952 resultados para Because I tell a joke or two
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r1955, Boston.
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Coumarins are special metabolites well distributed in the Angiospermae, either in Monocotyledoneae or Dicotyledoneae. Simple coumarins, the most widespread type, is found in all coumarin-producing families, such as: Apiaceae, Rutaceae, Asteraceae, Fabaceae, Oleaceae, Moraceae e Thymelaeaceae. The other types, linear- and angular furanocoumarins, linear- and angular pyranocoumarins, lignocoumarins, bis- and triscoumarins, are of more restricted circumscription. Among the families with occurrence numbers (NO) > 100, the more advanced ones are specialized in the production of only one or two coumarin types, while the primitive families are very well diversified in types. Calculations of percentual numbers of occurrence (%NO) show relevant meaning of coumarin-types in the taxonomic positioning of the producing taxa.
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A synthesis of artificial sweetener dulcin starting from nitrobenzene was elaborated for undergraduate organic laboratory course. Paracetamol and phenacetin, both physiologically active analgesic compounds, were also prepared as intermediates. Besides a large scope of discussion subjects related with organic synthesis, interesting lectures about analgesics and sweeteners may also be performed in this project. The advantage of this project is the adaptability according to the conditions offered by the course, i.e., convenience and/or availability of time and reagents.
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Research on limnology in southern Europe had achieved a notable presence in the international arena before the onset of the current dramatic cuts in public investment in science. We assessed the limnological research published in peer-reviewed journals by Spanish and Portuguese (i.e., Iberian) researchers during the decade prior to the economic recession (2000 to 2009). The Thompson Reuters Web of Knowledge database was used to retrieve all publications on limnology authored by researchers affiliated with Spanish or Portuguese institutions independently of the geographical setting of the study. The publishing pattern was characterised in terms of authors, journals, and citation statistics. In addition, a thematic characterisation of the research was performed by a manual assignation of several categorical descriptors combined with a blind word count analysis. Iberian researchers produced an annual mean of 278 papers on limnology. Papers were published in journals that had impact factors ranging from 0.1 to 31.4, with a mean of 2.0. Based on citations, the impact of the Iberian limnological research was not due to a few highly cited papers but rather to a wide number of publications; each paper received a mean of 8 citations. The Iberian limnological research involved up to 5460 researchers, with a mean of 4.3 authors per paper. The research largely focused on fluvial systems, with 47 % of total publications (2778) devoted to these ecosystems. There was a dominant focus on local, within-system aspects of study sites and the research was mostly restricted to the Iberian Peninsula; larger spatial scales of analysis (i.e., landscape, regional, or global) tended to be overlooked. Iberian research addressed fundamental (75 %) rather than applied (17 %) or methodological (5 %) questions and was vastly dominated by observational approaches (75 %). Interestingly, Iberian limnological research increased its scientific productivity during the analysed decade at a higher rate than its international counterpart (increase of 119 %). Overall, Iberian research on limnology appeared to be in good health during the analysed decade. Certain areas have been more studied than others, which opens opportunities to develop new research.
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Human papillomavirus (HPV) infections in mothers are important to consider since pregnancy may affect the outcome of the infection and the mother may transmit HPV to the child. This thesis is part of the 3-year Finnish Family HPV Study on HPV infection dynamics within 329 families. The presence of maternal HPV antibodies and HPV DNA in placenta, umbilical cord blood and breast milk was examined. In addition, genital and oral HR-HPV carriage was studied among mothers with one or two pregnancies. At enrollment, seropositivity to HPV 6, 11, 16, 18 and 45 was recorded in 53 %, 21 %, 35 %, 21 % and 9 % of the mothers, respectively. Age at sexual debut, number of sexual partners, a history of genital warts and antibodies to LR/HR-HPV predicted HR/LR-HPV-seropositivity. During follow-up 27 %, 14 %, 17 %, 17 % and 7 % of the mothers seroconverted to the tested HPV-types, respectively. Decay of HPV-antibodies was rare. The mother’s new pregnancy was of minor impact in the outcome of oral and cervical HR-HPV infections. HPV-DNA was present in 4.2 % and 3.5 % of the placentas and umbilical cord blood samples, and in 4.5 % and 19.7 % of the breast milk samples collected at day 3 and month 2 postpartum, respectively. HPV-positivity in placenta/cord blood was related to a history of abnormal pap-smears or genital warts, and raised the risk of the neonate being HPV-positive at birth. The mode of delivery did not predict the HPVstatus of neonate, placenta, or cord blood. HPV DNA in breast milk was associated with oral HPV status of the father, but not with HPV status of the neonate. The results indicate that exposure to HPV is common and that part of the exposure might take place already early in life. Contrary to the common claim, pregnancy is not a risk factor for HPV.
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Positron emission tomography (PET) studies on healthy individuals have revealed a marked interindividual variability in striatal dopamine D2 receptor density that can be partly accounted for by genetic factors. The examination of the extrastriatal lowdensity D2 receptor populations has been impeded by the lack of suitable tracers. However, the quantification of these D2 receptor populations is now feasible with recently developed PET radioligands. The objective of this thesis was to study brain neurobiological correlates of common functional genetic variants residing in candidate genes relevant for D2 receptor functioning. For this purpose, healthy subjects were studied with PET imaging using [11C]raclopride and [11C]FLB457 as radioligands. The candidate genes examined in this work were the human D2 receptor gene (<i>DRD2i>) and the catechol-Omethyltransferase gene (<i>COMTi>). The region-specific genotypic influences were explored by comparing D2 receptor binding properties in the striatum, the cortex and the thalamus. As an additional study objective, the relationship between cortical D2 receptor density and a cognitive phenotype i.e. verbal memory and learning was assessed. The main finding of this study was that <i>DRD2i> C957T genotype altered markedly D2 receptor density in the cortex and the thalamus whereas in the striatum the C957T genotype affected D2 receptor affinity, but not density. Furthermore, the A1 allele of the <i>DRD2i>-related TaqIA polymorphism showed increased cortical and thalamic D2 receptor density, but had the opposite effect on striatal D2 receptor density. The <i>DRD2i> –141C Ins/Del or the <i>COMTi> Val158Met genotypes did not change D2 receptor binding properties. Finally, unlike previously reported, cortical D2 receptor density did not show any significant correlation with verbal memory function. The results of this study suggest that the C957T and the TaqIA genotypes have region-specific neurobiological correlates in brain dopamine D2 receptor availability <i>in vivoi>. The biological mechanisms underlying these findings are unclear, but they may be related to the region-specific regulation of dopamine neurotranssion, gene/receptor expression and epigenesis. These findings contribute to the understanding of the genetic regulation of dopamine and D2 receptor-related brain functions <i>in vivoi> in man. In addition, the results provide potentially useful endophenotypes for genetic research on psychiatric and neurological disorders.
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This work investigates the adsorption of Alizarin, Eriochrome Blue Black R and Fluorescein using chitosan, goethite and magnetite as adsorbents. For Alizarin, the best adsorbent is chitosan with a Langmuir parameter of 15.8 mmol dye/g adsorbent. For Eriochrome Blue Black R only 1.94 mmol dye/g chitosan is adsorbed. Langmuir parameters for the Alizarin adsorption on both iron oxides display one or two orders of magnitude lower than for chitosan and two orders of magnitude lower in the case of Eriochrome Blue Black R. Fluorescein does not adsorb in appreciable amounts on chitosan and it presents the lower affinity on the iron oxides.
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Molecular modeling enables the students to visualize the abstract relationships underlying theoretical concepts that explain experimental data on the molecular and atomic levels. With this aim we used the free software "Arguslab 4.0.1" (semi-empirical method) to study the reaction of 1-chloropropane with ethoxide in solution, known to lead to methyl propyl ether, through the S N2 mechanism, and propene, through the E2 mechanism. This tool allows users to calculate some properties (i. e. heat formation or electric charges) and to produce 3D images (molecular geometry, electrostatic potential surface, etc.) that render the comprehension of the factors underlying the reaction's progress, which are related to the structure of the reagents, and the process kinetic clearer and easier to understand by the students
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This work presents the results of a study on the hydration of pastes containing calcium hydroxide and either rice husk ash (RHA) or sugar cane bagasse ash (SCBA) in various initial CaO/SiO2 molar ratios. The products of the reactions were characterized by thermal analyses X-ray diffraction, and scanning electron microscopy. In the case of the RHA pastes, the product was composed of CaO-SiO2-H2O (type I C-S-H) or CaO-SiO2-H2O (type II C-S-H) according to the CaO/SiO2 ratio of the mixture. In contrast, in the case of the SBCA pastes, the product was composed primarily of CaO-SiO2-H2O that differed from both the previous types; the product also contained inclusions of calcium aluminate hydrates.
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Juutalaisen filosofin Emmanuel Levinasin (1906-1995) ajattelusta käydyn keskustelun valossa ei ole itsestään selvää, että hänen etiikkansa on historiallista. Tutkielmassa etiikan historiallisuus perustellaan ja ymmärretään kolmesta näkökulmasta: ensiksi etiikan elämänhistoriallisena tulkintana, seuraavaksi etiikkaan sisältyvänä historianfilosofiana ja lopuksi lukion historian oppikirjojen eettisyyden tarkasteluna. Työn dispositio on sen keskeisimpiä tuloksia. Elämänhistoriasta liikkeelle lähtevä tulkinta paljastaa, että sekä Levinasin omat kokemukset holokaustista että juutalaisen muistamisen pitkä perinne motivoivat häntä käymään ylihistoriallista historianfilosofista keskustelua. Edelleen hänen ajattelunsa vaatii tämän keskustelun tulosten soveltamista käytännön elämään ja tutkimukseen, myös historiankirjoitukseen. Keskeisin lähde Levinasin tuotannossa on <i>Otherwise than Being or Beyond Essencei>. Myös teokset <i>Totality and Infinityi> ja, juutalaisuuden osalta, <i>Difficult Freedomi> ovat useiden tulkintojen pohjalla. Levinasin ajatteluun keskittyvässä kotimaisessa tutkimuskirjallisuudessa tärkeä keskustelukumppani on Jukka Hankamäki ja ulkomaisessa mm. Aadrian Peperzak ja Rudi Visker. Historianteoreettista keskustelua käydään ennen kaikkea Kari Immosen, Jorma Kalelan ja Edith Wyschogrodin kanssa. Tutkielman päättävän tapaustutkimuksen aineistopohjan muodostavat kahdeksan tutkielman kirjoitushetkellä opetuskäytössä olevaa lukion historian oppikirjaa. Tutkielma keskittyy Levinasin filosofiaan kuuluvaan ylihistoriallisuuden ja historiallisuuden jännitteeseen. Ylihistoriallisuus tulkitaan myös inhimilliseksi toiseudeksi ja historiallisuus kulttuuriseksi toiseudeksi. Levinasin mukaan kumpiakin tarvitaan eettisen historiankirjoituksen onnistumiseksi, mutta kulttuurinen toiseus uhkaa usein tukahduttaa inhimillisen toiseuden. Tapaustutkimuksessa päädytään siihen, että lukion historian oppikirjoissa kulttuurinen toiseus ja sille läheinen historian läsnäolo todella uhkaavat peittää alleen menneisyyden ihmisten kuolevaisuuden ja korvaamattomuuden. Menneisyyden ihmisten poissaolon vahvempi huomioiminen historian läsnäolon rinnalla voisi helpottaa etiikan käsittelyn ongelmia, jotka ovat selvästi havaittavissa niin opetussuunnitelman perusteissa kuin oppikirjoissakin. Tutkielmassa myös nostetaan oppikirjoista esimerkkejä, joissa on toimittu onnistuneesti juuri näin. Sama suositus esitetään myös kulttuurihistorian tutkimukselle ja historianteoreettiselle keskustelulle, jossa historian läsnäolon pohdinta ylikorostuu.
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Työn tavoitteena oli laatia Mäntsälän Sähkö Oy:n jakeluverkon kehittämissuunnitelma vuodelle 2020. Työn laadinta aloitettiin selvittämällä verkon nykytila ja käyttövarmuus korvaustilanteissa. Tämän jälkeen työssä paikannettiin alueet, joissa korvattavuuden parantaminen tai kuormituksien kasvaminen tulevaisuudessa edellyttää mittavia investointeja jakeluverkon käyttövarmuuden takaamiseksi. Työssä tarkastellaan yksityiskohtaisemmin Järvelän alueen käyttövarmuuden kehittämistä ja Hennan alueen kuormituksen kasvuun varautumista. Järvelän alueen käyttövarmuuden parantaminen edellyttää joko uutta sähköasemainvestointia tai 110 kV johdon rakentamista. Hennan alueen kuormituksen kasvu edellyttää, alueen kuormituksista riippuen, joko yhtä tai kahta uutta sähköasemainvestointia.
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The complexes of 2,6-dimethoxybenzoic acid anion with ions of Co(II), Ni(II), and Cu(II) have been synthesized as polycrystalline solids, and characterized by elemental analysis, spectroscopy, magnetic studies, and also by X-ray diffraction and thermogravimetric measurements. The analysed complexes have following colours: pink for Co(II), green for Ni(II), and blue for Cu(II) compounds. The carboxylate group binds as monodentate, and bidentate bridging and chelating ligands. On heating in air to 1173 K the complexes decompose in four, three or two steps. At first, they dehydrate in one or two steps to anhydrous salts, that next decompose to oxides of the respective metals. The solubility of the investigated dimethoxybenzoates in water at 293 K is of the order of 10-2 mol/dm3. Their magnetic moments were determined in the temperature range of 76-303 K. The results reveal the compounds of Co(II) and Ni(II) to be high-spin complexes and that of Cu(II) to form dimer.
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Drug-drug interactions (DDIs) comprise an important cause of adverse drug reactions leading to excess hospitalizations. Drug metabolism is catalyzed by 75% by cytochrome P450 (CYP) enzymes and thus they are often involved in pharmacokinetic DDIs. In general, DDIs are studied in randomized controlled clinical trials in selected study populations. The overall aim of the present studies was to perform observational pharmacoepidemiological surveys on CYP-mediated DDIs in diseases important at the population level. The prevalence of co-administrations of four prodrugs (losartan, codeine, tramadol, and clopidogrel), three sulphonylureas (glibenclamide, glimepiride, and glipizide), or two statins (lovastatin and simvastatin) with well established agents altering CYP activity, as well as of statins with fibrates, was studied in Finland utilizing data from a university hospital medication database (inpatients) and the National Prescription Register of the Social Insurance Institution of Finland, Kela (outpatients). Clinical consequences of potential DDIs were estimated by reviewing laboratory data, and information from hospital care and cause-of-death registers. Concomitant use of study substrates with interacting medication was detected in up to one fifth of patients in both hospital and community settings. Potential CYP3A4 interactions in statin users did not manifest in clear adverse laboratory values but pharmacodynamic DDIs between statins and fibrates predisposed patients to muscular toxicity. Sulphonylurea DDIs with CYP2C9 inhibitors increased the risk of hypoglycaemia. CYP3A4 inhibitor use with clopidogrel was not associated with significant changes in mortality but non-fatal thrombosis and haemorrhage complications were seen less often in this group. Concomitant administration of atorvastatin with clopidogrel moderately attenuated the antithrombotic effect by clopidogrel. The overall mortality was increased in CYP3A4 inducer and clopidogrel co-users. Atorvastatin used concomitantly with prodrug clopidogrel seems to be beneficial in terms of total and LDL cholesterol concentrations, and overall mortality compared with clopidogrel use without interacting medication. In conclusion, CYP-mediated DDIs are a common and often unrecognized consequence of irrational drug prescribing.
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In this Thesis I discuss the exact dynamics of simple non-Markovian systems. I focus on fundamental questions at the core of non-Markovian theory and investigate the dynamics of quantum correlations under non-Markovian decoherence. In the first context I present the connection between two different non-Markovian approaches, and compare two distinct definitions of non-Markovianity. The general aim is to characterize in exemplary cases which part of the environment is responsible for the feedback of information typical of non- Markovian dynamics. I also show how such a feedback of information is not always described by certain types of master equations commonly used to tackle non-Markovian dynamics. In the second context I characterize the dynamics of two qubits in a common non-Markovian reservoir, and introduce a new dynamical effect in a wellknown model, i.e., two qubits under depolarizing channels. In the first model the exact solution of the dynamics is found, and the entanglement behavior is extensively studied. The non-Markovianity of the reservoir and reservoirmediated-interaction between the qubits cause non-trivial dynamical features. The dynamical interplay between different types of correlations is also investigated. In the second model the study of quantum and classical correlations demonstrates the existence of a new effect: the sudden transition between classical and quantum decoherence. This phenomenon involves the complete preservation of the initial quantum correlations for long intervals of time of the order of the relaxation time of the system.
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Hajautettujen ryhmien käyttöä ja virtuaalista yhteistyötä on tutkittu runsaasti. Useat tutkimukset ovat kuvanneet globaalien tiimien toimintaa ja keskittyneet yritysmaailmaan. Puolustusvoimissa on tutkittu virtuaalisen työskentelyn hyödyntämistä, mutta tutkimukset painottuvat opiskelumenetelmiin. Työn tavoitteena oli selvittää virtuaalisen yhteistyön edellytyksiä ja sen tarjoamia mahdollisuuksia maavoimien tutkimus- ja kehittämistoiminnassa. Kirjallisuuskatsauksessa tarkasteltiin hajautetun organisaation rakennetta ja johtamista, virtuaalisen yhteistyön edellytyksiä sekä eri viestintävälineiden soveltuvuutta erilaisiin tehtäviin. Empiirinen osuus toteutettiin haastattelututkimuksena kolmessa fokusryhmässä laadullisen analyysin menetelmin. Tutkimuksessa saatiin selville, että rakenteelliset ja tekniset edellytykset virtuaalisen yhteistyön hyödyntämiselle ovat olemassa, mutta organisaation sisäinen vuoropuhelu ei toimi. Tämä osin estää virtuaalisen yhteistyön, koska työryhmiä ei muodostu tai ryhmillä ei ole selkeitä tavoitteita. T&K -toiminnan prosessi on kuvattu varsin tarkasti, mutta prosessi ei toimi kuvatulla tavalla. Tutkimus- ja kehittämistoiminnan ohjaus ei onnistu, mikä johtaa epäselvyyksiin resurssien käytön suunnittelussa. Yhtenä tekijänä suunnittelun epäonnistumisessa on projektijohtamisen ja projektinhallinnan osaamattomuus.