576 research outputs found
Optical quality assurance of GEM foils
An analysis software was developed for the high aspect ratio optical scanning
system in the Detec- tor Laboratory of the University of Helsinki and the
Helsinki Institute of Physics. The system is used e.g. in the quality assurance
of the GEM-TPC detectors being developed for the beam diagnostics system of the
SuperFRS at future FAIR facility. The software was tested by analyzing five
CERN standard GEM foils scanned with the optical scanning system. The
measurement uncertainty of the diameter of the GEM holes and the pitch of the
hole pattern was found to be 0.5 {\mu}m and 0.3 {\mu}m, respectively. The
software design and the performance are discussed. The correlation between the
GEM hole size distribution and the corresponding gain variation was studied by
comparing them against a detailed gain mapping of a foil and a set of six lower
precision control measurements. It can be seen that a qualitative estimation of
the behavior of the local variation in gain across the GEM foil can be made
based on the measured sizes of the outer and inner holes.Comment: 12 pages, 29 figure
Vastuullisuusluokitusten rooli tilintarkastuksen palkkioiden mÀÀrÀytymisessÀ
TiivistelmĂ€. TĂ€mĂ€n tutkimuksen periaatteellisena tavoitteena on tutkia vastuullisuusluokitusten ja tilintarkastuksen palkkioiden suhdetta toisiinsa. TĂ€mĂ€n lisĂ€ksi tutkimuksessa tulkittiin vastuullisuusraportoinnin laadun merkitystĂ€ edellĂ€ mainittuun selitettĂ€vÀÀn muuttujaan eli tilintarkastuksen palkkioihin nĂ€iden kummankin kuvatessa tilintarkastuskohteen vastuullisuutta eriĂ€vĂ€llĂ€ laajuudella. Tutkimusta keskittyen edellĂ€ mainittujen muuttujien suhteeseen verrattuna tilintarkastuksen palkkioihin ei ole ollut merkittĂ€vĂ€sti, joten tutkimus tuo vastuullisuusraportointiin ja tilintarkastuksen palkkioihin keskittyneeseen tutkimukseen uutta nĂ€kökulmaa. Tutkimusaineistona toimi joukko suomalaisia julkisia ja yksityisiĂ€ yrityksiĂ€ sekĂ€ niiden tilinpÀÀtöksiĂ€ aikavĂ€liltĂ€ 2012â2021, joihin liittyvÀÀ dataa kerĂ€ttiin hyödyntĂ€mĂ€llĂ€ Refinitivin tietokantoja ja erityisesti vastuullisuusdataa sisĂ€ltĂ€vÀÀ Asset4 tietokantaa.
Tutkimuksessa hyödynnettiin tutkimusmetodina usean muuttujan regressioanalyysia, jolloin oli mahdollista arvioida useamman muuttujan roolia ja selittÀvyyttÀ yhtÀ aikaa suhteessa tilintarkastuksen palkkioihin. SekÀ vastuullisuusluokitusten ettÀ vastuullisuusraportoinnin laadun suhteen tuotettiin omat regressiot, joissa ne olivat yhtÀlössÀ kokeellisina selittÀvinÀ muuttujina. Tutkimuksessa hyödynnettiin laaja-alaisesti aiemmissa tutkimuksissa merkitseviksi tilintarkastuksen palkkioiden suhteen nÀhtyjÀ kontrollimuuttujia. NÀistÀ saatujen tulosten pohjalta pyrittiin vastaamaan tutkimuksessa nostettuun avustavaan tutkimuskysymykseen, jossa arvioitiin syitÀ vastuullisuusluokitusten ja tilintarkastuksen palkkioiden suhteen takana tai miksi kyseistÀ suhdetta ei ole tuloksissa nÀhtÀvissÀ.
Tutkimuksen tulokset viittaavat, ettÀ vastuullisuusluokitusten ja tilintarkastuksen palkkioiden vÀlillÀ on nÀhtÀvissÀ lievÀ mutta merkitsevÀ positiivinen suhde. Regressioiden tulosten mukaan yhden yksikön muutos vastuullisuusluokituksissa nÀkyisi yhden prosentin muutoksena tilintarkastuksen palkkioiden mÀÀrÀssÀ. Vastuullisuusraportoinnin laatu sai myös analyysissÀ lievÀsti positiivisen painokertoimen suhteessa selitettÀvÀÀn muuttujaan, mutta tulokset eivÀt olleet tÀmÀn arvon suhteen merkitseviÀ. Kuten suuressa osaa aiemmistakin tilintarkastuksen palkkioihin liittyvissÀ tutkimuksissa tilintarkastuskohteen koko oli merkittÀvin selittÀvÀ muuttuja regressioissa suhteessa tilintarkastuksen palkkioihin. Prosentin muutos tilintarkastuskohteen koossa nÀkyisi tulosten mukaan noin puolen prosentin nousuna tilintarkastuksen palkkioissa.
Esitimme mahdollisiksi syiksi vastuullisuusluokitusten ja tilintarkastuksen palkkioiden positiivisen suhteen takana kolme erilaista syytÀ, jotka olivat suurempi sidosryhmien laatuvaatimus, korrelaatio muuttujan ln(Koko) kanssa ja / tai muuttujien vÀlinen kÀÀnteinen kausaliteetti. Tutkimus viittaa vastuullisuuden olemassa olevaan mutta todennÀköisesti epÀsuoraan rooliin tilintarkastuksen palkkioiden muodostumisessa. Aihe kuitenkin vaatii todennÀköisesti jatkotutkimuksia konkreettisen yhteyden varmentamiseksi ja tÀmÀn tulkinnan parantamiseksi muuttujien vÀlillÀ
No difference in platelet activation or inflammation markers after diets rich or poor in vegetables, berries and apple in healthy subjects
Background: High intake of vegetables and fruits is associated with decreased risk of coronary heart disease. Part of these cardioprotective effects may be mediated via the antithrombotic effects of compounds found in vegetables and fruits, such as flavonoids. Aim of the study: To study the effects of high and low intake of vegetables, berries and apple on platelet function and inflammatory markers. Methods: The study was a randomised, controlled parallel human dietary intervention with healthy female and male volunteers (n = 77, 19â52 y). Nineteen healthy volunteers served as controls. The volunteers consumed one of four strictly controlled isocaloric 6-week diets containing either 810 or 196 g/10 MJ of vegetables, berries and apple and rich either in linoleic acid (11% of energy, en%) or oleic acid (12 en%). Blood and three 24-hour urine samples were collected at the beginning and at the end of the study period for analyses of various markers of platelet function and inflammation. Results: No differences between the treatment groups were seen in platelet count or volume, markers of platelet activation (ex vivo aggregation to ADP and thrombin receptor activating peptide, protein kinase C activity, urinary 2,3-dinor-thromboxane B2 excretion, plasma P-selectin), plasma intercellular adhesion molecule-1, sensitive C-reactive protein, or antiphospholipid antibodies. Conclusions: The results indicate that in healthy volunteers 6-week diets differing markedly in the amounts of vegetables, berries and apple do not differ in their effects on platelets or inflammation.Peer reviewe
Fiktionkirjoittajien tiedonhankintakÀyttÀytyminen
TiivistelmÀ. TÀmÀn tutkimuksen tarkoituksena on selvittÀÀ fiktionkirjoittajien yleisimpiÀ tiedonhankintastrategioita, todennÀköisempiÀ tiedonlÀhteitÀ, sekÀ miksi he valitsivat kÀyttÀmÀnsÀ strategiat ja tiedonlÀhteet. LisÀksi olen kiinnostunut siitÀ miksi taustatutkimus koetaan tÀrkeÀksi fiktionkirjoittamisessa. LÀhestymistapa on laadullinen, ja aineiston kerÀÀmiseksi haastattelin neljÀÀ harrastajafiktionkirjoittajaa heidÀn tiedonhankintatavoistaan puolistrukturoidulla haastattelurungolla
Effects of diet-induced obesity and voluntary wheel running on the microstructure of the murine distal femur
Background.
Obesity and osteoporosis, two possibly related conditions, are rapidly expanding health concerns in modern society. Both of them are associated with sedentary life style and nutrition. To investigate the effects of diet-induced obesity and voluntary physical activity we used high resolution micro-computed tomography (ÎŒCT) together with peripheral quantitative computed tomography (pQCT) to examine the microstructure of the distal femoral metaphysis in mice.
Methods.
Forty 7-week-old male C57BL/6J mice were assigned to 4 groups: control (C), control + running (CR), high-fat diet (HF), and high-fat diet + running (HFR). After a 21-week intervention, all the mice were sacrificed and the left femur dissected for pQCT and ÎŒCT measurements.
Results.
The mice fed the high-fat diet showed a significant weight gain (over 70% for HF and 60% for HFR), with increased epididymal fat pad mass and impaired insulin sensitivity. These obese mice had significantly higher trabecular connectivity density, volume, number, thickness, area and mass, and smaller trabecular separation. At the whole bone level, they had larger bone circumference and cross-sectional area and higher density-weighted maximal, minimal, and polar moments of inertia. Voluntary wheel running decreased all the cortical bone parameters, but increased the trabecular mineral density, and decreased the pattern factor and structure model index towards a more plate-like structure.
Conclusions.
The results suggest that in mice the femur adapts to obesity by improving bone strength both at the whole bone and micro-structural level. Adaptation to running exercise manifests itself in increased trabecular density and improved 3D structure, but in a limited overall bone growthpeerReviewe
Quality assessment of cadmium telluride as a detector material for multispectral medical imaging
Cadmiumtelluride (CdTe) is a high-Z material with excellent photon radiation absorption properties, making it a promising material to include in radiation detection technologies. However, the brittleness of CdTe crystals as well as their varying concentration of defects necessitate a thorough quality assessment before the complex detector processing procedure. We present our quality assessment of CdTe as a detector material for multispectralmedical imaging, a research which is conducted as part of the Consortium Project Multispectral Photon-counting for Medical Imaging and Beam characterization (MPMIB). The aim of the project is to develop novel CdTe detectors and obtain spectrum-per-pixel information that make the distinction between different radiation types and tissues possible. To evaluate the defect density inside the crystals - which can deteriorate the detector performance - we employ infrared microscopy (IRM). Posterior data analysis allows us to visualise the defect distributions as 3D defect maps. Additionally, we investigate front and backside differences of the material with current-voltage (IV) measurements to determine the preferred surface for the pixelisation of the crystal, and perform test measurements with the prototypes to provide feedback for further processing. We present the different parts of our quality assessment chain and will close with first experimental results obtained with one of our prototype photon-counting detectors in a small tomographic setup.Peer reviewe
The prevalence of cardiac complications and their impact on outcomes in patients with non-traumatic subarachnoid hemorrhage.
Subarachnoid hemorrhage (SAH) is a serious condition, and a myocardial injury or dysfunction could contribute to the outcome. We assessed the prevalence and prognostic impact of cardiac involvement in a cohort with SAH. This is a prospective observational multicenter study. We included 192 patients treated for non-traumatic subarachnoid hemorrhage. We performed ECG recordings, echocardiographic examinations, and blood sampling within 24 h of admission and on days 3 and 7 and at 90 days. The primary endpoint was the evidence of cardiac involvement at 90 days, and the secondary endpoint was to examine the prevalence of a myocardial injury or dysfunction. The median age was 54.5 (interquartile range [IQR] 48.0-64.0) years, 44.3% were male and the median World Federation of Neurological Surgeons (WFNS) score was 2 (IQR 1-4). At day 90, 22/125 patients (17.6%) had left ventricular ejection fractionsââ€â50%, and 2/121 patients (1.7%) had evidence of a diastolic dysfunction as defined by mitral peak E-wave velocity by peak e' velocity (E/e')â>â14. There was no prognostic impact from echocardiographic evidence of cardiac complications on neurological outcomes. The overall prevalence of cardiac dysfunction was modest. We found no demographic or SAH-related factors associated with 90 days cardiac dysfunction
Impact of inhaled corticosteroids on growth in children with asthma: systematic review and meta-analysis
Background: Long-term inhaled corticosteroids (ICS) may reduce growth velocity and final height of children with asthma. We aimed to evaluate the association between ICS use of >12 months and growth. Methods: We initially searched MEDLINE and EMBASE in July 2013, followed by a PubMed search updated to December 2014. We selected RCTs and controlled observational studies of ICS use in patients with asthma. We conducted random effects meta-analysis of mean differences in growth velocity (cm/year) or final height (cm) between groups. Heterogeneity was assessed using the I2 statistic. Results: We found 23 relevant studies (twenty RCTs and three observational studies) after screening 1882 hits. Meta-analysis of 16 RCTs showed that ICS use significantly reduced growth velocity at one year follow-up (mean difference -0.48 cm/year (95% CI -0.66 to -0.29)). There was evidence of a dose-response effect in three RCTs. Final adult height showed a mean reduction of -1.20 cm (95% CI -1.90 cm to -0.50 cm) with budesonide versus placebo in a high quality RCT. Meta-analysis of two lower quality observational studies revealed uncertainty in the association between ICS use and final adult height, pooled mean difference -0.85 cm (95% CI -3.35 to 1.65). Conclusion: Use of ICS for >12 months in children with asthma has a limited impact on annual growth velocity. In ICS users, there is a slight reduction of about a centimeter in final adult height, which when interpreted in the context of average adult height in England (175 cm for men and 161 cm for women), represents a 0.7% reduction compared to non-ICS users
Regional trajectories in life expectancy and lifespan variation: Persistent inequality in two Nordic welfare states
An important dimension of inequality in mortality is regional variation. However, studies that investigate regional mortality patterns within and between national and regional borders are rare. We carry out a comparative study of Finland and Sweden: two welfare states that share many attributes, with one exception being their mortality trajectories. Although Finland has risen rapidly in the global life expectancy rankings, Sweden has lost its historical place among the top 10. Using individualâlevel register data, we study regional trends in life expectancy and lifespan variation by sex. Although all regions, in both countries, have experienced substantial improvements in life expectancy and lifespan inequality from 1990â2014, considerable differences between regions have remained unchanged, suggesting the existence of persistent inequality. In particular, Swedishâspeaking regions in Finland have maintained their mortality advantage over Finnishâspeaking regions. Nevertheless, there is some evidence of convergence between the regions of Finland and Sweden
Beneficial effects of running and milk protein supplements on Sirtuins and risk factors of metabolic disorders in rats with low aerobic capacity
Background Physical activity and dietary intake of dairy products are associated with improved metabolic health. Dairy products are rich with branched chain amino acids that are essential for energy production. To gain insight into the mechanisms underlying the benefit of the sub-chronic effects of running and intake of milk protein supplements, we studied Low Capacity Runner rats (LCR), a rodent exercise model with risk for metabolic disorders. We especially focused on the role of Sirtuins, energy level dependent proteins that affect many cellular metabolic processes. Methods Forty-seven adult LCR female rats sedentary or running voluntarily in wheels were fed normal chow and given supplements of either whey or milk protein drink (PD)-supplemented water, or water only for 21 weeks. Physiological responses were measured in vivo. Blood lipids were determined from serum. Mitochondrial markers and Sirtuins (Sirt1-7) including downstream targets were measured in plantaris muscle by western blotting. Results For the first 10 weeks whey-drinking rats ran about 50% less compared to other groups; still, in all runners glucose tolerance improved and triglycerides decreased. Generally, running induced a âŒsix-fold increase in running capacity and a âŒ8% decrease in % body fat. Together with running, protein supplements increased the relative lean mass of the total body weight by âŒ11%. In comparison with sedentary controls, running and whey increased HDL (21%) and whey, with or without running, lowered LDL (â34%). Running increased mitochondrial biogenesis and Sirtuins 3 and 4. When combined with exercise, both whey and milk protein drink induced about a 4-fold increase in Sirt3, compared to runners drinking water only, and about a 2-fold increase compared to the respective sedentary group. Protein supplements, with or without running, enhanced the phosphorylation level of the acetyl-coA-carboxylase, suggesting increased fat oxidation. Both supplemented diets increased Sirt5 and Sirt7 without an additional effect from exercise. Running diminished and PD supplement increased Sirt6. Conclusion We demonstrate in rats new sub-chronic effects of milk proteins on metabolism that involve Sirtuins and their downstream targets in skeletal muscle. The results show that running and milk proteins act on reducing the risk factors of metabolic disorders and suggest that the underlying mechanisms may involve Sirtuins. Notably, we found that milk protein supplements have some favorable effects on metabolism even without running.Peer reviewe
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