727 research outputs found

    Adaptive and non-adaptive divergence in a common landscape

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    Species in a common landscape often face similar selective environments. The capacity of organisms to adapt to these environments may be largely species specific. Quantifying shared and unique adaptive responses across species within landscapes may thus improve our understanding of landscape-moderated biodiversity patterns. Here we test to what extent populations of two coexisting and phylogenetically related fishes—three-spined and nine-spined stickleback—differ in the strength and nature of neutral and adaptive divergence along a salinity gradient. Phenotypic differentiation, neutral genetic differentiation and genomic signatures of adaptation are stronger in the three-spined stickleback. Yet, both species show substantial phenotypic parallelism. In contrast, genomic signatures of adaptation involve different genomic regions, and are thus non-parallel. The relative contribution of spatial and environmental drivers of population divergence in each species reflects different strategies for persistence in the same landscape. These results provide insight in the mechanisms underlying variation in evolutionary versatility and ecological success among species within landscapes

    Quasiparticle properties in a density functional framework

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    We propose a framework to construct the ground-state energy and density matrix of an N-electron system by solving selfconsistently a set of single-particle equations. The method can be viewed as a non-trivial extension of the Kohn-Sham scheme (which is embedded as a special case). It is based on separating the Green's function into a quasi-particle part and a background part, and expressing only the background part as a functional of the density matrix. The calculated single-particle energies and wave functions have a clear physical interpretation as quasiparticle energies and orbitals.Comment: 12 pages, 1 figure, to be published in Phys. Rev.

    PCN1 COST ANALYSIS OF HLA-IDENTICAL SIBLING AND VOLUNTARY UNRELATED ALLOGENEIC BONE MARROW AND PERIPHERAL BLOOD STEM CELL TRANSPLANTATION IN ADULTS WITH ACUTE MYELOCYTIC LEUKAEMIA OR ACUTE LYMPHOBLASTIC LEUKAEMIA

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    Item does not contain fulltextAllogeneic stem cell transplantation (SCT) is one of the most expensive medical procedures. However, only a few studies to date have addressed the costs of HLA-identical sibling transplantation and only one study has reported costs of unrelated transplantation. No recent cost analysis with a proper follow-up period and donor identification expenses is available on related or voluntary matched unrelated donor (MUD) SCT for adult AML or ALL. Therefore, we calculated direct medical (hospital) costs based on 97 adults who underwent HLA-identical sibling bone marrow transplantation (BMT) or peripheral blood stem cell transplantation (PBSCT), and patients who received a graft from a MUD between 1994 and 1999. The average costs per transplanted patient were Euro 98,334 (BMT), Euro 151,754 (MUD), and Euro 98,977 (PBSCT), including donor identification expenses, 2 years follow-up and costs of patients who were not transplanted after they had been planned to receive an allograft. The majority of these costs was generated during the hospitalisation for graft infusion. For MUD transplants, nearly one-third of these costs was spent on the search for a suitable donor. For patients who were alive after 2 years, cumulative expenses were calculated to be Euro 103,509 (BMT), Euro 173,587 (MUD), and Euro 105,906 (PBSCT)

    Occupational therapists’ views of using a virtual reality interior design application within the pre-discharge home visit process

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    This article has been made available through the Brunel Open Access Publishing Fund.Background: A key role of Occupational Therapists (OTs) is to carry out pre-discharge home visits (PHV) and propose appropriate adaptations to the home environment, to enable patients to function independently after hospital-home discharge. However, research shows that more than 50% of specialist equipment installed as part of home adaptations is not used by patients. A key reason for this is that decisions about home adaptations are often made without adequate collaboration and consultation with the patient. Consequently, there is an urgent need to seek out new and innovative uses of technology to facilitate patient/practitioner collaboration, engagement and shared decision making in the PHV process. Virtual reality interior design applications (VRIDAs) primarily allow users to simulate the home environment and visualise changes prior to implementing them. Customised VRIDAs, which also model specialist occupational therapy equipment, could become a valuable tool to facilitate improved patient/practitioner collaboration if developed effectively and integrated into the PHV process. Objective: To explore the perceptions of occupational therapists with regards to using VRIDAs as an assistive tool within the PHV process. Methods: Task-oriented interactive usability sessions, utilising the think-aloud protocol and subsequent semi-structured interviews were carried out with seven Occupational Therapists who possessed significant experience across a range of clinical settings. Template analysis was carried out on the think-aloud and interview data. Analysis was both inductive and driven by theory, centring around the parameters that impact upon the acceptance, adoption and use of this technology in practice as indicated by the Technology Acceptance Model (TAM). Results: OTs’ perceptions were identified relating to three core themes: (1) perceived usefulness (PU), (2) perceived ease of use (PEoU), and (3) actual use (AU). Regarding PU, OTs believed VRIDAs had promising potential to increase understanding, enrich communications and patient involvement, and improved patient/practitioner shared understanding. However, it was unlikely that VRIDAs would be suitable for use with cognitively impaired patients. For PEoU, all OTs were able to use the software and complete the tasks successfully, however, participants noted numerous specialist equipment items that could be added to the furniture library. AU perceptions were positive regarding use of the application across a range of clinical settings including children/young adults, long-term conditions, neurology, older adults, and social services. However, some “fine tuning” may be necessary if the application is to be optimally used in practice. Conclusions: Participants perceived the use of VRIDAs in practice would enhance levels of patient/practitioner collaboration and provide a much needed mechanism via which patients are empowered to become more equal partners in decisions made about their care. Further research is needed to explore patient perceptions of VRIDAs, to make necessary customisations accordingly, and to explore deployment of the application in a collaborative patient/practitioner-based context

    Prevention of Epstein-Barr virus-lymphoproliferative disease by molecular monitoring and preemptive rituximab in high-risk patients after allogeneic stem cell transplantation

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    Recipients of a partially T-cell-depleted (TCD) allogeneic stem cell transplantation (allo-SCT) developing reactivation of Epstein-Barr virus (EBV) with quantified viral DNA levels exceeding 1000 genome equivalents/milliliter (geq/mL) are at high risk for EBV-lymphoproliferative disease (EBV-LPD). We studied whether preemptive therapy with rituximab prevents EBV-LPD, LPD-mo

    The impact of the COVID-19 pandemic on health-related quality of life in head and neck cancer survivors:An observational cohort studs

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    Objective: To investigate the impact of the COVID-19 pandemic on physical, psychological, and social aspects of health-related quality of life (HRQOL) among head and neck cancer (HNC) survivors. Materials and methods: Prospectively collected data from the NETherlands QUality of life and BIomedical Cohort study in HNC were used. All patients were diagnosed and treated before the COVID-19 pandemic. Patient reported outcome measures (PROMs) collected 24 and 36 months after treatment (M24 and M36) were compared between survivors who completed both assessments before the COVID-19 pandemic and those who completed M24 before but M36 during the pandemic. Personal, clinical, physical, psychological, social, and lifestyle characteristics of the survivors assessed at baseline or M24 were investigated as potential effect modifiers. Results: In total, 318 HNC survivors were included, of which 199 completed both M24 and M36 before the COVID-19 pandemic and 119 completed M24 before but M36 during the pandemic. Changes in HRQOL between 24 and 36 months follow-up did not differ between the two groups for any of the PROMs. Nevertheless, in some subgroups of HNC survivors the COVID-19 pandemic negatively affected the course of HRQOL for several PROMs while it positively affected the course of HRQOL for other PROMs. Conclusions: The COVID-19 pandemic did not affect HRQOL in HNC survivors in general, but some subgroups were affected in a positive and others in a negative way.</p
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