12,476 research outputs found
Complex scale-free networks with tunable power-law exponent and clustering
No full textThis article is made available through the Brunel Open Access Publishing Fund. It is distributed under a Creative Commons License (http://creativecommons.org/licenses/by/3.0/). Copyright @ 2013 Elsevier B.V.We introduce a network evolution process motivated by the network of citations in the scientific literature. In each iteration of the process a node is born and directed links are created from the new node to a set of target nodes already in the network. This set includes mm “ambassador” nodes and ll of each ambassador’s descendants where mm and ll are random variables selected from any choice of distributions plpl and qmqm. The process mimics the tendency of authors to cite varying numbers of papers included in the bibliographies of the other papers they cite. We show that the degree distributions of the networks generated after a large number of iterations are scale-free and derive an expression for the power-law exponent. In a particular case of the model where the number of ambassadors is always the constant mm and the number of selected descendants from each ambassador is the constant ll, the power-law exponent is (2l+1)/l(2l+1)/l. For this example we derive expressions for the degree distribution and clustering coefficient in terms of ll and mm. We conclude that the proposed model can be tuned to have the same power law exponent and clustering coefficient of a broad range of the scale-free distributions that have been studied empirically.EPSR
Hidden in plain sight
No full textBelgië staat bekend voor de productie van XTC en (meth)amfetamine. De productie is niet zonder gevaar en zorgt voor bergen afval dat illegaal wordt gedumpt en geloosd. Het afval schaadt zo onze natuur en gezondheid. Opsporen van deze labo’s en dumpingen is niet eenvoudig. Maar jij kan helpen door de signalen en geur ervan te leren herkennen! Charlotte Colman en Sophia De Seranno vertellen je er alles over
The formation and function of ER-endosome membrane contact sites
No full textRecent advances in membrane contact site (MCS) biology have revealed key roles for MCSs in inter-organellar exchange, the importance of which is becoming increasingly apparent. Roles for MCSs in many essential physiological processes including lipid transfer, calcium exchange, receptor tyrosine kinase signalling, lipid droplet formation, autophagosome formation, organelle dynamics and neurite outgrowth have been reported. The ER forms an extensive and dynamic network of MCSs with a diverse range of functionally distinct organelles. MCSs between the ER and endocytic pathway are particularly abundant, suggesting important physiological roles. Here, our current knowledge of the formation and function of ER contact sites with endocytic organelles from studies in mammalian systems is reviewed. Their relatively poorly defined molecular composition and recently identified functions are discussed. In addition, likely, but yet to be established, roles for these contacts in lipid transfer and calcium signalling are considered. This article is part of a Special Issue entitled: The cellular lipid landscape edited by Tim Levine and Anant K. Menon
Gedragsinzichten bieden meer beleidskansen dan er nu worden benut
No full textGedragsinzichten zijn onontbeerlijk om te komen tot effectief beleid, de mens is immers geen homo economicus. Dat geldt echter niet alleen voor uitvoeringsvraagstukken, maar ook voor het ontwerpen van beleid. Hier ligt er nog een groot onbenut potentieel.Policy Analysi
En studie av effekter av utbygging i Ildgruben reinbeitedistrikt
No full textIkrafttredelsen av Naturmangfoldloven i 2009 har gitt økt fokus på begrepet samlet belastning i norsk natur- og reindriftsforvaltning. Prinsippet kommer også til uttrykk gjennom forskriften for konsekvensutredninger, og setter krav til utredninger av dette temaet ovenfor reindrift (jf. FOR-2014-12-19-1726, Vedlegg IV). Kunnskapsnivået rundt samlet belastning og reindrift er midlertidig tynt og det er behov for forskning rundt dette temaet (Colman et al. [upublisert]).
I forbindelse med konsekvensutredninger av utbyggingstiltak i nyere tid, så har samlet belastning blitt vurdert for reindrift (eks. Arnesen 2015a & Colman et al. 2005). Vurderinger har blant annet blitt gjort på bakgrunn av skjønnsmessige vurderinger av situasjonen i det aktuelle distriktet og hvordan driften har måtte tilpasse seg som følge av annen virksomhet de siste tiårene (Arnesen 2015a).
I min masteroppgave har følgende problemstillinger vært gjenstand for undersøkelse: Vurdere begrepet samlet belastning og diskutere dets betydning for reindriftsforvaltningen, også i forbindelse med konsekvensutredninger. Via en casestudie i Ildgruben reinbeitedistrikt kartlegge om økt grad av tekniske inngrep i et historisk og nåtidig perspektiv har påvirket produksjonsgrunnlaget til reindriften, og med dette prøve å koble begrepet samlet belastning med reindriftens næringsgrunnlag.
Resultater fra min kvalitative studie viser at inngrepsgraden i Ildgruben reinbeitedistrikt har ført til store indirekte og direkte arealbeslag spesielt i vårbeite og kalvingsområder, hovedsakelig i perioden 1960-1990. I etterkant har utfordringer vært tilknyttet små vannkraftutbygginger, motorferdsel i utmark og økt menneskelig aktivitet inn i distriktets arealer, særlig i forbindelse med hytteområder. Videre viser resultatene at det i forbindelse med historiske endringer i produksjon- og næringsstall observeres få potensielle samlede effekter av utbygging på reindriften produksjon i Ilgruben reinbeitedistrikt. På denne bakgrunnen vurderes det også til at det er vanskelig å definere hvilken verdi utslag på reindriftens produksjon vil ha i en helhetlig vurdering av samlet belastning.
På bakgrunn av resultater og innhentet kunnskap anbefales det i oppgaven at det i fremtiden vil være et behov for en standardisert metodikk for vurdering av samlet belastning på reindrift, som inkluderer og isolerer de faktiske effektene av utbygging i et riktig tids og arealomfang. Tilslutt vil det også være et behov for vurderinger av hvilke forvaltningsorgan som skal ha ansvaret for en vurdering av samlet belastning på reindrift i en overordnet arealplanlegging.The introduction of the Nature Diversity Act in 2009 has given more attention to the concept of cumulative impact in Norwegian management on nature and reindeer husbandry. The principle is also expressed through regulations for impact assessments, and sets requirements for investigations of this topic on reindeer husbandry (see FOR-2014-12-19-1726, Vedlegg IV). The level of knowledge about cumulative impact and reindeer husbandry is temporarily thin, and there is a need for research on this topic (Colman et al. [Unpublished]).
In relations to impact assessments in recent times, cumulative impact has been assessed for reindeer husbandry (eg. Arnesen 2015a & Colman et al. 2005). Ratings have been made,
on the basis of discretionary assessments of the situation in the herding district, and how operations have had to adapt to other activities in the last decades (Arnesen 2015a).
In my master's thesis the following issues have been investigated: (1) Assessments of the concept of cumulative effects and its significance to reindeer husbandry management, especially in relations to impact assessments for development. (2) Through a case study in the Ildgruben reindeer herding district, assess to which degree increased human infrastructure and energy development in a historical and contemporary perspective has influenced the production base for reindeer husbandry.
Results from my qualitative study showed that the rate of intervention in the Ildgruben has led to large indirect and direct effects on spring pastures and calving areas, mainly in the period 1960-1990. More recent challenges have been associated with developments of small hydropowerplants, motocross in the wilderness, and increased human activity inside of the district's areas, especially in connection with the use of cabins and cottages. Furthermore, the results show that in conjunction with historical changes, there are observed only few or none potential effects of development on reindeer husbandry production in Ilgruben reindeer herding district. On this background, I concluded that it is difficult to define which value reindeer husbandry production impacts will have on a comprehensive assessment of cumulative impact in the future.
Based on the results and acquired knowledge, I also recommend that in the future there be a need for a standardized methodology for assessing cumulative impacts on reindeer husbandry, which includes and isolates the actual effects of development and in a correct frame of area and time. Finally, in future there will be a need for reassessments of which management authority which will be responsible for assessments of cumulative impacts in an overall planning on reindeer husbandry management.M-N
Embedding research (ER) led by nurses, midwives and allied health professionals (NMAHPs): the NMAHP-ER model.
No full textPrevious embedded researcher models have focused predominantly on an individual being a temporary team member and embedded for a project-limited short-term placement. To develop an innovative research capacity building model to address the challenges of developing, embedding and sustaining, research led by Nurses, Midwives, and Allied Health Professionals (NMAHPs) in complex clinical environments. This healthcare and academic research partnership model offers an opportunity to support the 'how' of enabling NMAHP research capacity building from within the researchers' clinical area of expertise. Collaboration between three healthcare and academic organisations and the iterative process of cocreation, development and refinement took place over 6 months during 2021. The collaboration relied on virtual meetings, emails, telephone calls and document review. A codesigned NMAHP embedded research (ER) model is ready for trialling with the individual being an existing clinician working collaboratively within the healthcare setting and with academia to develop the skills to become the ER. This model supports NMAHP-led research activity in clinical organisations in a visible and manageable way. As a shared, long-term vision, the model will contribute to research capacity and capability of the wider healthcare workforce. It will lead, facilitate and support research in and across clinical organisations in collaboration with higher education institutions. [Abstract copyright: © Author(s) (or their employer(s)) 2022. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.
Targeting the calcium ATPase to the endoplasmic reticulum
No full textThe sarco/endoplasmic reticulum calcium ATPase (SERCA) pumps calcium from thecytoplasm into the lumen of the endoplasmic or sarcoplasmic reticulum (ER/SR), removingexcess Ca2+ from the cytoplasm and replenishing ER/SR Ca2+ stores. SERCA is located inboth the ER and the ER-Golgi intermediate compartment, and so is likely maintained in theER by retrieval. To locate the ER retrieval signal(s) in SERCA, a series of chimeric calciumpumps have been constructed. Sections of SERCA were replaced with corresponding sequencefrom its plasma membrane counterpart; plasma membrane calcium ATPase (PMCA).Replacing the C-terminus of SERCA with corresponding PMCA sequence results inmistargeting of the protein to the plasma membrane. The opposite construct (consisting ofPMCA with the C-terminus replaced by that of SERCA) is located in the ER, suggesting thatthe ER retrieval signal lies towards the C-terminus of the protein. Many of the chimeras builtwere located in the ER. This is likely to be due to protein misfolding in some cases. Attemptswere made to detect the unfolded protein response in cells expressing chimeras by measuringlevels of the chaperone protein BiP. BiP upregulation was only seen when the unfoldedprotein response was induced pharmacologically, and not in cells expressing chimeras. Moresubtle mutagenesis was then carried out to assess the role of the tenth transmembrane domainof SERCA in ER retrieval and CD8 reporter constructs were used to study the tenthtransmembrane domains of SERCA and PMCA. The study then focussed on determining themechanism by which SERCA is retrieved to the ER. Rer1p and BAP31 are both candidatereceptors for the retrieval of SERCA. An antibody to two epitopes in human Rer1p was raisedand characterised. Immunoprecipitation and cross-linking showed that although Rer1p appearsnot to interact with SERCA, BAP31 shows a potential interaction and therefore could be involved in the retrieval of the calcium pump to the ER
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No full textN.B.: When citing this work, cite the original article. This is a pre-copy-editing, author-produced PDF of an article accepted for publication in Radiation Protection Dosimetry following peer review. The definitive publisher-authenticated version
Valt er geld te verdienen aan het voorspellen van Voetbaluitslagen?
No full textIn dit verslag is onderzocht of er geld te verdienen valt aan het spelen van online voetbaltoto. Er zijn twee modellen onderzocht; één op basis van onderlinge resultaten en de ander op basis van achtergrondvariabelen. Vervolgens zijn deze getest op fictieve en historische data en met elkaar vergeleken. Als conclusie is er gevonden dat er zeker een kans bestaat dat de modellen winstgevend kunnen zijn, maar dat er te weinig data is om dit met zekerheid te zeggen.StatisticsApplied mathematicsElectrical Engineering, Mathematics and Computer Scienc
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