973 resultados para PHYLOGENETIC-RELATIONSHIPS
Resumo:
Sekä organisaatiokulttuuria, luottamusta että innovatiivisuutta on tutkittu paljon, mutta toistaiseksi nämä käsitteet yhdistävää kokonaisvaltaista tutkimusta ei juuri ole tehty tai ainakaan raportoitu tieteellisissä julkaisuissa. Tätä tutkimus käsitteli organisaatiokulttuurin, luottamuksen ja innovatiivisuuden suhteita erilaisissa organisaatiokulttuureissa. Tutkimuksen tavoitteena oli tutkia organisaatiokulttuurin vaikutusta luottamukseen (sekä kompetenssiin, hyväntahtoisuuteen että rehellisyyteen perustuvaan lateraaliin, vertikaaliin ja institutionaaliseen luottamukseen), innovaatioilmastoon ja innovaatiotoiminnan tuloksellisuuteen. Organisaatiokulttuurin, luottamuksen ja innovatiivisuuden yhteyttä tarkasteltiin neljässä erityyppisessä organisaatiokulttuurissa (klaani-, adhokratia-, hierarkia- ja markkinakulttuurit), jotka pohjautuvat kilpailevien arvojen malliin. Tutkimuksen empiirinen osa toteutettiin posti ja Internet -pohjaisena kyselytutkimuksena 40 organisaatioyksikössä tilastollisen analyysin menetelmin. Yleisellä tasolla työssä saatiin selville, että luottamuksen ja innovatiivisuuden tasot vaihtelevat erityyppisissä organisaatio-kulttuureissa. Tarkemmin sanottuna klaani- ja adhokratiakulttuureissa luottamus ja innovatiivisuus olivat korkeita, ja näillä kulttuureilla oli myös positiivinen vaikutus innovaatiotoiminnan tuloksellisuuteen. Erityisesti institutionaalisen luottamuksen ja innovaatiotuen merkitykset olivat tärkeitä, sillä ne toimivat mediaattoreina organisaatiokulttuurin ja innovatiivisuuden välisessä suhteessa. Luottamuksella ja innovatiivisuudelle ei sitä vastoin ollut vaikutusta hierarkia- ja markkinakulttuureissa, tai vaikutus oli negatiivinen. Tässä työssä osoitettiin myös aiemmin hyvin vähän tutkitun institutionaalisen organisatorisen luottamuksen merkitys organisaatioiden innovatiivisuudessa.
Resumo:
Tutkielman tarkoituksena oli tarkastella hinnoittelun ja hinnanalennusten merkitystä toimittaja-asiakassuhteissa yritysmarkkinoilla, sekä sitä kuinka kilpailuoikeus säätelee hinnoittelua. Tutkielman ensisijaisena tavoitteena oli selvittää kuinka alennuspolitiikka tulisi laatia jotta se olisi EY:n kilpailuoikeuden mukaan sallittu. Aluksi hinnoittelupolitiikkaan ja strategiaan vaikuttavia seikkoja tarkasteltiin teoreettisesti ja tämän pohjalta laadittua viitekehystä sovellettiin empiiristä tutkimusta suoritettaessa. Empiirinen tutkimus oli normatiivinen case-tutkimus, jossa tarkasteltiin kahdessa toimittaja-asiakassuhteessa noudatettuja hinnoittelu- ja alennuskäytäntöjä. Aineisto kerättiin haastattelemalla toimittajan myyntihenkilöitä, ja lisänä käytettiin yrityksen sisäistä materiaalia. Analyysin tulokset osoittivat nykyisissä käytännöissä joitakin kilpailuoikeudellisia ristiriitaisuuksia, ja näihin annettiin parannusehdotuksia.
Resumo:
Sardinia is the second largest island in the Mediterranean and, together with Corsica and nearby mainland areas, one of the top biodiversity hotspots in the region. The origin of Sardinia traces back to the opening of the western Mediterranean in the late Oligocene. This geological event and the subsequent Messinian Salinity Crisis and Pleistocene glacial cycles have had a major impact on local biodiversity. The Dysdera woodlouse hunter spiders are one of the most diverse ground-dweller groups in the Mediterranean. Here we describe the first two species of this genus endemic to Sardinia: Dysdera jana sp. n. and Dysdera shardana sp. n. The two species show contrasting allopatric distribution: D. jana sp. n. is a narrow endemic while D. shardana sp. n. is distributed throughout most of the island. A multi-gene DNA sequence phylogenetic analys based on mitochondrial and nuclear genes supports the close relationships of the new species to the type species of the genus Dysdera erythrina. Age estimates reject Oligocene origin of the new Dysdera species and identify the Messinian Salinity Crises as the most plausible period for the split between Sardinian endemics and their closest relatives. Phylogeographic analysis reveals deep genetic divergences and population structure in Dysdera shardana sp. n., suggesting that restriction to gene flow probably due to environmental factors could explain local speciation events. Taxonomy, phylogeny, DNA sequencing, Mediterranean biogeography, phylogeography
Resumo:
This paper discusses the levels of degradation of some co- and byproducts of the food chain intended for feed uses. As the first part of a research project, 'Feeding Fats Safety', financed by the sixth Framework Programme-EC, a total of 123 samples were collected from 10 European countries, corresponding to fat co- and byproducts such as animal fats, fish oils, acid oils from refining, recycled cooking oils, and other. Several composition and degradation parameters (moisture, acid value, diacylglycerols and monoacylglycerols, peroxides, secondary oxidation products, polymers of triacylglycerols, fatty acid composition, tocopherols, and tocotrienols) were evaluated. These findings led to the conclusion that some fat by- and coproducts, such as fish oils, lecithins, and acid oils, show poor, nonstandardized quality and that production processes need to be greatly improved. Conclusions are also put forward about the applicability and utility of each analytical parameter for characterization and quality control.
Resumo:
The main target of the study was to find ideas for maintenance and development of supplier relations in irregular business environment. The other aim was to find out the suppliers’ opinions concerning the case company and the relationship between the companies. The study was conducted by using both qualitative and quantitative research methods. A mail survey was used to find out supplier opinions and an interview to find out suppliers’ ideas for relationship maintenance and development. It was found out that the use of relational elements is essential in the relationship maintenance in an irregular environment. In development of supplier relations the company should make better use of its suppliers’ potential, assure better flow of information and utilize the possibilities of Supplier Relationship Management.
Resumo:
This thesis examines the supplier-buyer relationships in the Finnish electronics industry. The aim of the study was to increase understanding on the challenges that suppliers face in their relationship with the buyer. The research was conducted using qualitative methods because they allow more perspective for the research problem than quantitative methods would have. Choosing qualitative method also affected the selection of a research technique. Analysis of secondary data from written documents was chosen to give more perspective to a broad problem. The main findings of this research are that the relationships between supplier and buyer in electronics industry are challenging because supplier must understand and face three types of challenges. The challenges are: understanding the environment, choosing and implementing correct strategy and managing relationships. For the supplier it is important to understand the environment so it can adjust own strategy to fit to the environment. The supplier should also be careful not to be too dependent on the buyer.
Resumo:
BACKGROUND: Available methods to simulate nucleotide or amino acid data typically use Markov models to simulate each position independently. These approaches are not appropriate to assess the performance of combinatorial and probabilistic methods that look for coevolving positions in nucleotide or amino acid sequences. RESULTS: We have developed a web-based platform that gives a user-friendly access to two phylogenetic-based methods implementing the Coev model: the evaluation of coevolving scores and the simulation of coevolving positions. We have also extended the capabilities of the Coev model to allow for the generalization of the alphabet used in the Markov model, which can now analyse both nucleotide and amino acid data sets. The simulation of coevolving positions is novel and builds upon the developments of the Coev model. It allows user to simulate pairs of dependent nucleotide or amino acid positions. CONCLUSIONS: The main focus of our paper is the new simulation method we present for coevolving positions. The implementation of this method is embedded within the web platform Coev-web that is freely accessible at http://coev.vital-it.ch/, and was tested in most modern web browsers.
Resumo:
Gram-negative bacteria represent a major group of pathogens that infect all eukaryotes from plants to mammals. Gram-negative microbe-associated molecular patterns include lipopolysaccharides and peptidoglycans, major immunostimulatory determinants across phyla. Recent advances have furthered our understanding of Gram-negative detection beyond the well-defined pattern recognition receptors such as TLR4. A B-type lectin receptor for LPS and Lysine-motif containing receptors for peptidoglycans were recently added to the plant arsenal. Caspases join the ranks of mammalian cytosolic immune detectors by binding LPS, and make TLR4 redundant for septic shock. Fascinating bacterial evasion mechanisms lure the host into tolerance or promote inter-bacterial competition. Our review aims to cover recent advances on bacterial messages and host decoding systems across phyla, and highlight evolutionarily recurrent strategies.
Resumo:
AimHigh intra-specific genetic diversity is necessary for species adaptation to novel environments under climate change, but species tracking suitable conditions are losing alleles through successive founder events during range shift. Here, we investigated the relationship between range shift since the Last Glacial Maximum (LGM) and extant population genetic diversity across multiple plant species to understand variability in species responses. LocationThe circumpolar Arctic and northern temperate alpine ranges. MethodsWe estimated the climatic niches of 30 cold-adapted plant species using range maps coupled with species distribution models and hindcasted species suitable areas to reconstructions of the mid-Holocene and LGM climates. We computed the species-specific migration distances from the species glacial refugia to their current distribution and correlated distances to extant genetic diversity in 1295 populations. Differential responses among species were related to life-history traits. ResultsWe found a negative association between inferred migration distances from refugia and genetic diversities in 25 species, but only 11 had statistically significant negative slopes. The relationships between inferred distance and population genetic diversity were steeper for insect-pollinated species than wind-pollinated species, but the difference among pollination system was marginally independent from phylogenetic autocorrelation. Main conclusionThe relationships between inferred migration distances and genetic diversities in 11 species, independent from current isolation, indicate that past range shifts were associated with a genetic bottleneck effect with an average of 21% loss of genetic diversity per 1000km(-1). In contrast, the absence of relationship in many species also indicates that the response is species specific and may be modulated by plant pollination strategies or result from more complex historical contingencies than those modelled here.
Resumo:
Peer-reviewed
Resumo:
Peer-reviewed
Resumo:
Marine microorganisms, including Aeromonas, are a source of compounds for drug development that have generated great expectations in the last decades. Aeromonas infections produce septicaemia, and ulcerative and haemorrhagic diseases in fish. Among the pathogenic factors associated with Aeromonas, the lipopolysaccharides (LPS), a surface glyconconjugate unique to Gram-negative bacteria consisting of lipid A (lipid anchor of the molecule), core oligosaccharide and O-specific polysaccharide (O antigen), are key elicitors of innate immune responses. The chemical structure of these three parts has been characterized in Aeromonas. Based on the high variability of repeated units of O-polysaccharides, a total of 97 O-serogroups have been described in Aeromonas species, of which four of them (O:11; O:16; O:18 and O:34) account for more than 60% of the septicemia cases. The core of LPS is subdivided into two regions, the inner (highly conserved) and the outer core. The inner core of Aeromonas LPS is characterized by the presence of 3-deoxy-D-manno-oct-2-ulosonic (ketodeoxyoctonic) acid (Kdo) and L-glycero-D-manno-Heptoses (L,D-Hep), which are linked to the outer core, characterized by the presence of Glc, GlcN, Gal, and GalNAc (in Aeromonas salmonicida), D,D-Hep (in Aeromonas salmonicida), and L,D-Hep (in Aeromonas hydrophila). The biological relevance of these differences in the distal part of the outer core among these species has not been fully assessed to date. The inner core is attached to the lipid A, a highly conserved structure that confers endotoxic properties to the LPS when the molecule is released in blood from lysed bacteria, thus inducing a major systemic inflammatory response known as septic or endotoxic shock. In Aeromonas salmonicida subsp. salmonicida the Lipid A components contain three major lipid A molecules, differing in acylation patterns corresponding to tetra-, penta- and hexaacylated lipid A species and comprising of 4′-monophosphorylated β-2-amino-2-deoxy-D-glucopyranose-(1→6)-2-amino-2-deoxy-D-glucopyranose disaccharide. In the present review, we discuss the structure-activity relationships of Aeromonas LPS, focusing on its role in bacterial pathogenesis and its possible applications.