980 resultados para karyotype diversification
Resumo:
This PhD study aims to exploit the rich archive provided by the Miocene mollusc fauna of the Pebas Formation and other inland Miocene Amazonian formations to reconstruct landscape evolution and biotic development in lowland Amazonia during the Neogene. Over 160 samples from more than 70 Pebas Formation outcrops mostly collected by the author were processed for this study. Additional samples were collected in Andean areas of Colombia and Venezuela and further material from other northwestern South American basins was studied in museums. Pebas Formation samples and well log data made available by Occidental Peru from three wells in the Marañon Basin in Peru were also investigated. During this study four genera and 74 species from the Pebas Formation have been described and a further 13 species have been introduced in open nomenclature, and several species were reported for the first time. The number of mollusc species attributed to the Pebas fauna has increased from around 50 to 156. The Pebas fauna is characterised as aquatic, endemic and extinct, and is a typical representative of a long-lived lake fauna. Fluvial taxa are not common, (marginal) marine taxa are rare. An additional molluscan fauna from the Miocene Solimões Formation of Brazil, containing 13 fresh water species was also described. The newly documented fauna was used to improve biostratigraphic framework of Miocene Amazonian deposits. Twelve mollusc zones were introduced, the upper eleven of which cover a time interval of approximately seven million years covered previously by only three pollen zones. An age model calculated for the borehole data indicates that the Pebas Formation was deposited between c. 24 and 11 Ma. The areal distribution of the outcropping mollusc zones uncovered a broad dome structure, termed here the Iquitos-Araracuara anteclise in the study area. The structure appears to have influenced river courses and also contributed to edaphic heterogeneity that may have been in part responsible for the current high biodiversity in the study area. The Pebas system was a huge system (> one million km2) dominated by relatively shallow lakes, but also containing swamps and rivers. The system was fed by rivers draining the emergent Andes in the west and lowlands and cratons to the east. The Pebas system was located at sea level and was open to marine settings through a northern portal running through the Llanos Basin and East Venezuela Basin towards the Caribbean. Cyclical baselevel changes possibly related to Mylankhovitch cycles, have been documented in depositional sequences of the Pebas Formation. The composition of the Pebasian mollusc fauna implies that the system was mostly a fresh water system. Such an interpretation is matched by strontium isotope ratios as well as very negative δ18O ratios found in the shells, but is at odds with oligohaline and mesohaline ichnofacies found in the same strata. The mollusc fauna of the Pebas Formation diversified through most of the existence of the lake system. The diversification was mostly the result of in-situ cladogenesis. The success of some of the Pebasian endemic clades is explained by adaptation to fresh water, low oxygen, common unconsolidated lake bottoms (soup grounds) as well as high predation intensity. Maximum diversity was reached at the base of the late Middle to early Late Miocene Grimsdalea pollen zone, some 13 Ma. At the time some 85 species co-occurred, 67 of which are considered as Pebasian endemics. A subsequent drop in species richness coincides with indications of elevated salinities, although a causal relation still needs to be established. Apparently the Pebas fauna went (almost) entirely extinct with the replacement of the lake system into a fluvio-tidal system during the Early Late Miocene, some 11 Ma.
Resumo:
The genome of the bladderwort Utricularia gibba provides an unparalleled opportunity to uncover the adaptive landscape of an aquatic carnivorous plant with unique phenotypic features such as absence of roots, development of water-filled suction bladders, and a highly ramified branching pattern. Despite its tiny size, the U. gibba genome accommodates approximately as many genes as other plant genomes. To examine the relationship between the compactness of its genome and gene turnover, we compared the U. gibba genome with that of four other eudicot species, defining a total of 17,324 gene families (orthogroups). These families were further classified as either 1) lineage-specific expanded/contracted or 2) stable in size. The U. gibba-expanded families are generically related to three main phenotypic features: 1) trap physiology, 2) key plant morphogenetic/developmental pathways, and 3) response to environmental stimuli, including adaptations to life in aquatic environments. Further scans for signatures of protein functional specialization permitted identification of seven candidate genes with amino acid changes putatively fixed by positive Darwinian selection in the U. gibba lineage. The Arabidopsis orthologs of these genes (AXR, UMAMIT41, IGS, TAR2, SOL1, DEG9, and DEG10) are involved in diverse plant biological functions potentially relevant for U. gibba phenotypic diversification, including 1) auxin metabolism and signal transduction, 2) flowering induction and floral meristem transition, 3) root development, and 4) peptidases. Taken together, our results suggest numerous candidate genes and gene families as interesting targets for further experimental confirmation of their functional and adaptive roles in the U. gibba's unique lifestyle and highly specialized body plan.
Resumo:
Last two decades have seen a rapid change in the global economic and financial situation; the economic conditions in many small and large underdeveloped countries started to improve and they became recognized as emerging markets. This led to growth in the amounts of global investments in these countries, partly spurred by expectations of higher returns, favorable risk-return opportunities, and better diversification alternatives to global investors. This process, however, has not been without problems and it has emphasized the need for more information on these markets. In particular, the liberalization of financial markets around the world, globalization of trade and companies, recent formation of economic and regional blocks, and the rapid development of underdeveloped countries during the last two decades have brought a major challenge to the financial world and researchers alike. This doctoral dissertation studies one of the largest emerging markets, namely Russia. The motivation why the Russian equity market is worth investigating includes, among other factors, its sheer size, rapid and robust economic growth since the turn of the millennium, future prospect for international investors, and a number of important major financial reforms implemented since the early 1990s. Another interesting feature of the Russian economy, which gives motivation to study Russian market, is Russia’s 1998 financial crisis, considered as one of the worst crisis in recent times, affecting both developed and developing economies. Therefore, special attention has been paid to Russia’s 1998 financial crisis throughout this dissertation. This thesis covers the period from the birth of the modern Russian financial markets to the present day, Special attention is given to the international linkage and the 1998 financial crisis. This study first identifies the risks associated with Russian market and then deals with their pricing issues. Finally some insights about portfolio construction within Russian market are presented. The first research paper of this dissertation considers the linkage of the Russian equity market to the world equity market by examining the international transmission of the Russia’s 1998 financial crisis utilizing the GARCH-BEKK model proposed by Engle and Kroner. Empirical results shows evidence of direct linkage between the Russian equity market and the world market both in regards of returns and volatility. However, the weakness of the linkage suggests that the Russian equity market was only partially integrated into the world market, even though the contagion can be clearly seen during the time of the crisis period. The second and the third paper, co-authored with Mika Vaihekoski, investigate whether global, local and currency risks are priced in the Russian stock market from a US investors’ point of view. Furthermore, the dynamics of these sources of risk are studied, i.e., whether the prices of the global and local risk factors are constant or time-varying over time. We utilize the multivariate GARCH-M framework of De Santis and Gérard (1998). Similar to them we find price of global market risk to be time-varying. Currency risk also found to be priced and highly time varying in the Russian market. Moreover, our results suggest that the Russian market is partially segmented and local risk is also priced in the market. The model also implies that the biggest impact on the US market risk premium is coming from the world risk component whereas the Russian risk premium is on average caused mostly by the local and currency components. The purpose of the fourth paper is to look at the relationship between the stock and the bond market of Russia. The objective is to examine whether the correlations between two classes of assets are time varying by using multivariate conditional volatility models. The Constant Conditional Correlation model by Bollerslev (1990), the Dynamic Conditional Correlation model by Engle (2002), and an asymmetric version of the Dynamic Conditional Correlation model by Cappiello et al. (2006) are used in the analysis. The empirical results do not support the assumption of constant conditional correlation and there was clear evidence of time varying correlations between the Russian stocks and bond market and both asset markets exhibit positive asymmetries. The implications of the results in this dissertation are useful for both companies and international investors who are interested in investing in Russia. Our results give useful insights to those involved in minimising or managing financial risk exposures, such as, portfolio managers, international investors, risk analysts and financial researchers. When portfolio managers aim to optimize the risk-return relationship, the results indicate that at least in the case of Russia, one should account for the local market as well as currency risk when calculating the key inputs for the optimization. In addition, the pricing of exchange rate risk implies that exchange rate exposure is partly non-diversifiable and investors are compensated for bearing the risk. Likewise, international transmission of stock market volatility can profoundly influence corporate capital budgeting decisions, investors’ investment decisions, and other business cycle variables. Finally, the weak integration of the Russian market and low correlations between Russian stock and bond market offers good opportunities to the international investors to diversify their portfolios.
Resumo:
Tässä tutkielmassa tarkastellaan suomalaisen sijoitusportfolion hajauttamista asuinkiinteistöihin. Tutkielman tavoitteena on selvittää, pystyykö hajauttamisella tehostamaan portfoliota sekä tutkia kaupungin ja kokoluokan merkitystä kiinteistöihin hajauttamisessa. Tutkimusaineisto koostuu Suomen osakemarkkinoita kuvaavista toimialaindeksistä sekä asuinkiinteistöindekseistä. Asuinkiinteistöt ovat jaoteltu sekä kaupungeittain että kokoluokittain. Tutkimusaineisto on aikaperiodilta 1988Q3-2008Q3. Tutkimustulosten mukaan kiinteistöihin hajauttamisella voidaan tehostaa portfoliota. Varsinkin pienemmillä tuottotasoilla kiinteistöihin sijoitetaan merkittävästi. Korkeammilla tuottovaatimuksilla kiinteistösijoitus ei tuonut lisäarvoa portfolion hajautukseen.
Resumo:
Tutkielman tavoitteena oli selvittää, kuinka muutosvaiheessa oleva elektroniikkateollisuuden ala vaikuttaa siinä mukana olevien pienten ja keskisuurten sopimusvalmistaja yritysten tulevaisuuden kasvustrategioihin Tutkielmassa päädyttiin tarkastelemaan seuraavia kasvustrategioita: markkinapenetraatio, tuotekehitys yhdessä asiakkaan kanssa, markkinakehitys ja diversifikaatio. Tutkielmassa määriteltiin myös kasvustrategioihin yleisesti vaikuttavat tekijät, joita käsiteltiin empiriassa pk-sopimusvalmistajan näkökulmasta. Esitettyjä kasvustrategioita peilattiin elektroniikkateollisuuden tulevaisuuden näkymiin skenaariotyöskentelyä hyödyntäen. Erityisesti yrityksen sopimusvalmistajaroolin todettiin vaikuttavan niin kasvustrategioihin kuin valittua strategiaa toteuttaviin kasvukeinoihin. Tutkimuksessa käytettiin laadullista eli kvalitatiivista tutkimusotetta. Tutkimusmenetelmäksi puolestaan valittiin tapaus eli case-tutkimus. Kohdeyrityksen avulla pyrittiin luomaan syvempää ymmärrystä pk-sopimusvalmistajan resursseista, kyvykkyyksistä ja haasteista.
Resumo:
Inversors però, principalment professionals de l'àmbit agrari, per tal de buscar una diversificació de l'activitat agrícola i ramadera que desenvolupen a les seves finques, sobretot joves emprenedors, poden estar interessats en produccions alternatives com la producció d'ànecs per a foie-gras, per tal de complementar la seva renda agrària. Actualment cal augmentar la competitivitat de les finques agrícoles per tal que aquestes siguin econòmicament viables. L’objectiu de l'estudi és determinar la viabilitat econòmica d’una explotació ramadera d’ànecs per a la producció de foie-gras, en el terme municipal de Fontanals de Cerdanya, analitzant les diverses alternatives en quant a dimensionament i disseny de les instal·lacions, segons el cicle productiu de l’animal. L'alternativa escollida per realitzar l'estudi es la de semi-integració (cria, engreix i embocat), de règim semi-intensiu (durant l'etapa de l'engreix), amb animals mascles de la raça híbrida Mulard. Les instal·lacions tindran una capacitat de 6.500 animals, amb lots de 250 caps. Aquest dimensionament permet, durant la fase d'embocat, en la qual es requereix més dedicació, que la demanda de mà d'obra pugui ser satisfeta per un únic treballador. La principal conclusió que es pot extreure de l'estudi és que la inversió projectada és massa elevada i que aquesta econòmicament no és viable o rendible, ja que la despesa és massa elevada. Es mouen uns fluxos de caixa molt elevats i el marge comercial és molt reduït. Únicament si l'objectiu del promotor és obtenir una remuneració per la seva feina, sempre i quan és produeixi un augment del preu actual de la carn i una disminució del preu del pinso, es podria recomanar que es portés a terme la implantació de l'explotació, intentant, però, reduir la despesa d'execució de construccions i instal·lacions.
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The natural rubber is a strategic material which can not be replaced by synthetic rubber in many technological applications. Brazil is a rubber importer, but new techniques of cultivation, breeding and diversification of producing species can reverse this situation. One of the best ways to add value to this commodity is nanotechnology. The production of nanocomposites is already a reality and shows that the sustainable use of this natural resource can lead to new products and boost the national agribusiness setting labor-qualified in the field.
Resumo:
The AIDS epidemy has spread out and led to the diversification on the research for new antiviral drugs. Natural products, especially those derived from plants, are well-recognized as excellent sources of new drugs. Several of them have inhibitory activity against HIV replication, and some have been already clinically tested, with favorable results. This review presents the biochemical basis of the viral cycle and the research up to date on the identification, determination of the mechanism of biological action together with the therapeutical potential of plants-derived natural products, in the inhibition of HIV.
Resumo:
The main objective of this work was to evaluate the diversification of sorghum (Sorghum bicolor) populations as a way to manage resistance to the sorghum anthracnose fungus Colletotrichum graminicola. A total of 18 three-way hybrids were obtained by crossing six single cross male-sterile F1 hybrids, derived by crossing A (non restorer sterile cytoplasm) and B (non restorer normal cytoplasm) lines, with three fertile R (restorer) lines, previously evaluated for their differential reaction to the pathogen. Variation in the level of resistance was observed, as indicated by the values of the area under the disease progress curve (AUDPC) obtained for each hybrid. Lines contributed differently to the level of resistance of each hybrid. All hybrids in which CMSXS169R was the male progenitor were classified as highly resistant. Some hybrids had a level of resistance superior to the maximum levels of each line component individually.
Resumo:
Tutkimuksessa selviteltiin osaamiskäsityksiä ja niiden mahdollisia eroja tukiorganisaation eri johtamistasoilla. Tutkimus on kvalitatiivinen ja aineisto kerättiin teemahaastatteluilla. Varsinaisen tutkimuskysymyksen lisäksi selvitettiin haastateltavien mielipiteitä erilaisista osaamiseen ja osaamisen johtamiseen vaikuttavista tekijöistä ja niiden tilasta kohdeorganisaatiossa. Näin saatiin selville käsityksiä mm. ulkopuolisen osaamisen roolista, organisaation strategiasta sekä tiedon hallintaan liittyvistä toimintatavoista. Tutkimuksessa käytetty teoreettinen kehys kuvaa organisaation osaamisen johtamista kokonaisvaltaisesti. Tässä kehyksessä osaamisen johtamisen eri tasojen ja moodien on toimittava jotta organisaatio voi saavuttaa asettamansa tavoitteet. Organisaation johdon on vastattava siitä, mitä tuotteita tai palveluita organisaatio tarjoaa ja miten resursseja kohdennetaan tavoitteiden saavuttamiseksi. Jos organisaation johdon käsityksissä organisaation osaamisista on eroja, voi seurauksena olla toiminnan eriytymistä ja tehotonta resurssien käyttöä. Haastatteluissa tärkeimpiä, strategisia osaamisia lähestyttiin tärkeimpien palveluiden kautta. Tulosten perusteella osaamiskäsityksissä ei ollut eroja, jotka olisivat tuottaneet suuria ongelmia toimintaan. Osaamiskäsitykset tukiorganisaatiossa olivat samansuuntaisia. Vaikka organisaatiolla ei koettu olevan selkeää strategiaa, osaamista ja resursseja johdettiin ja kehitettiin tavoitteiden saavuttamiseksi. Myös osaamisen tunnistamisen, vanhentuneesta osaamisesta luopumisen ja organisaation hallitseman tiedon tallentamisesta ja jakamisesta esiin tulleet näkemykset olivat samankaltaisia. Suurimmat erot mielipiteissä koskivat ulkoisen osaamisen hankkimisperusteita ja hyödyntämistä.
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Tutkielman tavoitteena on selvittää, kuinka suuria hajautushyötyjä sijoittajan on mahdollista saavuttaa Suomen osakemarkkinoilla lisäämällä eri yhtiöiden osakkeita sijoitusportfolioonsa. Lisäksi tutkitaan, minkälaisia hajautushyötyjä OMXH25 -indeksiosuusrahasto tarjoaa markkinaportfolioon verrattuna. Tutkimusaineisto on vuosilta 2007–2011. Tutkimuksen mukaan markkinariski Suomen osakemarkkinoilla on 29,59 prosenttia ja hajautettavissa olevan yritysriskin määrä on siten 70,41 prosenttia. Portfolion riski alenee nopeasti ensimmäisiä osakkeita lisättäessä, mutta hajautuksen vähenevän rajahyödyn takia yli kahdenkymmenen osakkeen portfolioilla riskin aleneminen on marginaalista. Viidellä osakkeella saavutetaan yli 80 prosenttia, kymmenellä osakkeella yli 90 prosenttia ja 18 osakkeella yli 95 prosenttia hajautushyödyistä. OMXH25 -indeksiosuusrahastolla saavutetaan merkittävät hajautushyödyt.
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The objective of the thesis is to examine the current state of risk management and to determine an appropriate risk management policy for commercial property derived risks in the Russian branch of a Finnish retail trade company. The employed research methodologies are comparative in-depth interviews and empirical value at risk analysis, including portfolio risk decomposition to determine the inter-currency characteristics. For a multinational retail trade company, the commercial property derived risks open up as a diverse combination of financial and non-financial risks with four distinctive interest groups. The research results indicate that geographical diversification across currency regimes provides diversification benefits. The Russian ruble is the most significant single risk component when considering the net investments outside the euro-zone. Decreasing the Russian ruble and Swedish krona exposures are the most effective methods to reduce translation derived risk. Exchange rate volatility varies over time according to idiosyncratic currency regime characteristics, and cost-effective risk management requires comprehensive analysis of the business environment. Profound and proactive risk management methods are found to be pivotal for companies with cross-border operations in order to succeed among international competitors.
Resumo:
Due to the different dynamics required for organizations to serve the emerging market which contains billions of people at the bottom of the pyramid (BOP) coupled with the increasing desire for organizations to grow and be more multinational, organizations need to continually innovate. However, the tendency for large and established companies to ignore the BOP market and rather focus on existing markets, gives an indication of the existence of a vulnerability that potentially disruptive innovations from the BOP will not be recognized in good time for a counter measure. This can be deduced from the fact that good management practice advocates that managers should learn and listen to their customers. Therefore majority of the large existing companies continually focus on their main customer/market with sustaining innovations which leaves aspiring new entrants with an underserved BOP market to experiment with. With the aid of research interviews and an agent-based model (ABM) simulation, this thesis examines the attributes of BOP innovations that can qualify them as disruptive and the possibilities of tangible disruptive innovations arising from the bottom of the pyramid and their underlying drivers. The thesis Furthermore, examines the associated impact of such innovations on the future sustainability of established large companies that are operating in the developed world, particularly those with a primary focus which is targeted towards the market at the top of the pyramid (TOP). Additionally, with the use of a scenario planning model, the research provides an evaluation of the possible evolution and potential sustainability impacts that could emerge, from the interplay of innovations at the two pyramidal market levels and the chosen market focus of organizations – TOP or BOP. Using four scenario quadrants, the thesis demonstrates the resulting possibilities from the interaction between the rate of innovations and the segment focused on by organizations with disruptive era characterizing the paradigm shift quadrant. Furthermore, a mathematical model and two theoretical propositions are developed for further research. As recommendations, the thesis also extends the ambidextrous organizational theory, business model innovation and portfolio diversification as plausible recommendations to limit a catastrophic impact, resulting from disruptive innovations.
Resumo:
Tämän tutkimuksen tavoitteena on selvittää onko kansainvälisen hajauttamisen hyöty heikentynyt globaalisti ajan kuluessa. Tutkimusongelmaan pyritään löytämään vastaus korrelaatioanalyysillä sekä Box M-testillä. Teoreettisena viitekehyksenä käytetään Markowitzin luomaa modernia portfolioteoriaa, kansainväliseen hajautukseen liittyvää kirjallisuutta sekä aiheesta aiemmin tehtyjä tutkimuksia. Empiirisenä tutkimusaineistona käytetään Thomson Datastreamin tuottamia kokonaistuottoindeksejä. Indeksit ovat yhdeksältä eri markkina-alueelta ja 30 eri maasta. Maat on jaoteltu 18 kehittyneeseen ja 12 kehittyvään maahan.kaikki tutkielmassa käytetyt tuottoaikasarjat ovat dollarimääräisiä. Tutkimusaineisto kattaa vuodet 1995-2009 sisältäen 783 viikottaista havaintoa, kullekin tuottoindeksille. Tutkimustulosten mukaan kansainvälisen hajauttamisen edut ovat suuremmat sijoitettaessa kehittyville markkinoille, kuin pelkästään kehittyneille markkinoille sijoitettaessa. Tutkimusperiodin alkupuolella kehittyvillä markkinoilla on ollut saatavissa huomattavasti enemmän hajautushyötyä, mutta suhteellinenhyöty suhteessa kehittyneisiin markkinoihin vähenee tultaessa lähemmäs nykyhetkeä. Korrelaatiot ovat nousseet koko ajanjaksolla, mutta on myös ollut osaperiodeja, jolloin korrelaatiokertoimet ovat laskeneet.
Resumo:
The aim of this study is to examine the level of stock market co-movement in the BRICS countries and three major industrialized countries (Japan, UK and USA). While analyzing the interdependence and integration of markets, two subsets are examined: before (2000 – 2007) and during the global financial crisis (2007-2011). Generally, interdependence across markets is likely to increase during a highly volatile period. This is problematic because if it were true, the main benefit of international diversification would be reduced at times when it is most needed. The results reveal the dominant role of the US financial markets over the examined time period. Empirical studies of this research paper indicate that cross-market linkages have become slightly stronger during the ongoing subprime crisis than before crisis. However, results also show that an investor may obtain some international diversification benefits by investing especially in the BRICS countries despite the fact of unstable economic condition and growing globalization.