631 research outputs found

    Not Always Black and White: Colour Aberrations in the Dovekie

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    We describe four records of colour aberrations in the dovekie (Alle alle). During six years of studies of breeding ecology in two large dovekie colonies in West Spitsbergen, we recorded one albino chick (white feathers, red eyes, pinkish legs and feet), one adult or subadult with a “brown” aberration (all black parts turned dark brown), one adult in a typical summer plumage with depigmented (pinkish) legs and feet, and one chick in a typical plumage, but with whitish feathers on back and wing coverts. Albinism and “brown” mutations are heritable traits. The two remaining colour aberrations probably have been acquired and might have been caused by disease, malnutrition, or other unknown factors.Nous décrivons quatre mentions d’aberrations de couleur chez le mergule nain (Alle alle). Au cours de six années d’étude en écologie des oiseaux nicheurs au sein de deux grandes colonies de mergules nains de Spitzberg Ouest, nous avons dénoté un oisillon albinos (ailes blanches, yeux rouges, pattes et pieds rosés), un adulte ou jeune adulte doté d’une aberration « brune » (toutes les parties noires étaient devenues brunes), un adulte au plumage d’été typique et avec pattes et pieds dépigmentés (rosés) et un oisillon avec plumage typique, mais doté de plumes blanchâtres sur le dos et la couverture alaire. L’albinisme et les mutations « brunes » sont des caractères héréditaires, tandis que les deux autres aberrations de couleur ont probablement été acquises et peuvent être le résultat de maladie, de malnutrition ou d’autres facteurs inconnus

    Glaucous Gull Predation on Dovekies: Three New Hunting Methods

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    We describe three previously unreported methods that hunting glaucous gulls (Larus hyperboreus) use to capture nesting and fledgling dovekies (Alle alle). During the nesting period, the pale-gray and white gulls camouflaged themselves by perching with head lowered on remnant snow patches in the dovekie colony, trying to ambush flying adults. We observed two other glaucous gull hunting methods on the open fjord water after the dovekie fledglings had left the colony. Gulls approached young dovekies in a fast, low-level glide, presumably to surprise the prey, and attempted to snatch them from the water. Gulls also swam rapidly towards young dovekies, zigzagging among small ice floes, presumably to confuse the birds and catch them before they could dive. The methods described, representing technical foraging innovations, supplement the evidence that gulls are a bird family that displays a diverse foraging innovation repertoire.Nous décrivons trois méthodes jamais signalées auparavant auxquelles recourent les goélands bourgmestres (Larus hyperboreus) pour capturer les mergules nains (Alle alle) aux stades de la nidification et de l’envol. Pendant la période de nidification, les goélands gris clair et blancs se camouflagent en se rabaissant la tête dans les restes de bancs de neige au sein des colonies de mergules nains afin d’essayer de piéger les adultes capables de voler. Nous avons observé deux autres méthodes de chasse de la part des goélands bourgmestres sur les eaux libres du fjord une fois que les mergules nains prêts à l’envol ont quitté la colonie. Les goélands s’approchaient des jeunes mergules nains en glissant rapidement et à faible altitude, vraisemblablement pour surprendre leurs proies, et essayaient de les arracher de l’eau. Les goélands se mettaient aussi à nager rapidement vers les jeunes mergules nains, en zigzaguant entre les bancs de glace flottante, probablement pour mélanger les oiseaux et pour les attraper avant qu’ils n’aient le temps de plonger. Les méthodes ainsi décrites, qui représentent des innovations techniques de chasse, s’ajoutent aux preuves qui attestent du fait que les goélands constituent une famille d’oiseaux dotée d’un répertoire de chasse innovateur et varié

    Wrought Constituent

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    Duration of female parental care and their survival in the little auk Alle alle - are these two traits linked?

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    Desertion of offspring before its independence by one of the parents is observed in a number of avian species with bi-parental care but reasons for this strategy are not fully understood. This behaviour is particularly intriguing in species where bi-parental care is crucial to raise the brood successfully. Here, we focus on the little auk, Alle alle, a small seabird with intensive bi-parental care, where the female deserts the brood at the end of the chick rearing period. The little auk example is interesting as most hypotheses to explain desertion of the brood by females (e.g. “re-mating hypothesis”, “body condition hypothesis”) have been rejected for this species. Here, we analysed a possible relationship between the duration of female parental care over the chick and her chances to survive to the next breeding season. We performed the study in two breeding colonies on Spitsbergen with different foraging conditions – more favourable in Hornsund and less favourable in Magdalenefjorden. We predicted that in Hornsund females would stay for shorter periods of time with the brood and would have higher survival rates in comparison with birds from Magdalenefjorden. We found that indeed in less favourable conditions of Magdalenefjorden, females stay longer with the brood than in the more favourable conditions of Hornsund. Moreover, female survival was negatively affected by the length of stay in the brood. Nevertheless, duration of female parental care over the chick was not related to their parental efforts, earlier in the chick rearing period, and survival of males and females was similar. Thus, although females brood desertion and winter survival are linked, the relationship is not straightforward

    “Being woman is to be a woman”: the stigma of „disabled gender” in experience of women with moderate to severe intellectual disability, attending an environmental self-care institution

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    This article presents selected fragments of an analysis within a wider research project conducted for an unpublished master’s thesis, related to the question of gender identity of seven women with moderate to severe intellectual disability, attending an environmental self-care house. Selected fragments of conducted interviews exposed participants’ individual perceptions of femininity. Those results were then connected to a chosen conception of emancipation.This article presents selected fragments of an analysis within a wider research project conducted for an unpublished master’s thesis, related to the question of gender identity of seven women with moderate to severe intellectual disability, attending an environmental self-care house. Selected fragments of conducted interviews exposed participants’ individual perceptions of femininity. Those results were then connected to a chosen conception of emancipation

    Monoclonal antibodies in the treatment of acute lymphoblastic leukemias

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    Several monoclonal antibody-based agents have potential application in the treatment of acute lymphoblastic leukemia (ALL) and bring the promise of increased response rates without excessive toxicity. These include unconjugated monoclonal antibodies, monoclonal antibodies or fragments linked to cytotoxic agents or conjugated to toxins (immunotoxins), bispecific single-chain antibodies that redirect cytotoxic T lymphocytes (via CD3 expression) to surface ALL antigens (eg. CD19) and bispecific T-cell engagers.Monoclonal antibody-based reagents react with blasts by direct and/or indirect mechanisms. Binding by unconjugated monoclonal antibodies directly induce cytotoxicity through inhibition of proliferation or triggering of cell death pathways. Indirect killing may occur via antibody-dependent cell-mediated cytotoxicity and/or complement-dependent cytotoxicity. The cytotoxicity of monoclonal antibodies can increase by linkage to chemotherapy agents and bacterial toxins therefore they do not require active immune response mechanisms for activity and can be effective even in profoundly immunocompromised patients.Herein, we will review the results and status of investigational monoclonal antibody-based therapies in ALL

    The low-temperature phase of morpholinium tetra­fluoro­borate

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    The crystal structure of the low-temperature form of the title compound, C4H10NO+·BF4 −, was determined at 80 K. Two reversible phase transitions, at 158/158 and 124/126 K (heating/cooling), were detected by differential scanning calorimetry for this compound, and the sequence of phase transitions was subsequently confirmed by single-crystal X-ray diffraction experiments. The asymmetric unit at 80 K consists of three BF4 − tetra­hedral anions and three morpholinium cations (Z′ = 3). Hydrogen-bonded morpholinium cations form chains along the [100] direction. The BF4 − anions are connected to these chains by N—H⋯F hydrogen bonds. In the crystal structure, two different layers perpendicular to the [001] direction can be distinguished, which differ in the geometry of the hydrogen bonds between cationic and anionic species
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