931 resultados para Emission Tuning
Resumo:
Ectopic ACTH Cushing's syndrome (EAS) is often caused by neuroendocrine tumors (NETs) of lungs, pancreas, thymus, and other less frequent locations. Localizing the source of ACTH can be challenging. A 64-year-old man presented with rapidly progressing fatigue, muscular weakness, and dyspnea. He was in poor condition and showed facial redness, proximal amyotrophy, and bruises. Laboratory disclosed hypokalemia, metabolic alkalosis, and markedly elevated ACTH and cortisol levels. Pituitary was normal on magnetic resonance imaging (MRI), and bilateral inferior petrosal sinus blood sampling with corticotropin-releasing hormone stimulation showed no significant central-to-periphery gradient of ACTH. Head and neck, thoracic and abdominal computerized tomography (CT), MRI, somatostatin receptor scintigraphy (SSRS), and (18)F-deoxyglucose-positron emission tomography (FDG-PET) failed to identify the primary tumor. (18)F-dihydroxyphenylalanine (F-DOPA)-PET/CT unveiled a 20-mm nodule in the jejunum and a metastatic lymph node. Segmental jejunum resection showed two adjacent NETs, measuring 2.0 and 0.5 cm with a peritoneal metastasis. The largest tumor expressed ACTH in 30% of cells. Following surgery, after a transient adrenal insufficiency, ACTH and cortisol levels returned to normal values and remain normal over a follow-up of 26 months. Small mid-gut NETs are difficult to localize on CT or MRI, and require metabolic imaging. Owing to low mitotic activity, NETs are generally poor candidates for FDG-PET, whereas SSRS shows poor sensitivity in EAS due to intrinsically low tumor concentration of type-2 somatostatin receptors (SST2) or to receptor down regulation by excess cortisol. However, F-DOPA-PET, which is related to amine precursor uptake by NETs, has been reported to have high positive predictive value for occult EAS despite low sensitivity, and constitutes a useful alternative to more conventional methods of tumor localization. LEARNING POINTS: Uncontrolled high cortisol levels in EAS can be lethal if untreated.Surgical excision is the keystone of NETs treatment, thus tumor localization is crucial.Most cases of EAS are caused by NETs, which are located mainly in the lungs. However, small gut NETs are elusive to conventional imaging and require metabolic imaging for detection.FDG-PET, based on tumor high metabolic rate, may not detect NETs that have low mitotic activity. SSRS may also fail, due to absent or low concentration of SST2, which may be down regulated by excess cortisol.F-DOPA-PET, based on amine-precursor uptake, can be a useful method to localize the occult source of ACTH in EAS when other methods have failed.
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Ihmisen toiminnan vaikutus ilmakehään johtaa todennäköisesti ilmastonmuutoksiin. Eräs näistä muutoksista on maapallon keskilämpötilan nousu, joka aiheutuu kasvihuonekaasujen lisääntyneestä pitoisuudesta ilmakehässä. Vaikutusten vähentämiseksi on hiilidioksidipäästöjä vähennettävä. Kioton pöytäkirja asettaa allekirjoittaneille maille päästövelvoitteet. Euroopan unionin tulee vähentää kasvihuonekaasupäästöjään 8%:lla. Eräs vähennysmekanismeista on päästökauppa. Päästökauppa on sekä keino suojella ympäristöä että ympäristöpoliittinen instrumentti kasvihuonekaasupäästövähennysten kustannusten keventämiseksi. Päästökauppa ei suoranaisesti vähennä kasvihuonekaasupäästöjä, vaan tasaa niitä maiden ja laitosten välillä. Uusiutuvan energian käytön edistäminen sekä kansainvälisesti että kansallisesti johtaa suoriin kasvihuonekaasupäästöjen vähenemiseen. Euroopan unionin jäsenvaltiot ovat asettaneet kansalliset viitearvot uusituvan sähkön kulutukselle. Saavuttaakseen nämä viitearvot maiden tulee tukea uusiutuvia energialähteitä eri menetelmin kuten vihreillä sertifikaateilla. Päästökauppa ja kaupattavat vihreät sertifikaatit tulevat vaikuttamaan energiantuottajien liiketoimintaan. Työssä on tutkittu päästökaupan ja vihreiden sertifikaattien vaikutuksia Vattenfall Kaukolämpö Oy:n, Vattenfall Sähköntuotanto Oy:n ja Vamy Oy:n liiketoimintaan.
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We show that the quasifission paths predicted by the one-body dissipation dynamics, in the slowest phase of a binary reaction, follow a quasistatic path, which represents a sequence of states of thermal equilibrium at a fixed value of the deformation coordinate. This establishes the use of the statistical particle-evaporation model in the case of dynamical time-evolving systems. Pre- and post-scission multiplicities of neutrons and total multiplicities of protons and α particles in fission reactions of 63Cu+92Mo, 60Ni+100Mo, 63Cu+100Mo at 10 MeV/u and 20Ne+144,148,154Sm at 20 MeV/u are reproduced reasonably well with statistical model calculations performed along dynamic trajectories whose slow stage (from the most compact configuration up to the point where the neck starts to develop) lasts some 35×10−21 s.
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Tässä diplomityössä tavoitteena on selvittää käytännöt ja menetelmät, joilla UPM-Kymmenen sellu-, paperi- ja vaneritehtaat ympäri maailman mittaavat ja laskevat ilmapäästönsä. Tämä tehdään kyselylomakkeella, joka lähetetään tehtaiden ympäristöpäälliköille. Kaikki tärkeimmät seikat ilmapäästöihin liittyen, kuten vaaditut jatkuvatoimiset mittaukset, jaksottaiset mittaukset, raportointikäytäntö, kalibrointi jne. kysytään lomakkeessa. Kyselylomakkeessa painotetaan mittauskäytäntöä sellutehtaissa sekä energiantuotannossa. Saatujen tulosten perusteella annetaan ehdotuksia sekä ohjeita tulevaisuutta varten, jotta mittaustulosten kokoaminen helpottuisi ja vertailukelpoisuus paranisi. Työn kirjallisuusosuudessa selvitetään yleisimmät päästölähteet sekä päästökomponentit paperi –ja selluteollisuudessa. Näiden ei toivottujen yhdisteiden syntymekanismit sekä menetelmät niiden poistamiseksi savukaasuista on myös lyhyesti kuvailtu. Myös erilaiset analysointi- ja näytteenottomenetelmät on kerrottu. Erot tehtaiden ympäristöluvissa käydään läpi, jakaen tehtaat kolmeen maantieteelliseen ryhmään. Lupakäytäntöjen osalta Suomen osuutta on painotettu, sillä UPM-Kymmene on varsin Suomikeskeinen yhtiö tehtaiden lukumääriin ja sijainteihin katsottuna. Viranomaismääräykset sekä päästörajat muutamista tehtaista on esitetty havainnollistaakseen alueellisia eroja.
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The accretion of matter onto a massive black hole is believed to feed the relativistic plasma jets found in many active galactic nuclei (AGN). Although some AGN accelerate particles to energies exceeding 1012 electron volts and are bright sources of very-high-energy (VHE) γ-ray emission, it is not yet known where the VHE emission originates. Here we report on radio and VHE observations of the radio galaxy Messier 87, revealing a period of extremely strong VHE γ-ray flares accompanied by a strong increase of the radio flux from its nucleus. These results imply that charged particles are accelerated to very high energies in the immediate vicinity of the black hole.
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We explore the possible association between the microquasar LSI +61°303 and the EGRET source 2CG 135+01/3EG J0241+6103 by studying, with a detailed numerical model, whether this system can produce the emission and the variability detected by EGRET (>100 MeV) through inverse Compton (IC) scattering. Our numerical approach considers a population of relativistic electrons entrained in a cylindrical inhomogeneous jet, interacting with both the radiation and the magnetic fields, taking into account the Thomson and Klein-Nishina regimes of interaction. Our results reproduce the observed spectral characteristics and variability at γ-rays, thus strengthening the identification of LSI +61°303 as a high-energy γ-ray source.
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Diplomityö tarkastelee säikeistettyä ohjelmointia rinnakkaisohjelmoinnin ylemmällä hierarkiatasolla tarkastellen erityisesti hypersäikeistysteknologiaa. Työssä tarkastellaan hypersäikeistyksen hyviä ja huonoja puolia sekä sen vaikutuksia rinnakkaisalgoritmeihin. Työn tavoitteena oli ymmärtää Intel Pentium 4 prosessorin hypersäikeistyksen toteutus ja mahdollistaa sen hyödyntäminen, missä se tuo suorituskyvyllistä etua. Työssä kerättiin ja analysoitiin suorituskykytietoa ajamalla suuri joukko suorituskykytestejä eri olosuhteissa (muistin käsittely, kääntäjän asetukset, ympäristömuuttujat...). Työssä tarkasteltiin kahdentyyppisiä algoritmeja: matriisioperaatioita ja lajittelua. Näissä sovelluksissa on säännöllinen muistinkäyttökuvio, mikä on kaksiteräinen miekka. Se on etu aritmeettis-loogisissa prosessoinnissa, mutta toisaalta huonontaa muistin suorituskykyä. Syynä siihen on nykyaikaisten prosessorien erittäin hyvä raaka suorituskyky säännöllistä dataa käsiteltäessä, mutta muistiarkkitehtuuria rajoittaa välimuistien koko ja useat puskurit. Kun ongelman koko ylittää tietyn rajan, todellinen suorituskyky voi pudota murto-osaan huippusuorituskyvystä.
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The concentration and ratio of terpenoids in the headspace volatile blend of plants have a fundamental role in the communication of plants and insects. The sesquiterpene (E)-nerolidol is one of the important volatiles with effect on beneficial carnivores for biologic pest management in the field. To optimize de novo biosynthesis and reliable and uniform emission of (E)-nerolidol, we engineered different steps of the (E)-nerolidol biosynthesis pathway in Arabidopsis thaliana. Introduction of a mitochondrial nerolidol synthase gene mediates de novo emission of (E)-nerolidol and linalool. Co-expression of the mitochondrial FPS1 and cytosolic HMGR1 increased the number of emitting transgenic plants (incidence rate) and the emission rate of both volatiles. No association between the emission rate of transgenic volatiles and their growth inhibitory effect could be established. (E)-Nerolidol was to a large extent metabolized to non-volatile conjugates.
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Työn tavoitteena oli selvittää Stora Enso Oyj:llä käytössä olevan Fenix myynnin- ja logistiikanhallintajärjestelmän logistiikkapalveluiden suorituskyky, tuottaa asiakasohjelmisto suorituskykymittauksista muodostuneen tiedon hallintaan sekä tuottaa toteuttamissuunnitelma suorituskyvyn parantamiseksi. Suorituskyky mitattiin käyttämällä TUXEDOn tarjoamia ominaisuuksia. Suorituskykymittausten tuloksien arviointia varten rakennettiin asiakasohjelmisto, jolla pystyttiin tuottamaan tarvittavat yhteenvetotiedot palveluiden kestoista ja rakenteista. Valmiita ratkaisuja ei ollut tarjolla, joten kaikki tarvittavat ohjelmistot on rakennettu osana tätä työtä. Kaikki komponenttiliittymät toteutettiin siten, että myös muitakin kuin logistiikkaan liittyviä palveluita voidaan tarvittaessa mitata. Mittausten tuloksena saatuja keskimääräisiä suoritusaikoja käytettiin hyväksi toteuttamissuunnitelmaa tehdessä. Toteutussuunnitelma sisältää useiden logistiikka-alueiden kehittämisideoita, joilla Fenixin logistiikkapalveluiden suorituskykyä voidaan tehostaa., ja nykyinen järjestelmän toimintanopeus pystytään säilyttämään tulevaisuudessa. Toteuttamissuunnitelmassa esitettyjä toimenpiteitä tullaan toteuttamaan TietoEnator Oyj:ssä vuoden 2003 aikana.
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Quartz tuning forks are extremely good resonators and their use is growing in scanning probe microscopy. Nevertheless, only a few studies on soft biological samples have been reported using these probes. In this work, we present the methodology to develop and use these nanosensors to properly work with biological samples. The working principles, fabrication and experimental setup are presented. The results in the nanocharacterization of different samples in different ambients are presented by using different working modes: amplitude modulation with and without the use of a Phase-Locked Loop (PLL) and frequency modulation. Pseudomonas aeruginosa bacteria are imaged in nitrogen using amplitude modulation. Microcontact printed antibodies are imaged in buffer using amplitude modulation with a PLL. Finally, metastatic cells are imaged in air using frequency modulation.
Resumo:
Dissolved organic matter (DOM) is a complex mixture of organic compounds, ubiquitous in marine and freshwater systems. Fluorescence spectroscopy, by means of Excitation-Emission Matrices (EEM), has become an indispensable tool to study DOM sources, transport and fate in aquatic ecosystems. However the statistical treatment of large and heterogeneous EEM data sets still represents an important challenge for biogeochemists. Recently, Self-Organising Maps (SOM) has been proposed as a tool to explore patterns in large EEM data sets. SOM is a pattern recognition method which clusterizes and reduces the dimensionality of input EEMs without relying on any assumption about the data structure. In this paper, we show how SOM, coupled with a correlation analysis of the component planes, can be used both to explore patterns among samples, as well as to identify individual fluorescence components. We analysed a large and heterogeneous EEM data set, including samples from a river catchment collected under a range of hydrological conditions, along a 60-km downstream gradient, and under the influence of different degrees of anthropogenic impact. According to our results, chemical industry effluents appeared to have unique and distinctive spectral characteristics. On the other hand, river samples collected under flash flood conditions showed homogeneous EEM shapes. The correlation analysis of the component planes suggested the presence of four fluorescence components, consistent with DOM components previously described in the literature. A remarkable strength of this methodology was that outlier samples appeared naturally integrated in the analysis. We conclude that SOM coupled with a correlation analysis procedure is a promising tool for studying large and heterogeneous EEM data sets.
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Myc controls the metabolic reprogramming that supports effector T cell differentiation. The expression of Myc is regulated by the T cell antigen receptor (TCR) and pro-inflammatory cytokines such as interleukin-2 (IL-2). We now show that the TCR is a digital switch for Myc mRNA and protein expression that allows the strength of the antigen stimulus to determine the frequency of T cells that express Myc. IL-2 signalling strength also directs Myc expression but in an analogue process that fine-tunes Myc quantity in individual cells via post-transcriptional control of Myc protein. Fine-tuning Myc matters and is possible as Myc protein has a very short half-life in T cells due to its constant phosphorylation by glycogen synthase kinase 3 (GSK3) and subsequent proteasomal degradation. We show that Myc only accumulates in T cells exhibiting high levels of amino acid uptake allowing T cells to match Myc expression to biosynthetic demands. The combination of digital and analogue processes allows tight control of Myc expression at the population and single cell level during immune responses.
Resumo:
This thesis was made in Naantali plant of Finnfeeds Finland Oy. In this thesis the main study was in reducing, controlling, measuring and processing odour effluents in various methods. Also are considered legislation, marketing issues and environmental requirements of reducing of odour effluents. The literature review introduces odours complications, legislations and various methods of odour removal. There is also a review of volatile organic compounds detection and measuring methods. The experimental section consists TD-GC-MS-measurements and expansive measurements with electronic nose. Electronic nose is a new solution for recognition and measuring industrial odours. In this thesis the electronic nose was adapted into reliable recognition and measuring method. Measurements with electronic nose was made in betaine factory and main targets were odour removal process and other odours from factory. As a result of experimental work with TD-GC-MS-measurements becomes odour compound of 2-and 3- methylbutanal and dimethyldisulfide, which odour is sweet and fug. Extensive study with electronic nose found many developmental subjects. Odour balance measurements of factory and after calculation made adjustment of odour removal process, over all odour effluent to environment will reduce 25 %.
Resumo:
Context.Massive stars form in dense and massive molecular cores. The exact formation mechanism is unclear, but it is possible that some massive stars are formed by processes similar to those that produce the low-mass stars, with accretion/ejection phenomena occurring at some point of the evolution of the protostar. This picture seems to be supported by the detection of a collimated stellar wind emanating from the massive protostar IRAS 16547-4247. A triple radio source is associated with the protostar: a compact core and two radio lobes. The emission of the southern lobe is clearly non-thermal. Such emission is interpreted as synchrotron radiation produced by relativistic electrons locally accelerated at the termination point of a thermal jet. Since the ambient medium is determined by the properties of the molecular cloud in which the whole system is embedded, we can expect high densities of particles and infrared photons. Because of the confirmed presence of relativistic electrons, inverse Compton and relativistic Bremsstrahlung interactions are unavoidable. Aims.We aim to make quantitative predictions of the spectral energy distribution of the non-thermal spots generated by massive young stellar objects, with emphasis on the particular case of IRAS 16547-4247. Methods.We study the high-energy emission generated by the relativistic electrons which produce the non-thermal radio source in IRAS 16547-4247. We also study the result of proton acceleration at the terminal shock of the thermal jet and make estimates of the secondary gamma rays and electron-positron pairs produced by pion decay. Results.We present spectral energy distributions for the southern lobe of IRAS 16547-4247, for a variety of conditions. We show that high-energy emission might be detectable from this object in the gamma-ray domain. The source may also be detectable in X-rays through long exposures with current X-ray instruments. Conclusions.Gamma-ray telescopes such as GLAST, and even ground-based Cherenkov arrays of new generation can be used to study non-thermal processes occurring during the formation of massive stars.
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Quartz Tuning Fork (QTF)-based Scanning Probe Microscopy (SPM) is an important field of research. A suitable model for the QTF is important to obtain quantitative measurements with these devices. Analytical models have the limitation of being based on the double cantilever configuration. In this paper, we present an electromechanical finite element model of the QTF electrically excited with two free prongs. The model goes beyond the state-of-the-art of numerical simulations currently found in the literature for this QTF configuration. We present the first numerical analysis of both the electrical and mechanical behavior of QTF devices. Experimental measurements obtained with 10 units of the same model of QTF validate the finite element model with a good agreement.