Travelling waves and heteroclinic networks in models of spatially-extended cyclic competition

Dynamical systems containing heteroclinic cycles and networks can be invoked as models of intransitive competition between three or more species. When populations are assumed to be well-mixed, a system of ordinary differential equations (ODEs) describes the interaction model. Spatially extending these equations with diffusion terms creates a system of partial differential equations which captures both the spatial distribution and mobility of species. In one spatial dimension, travelling wave solutions can be observed, which correspond to periodic orbits in ODEs that describe the system in a steady-state travelling frame of reference. These new ODEs also contain a heteroclinic structure. For three species in cyclic competition, the topology of the heteroclinic cycle in the well-mixed model is preserved in the steady-state travelling frame of reference. We demonstrate that with four species, the heteroclinic cycle which exists in the well-mixed system becomes a heteroclinic network in the travelling frame of reference, with additional heteroclinic orbits connecting equilibria not connected in the original cycle. We find new types of travelling waves which are created in symmetry-breaking bifurcations and destroyed in an orbit flip bifurcation with a cycle between only two species. These new cycles explain the existence of "defensive alliances" observed in previous numerical experiments. We further describe the structure of the heteroclitic network for any number of species, and we conjecture how these results may generalise to systems of any arbitrary number of species in cyclic competition

Vegetatie en opslibbing in de Peazemerlannen en het referentiegebied west - Groningen : Evaluatie 2007 - 2012

Deze rapportage beschrijft de monitoring in het kader van de bodemdaling onder de kwelder de Peazemerlannen. Er wordt een overzicht gegeven van de activiteiten en meetresultaten in de kwelder en zomerpolder van de Peazemerlannen en het referentiegebied in de kwelderwerken in West-Groningen van de jaren 2007 t/m 2012. De meeste gegevens worden weergegeven vanaf 2007, het startjaar van de gaswinning. Oudere data worden, waar nuttig, ook weergegeven of er wordt verwezen naar eerdere rapporten

MUC5B levels in submandibular gland saliva of patients treated with radiotherapy for head-and-neck cancer: A pilot study

<p>Abstract</p> <p>Background</p> <p>The salivary mucin MUC5B, present in (sero)mucous secretions including submandibular gland (SMG) saliva, plays an important role in the lubrication of the oral mucosa and is thought to be related to the feeling of dry mouth. We investigated if MUC5B levels in SMG saliva could distinguish between the presence or absence of severe dry mouth complaints 12 months after radiotherapy (RT) for head-and-neck cancer (HNC).</p> <p>Findings</p> <p>Twenty-nine HNC patients with a residual stimulated SMG secretion rate of ≥0.2 ml/10 min at 12 months after RT were analyzed. MUC5B (in U; normalized to 1) and total protein levels (mg/ml) were measured in SMG saliva at baseline and 12 months after RT using ELISA and BCA protein assay, respectively. Overall, median MUC5B levels decreased after RT from 0.12 to 0.03 U (<it>p</it> = 0.47). Patients were dichotomized into none/mild xerostomia (n = 12) and severe xerostomia (n = 17) based on a questionnaire completed at 12 months. SMG and whole saliva flow rates decreased after RT but were comparable in both groups. The median MUC5B level was higher in patients with no or mild xerostomia compared to patients with severe xerostomia (0.14 vs 0.01 U, <it>p</it> = 0.22). Half of the patients with severe xerostomia had no detectable MUC5B at 12 months after RT. No differences in total protein levels were observed.</p> <p>Conclusions</p> <p>Qualitative saliva parameters like MUC5B need further investigation in RT-induced xerostomia. This pilot study showed a trend towards lower MUC5B levels in the SMG saliva of patients with severe xerostomia 12 months after RT for HNC.</p

Excessive toxicity of cabozantinib in a phase II study in patients with recurrent and/or metastatic salivary gland cancer

AIM: Because the tyrosine kinases c-MET and vascular endothelial growth factor receptors (VEGFR) are often overexpressed in salivary gland cancer (SGC), this study evaluated the efficacy and safety of cabozantinib in patients with recurrent/metastatic (R/M) SGC. PATIENTS AND METHODS: A single-centre phase II study was conducted. Patients with immunohistochemical c-MET-positive R/M SGC were included in three cohorts: adenoid cystic carcinoma (ACC); salivary duct carcinoma (SDC) and other miscellaneous SGCs. No prior systemic treatments were required. Patients started cabozantinib 60 mg once daily. The primary outcome was the objective response rate (ORR). Secondary outcomes included survival, safety and quality of life. Per Simon-two-stage design, depending on efficacy, a maximum of 43 patients would be included. RESULTS: In total, 25 patients were included until premature closure owing to severe toxicity. Six patients (24%) had grade 3-5 wound complications, occurring at a median of 7.1 months on cabozantinib treatment (range 2.1-12.6). Remarkably, four of these six patients developed this complication in the area prior exposed to high-dose radiotherapy. Other grade ≥3 adverse events in >1 patient were hypertension (20%), diarrhoea (8%) and dehydration (8%). Twenty-one patients were evaluable for response; 1/15 ACC (ORR: 7%); 1/4 SDC and 0/2 patients with other miscellaneous SGC responded. Median progression-free survival was 9.4 months (95% confidence interval [CI] 7.4-11.4 months), 7.2 months (95%CI 0.0-15.1) and 6.9 months (95%CI 0.0-15.1), respectively. CONCLUSION: This study showed too many severe cabozantinib-associated wound complications in patients with SGC, especially in prior irradiated areas. Therefore, the study closed prematurely. The efficacy in the limited number of evaluable patients was low to moderate. TRIAL REGISTRATION: This trial was registered on ClinicalTrials.gov: NCT03729297

Climate adaptation of interconnected infrastructures: a framework for supporting governance

Infrastructures are critical for human society, but vulnerable to climate change. The current body of research on infrastructure adaptation does not adequately account for the interconnectedness of infrastructures, both internally and with one another. We take a step toward addressing this gap through the introduction of a framework for infrastructure adaptation that conceptualizes infrastructures as complex socio-technical “systems of systems” embedded in a changing natural environment. We demonstrate the use of this framework by structuring potential climate change impacts and identifying adaptation options for a preliminary set of cases—road, electricity and drinking water infrastructures. By helping to clarify the relationships between impacts at different levels, we find that the framework facilitates the identification of key nodes in the web of possible impacts and helps in the identification of particularly nocuous weather conditions. We also explore how the framework may be applied more comprehensively to facilitate adaptation governance. We suggest that it may help to ensure that the mental models of stakeholders and the quantitative models of researchers incorporate the essential aspects of interacting climate and infrastructure systems. Further research is necessary to test the framework in these contexts and to determine when and where its application may be most beneficial.Infrastructure Networks Climate Adaptation and Hotspots. Knowledge for Climate Progra

Increased genetic contribution to wellbeing during the COVID-19 pandemic

Physical and mental health are determined by an interplay between nature, for example genetics, and nurture, which encompasses experiences and exposures that can be short or long-lasting. The COVID-19 pandemic represents a unique situation in which whole communities were suddenly and simultaneously exposed to both the virus and the societal changes required to combat the virus. We studied 27,537 population-based biobank participants for whom we have genetic data and extensive longitudinal data collected via 19 questionnaires over 10 months, starting in March 2020. This allowed us to explore the interaction between genetics and the impact of the COVID-19 pandemic on individuals' wellbeing over time. We observe that genetics affected many aspects of wellbeing, but also that its impact on several phenotypes changed over time. Over the course of the pandemic, we observed that the genetic predisposition to life satisfaction had an increasing influence on perceived quality of life. We also estimated heritability and the proportion of variance explained by shared environment using variance components methods based on pedigree information and household composition. The results suggest that people's genetic constitution manifested more prominently over time, potentially due to social isolation driven by strict COVID-19 containment measures. Overall, our findings demonstrate that the relative contribution of genetic variation to complex phenotypes is dynamic rather than static

Biosubstraat : Duurzaam substraat op basis van BioFoam

Doelstelling van het project was het ontwikkelen van een hernieuwbare grondstof/substraat, welke voldoet aan de wensen en eisen van de kwekers en waar een kwalitatief goed product op geteeld kan worden met handhaving of verbetering van het rendement. Het belangrijkste eindproduct is een bio substraat op basis van gemodificeerde BioFoam. De volgende activiteiten hebben bijgedragen aan het realiseren van de doelstelling: • Het ontwikkelen en produceren van diverse varianten gemodificeerde BioFoam en het uitvoeren van een aantal fysische en chemische testen in het laboratorium. • Het bepalen van belangrijke eigenschappen van deze gemodificeerde BioFoam als substraat in combinatie en vergelijking tot andere grondstoffen in het laboratorium • Het uitvoeren van diverse teeltproeven met mengsels van BioFoam met andere grondstoffen • Het in beeld brengen van de voordelen met betrekking tot de ketenkosten. Er is maar een teeltjaar (alleen 2012) gebruikt om testen uit te voeren. Ketens moeten daarom nog deels opgezet worden. • Op basis van de (teelt)proeven zijn wel meer partijen bij het project betrokken geraakt en heeft de markt belangstelling getoond. Het belangrijkste eindproduct is een getest substraat op basis van gemodificeerde BioFoam

Characterising Radio Telescope Software With the Workload Characterisation Framework

We present a modular framework, the Workload Characterisation Framework (WCF), that is developed to obtain, store and compare key characteristics of radio astronomy processing software in a reproducible way. As a demonstration, we discuss the experiences using the framework to characterise a LOFAR calibration and imaging pipeline.Instrumentatio