320 research outputs found
SyömishÀiriöitÀ sairastaneiden tiedonhankinta virtuaalisista yhteisöistÀ
TiivistelmÀ. TÀmÀn pro gradu -tutkielman aiheena on syömishÀiriöitÀ sairastaneiden tiedonhankinta virtuaalisista yhteisöistÀ. Tutkielman tarkoituksena oli selvittÀÀ, millaisia virtuaaliset yhteisöt ovat tiedonlÀhteinÀ, millaisia informaatiokÀytÀnteitÀ ilmenee sekÀ millaista tieto ja tiedonhankinta on sairauden eri vaiheissa. LisÀksi tavoitteena oli selvittÀÀ, millaista vÀÀrÀÀ ja harhaanjohtavaa tietoa virtuaalisista yhteisöistÀ tunnistettiin sekÀ millaisia kokemuksia nousee esille laihdutuskulttuurista.
Tutkielman aineisto kerÀttiin loka- ja marraskuussa 2018 ja kesÀllÀ 2019 teemahaastatteluilla. Tutkimukseni kohteena oli kaksitoista syömishÀiriöitÀ sairastanutta henkilöÀ, jotka olivat kÀyttÀneet virtuaalisia yhteisöjÀ tiedonhankintaan syömishÀiriöön liittyen. Tutkimusaineisto analysoitiin laadullisin menetelmin teoriaohjaavan sisÀllönanalyysin avulla. Tutkielman toteutuksessa noudatettiin tarkasti tutkimuksen eettisiÀ periaatteita.
Tuloksissa korostui eritoten vertaistiedon ja -tuen suuri merkitys. Vertaistuen osalta ilmeni samoja tuloksia kuin aiemmissa tutkimuksissa (ks. muun muassa Eichhorn 2008). Vertaistietoa esiintyi neutraalin tiedon lisÀksi paranemista tukevana, haitallisena ja pro-anoreksia-ilmiöön liittyvÀnÀ tietona. TiedonhankintakÀytÀnteistÀ nousivat esille eritoten aktiivinen etsintÀ, aktiivinen seuranta ja informaatiosta pidÀttÀytyminen. Tietoa jaettiin vaihtelevasti kommenttien, julkaisujen ja viestien muodossa. Esiin tuli sairauden vaiheen yhteys tiedonhankintaan, minkÀ myötÀ myös kognitiiviset auktoriteetit saattoivat vaihdella. Kognitiivisiksi auktoriteeteiksi tunnistettiin vertaiset, lÀÀketieteelliset julkaisut, jÀrjestöjen asiantuntijat ja hoitotaho. VÀÀrÀÀ tietoa oli kohdattu useammin kuin harhaanjohtavaa tietoa. Misinformaatiota ilmeni epÀtarkkana ja heikosti sovellettavana informaationa, liioitteluna, vÀÀrinkÀsityksinÀ ja voimakkaasti sairauden sanelemina viesteinÀ. Haastatteluissa tuli esille laihdutuskulttuurin ilmeneminen tiedonhankinnan tuloksissa, ja tÀllainen laihduttamista korostava ja normalisoiva uutisointi, mainonta ja keskustelu koettiin haitallisina.
Virtuaaliset yhteisöt vaikuttaisivat olevan merkittÀvÀ ja optimaalinen ympÀristö sekÀ vertaistuen ettÀ tiedon hankinnalle. Yhteisöjen haasteena on kuitenkin haitallisen tiedon mÀÀrÀ, mikÀ saattaa vaikeuttaa toipumista. HedelmÀllisiÀ jatkotutkimuksen aiheita olisikin, miten hyödyllisen ja tukevan vertaistiedon ja -tuen jakaminen onnistuisi parhaiten siten, ettÀ tiedosta tai tuesta ei olisi haittaa. LisÀksi kiinnostava jatkotutkimuksen aihe olisi, miten siirtyminen keskustelufoorumeilta sosiaaliseen median palveluihin on vaikuttanut tiedonhankintaan ja -jakamiseen
Segregation, precipitation, and \alpha-\alpha' phase separation in Fe-Cr alloys: a multi-scale modelling approach
Segregation, precipitation, and phase separation in Fe-Cr systems is
investigated. Monte Carlo simulations using semiempirical interatomic
potential, first-principles total energy calculations, and experimental
spectroscopy are used. In order to obtain a general picture of the relation of
the atomic interactions and properties of Fe-Cr alloys in bulk, surface, and
interface regions several complementary methods has to be used. Using Exact
Muffin-Tin Orbitals method the effective chemical potential as a function of Cr
content (0-15 at.% Cr) is calculated for a surface, second atomic layer and
bulk. At ~10 at.% Cr in the alloy the reversal of the driving force of a Cr
atom to occupy either bulk or surface sites is obtained. The Cr containing
surfaces are expected when the Cr content exceeds ~10 at.%. The second atomic
layer forms about 0.3 eV barrier for the migration of Cr atoms between bulk and
surface atomic layer. To get information on Fe-Cr in larger scales we use
semiempirical methods. Using combined Monte Carlo molecular dynamics
simulations, based on semiempirical potential, the precipitation of Cr into
isolated pockets in bulk Fe-Cr and the upper limit of the solubility of Cr into
Fe layers in Fe/Cr layer system is studied. The theoretical predictions are
tested using spectroscopic measurements. Hard X-ray photoelectron spectroscopy
and Auger electron spectroscopy investigations were carried out to explore Cr
segregation and precipitation in Fe/Cr double layer and Fe_0.95Cr_0.05 and
Fe_0.85Cr_0.15 alloys. Initial oxidation of Fe-Cr was investigated
experimentally at 10^-8 Torr pressure of the spectrometers showing intense
Cr_2O_3 signal. Cr segregation and the formation of Cr rich precipitates were
traced by analysing the experimental spectral intensities with respect to
annealing time, Cr content, and kinetic energy of the exited electron.Comment: 16 pages, 14 figures, 52 reference
Transfer learning for mobile robots
Abstract. In this project transfer learning can be defined as transferring previously learned knowledge to a new environment and making use of it to avoid obstacles. The feasibility of transfer learning was studied in a situation where a robot is given a task to navigate to a user-defined location in a virtual environment without hitting walls and utilizing reinforcement learning to teach the robot, which means that the robot will receive rewards according to the way it moves in the environment and how close it is to the goal location. In this project everything is done and tested in simulation. First the robot is trained in a standard environment, which is a simple hallway. It requires around 4000 iterations for the robot to learn better practices and reach the goal more frequently. When the training is done, the robot is moved to a test environment, which is otherwise similar to the standard one with the exception of a slanted floor, a ramp, in the beginning of the hallway. This proved to be an obstacle that the robot could not overcome without the help of sensor spoofing. Sensor spoofing in this case means inputting fake values to the robotâs laser sensor, which is responsible for detecting obstacles around the robot.
The major target in this research was to transfer the previously learned data from the standard environment to the test environment and utilize sensor spoofing to help the robot overcome the slanted floor and eventually analyze if transfer learning helped the robot perform better. The performance can be compared by looking at the rewards received by the robot, since the robot receives highest rewards when reaching the goal location in the environment and negative rewards when crashing into walls. If transfer learning is beneficial for the robot, the robot should reach the goal point more frequently when making use of previously trained data from the standard environment and sensor spoofing in the test environment, compared to how it performs without them. This was also the result achieved. Even though the performance was not as good as it was without the ramp since without the ramp the robot reached the goal point every time after training around 200 episodes, the performance was better than it was without the trained model and sensor spoofing being used. As a result, transfer learning can be applied in virtual environments for mobile robots under certain restrictions. It can also be utilized in many other cases, this project is just one example.
The codes and files used for this project are available on GitHub at https://github.com/lperala/Transfer_learning_for_mobile_robots.TiivistelmÀ. TÀssÀ projektissa oppimisen siirtÀminen voidaan mÀÀrittÀÀ aiemmin opitun tiedon siirtÀmisenÀ uuteen ympÀristöön ja sen hyödyntÀmisenÀ esteiden vÀlttelyyn. Oppimisen siirtÀmisen toteutettavuutta tutkittiin tilanteessa, jossa robotille on annettu tehtÀvÀ navigoida kÀyttÀjÀn mÀÀrittÀmÀÀn sijaintiin virtuaalisessa ympÀristössÀ osumatta seiniin hyödyntÀen vahvistavaa oppimista robotin opettamiseksi, joka tarkoittaa ettÀ robotti saa positiivisia palkkioita sen mukaan miten se liikkuu ympÀristössÀ ja kuinka lÀhellÀ se on tavoitesijaintia. TÀssÀ projektissa kaikki on tehty ja testattu simulaatiossa. Ensin robotti koulutetaan standardiympÀristössÀ, joka on yksinkertainen kÀytÀvÀ. Robotti tarvitsee noin 4000 toistoa koulutusta, jotta se oppisi liikkumaan paremmin ja saavuttamaan tavoitesijaintinsa useammin. Kun koulutus on tehty, robotti siirretÀÀn testiympÀristöön, joka on muuten samanlainen kuin standardiympÀristö, mutta sisÀltÀÀ kaltevan rampin kÀytÀvÀn alussa. TÀmÀ osottautui esteeksi, jonka yli robotti ei kyennyt liikkumaan ilman sensorin huijaamista. Sensorin huijaaminen tarkoitti tÀssÀ tapauksessa tekaistujen arvojen syöttÀmistÀ robotin lasersensorille, joka vastaa esteiden havaitsemisesta robotin ympÀrillÀ.
Suurin tavoite projektissa oli siirtÀÀ aiemmin opittu data standardiympÀristöstÀ testiympÀristöön ja hyödyntÀÀ sensorin huijaamista auttaakseen robottia ylittÀmÀÀn ramppi ja lopulta analysoida oliko oppimisen siirtÀmisestÀ hyötyÀ robotin suoriutumisen kannalta. Suoriutumista voitiin tarkastella vertaamalla robotin kerÀÀmiÀ palkkioita, koska robotti saa isoimmat palkkionsa saavuttaessaan tavoitesijaintinsa ympÀristössÀ ja taas negatiivisia palkkioita, mikÀli se törmÀÀ seinÀÀn. Jos oppimisen siirtÀminen on hyödyllistÀ, se tarkottaisi ettÀ robotti saavuttaisi tavoitesijainnin useammin kun se hyödyntÀÀ aiemmin opittua dataa kuin jos se suoriutuisi ilman opittua dataa. TÀmÀ oli myös tulos johon pÀÀdyttiin. Vaikka suoriutuminen ei ollut yhtÀ hyvÀÀ kuin ilman ramppia, koska ilman ramppia robotti saavutti tavoitteensa jo 200 koulutusepisodin jÀlkeen, suoriutuminen oli parempaa kuin se oli tÀysin ilman koulutusta ja sensorin huijaamista. Tuloksena, oppimisen siirtÀmistÀ voidaan hyödyntÀÀ virtuaalisissa ympÀristöissÀ mobiileille roboteille tiettyjen rajoituksin. SitÀ voidaan myös hyödyntÀÀ monissa muissakin tapauksissa, tÀmÀ projekti on vain yksi esimerkki.
Projektissa kÀytetyt tiedostot ovat saatavilla GitHubissa osoitteesta https://github.com/lperala/Transfer_learning_for_mobile_robots
L-type calcium channels regulate filopodia stability and cancer cell invasion downstream of integrin signalling
Validation of the Finnish version of the SCOFF questionnaire among young adults aged 20 to 35 years
<p>Abstract</p> <p>Background</p> <p>We tested the validity of the SCOFF, a five-question screening instrument for eating disorders, in a general population sample.</p> <p>Methods</p> <p>A random sample of 1863 Finnish young adults was approached with a questionnaire that contained several screens for mental health interview, including the SCOFF. The questionnaire was returned by 1316 persons. All screen positives and a random sample of screen negatives were invited to SCID interview. Altogether 541 subjects participated in the SCID interview and had filled in the SCOFF questionnaire. We investigated the validity of the SCOFF in detecting current eating disorders by calculating sensitivity, specificity, and positive and negative predictive values (PPV and NPV) for different cut-off scores. We also performed a ROC analysis based on these 541 persons, of whom nine had current eating disorder.</p> <p>Results</p> <p>The threshold of two positive answers presented the best ability to detect eating disorders, with a sensitivity of 77.8%, a specificity of 87.6%, a PPV of 9.7%, and a NPV of 99.6%. None of the subjects with current eating disorder scored zero points in the SCOFF.</p> <p>Conclusion</p> <p>Due to its low PPV, there are limitations in using the SCOFF as a screening instrument in unselected population samples. However, it might be used for ruling out the possibility of eating disorders.</p
Heparin-like Polysaccharides Reduce Osteolytic Bone Destruction and Tumor Growth in a Mouse Model of Breast Cancer Bone Metastasis
PTFE Bypass or Thrupass for Superficial Femoral Artery Occlusion? A Randomised Controlled Trial
AbstractEarly results of a thrupass endograft in the treatment of femoral lesions are promising. Less morbidity and better cost-effectiveness are suggested to be achieved in the treatment of chronic lower limb ischaemia with endovascular treatment compared to surgical treatment.Patients and methodsThis randomised multicentre trial aimed to enroll a group of 60+60 patients for the treatment of 5â25-cm occlusions of superficial femoral artery (SFA) to be followed up for 3 years. Patients were treated either with endoluminal PTFE thrupass (WL Gore & Ass) or with surgical polytetrafluoroethylene (PTFE) bypass to proximal popliteal artery. Primary patency at 3 years was scheduled to be the primary end-point and secondary patency, functional success, costs and quality of life the secondary end-points.ResultsA sample of 100 consecutive SFA occlusions in one of the centres revealed that only 4% of the lesions were amenable for the study. The trial was prematurely terminated due to the results of an interim analysis at the time when 44 patients were recruited: the 1-year primary patency (excluding technical failures) was 48% for thrupass and 95% for bypass (p=0.02). The patency difference in favour of surgical bypass over endovascular thrupass was also sustained after completion of 1-year follow-up, the primary patencies being 46% and 84% at 1 year with grossly equilinear life-table curves thereafter (p=0.18), respectively. The corresponding secondary patencies were 63% and 100% (p=0.05) when excluding technical failures and 58% and 100% (p=0.02) according to intention-to-treat analysis. Secondary outcomes were thus not analysed.ConclusionTreatment of SFA occlusions (TASC IIB and C or Imelda Ia and II) should be done by PTFE bypass rather than by PTFE thrupass, as thrupass is connected with worse early outcome. These results represent only a small category of femoral disease
Body composition as a predictor of physical performance in older age : A ten- year follow-up of the Helsinki Birth Cohort Study
Background: This study assessed how different measures of body composition predict physical performance ten years later among older adults. Methods: The participants were 1076 men and women aged 57 to 70 years. Body mass index (BMI), waist circumference, and body composition (bioelectrical impedance analysis) were measured at baseline and physical performance (Senior Fitness Test) ten years later. Linear regression analyses were adjusted for age, education, smoking, duration of the follow-up and physical activity. Results: Greater BMI, waist circumference, fat mass, and percent body fat were associated with poorer physical performance in both sexes (standardized regression coefficient [beta] from -0.32 to -0.40, p <0.001). Lean mass to BMI ratio was positively associated with later physical performance (beta = 0.31 in men, beta = 0.30 in women, p <0.001). Fat-free mass index (lean mass/height(2)) in both sexes and lean mass in women were negatively associated with later physical performance. Lean mass residual after accounting for the effect of height and fat mass was not associated with physical performance. Conclusions: Among older adults, higher measures of adiposity predicted poorer physical performance ten years later whereas lean mass was associated with physical performance in a counterintuitive manner. The results can be used when appraising usefulness of body composition indicators for definition of sarcopenic obesity.Peer reviewe
Glucose regulation and physical performance among older people: the Helsinki Birth Cohort Study
Aims To assess whether disturbances in glucose regulation are associated with impairment in physical performance during a 10-year follow-up. Methods 475 Men and 603 women from the Helsinki Birth Cohort Study were studied. Glucose regulation was evaluated with a 2-h 75-g oral glucose tolerance test (OGTT) in 2001-2004. Subjects were categorised as having either impaired fasting glucose (IFG), impaired glucose tolerance (IGT), newly diagnosed diabetes or previously known diabetes. Physical performance was assessed approximately 10 years later using the validated senior fitness test (SFT). The relationship between glucose regulation and the overall SFT score was estimated using multiple linear regression models. Results The mean age was 70.8 years for men and 71.0 years for women when physical performance was assessed. The mean SFT score for the whole population was 45.0 (SD 17.5) points. The SFT score decreased gradually with increased impairment in glucose regulation. Individuals with previously known diabetes had the lowest overall SFT score in the fully adjusted model (mean difference compared to normoglycaemic individuals -11.56 points, 95% CI - 16.15 to - 6.98, p <0.001). Both individuals with newly diagnosed diabetes and individuals with IGT had significantly poorer physical performance compared to those with normoglycaemia. No significant difference in physical performance was found between those with IFG and those with normoglycaemia. Conclusions Among older people, impaired glucose regulation is strongly related with poor physical performance. More severe disturbances in glucose regulation are associated with a greater decrease in physical function, indicating the importance of diagnosing these disturbances at an early stage.Peer reviewe
- âŠ