanogaster </it>to quantify genetic variation in body weight, the content of three major metabolites (glycogen, triacylglycerol, and glycerol) associated with obesity, and metabolic rate in young flies. We chose these lines because they were previously screened for variation in whole-genome transcript abundance and in several adult life-history traits, including longevity, resistance to starvation stress, chill-coma recovery, mating behavior, and competitive fitness. This enabled us not only to identify candidate genes and transcriptional networks that might explain variation for energy metabolism traits, but also to investigate the genetic interrelationships among energy metabolism, behavioral, and life-history traits that have evolved in natural populations.</p> <p>Results</p> <p>We found significant genetically based variation in all traits. Using a genome-wide association screen for single feature polymorphisms and quantitative trait transcripts, we identified 337, 211, 237, 553, and 152 novel candidate genes associated with body weight, glycogen content, triacylglycerol storage, glycerol levels, and metabolic rate, respectively. Weighted gene co-expression analyses grouped transcripts associated with each trait in significant modules of co-expressed genes and we interpreted these modules in terms of their gene enrichment based on Gene Ontology analysis. Comparison of gene co-expression modules for traits in this study with previously determined modules for life-history traits identified significant modular pleiotropy between glycogen content, body weight, competitive fitness, and starvation resistance.</p> <p>Conclusions</p> <p>Combining a large phenotypic dataset with information on variation in genome wide transcriptional profiles has provided insight into the complex genetic architecture underlying natural variation in traits that have been associated with obesity. Our findings suggest that understanding the maintenance of genetic variation in metabolic traits in natural populations may require that we understand more fully the degree to which these traits are genetically correlated with other traits, especially those directly affecting fitness.</p
Children’s and adults’ use of fictional discourse and semantic knowledge for prediction in language processing
Using real-time eye-movement measures, we asked how a fantastical discourse context competes with stored representations of real-world events to influence the moment-by-moment interpretation of a story by 7-year-old children and adults. Seven-year-olds were less effective at bypassing stored real-world knowledge during real-time interpretation than adults. Our results suggest that children privilege stored semantic knowledge over situation-specific information presented in a fictional story context. We suggest that 7-year-olds’ canonical semantic and conceptual relations are sufficiently strongly rooted in statistical patterns in language that have consolidated over time that they overwhelm new and unexpected information even when the latter is fantastical and highly salient
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