Accelerometer-measured physical activity is associated with knee breadth in middle-aged Finns - a population-based study

Background: Articular surface size is traditionally considered to be a relatively stable trait throughout adulthood. Increased joint size reduces bone and cartilage tissue strains. Although physical activity (PA) has a clear association with diaphyseal morphology, the association between PA and articular surface size is yet to be confirmed. This cross-sectional study aimed to clarify the role of moderate-to-vigorous PA (MVPA) in knee morphology in terms of tibiofemoral joint size. Methods: A sample of 1508 individuals from the population-based Northern Finland Birth Cohort 1966 was used. At the age of 46, wrist-worn accelerometers were used to monitor MVPA (≥3.5 METs) during a period of two weeks, and knee radiographs were used to obtain three knee breadth measurements (femoral biepicondylar breadth, mediolateral breadth of femoral condyles, mediolateral breadth of the tibial plateau). The association between MVPA and knee breadth was analyzed using general linear models with adjustments for body mass index, smoking, education years, and accelerometer weartime. Results: Of the sample, 54.8% were women. Most individuals were non-smokers (54.6%) and had 9-12 years of education (69.6%). Mean body mass index was 26.2 (standard deviation 4.3) kg/m2. MVPA was uniformly associated with all three knee breadth measurements among both women and men. For each 60 minutes/day of MVPA, the knee breadth dimensions were 1.8-2.0% (or 1.26-1.42 mm) larger among women (p < 0.001) and 1.4-1.6% (or 1.21-1.28 mm) larger among men (p < 0.001). Conclusions: Higher MVPA is associated with larger tibiofemoral joint size. Our findings indicate that MVPA could potentially increase knee dimensions through similar biomechanical mechanisms it affects diaphyseal morphology, thus offering a potential target in reducing tissue strains and preventing knee problems. Further studies are needed to confirm and investigate the association between articulation area and musculoskeletal health.Peer reviewe

Instrumentation for time-of-flight elastic recoil detection analysis

Time-of-flight elastic recoil detection is an ion beam based method to analyze the elemental composition of thin film samples at different depths. In order to improve the mass resolution and to enable kinematic correction a position sensitive gas ionization chamber energy detector was constructed. This detector along with pre-existing timing detectors were connected to a modern fully digitizing data acquisition setup. This thesis describes the design of these instruments, including all aspects from the mechanical design of the gas ionization detector to the algorithm and software development of the digitizing acquisition setup. The performance of the system has been studied with measurements and Monte Carlo simulations. New methods to study the data acquisition and instrumentation related effects are introduced and these methods are extended to study a proposed low energy time- of-flight ERDA instrument design.Lentoaika-ERDA on ionisuihkupohjainen materiaalianalyysimenetelmä, jonka avulla voidaan ohutkalvonäytteen alkuainepitoisuuksia määrittää eri syvyyksiltä pinnan läheltä. Menetelmällä voidaan määrittää samanaikaisesti kevyiden alkuaineiden, ml. vedyn, ja raskaampien aineiden pitoisuuksia. Menetelmän massaerotuskyvyn parantamiseksi ja kinemaattisen korjauksen mahdollistamiseksi tässä työssä rakennettiin paikkaherkkä kaasun ionisaatioon perustuva energiailmaisin lentoaika-ERDA-laitteiston osaksi. Tämä ilmaisin ja aiemmin rakennetut lentoaikaportit kytkettiin moderniin täysin digitoivaan datankeruuseen. Tässä väitöskirjassa kuvataan näiden laitteiden suunnitteluun vaikuttavia asioita, kaasuionisaatiokammion mekaanisesta suunnittelusta datankeruujärjestelmän algoritmi- ja ohjelmistokehitykseen. Kehitetyn laitteiston suorituskykyä tutkittiin mittausten ja Monte Carlo -tietokonesimulaatiomenetelmien avulla. Väitöskirjassa esitetään uusia menetelmiä datankeruujärjestelmään ja ilmaisimiin liittyvien ilmiöiden mallintamiseksi ja näitä menetelmiä käytetään uuden laitteistokonseptin suunnittelussa

Asiantuntijatyön hankinta : Case Liikenteen turvallisuusvirasto (Trafi)

Tämä kehitystehtävä tehtiin Liikenteen turvallisuusvirastolle. Työn tavoitteena oli määritellä, suunnitella ja toteuttaa asiantuntijan hankintaan liittyvä kilpailutus. Kilpailutuksessa käytetyistä tarjouspyyntömateriaaleista laadittiin sähköiseen kilpailutusjärjestelmään malliasiakirjat muita vastaavia kilpailutuksia varten. Teoreettinen viitekehys koostui tietointensiivisen asiantuntijahankinan määrittelyn kautta parhaiden käytänteiden osalta. Teoria koostui niin julkisella kuin yksityisellä puolella tehtyjen tietointensiivisten hankintojen problematiikasta ja sekä esitetyistä ratkaisuista. Teoreettista viitekehystä tuki valtiohallinnon ohjeistukset hankinnoista sekä voimassa oleva lainsäädäntö. Teoriaosuudessa nostetaan esiin eroavaisuuksia julkisen ja yksityisen puolen osalta, joiden osalta prosessit ovat erilaisia ja itse asiasisältö on sama. Kehitystehtävä toteutettiin toimintatutkimuksena. Nykytilaa kartoitettiin analysoimalla toteutettuja kilpailutuksia, tehtyjä oikaisupyyntöjä ja Markkinaoikeuden päätöstä. Analysoinnin jälkeen lähdettiin luomaan kilpailutusmateriaaleja nojautuen analysoinnin tuloksiin ja hyödyntäen teoria kautta esiin nousseita parhaita käytänteitä – markkinatuntemus, kategorisointi, kokonaiskustannusajattelu ja poikkiorganisatoriset tiimit. Kilpailutuksen toteutuksen jälkeen analysoitiin onnistumista useasta eri näkökulmasta, jotta voitiin todentaa hankinnan onnistuminen. Kilpailutus arvioinnin mukaisesti onnistui hyvin – eri hylkäyksiä, oikaisuvaatimuksia, valituksia, laadukas toimittaja ja kustannushyötytavoitteet toteutuivat. Kilpailutuksen materiaaleja voitiin hyödyntää luotaessa mallidokumentaatiota vastaaviin hankintoihin. Jatkokehityksen osalta tarjoajien palvelumallin kuvausta muutettiin sisäisen kommentoinnin myötä helpommin arvioitavaan suuntaan ilman mielipiteitä.This thesis was written for the Finnish Transport Safety Agency, later Trafi. The purpose was to define, prepare and execute a public tendering for sourcing of consulting services. Materials created in the tendering process were used to create templates in the electronic tendering system, which could be used in similar tenders. The theoretical framework consisted of topic areas from determination of knowledge intensive business services (KIBS) to best practices in KIBS sourcing. The theory was constructed of the problems that both the private and public sectors face in sourcing knowledge intensive business services and proposed solutions. The theoretical framework was supported by the Finnish state’s sourcing handbook and other related information as well as legislation related to public procurement. The differences between public and private procurement were also discussed – processes vary, but the actual context is the same. The approach of this thesis was action research. The current state was defined by analyzing the already carried out tenders, received demands for rectifications and the ruling of the Market Court. After the analysis was done, materials for an upcoming tender were produced. This phase was supported both by the results of the analysis and the best practices identified in the theoretical framework. These best practices were related to knowledge of the markets, categorization, total cost of ownership and cross-functional teams. The success of the tendering process was analyzed from different angles in order to be able to verify it. The analysis showed that the tender was successful – there were no rejections of quotations, no demands for rectifications nor appeals to the Market Court. In addition, the selected supplier was considered as a trustworthy partner and the cost level of the service reached the target. The materials created were usable for creating the tender templates for similar types of tenders in the tendering system. After the evaluation work of the received tenders, internal comments suggested some changes to the service model description document so that in future the evaluation could be done easier and more precise without using opinion as an evaluation tool

Digitizing data acquisition and time-of-flight pulse processing for ToF-ERDA

A versatile system to capture and analyze signals from multi channel plate (MCP) based time-of-flight detectors and ionization based energy detectors such as silicon diodes and gas ionization chambers (GIC) is introduced. The system is based on commercial digitizers and custom software. It forms a part of a ToF-ERDA spectrometer, which has to be able to detect recoil atoms of many different species and energies. Compared to the currently used analogue electronics the digitizing system provides comparable time-of-flight resolution and improved hydrogen detection efficiency, while allowing the operation of the spectrometer be studied and optimized after the measurement. The hardware, data acquisition software and digital pulse processing algorithms to suit this application are described in detail.peerReviewe

Conceptual study of a heavy-ion-ERDA spectrometer for energies below 6 MeV

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Simulations on time-of-flight ERDA spectrometer performance

The performance of a time-of-flight spectrometer consisting of two timing detectors and an ionization chamber energy detector has been studied using Monte Carlo simulations for the recoil creation and ion transport in the sample and detectors. The ionization chamber pulses have been calculated using Shockley-Ramo theorem and the pulse processing of a digitizing data acquisition setup has been modeled. Complete time-of-flight–energy histograms were simulated under realistic experimental conditions. The simulations were used to study instrumentation related effects in coincidence timing and position sensitivity, such as background in time-of-flight–energy histograms. Corresponding measurements were made and simulated results are compared with data collected using the digitizing setup.peerReviewe

Time-of-flight - Energy spectrometer for elemental depth profiling - Jyväskylä design

A new time-of-flight elastic recoil detection spectrometer has been built, and initially the main effort was focused in getting good timing resolution and high detection efficiency for light elements. With the ready system, a 154 ps timing resolution was recorded for scattered 4.8 MeV 4He2+ ions. The hydrogen detection efficiency was from 80% to 20% for energies from 100 keV to 1 MeV, respectively, and this was achieved by having an additional atomic layer deposited Al2O3 coating on the first timing detector’s carbon foil. The data acquisition system utilizes an FPGA-card to time-stamp every time-of-flight and energy event with 25 ns resolution. The different origins of the background events in coincident time-of-flight-energy histograms have been studied and explained. The built system has proved to be able to routinely depth profile films thinner than 10 nm.peerReviewe