102 research outputs found

    Molecular genetic evidence for mixed maternity in broods of the Coal Tit Parus ater

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    Mittels molekulargenetischer Elternschaftsanalyse wurde eine niedrige Rate gemischter Mutterschaften in Bruten der sozial monogamen Tannenmeise nachgewiesen, einer Art, die sich durch hohe Fremdvaterschaftsraten auszeichnet. Gemischte Mutterschaften wurden in vier (= 0,8 %) von 483 Bruten entdeckt und nur für zehn (= 0,3 %) von 3563 erfolgreich genotypisierten Nachkommen wurde die Putativmutter von der genetischen Mutterschaft ausgeschlossen. In Anbetracht dieser sehr niedrigen Rate kann in evolutionsbiologischen Studien der soziale Fortpflanzungserfolg mit dem genetischen Fortpflanzungserfolg für Weibchen der Tannenmeise ohne weiteres gleichgesetzt werden. Die Putativväter wurden ebenfalls in allen Fällen von der genetischen Elternschaft ausgeschlossen, was Quasiparasitismus als Erklärung für gemischte Mutterschaften ausschließt. In einem Fall konnten die Partner eines Brutpaares, das zeitgleich in der Nähe eine eigene Brut aufzog, zweifelsfrei als die genetischen Eltern eines einzelnen Nachkommen identifiziert werden. Mögliche Ursachen für das Auftreten gemischter Mutterschaften bei der Tannenmeise schließen die Übernahme von Nistkästen samt begonnenen Gelegen nach dem Tod oder Abwandern der Vorbesitzer und innerartlichen Brutparasitismus ein.Molecular genetic analysis of parentage revealed a low frequency of mixed maternity in broods of the Coal Tit, a socially monogamous passerine with a high frequency of extra-pair paternity. Mixed maternity was detected in four (= 0.8 %) out of 483 analysed broods. For ten (= 0.3 %) out of 3563 successfully genotyped offspring the attending putative (social) mother was excluded from genetic parentage. Given the very low frequency of mixed maternity, social reproductive success can conveniently be equated with genetic reproductive success for female Coal Tits in evolutionary studies. Attending putative fathers were excluded from genetic parentage in all cases, too, ruling out quasi-parasitism as a mechanistic explanation for mixed maternity. In one case, the pair members from an adjacent territory were unequivocally identified as the genetic parents of a single offspring (they were simultaneously attending their own brood). Possible mechanisms leading to mixed maternity broods in the Coal Tit may include nest/clutch take-over and intraspecific brood parasitism and their respective relevance is briefly discussed

    Sperm velocity in a promiscuous bird across experimental media of different viscosities

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    Schmoll T, Rudolfsen G, Schielzeth H, Kleven O. Sperm velocity in a promiscuous bird across experimental media of different viscosities. Proceedings of the Royal Society B: Biological Sciences. 2020;287(1931): 20201031.In species with internal fertilization, the female genital tract appears challenging to sperm, possibly resulting from selection on for example ovarian fluid to control sperm behaviour and, ultimately, fertilization. Few studies, however, have examined the effects of swimming media viscosities on sperm performance. We quantified effects of media viscosities on sperm velocity in promiscuous willow warblers Phylloscopus trochilus. We used both a reaction norm and a character-state approach to model phenotypic plasticity of sperm behaviour across three experimental media of different viscosities. Compared with a standard medium (Dulbecco's Modified Eagle Medium, DMEM), media enriched with 1% or 2% w/v methyl cellulose decreased sperm velocity by up to about 50%. Spermatozoa from experimental ejaculates of different males responded similarly to different viscosities, and a lack of covariance between elevations and slopes of individual velocity-by-viscosity reaction norms indicated that spermatozoa from high- and low-velocity ejaculates were slowed down by a similar degree when confronted with high-viscosity environments. Positive cross-environment (1% versus 2% cellulose) covariances of sperm velocity under the character-state approach suggested that sperm performance represents a transitive trait, with rank order of individual ejaculates maintained when expressed against different environmental backgrounds. Importantly, however, a lack of significant covariances in sperm velocity involving a cellulose concentration of 0% indicated that pure DMEM represented a qualitatively different environment, questioning the validity of this widely used standard medium for assaying sperm performance. Enriching sperm environments along ecologically relevant gradients prior to assessing sperm performance will strengthen explanatory power of in vitro studies of sperm behaviour

    Differential sperm expenditure reveals a possible role for post-copulatory sexual selection in a lekking moth

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    Cordes N, Yiğit A, Engqvist L, Schmoll T. Differential sperm expenditure reveals a possible role for post-copulatory sexual selection in a lekking moth. Ecology and Evolution. 2013;3(3):503-511

    Extra-pair paternity and sperm length variation in a far northern Great Tit (Parus major) population

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    Extra-pair paternity is common among socially monogamous bird species and considered an important driver of post-copulatory sexual selection on ejaculate traits including sperm traits. Patterns of extra-pair paternity and sperm size both show substantial variation among populations, yet we know little about the expression of these key reproductive traits at high latitudes. Here we report patterns of extra-pair paternity and describe variation in sperm dimensions in a Norwegian population of the socially monogamous Great Tit (Parus major) breeding beyond the polar circle at 69° northern latitude. Across six study years, we detected extra-pair paternity in 19.2% of 26 broods, and on average 4.7% of nestlings per brood were extra-pair offspring. As expected from results of previous intraspecific analyses of latitudinal variation in extra-pair paternity rates, the observed rate of extra-pair offspring was low in comparison to published estimates from more southern Great Tit populations (range: 2.9 − 20.4%). Our results therefore support a pattern of decreasing levels of extra-pair paternity with increasing latitude in this species also for extremely high latitudes. Overall mean sperm total length amounted to 97.5 ± 0.6 (SE) μm and 30.6% of the total phenotypic variation in sperm total length was explained by differences among sperm samples. The among-sample coefficient of variation in mean sperm total length per sample was 1.93%. Using previous comparative work as a yardstick, this value is substantially lower than expected for the observed frequency of 4.7% extra-pair offspring. Extra-pair copulation · Latitudinal variation · Passerine · Promiscuity · Social monogamy · Sperm morphologyExtra-pair paternity and sperm length variation in a far northern Great Tit (Parus major) populationpublishedVersio

    Sex-specific repeatabilities and effects of relatedness and mating status on copulation duration in an acridid grasshopper

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    Haneke-Reinders M, Reinhold K, Schmoll T. Sex-specific repeatabilities and effects of relatedness and mating status on copulation duration in an acridid grasshopper. Ecology and Evolution. 2017;7(10):3414-3424.In species with direct sperm transfer, copulation duration is a crucial trait that may affect male and female reproductive success and that may vary with the quality of the mating partner. Furthermore, traits such as copulation duration represent the outcome of behavioral interactions between the sexes, for which it is important—but often difficult—to determine which sex is in phenotypic control. Using a double-mating protocol, we compared copulation durations between (1) virgin and nonvirgin and (2) sibling and nonsibling mating pairs in rufous grasshoppers Gomphocerippus rufus. Nonvirgin copulations took on average approximately 30% longer than virgin copulations, whereas relatedness of mating partners was not a significant predictor of copulation duration. Longer nonvirgin copulations may represent a male adaptation to sperm competition if longer copulations allow more sperm to be transferred or function as postinsemination mate guarding. The absence of differences between pairs with different degrees of relatedness suggests no precopulatory or preinsemination inbreeding avoidance mechanism has evolved in this species, perhaps because there is no inbreeding depression in this species, or because inbreeding avoidance occurs after copulation. Controlling for the effects of male and female mating status (virgin vs. nonvirgin) and relatedness (sibling vs. nonsibling), we found significant repeatabilities (R) in copulation duration for males (R = 0.33; 95% CI: 0.09–0.55) but not for females (R = 0.09; 95% CI: 0.00–0.30). Thus, copulation durations of males more strongly represent a nontransient trait expressed in a consistent manner with different mating partners, suggesting that some aspect of the male phenotype may determine copulation duration in this species. However, overlapping confidence intervals for our sex-specific repeatability estimates indicate that higher sampling effort is required for conclusive evidence

    Male social niche conformance? Effects of manipulated opportunity for extra-pair mating on behavior and hormones of male zebra finches

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    Success in sperm competition is an important determinant of male fitness in mating systems with female multiplemating. Thus, sperm competition risk represents a key dimension of the male social environment to which in-dividual males are expected to adaptively adjust their reproductive phenotype. Such adaptive phenotypicadjustment we here refer to as male social niche conformance. In this pre-registered study, we investigated howmale zebra finches, Taeniopygia guttata, adjust their behavior to sperm competition risk. We experimentallymanipulated the opportunity for extra-pair mating to create two levels of sperm competition risk: 1) Single-pair,no sperm competition risk; 2) Double-pair, sperm competition risk. We compared male courtship, mate guarding,copulation rates, and aggression between the treatment groups. To identify hormonal correlates of malebehavioral adjustment, we measured plasma testosterone and corticosterone levels before and after the socialtreatment started. Contrary to our pre-registered predictions, males from the Double-pair treatment groupdecreased courtship rates compared to those from the Single-pair group, and Double-pair males responded lessaggressively towards intruders than Single-pair males. Testosterone levels decreased over the breeding cycle, butsocial treatment had no effect on either testosterone or corticosterone levels. Our results indicate that male zebrafinches do not intensify courtship or competitive reproductive behaviors, or upregulate key hormones whenanother breeding pair is present. Although we found no evidence for the predicted adaptive behavioral responsesto sperm competition risk, we show that male zebra finches plastically adjust their behavior to their socialenvironmen

    No Evidence for Pre-Copulatory Sexual Selection on Sperm Length in a Passerine Bird

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    There is growing evidence that post-copulatory sexual selection, mediated by sperm competition, influences the evolution of sperm phenotypes. Evidence for pre-copulatory sexual selection effects on sperm traits, on the other hand, is rather scarce. A recent paper on the pied flycatcher, Ficedula hypoleuca, reported phenotypic associations between sperm length and two sexually selected male traits, i.e. plumage colour and arrival date, thus invoking pre-copulatory sexual selection for longer sperm. We were unable to replicate these associations with a larger data set from the same and two additional study populations; sperm length was not significantly related to either male plumage colour or arrival date. Furthermore, there was no significant difference in sperm length between populations despite marked differences in male plumage colour. We also found some evidence against the previously held assumption of longer sperm being qualitatively superior; longer sperm swam at the same speed as shorter sperm, but were less able to maintain speed over time. We argue that both empirical evidence and theoretical considerations suggest that the evolution of sperm morphology is not primarily associated with pre-copulatory sexual selection on male secondary sexual traits in this or other passerine bird species. The relatively large between-male variation in sperm length in this species is probably due to relaxed post-copulatory sexual selection

    Auto-tuned thermal control on stratospheric balloon experiments

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    Balloon-borne experiments present unique thermal design challenges, which are a combination of those present for both space and ground experiments. Radiation and conduction are the predominant heat transfer mechanisms with convection effects being minimal and difficult to characterize at 35-40 km. This greatly constrains the thermal design options and makes predicting flight thermal behaviour very difficult. Due to the limited power available on long duration balloon flights, efficient heater control is an important factor in minimizing power consumption. SuperBIT, or the Super-Pressure Balloon-borne Imaging Telescope, aims to study weak gravitational lensing using a 0.5m modified Dall-Kirkham telescope capable of achieving 0.02" stability and capturing deep exposures from visible to near UV wavelengths. To achieve the theoretical stratospheric diffraction-limited resolution of 0.25", mirror deformation gradients must be kept to within 20 nm. The thermal environment must be stable on time scales of an hour and the thermal gradients on the telescope must be minimized. During its 2018 test-flight, SuperBIT will implement two types of thermal parameter solvers: one for post-flight characterization and one for in-flight control. The payload has 85 thermistors as well as pyranometers and far-infrared sensors which will be used post-flight to further understand heat transfer in the stratosphere. This document describes the in-flight thermal control method, which predicts the thermal circuit of components and then auto-tunes the heater PID gains. Preliminary ground testing shows the ability to control the components to within 0.01 K

    Impact of geography on prognostic outcomes of 21,509 patients with metastatic colorectal cancer enrolled in clinical trials: an ARCAD database analysis

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    Impact of geography on prognostic outcomes of 21,509 patients with metastatic colorectal cancer enrolled in clinical trials: an ARCAD database analysis Show less Jun Yin*, Shaheenah Dawood*, Romain Cohen, Jeff Meyers, John Zalcberg, Takayuki Yoshino, Matthew Seymour, Tim Maughan, Leonard Saltz, Eric Van Cutsem, Alan Venook, Hans-Joachim Schmoll, Richard Goldberg, Paulo Hoff, J. Randolph Hecht, Herbert Hurwitz, Cornelis Punt, Eduard Diaz Rubio, Miriam Koopman, Chiara Cremolini, Volker Heinemann, Christophe Tournigard, Carsten Bokemeyer, Charles Fuchs, Niall Tebbutt, John Souglakos, Jean-Yves Doulliard, Fairooz Kabbinavar, Benoist Chibaudel, Aimery de Gramont, Qian Shi, Axel Grothey, Richard AdamsFirst Published June 30, 2021 Research Article https://doi.org/10.1177/17588359211020547 Article information Article has an altmetric score of 7 Open AccessCreative Commons Attribution, Non Commercial 4.0 License Article Information Volume: 13 Article first published online: June 30, 2021; Issue published: January 1, 2021 Received: December 29, 2020; Accepted: May 05, 2021 Jun Yin* Department of Health Sciences Research, Mayo Clinic, 200 First Street, SW Rochester, MN 55905, USA Shaheenah Dawood* Mediclinic City Hospital: North Wing, Dubai Health Care City, Dubai UAE Romain Cohen Department of Health Sciences Research, Mayo Clinic, Rochester, MN, USA Jeff Meyers Department of Health Sciences Research, Mayo Clinic, Rochester, MN, USA John Zalcberg School of Public Health and Preventative Medicine, Monash University, Melbourne, Australia Takayuki Yoshino Department of Gastrointestinal Oncology, National Cancer Center Hospital East, Chiba, Japan Matthew Seymour NIHR Clinical Research Network, Leeds, UK Tim Maughan CRUK/MRC Oxford Institute for Radiation Oncology, Oxford, UK Leonard Saltz Memory Sloan Kettering Cancer Center, New York, NY, USA Eric Van Cutsem Digestive Oncology, University Hospitals Gasthuisberg Leuven and KU Leuven, Leuven, Belgium Alan Venook Department of Medicine, The University of California San Francisco, San Francisco, CA, USA Hans-Joachim Schmoll Klinik fur Innere Med IV, University Clinic Halle, Saale, Germany Richard Goldberg Department of Oncology, West Virginia University, Morgantown, WV, USA Paulo Hoff Centro de Oncologia de Brasilia do Sirio Libanes: Unidade Lago Sul, Siro Libanes, Brazil J. Randolph Hecht Ronald Reagan UCLA Medical Center, UCLS Medical Center, Santa Monica, CA, USA Herbert Hurwitz Duke Cancer Institute, Duke University, Durham, NC, USA Cornelis Punt Department of Medical Oncology, University of Amsterdam, Amsterdam, The Netherlands Eduard Diaz Rubio Department Oncology, Hospital ClĂ­nico San Carlos, Madrid, Spain Miriam Koopman Department of Medical Oncology, University Medical Center Utrecht, University of Utrecht, Utrecht, The Netherlands Chiara Cremolini Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy Volker Heinemann Department of Medical Oncology and Comprehensive Cancer Center, University of Munich, Munich, Germany Christophe Tournigard Hopital Henri Mondor, Creteil, France Carsten Bokemeyer Department of Oncology, Hematology and Bone Marrow Transplantation with Section of Pneumology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany Charles Fuchs Director of Yale Cancer Center, Boston, MA, USA Niall Tebbutt Sydney Medical School, University of Sydney, Sydney, Australia John Souglakos University of Crete, Heraklion, Greece Jean-Yves Doulliard University of Nantes Medical School, Nantes, France Fairooz Kabbinavar UCLA Medical Center, Santa Monica, CA, USA Benoist Chibaudel Department of Medical Oncology, Franco-British Institute, Levallois-Perret, France Aimery de Gramont Department of Medical Oncology, Franco-British Institute, Levallois-Perret, France Qian Shi Department of Health Sciences Research, Mayo Clinic, Rochester, MN, USA Axel Grothey West Cancer Center, Germantown, TN, USA Richard Adams Cardiff University and Velindre Cancer Center, Cardiff, UK Corresponding Author: [email protected] *Co-first authors. https://creativecommons.org/licenses/by-nc/4.0/This article is distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 License (https://creativecommons.org/licenses/by-nc/4.0/) which permits non-commercial use, reproduction and distribution of the work without further permission provided the original work is attributed as specified on the SAGE and Open Access page (https://us.sagepub.com/en-us/nam/open-access-at-sage). Abstract Background: Benchmarking international cancer survival differences is necessary to evaluate and improve healthcare systems. Our aim was to assess the potential regional differences in outcomes among patients with metastatic colorectal cancer (mCRC) participating in international randomized clinical trials (RCTs). Design: Countries were grouped into 11 regions according to the World Health Organization and the EUROCARE model. Meta-analyses based on individual patient data were used to synthesize data across studies and regions and to conduct comparisons for outcomes in a two-stage random-effects model after adjusting for age, sex, performance status, and time period. We used mCRC patients enrolled in the first-line RCTs from the ARCAD database, which provided enrolling country information. There were 21,509 patients in 27 RCTs included across the 11 regions. Results: Main outcomes were overall survival (OS) and progression-free survival (PFS). Compared with other regions, patients from the United Kingdom (UK) and Ireland were proportionaly over-represented, older, with higher performance status, more frequently male, and more commonly not treated with biological therapies. Cohorts from central Europe and the United States (USA) had significantly longer OS compared with those from UK and Ireland (p = 0.0034 and p < 0.001, respectively), with median difference of 3–4 months. The survival deficits in the UK and Ireland cohorts were, at most, 15% at 1 year. No evidence of a regional disparity was observed for PFS. Among those treated without biological therapies, patients from the UK and Ireland had shorter OS than central Europe patients (p < 0.001). Conclusions: Significant international disparities in the OS of cohorts of mCRC patients enrolled in RCTs were found. Survival of mCRC patients included in RCTs was consistently lower in the UK and Ireland regions than in central Europe, southern Europe, and the USA, potentially attributed to greater overall population representation, delayed diagnosis, and reduced availability of therapies

    Health, education, and social care provision after diagnosis of childhood visual disability

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    Aim: To investigate the health, education, and social care provision for children newly diagnosed with visual disability.Method: This was a national prospective study, the British Childhood Visual Impairment and Blindness Study 2 (BCVIS2), ascertaining new diagnoses of visual impairment or severe visual impairment and blindness (SVIBL), or equivalent vi-sion. Data collection was performed by managing clinicians up to 1-year follow-up, and included health and developmental needs, and health, education, and social care provision.Results: BCVIS2 identified 784 children newly diagnosed with visual impairment/SVIBL (313 with visual impairment, 471 with SVIBL). Most children had associated systemic disorders (559 [71%], 167 [54%] with visual impairment, and 392 [84%] with SVIBL). Care from multidisciplinary teams was provided for 549 children (70%). Two-thirds (515) had not received an Education, Health, and Care Plan (EHCP). Fewer children with visual impairment had seen a specialist teacher (SVIBL 35%, visual impairment 28%, χ2p < 0.001), or had an EHCP (11% vs 7%, χ2p < 0 . 01).Interpretation: Families need additional support from managing clinicians to access recommended complex interventions such as the use of multidisciplinary teams and educational support. This need is pressing, as the population of children with visual impairment/SVIBL is expected to grow in size and complexity.This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited
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