1,138 research outputs found

    Ontology-based model abstraction

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    In recent years, there has been a growth in the use of reference conceptual models to capture information about complex and critical domains. However, as the complexity of domain increases, so does the size and complexity of the models that represent them. Over the years, different techniques for complexity management in large conceptual models have been developed. In particular, several authors have proposed different techniques for model abstraction. In this paper, we leverage on the ontologically well-founded semantics of the modeling language OntoUML to propose a novel approach for model abstraction in conceptual models. We provide a precise definition for a set of Graph-Rewriting rules that can automatically produce much-reduced versions of OntoUML models that concentrate the models’ information content around the ontologically essential types in that domain, i.e., the so-called Kinds. The approach has been implemented using a model-based editor and tested over a repository of OntoUML models

    Städernas flora och fauna

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    År 1950 levde en tredjedel av världens befolkning i städer, sedan fem år tillbaka bor hälften i städer och allt tyder på att år 2030 bor två tredjedelar av alla människor i städer. År 2050 skulle det innebära 6,5 miljarder stadsbor. Fram till år 2030 kommer det att byggas mer sammanhängande stadsbebyggelse än vad det finns totalt idag. Det innebär enorma infrastrukturomställningar och stora arealer av mark kommer att tas i anspråk. Den mark som bebyggs är ofta mycket dåligt inventerad på djur och natur trots att forskning visar på höga värden i och omkring tätorter. Behovet av en kunskapsbas är stort

    All about the marine/sea ice diatom Nitzschia lecointei

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    Generally, in terms of growth N. lecointei seems quite tolerant to changes in pH and pCO2, probably due to the fact that this species grows in an environment with large seasonal variations in the carbonate system. However, increased pCO2 resulted in physiological changes that may have important ecological consequences, such as cellular stoichiometry. For instance, we observed changes in carbon metabolism, and fatty acid content and composition, that did not affect the growth rate. When the experimental period was increased (194 days, ca. 60 asexual generations), we observed a small reduction in growth at 960 µatm pCO2 after 147 days. Carbon metabolism was significantly affected, resulting in higher cellular release of dissolved organic carbon. When studying the synergism between temperature (−1.8 and 2.5°C) and pCO2 (390 and 960 μatm), synergism was detected in growth rate and acyl lipid fatty acid content. Carbon enrichment only promoted (3 %) growth rate closer to the optimal growth, but not at the control temperature (−1.8°C). Optimal growth rate was observed around 5°C in a separate experiment. The total content of fatty acids was reduced at elevated pCO2, but only at the control temperature. PUFAs were reduced at high pCO2. When combining increased temperature and different salinity conditions, the growth rate was higher at 3°C than at -1.8°C. Salinity 10 clearly limited growth rate and the highest growth rates were found at salinity 20 and 35. In another experiment, high and low temperature together with treatments simulating ice formation and melting conditions were studied. Here, the highest levels of oxidative stress were found in low temperature and ice melting treatments, respectively. With respect to 9 weeks in the dark, cell numbers were higher at -1.5°C compared to 3°C, but when retrieved to light conditions, after one week higher cell numbers were observed at 3°C versus -1.5°C. Furthermore, cell numbers were lower when acetateUniversidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Myrarnas areal och vegetation

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    NILS är ett rikstäckande miljöövervakningsprogram som följer tillstånd och förändringar i det svenska landskapet och hur dessa påverkar förutsättningarna för den biologiska mångfalden. NILS finansieras av Naturvårdsverket, där NILS ingår i programområde Landskap. Ett viktigt syfte med NILS är att följa upp de nationella miljökvalitetsmålen för olika naturtyper och fungera som underlag för att till exempel visa om genomförda miljövårdsåtgärder leder till önskade förbättringar på nationell nivå eller landsdelsnivå. När NILS första femåriga inventeringsperiod (2003-2007) nu har avslutas kan de första tillförlitliga skattningarna göras, baserat på NILS hela nationella stickprov. Efter nästa femårsperiod (2008-2012), när alla rutor har inventerats ännu en gång, kan vi dessutom göra skattningar av förändringar. Denna rapport presenterar resultat för myrar och andra torvmarker baserat på provyteinventeringen i NILS för åren 2003-2007. Dessa data kompletterar väl de som har kommit fram genom den rikstäckande Våtmarksinventeringen (VMI) som inte omfattar alla myrar eftersom varje län har satt en minsta storleksgräns för vilka som ska ingå (Gunnarsson & Löfroth 2009). Syftet med VMI var att göra en heltäckande kartering av Sveriges myrar, som underlag för att identifiera vilka myrarealer som är skyddsvärda, med höga naturvärden, och vilka som skulle kunna bli aktuella för exploatering genom t.ex. torvtäkt. Därför valde man att fokusera på lite större myrar. Den minimistorlek som valdes som gräns är i många län 10 hektar, och i norra Sverige 50 hektar (Westerberg & Rynbäck Andersson, 2004). NILS har däremot en minsta karteringsenhet på 0,1 hektar (Esseen m.fl. 2007, Allard m.fl. 2003), vilket innebär att även mindre myrar kommer med i urvalet. NILS kan därmed komplettera de befintliga dataunderlagen och ge ett bra underlag för att skatta förändringar för alla arealklasser och alla regioner. Särskilt för fjällen finns det i dagsläget ingen detaljerad information om mängden myrar. Riksinventeringen av skog (RIS), där Riksskogstaxeringen och Markinventeringen ingår, har ett stort stickprov av provytor för skog och andra naturtyper, men gör som regel inga fältbesök i fjällen ovanför barrskogsgränsen, och därför fyller NILS en särskilt viktig funktion just där. I NILS ingår också ett större urval av växtarter som är typiska för myrar, t.ex. vitmossor och andra våtmarksmossor. Detta är alltså den första rapporten som presenterar representativa och detaljerade data för myrar i hela fjällregionen, utifrån fältinventering med tydliga urvalskriterier. För myrar nedanför fjällen kan RIS och NILS stickprov tillsammans ge ett bra underlag för noggranna analyser av tillstånd och förändringar. Fältinventeringen i NILS är utformad för att ge ett bra och detaljerat underlag för att beskriva artförekomst och förändringar i markvegetationen, vilket är särskilt viktigt i fjällen, i jordbrukslandskapet och i myrar. Ytterligare ett syfte med denna rapport är alltså att ge en detaljerad bild av myrarnas vegetation i olika delar av landet, på ett sätt som tidigare inte har varit möjligt. Tidigare har data om arealer av torvmark, träd- och buskskikt samt många markvariabler kunnat tas fram via Riksskogstaxeringen (Hånell 1990). Syftet med denna rapport är alltså att ge en nyanserad och heltäckande bild av myrarnas areal, vegetation och artinnehåll samt olika typer av påverkan i Sverige och illustrera hur NILS provytedata kan bidra till en sådan beskrivning, genom att: beräkna arealer utifrån enhetliga kriterier i hela landet, inklusive fjällen jämföra de beräknade arealerna med tidigare uppgifter från andra datakällor jämföra några olika avgränsningskriterier utifrån vegetation och arealer presentera en detaljerad beskrivning av myrarnas vegetation, baserad på enhetlig fältmetodik presentera skattningar av mängder för växtarter i träd-, busk-, fält- och bottenskikt uppskatta mängden av påverkan från diken och markstörning utifrån registreringar i provyto

    The early life microbiota protects neonatal mice from pathological small intestinal epithelial cell shedding

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    The early life gut microbiota plays a crucial role in regulating and maintaining the intestinal barrier, with disturbances in these communities linked to dysregulated renewal and replenishment of intestinal epithelial cells. Here we sought to determine pathological cell shedding outcomes throughout the postnatal developmental period, and which host and microbial factors mediate these responses. Surprisingly, neonatal mice (Day 14 and 21) were highly refractory to induction of cell shedding after intraperitoneal administration of liposaccharide (LPS), with Day 29 mice showing strong pathological responses, more similar to those observed in adult mice. These differential responses were not linked to defects in the cellular mechanisms and pathways known to regulate cell shedding responses. When we profiled microbiota and metabolites, we observed significant alterations. Neonatal mice had high relative abundances of Streptococcus, Escherichia, and Enterococcus and increased primary bile acids. In contrast, older mice were dominated by Candidatus Arthromitus, Alistipes, and Lachnoclostridium, and had increased concentrations of SCFAs and methyamines. Antibiotic treatment of neonates restored LPS-induced small intestinal cell shedding, whereas adult fecal microbiota transplant alone had no effect. Our findings further support the importance of the early life window for microbiota-epithelial interactions in the presence of inflammatory stimuli and highlights areas for further investigation

    Complex Politics: A Quantitative Semantic and Topological Analysis of UK House of Commons Debates

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    This study is a first, exploratory attempt to use quantitative semantics techniques and topological analysis to analyze systemic patterns arising in a complex political system. In particular, we use a rich data set covering all speeches and debates in the UK House of Commons between 1975 and 2014. By the use of dynamic topic modeling (DTM) and topological data analysis (TDA) we show that both members and parties feature specific roles within the system, consistent over time, and extract global patterns indicating levels of political cohesion. Our results provide a wide array of novel hypotheses about the complex dynamics of political systems, with valuable policy applications

    Swedish Personal Names in America

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    Evidence-based urban greening: a missing piece in biodiversity conservation

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    With calls for increased greenery in cities to safeguard biodiversity and its associated benefits to humans, urban vegetation must be managed carefully and efficiently. It is time to change paths from current spurious attempts to manufacture resilience and instead usher in evidence-based urban greening to secure ecosystems for the future

    Landscape and soundscape quality promote stress recovery in nearby urban nature: A multisensory field experiment

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    Cities have different benefits and risks, but are often stressful environments to live in. Everyday contact with nearby nature can be a crucial way to alleviate stress and increase the well-being of citizens. However, there is still limited evidence on how nature-health benefits vary according to the type and quality of natural environments. This study integrated multiple landscape and soundscape objective and perceived assessments to examine stress recovery in different types of neighbourhood nature. We used a field randomised experiment (n=45) to analyse effects of various random and fixed factors on restoration including: environmental conditions (e.g. temperature, wind, air quality), personal characteristics (e.g. age, gender, perceived health, nature connectedness), presence of other people and environmental quality (e.g. Perceived Environmental Aesthetic Qualities Scale and Perceived Sound Affective Quality scale). We found that physiological and psychological restoration is significantly greater in sites with higher visual (% visual natural elements) and acoustic (Normalized Difference Soundscape Index (NDSI)) naturalness i.e. the beach and forest, compared to the urban park (control site). Perceived landscape and soundscape quality were strongly associated with stress recovery, and these results were more pronounced for the soundscape. This highlights that soundscape quality assessments deserve more systematic attention in urban green infrastructure research and planning. Finally, we found important early evidence of reduction in Electrodermal activity (EDA) only within 3 minutes of nature exposure especially in the forest

    Chirping across continents: Variation in House Sparrow (Passer domesticus) vocalizations across North America and Europe

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    The house sparrow (Passer domesticus) is one of the most widespread invasive bird species, with numerous and dense populations established across urban-agricultural landscapes of North America. Although this species has been widely studied to identify the traits that explain its global ubiquity, descriptions of house sparrow acoustic features across its native and introduced range are limited in the literature. We recorded male house sparrow vocalizations from 13 cities across Europe and North America to quantify the structural features of its common “chirrup” vocalization. Although the basic structure and duration were consistent across the two geographic regions, the vocalizations differed in their minimum frequencies and bandwidth. In a post hoc analysis of 140 museum specimens, we found that European house sparrows had larger bills and bodies than those in North America. Thus, we propose that these frequency shifts could be a result of synergistic interactions between morphological differences, potential differences in ambient noise, acoustic overlap with other species within the soundscape, or other acoustic features of European and North American cities. House sparrows seem to be a good model for future bioacoustics studies, given their worldwide distribution and acoustic plasticity, to test hypotheses related to urbanization traits and invasion potential
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