992 resultados para special functions


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Freshwater ecosystems and their biodiversity are presently seriously threatened by global development and population growth, leading to increases in nutrient inputs and intensification of eutrophication-induced problems in receiving fresh waters, particularly in lakes. Climate change constitutes another threat exacerbating the symptoms of eutrophication and species migration and loss. Unequivocal evidence of climate change impacts is still highly fragmented despite the intensive research, in part due to the variety and uncertainty of climate models and underlying emission scenarios but also due to the different approaches applied to study its effects. We first describe the strengths and weaknesses of the multi-faceted approaches that are presently available for elucidating the effects of climate change in lakes, including space-for-time substitution, time series, experiments, palaeoecology and modelling. Reviewing combined results from studies based on the various approaches, we describe the likely effects of climate changes on biological communities, trophic dynamics and the ecological state of lakes. We further discuss potential mitigation and adaptation measures to counteract the effects of climate change on lakes and, finally, we highlight some of the future challenges that we face to improve our capacity for successful prediction.

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A Wiener system is a linear time-invariant filter, followed by an invertible nonlinear distortion. Assuming that the input signal is an independent and identically distributed (iid) sequence, we propose an algorithm for estimating the input signal only by observing the output of the Wiener system. The algorithm is based on minimizing the mutual information of the output samples, by means of a steepest descent gradient approach.

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<b> Leukemiaa sairastavien lasten kuumeiset infektiot, erityisesti respiratoriset virusinfektiot</b> <b>Tausta: </b>Hengitysteiden virusinfektiot ovat lasten tavallisimpia sairauksia. Infektiota aiheuttava virus voidaan uusilla menetelmill lyt lhes kaikissa tapauksissa. Leukemiaa sairastavilla lapsilla on perustaudin ja leukemian hoitojen takia tavallista suurempi infektioalttius, ja kuumeilu on tavallista leukemiahoidon aikana. Suurin osa syphoidon aikaisten kuumejaksojen syist j kuitenkin selvittmtt. <b>Tavoitteet:</b> Prospektiivisen 5 vuotta kestneen monikeskustutkimuksen tavoitteena oli etsi uusimmilla mikrobiologisilla menetelmill leukemiaa sairastavien lasten kuumeen syy. Tt varten tutkittiin 16 virusta virusviljelyll, antigeeniosoituksella ja nukleiinihappo-osoituksella. Nytteit otettiin nenst, ulosteesta, virtsasta ja verest. Lisksi tutkittiin MxA-proteiinin kyky osoittaa virusinfektio syplapsella. <b>Tulokset:</b> Tutkimuksen aikana analysoitiin 138 kuumejaksoa 51 leukemialapsella. Kokonaisseuranta-aika oli 1.5 vuotta/lapsi. Kuumejaksojen ilmaantuvuus oli 2.1 jaksoa potilasta kohden suhteutettuna vuoden riskiaikaan. Hengistysteiden virusinfektio voitiin osoittaa 82 kuumejaksossa (59%). Kaksi tai useampi virus lydettiin 12 %:ssa kuumejaksoista. Tavallisimmat virukset olivat rhinovirus (22 %), respiratory syncytial virus eli RS-virus (11 %), human herpes virus 6 (7 %), human bocavirus (5 %), sytomegalovirus (5 %), parainfluenssavirukset (5 %) ja influenssa A -virus (4 %). Kahdelle potilaalle kehittyi pneumonia, muilla oireet olivat lievt. Veriviljely oli positiivinen 19 kuumejaksossa (14 %), ja puolessa tapauksista lydettiin samanaikaisesti respiratorinen virus. MxA proteini ilmeni veren lymfosyyteiss useimmilla virusinfektioon sairastuneilla syplapsilla. <b>Ptelmt:</b> Kuumeiset respiratoriset virusinfektiot ovat tavallisia leukemiaa sairastavilla lapsilla. Infektion oireet ovat tavallisesti vhiset, mutta pienelle osalle voi kehitty veriviljelypositiivinen sepsis tai pneumonia. Kuumeen syy ji selvittmtt vain harvoissa tapauksissa.

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Diplomityn tavoitteena oli antaa kuva vastapainevoimalaitoksen automaation toiminnallisesta suunnittelusta ja soveltaa teoriaa suunnittelemalla toiminnallisuus vesihyrypiirin trkeimmille osuuksille. Tyss on esitelty tyypillinen EPCM-voimalaitosprojekti, joka toteutetaan ulkopuolisen avustajan kanssa tehdyll yhteistyll. Projektin koostuu laitoksen suunnittelu-, rakennus-, asennus- sek kyttnottovaiheista. Huomioitavia asioita ovat mm. projektin budjetti sek aikataulu. Valvonnalla on suuri merkitys projektin onnistumiseen. Lisksi tyss esitelln vastapainevoimalaitoksen vesihyrypiirin prosessi, psdt sek automaatiojrjestelm. Vesihyrypiirill tarkoitetaan syttvesi-, hyry- ja kaukolmpjrjestelm. Psdill pyritn saamaan tuotanto vastaamaan kulutusta. Voimalaitoksen painopiste on kaukolmmn tuottaminen. Automaatiojrjestelmn toiminnoilla tarkoitetaan jrjestelmn suorittamia ohjauksia, stj sek hlytyksi. Toiminnallisessa suunnittelussa tehdn toimilaitteille niin yksittisohjaukset, sdt kuin hlytysluettelot. Tyss tehty toiminnallinen suunnittelu keskittyy erityisesti toimilaitteiden stpiireihin. Stpiirit koostuvat trkeimmist prosessiin liittyvist komponenteista ja stmerkeist. Toiminnallisen suunnittelun dokumentaatioita kytetn automaatiojrjestelmn sovellusohjelmoinnin pohjana.

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An international conference of psychology of religion, organised at the University of Lausanne (Switzerland) on 16 May 2012, took up the theme: "Attachment, psychopathology, and religion". Four speakers were invited: Pehr Granvist, Andrew Gumley, Isabelle Rieben, and Pascal Roman. Their reworked contributions are gathered in this special section of Mental Health, Religion, &amp; Culture. The goal of this special section is to re-examine the whole of this subject of the bond between attachment and religion and/or spirituality in the cases of those persons suffering from mental health disorders.

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One of the most important problems in optical pattern recognition by correlation is the appearance of sidelobes in the correlation plane, which causes false alarms. We present a method that eliminate sidelobes of up to a given height if certain conditions are satisfied. The method can be applied to any generalized synthetic discriminant function filter and is capable of rejecting lateral peaks that are even higher than the central correlation. Satisfactory results were obtained in both computer simulations and optical implementation.

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Macroinvertebrates associated to reed-beds (Phragmites australis) in six shallow natural water bodies along the 220 km of coast of the Comunidad Valenciana (Spain) were studied. These sites were selected to reect different trophic states, but also, and due to the natural variability of mediterranean wetlands, they greatly differ in salinity and hydroperiod. To unify the sampling, reed bed was chosen to provide data from a habitat common to all wetlands, including the most eutrophic ones where submerged macrophytes have disappeared due to water turbidity. Individual submerged stems of Phragmites australis were sampled along with the surrounding water. The animal density found refers to the available stem surface area for colonization. Forty-one taxa were recorded in total, nding Chironomidae to be the most important group, quantitatively and qualitatively. In freshwater sites it was observed an increase in macroinvertebrate"s density at higher trophic states. Nevertheless each studied region had a different fauna. The PCA analysis with macroinvertebrate groups distinguished three types of environment: freshwaters (characterized by swimming insect larvae, collectors and predators, oligochaetes and Orthocladiinae), saline waters (characterized by crustaceans and Chironominae) and the spring pool, which shares both taxa. Chironomids were paid special attention for being the most abundant. A DCA analysis based on the relative abundance of Chironomids reveals salinity as the main characteristic responsible for its distribution, but trophic state and hydrological regime were also shown to be important factors.

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In order to spare functional areas during the removal of brain tumours, electrical stimulation mapping was used in 90 patients (77 in the left hemisphere and 13 in the right; 2754 cortical sites tested). Language functions were studied with a special focus on comprehension of auditory and visual words and the semantic system. In addition to naming, patients were asked to perform pointing tasks from auditory and visual stimuli (using sets of 4 different images controlled for familiarity), and also auditory object (sound recognition) and Token test tasks. Ninety-two auditory comprehension interference sites were observed. We found that the process of auditory comprehension involved a few, fine-grained, sub-centimetre cortical territories. Early stages of speech comprehension seem to relate to two posterior regions in the left superior temporal gyrus. Downstream lexical-semantic speech processing and sound analysis involved 2 pathways, along the anterior part of the left superior temporal gyrus, and posteriorly around the supramarginal and middle temporal gyri. Electrostimulation experimentally dissociated perceptual consciousness attached to speech comprehension. The initial word discrimination process can be considered as an "automatic" stage, the attention feedback not being impaired by stimulation as would be the case at the lexical-semantic stage. Multimodal organization of the superior temporal gyrus was also detected since some neurones could be involved in comprehension of visual material and naming. These findings demonstrate a fine graded, sub-centimetre, cortical representation of speech comprehension processing mainly in the left superior temporal gyrus and are in line with those described in dual stream models of language comprehension processing.