930 resultados para warm current system


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Due to the power of genetics, the mouse has become a widely used animal model in vision research. However, its eyeball has an axial length of only about 2 mm. The present protocol describes how to easily dissect the small rodent eye post mortem. This allows collecting different tissues of the eye, i.e., cornea, lens, iris, retina, optic nerve, retinal pigment epithelium (RPE), and sclera. We further describe in detail how to process these eye samples in order to obtain high‐quality RNA for RNA expression profiling studies. Depending on the eye tissue to be analyzed, we present appropriate lysis buffers to prepare total protein lysates for immunoblot and immuno‐precipitation analyses. Fixation, inclusion, embedding, and cryosectioning of the globe for routine histological analyses (HE staining, DAPI staining, immunohistochemistry, in situ hybridization) is further presented. These basic protocols should allow novice investigators to obtain eye tissue samples rapidly for their experiments.

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Clinical practice guidelines have become an important source of information to support clinicians in the management of individual patients. However, current guideline methods have limitations that include the lack of separating the quality of evidence from the strength of recommendations. The Grading of Recommendations, Assessment, Development and Evaluation (GRADE) working group, an international collaboration of guideline developers, methodologists, and clinicians have developed a system that addresses these shortcomings. Core elements include transparent methodology for grading the quality of evidence, the distinction between quality of the evidence and strength of a recommendation, an explicit balancing of benefits and harms of health care interventions, an explicit recognition of the values and preferences that underlie recommendations. The GRADE system has been piloted in various practice settings to ensure that it captures the complexity involved in evidence assessment and grading recommendations while maintaining simplicity and practicality. Many guideline organizations and medical societies have endorsed the system and adopted it for their guideline processes.

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Tutkimuksen tavoitteena on identifioida yleisimmät toimintolaskennan implementointiin liittyvät ongelmat ja muutosprojektin onnistumiseen vaikuttavat tekijät. Tavoitteena on myös saada kokonaisvaltainen kuva siitä, miksi laskentatoimen muutokset ovat vaikeita implementoida ja miten ihmisten käyttäytyminen vaikuttaa muutosprosessin onnistumiseen. Sekä laskentatoimen että muutosjohtamisen teorioita tarkastellaan laaja-alaisen kuvan saamiseksi siitä, miten ihmisiin ja heidän käyttäytymiseensä liittyvät tekijät vaikuttavat muutosprojektin onnistumiseen tai epäonnistumiseen. Tutkielma käyttää empiirisiä tutkimustuloksia pohjana aiheen tarkastelulle. Tutkielma tarjoaa ehdotuksia tulevaisuuden tutkimukselle liittyen laskentatoimen muutoksen kriittisiin tekijöihin. Kiinnostavimpia alueita tulevaisuuden tutkimukselle on pohtia tarkemmin, miten työntekijöiden oletukset johtajien motiiveista muutoksen takana vaikuttavat muutosvastarintaan sekä miten organisaation rakenne ja muutosvastarintavaikuttavat muutoksen institutionaalistamiseen.

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Pulsewidth-modulated (PWM) rectifier technology is increasingly used in industrial applications like variable-speed motor drives, since it offers several desired features such as sinusoidal input currents, controllable power factor, bidirectional power flow and high quality DC output voltage. To achieve these features,however, an effective control system with fast and accurate current and DC voltage responses is required. From various control strategies proposed to meet these control objectives, in most cases the commonly known principle of the synchronous-frame current vector control along with some space-vector PWM scheme have been applied. Recently, however, new control approaches analogous to the well-established direct torque control (DTC) method for electrical machines have also emerged to implement a high-performance PWM rectifier. In this thesis the concepts of classical synchronous-frame current control and DTC-based PWM rectifier control are combined and a new converter-flux-based current control (CFCC) scheme is introduced. To achieve sufficient dynamic performance and to ensure a stable operation, the proposed control system is thoroughly analysed and simple rules for the controller design are suggested. Special attention is paid to the estimationof the converter flux, which is the key element of converter-flux-based control. Discrete-time implementation is also discussed. Line-voltage-sensorless reactive reactive power control methods for the L- and LCL-type line filters are presented. For the L-filter an open-loop control law for the d-axis current referenceis proposed. In the case of the LCL-filter the combined open-loop control and feedback control is proposed. The influence of the erroneous filter parameter estimates on the accuracy of the developed control schemes is also discussed. A newzero vector selection rule for suppressing the zero-sequence current in parallel-connected PWM rectifiers is proposed. With this method a truly standalone and independent control of the converter units is allowed and traditional transformer isolation and synchronised-control-based solutions are avoided. The implementation requires only one additional current sensor. The proposed schemes are evaluated by the simulations and laboratory experiments. A satisfactory performance and good agreement between the theory and practice are demonstrated.

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Planarian flatworms are an exception among bilaterians in that they possess a large pool of adult stem cells that enables them to promptly regenerate any part of their body, including the brain. Although known for two centuries for their remarkable regenerative capabilities, planarians have only recently emerged as an attractive model for studying regeneration and stem cell biology. This revival is due in part to the availability of a sequenced genome and the development of new technologies, such as RNA interference and next-generation sequencing, which facilitate studies of planarian regeneration at the molecular level. Here, we highlight why planarians are an exciting tool in the study of regeneration and its underlying stem cell biology in vivo, and discuss the potential promises and current limitations of this model organism for stem cell research and regenerative medicine.

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Non-vertebrate chordates, specifically amphioxus, are considered of the utmost interest for gaining insight into the evolutionary trends, i.e. differentiation and specialization, of gene/protein systems. In this work, MTs (metallothioneins), the most important metal binding proteins, are characterized for the first time in the cephalochordate subphylum at both gene and protein level, together with the main features defining the amphioxus response to cadmium and copper overload. Two MT genes (BfMT1 and BfMT2) have been identified in a contiguous region of the genome, as well as several ARE (antioxidant response element) and MRE (metal response element) located upstream the transcribed region. Their corresponding cDNAs exhibit identical sequence in the two lancelet species (B. floridae and B. lanceolatum), BfMT2 cDNA resulting from an alternative splicing event. BfMT1 is a polyvalent metal binding peptide that coordinates any of the studied metal ions (Zn, Cd or Cu) rendering complexes stable enough to last in physiological environments, which is fully concordant with the constitutive expression of its gene, and therefore, with a metal homeostasis housekeeping role. On the contrary, BfMT2 exhibits a clear ability to coordinate Cd(II) ions, while it is absolutely unable to fold into stable Cu (I) complexes, even as mixed species. This identifies it as an essential detoxification agent, which is consequently only induced in emergency situations. The cephalochordate MTs are not directly related to vertebrate MTs, neither by gene structure, protein similarity nor metal-binding behavior of the encoded peptides. The closest relative is the echinoderm MT, which confirm proposed phylogenetic relationships between these two groups. The current findings support the existence in most organisms of two types of MTs as for their metal binding preferences, devoted to different biological functions: multivalent MTs for housekeeping roles, and specialized MTs that evolve either as Cd-thioneins or Cu-thioneins, according to the ecophysiological needs of each kind of organisms.

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Sulautettujen järjestelmien määrä kuten niiden sisältämä älykkyyskin ovat viime vuosina kasvaneet merkittävästi. Sulautettujen ohjelmistojen yleistymistä ja monipuolistumista on edesauttanut sulautettujen laitteistojen prosessointitehon merkittävä kehittyminen, jonka myötä entistä vaativampien ohjelmistojen totetuttaminen sulautetusti on mahdollistunut. Seuraavana sulautettujen järjestelmien kehitysaskeleena on nähtävissä järjestelmien kommunikointikyvyn paraneminen ja siten uusien ja uudentyyppisten sulautettujen ratkaisujen toteuttaminen. VTT on päättänyt tutkia sulautettujen järjestelmien kommunikointia ja kehittää sulautettun protokolla-alustan. Tutkimuksen perusta on CVOPS protokollajärjestelmä, jota jatkokehittämällä pyritään toteuttamaan sulautettu protokollajärjestelmä, µCVOPS. Tässä diplomityössä esitetään kommunikaation sulautetulle järjestelmälle asettamia vaatimuksia, järjestelmän suunnittelu ja prototyypitys sulautetulla laitteistolla. Prototyypitykseen on käytetty sulautettua DragonBall mikrokontrolleria jonka käyttöjärjestelmänä käytettiin sulautettua Linux:a. Tälle alustalle on tehty CVOPS:sta modifioitu versio, jolla µCVOPS:ia pystytään simuloimaan.

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Työn tarkoituksena oli tutkia tuotteen määrittelyyn liittyvää kirjallisuutta ja perehtyä tuotteen määrittelytyön nykytilaan kohdeyrityksessä. Näihin molempiin perustuen muodostetaan prosessimalli tuotteen määrittelytyölle kohdeyrityksessä. Työssä käsitellään prosessijohtamisen pääperiaatteet sekä tuotteen määrittelyä koskevaa kirjallisuutta ja tutkimuksia. Koska kysessä oleva tuote on suurelta osalta ohjelmistotuote, ohjelmistojen suunnittelua, erityisesti ohjelmistovaatimusten hallintaa ja ohjelmistojen määrittelyä, on myös tarkasteltu työssä. Tuotteen määrittelyn haasteita on käsitelty yksityiskohtaisemmin, esimerkiksi dokumentointia, prosessin kulkua, vaatimusten epävakaisuutta sekä muutoksia. Kohdeyritys ja sen ongelmakohdat esitellään ja luodaan prosessimalli. Tämä malli esittelee seuraavat prosessit: raakavaatimusten hallinta -prosessin, roadmapping -prosessin, esisuunnittelu- ja spesifikaatioprosessin ja julkaisun suunnittelu -prosessin. Kaikki nämä ovat vaiheita ennen varsinaisen tuotekehitysprojektin aloittamista. Työssä esitellään myös kolmetasoinen dokumentaatiomalli.

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Diplomityön tavoitteena oli luoda suunnitelma elektronisen hankintatoimen aloittamiseksi, analysoimalla nykyisiä ostoprosesseja ja konsernin laajuista elektronista hankintajärjestelmää. Työ pohjautuu yritysten väliseen elektroniseen kauppaan, elektroniseen hankintatoimeen ja systeemisuunnitteluun liittyvään kirjallisuuteen. Työssä tehdyn suunnitelman tarkoituksena on auttaa Siemens Oy:tä siirtymään uuteen elektroniseen ostotoimintaan. Elektroniselle ostotoiminnalle suunniteltiin tavoitteet ja näitä vastaavat vaatimukset. Elektronisen hankintajärjestelmän analysointi perustuu kirjallisuudessa esitettyihin järjestelmän elinkaari-mallin vaiheisiin. Analysoinnin tarkoituksena oli saada selville järjestelmän soveltuvuus Siemens Oy: n liiketoimintaympäristöön, prosesseihin ja vaatimuksiin. Elektronisen hankintatoiminnan etuja ovat liiketoiminta prosessien johtamisen parantuminen, kustannusten väheneminen sekä taloudellisen suorituskyvyn lisääntyminen. Elektronisen hankintatoiminnan aloittaminen vaatii kuitenkin huolellista suunnittelua. Työssä tehdyt suunnitelmat ja analysoinnit auttavat arvioidessa järjestelmän sopivuutta Siemens Oy: n vaatimuksiin. Oikean ja toimivan järjestelmän valinta ei kuitenkaan takaa elektronisesta hankintatoiminnasta hyötymistä. Tärkeimpiä jatkotoimenpiteitä onkin suorittaa kustannus/hyöty analyysi ja arvioida toimittajien halukkuutta ja kykyjä osallistua markkinapaikkaan.

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This thesis describes the development of a software requirements specification for a user-centric event management system. The system is set to satisfy three goals: adding value for the event attendees, adding value for the event organizer, and reducing the costs of arranging and running an event. The requirements are identified by researching the prescriptive traits of event business and the current state of the case company and its environment. First the professional and human needs for events are scrutinized. Second, some recent reports about the current trends in the event business are reviewed. Then the event life cycle is presented using the model of new service development, and online promotion of events and especially word-of-mouth marketing receive special attention. Events are also regarded from the perspective of social networks and social media. The case company’s current state and its competitors are reviewed to formulate the needs which the system should fulfil. Then the currently available solutions for social media oriented event management are reviewed. The result is a set of functional and non-functional requirements. The functional requirements are categorized into social media, social networking, event personalization, event management, and system administration features. The specified features and non-functional requirements satisfy the three goals set for the system.

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The costs related to the treatment of infected total joint arthroplasties represent an ever groving burden to the society. Different patient-adapted therapeutic options like débridement and retention, 1- or 2-step exchange can be used. If a 2-step exchange is used we have to consider short (2-4 weeks) or long (>4-6 weeks) interval treatment. The Swiss DRG (Diagnose related Groups) determines the reimboursement the hopsital receives for the treatment of an infected total arthroplasty. The review assesses the cost-effectiveness of hospitalisation practices linked to surgical treatment in the two-stage exchange of a prosthetic-joint infection. The aim of this retrospectiv study is to compare the economical impact between a short (2 to 4 weeks) versus a long (6 weeks and above) interval during a two-satge procedure to determine the financial impact. Retrospectiv study of the patients with a two-stage procedure for a hip or knee prosthetic joint infection at CHUV hospital Lausanne (Switzerland) between 2012 and 2013. The review analyses the correlation between the interval length and the length of the hospital stay as well as with the costs and revenues per hospital stay. In average there is a loss of 40′000 Euro per hospitalisation for the treatment of prosthetic joint infection. Revenues never cover all the costs, even with a short interval procedure. This economical loss increases with the length of the hospital stay if a long-term intervall is choosen. The review explores potential for improvement in reimbourement practices and hospitalisation practices in the current Swiss healthcare setting. There should be alternative setups to decrease the burden of medical costs by a) increase the reimboursment for the treatment of infected total joints or by b) splitting the hospital stay with partners (rapid transfer after first operation from center hospital to level 2 hospital and retransfer for second operation to center) in order to increase revenues.

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Extracorporeal assistances are exponentially used for patients, with acute severe but reversible heart or lung failure, to provide more prolonged support to bridge patients to heart and/or lung transplantation. However, experience of use of extracorporeal assistance for pulmonary resection is limited outside lung transplantation. Airways management with standard mechanical ventilation system may be challenging particularly in case of anatomical reasons (single lung), presence of respiratory failure (ARDS), or complex tracheo-bronchial resection and reconstruction. Based on the growing experience during lung transplantation, more and more surgeons are now using such devices to achieve good oxygenation and hemodynamic support during such challenging cases. We review the different extracorporeal device and attempt to clarify the current practice and indications of extracorporeal support during pulmonary resection.

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In the thesis the principle of work of eddy current position sensors and the main cautions that must be taken into account while sensor design process are explained. A way of automated eddy current position sensor electrical characteristics measurement is suggested. A prototype of the eddy current position sensor and its electrical characteristics are investigated. The results obtained by means of the automated measuring system are explained.

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Technical analysis of Low Voltage Direct Current (LVDC) distribution systems shows that in LVDC transmission the customer voltage quality is higher. One of the problems in LVDC distribution networks that converters both ends of the DC line are required. Because of the converters produce not pure DC voltage, but some fluctuations as well, the huge electrolytic capacitors are required to reduce voltage distortions in the DC-side. This thesis master’s thesis is focused on calculating required DC-link capacitance for LVDC transmission and estimation of the influence of different parameters on the voltage quality. The goal is to investigate the methods of the DC-link capacitance estimation and location in the transmission line.

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As part of the Affective Computing research field, the development of automatic affective recognition systems can enhance human-computer interactions by allowing the creation of interfaces that react to the user's emotional state. To that end, this Master Thesis brings affect recognition to nowadays most used human computer interface, mobile devices, by developing a facial expression recognition system able to perform detection under the difficult conditions of viewing angle and illumination that entails the interaction with a mobile device. Moreover, this Master Thesis proposes to combine emotional features detected from expression with contextual information of the current situation, to infer a complex and extensive emotional state of the user. Thus, a cognitive computational model of emotion is defined that provides a multicomponential affective state of the user through the integration of the detected emotional features into appraisal processes. In order to account for individual differences in the emotional experience, these processes can be adapted to the culture and personality of the user.