24 research outputs found

    The Beaker phenomenon and the genomic transformation of northwest Europe

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    From around 2750 to 2500 bc, Bell Beaker pottery became widespread across western and central Europe, before it disappeared between 2200 and 1800 bc. The forces that propelled its expansion are a matter of long-standing debate, and there is support for both cultural diffusion and migration having a role in this process. Here we present genome-wide data from 400 Neolithic, Copper Age and Bronze Age Europeans, including 226 individuals associated with Beaker-complex artefacts. We detected limited genetic affinity between Beaker-complex-associated individuals from Iberia and central Europe, and thus exclude migration as an important mechanism of spread between these two regions. However, migration had a key role in the further dissemination of the Beaker complex. We document this phenomenon most clearly in Britain, where the spread of the Beaker complex introduced high levels of steppe-related ancestry and was associated with the replacement of approximately 90% of Britain’s gene pool within a few hundred years, continuing the east-to-west expansion that had brought steppe-related ancestry into central and northern Europe over the previous centuries

    Breast cancer management pathways during the COVID-19 pandemic: outcomes from the UK ‘Alert Level 4’ phase of the B-MaP-C study

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    Abstract: Background: The B-MaP-C study aimed to determine alterations to breast cancer (BC) management during the peak transmission period of the UK COVID-19 pandemic and the potential impact of these treatment decisions. Methods: This was a national cohort study of patients with early BC undergoing multidisciplinary team (MDT)-guided treatment recommendations during the pandemic, designated ‘standard’ or ‘COVID-altered’, in the preoperative, operative and post-operative setting. Findings: Of 3776 patients (from 64 UK units) in the study, 2246 (59%) had ‘COVID-altered’ management. ‘Bridging’ endocrine therapy was used (n = 951) where theatre capacity was reduced. There was increasing access to COVID-19 low-risk theatres during the study period (59%). In line with national guidance, immediate breast reconstruction was avoided (n = 299). Where adjuvant chemotherapy was omitted (n = 81), the median benefit was only 3% (IQR 2–9%) using ‘NHS Predict’. There was the rapid adoption of new evidence-based hypofractionated radiotherapy (n = 781, from 46 units). Only 14 patients (1%) tested positive for SARS-CoV-2 during their treatment journey. Conclusions: The majority of ‘COVID-altered’ management decisions were largely in line with pre-COVID evidence-based guidelines, implying that breast cancer survival outcomes are unlikely to be negatively impacted by the pandemic. However, in this study, the potential impact of delays to BC presentation or diagnosis remains unknown

    Pattern-specific contrast threshold elevation

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    The Lie transformation group model of visual perception

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    Geometric psychology generates the visual Gestalt.

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    Global factors generate the mccollough effect

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    It has recently been demonstrated that certain globally orthogonal pattern pairs derived from Hoffman\u27s Lie Transformation Group Model of Neuropsychology (LTG/NP) are sufficient to generate McCollough effects (pattern-contingent colour aftereffects: PCCAES). We now provide evidence that the global factors postulated to generate these particular PCCAEs are also necessary. In Experiment 1 observers made controlled eye movements over the induction patterns and subsequently showed PCCAEs which were as strong as those obtained under central fixation. The induction process therefore did not depend on selectively adapting local oriented and colour-specific edge detectors. The global structure of the inducing patterns appears to be a necessary component of the generation of such aftereffects. In Experiment 2, a number of pattern pairs having various degrees of global organization were used as induction patterns, but in every case there was an equal degree of local orthogonality. Local orthogonality was shown not to be sufficient to induce PCCAEs, but global orthogonality was. These results lend strong support to the notion that McCollough-type PCCAEs are generated in a structure of the visual system somewhat above the level of strictly local operations, whether defined as edge and bar detectors or, equivalently, as units selectively tuned to different spatial frequencies and orientations. The global nature of the effects, and the particular pattern structures involved, lead us to suggest that Hoffman\u27s LTG/NP provides a sound basis for explaining our findings
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