915 resultados para Natural Selection, Behavior, Ants, Personality
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Most studies on selection in plants estimate female fitness components and neglect male mating success, although the latter might also be fundamental to understand adaptive evolution. Information from molecular genetic markers can be used to assess determinants of male mating success through parentage analyses. We estimated paternal selection gradients on floral traits in a large natural population of the herb Mimulus guttatus using a paternity probability model and maximum likelihood methods. This analysis revealed more significant selection gradients than a previous analysis based on regression of estimated male fertilities on floral traits. There were differences between results of univariate and multivariate analyses most likely due to the underlying covariance structure of the traits. Multivariate analysis, which corrects for the covariance structure of the traits, indicated that male mating success declined with distance from and depended on the direction to the mother plants. Moreover, there was directional selection for plants with fewer open flowers which have smaller corollas, a smaller anther-stigma separation, more red dots on the corolla and a larger fluctuating asymmetry therein. For most of these traits, however, there was also stabilizing selection indicating that there are intermediate optima for these traits. The large number of significant selection gradients in this study shows that even in relatively large natural populations where not all males can be sampled, it is possible to detect significant paternal selection gradients, and that such studies can give us valuable information required to better understand adaptive plant evolution.
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We examined the relations between personality (Five-Factor Model), risky health behaviours, and perceptions of susceptibility to health risks among 683 university students. The hypothesis was that personality would affect perceptions of susceptibility to health risks in two ways: directly, irrespective of risky health behaviours, and indirectly, through the effects of personality on risky health behaviours. The students were surveyed about smoking, being drunk, drunk driving, risky sexual behaviour, and perceptions of susceptibility to related health risks. In path-analytical models we found the expected direct and indirect effects. The personality dimensions of Agreeableness and Conscientiousness had negative direct effects on perceptions of susceptibility as well as negative indirect effects through risky health behaviours. Neuroticism was the only personality dimension to show positive direct effects on perceptions of susceptibility as well as negative indirect effects.
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OBJECTIVES Bone replacement grafting materials play an important role in regenerative dentistry. Despite a large array of tested bone-grafting materials, little information is available comparing the effects of bone graft density on in vitro cell behavior. Therefore, the aim of the present study is to compare the effects of cells seeded on bone grafts at low and high density in vitro for osteoblast adhesion, proliferation, and differentiation. MATERIALS AND METHODS The response of osteoblasts to the presence of a growth factor (enamel matrix derivative, (EMD)) in combination with low (8 mg per well) or high (100 mg per well) bone grafts (BG; natural bone mineral, Bio-Oss®) density, was studied and compared for osteoblast cell adhesion, proliferation, and differentiation as assessed by real-time PCR. Standard tissue culture plastic was used as a control with and without EMD. RESULTS The present study demonstrates that in vitro testing of bone-grafting materials is largely influenced by bone graft seeding density. Osteoblast adhesion was up to 50 % lower when cells were seeded on high-density BG when compared to low-density BG and control tissue culture plastic. Furthermore, proliferation was affected in a similar manner whereby cell proliferation on high-density BG (100 mg/well) was significantly increased when compared to that on low-density BG (8 mg/well). In contrast, cell differentiation was significantly increased on high-density BG as assessed by real-time PCR for markers collagen 1 (Col 1), alkaline phosphatase (ALP), and osteocalcin (OC) as well as alizarin red staining. The effects of EMD on osteoblast adhesion, proliferation, and differentiation further demonstrated that the bone graft seeding density largely controls in vitro results. EMD significantly increased cell attachment only on high-density BG, whereas EMD was able to further stimulate cell proliferation and differentiation of osteoblasts on control culture plastic and low-density BG when compared to high-density BG. CONCLUSION The results from the present study demonstrate that the in vitro conditions largely influence cell behavior of osteoblasts seeded on bone grafts and in vitro testing. CLINICAL RELEVANCE These results also illustrate the necessity for careful selection of bone graft seeding density to optimize in vitro testing and provide the clinician with a more accurate description of the osteopromotive potential of bone grafts.
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Ocean acidification is predicted to affect marine ecosystems in many ways, including modification of fish behaviour. Previous studies have identified effects of CO2-enriched conditions on the sensory behaviour of fishes, including the loss of natural responses to odours resulting in ecologically deleterious decisions. Many fishes also rely on hearing for orientation, habitat selection, predator avoidance and communication. We used an auditory choice chamber to study the influence of CO2-enriched conditions on directional responses of juvenile clownfish (Amphiprion percula) to daytime reef noise. Rearing and test conditions were based on Intergovernmental Panel on Climate Change predictions for the twenty-first century: current-day ambient, 600, 700 and 900 µatm pCO2. Juveniles from ambient CO2-conditions significantly avoided the reef noise, as expected, but this behaviour was absent in juveniles from CO2-enriched conditions. This study provides, to our knowledge, the first evidence that ocean acidification affects the auditory response of fishes, with potentially detrimental impacts on early survival.
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La presente tesis investiga sobre la manera en que la arquitectura se ha construido para utilizar la luz natural, con el fin de aplicar estos conocimientos a la rehabilitación de edificios históricos. Para ello es necesario conocer aspectos técnicos en el uso de la luz, partiendo por comprender cuáles son los fenómenos físicos que debiéramos conocer los arquitectos para poder utilizarla adecuadamente. Es necesario también saber cómo es el comportamiento de los materiales frente a la luz y cómo utilizar¬los en el contexto rehabilitación. Dentro de los aspectos técnicos, se establece cuáles son las estrate¬gias, los sistemas y las tecnologías necesarias para la utilización de la luz en arquitectura, y se organiza esta información con el fin de hacerla clara, accesible y útil. Sin embargo, la luz no puede ser empleada en forma adecuada si no se conocen los requerimientos y las necesidades que el ser humano tiene respecto de ella, para habitar en forma confortable y salu¬dable. Es por eso que se establecen a su vez los requerimientos humanos respecto de la luz desde el punto de vista de sus características biológicas, su percepción y sus necesidades ergonómicas. Como la tesis se enmarca dentro de la problemática de la rehabilitación de edificios históricos, es necesario conocer cuál es la relación entre los procesos histórico-culturales y la técnica para utilizar la luz en la historia de la arquitectura. Se busca establecer la correlación entre historia y técnica, con el fin de responder en forma adecuada a los valores patrimoniales de un edificio histórico al alterar un aspecto tan importante como su iluminación natural. Con este conjunto de conocimientos técnicos, humanos e históricos establecidos en la primera parte de la tesis, se propone un protocolo de diseño para un proyecto de rehabilitación en cinco casos de estudio. Esta herramienta analiza el comportamiento actual de la luz para una determinada función, detecta los problemas lumínicos, establece criterios para la elección de soluciones y analiza el compor¬tamiento de estas soluciones. Finalmente compara los resultados lumínicos de las condiciones actua¬les y la solución propuesta. Por último, la investigación genera criterios que pueden ser aplicables a la normativa chilena de plani¬ficación territorial respecto del uso de la luz en contextos urbanos patrimoniales. ABSTRACT This thesis addresses how the architecture has been built to use natural light, in order to apply this knowledge to the historic buildings rehabilitation. This requires knowing technical aspects in the use of light, starting to understand what physical phenomena we, the architects, should know to use it properly. It is also necessary to know how materials behave in regards to light and how to use it in the rehabilitation context. Among the technical aspects, we should define strategies, systems and techno¬logies necessary for the use of light in architecture, and organize this information in order to make it clear, available and useful. However, light cannot be used properly if are not known requirements and needs that human beings have towards it, to live in comfortable and healthy way. That is why light human requirements are determined to know how light influences their cycles, perception and comfort. As the thesis is in frame of rehabilitation of historic building problem, it is necessary to know how is the relationship between historic-cultural processes and technology of light use, in the architecture history. It seeks to establish the correlation between History and technology, in order to give an ade¬quately answer to the heritage values of a historic building by altering an important aspect like its natural lighting. With this set of technical, human and historical knowledge, established in the first part of the thesis, a protocol is proposed for a rehabilitation project design in five study cases. This tool analyzes current behavior of light for a specifically function, detects lighting problems, establishes criteria for the selec¬tion of solutions and analyzes solution behaviors. Additionally, it compares results of current lighting conditions and the proposed solution. Finally this research generates criteria that may be applicable to Chilean territorial planning legislation, regarding use of light in patrimonial urban contexts.
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If behavioral isolation between species can evolve as a consequence of sexual selection within a species, then traits that are both sexually selected and used as a criterion of species recognition by females should be identifiable. The broad male head of the Hawaiian picture-winged fly Drosophila heteroneura is a novel sexual dimorphism that may be sexually selected and involved in behavioral isolation from D. silvestris. We found that males with broad heads are more successful in sexual selection, both through female mate choice and through aggressive interactions. However, female D. heteroneura do not discriminate against hybrids on the basis of their head width. Thus, this novel trait is sexually selected but is not a major contributor to species recognition. Our methods should be applicable to other species in which behavioral isolation is a factor.
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"Literature": p. 578-648.
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Interview Protocol Experience with cloud music services General experience with cloud services About their music collection Managing music collection General music listening behavior Mobile music consumption behavior Future of cloud music services Summary of Codebook
Predictors of adolescent sexual intentions and behavior: Attitudes, parenting, and neighborhood risk
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The current study was a cross-sectional examination of data collected during an HIV risk reduction intervention in south Florida. The purpose of the study was to explore the relationships between neighborhood stress, parenting, attitudes, and adolescent sexual intentions and behavior. The Theory of Planned Behavior was used as a model to guide variable selection and propose an interaction pathway between predictors and outcomes. Potential predictor variables measured for adolescents ages 13–18 (n=196) included communication about sex, parent-family connectedness, parental presence, parent-adolescent activity participation, attitudes about sex and condom use, neighborhood disorder, and exposure to violence. Outcomes were behavioral intentions and sexual behavior for the previous eight months. Neighborhood data was supplemented with ZIP Code level data from regional sources and included median household income, percentage of minority and Hispanic residents, and number of foreclosures. Statistical tests included t-tests, Pearson's correlations, and hierarchical linear regressions. Results showed that males and older adolescents reported less positive behavioral intentions than females and adolescents younger than 16. Intentions were associated with condom attitudes, sexual attitudes, and parental presence; unprotected sexual behavior was associated with parental presence. The best fit model for intentions included gender, sexual attitudes, condom attitudes, parental presence, and neighborhood disorder. The unsafe sexual behavior model included whether the participant lived with both natural parents in the previous year, and the percent of Hispanic residents in the neighborhood. Study findings indicate that more research on adolescent sexual behavior is warranted, specifically examining the differentials between variables that affect intentions and those that affect behavior. A focus on gender and age differences during intervention development may allow for better targeting and more efficacious interventions. Adding peer and media influences to the framework of attitudes, parenting, and neighborhood may offer more insight into patterns of adolescent sexual behavior risk.
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For thousands of years, people from a variety of philosophical, religious, spiritual, and scientific perspectives have believed in the fundamental unity of all that exists, and this belief appears to be increasingly prevalent in Western cultures. The present research was the first investigation of the psychological and interpersonal implications of believing in oneness. Self-report measures were developed to assess three distinct variants of the belief in oneness – belief in the fundamental oneness of everything, of all living things, and of humanity – and studies examined how believing in oneness is associated with people’s self-views, attitudes, personality, emotions, and behavior. Using both correlational and experimental approaches, the findings supported the hypothesis that believing in oneness is associated with feeling greater connection and concern for people, nonhuman animals, and the environment, and in being particularly concerned for people and things beyond one’s immediate circle of friends and family. The belief is also associated with experiences in which everything is perceived to be one, and with certain spiritual and esoteric beliefs. Although the three variations of belief in oneness were highly correlated and related to other constructs similarly, they showed evidence of explaining unique variance in conceptually relevant variables. Belief in the oneness of humanity, but not belief in the oneness of living things, uniquely explained variance in prosociality, empathic concern, and compassion for others. In contrast, belief in the oneness of living things, but not belief in oneness of humanity, uniquely explained variance in beliefs and concerns regarding the well-being of nonhuman animals and the environment. The belief in oneness is a meaningful existential belief that is endorsed to varying degrees by a nontrivial portion of the population and that has numerous implications for people’s personal well-being and interactions with people, animals, and the natural world.