286 research outputs found

    Encountering competitors reduces clutch size and increases offspring size in a parasitoid with female–female fighting

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    Understanding the size of clutches produced by only one parent may require a game-theoretic approach: clutch size may affect offspring fitness in terms of future competitive ability. If larger clutches generate smaller offspring and larger adults are more successful in acquiring and retaining resources, clutch size optima should be reduced when the probability of future competitive encounters is higher. We test this using Goniozus nephantidis, a gregarious parasitoid wasp in which the assumption of size-dependent resource acquisition is met via female–female contests for hosts. As predicted, smaller clutches are produced by mothers experiencing competition, due to fewer eggs being matured and to a reduced proportion of matured eggs being laid. As assumed, smaller clutches generate fewer but larger offspring. We believe this is the first direct evidence for pre-ovipositional and game-theoretic clutch size adjustment in response to an intergenerational fitness effect when clutches are produced by a single individual

    Heavy Neutrino searches through Double-Bang Events at Super-Kamiokande, DUNE, and Hyper-Kamiokande

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    A variety of new physics scenarios allow for neutrinos to up-scatter into a heavy neutral lepton state. For a range of couplings and neutrino energies, the heavy neutrino may travel some distance before decaying to visible final states. When both the up-scattering and decay occur within the detector volume, these "double bang" events produce distinctive phenomenology with very low background. In this work, we first consider the current sensitivity at Super-Kamiokande via the atmospheric neutrino flux, and find current data may already provide new constraints. We then examine projected future sensitivity at DUNE and Hyper-Kamiokande, including both atmospheric and beam flux contributions to double-bang signals.Comment: 17 pages, 6 figures. v2: minor changes, references added and typos fixed. Matches version accepted for publication in JHE

    Multiple Mechanisms Regulate NuMA Dynamics at Spindle Poles

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    The large coiled-coil protein NuMA plays an essential role in organizing microtubule minus ends at spindle poles in vertebrate cells. Here, we use both in vivo and in vitro methods to examine NuMA dynamics at mitotic spindle poles. Using fluorescence recovery after photobleaching, we show that an exogenously expressed green-fluorescent-protein/NuMA fusion undergoes continuous exchange between soluble and spindle-associated pools in living cells. These dynamics require cellular energy and display an average half-time for fluorescence recovery of approximately 3 minutes. To explore how NuMA dynamics at spindle poles is regulated, we exploited the association of NuMA with microtubule asters formed in mammalian mitotic extracts. Using a monoclonal antibody specific for human NuMA, we followed the fate of human NuMA associated with microtubule asters upon dilution with a hamster mitotic extract. Consistent with in vivo data, this assay shows that NuMA can be displaced from the core of pre-assembled asters into the soluble pool. The half-time of NuMA displacement from asters under these conditions is approximately 5 minutes. Using this assay, we show that protein kinase activity and the NuMA-binding protein LGN regulate the dynamic exchange of NuMA on microtubule asters. Thus, the dynamic properties of NuMA are regulated by multiple mechanisms including protein phosphorylation and binding to the LGN protein, and the rate of exchange between soluble and microtubule-associated pools suggests that NuMA associates with an insoluble matrix at spindle poles

    Practitioners' use of motivational interviewing in sport: A qualitative enquiry

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    This study explored the use of motivational interviewing (MI) in sport contexts by experts in that approach. Specifically, the purpose was to understand which aspects of the MI approach are deemed valuable for working in sport and to begin to understand how these aspects are best applied. Nine practitioners participated in semistructured interviews, and thematic analysis identified themes related to core and subcomponents of MI (e.g., relational spirit, technical microskills, applied tools, and the MI communication styles continuum). Additional themes relate to integrating MI with other interventions, the challenges of working with athletes (e.g., mandated attendance, ambivalence about change), and unique aspects of working in sport contexts (e.g., frequency, duration, and location of contact points). The participants also outlined essential ingredients for an MI training curriculum for practitioners in sport. This counseling approach appears to have valuable relational and technical components to facilitate the building of the therapeutic alliance, enhance athlete readiness for change, and support delivery of action-oriented interventions in applied sport psychology
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