5,549 research outputs found
An empirical calibration of nebular abundances based on the sulphur emission lines
We present an empirical calibration of nebular abundances based on the strong
emission lines of [SII] and [SIII] in the red part of the spectrum through the
definition of a sulphur abundance parameter S23. This calibration presents two
important advantages against the commonly used one based on the optical oxygen
lines: it remains single-valued up to abundances close to solar and is rather
independent of the degree of ionization of the nebula.Comment: 10 pages, 8 figures. Accepted for publication in MNRA
Mate choice and reproductive strategies in recently diverged populations of the house mouse (Mus musculus domesticus)
Population divergence is an important process in the evolution of lineages and can occur rapidly through the interaction of random genetic drift with natural and sexual selection. While natural selection operates on differences in fitness with respect to the local environment, sexual selection acts on the reproductive success of individuals through pre- and postcopulatory mate choice. Recently separated populations of the Western European house mouse Mus musculus domesticus were investigated for mating preferences. The study system consisted of two populations, one sampled in the Cologne/Bonn region, referred to as the “German population” and one from the Massif Central, termed here the “French population”. These populations have been separated for at most 3,000 years. Although this time span is short in evolutionary terms, they already show genetic differentiation. To test whether population divergence is reflected in mate choice, I carried out four replicates of a long-term experiment, in which individually tagged mice of both populations were held for 6 month in a semi-natural enclosure. As controls, I conducted cage experiments, where females could choose between males of both populations during a 6 day period. Paternities in the enclosure populations were determined by microsatellite typing of all individuals and they were used as measures for mate choice and reproductive success. The frequent monitoring of the populations during which animals were examined individually allowed the assessment of their physical condition. Furthermore, I examined the influence of a selfish genetic element, the t haplotype, on pre- or postcopulatory mate choice for the different population backgrounds. Finally, I analyzed whether the population divergence is also reflected in relative frequencies of female strategies such as polyandry and communal breeding. Founder animals of the long-term experiment did not follow a consistent mate choice pattern, while individuals born in the enclosures showed a significant preference for partners who had a father from the same population as themselves. In the controlled cage experiment, there was no consistent preference pattern regarding population background. However, female littermates that grew up in the same cage chose males coming from one population, indicating an environmental influence. These findings are discussed in the context of behavioral and genomic imprinting. German and French founder animals differed slightly in reproductive success. Among the F1 individuals, the comparison of reproductive success between individuals with a mixed population background (i.e. with parents from different populations) versus animals with a pure background (i.e. with parents from the same population) revealed no significant differences. Nevertheless, when looking at the combination of measures for reproductive success, such as offspring number, number of mating events, and offspring per mating, in 5 out of 6 parameters “pure” individuals outperformed the “mixed” individuals, which might indicate a slight decrease in hybrid fitness. No different influences were detected between German, French and hybrid animals regarding the t haplotype or different frequencies of female multiple mating and communal breeding. Influences of the t haplotype were restricted to a slight decrease in offspring number in successful mating events between t/wt animals for all combinations of population backgrounds. Contrary to theoretical assumptions and other experiments, no evidence for an increased multiple mating frequency or avoidance of partners with t/wt was found. Polyandry and communal breeding seemed to be general strategies in females of pure as well as mixed population backgrounds, and both strategies increased in frequency with an increasing population density. Females displaying these strategies had a slightly higher reproductive success in semi-natural conditions: Mothers with litters sired by several males had a higher reproductive success than mothers with only single paternity litters. A higher reproductive success was also detected for females which grew up in communally reared litters. Summarizing the outcome of the study, the recently diverged populations do not vary in partner choice: no differences in mate choice or reproductive strategies were observed. However, females preferred mates that had fathers from the same population as themselves, a pattern which I will call the “father related assortative mating pattern”. This suggests the presence of cues which enable the differentiation between “one’s own population” and “the other population”. In addition, the results gave insights into the benefits of costly female reproductive strategies.List of Contents ............................................................................................................1 List of Figures and Tables............................................................................................3 Danksagung.................................................................................................................5 Zusammenfassung.......................................................................................................7 Abstract ........................................................................................................................9 Declaration .................................................................................................................11 1 General Introduction...........................................................................................12 1.1 Studying mate choice in the context of population divergence ..................12 1.2 The house mouse.......................................................................................13 1.2.1 The European Western house mouse as a model organism for evolutionary studies ...........................................................................................13 1.2.2 Mouse phylogeny ...............................................................................14 1.2.3 Life history of the house mouse..........................................................15 1.3 Aim of the study..........................................................................................16 2 Mate choice between individuals of two separated house mouse populations (M. m. domesticus)...........................................................................................................17 2.1 Introduction.................................................................................................17 2.2 Methods......................................................................................................19 2.2.1 Long-term Experiment ........................................................................19 2.2.2 Controlled female choice in a cage system........................................24 2.3 Results from the Long-term Experiment.....................................................26 2.3.1 Population development .....................................................................26 2.3.2 Paternity assignment ..........................................................................28 2.3.3 Assortative mate choice .....................................................................29 2.3.4 Reproductive success ........................................................................35 2.3.5 Multiple mating frequencies................................................................47 2.3.6 Social partner choice ..........................................................................48 2.3.7 Social status .......................................................................................49 2.4 Results from the Controlled Cage Experiment ...........................................52 2.5 Discussion ..................................................................................................53 2.5.1 Paternity analysis ...............................................................................53 2.5.2 Population Development ....................................................................54 2.5.3 Assortative mating ..............................................................................55 2.5.4 Reproductive success ........................................................................56 2.5.5 Relative fertilization success ..............................................................56 2.5.6 Relative testis weight..........................................................................57 2.5.7 Multiple paternity ................................................................................57 2.5.8 Communal breeding as a measure for social partner choice .............57 2.5.9 Fitness ................................................................................................58 2.6 Conclusion..................................................................................................58 3 The role of different molecular parameters for mate choice and individual reproductive strategies...............................................................................................59 3.1 Introduction.................................................................................................59 3.1.1 Background and focus of the investigation.........................................59 3.1.2 Mate choice and its benefits in house mice........................................59 3.1.3 Strategies related to reproduction ......................................................60 3.1.4 Genetic parameters involved in mate choice......................................62 3.2 Methods......................................................................................................64 3.3 Results .......................................................................................................67 3.3.1 Communal breeding ...........................................................................67 3.3.2 Multiple mating ...................................................................................70 3.3.3 Effects of the t haplotype....................................................................76 3.3.4 Parameters correlating with male reproductive success ....................83 3.4 Discussion ..................................................................................................85 3.4.1 Communal breeding ...........................................................................85 3.4.2 Multiple paternity ................................................................................87 3.4.3 Effects of the t Haplotype ...................................................................89 3.4.4 Parameters correlating with reproductive success .............................91 3.5 Conclusion..................................................................................................92 References.................................................................................................................93 Supplement ..............................................................................................................101 Supplement 1: Description Access Database ......................................................101 Overview tables................................................................................................101 Detailed description tblMice .............................................................................101 Digital Supplement...................................................................................................104 Erklärung..................................................................................................................105 Lebenslauf................................................................................................................10
La reescritura de la leyenda de Tristán e Iseo en "Cligès"
La obra "Cligès", de ChrĂ©tien de Troyes, ha sido tradicionalmente considerada por la crĂtica como una reescritura moralista de la leyenda de Tristán e Iseo. El nuevo sen aplicado por este poeta francĂ©s no solo se aplica en el sentido de una relectura del amor cortĂ©s más ortodoxa, sino tambiĂ©n en el de un mayor realismo literario, más racional y moderno en tĂ©rminos estilĂsticos. Amor, pasiĂłn y adulterio, bajo la pluma de ChrĂ©tien, se convierten en nuevos conceptos aptos para establecer una distancia e incluso una confrontaciĂłn contra el libertinaje poĂ©tico de sus coetáneos normandos
El Llibre de l'orde de cavalleria en el context sociocultural medieval
Ramon Llull va redactar el seu Llibre de l’orde de cavalleria sota la influència d’un temps i d’una mentalitat fortament marcats pel context sociocultural medieval. L’article explica com cal entendre la realitzaciĂł d’aquesta obra en funciĂł de l’etapa quaternĂ ria de l’Art lul·liana, amb les seves virtuts i els seus pecats; de la situaciĂł geopolĂtica del segle xiii, especialment tot allò relacionat amb la cavalleria, i dels tractats de cavalleria produĂŻts o coneguts a la Corona d’AragĂł de l’època
Motius folklòrics al Tristany i Iseut
L’article aplega i analitza els principals motius folklòrics de Tristany i Iseut i els classifica segons l’Ăndex del folklorista Stith Thompson
Broadening of HO rotational lines by collision with He atoms at low temperature
We report pressure broadening coefficients for the 21 electric-dipole
transitions between the eight lowest rotational levels of ortho-HO and
para-HO molecules by collisions with He at temperatures from 20 to 120 K.
These coefficients are derived from recently published experimental
state-to-state rate coefficients for HO:He inelastic collisions, plus an
elastic contribution from close coupling calculations. The resulting
coefficients are compared to the available experimental data. Mostly due to the
elastic contribution, the pressure broadening coefficients differ much from
line to line, and increase markedly at low temperature. The present results are
meant as a guide for future experiments and astrophysical observations.Comment: 2 figures, 2 table
Manuel Brunet i Josep M. de Sagarra: retrat d'una admiraciĂł literĂ ria
Sobre la relació entre l'escriptor barcelonà Josep M. de Sagarra i Castellarnau i el periodista vigatà Manuel Brunet i Solà destacats de la generació del periodisme català d'entreguerres. En el present article es pretén abordar la descripció de la relació personal i intel·lectual
entre aquests dos autors, especialment a partir dels anys trenta, fent especial èmfasi en el retrat de l'admiració literà ria professada pel primer envers el segon, al qual considerava -amb fonament- un dels grans autors de la literatura catalana del segle X
La familia, recurso comunitario básico
Desde que se ha producido la reforma psiquiátrica se ha instaurado un modelo de atención en el que el eje principal ha dejado de ser el hospital psiquiátrico (Salvador-Carulla, 2002), para pasar a un modelo comunitario avalado por la OMS y recogido por la Ley General de Sanidad (Ley 14/1986 de 25 de abril) donde el centro de salud es la referencia. A pesar de que era esperable que los efectos de la transferencia de funciones de los hospitales mentales tradicionales a los cuidados comunitarios mantuviera sin apenas cambios el descanso de la familia y de los cuidadores (Thornicroft, 2002), este fenómeno de compensación no parece haberse producido en nuestro medio, al no verse incrementado el esperado apoyo profesional a la familia..
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