179 research outputs found

    Towards a Proof Theory of G\"odel Modal Logics

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    Analytic proof calculi are introduced for box and diamond fragments of basic modal fuzzy logics that combine the Kripke semantics of modal logic K with the many-valued semantics of G\"odel logic. The calculi are used to establish completeness and complexity results for these fragments

    Phylogeography of the Microcoleus vaginatus (Cyanobacteria) from Three Continents – A Spatial and Temporal Characterization

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    It has long been assumed that cyanobacteria have, as with other free-living microorganisms, a ubiquitous occurrence. Neither the geographical dispersal barriers nor allopatric speciation has been taken into account. We endeavoured to examine the spatial and temporal patterns of global distribution within populations of the cyanobacterium Microcoleus vaginatus, originated from three continents, and to evaluate the role of dispersal barriers in the evolution of free-living cyanobacteria. Complex phylogeographical approach was applied to assess the dispersal and evolutionary patterns in the cyanobacterium Microcoleus vaginatus (Oscillatoriales). We compared the 16S rRNA and 16S-23S ITS sequences of strains which had originated from three continents (North America, Europe, and Asia). The spatial distribution was investigated using a phylogenetic tree, network, as well as principal coordinate analysis (PCoA). A temporal characterization was inferred using molecular clocks, calibrated from fossil DNA. Data analysis revealed broad genetic diversity within M. vaginatus. Based on the phylogenetic tree, network, and PCoA analysis, the strains isolated in Europe were spatially separated from those which originated from Asia and North America. A chronogram showed a temporal limitation of dispersal barriers on the continental scale. Dispersal barriers and allopatric speciation had an important role in the evolution of M. vaginatus. However, these dispersal barriers did not have a permanent character; therefore, the genetic flow among populations on a continental scale was only temporarily present. Furthermore, M. vaginatus is a recently evolved species, which has been going through substantial evolutionary changes

    Bayesian Probability and Statistics in Management Research: A New Horizon

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    This special issue is focused on how a Bayesian approach to estimation, inference, and reasoning in organizational research might supplement—and in some cases supplant—traditional frequentist approaches. Bayesian methods are well suited to address the increasingly complex phenomena and problems faced by 21st-century researchers and organizations, where very complex data abound and the validity of knowledge and methods are often seen as contextually driven and constructed. Traditional modeling techniques and a frequentist view of probability and method are challenged by this new reality

    Sinteza i vrednovanje analgetskog, protuupalnog i ulcerogenog djelovanja nekih triazolo- i 2-pirazolil-pirido[2,3-d]-pirimidina

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    New series of 2-hydrazino-7,8-dihydro-6H-cyclopenta[5,6]pyrido[2,3-d]pyrimidines and its 1,7,8,9-tetrahydrocyclopenta[5,6]pyrido[2,3-d][1,2,4]triazolo[4,3-a]pyrimidine, 1,7,8,-9-tetrahydrocyclopenta[5,6]pyrido[2,3-d][1,2,3,4]tetrazolo[4,5-a]pyrimidine, 8,9-dihydro-7H-cyclopenta[5,6]pyrido[2,3-d]imidazolo[1,2-a]pyrimidine, 2-(pyrazol-1-yl)-7,8-dihydro-6H-cyclopenta[5,6]pyrido[2,3-d]pyrimidine derivatives were prepared in order to obtain new compounds with potential anti-inflammatory and analgesic activity and low ulcerogenic effect. The compounds possessing potent anti-inflammatory activity were further tested for their analgesic and ulcerogenic activities. Compounds 3-amino-6-(4-aryl)-9-(4-arylmethylene)-cyclopenta[5,6]pyrido[2,3-d][1,2,4]triazolo[4,3-a]pyrimidin-5(H)-one (4c), 1-amino-2-methyl-6-(4-aryl)-9-(4-aryl-methylene)-cyclopenta[5,6]pyrido[2,3-d]imidazolo[1,2-a]pyrimidin-5(H)-one (6a), 2-amino-5-(4-aryl)-8-(4-arylmethylene)-cyclopenta[5,6]pyrido[2,3-d]pyrimidine-4(H)-one (9), 2-(3-amino-5-hydroxypyrazol-1-yl)-5-(4-aryl)-8-(4-arylmethylene)-cyclopenta[5,6]-pyrido[2,3-d]pyrimidin-4(H)-one (10a) and 3-thioxo-6-(4-aryl)-9-(4-arylmethylene)-cyclopenta[5,6]pyrido[2,3-d][1,2,4]triazolo[4,3-a]pyrimidin-5(H)-one (13) showed significant analgesic effects. Compound 2-(3-amino-5-hydroxypyrazol-1-yl)-5-(4-aryl)-8-(4-arylmethylene)-cyclopenta[5,6]pyrido[2,3-d]pyrimidin-4(H)-one (10a) was evaluated as the lead compound having higher anti-inflammatory activity (82.8%) than ibuprofen (79.5%) and lower ulcerogenic effect.U radu je opisana sinteza serije 2-hidrazino-7,8-dihidro-6H-ciklopenta[5,6]pirido[2,3-d]pirimidina i njihovih 1,7,8,9-tetrahidrociklopenta[5,6]pirido[2,3-d][1,2,4]triazolo[4,3-a]pirimidinskih, 1,7,8,9-tetrahidrociklopenta[5,6]pirido[2,3-d][1,2,3,4]tetrazolo[4,5-a]pirimidinskih, 8,9-dihidro-7H-ciklopenta[5,6]pirido[2,3-d]imidazolo[1,2-a]pirimidinskih i 2-(pirazol-1-il)-7,8-dihidro-6H-ciklopenta[5,6]pirido[2,3-d]pirimidinskih derivata s potencijalnim protuupalnim i analgetskim te manjim ulcerogenim djelovanjem. Spojevima s izraženim protuupalnim djelovanjem testirano je analgetsko i ulcerogeno djelovanje. Spojevi 3-amino-6-(4-aril)-9-(4-arilmetilen)-ciklopenta[5,6]pirido[2,3-d][1,2,4]triazolo[4,3-a]pirimidin-5(H)-on (4c), 1-amino-2-metil-6-(4-aril)-9-(4-aril-metilen)-ciklopenta[5,6]pirido[2,3-d]imidazolo[1,2-a]pirimidin-5(H)-on (6a), 2-amino-5-(4-aril)-8-(4-arilmetilen)-ciklopenta[5,6]pirido[2,3-d]pirimidin-4(H)-on (9), 2-(3-amino-5-hidroksipirazol-1-il)-5-(4-aril)-8-(4-arilmetilen)- ciklopenta[5,6]-pirido[2,3-d]pirimidin-4(H)-on (10a) i 3-tiokso-6-(4-aril)-9-(4-arilmetilen)-ciklopenta[5,6]pirido[2,3-d][1,2,4]triazolo[4,3-a]pirimidin-5(H)-on (13) pokazali su značajno analgetsko djelovanje. Spoj 2-(3-amino-5-hidroksipirazol-1-il)-5-(4-aril)-8-(4-arilmetilen)-ciklopenta[5,6]pirido[2,3-d]pirimidin-4(H)-on (10a) je vodeći spoj s jačim protuupalnim djelovanjem (82,8%) od ibuprofena (79,5%), a slabijim ulcerogenim djelovanjem

    Soil protistology rebooted: 30 fundamental questions to start with

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    Protists are the most diverse eukaryotes. These microbes are keystone organisms of soil ecosystems and regulate essential processes of soil fertility such as nutrient cycling and plant growth. Despite this, protists have received little scientific attention, especially compared to bacteria, fungi and nematodes in soil studies. Recent methodological advances, particularly in molecular biology techniques, have made the study of soil protists more accessible, and have created a resurgence of interest in soil protistology. This ongoing revolution now enables comprehensive investigations of the structure and functioning of soil protist communities, paving the way to a new era in soil biology. Instead of providing an exhaustive review, we provide a synthesis of research gaps that should be prioritized in future studies of soil protistology to guide this rapidly developing research area. Based on a synthesis of expert opinion we propose 30 key questions covering a broad range of topics including evolution, phylogenetics, functional ecology, macroecology, paleoecology, and methodologies. These questions highlight a diversity of topics that will establish soil protistology as a hub discipline connecting different fundamental and applied fields such as ecology, biogeography, evolution, plant-microbe interactions, agronomy, and conservation biology. We are convinced that soil protistology has the potential to be one of the most exciting frontiers in biology

    Tundra Trait Team: A database of plant traits spanning the tundra biome

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    Abstract Motivation: The Tundra Trait Team (TTT) database includes field-based measurements of key traits related to plant form and function at multiple sites across the tundra biome. This dataset can be used to address theoretical questions about plant strategy and trade-offs, trait–environment relationships and environmental filtering, and trait variation across spatial scales, to validate satellite data, and to inform Earth system model parameters. Main types of variable contained: The database contains 91,970 measurements of 18 plant traits. The most frequently measured traits (> 1,000 observations each) include plant height, leaf area, specific leaf area, leaf fresh and dry mass, leaf dry matter content, leaf nitrogen, carbon and phosphorus content, leaf C:N and N:P, seed mass, and stem specific density. Spatial location and grain: Measurements were collected in tundra habitats in both the Northern and Southern Hemispheres, including Arctic sites in Alaska, Canada, Greenland, Fennoscandia and Siberia, alpine sites in the European Alps, Colorado Rockies, Caucasus, Ural Mountains, Pyrenees, Australian Alps, and Central Otago Mountains (New Zealand), and sub-Antarctic Marion Island. More than 99% of observations are georeferenced. Time period and grain: All data were collected between 1964 and 2018. A small number of sites have repeated trait measurements at two or more time periods. Major taxa and level of measurement: Trait measurements were made on 978 terrestrial vascular plant species growing in tundra habitats. Most observations are on individuals (86%), while the remainder represent plot or site means or maximums per species. Software format: csv file and GitHub repository with data cleaning scripts in R; contribution to TRY plant trait database (www.try-db.org) to be included in the next version release
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