1,721,102 research outputs found
Female house sparrows "count on" male genes: experimental evidence for MHC-dependent mate preference in birds
Full text linkAbstract Background Females can potentially assess the quality of potential mates using their secondary sexual traits, and obtain "good genes" that increase offspring fitness. Another potential indirect benefit from mating preferences is genetic compatibility, which does not require extravagant or viability indicator traits. Several studies with mammals and fish indicate that the genes of the major histocompatibility complex (MHC) influence olfactory cues and mating preferences, and such preferences confer genetic benefits to offspring. We investigated whether individual MHC diversity (class I) influences mating preferences in house sparrows (Passer domesticus). Results Overall, we found no evidence that females preferred males with high individual MHC diversity. Yet, when we considered individual MHC allelic diversity of the females, we found that females with a low number of alleles were most attracted to males carrying a high number of MHC alleles, which might reflect a mating-up preference by allele counting. Conclusions This is the first experimental evidence for MHC-dependent mating preferences in an avian species to our knowledge. Our findings raise questions about the underlying mechanisms through which birds discriminate individual MHC diversity among conspecifics, and they suggest a novel mechanism through which mating preferences might promote the evolution of MHC polymorphisms and generate positive selection for duplicated MHC loci.</p
Modulation and consistency of ultrasonic vocalizations in the Eastern European house mouse (Mus musculus musculus) and sensor data to improve detection of mild lameness in dairy cattle : functions and translational value
No full textPhD Arbeit - Veterinärmedizinische Universität Wien - 2023PhD thesis - University of Veterinary Medicine Vienna - 2023Research on the communication of house mice has largely focused on olfactory signals, whereas their acoustic signals have received relatively little attention until recent years. I investigated the expression and functions of chemosensory and acoustic signals of Eastern European house mice (Mus musculus subsp. musculus), and particularly the functions of male courtship vocalizations. Male mice emit ultrasonic vocalizations (USVs) during courtship, which potentially influence their mating and reproductive success; however, evidence for this hypothesis has been lacking. My aims were to determine the effect of male pheromones and courtship vocalizations on male reproductive success, and I focused my research on wild derived Mus musculus (henceforth “wild mice”). To determine what kind of information is contained in male USVs (signaling functions), which females could use to assess the state and identity of potential mates, I also investigated whether USVs reliably signal males\u27 sexual arousal and individual identity. Due to the enormous time and effort required for analyzing mouse vocalizations, I also collaborated on research aimed at developing better methods for automatic USV detection and classification. Below, I summarize the main aims and results from each of the chapters in my dissertation. The first chapter provides results from a study that we conducted to test the effect of chemical signals on reproductive success of wild house mice living in seminatural conditions. We found that males increased the excretion of certain volatile and involatile pheromones only once they became socially dominant and acquired a territory, and dominant males had higher reproductive success than subordinates. Females discriminated and showed a preferential attraction towards the urinary scent of dominant versus subordinate males, but they showed no preferences for male urine with higher concentrations of involatile major urinary proteins (MUPs). Our study provides the first results to show that pheromone production correlates with male reproductive success for any mammal. They also raise important caveats for studying the regulation and functions of the pheromones of male mice in laboratory conditions. The second chapter presents the results from an experiment that we conducted to test whether males alter the emission of USVs after exposure to a female (i.e., socio-sexual priming). Early studies on male laboratory mice suggested that exposure to a female, or female odor enhances the rate of male USV emission, and that USVs therefore provide a reliable indicator of sexual arousal and interest in mating; however, the evidence for this hypothesis has been mixed. In this study, we implemented an improved version of a method that we developed to improve detection of USVs (Automated Mouse Ultrasound Detector or AMUD), which is the first step during data processing. Our results show that the socio-sexual priming increased the number and the types of USVs that males emitted, and the effects were long-lasting. This study provides the first evidence for socio-sexual priming of USV emission in wild house mice and the first to show that priming enhances the diversity as well as the rate of male USV emission. The third chapter reports the results of an experiment in which we aimed to test whether mice modulate USV production depending upon the genetic relatedness of a potential mate, and whether courtship USV emission correlates with a breeding pair’s subsequent reproductive success. We found that courtship USVs are differently modulated in different consecutive social contexts (indirect and subsequent direct social contact) and that males increased the number and spectral complexity of vocalizations during direct interactions. In this latter context, USV number and modulation correlated with reproductive success and relatedness to the female partner: mating pairs of genetically unrelated individuals emitted USVs with higher duration and spectral complexity and showed a higher reproductive success compared to pairs that were closely related, whose USVs were shorter and spectrally simple and had a lower reproductive success. Our results provide the first evidence that mice modulate USV emission during courtship depending upon genetic relatedness of a potential mate and that USV emission (rate and types) correlate with their subsequent reproductive success. In the fourth chapter, our goal was to test the hypothesis that male courtship USVs provide cues of individual identity (individual vocal signatures). We first tested whether USVs change once males are provided with a female odor stimulus; and then we evaluated the variation in the quantity and quality of USVs within individuals versus among individuals over three consecutive weeks. The males rarely vocalized until presented with female odor, and then individual males consistently increased the number and spectral complexity of USVs. After the presentation of female odor, we found that the spectrotemporal features of male USVs differed between individuals and mice could be classified according to their “vocalizing style” with a striking difference between low versus high vocalizers. We found that some males have a distinct vocal repertoire that is repeatable over time and that some spectrotemporal features of their USV structure could potentially be used by conspecifics for individual recognition. This study provides the first evidence that male mice increase the numbers and types of USVs upon investigating female odor, and also the first evidence that male USVs contain individual signatures that are consistent over time. In the fifth chapter, we aimed to cross-validate findings from different strains of laboratory mice, and we analyzed the USV emission and the social behavior of three strains, commonly used in studies on neurodevelopmental disorders (NDDs). Our results showed strain differences in the number and duration of USVs, the onset of the peak in the calling rate during neonatal age, and also sex and strain differences in the number of vocalizations and repertoire composition during adulthood during same sex (i.e., female-female) and opposite-sex interactions. For the first time, we showed that: (1) there is a large phenotypic variation among strains in their social and communicative profile (i.e., number and duration of social investigations, vocalizations and spectrotemporal features of USVs); (2) strain C57/B6 emitted the lowest number of USVs that were spectrally simple and performed the lowest number of partner investigations; and (3) CD1 outbred strain showed an intermediate sociocommunicative profile compared to the two inbred strains. Our results highlight the differences in the behavior and vocalizations among strains of laboratory mice and importance of choosing the appropriate strain to conduct experiments on socio-communicative profiles in mice. In the sixth chapter, we developed a new method for automatically classifying different types of USVs, and compared its performance with other methods. Manual classification of USVs requires a tremendous amount of time, even for trained researchers, and therefore, we aimed to develop a new automatic USV classification method that is more reliable and generalizable than the current methods that are available. Our new method combines bootstrapping and ensemble machine learning. We found that it can accurately classify USVs into 12 different types (though accuracy was improved by pooling more types), and that it outperformed all other methods. This is the first study to systematically compare different automatic USV detection and classification methods and evaluate their performance, and we also provide a new method that now provides the state-of-the-art tool for USV classification. In summary, the main goals of my research were to investigate the adaptive functions of chemical and acoustic signals of house mice in terms of their effects on reproductive success. The results of these studies provide novel evidence that male pheromones and vocalizations influence reproductive success. To better understand why females are attracted to male USVs, and what kind of information they could provide to potential mates, I also tested hypotheses about their signaling functions. The results of these studies provide novel evidence that courtship USVs provide reliable information about a male\u27s individual identity (individual vocal signatures) and their state (sexual arousal). We presented a novel non-invasive tool to profile animal models used for NDDs and implemented a novel detection system and classification method for analyzing USVs in both, wild and domesticated mice. Results from studies on laboratory mice have provided many important and interesting findings, but as we have shown, the results from one strain cannot necessarily be extrapolated to other strains or their wild counter parts. Therefore, in the future, more studies on wild house mice are necessary to address questions about the ecological relevance and adaptive significance of their complex chemical and acoustic signals
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
- …
