925 resultados para morning
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The pH, VFA concentration, total gas and met hane production were determined in the rumen of four Sicilo- Sarde rams fitted with permanent canulas. Rams received a ration that included 1.5 kg DM of oat hay and were supplemented with one of four concentrates: CC (10% barley, 43.3% corn, 25% wheat bran, 17.7% soybean meal, 4% sheep Vitamin and Mineral Mixture (VMM)), SC (66% white sorghum, 30% faba, 4% sheep VMM); TC (71% triticale, 18% faba, 7%, soybean meal, 4% VMM) or BC (71.5% barley, 17.5% faba, 7% soybean meal and 4% VMM). 50 ml samples were taken before, 2, 5 and 8 hours after the morning meal. Total gas was determined on rumen content before the morning meal. The rumen pH was statistically different (P<0.05) before and 2 hours after the morning meal among concentrates feed. It was in favour of TC and BC (P<0.05) concentrates but was comparable at the end of the day. The concentration of VFA was significantly higher (P<0.05) for diets TC and BC following the meal and became comparable among concentrates thereafter. The proportion of acetate and butyrate acids evolved in the same way during the day regardless of the regimen. The total volu me of gas was different (P<0.05) among diets, the BC showed the highest value (87.00±17.29 ml) while the lowest value was found in the TC concentrate (56.58±13.06 ml). The CH4 production for the BC was significantly different (P<0.05) from that of TC. Quantities produced by the CC and SC were similar (22.08±4.18vs . 21.16±3.21).
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In this paper, a mathematical programming model and a heuristically derived solution is described to assist with the efficient planning of services for a set of auxiliary bus lines (a bus-bridging system) during disruptions of metro and rapid transit lines. The model can be considered static and takes into account the average flows of passengers over a given period of time (i.e., the peak morning traffic hour) Auxiliary bus services must accommodate very high demand levels, and the model presented is able to take into account the operation of a bus-bridging system under congested conditions. A general analysis of the congestion in public transportation lines is presented, and the results are applied to the design of a bus-bridging system. A nonlinear integer mathematical programming model and a suitable approximation of this model are then formulated. This approximated model can be solved by a heuristic procedure that has been shown to be computationally viable. The output of the model is as follows: (a) the number of bus units to assign to each of the candidate lines of the bus-bridging system; (b) the routes to be followed by users passengers of each of the origin–destination pairs; (c) the operational conditions of the components of the bus-bridging system, including the passenger load of each of the line segments, the degree of saturation of the bus stops relative to their bus input flows, the bus service times at bus stops and the passenger waiting times at bus stops. The model is able to take into account bounds with regard to the maximum number of passengers waiting at bus stops and the space available at bus stops for the queueing of bus units. This paper demonstrates the applicability of the model with two realistic test cases: a railway corridor in Madrid and a metro line in Barcelona Planificación de los servicios de lineas auxiliares de autobuses durante las incidencias de las redes de metro y cercanías. El modelo estudia el problema bajo condiciones de alta demanda y condiciones de congestión. El modelo no lineal resultante es resuelto mediante heurísticas que demuestran su utilidad. Se demuestran los resultados en dos corredores de las ciudades de Barcelona y Madrid.
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El incremento de la contaminación acústica se ha convertido en un problema medioambiental lo cual ha generado un aumento en la demanda del aislamiento de los edificios para lograr el confort acústico. Existen métodos de medición de aislamiento acústico a ruido aéreo de fachadas bajo ensayo “in situ” pero no para techos. El objetivo de esta investigación consiste en determinar el aislamiento acústico de prototipos de techos ecológicos multicapas adaptando la metodología recomendada por normas internacionales. Se propusieron cuatro prototipos de techos con distintos materiales naturales como especies vegetales y sustratos de fibra de coco, superpuestos sobre un techo base liviano. Al sustrato se le varió su espesor de 10 a 20 cm, sus condiciones seca o húmeda y su densidad: 100%, 66% y 33% fibra de coco. En los resultados se determinó que las especies vegetales no aportaron aislamiento, pero al incrementar el espesor y densidad del sustrato mejoró el aislamiento sonoro. También se determinó que el aislamiento acústico en condición seca fue mejor que en condición húmeda. Se planteó una metodología para determinar el aislamiento acústico a ruido aéreo en techos bajo ensayo “in situ” empleando el método global con altavoz, ésta se estructuró en tres partes: la primera describe el módulo experimental y la plataforma tecnológica; la segunda aborda procedimientos para medir los niveles de presión sonora, niveles de ruido de fondo y los tiempos de reverberación, en bandas de frecuencia de tercios de octava; en la tercera se explica el cálculo de los promedios de estos parámetros, así como también la diferencia de niveles estandarizada, el índice de reducción sonora aparente con sus valores globales y su incertidumbre. Así mismo, se determinó un algoritmo de predicción del aislamiento acústico, analizando los valores obtenidos en las mediciones “in situ” como la Diferencia de nivel estandarizada ponderada y el Índice ponderado de reducción sonora, los cuales se relacionaron con el peso y el espesor de los materiales de las diferentes multicapas. A través de un análisis de regresión se establecieron modelos para predecir la Diferencia de nivel estandarizada y el Índice de reducción sonora aparente en bandas de octavas. Los resultados del modelo propuesto son cercanos a los datos medidos “in situ”. Por otra parte, se realizaron mediciones térmicas en un módulo experimental y otro de referencia en tres períodos del día. En el módulo experimental se construyeron los prototipos de techos ecológicos y en el de referencia un techo de construcción tradicional, se compararon los resultados de ambos módulos y su interacción con la temperatura exterior. Se detectó que las temperaturas internas del módulo experimental en condición seca tienden a mantener sus valores durante todo el día, en horas de la mañana sus valores son superiores a los del módulo de referencia y temperatura exterior. Al mediodía y en la tarde las temperaturas internas del módulo experimental son inferiores a las del módulo de referencia, incrementándose esta última a medida que aumenta temperatura exterior. Finalmente, a partir de las mediciones “in situ” se realizaron cuatro modelos de correlación acústica-térmica, los tres primeros relacionando la temperatura y el nivel de presión sonora en tres momentos del día, en la tarde se aprecia que a medida que aumenta la temperatura aumentan los niveles de presión sonora. En el cuarto modelo se estableció una correlación acústica-térmica entre la resistencia térmica de los materiales de las multicapas con su índice de reducción sonora, obteniéndose un coeficiente de correlación moderado. La presente investigación plantea retos desde el punto de vista ambiental, permite cuantificar el aislamiento acústico de los techos y mejorar la calidad de vida en áreas urbanas; el empleo de los materiales de procedencia local como los utilizados fomenta el respeto por la naturaleza y producen un menor impacto ambiental. ABSTRACT Sound contamination increase has generated a raise in insulation demand of buildings in order to achieve a sound comfort, and this has become into an environmental problem. There are measurements methods for air borne soundproofing in facades through “in situ” test but there are not for roofs. The purpose of this research is to determine sound insulation of multilayer green roof prototypes following the methodology suggested by international standards. Four prototypes of roofs with different types of vegetation and overlapped coconut fiber substrates over a light roof were proposed. Thickness of substrate varied from 10 to 20 cm, as well as its dry a humid condition and its density: 100%, 66% y 33% of coconut fiber. Results determined that vegetation did not contribute to insulation but when increasing substrate’s thickness and density, sound insulation was improved. Likewise, it was determined that sound insulation in dry condition was greater than in humid condition. A methodology to determine airborne sound insulation in roofs through “in situ” test using a speaker global method was stated. This was structured in three parts: the first part describes the experimental module and the technological platform; the second one establishes the procedures to measure sound pressure levels; levels of background noise and time of reverberation in frequency bands of thirds of octave, and in the third part, averages of these parameters, as well as the difference of standardized levels, the apparent sound reduction with its global values and uncertainty were calculated. Likewise, a prediction algorithm of sound insulation was determined by analyzing values obtained in “in-situ” measures such as the difference of weighted standardized level and the weighted index of sound reduction which they were related to weight and thickness of different multilayer materials. Models to predict the standardized level difference and the apparent sound reduction index in bands of octaves were established by a regression analysis. Results for the proposed model are close to data measured “in situ”. On the other hand, thermal measures were done in an experimental module, as well as in another as for reference in three periods of the day. Green prototypes roofs were built in the experimental module and a traditional roof were built in the reference one. Results of both modules were compared as well as the interaction with outside temperature. Internal temperatures of the experimental module in dry condition tend to keep their values throughout the day; in the morning, its values are higher than those of the reference module and external temperatures. Finally, four models of sound-thermal correlation were done from measures “in situ”. The first three were related to temperature and sound pressure level in three moments of the day. In the afternoon, it is observed that when temperature increases, sound pressure levels increases too. In the fourth model, a sound and thermal correlation was established between thermal resistance of multilayer materials with their sound reduction index, and a moderated correlation coefficient was obtained. This research poses challenges from the environmental point of view, and it allows quantifying sound insulation of roofs as well as improving quality of life in urban areas; the use of local vegetation promotes respect for nature and it produces a smaller environmental impact as well.
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En el presente trabajo se ha analizado la situación actual de los hábitos de alimentación en los snack de media mañana en la población ESO y Bachillerato y los motivos de esta situación. También se ha estudiado la labor de los centros educativos y de los profesores respecto a la educación alimenticia de los estudiantes. Se ha realizado un estudio en dos centros escolares de la Comunidad de Madrid a los alumnos de ESO y Bachillerato, el Colegio Castilla de Torrejón de la Calzada y el IES Manuel Elkin Patarroyo, de las tendencias nutricionales durante los recreos. Se han obtenido hábitos y conductas alimenticias inadecuadas, por lo que se han propuesto varias aplicaciones educativas para emplear dentro del aula. Los centros educativos necesitan fomentar políticas acerca de educación nutricional que forme a los adolescentes en futuros adultos con hábitos de vida saludables. ABSTRACT The study analyzes the current situation of the eating habits in the mid-morning snack in adolescents at school population and the reasons for this situation. Regarding the type that eating students have, the work of schools regarding nutritional education is also studied. The study was conducted in two schools in the Comunidad de Madrid for ESO and Bachillerato students, (Colegio Castilla from Torrejón de la Calzada and IES Manuel Elkin Patarroyo from Parla), about nutritional trends during playground. The results showed inadequate eating habits and behaviors so it has proposed various educational proposals for use in the classroom. The schools need to promote policies on nutrition education that teach teenagers in future adults with healthy living habits
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online donde el contenido es creado por los propios usuarios mediante el uso de las tecnologías de la web 2.0, que facilitan la edición, la publicación y el intercambio de información, de tal manera que los social media están democratizando las comunicaciones. Según datos publicados por eMarketer, casi el 25% del total de la inversión publicitaria mundial para el 2014 estará dirigida a medios digitales. Los medios de comunicación tradicionales están sumidos desde algún tiempo en una profunda crisis. En los comienzos de Internet, los protagonistas de este sector han creído en la red como un medio de publicación de contenidos en una única dirección, esto es la web 1.0, personas conectándose a páginas web. El típico lector de revista y seminario se ha convertido en un nuevo consumidor con necesidades muy distintas. El lector de un medio tradicional se encuentra con contenido cerrado, sin posibilidad de ser filtrado, que busca dirigir su opinión. Con el método tradicional no es posible ni personalizar el contenido ni la experiencia de uso. De ahí el nacimiento de la web 2.0, personas conectándose a personas (redes sociales). En un futuro cercano, van a triunfar las empresas, sectores y marcas que sepan adaptarse a la llegada de los social media, y que además de desarrollar su línea de negocio habitual, se conviertan en plataformas para la conversación y la construcción de contenidos en colaboración. En este proyecto voy a desarrollar el caso particular de una empresa de telecomunicaciones con una estrategia que use los social media como plataforma de atención al cliente, y para interaccionar también con su almacén en DHL. Los servicios añadidos que dicha empresa de telecomunicaciones ofrece a sus seguidores, clientes externos e internos se pueden agrupar en las siguientes funcionalidades: Hacer un volcado del sistema de gestión de incidencias de una empresa de telecomunicaciones en las redes sociales, a través de mensajes privados. Dichos mensajes privados se enviarán a las páginas de Facebook y Twitter de los clientes. Seguimiento por parte del cliente de puestas en marcha de los nuevos servicios a través de mensajes privados en Facebook y Twitter. Mediante este servicio el cliente podrá comprobar a través de las redes sociales el estado de su pedido e intercambiar información de utilidad con la empresa. Desarrollar a través de las redes sociales una herramienta de marketing para interaccionar con los clientes y posibles seguidores. A través de los canales de los social media se proporciona a los seguidores información de valor sobre novedades del mercado de las telecomunicaciones, soporte técnico, dudas, consejos sobre implementaciones técnicas, equipos de telecomunicaciones,.etc.Es decir, crear una plataforma de conversación entre usuarios, que aporte a los seguidores conocimientos y soluciones útiles para la problemática de sus negocios. Usar Facebook como base de datos y medio de comunicación entre nuestra empresa de telecomunicaciones y el almacén externalizado en DHL. Supongo que la primera pregunta que debo responder sería, ¿por qué un cliente de una empresa de telecomunicaciones estaría interesado en seguir a su proveedor a través de redes sociales? Facebook tiene en 2014 1,28 billones de usuarios activos. Twitter, la cuarta plataforma social por número de usuarios tras Facebook, alcanzó los 255 millones de usuarios en los primeros meses de 2014. La segunda red social en número de seguidores es Youtube, con un billón de usuarios. El 61,5% de los usuarios de Facebook visita la red todos los días. Los twitteros envían 110 millones tweets por día, tienen fama de muy activos, especialmente por la mañana. En 60 días, se sube más contenido de vídeo a YouTube que el producido por las tres principales cadenas de televisión estadounidense durante 60 años. Como conclusión, las redes sociales están ganando cada día más terreno, es un entorno de comunicación bidireccional en auge cada vez más extendido, por lo cual los usuarios no tienen que dedicar tiempo extra a conocer la herramienta de atención al cliente de su empresa, al usar ésta un canal fácil, conocido, rápido, versátil y gratuito como son las redes sociales. ABSTRACT. Social media are platforms of online communication where content is created by users themselves using technologies of web 2.0, which facilitate the editing, publication and the exchange of information, so that the social media are democratizing communications. According to data published by eMarketer, nearly 25% of the total global ad spend for 2014 will target digital media. The traditional media are trapped for some time in deep crisis. In the early days of the internet, the players of the sector have believed in the network as a means of publishing content in a single direction, this is the web 1.0, connecting people to websites. The typical magazine reader has become a new consumer with very different needs. Traditional medium readers encounter a closed content, unable to be filtered, which seeks handle their opinion. The traditional method doesn’t allow to customize the content and user experience. Hence the birth of Web 2.0, connecting people to people. In the near future, will succeed companies, sectors and brands who can adapt to the advent of social media, and further to develop their line of business as usual, become platforms for conversation and building collaborative content. In this project I will develop the particular case of a telecommunications company with a strategy to use social media as a platform for Customer Service, and also to interact with DHL warehouse. The additional services that the company offers telecommunications followers, external and internal customers can be grouped into the following functionality: Make a dump of the incident management system of a telecommunications company in social networks through private messages. These private messages are sent Facebook and Twitter clients. Monitoring by the client launched new services through private messages on Facebook and Twitter. Through this service, customers can check through the social networks of your order status and share useful information with the company. Develop through social media as a marketing tool to interact with customers and potential followers.Our telco will provide to followers through social media channels valuable information on market developments in telecommunications, technical support, questions, advice on technical implementations, telecommunications equipment,etc. Then we create a platform for discussion between users, to provide followers useful knowledge and solutions to their business problems. Use Facebook as a database and means of communication between our telco and outsourced telecommunications in DHL warehouse. I guess the first question that must be answered is why a customer of a telecommunications company would be interested in following your provider via social networks. Facebook has 1.28 billion active users in 2014. Twitter, the fourth social platform for many users after Facebook reached 255 million users in the first months of 2014. The second social network on number of followers is YouTube, with a billion users. 61.5% of Facebook users visit the network every day. The twitter users send 110 million tweets per day, have a reputation for very active, especially in the morning. In 60 days, it is produced more video content to YouTube by the three major US television for 60 years. In conclusion, social networks are gaining more ground every day. It is an environment of two-way communication on the rise, so users do not have to spend extra time to learn the tool of Customer Care telco, by using this easy, known, fast, versatile and free channels as are social networks.
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Este estudo avaliou as alterações produzidas nos arcos dentais superiores de pacientes submetidos à Expansão Rápida da Maxila Assistida Cirurgicamente (ERMAC). A amostra utilizada foi composta de 50 modelos de gesso superiores de 18 pacientes, sendo seis do sexo masculino e 12 do sexo feminino, com média de idade de 23,3 anos. Para cada paciente foram preparados três modelos de gesso obtidos em diferentes fases: Inicial, antes do procedimento operatório (T1); três meses pós-expansão (travamento do expansor) e momento da remoção do aparelho expansor tipo Hyrax e colocação da placa removível de acrílico para contenção (T2); seis meses pós-expansão e momento de remoção da placa de acrílico (T3). O dispositivo expansor utilizado foi o disjuntor tipo Hyrax. O procedimento cirúrgico adotado foi a osteotomia lateral da maxila sem o envolvimento da lâmina pterigóide, osteotomia da espinha nasal à linha média dental (incisivos centrais superiores), separação da sutura palatina mediana por meio de cinzel e separação do septo nasal. O início da ativação ocorreu no terceiro dia pós-operatório, sendo ¼ de volta pela manhã e ¼ à noite, sendo que as ativações seguiram critérios clínicos para o controle da expansão. As medidas foram realizadas por meio da máquina de medição tridimensional (SAC), baseando-se nas alterações nos três planos (vertical, sagital e transversal) que ocorreram nos modelos de gesso. Concluiu-se que: 1. Houve um aumento estatisticamente significante nas distâncias transversais em todos os grupos de dentes (de incisivos centrais até segundos molares) de T1 para T2, demonstrando a efetividade do tratamento. De T2 para T3 não houve diferença estatisticamente significante para nenhuma variável, indicando, assim, estabilidade após seis meses do término da ERMAC; 2. Houve um aumento estatisticamente significante nas inclinações dos primeiros e segundos molares dos lados direito e esquerdo e dos segundos pré-molares apenas do lado esquerdo, sugerindo um comportamento assimétrico dos dentes avaliados; 3. Houve um aumento na largura palatina nos intervalos analisados, com diferenças estatisticamente significantes entre T1 x T2 e T1 x T3; 4. Não foram observadas diferenças estatisticamente significantes na profundidade palatina nos intervalos analisados.(AU)
Resumo:
Este estudo avaliou as alterações produzidas nos arcos dentais superiores de pacientes submetidos à Expansão Rápida da Maxila Assistida Cirurgicamente (ERMAC). A amostra utilizada foi composta de 50 modelos de gesso superiores de 18 pacientes, sendo seis do sexo masculino e 12 do sexo feminino, com média de idade de 23,3 anos. Para cada paciente foram preparados três modelos de gesso obtidos em diferentes fases: Inicial, antes do procedimento operatório (T1); três meses pós-expansão (travamento do expansor) e momento da remoção do aparelho expansor tipo Hyrax e colocação da placa removível de acrílico para contenção (T2); seis meses pós-expansão e momento de remoção da placa de acrílico (T3). O dispositivo expansor utilizado foi o disjuntor tipo Hyrax. O procedimento cirúrgico adotado foi a osteotomia lateral da maxila sem o envolvimento da lâmina pterigóide, osteotomia da espinha nasal à linha média dental (incisivos centrais superiores), separação da sutura palatina mediana por meio de cinzel e separação do septo nasal. O início da ativação ocorreu no terceiro dia pós-operatório, sendo ¼ de volta pela manhã e ¼ à noite, sendo que as ativações seguiram critérios clínicos para o controle da expansão. As medidas foram realizadas por meio da máquina de medição tridimensional (SAC), baseando-se nas alterações nos três planos (vertical, sagital e transversal) que ocorreram nos modelos de gesso. Concluiu-se que: 1. Houve um aumento estatisticamente significante nas distâncias transversais em todos os grupos de dentes (de incisivos centrais até segundos molares) de T1 para T2, demonstrando a efetividade do tratamento. De T2 para T3 não houve diferença estatisticamente significante para nenhuma variável, indicando, assim, estabilidade após seis meses do término da ERMAC; 2. Houve um aumento estatisticamente significante nas inclinações dos primeiros e segundos molares dos lados direito e esquerdo e dos segundos pré-molares apenas do lado esquerdo, sugerindo um comportamento assimétrico dos dentes avaliados; 3. Houve um aumento na largura palatina nos intervalos analisados, com diferenças estatisticamente significantes entre T1 x T2 e T1 x T3; 4. Não foram observadas diferenças estatisticamente significantes na profundidade palatina nos intervalos analisados.(AU)
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O trabalho emocionalmente desgastante dos profissionais das áreas de saúde implica não só a necessidade de uma habilitação acadêmica, mas, acima de tudo, uma adaptação, um equilíbrio emocional satisfatório, premissa básica para um serviço eficaz à saúde da população. Preocupando-se com o futuro profissional de Psicologia, esta pesquisa teve por finalidade verificar o grau de eficácia adaptativa de alunos do curso de Psicologia da Universidade Metodista de São Paulo, São Bernardo do Campo SP e, quando necessário, fazer-lhes indicação terapêutica. Este trabalho foi desenvolvido com a utilização da EDAO (Escala Diagnóstica Adaptativa Operacionalizada). Durante os anos de 1999 e 2000, foram feitas entrevistas diagnósticas individuais no NEPAP (Núcleo de Estudos, Pesquisa e Atendimento Psicológico), da UMESP, em 10% dos alunos do curso de Psicologia, dos períodos matutino e noturno. Os resultados foram analisados individualmente e inter-grupos com a finalidade de se obter um panorama geral do grau de eficácia adaptativa desses alunos. Com base nos resultados obtidos, verificou-se que embora alguns alunos apresentassem dificuldades nos setores Afetivo-Relacional e Produtividade, a grande maioria foi considerada normal .(AU)
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O trabalho emocionalmente desgastante dos profissionais das áreas de saúde implica não só a necessidade de uma habilitação acadêmica, mas, acima de tudo, uma adaptação, um equilíbrio emocional satisfatório, premissa básica para um serviço eficaz à saúde da população. Preocupando-se com o futuro profissional de Psicologia, esta pesquisa teve por finalidade verificar o grau de eficácia adaptativa de alunos do curso de Psicologia da Universidade Metodista de São Paulo, São Bernardo do Campo SP e, quando necessário, fazer-lhes indicação terapêutica. Este trabalho foi desenvolvido com a utilização da EDAO (Escala Diagnóstica Adaptativa Operacionalizada). Durante os anos de 1999 e 2000, foram feitas entrevistas diagnósticas individuais no NEPAP (Núcleo de Estudos, Pesquisa e Atendimento Psicológico), da UMESP, em 10% dos alunos do curso de Psicologia, dos períodos matutino e noturno. Os resultados foram analisados individualmente e inter-grupos com a finalidade de se obter um panorama geral do grau de eficácia adaptativa desses alunos. Com base nos resultados obtidos, verificou-se que embora alguns alunos apresentassem dificuldades nos setores Afetivo-Relacional e Produtividade, a grande maioria foi considerada normal .(AU)
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Photosynthesis and photoinhibition in field-grown rice (Oryza sativa L.) were examined in relation to leaf age and orientation. Two varieties (IR72 and IR65598-112-2 [BSI206]) were grown in the field in the Philippines during the dry season under highly irrigated, well-fertilized conditions. Flag leaves were examined 60 and 100 d after transplanting. Because of the upright nature of 60-d-old rice leaves, patterns of photosynthesis were determined by solar movements: light falling on the exposed surface in the morning, a low incident angle of irradiance at midday, and light striking the opposite side of the leaf blade in the afternoon. There was an early morning burst of CO2 assimilation and high levels of saturation of photosystem II electron transfer as incident irradiance reached a maximum level. However, by midday the photochemical efficiency increased again almost to maximum. Leaves that were 100 d old possessed a more horizontal orientation and were found to suffer greater levels of photoinhibition than younger leaves, and this was accompanied by increases in the de-epoxidation state of the xanthophyll cycle. Older leaves had significantly lower chlorophyll content but only slightly diminished photosynthesis capacity.
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We review the study of flower color polymorphisms in the morning glory as a model for the analysis of adaptation. The pathway involved in the determination of flower color phenotype is traced from the molecular and genetic levels to the phenotypic level. Many of the genes that determine the enzymatic components of flavonoid biosynthesis are redundant, but, despite this complexity, it is possible to associate discrete floral phenotypes with individual genes. An important finding is that almost all of the mutations that determine phenotypic differences are the result of transposon insertions. Thus, the flower color diversity seized on by early human domesticators of this plant is a consequence of the rich variety of mobile elements that reside in the morning glory genome. We then consider a long history of research aimed at uncovering the ecological fate of these various flower phenotypes in the southeastern U.S. A large body of work has shown that insect pollinators discriminate against white phenotypes when white flowers are rare in populations. Because the plant is self-compatible, pollinator bias causes an increase in self-fertilization in white maternal plants, which should lead to an increase in the frequency of white genes, according to modifier gene theory. Studies of geographical distributions indicate other, as yet undiscovered, disadvantages associated with the white phenotype. The ultimate goal of connecting ecology to molecular genetics through the medium of phenotype is yet to be attained, but this approach may represent a model for analyzing the translation between these two levels of biological organization.
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The level of mRNAs derived from the plastid-encoded psbD light-responsive promoter (LRP) is controlled by a circadian clock(s) in wheat (Triticum aestivum). The circadian oscillations in the psbD LRP mRNA level persisted for at least three cycles in continuous light and for one cycle in continuous dark, with maxima in subjective morning and minima in subjective early night. In vitro transcription in chloroplast extracts revealed that the circadian cycles in the psbD LRP mRNA level were dominantly attributed to the circadian-regulated transcription of the psbD LRP. The effects of various mutations introduced into the promoter region on the psbD LRP activity in vitro suggest the existence of two positive elements located between −54 and −36, which generally enhance the transcription activity, and an anomalous core promoter structure lacking the functional “−35” element, which plays a crucial role in the circadian fluctuation and light dependency of psbD LRP transcription activity.
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Regulation of rhythmic peaks in levels of endogenous gibberellins (GAs) by photoperiod was studied in the short-day monocot sorghum (Sorghum bicolor [L.] Moench). Comparisons were made between three maturity (Ma) genotypes: 58M (Ma1Ma1, Ma2Ma2, phyB-1phyB-1, and Ma4Ma4 [a phytochrome B null mutant]); 90M (Ma1Ma1, Ma2Ma2, phyB-2phyB-2, and Ma4Ma4); and 100M (Ma1Ma1, Ma2Ma2, PHYBPHYB, and Ma4Ma4). Plants were grown for 14 d under 10-, 14-, 16-, 18-, and 20-h photoperiods, and GA levels were assayed by gas chromatography-mass spectrometry every 3 h for 24 h. Under inductive 10-h photoperiods, the peak of GA20 and GA1 levels in 90M and 100M was shifted from midday, observed earlier with 12-h photoperiods, to an early morning peak, and flowering was hastened. In addition, the early morning peaks in levels of GA20 and GA1 in 58M under conditions allowing early flowering (10-, 12-, and 14-h photoperiods) were shifted to midday by noninductive (18- and 20-h) photoperiods, and flowering was delayed. These results are consistent with the possibility that the diurnal rhythm of GA levels plays a role in floral initiation and may be one way by which the absence of phytochrome B causes early flowering in 58M under most photoperiods.
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The chicken pineal gland contains the autonomous circadian oscillator together with the photic-input pathway. We searched for chicken pineal genes that are induced by light in a time-of-day-dependent manner, and isolated chicken homolog of bZIP transcription factor E4bp4 (cE4bp4) showing high similarity to vrille, one of the Drosophila clock genes. cE4bp4 was expressed rhythmically in the pineal gland with a peak at very early (subjective) night under both 12-h light/12-h dark cycle and constant dark conditions, and the phase was nearly opposite to the expression rhythm of cPer2, a chicken pineal clock gene. Luciferase reporter gene assays showed that cE4BP4 represses cPer2 promoter through a E4BP4-recognition sequence present in the 5′-flanking region, indicating that cE4BP4 can down-regulate the chick pineal cPer2 expression. In vivo light-perturbation studies showed that the prolongation of the light period to early subjective night maintained the high level expression of the pineal cE4bp4, and presumably as a consequence delayed the onset of the induction of the pineal cPer2 expression in the next morning. These light-dependent changes in the mRNA levels of the pineal cE4bp4 and cPer2 were followed by a phase-delay of the subsequent cycles of cE4bp4/cPer2 expression, suggesting that cE4BP4 plays an important role in the phase-delaying process as a light-dependent suppressor of cPer2 gene.
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People’s health and well-being may be determined by the interaction of endogenous and external rhythms. Late chronotypes should become anxious because of the demand to perform tasks in a society oriented preferentially to morning work. In this study, we examined the relationship between morningness and anxiety in 559 adults (age range 40–63 years) from rural environments who completed morningness–eveningness and anxiety measures. Results indicated a negative correlation between morningness and anxiety in women, but not in men, suggesting the relevance of gender-related variables. When demographic characteristics were considered, women’s anxiety was predicted by low educational level and eveningness, whereas men’s anxiety was predicted by being single, having children, being unemployed, and eveningness. Some hypotheses of gender-related social roles are postulated as a possible explanation of the results.