743 research outputs found

    An evaluation of the "outertype" keyboard

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    Stability from Structure: Metabolic Networks Are Unlike Other Biological Networks

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    In recent work, attempts have been made to link the structure of biochemical networks to their complex dynamics. It was shown that structurally stable network motifs are enriched in such networks. In this work, we investigate to what extent these findings apply to metabolic networks. To this end, we extend a previously proposed method by changing the null model for determining motif enrichment, by using interaction types directly obtained from structural interaction matrices, by generating a distribution of partial derivatives of reaction rates and by simulating enzymatic regulation on metabolic networks. Our findings suggest that the conclusions drawn in previous work cannot be extended to metabolic networks, that is, structurally stable network motifs are not enriched in metabolic networks

    Local ecosystem feedbacks and critical transitions in the climate

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    Global and regional climate models, such as those used in IPCC assessments, are the best tools available for climate predictions. Such models typically account for large-scale land-atmosphere feedbacks. However, these models omit local vegetationenvironment 5 feedbacks that are crucial for critical transitions in ecosystems. Here, we reveal the hypothesis that, if the balance of feedbacks is positive at all scales, local vegetation-environment feedbacks may trigger a cascade of amplifying effects, propagating from local to large scale, possibly leading to critical transitions in the largescale climate. We call for linking local ecosystem feedbacks with large-scale land10 atmosphere feedbacks in global and regional climate models in order to yield climate predictions that we are more confident about

    How caring work of older women gets disappeared: the gendered dynamics of changing everyday occupations in an older German couple

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    Background: In older couples, everyday occupations need to be adjusted when one of the partners experiences a health decline. Gender dynamics will play a role in this process, yet there is little understanding about how gender can influence and shape changes in couples’ occupations. Aim: To understand the changing occupations of old, independent-living couples when becoming caregivers and care receivers, through a gender lens. Methods: A narrative-in-action methodology with a case-study design has been chosen to enable an in-depth analysis of one couple. Besides joint and individual interviews with both partners, observations were made of their everyday occupations. The analytic process was interpretative, using gender theory as a lens for understanding. Results: In the couple’s narrative there was a difference in the time spent on, and meaning given to, occupations performed by each partner to sustain everyday life. The wife was heavily enrolled in taking care of her husband, a gendered pattern that was rooted in their spousal history. While her efforts were taken-for-granted, his efforts were acknowledged as special. Conclusion: The adjustment of the everyday occupations of this older couple were gendered, and led to a disappearing of the woman’s occupations and the care she was giving. Prevention, Population and Disease management (PrePoD)Geriatrics in primary carePublic Health and primary car

    The Clumping Transition in Niche Competition: a Robust Critical Phenomenon

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    We show analytically and numerically that the appearance of lumps and gaps in the distribution of n competing species along a niche axis is a robust phenomenon whenever the finiteness of the niche space is taken into account. In this case depending if the niche width of the species σ\sigma is above or below a threshold σc\sigma_c, which for large n coincides with 2/n, there are two different regimes. For σ>sigmac\sigma > sigma_c the lumpy pattern emerges directly from the dominant eigenvector of the competition matrix because its corresponding eigenvalue becomes negative. For σ</sigmac\sigma </- sigma_c the lumpy pattern disappears. Furthermore, this clumping transition exhibits critical slowing down as σ\sigma is approached from above. We also find that the number of lumps of species vs. σ\sigma displays a stair-step structure. The positions of these steps are distributed according to a power-law. It is thus straightforward to predict the number of groups that can be packed along a niche axis and it coincides with field measurements for a wide range of the model parameters.Comment: 16 pages, 7 figures; http://iopscience.iop.org/1742-5468/2010/05/P0500

    Predictors of undergoing multivisceral resection, margin status and survival in Dutch patients with locally advanced colorectal cancer

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    Background: The aim of this nationwide observational study was to evaluate factors associated with multivisceral resection (MVR), margin status and overall survival in locally advanced colorectal cancer (CRC). Material and methods: Patients with (y)pT4, cM0 CRC between 2006 and 2017 were selected from the Netherlands Cancer Registry. Cox-proportional hazards modelling was used for survival analysis, stratified for T4a and T4b. Annual hospital volume cut-off was 75 for colon and 40 for rectal resections. Results: A total of 11.930 patients were included and 2410 patients (20.2%) underwent MVR. Factors associated with MVR for colon and rectal cancer besides cT4 category were more recent diagnosis (OR 3.61, CI 95% 3.06–4.25 (colon) and OR 2.72, CI 95% 1.82–4.08 (rectum)) and high hospital volume (OR 1.20, CI 95% 1.05–1.38 (colon) and OR 2.17, CI 95% 1.55–3.04 (rectum)). Patients ≥70 year were less likely to undergo MVR for colon cancer (OR 0.80, 95% CI 0.70–0.90). Risk factors for incomplete resection were cT4 (OR 3.08, CI 95% 2.35–4.04 (colon) and OR 1.82, CI 95% 1.13–2.94 (rectum)) and poor/undifferentiated tumors (OR 1.41, CI 95% 1.14–1.72 (colon) and OR 1.69, CI 95% 1.05–2.74 (rectum)). More recent diagnosis was independently associated with less incomplete resections in colon cancer (OR 0.58, CI 95% 0.40–0.76). Independent predictors of survival were age, resection margin, nodal status and adjuvant chemotherapy, but not MVR. Conclusion: Treatment of locally advanced CRC with MVR at population level was influenced by year of diagnosis and hospital volume. Margin status in colon cancer improved substantially over time.</p

    Predictors of undergoing multivisceral resection, margin status and survival in Dutch patients with locally advanced colorectal cancer

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    Background: The aim of this nationwide observational study was to evaluate factors associated with multivisceral resection (MVR), margin status and overall survival in locally advanced colorectal cancer (CRC). Material and methods: Patients with (y)pT4, cM0 CRC between 2006 and 2017 were selected from the Netherlands Cancer Registry. Cox-proportional hazards modelling was used for survival analysis, stratified for T4a and T4b. Annual hospital volume cut-off was 75 for colon and 40 for rectal resections. Results: A total of 11.930 patients were included and 2410 patients (20.2%) underwent MVR. Factors associated with MVR for colon and rectal cancer besides cT4 category were more recent diagnosis (OR 3.61, CI 95% 3.06–4.25 (colon) and OR 2.72, CI 95% 1.82–4.08 (rectum)) and high hospital volume (OR 1.20, CI 95% 1.05–1.38 (colon) and OR 2.17, CI 95% 1.55–3.04 (rectum)). Patients ≥70 year were less likely to undergo MVR for colon cancer (OR 0.80, 95% CI 0.70–0.90). Risk factors for incomplete resection were cT4 (OR 3.08, CI 95% 2.35–4.04 (colon) and OR 1.82, CI 95% 1.13–2.94 (rectum)) and poor/undifferentiated tumors (OR 1.41, CI 95% 1.14–1.72 (colon) and OR 1.69, CI 95% 1.05–2.74 (rectum)). More recent diagnosis was independently associated with less incomplete resections in colon cancer (OR 0.58, CI 95% 0.40–0.76). Independent predictors of survival were age, resection margin, nodal status and adjuvant chemotherapy, but not MVR. Conclusion: Treatment of locally advanced CRC with MVR at population level was influenced by year of diagnosis and hospital volume. Margin status in colon cancer improved substantially over time.</p
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