Bibliometriikka, kirjastot ja tutkimuksen arviointi

Abstrakti

Suuria ja pieniä kysymyksiä tutkimuksen teosta ja ymmärtämisestä

Kirjallisuusarvostelu

Feministisen maailmanpolitiikan tutkimuksen esiintulo

Kirjallisuusarvostelu

E-aineistojen käytön ja hankinnan tilastot tutkimuksen tiedonlähteinä

Abstrakti

Arkielämän terveystiedon lukutaitoa mittaamassa : kolmen pienimuotoisen tutkimuksen vertailua

Abstrakti

Vascular Function in Chronic Kidney Disease and in Renovascular Disease

Cardiovascular mortality is 15 to 30 times higher in patients with chronic kidney disease than in the age-adjusted general population. Even minor renal dysfunction predicts cardiovascular events and death in the general population. In patients with atherosclerotic renovascular disease the annual cardiovascular event and death rate is even higher. The abnormalities in coronary and peripheral artery function in the different stages of chronic kidney disease and in renovascular disease are still poorly understood, nor have the cardiac effects of renal artery revascularization been well characterized, although considered to be beneficial. This study was conducted to characterize myocardial perfusion and peripheral endothelial function in patients with chronic kidney disease and in patients with atherosclerotic renovascular disease. Myocardial perfusion was measured with positron emission tomography (PET) and peripheral endothelial function with brachial artery flow-mediated dilatation. It has been suggested that the poor renal outcomes after the renal artery revascularization could be due to damage in the stenotic kidney parenchyma; especially the reduction in the microvascular density, changes mainly evident at the cortical level which controls almost 80% of the total renal blood flow. This study was also performed to measure the effect of renal artery stenosis revascularization on renal perfusion in patients with renovascular disease. In order to do that a PET-based method for quantification of renal perfusion was developed. The coronary flow reserve of patients with chronic kidney disease was similar to the coronary flow reserve of healthy controls. In renovascular disease the coronary flow reserve was, however, markedly reduced. Flow-mediated dilatation of brachial artery was decreased in patients with chronic kidney disease compared to healthy controls, and even more so in patients with renovascular disease. After renal artery stenosis revascularization, coronary vascular function and renal perfusion did not improve in patients with atherosclerotic renovascular disease, but in patients with bilateral renal artery stenosis, flow-mediated dilatation improved. Chronic kidney disease does not significantly affect coronary vascular function. On the contrary, coronary vascular function was severely deteriorated in patients with atherosclerotic renovascular disease, possibly because of diffuse coronary artery disease and/or diffuse microvascular disease. The peripheral endothelial function was disturbed in patients with chronic kidney disease and even more so in patient with atherosclerotic renovascular disease. Renal artery stenosis dilatation does not seem to offer any benefits over medical treatment in patients with renovascular disease, since revascularization does not improve coronary vascular function or renal perfusion.

Personality and Depression

The aim of this study was to illustrate the associations of personality variables and depression. The first study population consisted of 50 patients with DSM-IV defined major depressive disorder. Subjects were randomized to receive either fluoxetine medication or short-term psychodynamic psychotherapy. The Hamilton Depression Rating Scale was completed at the baseline and in the follow-up at four months. Baseline mature defense style measured with the Defense Style Questionnaire predicted favourable outcome in the fluoxetine treatment group, whereas no associations were found in psychotherapy group. The Psychological Mindedness Scale scores were not predictive for recovery in patients receiving psychotherapy or medication. The Psychological Mindedness Scale seems not to be useful in selecting optimal treatment in major depressive disorder. Harm Avoidance measured with the Temperament and Character Inventory associated with the baseline severity of the depressive state. In the fluoxetine treatment group high Reward Dependence, high Self-Directedness and high Cooperativeness were predictive for more severe depression in the four months follow-up, whereas no associations were found in the psychotherapy treatment group. It is possible that the result reflects the differences in the placebo response. The second data were derived from the Finnish Public Sector Study. These prospective studies with four years follow-up focused on the predictive value of optimism and pessimism, first, to work disability with a diagnosis of depression lasting at least 90 days and returning to work (N= 38214) , and second, to the likelihood of initiating antidepressant medication treatment lasting at least 100 days and ending the treatment (N= 29930). Results show that low optimism associates with the elevated risk of work disability and higher likelihood of antidepressant use. High pessimism associated with higher likelihood starting at least 100 days antidepressant medication and not stopping medication during the follow up. High pessimism did not seem to predict the entering to depression related work disability, but in the case of disability period it associated with the lower likelihood of returning to work. The thesis shows that personality features play a role as a vulnerability factor, and influence the onset and course of depression. Taking these factors into account more than is currently done may increase the possibilities to enhance the treatment results in depression.

Förverkligande av språkliga rättigheter i Finland. En studie av svenskans ställning i polisens verksamhet i det tvåspråkiga Vanda

Tämän tutkielman aiheena on suomenruotsalaisten kielellisten oikeuksien toteutuminen poliisin toiminnassa. Tutkimuksen lähtökohtana on v. 2004 uudistunut kielilaki, jossa säädetään yhtäläisestä oikeudesta käyttää suomea ja ruotsia Suomen viranomaisissa. Tutkimuksen tarkoituksena on kartoittaa ruotsinkielisten palvelujen nykytilannetta kaksikielisessä Vantaan poliisissa. Tutkimukseen osallistui 27 Vantaan poliisiasemalla työskentelevää poliisia. Tutkimusmenetelmänä käytetään kvalitatiivista teemahaastattelua sekä laajemmalle joukolle suunnattua kyselylomaketta. Kyselylomakkeen avulla kartoitetaan, kuinka usein ja millaisissa tilanteissa poliisit käyttävät ruotsia työssään, ja kuinka he menettelevät asioidessaan ruotsinkielisten kanssa. Lisäksi selvitetään poliisien kielitaidon tasoa ja mahdollisuuksia ruotsin taitojen ylläpitämiseen ja kehittämiseen. Tarkoituksena on myös selvittää, missä määrin poliisit kokevat arvioidun kielitaitonsa vastaavan työelämässä selviytymisen haasteita, sekä heidän näkemyksiään kielellisistä oikeuksista ja virkamiehille asetetuista kielitaitovaatimuksista. Haastattelujen tavoitteena on saavuttaa syväluotaavaa ja kokemuksellista tietoa ruotsin merkityksestä poliisiorganisaatiossa ja poliisin arjessa. Tutkimustulokset osoittavat, että useimmat tutkimukseen osallistuneet poliisit pitävät tärkeänä ruotsinkielisten oikeutta saada palvelua omalla äidinkielellään. Niin poliisijohdon kuin poliisien näkökulmasta keskeistä palvelun järjestämisessä on, ettei asiakkaan oikeusturva kärsi. Poliisit eivät kuitenkaan tavallisesti käytä ruotsia työssään, sillä he arvioivat kohtaavansa ruotsinkielisiä asiakkaita harvoin ja painottavat poliisin ja ruotsinkielisen asiakkaan välisen kanssakäymisen tapahtuvan usein suomeksi. Poliisit arvioivat ruotsin kielen taitonsa yleisesti melko puutteellisiksi ja riittämättömiksi kyetäkseen tarjoamaan hyvätasoista palvelua ruotsiksi. Erityisesti puhuminen ruotsiksi tuottaa monelle vaikeuksia. Tulosten perusteella ehdotamme, että poliisien todelliset ruotsin taidot selvitettäisiin työhönottohaastattelussa. Lisäksi olisi tärkeää, että poliisien kielitaidon tasoa pyrittäisiin tarvittaessa nostamaan poliisitoimen sisäisen jatkokoulutuksen avulla. Mielestämme poliisien kenttätehtävissä tulisi myös sijoittaa vähintään yksi ruotsinkielinen/-kielentaitoinen poliisi joka partioon. Poliisit voisivat myös hyödyntää mahdollisuutta antaa ruotsinkielisen asiakkaan puhua ruotsia ja itse puhua suomea, mikäli tilanne sen käytännössä sallii, ja yhteisymmärrys voidaan näin saavuttaa.

Methods and Models for Accelerating Dynamic Simulation of Fluid Power Circuits

The objective of this dissertation is to improve the dynamic simulation of fluid power circuits. A fluid power circuit is a typical way to implement power transmission in mobile working machines, e.g. cranes, excavators etc. Dynamic simulation is an essential tool in developing controllability and energy-efficient solutions for mobile machines. Efficient dynamic simulation is the basic requirement for the real-time simulation. In the real-time simulation of fluid power circuits there exist numerical problems due to the software and methods used for modelling and integration. A simulation model of a fluid power circuit is typically created using differential and algebraic equations. Efficient numerical methods are required since differential equations must be solved in real time. Unfortunately, simulation software packages offer only a limited selection of numerical solvers. Numerical problems cause noise to the results, which in many cases leads the simulation run to fail. Mathematically the fluid power circuit models are stiff systems of ordinary differential equations. Numerical solution of the stiff systems can be improved by two alternative approaches. The first is to develop numerical solvers suitable for solving stiff systems. The second is to decrease the model stiffness itself by introducing models and algorithms that either decrease the highest eigenvalues or neglect them by introducing steady-state solutions of the stiff parts of the models. The thesis proposes novel methods using the latter approach. The study aims to develop practical methods usable in dynamic simulation of fluid power circuits using explicit fixed-step integration algorithms. In this thesis, twomechanisms whichmake the systemstiff are studied. These are the pressure drop approaching zero in the turbulent orifice model and the volume approaching zero in the equation of pressure build-up. These are the critical areas to which alternative methods for modelling and numerical simulation are proposed. Generally, in hydraulic power transmission systems the orifice flow is clearly in the turbulent area. The flow becomes laminar as the pressure drop over the orifice approaches zero only in rare situations. These are e.g. when a valve is closed, or an actuator is driven against an end stopper, or external force makes actuator to switch its direction during operation. This means that in terms of accuracy, the description of laminar flow is not necessary. But, unfortunately, when a purely turbulent description of the orifice is used, numerical problems occur when the pressure drop comes close to zero since the first derivative of flow with respect to the pressure drop approaches infinity when the pressure drop approaches zero. Furthermore, the second derivative becomes discontinuous, which causes numerical noise and an infinitely small integration step when a variable step integrator is used. A numerically efficient model for the orifice flow is proposed using a cubic spline function to describe the flow in the laminar and transition areas. Parameters for the cubic spline function are selected such that its first derivative is equal to the first derivative of the pure turbulent orifice flow model in the boundary condition. In the dynamic simulation of fluid power circuits, a tradeoff exists between accuracy and calculation speed. This investigation is made for the two-regime flow orifice model. Especially inside of many types of valves, as well as between them, there exist very small volumes. The integration of pressures in small fluid volumes causes numerical problems in fluid power circuit simulation. Particularly in realtime simulation, these numerical problems are a great weakness. The system stiffness approaches infinity as the fluid volume approaches zero. If fixed step explicit algorithms for solving ordinary differential equations (ODE) are used, the system stability would easily be lost when integrating pressures in small volumes. To solve the problem caused by small fluid volumes, a pseudo-dynamic solver is proposed. Instead of integration of the pressure in a small volume, the pressure is solved as a steady-state pressure created in a separate cascade loop by numerical integration. The hydraulic capacitance V/Be of the parts of the circuit whose pressures are solved by the pseudo-dynamic method should be orders of magnitude smaller than that of those partswhose pressures are integrated. The key advantage of this novel method is that the numerical problems caused by the small volumes are completely avoided. Also, the method is freely applicable regardless of the integration routine applied. The superiority of both above-mentioned methods is that they are suited for use together with the semi-empirical modelling method which necessarily does not require any geometrical data of the valves and actuators to be modelled. In this modelling method, most of the needed component information can be taken from the manufacturer’s nominal graphs. This thesis introduces the methods and shows several numerical examples to demonstrate how the proposed methods improve the dynamic simulation of various hydraulic circuits.

Usability of laser–arc hybrid welding processes in industrial applications

Metal industries producing thick sections have shown increasing interest in the laser–arc hybrid welding process because of its clear advantages compared with the individual processes of autogenous laser welding and arc welding. One major benefit of laser–arc hybrid welding is that joints with larger gaps can be welded with acceptable quality compared to autogenous laser welding. The laser-arc hybrid welding process has good potential to extend the field of applications of laser technology, and provide significant improvements in weld quality and process efficiency in manufacturing applications. The objective of this research is to present a parameter set-up for laser–arc hybrid welding processes, introduce a methodical comparison of the chosen parameters, and discuss how this technology may be adopted in industrial applications. The research describes the principles, means and applications of different types of laser–arc hybrid welding processes. Conducted experiment processing variables are presented and compared using an analytical model which can also be used for predictive simulations. The main argument in this thesis is that profound understanding of the advanced technology of laser-arc hybrid welding will help improve the productivity of welding in industrial applications. Based on a review of the current knowledge base, important areas for further research are also identified. This thesis consists of two parts. The first part introduces the research topic and discusses laser–arc hybrid welding by characterizing its mechanism and most important variables. The second part comprises four research papers elaborating on the performance of laser– arc hybrid welding in the joining of metals. The study uses quantitative and qualitative research methods which include in-depth, interpretive analyses of results from a number of research groups. In the interpretive analysis, the emphasis is placed on the relevance and usefulness of the investigative results drawn from other research publications. The results of this study contribute to research on laser–arc hybrid welding by increasing understanding of how old and new perspectives on laser–arc hybrid welding are evidenced in industry. The research methodology applied permits continued exploration of how laser–arc hybrid welding and various process factors influence the overall quality of the weld. Thestudy provides a good foundation for future research, creates improved awareness of the laser–arc hybrid welding process, and assists the metal industry to maximize welding productivity.