The function of copulatory plugs in Caenorhabditis remanei: hints for female benefits

<p>Abstract</p> <p>Background</p> <p>Mating plugs that males place onto the female genital tract are generally assumed to prevent remating with other males. Mating plugs are usually explained as a consequence of male-male competition in multiply mating species. Here, we investigated whether mating plugs also have collateral effects on female fitness. These effects are negative when plugging reduces female mating rate below an optimum. However, plugging may also be positive when plugging prevents excessive forced mating and keeps mating rate closer to a females' optimum. Here, we studied these consequences in the gonochoristic nematode <it>Caenorhabditis remanei</it>. We employed a new CO₂-sedation technique to interrupt matings before or after the production of a plug. We then measured mating rate, attractiveness and offspring number.</p> <p>Results</p> <p>The presence of a mating plug did not affect mating rate or attractiveness to roving males. Instead, females with mating plugs produced more offspring than females without copulatory plugs.</p> <p>Conclusions</p> <p>Our experiment suggests that plugging might have evolved under male-male competition but represents a poor protection against competing males in our experiment. Even if plugging does not reduce mating rate, our results indicate that females may benefit from being plugged in a different sense than remating prevention.</p

Miniaturized differential scanning calorimeter with an integrated mass sensing system: first steps

In this paper, the first steps towards integrating a mass sensing system into an existing miniaturized ceramic DSC (differential scanning calorimetry) chip are presented. A vibration setup is developed based on the mass-dependent change in frequency of the DSC chip as an oscillating cantilever. A simulation model reveals that the resolution of the measurement can be improved by reducing the chip thickness. In this study, different measurement methods (acoustic, optical, and piezoresistive) are investigated. Three complete measurement systems are set up and evaluated with regard to their integration in the DSC chip. All presented measurement methods show promising results and already allow mass measurements with a resolution of 100 µg.</p

Montagegerechte Gestaltungsrichtlinien mittels Deep Learning

Die Anwendung von Deep Learning in der manuellen Montage birgt großes Potenzial, Montagezeiten zu reduzieren und Montagefehler zu vermeiden. Indem der Montageablauf mithilfe einer Kamera erfasst und die aufgezeichneten Bilder durch einen Objekterkennungsalgorithmus analysiert werden, lassen sich Position, Lage und Art der montierten Bauteile bestimmen. Daraus lassen sich wiederum Informationen über Arbeitsschritte, Montagefehler oder den aktuellen Zustand des Produkts ableiten, sodass die Mitarbeiter bei der Montage durch entsprechende Anweisungen unterstützt werden können. Es stellt sich jedoch die Frage, inwieweit gegenwärtige Produkte für den Einsatz von Deep Learning geeignet sind. Nur wenn die zu montierenden Bauteile sicher erkannt werden, ist der Einsatz in der manuellen Montage sinnvoll. Bestehende Gestaltungsrichtlinien adressieren diesen Aspekt bislang nicht. Im Forschungsprojekt wurde daher untersucht, welche Eigenschaften Produkte aufweisen sollten, um eine optimale Objekterkennung zu ermöglichen. Dazu wurden Hypothesen zu positiven und negativen Bauteileigenschaften hinsichtlich der Erkennungsgenauigkeit formuliert und in praktischen Versuchen überprüft. Dabei konnte gezeigt werden, dass alle untersuchten Objekte durch den eingesetzten Objekterkennungsalgorithmus sehr gut detektiert werden. Aus den vorliegenden Forschungsergebnissen lassen sich daher keine Einschränkungen in der Produktgestaltung ableiten

Evolutionary Psychology of Eating Disorders: An Explorative Study in Patients With Anorexia Nervosa and Bulimia Nervosa

Prior research on non-clinical samples has lent support to the sexual competition hypothesis for eating disorders (SCH) where the drive for thinness can be seen as an originally adaptive strategy for women to preserve a nubile female shape, which, when driven to an extreme, may cause eating disorders. Restrictive versus impulsive eating behavior may also be relevant for individual differences in allocation of resources to either mating effort or somatic growth, reflected in an evolutionary concept called “Life History Theory” (LHT). In this study, we aimed to test the SCH and predictions from LHT in female patients with clinically manifest eating disorders. Accordingly, 20 women diagnosed with anorexia nervosa (AN), 20 with bulimia nervosa (BN), and 29 age-matched controls completed a package of questionnaires comprising measures for behavioral features and attitudes related to eating behavior, intrasexual competition, life history strategy, executive functioning and mating effort. In line with predictions, we found that relatively faster life history strategies were associated with poorer executive functioning, lower perceived own mate value, greater intrasexual competition for mates but not for status, and, in part, with greater disordered eating behavior. Comparisons between AN and BN revealed that individuals with BN tended to pursue a “fast” life history strategy, whereas people with AN were more similar to controls in pursuing a “slow” life history strategy. Moreover, intrasexual competition for mates was significantly predicted by the severity of disordered eating behavior. Together, our findings lend partial support to the SCH for eating disorders. We discuss the implications and limitations of our study findings

Innovating carbon-capture biotechnologies through ecosystem-inspired solutions

Rising atmospheric carbon concentrations affect global health, the economy, and overall quality of life. We are fast approaching climate tipping points that must be addressed, not only by reducing emissions but also through new innovation and action toward carbon capture for sequestration and utilization (CCSU). In this perspective, we delineate next-generation biotechnologies for CCSU supported by engineering design principles derived from ecological processes inspired by three major biomes (plant-soil, deep biosphere, and marine). These are to interface with existing industrial infrastructure and, in some cases, tap into the carbon sink potential of nature. To develop ecosystem-inspired biotechnology, it is important to identify accessible control points of CO2 and CH4 within a given system as well as value-chain opportunities that drive innovation. In essence, we must supplement natural biogeochemical carbon sinks with new bioengineering solutions

Improving statistical machine translation of informal language: a rule-based pre-editing approach for French Forums

La barrière linguistique limite le partage de connaissances entre communautés sur les forums internet. La traduction automatique (TA), qui permettrait d'aborder cette limitation, rencontre de nombreuses difficultés avec les textes communautaires. Cette thèse vise à investiguer dans quelle mesure un processus de préédition automatique ou interactif utilisant une technologie à base de règles peut réduire ces difficultés et ainsi améliorer la TA statistique de textes de forums français. Nous étudions différentes transformations puis évaluons leur impact sur la TA. Au-delà d'une amélioration significative de la qualité de la TA, nous observons une réduction de l'effort technique et temporel de post-édition. Au travers d'une étude de faisabilité avec de vrais utilisateurs de forums, nous observons que la tâche de préédition est envisageable dans ce contexte. Finalement, nous confirmons la portabilité du processus de préédition développé dans ce travail vers d'autres systèmes de TA et pour des forums de différents domaines

Les Interlangues en TA : l'exemple de MedSLT

La stratégie par interlangue présente plusieurs avantages pour les systèmes de traduction automatique. Elle facilite notamment le développement de systèmes multilingues destinés à fournir des traductions entre de nombreuses paires de langues. La traduction ne se faisant pas individuellement pour chacune des paires de langues, mais via une représentation sémantique abstraite centrale, le nombre de modules à développer pour l'ajout d'une nouvelle langue est réduit. Dans ce travail, nous nous proposons d'étudier de plus près l'interlangue, en particulier sa lisibilité et compréhensibilité. Ces caractéristiques ont en effet une grande importance aussi bien pour le développement des ressources utilisées pour la traduction que pour l'évaluation des traductions elles-mêmes. Pour ce faire nous nous intéresserons de plus près au système MedSTL, développé à l'Université de Genève pour la traduction de dialogues de diagnostic médical, qui utilise une stratégie de traduction par interlangue