31 research outputs found

    Self-similar voiding solutions of a single layered model of folding rocks

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    In this paper we derive an obstacle problem with a free boundary to describe the formation of voids at areas of intense geological folding. An elastic layer is forced by overburden pressure against a V-shaped rigid obstacle. Energy minimization leads to representation as a nonlinear fourth-order ordinary differential equation, for which we prove their exists a unique solution. Drawing parallels with the Kuhn-Tucker theory, virtual work, and ideas of duality, we highlight the physical significance of this differential equation. Finally we show this equation scales to a single parametric group, revealing a scaling law connecting the size of the void with the pressure/stiffness ratio. This paper is seen as the first step towards a full multilayered model with the possibility of voiding

    Costs of Early Invasive Breast Cancer in England Using National Patient-Level Data.

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    OBJECTIVES: This study aimed to use patient-level data to provide up-to-date estimates of early invasive breast cancer care costs by stage in England and to explore to what extent these costs varied based on patients' ages and geographic regions. METHODS: This study identified women aged 50 years and older who had been diagnosed with early invasive breast cancer between January 1, 2014, and December 31, 2015, using linked cancer registrations and routine hospital data sets generated from the usual care for all National Health Service trusts in England. Cost estimates were derived from hospital records in Hospital Episodes Statistics with additional chemotherapy and radiotherapy information from the national data sets. We fitted general linear regression models to analyze the cost data. The model that best fit the data was selected using the model selection criteria of Akaike information criterion. RESULTS: 55 662 women with early invasive breast cancer in England were included. The generalized linear model with log-gamma distribution fit the data best. The costs of breast cancer care for 1 year after diagnosis were strongly dependent on stage at diagnosis, controlling for other covariates. The estimated average per-patient hospital-related costs were £5167 at stage I, £7613 at stage II, and £13 330 at stage IIIA. Costs decreased with increasing age (P < .001) and varied across region (P < .001), deprivation level (P < .001), referral source (P < .01), presence of comorbidities (P< .001), and tumor receptor (ER/PR/HER2) status (P < .001). CONCLUSIONS: In England, the costs of breast cancer care increased with advancing stage of the disease at diagnosis. Breast cancer costs varied by age and geographic region

    A game prototype for understanding the safety issues of a lifeboat launch

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    © 2018 The Author(s) Novel, advanced game techniques provide us with new possibilities to mimic a complicated training process, with the added benefit of enhanced safety. In this paper, we design and implement a 3D game with the support of virtual reality equipment which imitates the process of a lifeboat launch, involving both tractor manoeuvres and boat operations. It is a complex but vital process which can save lives at sea but also has many potential hazards. The primary objective of the game is to allow novices to better understand the sequence of the operations and manage the potential risks which may occur during the launch process. Additionally, the game has been promoted to the general public for educational purposes and to raise awareness of the safety issues involved. The key modules of the game are designed based on physical simulations to give the players enhanced plausible cognition and enjoyable interaction. We conducted two case studies for the two purposes of the games: one for training with volunteers without launching experience and the other for public awareness of the potential hazards with young children. The game is proven to be very promising for future professional training, and it serves the educational purpose of awareness of the safety issues for general public while being entertaining

    Risk factors for the development of invasive cancer in unresected ductal carcinoma in situ.

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    BACKGROUND: The natural history of ductal carcinoma in situ (DCIS) remains uncertain. The risk factors for the development of invasive cancer in unresected DCIS are unclear. METHODS: Women diagnosed with DCIS on needle biopsy after 1997 who did not undergo surgical resection for ≥1 year after diagnosis were identified by breast centres and the cancer registry and outcomes were reviewed. RESULTS: Eighty-nine women with DCIS diagnosed 1998-2010 were identified. The median age at diagnosis was 75 (range 44-94) years with median follow-up (diagnosis to death, invasive disease or last review) of 59 (12-180) months. Twenty-nine women (33%) developed invasive breast cancer after a median interval of 45 (12-144) months. 14/29 (48%) with high grade, 10/31 (32%) with intermediate grade and 3/17 (18%) with low grade DCIS developed invasive cancer after median intervals of 38, 60 and 51 months. The cumulative incidence of invasion was significantly higher in high grade DCIS than other grades (p = .0016, log-rank test). Invasion was more frequent in lesions with calcification as the predominant feature (23/50 v. 5/25; p = .042) and in younger women (p = .0002). Endocrine therapy was associated with a lower rate of invasive breast cancer (p = .048). CONCLUSIONS: High cytonuclear grade, mammographic microcalcification, young age and lack of endocrine therapy were risk factors for DCIS progression to invasive cancer. Surgical excision of high grade DCIS remains the treatment of choice. Given the uncertain long-term natural history of non-high grade DCIS, the option of active surveillance of women with this condition should be offered within a clinical trial

    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

    The Anglo-Saxon migration and the formation of the early English gene pool.

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    The history of the British Isles and Ireland is characterized by multiple periods of major cultural change, including the influential transformation after the end of Roman rule, which precipitated shifts in language, settlement patterns and material culture1. The extent to which migration from continental Europe mediated these transitions is a matter of long-standing debate2-4. Here we study genome-wide ancient DNA from 460 medieval northwestern Europeans-including 278 individuals from England-alongside archaeological data, to infer contemporary population dynamics. We identify a substantial increase of continental northern European ancestry in early medieval England, which is closely related to the early medieval and present-day inhabitants of Germany and Denmark, implying large-scale substantial migration across the North Sea into Britain during the Early Middle Ages. As a result, the individuals who we analysed from eastern England derived up to 76% of their ancestry from the continental North Sea zone, albeit with substantial regional variation and heterogeneity within sites. We show that women with immigrant ancestry were more often furnished with grave goods than women with local ancestry, whereas men with weapons were as likely not to be of immigrant ancestry. A comparison with present-day Britain indicates that subsequent demographic events reduced the fraction of continental northern European ancestry while introducing further ancestry components into the English gene pool, including substantial southwestern European ancestry most closely related to that seen in Iron Age France5,6

    The Anglo-Saxon migration and the formation of the early English gene pool

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    The history of the British Isles and Ireland is characterized by multiple periods of major cultural change, including the influential transformation after the end of Roman rule, which precipitated shifts in language, settlement patterns and material culture1. The extent to which migration from continental Europe mediated these transitions is a matter of long-standing debate2,3,4. Here we study genome-wide ancient DNA from 460 medieval northwestern Europeans—including 278 individuals from England—alongside archaeological data, to infer contemporary population dynamics. We identify a substantial increase of continental northern European ancestry in early medieval England, which is closely related to the early medieval and present-day inhabitants of Germany and Denmark, implying large-scale substantial migration across the North Sea into Britain during the Early Middle Ages. As a result, the individuals who we analysed from eastern England derived up to 76% of their ancestry from the continental North Sea zone, albeit with substantial regional variation and heterogeneity within sites. We show that women with immigrant ancestry were more often furnished with grave goods than women with local ancestry, whereas men with weapons were as likely not to be of immigrant ancestry. A comparison with present-day Britain indicates that subsequent demographic events reduced the fraction of continental northern European ancestry while introducing further ancestry components into the English gene pool, including substantial southwestern European ancestry most closely related to that seen in Iron Age France5,6

    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
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