713 research outputs found
Code & Data for: Environmental heterogeneity can tip the population genetics of range expansions
No full textCode & Data for: Environmental heterogeneity can tip the population genetics of range expansions (Matti Gralka & Oskar Hallatschek), under review at Elife (2019)
Data accompanying the manuscript "Mechanical interactions in bacterial colonies and the surfing probability of beneficial mutations"
No full textWaclaw, Bartlomiej; Gralka, Matti; Hallatschek, Oskar; Farrell, Fred. (2017). Data accompanying the manuscript "Mechanical interactions in bacterial colonies and the surfing probability of beneficial mutations", 2015-2016 [dataset]. University of Edinburgh. School of Physics and Astronomy. ICMCS. http://dx.doi.org/10.7488/ds/1702
Poliisin yhteiskuntavastuu - pohdiskelua organisaatiotutkimuksen ja Matti Yrjänä Joensuun romaanien pohjalta
Get PDFThe article describes the societalresponsibility of the police administration fromtwo viewpoints: how it is present inadministrative science and administrativeculture of the police and what kind of picturecan be found in the Finnish detective novelswritten by Matti Yrjänä Joensuu. The focus ofthe article is to make administrative scientificand literal viewpoints to discuss with eachothers. The article is created by tworesearchers. Markku Temmes aims to useadministrative science which emphasizes therole of the police as a basic organisation inthe society and in the politico-administrativesystem. The second author of the articleVoitto Ruohonen has in this article and in hisdissertation tackled the societal picture of thenovels by Matti Yrjänä Joensuu from viewpointof literature and sociological research
Searching for Principles of Microbial Ecology Across Levels of Biological Organization
No full textSynopsis Microbial communities play pivotal roles in ecosystems across different scales, from global elemental cycles to household food fermentations. These complex assemblies comprise hundreds or thousands of microbial species whose abundances vary over time and space. Unraveling the principles that guide their dynamics at different levels of biological organization, from individual species, their interactions, to complex microbial communities, is a major challenge. To what extent are these different levels of organization governed by separate principles, and how can we connect these levels to develop predictive models for the dynamics and function of microbial communities? Here, we will discuss recent advances that point towards principles of microbial communities, rooted in various disciplines from physics, biochemistry, and dynamical systems. By considering the marine carbon cycle as a concrete example, we demonstrate how the integration of levels of biological organization can offer deeper insights into the impact of increasing temperatures, such as those associated with climate change, on ecosystem-scale processes. We argue that by focusing on principles that transcend specific microbiomes, we can pave the way for a comprehensive understanding of microbial community dynamics and the development of predictive models for diverse ecosystems
Benchmarking and the bottom line
No full textMatti Siemiatycki presents the case for expanding and formalising performance benchmarking processes to address the persistent problems of escalating costs and missed deadlines in infrastructure and public works projects Copyright (c) 2009 The Author. Journal compilation (c) 2009 ippr.
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Evolutionary dynamics in microbial colonies
Get PDFTraditionally, evolutionary biology has mostly taken a retrospective view, looking backwards in time to infer past evolutionary dynamics. Over the past 30 years, evolution experiments in the laboratory have become a valuable complementary technique to study evolution in real time. Microbial populations in shaken flasks are an ideal model system to do this, because their short generation times and easy reproducibility allow for the study of dozens to hundreds of replicates. Our understanding of microbial evolution in these simple laboratory environments has dramatically improved in recent years.Microbial populations in the wild face vastly more complex conditions: they grow as spatially structured communities called microbial biofilms, often consisting of interacting mixtures of different species fulfilling different purposes, subject to various, potentially self-generated, biophysicochemical gradients of, e.g., oxygen or nutrients, which are in turn altered by the physical structure of the community. In short, natural population are subject to a vast variety of ecological interactions, and it has remained unclear how much can be learned from well-mixed liquid culture experiments about how ecology affects evolution in more complex scenarios. In this dissertation, I approach this question using one of the simplest possible ecological aspects: the fact that most populations grow in spatially structured communities. Using microbial colonies as an experimental model system, I examine the effect of spatial structure on evolutionary dynamics in a variety of ways. First, Chapters 2-4 investigate the fates of neutral mutations and the dynamics of beneficial mutations in microbial colonies to find that both the neutral diversity resulting from spontaneous mutations and the strength of adaptation is increased in colonies compared to microbial populations grown in shaken flasks. The second half of the thesis is concerned with the effects of environmental heterogeneity on evolutionary dynamics. In Chapter 5, randomly disordered environments are used to examine the competition of selection and extrinsic noise in a model system for spontaneous beneficial and deleterious mutations. In these experiments, extrinsic noise can almost entirely overpower selection such that beneficial variants cannot leverage their advantage to further their evolutionary success. Chapter 6 discusses the effects of gradients on the emergence of antibiotic resistance and how convective flow can shape the trade-off between selection for resistance and the efficacy of treatment. Overall, the results presented in this thesis suggest that spatial structure can have a momentous influence on the evolutionary dynamics of many dense cellular populations like biofilms and tumors: not only do the dynamics of adaptation change quantitatively in spatially structured populations, but qualitatively different patterns of evolutionary dynamics emerge that cannot arise in well-mixed population. Environmental heterogeneity can also have a strong influence on the speed and the direction of adaptation: whereas random heterogeneity in the environment prevents the spread of beneficial variants, the presence of antibiotic gradients can facilitate the rapid emergence of resistance. This work thus offers a glimpse into the profound and complex ways in which ecology can impact evolution even in simple model systems
Sudden Death Associated with Incarcerated Small Bowel due to Mesodiverticular Band
No full textMeckel’s diverticulum is a congenital anomaly present in about 3% of the population and usually asymptomatic. Rarely, a mesodiverticular band extends from the tip of a Meckel’s diverticulum to the mesentery, thought to be due to lack of involution of the left vitelline artery. The presence of this band creates a closed loop through which loops of bowel can become entrapped. Rare case reports have described incarceration of bowel, and sudden death in children. We present such a case, and discuss this entity.Peer reviewe
Matti Aikio - verk og virke
No full textDenne avhandlingen studerer de litterære verkene til den samiske forfatteren Matti Aikio, samt det nedslag hans verk hadde i samtidens Norge. Aikios romaner, artikler, skuespill og billedkunst ble skapt i tidsrommet 1904-29, en periode da Norge som ny selvstendig nasjonalstat hadde begrenset toleranse med sin samiske minoritet. En slik etnisk kultur-forståelse var i samsvar med samtidens rådende sosial-darwinisme, på overgangen fra kolonialisme til imperialisme. I slike omgivelser fremsto Matti Aikio som norsk forfatter med bøker skrevet på norsk – men med et selvvalgt samisk-lydende kunstnernavn. Det er avhandlingens mål å avdekke en mulig notsetningen mellom storsamfunnets forventning om assimilasjon og Aikios diskrete presentasjon av samiske verdier i sitt verk og virke. Det blir diskutert om nettopp valg av virkemidler førte til mistenkeliggjøring fra samtidens samiske talsmenn, men at ettertiden har vist at Aikios insistering på samarbeidslinje ville gi bedre langsiktige resultater for samisk språk og kultur. Samtidig søker analysen å underbygge at Aikio selv fikk en økt forståelse for den samiske kulturens mangfold i løpet av sin karriere – samtidig som taktikken endret seg i forfatterens langsiktige strategi om full likestilling for den samiske minoriteten. Fra å hevde at den ekte samiske kulturen bare fantes i Karasjok, endte han med en mer moderne og inkluderende forståelse av en samisk folkegruppe med et mangfold av språk og kulturuttrykk.This dissertation is a study of the literary works by the Sami author Matti Aikio, and of the impact his work had in Norway in his time. Aikio’s novels, articles, dramas and paintings were produced in the time period 1904−1929, a period when Norway as an independent nation state had limited tolerance for its Sami minority. Such an ethnic cultural understanding corresponded with the prevailing sentiment of social Darwinism of the time, in the transition from colonialism to imperialism. In this context Matti Aikio emerged as a Norwegian author with books written in Norwegian – but under a personally chosen, Sami sounding nom de plume. The objective of the dissertation is to disclose a possible contradiction between greater society’s expectations regarding assimilation and Aikio’s discreet presentation of Sami values in his literary works and professional activity. It has been discussed whether precisely the choice of tools at hand served to undermine his credibility with the Sami spokesmen of the time, but after the fact it has become evident that Aikio’s insistence on a collaborative line would have far better long-term results for the Sami language and culture. The analysis simultaneously seeks to substantiate that Aikio personally acquired a greater understanding of the diversity of the Sami culture in the course of his career – while simultaneously the tactics of the author’s long-term strategy for full equality for the Sami minority changed. From maintaining that the true Sami culture was found only in Karasjok, he ended up with a more modern and inclusive understanding of a Sami ethnic group with a multitude of languages and cultural expressions
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